https://ntrs.nasa.gov/search.jsp?R=20100030352 2019-08-30T11:25:06+00:00Z Do you wish you could find a backup system with enough capacity, speed, and sophistica- tion ro backup unattended? fast transfer rates plus the ability to locate and restore your files qUickly - about 75 times faster than normal speed. Could you recreate a document from scratch in the time it takes you ro resrore it? CONFIGURATION RlXlBlUTY. The state-of-the-art liquid crystal display gives you complete drive status information. Command under execution, transfer rate, FAST BAarup, FAST RESTORE. Introducing the CY-8500, the 8mm tape drive that gives you up ro 25 GB on a single tape. And with transfer rates of up ro 90 MB per min- ute, backup takes less time, frees resources, and makes frequent backup Simple and convenient And that's not all. The CY-8500 offers fast file search capability So you get the advantages of high capacity and TRUE "PLuG-AND-PlAY" COMPATIBIUTY WITH: Alliant Alpha Micro Altos Apollo Arix Am Basic-4 Concull1lnl COlMIIVenl DataGeneral DEC 3100 DEC BI-Bus DECHSC DECO-Bus DECTWTA81 DEC Unibus Gould HP IBMASl400 IBM Mainframe IBM RISCI6000 IBMRT IBMSI3B Macintosh McDonnell Douglas NCR Novell DS12 PS/2 PC386Iix PC MS-DOS PC XenixlUnix P8f1ec Plexus Prime Pyramid Sequent Silicon Graphics Sun Unisys WIng IIIdmtlfe tape remaining, and ECC are presented in a clear easy-to-read format By offering such features as data compression - for five times the storage capacity per tape - and data encryption - giving you data access control- the CY-8500 adapts to your company's growing needs. We'll adapt to your site requirements Circle Reader Action No. 411 too, with rack mounting options and cable lengths of up to 80 feet. PROVEN lIOINOLOGY. Best of all, the CY-8500 offers peace of mind. 8mm helical scan technology, designed for data recording, gives you demonstrated performance and reliability ot an adapta- tion of an audio recording format The CY-8500 is part of a complete family of tape backup products that range in capacity from the 150 MB 1,4" cartridge streamer ro the 2 TB cartridge handling system. All backed up by our in-house technical support group and 12-month warranty. For more informa- tion on how you can enjoy the best value in tape backup, call today at 804/873-0900. Rock Landing Corporate Center' 11846 Rock Landing, Newport News, VA 23606' 804/873-0900 . FAX 804/873-8836 ODUCI G GE RIC D6.0 FULL-TIME CADD AVAILABLE FOR PART-TIME WORK. Generic CADOQl 6.0 is a feature-rich computer-aided design and drafting tool for those who want high-end perfonnance at a reasonable price. It's ideal for the busy engineer or de igner who may require CADO just part of the time, Today, Generic CADO offers more power than ever. IMPORT AurocAD FILES DIREC1I.Y With Generic CADO 6.0 you can easily import 20 files from AutoCADQI-based designer and drafting departments, Plus, its fast OXF In/Out feature let you work with a myriad of popular CAD, CAM, CAE and GIS software. NEW FEATURES AND EASE OF USE Generic CADO 6,0 ha a new macro programming fIK~~. Bel ' where Bel denotes the first critical magnetic-flux density, Jc1 denotes the critical current density at the critical magnetic-flux den- sity, Je(B) denotes the critical current den- sity at an axial magnetic-flux density of B, and n is a fitting parameter. By suitable manipulation of the equations and of the data, one can determine both n (Figure 2, top) and Je(B) (Figure 2, bottom). This work was done by Uif E. Israelsson and Donald M. Strayer of Galtech for NASA's Jet Propulsion Laboratory. For further information, Circle 119 on the TSP Insertion of Rod Specimen In Hollow Cylindri cal Specimen TOP VIEW Groove for Hall·Effect Probe SIDE VIEW Figure 1. Magnetic Flux is Compressed into the gap between the superconductive hollow cylinder and the superconductive rod when the rod is inserted in the hole in the cylinder. The Hall-effect probe mea- sures the flux density before and after com- pression. iir3.5 ~ :2 3.0 ~ g 2.5 Vi Sl 2.0 15- E 8 1.5 1.0~_---,~_-,.I:--_""""',--_~ o 5 10 15 20 200 100 N 70 E ~50 iii' ~30 Bt. Gauss Levels off at B = Be1 10 ~0-~5~·1~0-1~5'--~2~0-~~-- B, Gauss Figure 2. The Compression Ratio as a function of the initial magnetic field (up- per plot) appears to fit the mathematical model with n = 1. The critical current den- sity decreases with the magnetic field according to the model (lower piot). These data were obtained with specimens of sintered YBa2 CU30 7' a high-temperature superconductor. Request Gard. In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be ad- dressed to Edward Ansell Director of Patents and Licensing Mail Stop 305-6 California Institute of Technology 1201 East Galifornia Boulevard Pasadena, CA 91125 Refer to NPO-18255, volume and number of this NASA Tech Briefs issue, and the page number. NASA Tech Briefs, January 1992 GOULD Electronics The truth comes out . When we say the Gould TA4000 has all the features you need to get the most accurate trace available, nothing could be closer to the truth. First, Gould signal conditioners. Not only do we offer the industry's widest selection, but also the most accurate. So no matter what your application, you always have the right answer. Second, the dedicated controls. Features like auto-setup and simple trace positioning make start-ups a breeze and minimize operator errors. Then, its 15" printhead records 8 to 24 channels in ... 10,~ either separate or overlapping modes, with no gap in the center. And finally, our exclusive Micropulsing® circuitry maintains brilliant contrast at all chart speeds and every signal frequency. All this, backed by the largest sales and support organization in the recorder industry. Call Gould today at 1-216-328-7000 or for immediate response fill out the coupon and FAX it to us today. And we'll give it to you straight. Please 0 Rush me a TA4000 brochure NTB 1/92 o Have a Gould Sales Representative call Name: ____________ _ Title: _____________ _ Company: ___________ _ Street: ____________ _ City: _______ State: __ Zip: __ Telephone: ___________ _ Send to: Gould Inc., Test and Measurement Group, 8333 Rockslde Road, Valley View, Ohio 44125. F~: (216)328-7400. Circle Reader Action No. 483 ~~ Acoustic Device Would Measure Density of Gas The amplitude of a low-frequency acoustic signal indicates density. NASA's Jet Propulsion Laboratory, Pasadena, California A proposed acoustic sensor 'NOUld meas- ure the density of a flowing gas or mix- ture of gases. The sensor could be con- structed in a variety of configurations for use in monitoring industrial processes. In its basic configuration, the sensor would comprise a narrow tube closed at one end and open at the other, a sound transmitter located in the closed end, and a microphone located part of the way along the tube. The entire sensor, or at least the open end of the tube, would be placed inside the pipe or vessel that con- tains the gas, the density of which is to be measured (see Figure 1). The trans- ducer would produce constant-velocity· amplitude sound waves at a frequency lower than the fundamental resonant fre- quency of the tube. The open end of the sensor tube would be located in a space large enough to make the sound-pressure amplitude at the open end of the tube be zero. That is, for the purpose of mathematical analysis of the acoustic waves in the tube, the free- space boundary condition would be satis- fied. The analysis shows, among other things, that under the free·space boundary condition, and provided that the length of the tube was a small fraction of the acous- tical wavelength , the density of the gas in the tube would be approximately propor- tional to the sound-pressure amplitude at the location of the microphone and in- versely proportional to the frequency. If necessary, the acoustic signal could be extracted from the background noise in the microphone signal by use of a nar- row-band filter. Alternatively a closed-tube version of the sensor (see Figure 2) could be used where too much noise would be picked up through the open end. Where there was insufficient space to satisfy the free-space boundary condition at one end of the tube, two sound transducers would be mounted at opposite ends of the tube and driven in opposite phase. This scheme would make the sound pressures add to zero at the midpoint of the tube, there- by simulating the free-space boundary condition. When the sensor tube was mounted partially or entirely external to the main pipe or vessel , one or more bleed holes Main Flow of Gas Tube Figure 1. The Sensor Tube could be placed inside or partly outside the vessel con- taining the gas to be sampled. Many configurations other than the two shown here could be used. Transmitter 1 I Gas In Thermocouple t Gas Out Transmitter 2 • t Microphone Figure 2. A Closed-Tube Version of the gas-density sensor would include a transmitter at each end of the tube. of small cross section could be used to keep the pressure in the sensor tube the same as in the main pipe or vessel. Such an arrangement could also provide ther- mal isolation to protect the transducers and microphone from high process tem- peratures, but the measurement of densi- ty would then have to be corrected for the difference between the process and meas- urement temperatures. A slight nonlinearity in the density as a function of sound-pressure amplitude could give rise to small errors (typically less than 1 percent) in the density meas- urements. These errors can be essential- ly eliminated by taking account of the dependence of the speed of sound upon temperature and accordingly adjusting the :requency of the sound so that the length of the tube remains a constant fraction of a wavelength. The required frequency, f, for a gas at absolute temperature Tis given by f = fo(T/TJv2, where fo and To denote the frequency and absolute temperature, respectively, at which the sensor would be calibrated. This work was done by Parthasarathy Shakkottai, Eug .Y. Kwack, and Lloyd H. Back of Caltech for NASA's Jet Propul· sion Laboratory. For further information, Circle 4 on the TSP Request Card. This invention is owned by NASA, and a patent application has been filed. In- quiries concerning nonexclusive or ex- clusive license for its commercial develorr ment should be addressed to the Patent Counsel. NASA Resident Office-JPL [see page 14]. Refer to NPO-18155. Measuring Thermal Diffusivity of a High.:rc Superconductor Thermal diffusivity is deduced from propagation of an oscillatory temperature wave. Goddard Space Flight Center, Greenbelt, Maryland A technique for measuring the ther- mal diffusivity of a superconductor of high 34 critical temperature (high Tc) is based on Angstrom's temperature-wave method. In Angstrom's method, the thermal diffusivi- ty of a material is deduced from measure- NASA Tech Briefs, January 1992 Percent 75'l1 50'll 25'l1 lOO'lltll'll 6'l1 3'l1 H I '--~Co"'!IC"!'o·m·p'."-~H~P D!",~ok~P~'o~ DMP·161 Pacesetter f " 2024 DXl "·~'--"I" • release your equipment 15 to 30 times faster than the competition. plotter directly from your PC or Macintosh® with our Hot-To-Plot'M programs. Stares up to four different user configurations. Uses a pen grouping feature for up to eight times the pen life. And cuts and gathers plots in a catch-basket for immediate access. Just load a 150' roll of D- or E-size to double as an affardable, large format scanner. Every Decision Should Be This Easy';- See the new DMP-160 Series taday. And find out what it's like to go home early at night. For information, or the name of your local dealer, contact Houston Instrument today at 1-800-444-3425. HOUSTDN TNSIRUMENT@ " ~·l:-:·~·"'J ~,. ~;~. "(." . A Summagraphics Company " Circle Reader Action No. 550 © 1991 Summagraphics Carparatian. Seymaur, (T 06483. All rights reserved. ments of the propagation of a temperature wave along a rod specimen of the material. The temperature wave could be a steady- state oscillation or a transient; in this case, a steady-state sinusoidal oscillation is chosen. ~ 1-0.188 em -------------r--I The Peltier Junction Generates Tem- perat ure Oscilla- t ions, which propa- gate with attenuation up the specimen. The thermal diffusivity of the specimen is cal- culated from the dis- tance between ther- mocouples and the amplitudes and phases of the oscillatory com- ponents of the thermo- couple readings. The specimen is mounted on a Peltier junction, which, in turn, is mounted on an aluminum heat sink (see figure). Two ther- mocouples are attached to the specimen. Liquid nitrogen flowing through the alu- minum block cools the block, junction, and specimen to a specified steady initial tem- perature. The entire assembly is partially thermally insulated from the environment by mounting it in a vacuum: this enables Designing the Future with Algor Speclmen __ Thermocouples Peltier Junction Liquid Nllrogen In - Aluminum Heat Sink "Algor's FEA Design System has excellent processors, powerful graphics and accuracy at a price that has no match on the market" Stefan 8 . Delin, Ph.D., Sr. Analytical Engineer, Schaeffer Magnetics, Inc., Chatsworth, CA. When Schaeffer Magnetics, a com- pany with 24 years of spaceflight component design experience, was asked to provide actuators for NASA's Flight Telerobotic Servicer (FTS), they turned to Algor engineering software to optimize their design. The FTS is designed to perform a variety of tasks in space, including the assembly and maintenance of spacecraft. The actuators are the 'Joints" for the arms and legs of the FTS. There is no room for compromise in the design of such critical com- ponents for this vital system. That's why Schaeffer Magnetics chose Algor. Algor engineering software is the choice of more than 5,000 engineers worldwide because it's more powerful, easier to use, better supported and less cosUy than competitive systems. High level service at low cost is a key component of Algor's success. Every Algor customer gets a full year of technical support and free upgrades, a monthly newsletter and access to a low cost, long term main- tenance program. Plus, Algor performs training classes and cus- tomized, on-site seminars almost every day. Schaeffer Magnetics is building the future with Algor. You can, too. Phone or fax today for our comprehensive technical literature package. Algor FEA and Design Packages for mM Compatible 286, 386 and 486 Computers and Sun SPARCstations Linear Stress Buckling Electrostatic Nonlinear Stress Random Vibration Vibration & Mode Shape Analysis Parametric and Variational Modeling Computer Aided Design Modal Analysis with Load Stiffening Frequency Response Composite Elements Nonlinear Gap/Cable Steady-State & Transient Heat Transfer Steady-State & Transient Fluid-Flow Modeling & Design Visualization Beam Design Editor Algor, Inc. · 260 Alpha Dr. Pittsburgh, PA 15238 Phone: 412-967-2700. Fax: 41 2-967-2781 In California: 714-755-3207 GSA Contract # GS 00 K 89 AGS 6270 PS01 Sun and SPARCstatlon are Trademarks of Sun Mlcrosystems. 36 Circle Re.der Action No. 361 Liquid Nitrogen Oul - Vacuum Chamber measurements at initial temperatures from 150 to 300 K. Future mounting in a cryostat will enable measurements at initial tem- peratures from 10 to 300 K. The sinusoidal temperature wave is in- troduced into the specimen at its lower end by exciting the Peltier junction with a sinusoidal voltage. The frequency of oscil- lation is typically chosen to be some value between 0.01 and 0.05 Hz. The voltage across each thermocouple is sampled once per second, yielding between 20 and 100 measurements per cycle at each ther- mocouple location. These samples are processed to obtain the amplitudes and phases of the temperature oscillations at each thermocouple. The thermal diffusivity can then be calculated as a function of the ratio between the amplitudes, the dif- ference between the phases, and the dis- tance between the thermocouples. This oscillatory-temperature-wave technique of- fers several advantages: • It eliminates most of the lateral thermal losses and thermal interfaces typical of other longitudinal-heat-flow methods. This feature is necessary to obtain accurate results from specimens of low thermal conductivity. • It is more suitable for use on brittle ma- terials because no pressure is applied to the specimens. In contrast, other long i- tudinal-heaHlow methods require the a~ plication of pressures, which tend to frac- ture the specimens. • The use of an oscillatory temperature wave is made possible by the Peltier junc- tion, which can both heat and cool the specimen. This, in turn, means that there is no net heating of the specimen during a measurement at a specified initial steady temperature. In contrast, other lon- gitudinal-heaHiow methods rely on resis- tive or other "one-way" heating, causing the position-averaged temperature of the specimen to increase in time and thereby degrading the accuracy of the results. This work was done by Charles E. PoNers, Gloria Oh, and Henning Leidecker of Goddard Space Flight Center. For fur- ther information, Circle 155 on the TSP Re- quest Card. GSC-13392 NASA Tech Briefs, January 1992 EXCELLE C E Setting the New Standard in PC Data Acquisition It takes a serious commitment to quality to deliver data acquisition boards that reliably meet the most demanding specifications. The National Instruments AT-MIO-1BF-5 board creates a new standard in excellence with features not found on typical data acquisition boards. These features include: • 200 ksamples/sec sampling rate • Software-configurable analog input and gain • Optimum noise control • True self-calibration • Dither generator for extended resolution • RTSIIZi bus for mUlti- board synchronization AT·MID·16H·9 AT·MID·16H·25 AT·MID·16L·9 AT·MIO·161·25 Lab·PC • Custom instrumentation Pc-LPM.16 amplifier AT.OID.32F AT 16 Sf 801 AT 16 SE a 01 Xl aSE Xl 16SE AT 100.000 12 ±10.±5, 1. 2, 4, 8 01010 100.000 12 ±10,±5, 1, 10. 100. 01010 5011 62.500 12 ±5, O1010 1, 2, 5, 10, 20, 50, 100 SO,OOO 12 ±5, O1010 ±2.5, 0 I. 5 2 Software for programming the AT-MIO-1BF-5 ranges from drivers for Microsoft Windows and DOS to LabWindows® application software. The quality, innovation, and performance of the AT-MIO-1BF-5 sets the new standard in PC data acquisition. For more information on the AT-MIO-1BF-5, 12 a 3 ./ ./ ./ ./ 12 3 ./ ./ ./ ./ 12 24 3 ./ ./ 16t 3 ./ ./ 32 - ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ ./ our complete line of data acquisition boards, signal conditioning products, or software, call us. (512) 794-0100 or (800) 433-3488 (U.S. and Canada) NATIONAL INSTRUIIENTS~ 7lH! Soj'tu.'ar"e 1$ lbe 1"$""""""' · 6504 Bridge Point Parkway Austin, TX 78730-5039 Xl Xl 96 - ./ ./ ./ 24 - ./ ./ ./ ./ PC·OID·96 • Microsoft Windows and r-=PCc..::. O:.:,IO . =..24'-+'-+-+---+-+---+-- --t-t- -r=+-+'-t"-t-'--l---lI-t-'-i DOS driver software pc·nD·10 Xl 16 10 ./ ./ ./ Circle Reader Action No. 691 , SE - Slngle·Ended, 01 - olllerenll.I , 55 - Simuitan •• us S.mpllng t 8 Channels In , 8 Channels Dul AUSTRALIA (03) 879 9422· DENMARK (45) 76 73 22· FRANCE (1) 48 65 33 70 - GERMANY (089) 714 5093 -ITALY (02) 4830 1892 JAPAN (03) 37881921 • NETHERlANDS (01720) 45761 - NORWAY (03) 846 866· SPAIN (908) 604 304 - SWITZERlAND (056) 45 58 80· U.K. (0635) 523 545 PrOducl names listed are trademarks of Ihelr respective manufacturers. Company names listed are trademarks or trade names of their respective companies. CCopyrlght 1991 National Instruments Corporation. All rights reserved. ~J Gel-Filled Holders for Ultrasonic Transducers A transducer is cast in place at the desired angle and position on an object or patient. Langley Research Center, Hampton, Virginia A need exists in medicine and industry for the ability to use ultrasound to look into materials at known fixed angles to the sur- faces while maintaining good acoustical contact and low attenuation. In medical ap- plications, current equipment for doing this includes motor-driven or phased-array sector scanners and various types of fixed- head probes. For industrial use there are variations of the above, with the addition of poly(methyl methacrylate) angle blocks, and squirter systems. In both realms, water baths are used extensively. None of these devices is well suited for use on an ambulatory patient or on a large, irregular, object. In a new technique, an ultrasonic trans- ducer is embedded in a rubbery, castable, low-loss gel to enable the transducer to "look" into the surface of a test object or human body at any desired angle (see fig- ure). The gel is composed of a solution of water and ethylene glycol in a collagen ma- trix. The water, which can be as much as 80 percent of the mixture, is an excellent conductor of ultrasound. The ethylene glycol serves to reduce the rate of evaporation, thereby extending the usable lifespan. The collagen enables the gel to hold its shape. The gel can be made up quickly and in- expensively. Because it is quite fluid when fresh, it can be catalyzed and poured into a mold easily. Once the material has been catalyzed with formaldehyde, it sets up into a solid within a few minutes. The resulting material is not mechanically tough, but it tolerates high temperatures and does not dry. Its acoustic impedance is close to that of water or human tissue. If a reusable assembly is required, a transducer can be secured at the desired angle to the back wall of an enclosure, which can then be filled with the gel. Be- cause of the nondrying characteristic of the material, sealing is not critical. The face of the transducer housing can be fitted with a thin plastic skin to provide resistance to abrasion if a large number of uses is con- templated. For the short term, or to provide better coupling, the skin can be eliminated. To achieve the best possible coupling, or in the case of an irregular surface, the gel can be cast right onto the surface. The enclosure would then take the form of a dam, to be filled from the back. This ar- rangement would simply be peeled off the surface and off the transducer and dis- carded after use. Because the material is somewhat flexible, it is possible to vary the angle of the transducer slightly. The technique described here can pro- vide the total contact of a water bath but can be used on bodies or objects that are too large for water baths, even if they are moving. The technique can provide the look angles of a poly(methyl methacrylate) angle block with the potential of reduced acoustic impedance and refraction. It can be custom-tailored to the task at hand, and the gel is sufficiently inexpensive so that it can be discarded upon completion. It is easy to couple ultrasound in and out of the gel, minimizing the losses and artifacts of other types of standoffs employed in ultra- sonic testing. This work was done by John A. Companion of Planning Research Corp. for Langley Research Center. For further in- formation, Circle 19 on the TSP Request Card. THERMALLY CONDUCTIVE Inquiries concerning rights for the com- mercial use of this invention should be ad- dressed to the Patent Counsel, Langley Research Center [see page 14].Refer to LAR-14027. EPOXY MASTER BOND EP21TCHT-1 EPOXY SYSTEM • Outstanding electrical insulation • Passes NASA outgassing specs • Fast room temperature cure • Heat resistance up to 400°F • Superior environmental protection • High dimensional stability • Convenient packaging For information, call or write : Master Bond Inc., 154 Hobart St. Hackensack, NU 07601 201-343-8983 Master Bond Inc. Adhesives, Sealants & Coatings Circle Reader Action Nt). 619 38 TRANSDUCER MOUNTED AT SPECIFIC ANGLE TO A PLANE SURFACE IN A SHELL WITH FACEPLATE SECTOR SCANNER WITH MOLDED GEL NOSE PIECE TRANSDUCER EMBEDDED IN GEL THAT HAS BEEN CAST ONTO THE SURFACE OF AN IRREGULAR OBJECT The Nondrying, Low-Loss Gel serves as a versatile transmission medium for an ultrasonic transducer. NASA Tech Briefs, January 1992 How to spen ess time thumbing through books and more time tliumbing through results. New Mathcad 3.0 New Mathcad 3. 0 crunches) graphs) updates) andhuments your work in real math notation. We"uwaColpCsos.alSw Hert>rsYl'halNOI'tlIl~'" -~,,- .. -by"'- Automatically. f.~ j cl·c, ~=:..':.."":""-. 1 n L C1 Cz McIIK.ad'<'E~Hendbooh) w-. C1 :: SO 10'" faud L = 2 1IIH I!nd f = New symbolic capabilities are available with a simple menu pick. WeWOf .. fleC\lh!t~ Wp'luse SoNe It's the fast, efficient, com- prehensive way to do technical calculations. Move those reference texts off your desk. Put that calculator back in your pocket. And save that cryptic spreadsheet for your budgets and bookkeeping. It's time to get problems out of the way and make room for answers. With new Mathcad 3.0, the major new upgrade to the world's best-selling math software. It's the all-in-one solution with a singular purpose: to put results in your hands as quickly and thoroughly as possible. C, I 1\ I , hundreds of standard formulas, useful data, even entire calculations. Just click 'n' paste them from a hypertext window into your documents, reaay to use. When you need to simplify a formula, Mathcad's symbolic calclllation capabilities are available with a simple menu pick. There's no arcane programming fanguage to learn, so you can do integrals, Taylor series, intimte sums, and more-all with point 'n' click simplicity. The New Mathcad is a workhorse that handles everything from simple sums to matrix manipulation. Effortlessly, ___ • natuially. __ ;fp, symbolic answer can be used for both numerical calcula- tions or further symbolic transformation. . Simply .type your calculations ~., \\i;"':' _-.:~ mto the live document, ...... ---- ~ You'll also find improved equation editing, enhanced graphing features, and more aocumentation options. So why waste tune workin]with problems1 Join the just like you'd write -t.~ them on a scratch pad. And let Mathcad do the workfor you. It per- forms the calculations. Graphs in 2-D or 3-D. Automatically updates results each time you change a variable. And prints out presentation- quality documents, com- plete with equations in real math notation, even graphics. Newly upgraded Mathcad 3.0 now has Electronic Handbooks for instant access to NTB 22 120,000 users that get results-with Mathcad. • New easy to learn and use Microsoft Windows 3.0 interface • New easy to use symbolic calculations • New Electronic Handbooks with hun- dreds of built-in solutions • Optional Applications Packs with adapt- able templates for Electrical, Mechanical, New Windows 3. 0 interface makes calculation fast and effortless. New Electronic Handbooks give instant access to hundreds of stan- dard formulas. Justclick )n) paste. Civil and Chemical Engineering, Statistics, Advanced Math, and Numerical Methods • Differentials, cubic : .. ""t • .., I • , • I I • I L-J · .t _ 1_"-' , , 1_" , iMmm~ EDITOR'S CHOICE splines, FFfs, matrices and more Mathad2.S • Enhanced 2-D and 3-D graphics 3-~~. • Improved presentation-quality ,--_Bat_of_'_"---l documentatIon • PC DOS, Macintosh~ and Unix" versions also available For a FREE Mathcad demo disk, or upgrade information, call1-800-MATHCAD (or 617-577-1017, Fax 617-577-8829) . Or see your software dealer. Available for IBM· compatibles, Macintosh computelli, and UNIX workstations. TM and ® signify manu&aur] p m,n = ~-.:......----- [ExEy[f(x,y)- ]2 [w(x-m,y-n)- <:w>] ExI;[w(x-m, y-n)<:w>] 2)V' where p(m,n) is the coefficient of correla- tion for a window centered at coordinates m,n in the second image, f(x,Y) is the in- tensity of the second image at point x,y within the window, w(x-m, y-n) = the intensity of the first image at the cor- responding point, is the average in- tensity of the window portion of the second image, and < w> is the average intenSity NASA Tech Briefs, January 1992 of the corresponding part of the first im- age. The position m,n for which p(m,n) is a maximum is the position at which the second image is considered to match the first image best. In the basic approach to velocimetry via digital correlation, systematic matches of intensity samples are extracted from a se- quence of digitized speckle patterns re- corded at different times. Displacements between matched patterns are then divid- ed by the increments of time between ex- posures to obtain a velocity field. When the speckle images are record- ed at equal intervals of time, periodicity and sparseness in the spatial patterns can give rise to false correlation peaks. To sup- press the tendency toward false correla- tions, images can be enriched and partly randomized. The images are still record- ed in pairs with the interval between the first and second images in each pair equal to the interval between the first and sec- ond images in every other pair. However, the pairs are recorded at unequal intervals (see figure). An enriched, randomized first image is synthesized by adding together the intensity patterns of the first images of all the pairs. An enriched, randomized second image is synthesized similarly from the second images of all the pairs (see figure). Then the correlation is performed between the synthetic first and second im- ages to obtain a velocity field more nearly free of errors. This work was done by John A. Gilbert of the University of Alabama in Huntsville and Donald R. Mathys of Marquette Uni- versity for Marshall Space Right Center. For further information, Circle 114 on the TSP Request Card. MFS-26122 Joule-Thomson Cooler Produces Nearly Constant Temperature ~ Variations in atmospheric pressure have little effect on temperature. NASA's Jet Propulsion Laboratory, Pasadena, California An improved Joule-Thomson cooler maintains a nearly constant temperature in its cold head, despite variations in at- mospheric pressure. Coolers of this type could provide the stable low temperatures required for the operation of such devices as tunable diode lasers in laboratory and balloon-borne instruments that detect con- taminants in the atmosphere. The cooler (see figure) is of the "blow- down" type, in which the nitrogen work- ing fluid is supplied as gas pressurized in a tank at ambient temperature. When the main valve is opened, gas at high pressure flows from the tank and is precooled by Filling Port and Safely ---Cl--! Relief Valve Precooling Heal Exchanger Adsorber Demand-Flow Joule-Thomson Valve Cryoslal Vacuum Dewar the ambient atmosphere via an external heat exchanger. The gas then passes through an adsorber, which removes im- purities, before entering the cryostat. In the cryostat, the gas is cooled further in a counterflow recuperative heat exchang- er before expanding through the Joule- Thomson valve, which is essentially an orifice. The isenthalpic expansion in the Joule-Thomson valve causes a decrease in temperature and partial liquefaction of the nitrogen. The liquid nitrogen is vapor- ized by the combined heat load from the Nitrogen- Sioroge Tank (41 MPa) Main Valve Opposed Exhausl Nozzles Absolute- Pressure Relief Valve laser or other devices to be cooled and from parasitic heat leaks. The cold vapor returns through the re- cuperative heat exchanger and is exhaust- ed to the atmosphere. The temperature of the liquid produced by the Joule-Thomson valve is the saturation temperature that corresponds to the exhaust pressure. To prevent fluctuations in atmospheric pres- sure from affecting the exhaust pressure and, thereby, the temperature of the liquid, the exhaust is passed through an absolute- pressure relief valve. PRECISION OPTICS STOCK AND CUSTOM _ Spherical _ Elliptical - Parabolic _ Front/Second Surface, Mirrors - Optical Flats ,....---__ • .",.., - Gold Coated Mirrors - Beam Splitters - Laser Optics - Simple Lenses _ Achromats _ Prisms Recuperative Heat Exchanger Liquid Nllrogen al82 K Free Reference Catalog For Your Technical Library - Fiber Optics - Fresnel Lenses - Magnifiers - Polarlzers _ Filters OPTICAL INSTRUMENTS - Microscopes - Reticles - Collimators Cold Head - Comparators - Lasers The Absolute-Pressure Relief Valve helps to stabilize the temperature of the cold head despite variations in atmospheric pressure. The feedback-controlled electrical heater provides additional stabilization. The demand-flow Joule-Thomson valve requires less nitrogen than does a fixed-orifice Joule-Thomson valve that provides the same amount of cooling. 196 Pages, Over 8000 Products Our new catalog describes one of the largest and most diversified lines in the nation of precision lenses, optics and optical instruments plus many hard-to-find scientific and technical products used in science, industry and by researchers. TEL: 1-609-573-6250 FAX: 1-609-573-6295 Circle Reader Action No. 461 NASA Tech Briefs, January 1992 41 Uke many other blowdown Joule-Thom- son coolers used in scientific, military, and industrial applications, this one includes a thermostatically self-regulating demand- flow mechanism that automatically throt- tles the Joule-Thomson orifice from its wide-open, high-flow-rate position during initial cooldown to a low-flow-rate position during steady operation. The demand-flow configuration reduces the consumption of gas by 65 percent below that of a fixed- orifice Joule-Thomson valve. Low power (0 to 500 mW) is supplied to an electrical heater on the cold head in response to feedback from a tempera- ture sensor on the cold head. This feature provides further stabilization and fine ad- justment of the temperature. In conven- tional Joule-Thomson systems, tempera- tures in steady operation may fluctuate 1 to 2 K, with periodic fluctuations of about 5 K. In this system, temperature drift rates of less than 0.1 mK per minute have been measured. l'J Rhenium-Foil Witness Cylinders This work was done by Steven Bard, Jiunn..Jeng Wu, and Curtis A Trimble of Caltech for NASA's Jet Propulsion lab- oratory. For further information, Circle 112 on the TSP Request Card. This invention is owned by NASA, and a patent application has been filed. In- quiries concerning nonexclusive or ex- clusive license for its commercial develop- ment should be addressed to the Patent Counsel, NASA Resident Office..JPL [see page 14J. Refer to NPQ..18184. A simple device indicates an excess of oxidizer in combustion-chamber flow. NASA's Jet Propulsion Laboratory, Pasadena, California Cylinders of rhenium foil have been used to obtain qualitative indications of locations and amounts of excess oxidizer gas in the oxidizer-and-fuel mixture flow- ing from a bipropellant injector into the combustion chamber of a rocket engine. It is necessary to obtain these indications in design tests because excess oxidizer can damage the wall of the chamber. Rhenium witness foils might also be useful in detecting excess oxygen or other ox- idizers at temperatures between 2,000 and 3,600 ° F (about 1,100 and 2,000 0c) in the burner cores of advanced gas-turbine engines. The rhenium foil, 0.003 in. (0.08 mm) thick, is mounted on a corrosion-resistant steel holder, insulated from the holder by a layer of graphite foil 0.015 in. (0.38 mm) thick (see figure). The inner surface of the rhenium cylinder thus formed serves as a temporary replacement and witness cylinder for that portion of the wall of the combustion chamber in which damage by oxidation was observed previously. Rhenium oxidizes easily at the combus- tion temperature but melts at the much higher temperature of 5,700 OF (about 3,100 0c). The amount of rhenium lost is therefore roughly proportional to the amount of oxidizer at the wall of the com- bustion chamber. A fresh rhenium witness cylinder is installed to evaluate the effect of each change in design upon oxidation of the wall. This work was done by a L. Knight of Aerojet TechSystems for NASA's Jet P~ pulsion Laboratory. For further informa- tion, Circle 103 on the TSP Request Card. NPO-18224 ~------------------------~ Flow - Corrosion· Resistant Steel A Cylindrical Portion of the Wall of the combustion chamber Is replaced with rhenium foil mounted on a holder. The rhenium oxidizes without melting, there- by indicating regions of excess oxidizer in the combustion-chamber flow. l'J Orifices for Fuel-Film Cooling of Combustion Chamber Injected fuel cools the wall and neutralizes excess oxidizer. NASA's Jet Propulsion Laboratory, Pasadena, California A boundary-layer film of fuel flows along the wall of the combustion chamber men- tioned in the preceding article, " Rhenium- Foil Witness Cylinders" (NPO-18224), cool- ing the wall and neutralizing the excess of oxidizer in the vicinity of the wall. This boundary-layer cooling flow enters the chamber through 16 small , replaceable nozzles placed around the periphery of the fuel-and-oxidizer injector. The boundary-layer cooling flow of fuel at each of the 16 locations can be ad· justed, independently of the main injected flow of fuel and oxidizer, by selection of a nozzle that passes a larger or smaller flow. A larger flow at a given location would be selected, for example, if a rhenium-foil hot-fire test like the one described in the preceding article indicated an excess of oxidizer at that location. Each nozzle (see figure) is a small set- screw. An orifice that has a diameter be- tween 0.003 and 0.005 in. (0.08 and 0.13 42 mm) is laser-machined into the setscrew. A small cylindrical screen filter in a cavity upstream of the orifice prevents clogging of the orifice. To distribute the cooling flow more evenly around the circumference of the chamber, the jet of COOling fuel from each such nozzle is aimed at an angled splash plate in the resonator cavity of the A Small Nozzle is made by laser-ma- chining an orifice along the axis of a setscrew. A similar nozzle with a larger or smaller orifice is selected to increase or decrease the flow, respectively. chamber to convert the jet to a fine, atom- ized spray. This work was done by a L Knight of Aerojet Tech Systems for NASA's Jet Pro- pulsion Laboratory. For further informa- tion, Circle 105 on the TSP Request Card. NPO-18225 NASA Tech Briefs, January 1992 How do you connect these together? With the SR630 Thermocouple Monitor. The complete $1495 temperature solution. Temperature monitoring can be a big pain. Different types of thermocouples. Remote locations. Time stamped data logging. Amplified outputs for analog recording and control. Additional voltage inputs. Independent alarms for each sensor. Interfaces to computers and printers. You need it all and you need it under budget. Here's the answer. The SR630 Thermocouple Monitor from SRS. It interfaces 7 types of thermocouples, 16 independent channels of data and easily handles monitoring and logging functions as well as computer interfacing. And the easy to use front panel makes setup a snap. The price? A painless $1495. For more information about the SR630, call SRS at (408) 744-9040. STANFORD RESEARCH SYSTEMS 1290 D Reamwood Avenue, Sunnyvale, CA 94089 SR630 Thermocouple Monitor • 16 input channels • 0.1 degree resolution • B, E, J, K, R, S, and T type thermocouples • °C, OK, OF, and mV de readings • 2000 point non-volatile memory • 4 proportional analog outputs • Audible alarm • GPIB, RS232 and Printer interfaces TEL (408)744-9040 FAX 4087449049 TLX 706891 SRS UD Circle number 8 on Reader Service Card Materials Hardware, Techniques, and Processes 46 Determining the Degree of Graphitization in Carbon Composites 48 Ceramic-fibrous-Insulation Thermal-Protection System Determining the Degree of Graphitization in Carbon Composites An effective solubility parameter is inferred from an infrared reflectance spectrum. NASA's Jet Propulsion Laboratory, Pasadena, California A method for determining the degree of graphitization of a carbon/carbon com- posite material combines an infrared spec- tral experimental technique with a thermo- dynamical theoretical model of solubility. By interrupting the manufacturing process at almost any time and applying the meth· od, one can judge the quality of the com- poSite and monitor the chemical trans- formations that take place during the process. A carbon/carbon composite material is made by pyrolyzing a starting composite of carbon fibers in an organic (often, epoxy or aerosol) matrix. The fibers are relative- Fibers __ 1:: 0> BEFORE PYROLYSIS .0:; ~ "0 Matrix c .9 <3 .' ~ Use Plot-IT® to turn compl icated ideas into comprehensive graphs. Qu ickly f ill" 1\ \ \\\ and easily. - - • Over 60 graph types including 30 • Ultra sharp graphics in full color • Perform spreadsheet tasks with Plot-IT® Worksheet • User-customized FORTRAN functions support • WordPerfect® and Ventura® compatible And remember, we do Windows. Microsoft Windows® operating system,that is. And IBM OS/2. For a free brochure describing all the Plot-IT® features, write or call now. Scientific Programming Enterprises POBox 669 Haslett. Michigan 48840 1517) 339-9859 · FAX 1517) 339·4376 ·"PI IT® stlfNI~ ot-PROGRA~MIf\lG fNHAPRlSfS Circle Reader Action No. 408 Fluxmeters Solid state circuitry provides greater measurement accu- racy, stability, sensitivity , and resolution than other com- monly used flux measurement devices. • Level sensing • IEEE-4888 interface • BCD output • PM/DC, Peak, and AC modes A complete line of search coils and reference standards are available to meet your specific needs. . . -.mag-etc •• _hst:Tt...rnert; ire. 8350 East 48th Street Indianapolis, IN 46226 (317) 545-2102 (800) 243-9120 FAX (317) 549-0502 Circle Reader Action No. 348 73 Mathematics and Information Sciences Hardw ..... Technique •• Book •• nd Report • Comput.r Progr.m. • ndProc .... . 74 VOUS Software Facilitates Development 01 Other Software n Evaluation 01 Threshold Functions lor Searches Among Data 78 Supercomputers 01 the Future 56 Automatic Generation 01 Countdown-Simulating Software 57 Menu-Driven Solver 01 Linear- Programming Problems 74 Computer Ald. Delineation 01 Boundartes In Farmlands 78 Assessment 01 Accuracies 01 Remote-Sensing Maps 57 Software lor Generating Graphs and -;;larts 57 Fault-Tree Compiler Program VOUS Software Facilitates Development of Other Software Graphical functions and editing of programs and other texts are included_ Ames Research Center, Moffett Field. California The Visual Object Oriented Unification System (VOUS) computer program pro vides a facility for the development of other, high-level software. VOUS does not replace, but rather extends, preexisting software tools for the development of other software. It provides a comprehensive, graphical, interactive medium for all phases in the development of a computer code from the early exploration of concepts, through the detailed coding-and-error-checking process, to the final reporting of the finished code and compilation of the in- struction manual for its use. As such, VOUS simplifies and partly automates the programmer's task, even at what hereto- fore has been the pencil-and-paper stage of theoretical analysis and preliminary design with its pseudo code fragments and/or flow charts. The current version of VOUS is the early product of a continuing effort to unify and integrate the various functions provided by such software tools as text editors, graph- ics editors, text formatters, hypertext (in which textual information can be linked to external references and sources), and structureck:lecomposition tools. VOUS uses a very general data structure that can mani- fest itself in a variety of visual forms while enabling the user to create and manipulate easily such abstract objects as large, gen- eral-purpose, hierarchically structured pro- grams, data structures, and documents. From the user's p:lint of view, VOUS func- tions as a "what-you-see-is-what-you-get" 0NYSIWYG) text editor. The user can aug- ment text with pictures, icons, buttons, and structured graphical objects. The text and graphics can be decomposed into logical pages with icons or buttons linking them together. A document can be constructed either in a linear sequence or in a struc- This Nonrectangular Multiple Grid was cre- ated by VOUS. Such grids are particularly useful for the compu- tation of flows in do- mains of arbitrary shape. tured top-down hierarchical fashion, de- pending on its complexity and nature. VOUS can also be used to design tem- plates that can be used in the manner of HyperCard (a type of hypertext) documents to organize information. The unique feature of VOUS is its ability to support objects of various types within a single document. The fundamental paradigm of VOUS is the traversal of a directed graph, the nodes of which represent data objects or opera- tors. Just as a compiler employs a back end that operates on an abstract syntax tree that represents a program, VOUS en- ables the construction and execution (I.e., traversal) of a directed graph of polymor- phic data nodes, the meaning of which graphs can be defined by the user. Such a visual representation can be very useful in the following applications: • A general data-flow programming "lan- guage" in which a variety of existing soft- ware tools can be ordered and connected together graphically. This can provide a procedural specification for combining many large programs together and pass- ing information back and forth between them. • A graphical UNIX "make" facility in which files are represented by icon nodes and dependencies are fooned by linking icons with arcs. Inner nodes can represent "ac- tions" that are invoked to transform de- pendent files into target files. • An n-dimensional "spread sheet" on which polymorphic data cells are formed out of recursive lists rather than only sim- ple arrays. The lists can also represent n- dimensional arrays, the elements of which can, in turn, be other lists or arrays. • Software systems based on the hypertext and HyperCard systems, where textual in- formation can be linked to external refer- ences and sources. • Higher-level shell programming. • Creation of complicated data structures and data sets for existing programs; e.g., composing hierarchical, composite grid structures for use in computational fluid dynamics (see figure). • Outline editors for writing books or other large publications. • Structured painting and drawing programs. This work was done by Joseph Oliger, Ramini Pichumani, and Dulce Ponceleon of Stanford University for Ames Research Center. For further information, Circle 9 on the TSP Request Card. ARC-12571 Computer Aids Delineation of Boundaries in Farmlands Computer-aided delineation is about six times as fast as manual delineation is. Ames Research Center, Moffett Field, California The computer-aided stratification (CAS) procedure is a developmental procedure of image-processing computer equipment 74 and programs that partly automates the delineation of boundaries between areas. These areas, also called "primary samp- ling units," are images of primar.y agricultural lands composed by melding digital Landsat Thematic Mapper data ard NASA Tech Briefs, January 1992 Digital Line Graph data from the United States Geological Survey. As used here, "stratification" denotes the division of land areas into land-cover or land-use groups (called "strata") on the basis of interpreta- tion of the Thematic Mapper imagery. Each primary sampling unit is a group of 6 to 10 smaller areas, called "ultimate sampling units." Primary sampling units are typically bounded by such relatively permanent features as roads and rivers. The CAS output data are used as inputs for subsequent sampling procedures from which statistics on the uses of agricultural lands are developed. The digital Thematic Mapper data on the land area of interest are displayed on a display monitor of 512x512 picture elements of a graphics workstation with an 8-bit intensity in each of the primary colors - red, green, and blue. The range of brightness in each primary color can be adjusted to enhance the subimages of selected land-use features. Next, the Digi- tal Line Graph data are overlaid on the Thematic Mapper imagery for use as refer- ences in delineation. By selecting appli- cable CAS programs, the Digital Line Graph data are edited for display to show such requested features as transportation routes or bodies of water. The CAS soft- ware provides precise registration of the Thematic Mapper imagery and Digital Line Graph data by use of tie points and least- squares transformations. The operator delineates the primary sampling units by using a keyboard and a multi button cursor on a digitizing tablet. The operator types in an identifying num- ber for the primary sampling unit and stratum in question and delineates the area of interest by using the cursor to enclose it in a polygon. As the polygon is closed, the CPS software automatically an- notates it and computes its area. A set of subcommands in one of the CAS pro- grams enables the operator to identify overlaps and gaps between polygons and to correct these deficiencies or otherwise modify the polygons. The polygonal bound- aries and associated data on the primary sampling units are written into a polygon file for subsequent processing. The CAS-assisted procedure was tested by applying it to a three-county area in Missouri (see figure). For comparison, a manual digitization-and-delineation pro- cedure was applied to the same area. The CAS system was found to speed the de- lineation process by a factor of about 6. Because the boundaries of the primary sampling units can be edited easily on the basis of changes in the land-use pattern, the larger area frames that contain the primary sampling units can be updated more frequently. It was also found that the precision of surveys could be enhanced by using CAS because the simultaneous display of the Thematic Mapper and Digital Line Graph data may increase the prob- ability that an operator will assign a pri- mary sampling unit to the correct stratum. This work was done by R. Slye of Ames Research Center, T. Cheng and M. Ma of TGS Technology, Inc., and G. Angelici of Sterling Federal Systems. Further infor- mation may be found in NASA TM-102243 [N90-16313], "Computer-Aided Boundary Delineation of Agricultural Lands." Copies may be purchased [prepayment required] from the National Technical In- formation Service, Springfield, Virginia 22161, Telephone No. (703) 487-4650. Rush orders may be placed for an extra fee by calling (BOO) 336-4700. ARC-12B05 Three Count ies in Missouri for which three partially overlap- ping Thematic Mapper scenes and 7.5'-quad- rangle Digital Line Graph (U.S. Geologi- cal Survey) data were available were divided into primary sampling units by (1) the CAS (computer-aided stratification) proce- dure and (2) a manual digitizing-and delineat- ing procedure. The time required for one operator to complete the task for Macon county was 15 days (manual) vs. only 2.5 day~ (CAS). .--------~ A A ,,'w NASA Tech Briefs, January 1992 .3 Channels for Continuous Measurement .4-112 Digit LCD Display .0.1 % Instrument Accuracy • Bus Controllable (IEEE-488 & RS-232) • Highest Frequency Capability (50 kHz) All F. W.Bell digital gaussmeters are menu- driven, user friendly, microprocsssor based with state-of-the-art ein:ui/1y. Circle Reader Action No. 317 CURRENT SENSORS Ol[f,'.hft'{lflfl'-; • High Frequency • Fast Response «1j.lS) • PC Board or Bulk- head Mou nting • Milliwatt Power Consumption • Low Cost • Wide Bandwidth • Made in U.S.A. For measurements up to 150 amps de or ae peak .. . from de to 200 kHz Circle Reader Action No. 319 CURRENT PROBES HALL GENERA TORS THE GAUSS METER PEOPLE ... ANDMORE 6120 Hanging Moss Rd. Orlando, FL 32807 407-678-6900 Fax: 407-677-5765 Circle Reader Action No. 316 75 Inside every sel of plans, there's a beasl v wailing 10 break'ioose. (;4 " As a design englheer you've probably faced this beast more' times than you care to remem r. Perfectly specified plans meeting , the harsh reall 'es of the manufac- turing environment(, An elegant solution ~botaged by inferior components. Vital sub-assemblies that suddenJy become unavailable. ~eal bea~. And real problems. But there's on~ way you can keep the beasts out of your plans. Attend the atio\,,!al Design Engineering Show & Conference at McConpick Plac~ North in Chicago, Febnlary 24-27, 1992. Over 950 leading rpanufacturers of desigp engineering compo- nents, systeqJ.s and servlces will be here exhibiting over 15,000 1 products. In fact, National Design is the largest OEM event, in North America and over 30,000 of your professional peers are expected to attend. These engineers know that there's no better place and time than National Design to source hard-to-fiAd components, solve some nagging design problems and keep the creative Juices flOwing. You will , too. And while you're there, you can also take advantage of the National Design Conference Program, a full range of informa- tive sessions sponsored by the ASME - such a Concurrent Engineering, the Taguchi Ap- proach and Reverse Engineering. The National Design Engineer- ing Show & Conference is the better way to keep the beast at bay. For your free Show Preview and Conference program, simply clip and mail in the coupon below _ Or call customer services at (203) 964-8287. I--------------~------I I Mail today for more infonnation. I I~ . . I I 0 I want to keep the beasts out of my designs. Design Englneenng ~ I Please send me a National Design Engineering Show & Conference I Show Preview & Conference Program. • February 24-27, 1992 l I 0 I'm interested in exhibiting. McCormick Place North I I Please call me with information. Chicago, IL : I NAME TITLE I 1 COMPANY DIVISION/MAIL STOP I I I I ADDRESS I I CITY/STATE/ZIP I I I I PHONE! FAX XAP I fl I MAil TO: Attendee Fulfillment, National Design, P.O. Box 3833 I L __ 999~mmer Street, Stamfor~T 06905.0833 ________ ...J Circle Reader Action No. 340 Books and Reports These reports, studies, handbooks are avail- able from NASA as Technical Support Pack- ages (TSP's) when a Request Card number is cited; otherwise they are available from the National Technical Information Service. Evaluation of Threshold Functions for Searches Among Data A quantitative measure of the information content of such a function is presented. A paper presents an information-theo- retical analysis of the problem of building a system of inferences from a large col- lection of data (data base). More specifical- ly, the problem is to design searches of the data base for informative conjunctive production rules. The results of this anal- ysis may eventually lead to the design of more-economical and more-effective elec- tronic neural networks that can draw in- ferences from data bases. The concept of the linear threshold function with binary (0,1) weights is in- troduced as the paradigm of a search rule. A Boolean function of this kind implements the logical function that means" X of these N inputs are ON," also called an "(X of N) rule." Two examples include a (1 of N) rule, which is an OR function, and an (N of N) rule, which is an AND function. These rules and functions are compatible with the way people reason in searching among data. In terms of the amount of memory necessary to describe a basic logical unit, an (X of N) rule lies between the general linear threshold function on the one hand and the logical AND and OR functions on the other hand. In this analysis, the J measure is used as a quantitative indication of the informa- tion provided by a linear threshold func- tion with binary weights. The J measure was used originally to quantify the ex- pected change in information provided by a production rule and in that context also serves as a measure of how well such a rule predicts the outputs from the given inputs. There are efficient algorithms for search- ing through a data base for informative conjunctive production rules. The difficul- ty with this approach arises in a data base with noisy input values (or where the un- modeled domain information is effective- ly noise), because in such a case, the use of AND and OR rules requires an exponen- tially large number of units to describe ex- plicitly the possible representations of a single input with the added noise. The number of units is exponential in the ex- pected number of inputs changed by noise. In contrast, a single (X of N) rule cap- NASA Tech Briefs, January 1992 tures the concept of a prototype. A pro- totype together with a Hamming distance defines a class of inputs centered about the prototype. The (X of N) rule defines a prototype with Hamming distance N-X. Prototypes are important units of knowl- edge for several reasons. One is that they are effective in communicating knowledge with humans. Systems that can be under- stood at the lowest level by humans allow for justification of results and for possibly better training procedures. A second ad- vantage is the stability of prototype rules with respect to noisy data. The third advan- BYHA Now, even complex flowcharts that once took days to perfect can be presentation- perfect - in no time! Quick to master and a snap to use, Patton & Patton's flowcharting software is the standard of both large and small businesses around the world - and is available through all major software dealers. See your dealer today! Or, for a "live," interactive demo disk, call: 800·525·0082, ext. 2901. International: 408-778·6557, ext. 2901. tage is that input sample points provide useful starting points for efficient searches for prototype rules with a high J measure. The paper proposes three ways to con- duct an efficient search for the most in- formative rules (the ones that have the highest J measures). The first is based on a process of specialization in which rules of higher order are extensions of rules of lower order. The second is based on a process of generalization in which rules of lower order are developed from pro- totypes defined by input samples. The third involves a recursive procedure in which NON. Software Corporation Excellence in charting the flow of ideas! Works on IBM & 100% compatible PC's, supports CGAJEGANGA and over 150 dot matrix and laser printers, with multiple print densities and 10 font sizes. Creates multi·page charts, portrait or landscape, on most standard paper sizes. Mouse or keyboard controlled. Supports International Characters. IBM is I registared trldemlrk ollntarnltionll Busin ... Mlchina Corporotion. Circle Reader Action No. 499 77 the set of training attributes is added as a set of derived attributes to a number of the most informative rules. This v.ork was done by Rodney M. Goodman, John W Miller, and Padhraic J. Smyth of Caltech for NASA's Jet Propul· sion laboratory. To obtain a copy of the report, " The Information Provided by a Linear Threshold Function With Binary Weights," Circle 40 on the TSP Request Card. NPO-18113 Supercomputers of the Future Key technologies will de- mand speeds and memory capacities that are astounding but nonetheless possible. A report evaluates the supercomputer needs of five key disciplines: turbulence physics, aerodynamics, aerothermodynam- ics, chemistry, and mathematical model- ing of human vision. The report predicts that these fields will require computer speed greater than 1018 floating-point op- erations per second (FLDP's) and memory capacity greater than 1015 words. By way of comparison, today's most advanced computers offer speeds of about 109 FLOP's. Despite the disparity, the report predicts that new parallel computer archi- tectures and new structured numerical methods will make the necessary speed and capacity available in the foreseeable future. Simulations of turbulent flows at modest Reynolds numbers about simple geome- tries will be used routinely to study the basic physics of turbulence and to test theories of turbulence. The direct simula- tion of turbulent flow over a complete air- craft at realistic Reynolds numbers will remain out of reach for years. However, large-eddy simulation, in which only large- scale motions are computed and small- scale motions are approximated by sim- plified mathematical models, will soon be practical for deSigners. Computational aerodynamics is advanc- ing rapidly in both research and design. Reasonably complete three-dimensional mathematical models have already been produced. In the future, combined models of aerodynamics, propulsion, structures, and controls will predict integrated aircraft performance. Computational aerothermodynamics in- volves equations of motion in which the kinetic energy of the vehicle is high enough to cause dissociation, ionization, and electronic excitation of the impinging air or other gas. Such equations are ex- tremely complicated. For example, on the best of today's computers, about 400 h will be needed to calculate the flow around an 78 aeroassisted orbital-transfer vehicle. For the foreseeable future, it will be necessary to rely on empirical models to account for chemical reactions and collision dynam- ics. Computational chemistry on supercom- puters has already made contributions. For example, it is used to predict radiative in- tensity factors, high-temperature transport properties, and rate constants of reactions in flow fields of aerospace vehicles. Within the next decade, computational chemistry will help develop improved catalysts, fuels, and materials. The mathematical modeling of human vision promises practical returns of extra- ordinary value: it could help give robots sight, cure eye diseases, and design dis- plays that optimally exploit the properties of vision. Computational science is being applied to the mathematical modeling of biological visual systems at the cell level and to the development of algorithms to solve specific vision problems. One ma- jor challenge is the complete simulation of the primary visual cortex. Another is the development of a synthetic computer vi- ·sion system for the autonomous guidance of a rotorcraft in low-level flight; this prob- lem is well beyond the capacity of available computers but within the realm of possibility. This VIOrk was done l:tf Victor L Peterson, John Kim, Terry L. Holst, George S. Deiwert, David M. Cooper, Andrew B. Watson, and F. Ron Bailey of Ames Re- search Center. To obtain a copy of the report, "Supercomputer ReqUirements for Selected Disciplines Important to Aero- space," Circle 42 on the TSP Request Card. ARG-12416 Assessment of Accuracies of Remote-Sensing Maps Classifications of clusters of picture elements are sub- jected to statistical tests. A report describes a study of the ac- curacies of the classifications of picture elements in a map derived by digital proc- essing of Landsat-multispectral-scanner imagery of the coastal plain of the Arctic National Wildlife Refuge. A classification of the type in question is one in which each picture element is assigned, according to its spectral characteristics, to a class, called a "stratum" in statistical parlance, that represents one of several (in this case, twelve) predetermined categories of vegetation or land cover. The accuracies of portions of the map are analyzed with the help of a statistical sampling procedure called "stratified plur- ality sampling," in which all the picture ele- ments in a given cluster are classified in the stratum to which a plurality of them belong. The strata thus derived then pro- vide the statistical population from which stratified samples are taken and compared with field surveys to determine the ac- curacies of the classifications. The motiva- tion for this procedure is that picture ele- ments in classes that occur infrequently are more likely to be sampled in their plur- ality classes than they would be in ordinary stratified-cluster sampling, wherein the strata are usually selected by visual in- spection of imagery or of maps (called "base maps") made previously by means independent of the Landsat imagery. The results of the statistical analysis are tabulated as percentages of correct classi- fications overall as well as per category of land cover, with associated confidence intervals. The authors conclude that al- though the percentages correct were dis- appointingly low for most categories, the study was useful in highlighting sources of errors in classification and in demon- strating the inadequacies of stratified plur- ality sampling. Spectral confusion among categories, spatially complicated mixtures of land covers of different categories, in- complete descriptions of the categories, and changes in land cover between the time of the classification and the time of this study are found to be sources of er- rors in the classification. Especially in areas like the Arctic coastal plain, which contains spatially complicated mixtures, the fixed· size and shape of the picture elements in the Landsat format and the binary choice of "correct" or "incorrect" for each picture element are sources of much of the error. The appropriate defini- tion of a category is relative to the scale at which it makes sense, and this scale may not coincide with the scale of a pic- ture element. The dependence of the de- finition of a category on scale causes such errors of classification as inclusions and confusions among picture elements, and can be analyzed correctly only by use of classification schemes more sophisticat- ed than are those that operate on one pic- ture element at a time. The adequacy of the stratified-plurality-sampling scheme used was found to be limited by the insuf- ficient numbers of samples, caused by the insufficiency of resources available for field surveys. This v.ork was done by Don H. Card of Ames Research Center and Lau[ence L. Strong of 7GS Technology. Further informa- tion may be found in NASA TM-101042 [N89-17339], ''Accuracy Assessment, Using Stratified Plurality Sampling, of Portions of a Landsat Classification of the Arctic Na- tional Wildlife Refuge Coastal Plain." Copies may be purchased [prepayment required] from the National Technicallnfor- mation Service, Springfield, Virginia 22161, Telephone No. (703) 487-4650. Rush orders may be placed for an extra fee by calling (800) 336-4700. ARC-12371 NASA Tech Briefs, January 1992 Life Sciences Hardware, Techniques, and Processes 79 Thin-Membrane Sensor With Biochemical Switch 80 Tissue-Simulating Gel for Medical Research Thin-Membrane Sensor With Bio.chemical Switch The sensor could be used as an alarm for chemical or biological materials. Marshall Space Flight Center, Alabama A modular sensor electrochemically de- tects a chemical or biological agent, indi- cating the presence of the agent via a gate-membrane-crossing ion current trig- gered by the chemical reaction between the agent and a recognition protein con- jugated to a channel blocker. This sensor could be used in such laboratory, industri- al , or field applications as the detection of bacterial toxins in food, military chemical agents in the air, and pesticides or other contaminants in the environment. It could also be used in biological screening for hepatitis, acquired immune-deficiency syn- drome, and the like. The sensor (see figure) includes (a) a bioresponse-simulator module on which the recognition material is mounted and (b) a transducer module on which a gated membrane is affixed to a conductive meas- uring surface. A self-contained source of dc voltage and an output terminal con- nected to an alarm circuit are connected to the transducer, and a poised polarizing electrode makes contact with the blore- sponse simulator. The bioresponse simulator module con- sists of a hydrophilic film-forming layer containing, in a buffer solution of general- ly neutral pH , the recognition biomolecule for the analyte of interest. Typical examples of the recognition biomolecule might in- clude such a protein as an immunoglobu- lin-type antibody or albumin, to which a hapten, a segment of nucleic acid, or another protein segment might be attached, depending on the analyte to be detected. The recognition biomolecule is conju- gated to a channel-blocker substance, which prevents the permeation of ions through the gate membrane. Channel- blocker materials include guanidinium compounds (e.g., tetrodotoxin , saxitoxin, and neurotoxic organic derivatives such as tetramethylguanidine), divalent cations (e.g., Ca+ 2, Sr+2, Ba+2, and Cd+2), and polyvalent cations (such as La+3, Eu+3, Oy+3, and G~3. Polyvalent cations, par- ticularly the lanthanides, are the preferred cations because of their substantially greater affinities as channel blockers; ef- fective blockage is achieved at concen- trations of the order of one-thousandth those of the divalent cations. Conjugation of lanthanide ions to the protein moiety oc- curs via coordination bonding and may be NASA Tech Briefs, January 1992 performed in aqueous buffer solutions or while the cation is bound to ion channels in the gate membrane; in the latter case, the channels remain blocked. The reac- tion between the channel blocker (con- jugated to the recognition protein) and the analyte of interest at the ion-channel site in the gate membrane results in the re- moval of the blocker from the ion channel and the consequent onset of ion current. Ion channels conductive to monovalent cations serve as the gate material in the gate membrane. Examples include physi- ological sodium channel proteins, acetyl- choline receptor protein , and such channel-forming antibiotics as the grami- cidins; the gramicidins are preferred because of their high conductance, stabili- ty, ease of handling, high loading capacity, and availability. Physiological membranes containing ion channels can be used di- rectly. Alternatively, ion channels can be inserted from solution phase into artificial membranes previously prepared by con- ventional Langmuir-Blodgett techniques. The gate membrane consists of a hy- drophobic material that is essentially im- permeable to ions, particularly monovalent cations. Gate membranes can be pre- Poised pared from phospholipids or from such polymerizable unsaturated organic com- pounds as diacetylenic derivatives of fat- ty acids. In the poised state, the recognition ma- terial is bound to the gate material in the membrane in such a way as to block permeation of the membrane by ions. When the sensor is exposed to a chemical or biological agent of interest, this agent reacts with the recognition material, pull- ing it away from the gate material. This, in turn, enables an ion current to flow across the membrane. The resulting surge of current is sensed at a measuring-elec- trode surface in the transducer, triggering an alarm. This work was done by George 0. Case of Resource Technologies Group, Inc., and Jennings F. Worley of West Virginia Univer- sity for Marshall Space Flight Center. For further information, Circle 1 on the TSP Request Card. Inquiries concerning rights for the com- mercial use of this invention should be ad- dressed to the Patent Counsel, Marshall Space Flight Center [see page 14}. Refer to MFS-26121. Output to Alarm Circuit Gated Membrane (Gate Material) Bloresponse-Simulator Module The Thin-Membrane Sensor functions like a biochemical switch when exposed to the substance(s) to be detected. (The individual components are exaggerated for visual clarity and are not dimensionally to scale.) 79 ~JTissue.Simulating Gel for Medical Research The nonhardening, translucent gel more nearly simulates soft human or animal tissue. Lang/ey Research Center, Hampton, Virginia A unique gel combines a number of prop- erties important for use in the simulation of soft human or animal tissue in medical re- search. Because of its thermal stability, the gel should be especially useful for the in· vestigation of hyperthermia as a treatment for cancer. lagen gels, or polyacrylimides. Hydrated gels dry out, some gels melt at the high temperatures experienced in hyperther- mia experiments, some become hosts to micro-organisms, and some are simply too expensive or difficult to make. The new formulation overcomes most of these def~ ciencies. A number of formulas exist for produc· ing tissue-simulating gels. Many of these are based on agars, simple hydrated col· The new gel differs in that it includes a substantial percentage of ethylene glycol Bruce Coleman photo 80 He's one of the most formidable natural combat systems in existence, and we can tell you exactly how many force- pounds he'll exert at the point of impact. NTS can also simulate shock with some of the world's most sophisticated dynamic test equipment: 45,000 force-lb. to 200 g's; 25,000 g's pyroshock; hydroshock to 30 g's, 30 ms. Other capabilities include acoustic levels to 170 dB, acceleration of 800 g's/250 lb., thermal vacuum to 10-- torr, static loads exceeding 100,000 lbs, EMIIRFI of 200 VIm to 40 GHz, fast cookoff, environmental chambers for any environ- ment conceivable, and a full range of engineering services that include FMEA, fine grid and stick model FEA, and mathe- matical behavior analysis. For testing that really packs a punch, call or write NTS. National Technical Systems Engineers and technicians: Employment opportunities are a"ailable 20988 Golden Triangle Road Saugus, CA 91350 West (805) 259-8184 East (508) 263-2933 Circle Reader Action No. 404 in the solution. The first step in preparing the material is to dissolve sodium or potas- sium chloride in distilled water to attain the desired dielectric constant. A 300-bloom gelatin is then stirred into the solution in the proportions of 10 g per 100 mL of the final quantity. The resulting slurry is set aside at room temperature for several hours, with occasional stirring. The mixture is then heated slowly to 140 to 150 OF (60 to 66 "C) with constant stirring. It is kept in this state until all of the gelatin is dissolved. The ethylene glycol is then add- ed and stirred to form the final solution. It is then removed from the heat and deaerated. The mixture can be stored at this time. The mixture solidifies, but can be remelt- ed when needed. When a tissue phantom is required, the material is melted and catalj'6ed. Formaldehyde is added in the ratio of 10 mL per 100 mL of solution. The solution must be mixed thoroughly and poured into the mold quickly. The working life is less than 10 minutes. After cross-link- ing has taken place, the gel will no longer melt and can be removed from the mold. The gel can be modified to be softer or harder by altering the proportions of the in- gredients. Fillers can be added to change the electrical, mechanical, heat-conduct- ing, or sound-conducting/scattering prop- erties. In this manner, different types of tis- sues can be simulated. The gel does not support the growth of micro-organisms, and it neither hardens nor dries. A polyure- thane skin can be sprayed on the gel to provide resistance to abrasion if desired. The gel can be molded to any desired shape and has sufficient mechanical strength to maintain that shape without a supporting shell. In the absence of a shell, the ultrasonic transmissive characteristics are only those of the gel itself, thus simplify- ing the analysiS of experimental results. The gel is rubbery, so that hypodermic needles or catheters can be inserted as in- to flesh. Substances can be injected as into real tissue. In addition, because the gel is reasonably transparent, it is possible to in- spect the interior visually. This work was done by John A. Companion of Planning Research Corp. for Langley Research Center. For further in- formation, Circle 16 on the TSP Request Card. Inquiries concerning rights for the com- mercial use of this invention should be ad- dressed to the Patent Counsel, Langley Research Center [see page 14]. Refer to LAR-14036 NASA Tech Briefs, January 1992 A ABERRATION Ruling blazed, aberration- corrected diffraction gratings Oct page 97 GSC-13240 ACCELERATION TOLERANCE Effect of bed rest on tolerance 10 acceleration Mar page 68 ARC-12400 ACCUMULATORS (COMPUTERS) Digital accumulators in phase- and frequency- tracking loops Aug page 30 NPO-17909 Sign-and-magnitude up! down counter Oct page 24 NPO-I7760 ACETATES Manufacturing ethyl acetate from fermentation ethanol Sep page 84 N PO-17923 ACOUSTIC LEVITATION Reducing thermal conduction in acoustic levitators Jun page 120 NPO-17620 Acoustic levitator with furnace and laser heating Oct page 95 NPO-18035 ACOUSTIC MEASURE- MENT New sensors for flow velocity and acoustics Dec page 76 ARC-12577 ACOUSTO-OPTICS Three-dimensional acousto- optical spectrum analyzer Sep page 62 NPO-18122 Two-dimensional acousto- optical spectrum analyzer Sep page 72 NPO-18092 ACRYLATES Fast-acting rubber-to- coated-aluminum adhesive May page 44 MFS-28434 ADA (PROGRAMMING LANGUAGE) General-purpose Ada software packages Feb page 51 NPO-17983 Ada namelist package May page 50 NPO-17984 ADAPTtVE CONTROL Experiments in adaptive control of a flexible structure Feb page 31 NPO-17846 Adaptive conlrol of la'ge vibrating, rotating structures Sep page 90 NPO-17471 ADDITION RESINS Tough, high-performance, thermoplastic addition polymers May page 46 LAR-l0000 ADHESION Measuring adhesion and friction forces Jan page 39 LEW-14903 Subjecllndex of 8111 aa 1 Briefs The following pages contain a cross-referenced index of all technical briefs published in NASA Tech Briefs during 1991 (Volume 15). You can receive copies of these briefs and their accompanying Technical Support Packages (TSPs) by contacting NASA's Center for AeroSpace Information (see page 14). ADHESION TESTS Gril blasting scribes coats for tests of adhesion Jul page 84 MFS-28452 ADHESIVES Fast-acting rubber-to- coated·aluminum adhesive May page 44 MFS-28434 New polyimide has many uses Sep page 85 LAR-14163 Pressure roller for tape-lift tests Sep page 105 GSC-13230 ADSORBENTS Adsorbent removes traces of oxygen Apr page 67 NPO-17947 AERODYNAMIC BALANCE Effects of molecular processes on trim angles Apr page 62 ARC-12566 AERODYNAMIC HEAT TRANSFER Computed hypersonic flow abeut a sharp cone Ocl page 85 ARC-12675 AERODYNAMICS Computing the dynamics of helicopters Feb page 46 ARC-12337 Computing linear mathematical models of aircraft Mar page 45 ARC-12422 Aerodynamics of missiles: present and future Oct page 83 ARC-12188 Computed flow abeut the integrated space shuttle Oct page 80 ARC-12685 Numerical aerodynamic simulation program Oct page 80 ARC-12245 Experiments to verify computed flows Nov page 80 ARC-12231 AEROELASTICITY Calculating flow through a helicopter rotor May page 55 ARC-12202 Calculation of aeroelastic transients using Euler equations May page 51 ARC-12351 Transonic aeroelastlcity analysis for helicopter rotor blade Jun page 60 ARC-12550 Placing control surfaces to suppress aeroelastic fluner Jul page 71 ARC-12411 Frequency-domain identification of aeroelastic modes Dec page 73 ARC-12407 AEROSPACE PLANES Simulating the performance of a scramjet Mar page 42 ARC-12338 Computational fluid dynamics in aerospace Apr page 86 ARC-12107 AEROTHERMO-DYNAMICS Overview of aerothermo- dynamics of hypersonic flight Jul page 51 ARC-12217 AIR Real-gas properties of air and air-plus-hydrogen mixtures Jan page 30 ARC-12275 Algorithm computes hypersonic flow of air Sep page 76 ARC-12623 AIR SAMPLING Collectors or airberne and spaceborne particles Sep page 74 NPO-18183 AIR TO AIR MISSILES Computing the no-escape envelope of a short-range missile Jul page 71 ARC-12404 AIR TRAFFIC CONTROL Simulation test of descent advisor Jul page 36 ARC-1 2626 AIRBORNE LASERS Airborne laser polarization sensor Feb page 34 GSC-13314 AIRBORNEISPACEBORNE COMPUTERS Versatile, fast computer core Sep page 50 GSC-13384 AIRCRAFT CONTROL Precise autohover control for a helicopter Oct page 36 ARC-12243 AIRCRAFT LANDING Back azimuth guidance in departures and missed approaches Jul page 39 ARC-12611 AIRCRAFT SPIN Selectable-towline spin- chute system Nov page 84 LAR-14322 AIRFOILS Leading-edge pop-up spoiler for airfoil Mar page 52 LAR-13781 Composite-material airflow vane Sep page 108 LAR-14192 Flutter spoilers Sep page 93 LAR-14117 Pneumatic spoiler controls aircraHliH Nov page 71 ARC-11519 ALGEBRA Spatial-operator algebra for robetic manipulators Aug page 88 N PO-17770 ALGORITHMS Recursive inversion by finite-impulse-response filters Jan page 51 ARC-12247 Algorithm for solution of subset-regression problems Feb page 66 ARC-12145 Conjugate gradient algorithms for manipulator simulation Apr page 84 NPO-17929 Mode-switching algorithms for antenna servocontroller Sep page 56 NPO-17489 Estimating SAR Doppler shiHs from homogeneous targets Oct page 102 NPO-17869 Estimating SAR Doppler shifts from quasi- homogeneous targets Oct page 105 NPO-17905 Relative-error-covarlance algorithms Oct page 112 NPO-17956 Algorithm derives rules from data Nov page 96 NPO-18114 Removing ambiguities in remotely sensed winds Nov page 99 NPO-18079 LIGHT MEASUREMENT SYSTEMS UV CURING S RAOIOMEi ER APPLICATIONS • UNDERWATER/ ENVIRONMENTAL • LASER POWER • PHOTOMETRY • PHOTORESIST • PHOTOTHERAPY • RADIOMETRY • TRANSMISSION REFLECTANCE • UV CURING • UV HAZARDS ~ international light INC_ 17 GRAF ROAD NEWBURYPORT, MA 01950 U_S.A. • TEL. 508-465-5923 • FAX 508-462-0759 • TELEX 94-7135 ASK FOR ALL NEW LIGHT MEASUREMENT CATALOG NASA Tech Briefs, January 1992 Circle Reader Action No. 645 81 Quiet! Listen to what they're saying! I put 8 oz. Tufoil in my wife's 1977 Mercury and didn't teU her. A week later she asked me why her car was idling faster and had more pep. I told her about the Tufoil and she was pleased. (S.S. Az) Recently while driving, my car lost oil pressure due to a defective oil plug. The service station owner stated the car's engine was saved from damage due to your fine pro- duct. Thanks! (G.R. New Jersey) You have invented a masterpiece! Your product surpasses aU my ex- pectations! (C.B. New York) One 8 oz. - $ 17.75 (ship. incl.) Two 8 oz. - 29.00 (ship. incl.) 1 Quart - 38.95 (ship. incl.) 1 Gallon - 131.00 (ship. incl.) 1-800-922-0075 ORDER TODAY ~~~--....... ,--" ...... ,--, ............... ~ Fluoramlcs, Inc. 18 Industrial Avenue Mahwah, NJ 07430 N192 My check or money order for $ __ is enclosed, Charge my cred~ card: I o Visa I o Am, Express O Master Card Card No, Exp, Date _____________ _ PhOne No, Name Address p City State ______ Zip _____ _ (N,J, residents please add 7% sales tax), I I I I I I I ---------_ ... 82 Circle Reader Action No. 364 Algorithm reveals sinusoidal component of noisy signal Dec page 86 MFS-29688 ALIGNMENT Alignment tool for inertia welding Mar page 59 MFS-29667 ALUMINUM GALLIUM ARSENIDES Alternative A1,Ga",AslGaAs transistors for neural networks Sap page 26 NP0-18t77 High--gain AI.Ga",AslGaAs transistors for neural networks Sap page 24 NPO-18101 High-power AIGaAs quantum-well lasers on Si substrates Sap page 26 N PO-17988 ALUMINUM GRAPHITE COMPOSITES Open-section composite structural elements Feb page 45 MFS-26112 AMBIENT TEMPERATURE Higher performance ambient-temperature heat pipe May page 57 MSC-21515 ANALYSIS (MA THEMAT- ICS) Analysis 01 lock detection In Costas loops Jul page 38 NPO-18102 Strain center for analysis of forces Aug page 68 N P0-17966 Software for multivariable frequency-domain analysis Sap page 87LAR-14119/22 Contamination analysis program 0c1 page 66 NPO-17982 HyperCLIPS 0c1 page 69 NPO-18087 Integrated analysis capabil~ program Dec page 54 GSC-13341 ANGLES (GEOMETRY) Device measures angle of deployment Apr page 36 GSC-13351 ANIMALS Micrograv~ experiments on animals Apr page 101 ARC-12343 ANIMATION Program generates images of solid surfaces Jan page 38 MSC-21630/49 ANTENNA ARRAYS Digital signal combiner for receiVing-antenna feed array Jun page 32 NPO-18140 Reducing cross-polarized radiation from a microstrip antenna Aug page 20 NPO-18147 ANTENNAS Fast approximate analysis of modified antenna structure Mar page 64 N PO-1790 1 Caustic singularmes of high- gain, dual-shaped reflectors Apr page 38 NPO-18046 End-loaded, cavity-backed, cross-slot antennas Sep page 30 NPO-18100 Mode-sw~ching algonthms for antenna servocontroller Sap page 56 NP0-17489 ANTIFRICTlON BEARINGS Flexure bearing reduces startup friction Nov page 72 LAR-I4348 ANTIREFLECTION COATINGS Coating solar cells by microwave plasma deposition May page 60 NPO-17035 Solar-cell cover glass would reduce reflectance loss Jul page 22 LEW-14942 APERTURES Muniaperture spectrometer Dec page 38 NPO-18011 APPLICATIONS PROGRAMS (COMPUT- ERS) Another program for generating interactive graphics Jul page 65 GSC-13276 Program for generating interactive displays Jul page 64 GSC-13275 HyperCLIPS 0c1 page 69 NP0-18087 DOS batch files as control programs Nov page 101 MSC-21570 AQUICULTURE Closed-cycle nutrient supply for hydroponics Jul page 90 MSC-21655 ARC WELDING Fast, nonspanering inert-gas welding Feb page 61 MFS-29648 Compact gasltungsten-arc welding torch Jun page 108 MFS-29668 Plasma-arc torch for welding ducts in place Jun page 118 MFS-29701 Effects of heat sinks on VPPA welds 0c1 page 99 MFS-27240 Automatic control of length of welding arc Nov page 91 MSC-21473 Jointed holder for welding electrodes Nov page 95 MFS-29739 Smaller coaxial-view welding torch Dec page 82 MFS-29744 ARCHITECTURE (COMPUTERS) Algorithmically specialized parallel architecture for robotics Feb page 22 NPO-17632 Architecture for intelligent control of robotic tasks Aug page 28 NPO-17871 Study of candidate architectures for data processor Nov page 48 MSC-21690 ARTIFICIAL GRAVITY Variable-speed instru· mented centrifuges Sap page 101 KSC-11383 ARTIFICIAL HEART VALVES Numerical simulation of flow through an artificial heart Dec page 66 ARC-12478 1991 An u I Su jecllndex ARTIFICIALINTELLI- GENCE Modular, mulblayer perceptron Mar page 31 N PO-17860 Orthogonal panerns in a binary neural network May page 72 ARC-12454 Terminal attractors In neural networks Jul page 89 NP0-1 7832 Automated scheduling via artificial intelligence Aug page 86 N PO-18209 Valve- and switch- montloring computer program Nov page 98 MSC-21720 Artificial intelligence in computational fluid dynamics Dec page 73 ARC-t 2445 Neural-network simulator Dec page 48 MSC-21638 ASSOCIATIVE PROCESS- ING (COMPUTERS) T rinary associative memory would recognize machine parts Sap page 52 NPO-17850 ASTROMETRY Aiming schedule for orbiting astrometric telescope Aug page 57 NPO-12103 ASTRONOMICAL OBSERVATORIES Digtlal control of a telescope in an airplane Aug page 29 ARC-12399 ATMOSPHERIC ATTENUATION Estimating rain anenuation in satellite communication links Dec page 48 LEW-14979 ATMOSPHERIC COMPOSITION Nitrous oxide in the antarctic stratosphere Apr page 63 ARC-12223 ATMOSPHERIC ELECTRICITY Geographical variations in measured lightning fields Sep page 78 KSC-11449 ATMOSPHERIC MODELS Global reference atmosphere model-1988 Jan page 35 MFS-28397 ATMOSPHERIC RADIATION Transformations for atmospheric-radialion calculators Jul page 42 NPO-18026 ATMOSPHERIC TURBULENCE Estimating atmospheric turbulence from flight records Jul page 45 ARC-12589 ATTENUATION Calculation of pneumatic attenuation in pressure sensors Mar page 47 ARC-12210 ATTITUDE (INCLINATION) Preventing aim at an undesired target Aug page 24 NPO-18077 Adaptive control of large vibrating, rotating structures Sap page 90 NPO-t7471 ATTITUDE INDICATORS Dig~al ptlch-and-roll monitor Sap page 66 LAR-14247 AVIATION METEOROLOGY Estimating almosphenc turbulence from flight records Jul page 45 ARC-12589 AVIONICS Electromagnetic Interference in new aircraft Aug page 32 ARC-1 2161 AVIONICS Knowledge-based flight- status mon~or Dec page 31 ARC-12712 AVOIDANCE Preventing aim at an undesired target Aug page 24 N P0-18077 AXIAL FLOW Low-leakage inlet swirl brake 0c1 page 74 MFS-29608 B BACKUPS How safe IS control software Jun page 126 ARC-12710 BALL BEARINGS Low-wear ball-bearing separator Feb page 56 MFS-29666 Bearing-cartridge damping seal Aug page 77 MFS-29657 Gradient tempering of bearing races Sap page 107 MFS-28496 Flexure bearing reduces startup friction Nov page 72 LAR-14348 Monitoring bearing vibrations for signs of damage Dec page 78 MFS-29734 BALLOONS Lightweight valve closes duct quickly Dec page 64 MFS-28511 BANDPASS FILTERS Nonlinear dynamic compensation for feedback control Nov page 47 NPO-17993 BARIUM TITANATES Photorefractive cryslal compresses dynamic range of image 0c1 page 37 N PO-18098 BATCH PROCESSING DOS batch files as control programs Nov page 101 MSC-21570 BATHING Portable water-saving shower for emergencies 0c1 page 115 MFS-28459 BEAM SPLITTERS Beam spliner for welding- torch vision system May page 67 MFS-29641 BEAMS (SUPPORTS) Temperature, thermal stress, and creep in a structure Nov page 81 ARC-12213 BEARINGS Model of bearing with hydrostatic damper Jan page 43 MFS-29654 NASA Tech Briefs, January 1992 1991 Annual Subject Index LubrICation of nonconformal contacts Feb page 57 LEW·14882 Modifications of hydrostatic' bearing computer program Apr page 89 MFS·29638 Grease inhibits stress· corrosion cracking in bearing race Aug page 58 MFS·29664 Gradient tempering of bearing races Sep page 107 MFS·26496 Servo reduces friction In flexure bearing Nov page 74 LAR·14349 Dynamic tester for rotor seals and bearings Dec page 80 MFS·28493 Monitoring bearing vibrations for signs of damage Dec page 78 MFS·29734 Monitoring engine vibrations lor spectrum of exhaust Dec page 79 MFS·29733 BED REST Effect of bed rest on tolerance to acceleration Mar page 68 ARC'12400 PhYSiology of prolonged bed rest Mar page 68 ARC·12241 BENDING Mixed·mode·bendlng delamination apparatus Aug page 73 LAR·13985 BETA PARTICLES Betavoltaics of Increased power Aug page 23 NPO·17817 BIOREACTORS Membrane bioreactor with pressure cycle Jan page 55 NPO·17974 BIPOLAR TRANSISTORS Doping to reduce base resistances of bipolar transistors May page 22 NPO·17948 BISMALEIMIDE New synthesis of high· performance bismaleimides Jul page 54 LAR·13958 BIT ERROR RATE Multlple·bit errors caused by single ions Jul page 38 NPO·18075 BLADDER Ultrasonic device monitors fullness of the bladder Sep page 115 LAR·13689 BLADE SLAP NOISE Research in helICopter noise Aug page 74 ARC·12171 BLOOD CELLS Human expertise helps computer classify images Oct page 110 MSC·21737 BLOOD PUMPS Numencal simulation of flow through an artificial heart Dec page 66 ARC·12478 BLUNT BODIES Algorithm computes hyperSOnic flow of air Sep page 76 ARC·12623 BOLOMETERS Charactenzation of electrical response of photodetector Dec page 24 GSC·13349 BOLTS Staking pliers Sep page 104 MSC·21725 Designing applicabons for fasteners Ocl page 101 LEW·15081 Lockwasher strongly resists disassembly Nov page 93 MFS·29696 BOMBS (ORDNANCE) UltraSOnic deVice would open pipe bombs Sap page 108 N PO·17951 BONDING Bonding aramid rope to metal fitting Jan page 47 MSC·21618 Eliminating unbonded edges in explosive bonding Jan page 45 LAR·14096 Fast'acting rubber·to· coated·aluminum adhesive May page 44 MFS·28434 BOOSTER ROCKET ENGINES Distributed·computer system optimizes SRB joints Aug page 24 LAR·14311 BOUNDARY LAYERS Measurements of boundary layers on a compressor blade Apr page 83 lEW·14748 BOUNDARY LAYER CONTROL Making large sucbon panels for laminar·flow control Feb page 61 lAR·13844 BOUNDARY LAYER FLOW A general·coordlnate formulation for boundary· layer flow Dec page 59 ARC·12465 BOUNDARY LAYERS Reducing waterlhull drag by injecting air inl0 grooves Dec page 59 LAR'14078 BOUNDARY LAYER TRANSITION Laminar·separatlon sensor Mar page 50 LAR·14314 liquid·crystal coats help make flows visible Aug page 65 LAR·14342 BRAIN Processing of Visual information in primate brains Mar page 67 NPO·17900 BRAKES (FOR ARRESTING MOTION) Bidirectional drive·and·brake mechanism Oct page 88 MSC·21540 BRAZING Unlform·dead·weight braZing Nov page 91 MSC·21627 BRIDGES (STRUCTURES) Adjustable support for instrument package Oct page 77 GSC·13381 BRITILENESS Push tester for laminated films Sep page 92 N PO·18063 BUFFER STORAGE Deep FIFO surge buffer May page 32 ARC·12159 BUTIJOINTS Stereoscopic video weld· seam tracker Mar page 29 MFS·26116 NASA Tech Briefs, January 1992 c Program calibrates strain guages Oplimum platinum loading In PtlSnO. CO,oXldizing catalysts Filament winding of carboni carbon structures C·141 AIRCRAFT Dec page 52 MSC·21399 Oct page 95 NPO·18163 Digital control of a telescope In an airplane CANS Jun page 56 LAR·14183 Vacuum powder injector Aug page 29 ARC·12399 Crack·free. nondistortlng can for hot Isostatic pressing Automatic rejection of mullimode laser pulses Oct page 93 lAR·14179 Dec page 24 N PO·I7777 CARRIER WAVES CALCIUM CARBONATES Impregnallng coal with calcium carbonate Oct page 98 LEW·14990 CARBON FIBER REINFORCED PLASTICS Impact damage In carboni epoxy and carbon/PEEK composites Analysis of lock detection in Costas loops Dec page 46 NPO·17696 CAPACITORS Jul page 38 NPO·18102 CALCULUS OF VARIATIONS Norms and completeness in vanational methods Ferroelectric memory capaCitors for neural networks Apr page 26 N PO· 1 7973 Apr page 72 MFS·27245 CASSEGRAIN ANTENNAS Digital Signal combiner for receiving-antenna feed array Jun page 32 NPO·18140 May page 71 NPO·18071 CALIBRATING Statistical partial calibration of polarimetric SAR imagery Feb page 40 NPO·17888 Switched·capacitor voltage multiplier Aug page 16 NP().17994 CARBON FIBERS lightweight substrates for mirrors Jan page 32 NPO·17854 CASSEGRAIN OPTICS Solar concentrator has wider cone of acceptance CARBON DIOXIDE LASERS Apr page 56 MFS·28295 Plalinumltln oxide/silica gel catalyst oxidizes CO Apr page 66 LAR·14155 Apparatus for chemically treating graphite fibers Jun page 115 LAR·13959 - 3.00 -1----- 9.80 - ~ ....... -- RADIOGRAPH Radiography is just one of the many applications possible with Kevex X-RAY's patented portable X-ray source, the PXS. 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As a result there are no high voltage cables or connectors to work around. Designed, manufactured. and sold only by Kevex X-RAY. Call or write Kevex X-RAY today for information on our complete line of portable sources including the 10 micron focal spot PXS. let/ex x·lUY P.O. Box 66860 Scotts Valley, CA 95066 408-438-5940 Circle Reader Action No. 531 83 84 Circle Reader Action No. 510 5. 5. • NEW! Mouse-driven, hierarchical block diagram editor System would keep telescope reflector segments aligned Apr page 40 NPQ-17903 CATALYSTS Platinum/lin oxide/silica gel catalyst oxidizes CO Apr page 66 LAR-14155 Optimum platinum loading in PlISnO, CO-oxidizing catalysts Jun page 56 LAR-1 4183 CATHODES Behavior of NbSe. cathode in rechargeable U cell Mar page 35 NPQ-17648 CAUSTICS (OPTICS) Caustic singularities of high- gain, dual-shaped reflectors Apr page 38 NPO-1 8046 CAVITY RESONATORS Quasl-optical mili lmeter- wavelength resonator Jun page 16 NPO-17919 Microwave levitation of small objects Sep page 109 NPO-18006 CELLS (BIOLOGY) Cloned hemoglobin genes enhance growth of cells Jan page 54 NPO-17517 CENTRAL PROCESSING UNITS Improved remapping processor for digital imagery Jul page 26 MSC-21481 Versatile, fast computer core Sep page 50 GSC-13364 Programmable mainlenance processor for XAIDS Oct page 31 ARC-12164 • Dynamic Systems Modeling -linear, nonlinear, continuous, discrete, and hybrid • SystemBuild for nonlinear systems Simulation • NEWI Extended memory support for faster simulations and larger models • NEWI Robust Control and Optimization Modules available now on PCs • Intearated 3260 Jay Street systems Inc. 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Circle Reader Action No. 567 Call for your FREE Demo Diskette 1-800-932-6284 1991 CENTRIFUGAL CASTING Casting of multilayer ceramic tapes Jun page 110 NPQ-17166 CENTRIFUGES Variable-speed instru- mented centrifuges Sep page 101 KSC-ll383 CERAMIC FIBERS Fabricabon of ceramic mats Apr page 94 NPO-17210 CERAMICS Radiographic detection of voids in SiC and SiN ceramics Jan page 34 LEW-1 4881 Making three-layer solid electrolyte/electrode sandwiches May page 67 NPQ-17078 Casting of muttilayer ceramic tapes Jun page 110 NPO-17166 High-temperature insulating gap filter Jul page 52 MSC-21644 CHALLENGER (ORBITER) Placement of O-rings in solid rocket booster Aug page 76 N PO-1 8008 CHANNEL FLOW Pressure fluctuations In simulated turbulent channel flow Oct page 80 ARC-1 2597 CHARCOAL Adsorbent removes traces of oxygen Apr page 67 NPO-17947 CHARGE COUPLED DEVICES Three-dimensional acousto- optical spectrum analyzer Sep page 62 NPO-18122 Flexible generation of array- detector timing signals Oct page 35 GSC-13345 Low-noise charge-coupled device Oct page 20 NPO-18031 Altering interline transfer in a CCD to reduce saturation Dec page 30 NPO-17935 CHEMICAL REACTORS Monatomic-oxygen reactors for materials testing and surface chemistry Jun page 48 MSC-21505 Silane-pyrolysis reactor With nonuniform heating Jun page 104 N PO-17932 CHEMICAL STERILIZA- TION Apparatus circulates sterilizing gas Oct page 116 MSC-21552 CHEMISORPTION Regenerative sorption refrigerator Mar page 51 NPO-17630 Reversible chemisorption gas-gap thermal switch Nov page 54 NPO-17568 CHOKES (RESTRICTION) Self-adjusting choke for nozzle Aug page 64 NPO-17625 CHROMATOGRAPHY Chemically layered porous solids Oct page 45 MSC-21487 x CIRCUITS Circutt for current-vs.- vo~age tests of semiconduc- tors AfX page 24 MFS-29623 Interface orcutt for printer port Jun page 26 LAR-I 3950 Thermocouple-signal- condttloning orcutt Jul page 20 MFS-29695 Digttal accumulators in phase- and frequency- tracking loops Aug page 30 NPO-17909 Circutt detects faint flashes against bright background Sep page 19 MFS-28466 Resistor extends lije of battery in docked CMOS circu it Sep page 29 NPO-1 7967 Driver circuit for high-power MOSFET's Nov page 28 LEW-15089 Automatic rejection of multimode laser pulses Dec page 24 NPO-17777 Wideband phase-locked angle modulator Dec page 36 NPO-18047 CIRCULAR WAVEGUIDES Calculating scattering at Circular-waveguide junctions Jul page 20 NPO-17288 CLOSED CYCLES High-power liquid-metal heat-transfer loop May page 35 NPO-18034 CLOSURES Quick-actuating closure and handling system Mar page 54 LAR-1 3774 CMOS Resistor extends life of battery in clocked CMOS circuit Sep page 29 NPO-I 7967 COAL Impregnating coal with calcium carbonate Dec page 46 NPO-17696 COATINGS Grit blasting scribes coats lor tests of adhesion Jul page 84 MFS-28452 CODING Multiple-symbol detection of multiple-trell is-coded MDPSK Jun page 38 NPO-I 8043 Matrix encoding for correction of errors Oct page 108 NPO- I 7834 COMBAT Computing the no-escape envelope of a short-range missile Jul page 71 ARC-12404 COMBUSTION PRODUCTS Mathematical model for deposition of soot Aug page 49 MFS-28506 COMETARY ATMO- SPHERES Effects of mu~iple ion species on plasma instabilities Jul page 50 NPO-17771 COMMAND AND CONTROL Expert script generator Oct page 70 LAR-14065 NASA Tech Briefs, January 1992 1991 Annual Subject Index COMMUNICATION Optical receiver based on luminescent light trapping Apr page 59 NPO-17916 COMMUNICATION NETWORKS Quad-port Iransceivers for a dual-CRR LAN Feb page 28 NPQ-t7541 COMMUNICATION SATELLITES Estimating rain attenuation In satellite communication links Dec page 48 LEW-14979 COMPENSATORS Improved notch IiIter for synchronous-response control Apr page 48 LAR-14173 COMPLEX SYSTEMS Human error in complex systems Apr page tOl ARC-12424 Decomposing systems into subsystems for design Ocl page 69 LAR-14210 COMPOSITE MATERIALS Impact damage in carboni epoxy and carboniPEEK composites Apr page 72 MFS-27245 Mlxed-mode-bending delamination apparatus Aug page 73 LAR-13985 Stiff, strong splice for a composite sandwich structure Aug page 84 ARC-t 1743 Crack-free, nondistorting can for hOI isostatic pressing Oct page 98 LEW-14990 Crystalline imide/arylene ether copolymers Oct page 47 LAR-14264 Imide/arylene ether copolymers Dec page 44 LAR-14159 COMPOSfTE STRUC- TURES Open-section composite structural elements Feb page 45 MFS-26112 Composite struts would damp vibrations Apr page 79 NPO-17914 Lightweight composite core for curved composite mirrors Jun page 116 NPO-17858 Damping 01 vibrations in graphite/epoxy structures Jul page 74 MFS-27228 Composite-malerial airflow vane Sep page 108 LAR-1 4192 Development of composite panels for telescope mirrors Oct page 100 NPO-17895 COMPRESSIBLE FLOW Accounting lor compressibil- ity in viscous Ilow in pipes Aug page 66 ARC-12249 COMPRESSOR BLADES Measurements of boundary layers on a compressor blade Apr page 83 LEW-14748 COMPRESSORS Concentric regenerative sorption compressor Jun page 100 NPO-17877 Sorption compressor with rotary regenerator Jun page 101 NPO-17876 COMPUTATION Library of subprograms in FORTRAN 77 Dec page 55 NPO-18120 COMPUTATIONAL FLUID DYNAMICS Faster algorithm lor computation of incompress- ible lIow Feb page 52 ARC-12370 Simulation of lIow in a turbine cascade Feb page 58 ARC-12551 Computational Iluid dynamics in aerospace Apr page 86 ARC-12107 Surface-shading program May page 49 ARC-12381 Computing flow in a labyrinth seal Jun page 98 MFS-29682 Generating three- dimensional grids about anything Jun page 58 ARC-t2620 Entrophy-based approach to nonlinear stability Jul page 76 ARC-t2435 Streamwise algorithm for simulation of flow Jul page 70 ARC-12718 Adaptive grids for computations of three- dimensional lIows Aug page 66 ARC-12479 Growth of instabilities in two types of mixing layers Aug page 75 ARC-12567 IncompreSSible, viscous lIow about an ogive/cylinder Aug page 73 ARC-11793 Computed lIow about the Integrated space shuttle Oct page 80 ARC-12685 Computed turbulent lIow In a turnaround duct Oct page 82 ARC-12552 Improved panel-method! potential-liow code Oct page 66 ARC-12642 Numerical aerodynamic simulation program Oct page 80 ARC-12245 Spectral method for simulation 01 vortex rings Oct page 74 ARC-12639 Experiments to verify computed flows Nov page 80 ARC-12231 Artificial intelligence in computational lIuld dynamics Dec page 73 ARC-12445 Computations of impulsively started viscous lIow Dec page 75 ARC-12382 COMPUTATIONAL GRIDS Semiautomatic design of zonal computational grids Feb page 52 ARC-12322 Generating three- dimensional grids about anything Jun page 58 ARC-12620 NASA Tech Briefs, January 1992 Computation of lIow in a turbine stage on a refined grid Nov page 90 ARC-12444 Generation of surface grids from data points Dec page 86 ARC-12481 COMPUTER AIDED DESIGN Modifications 01 hydrostatic- bearing computer program Apr page 89 MFS-29638 Computer-aided design of sheet-material parts Aug page 83 MFS-29759 Computer language for optimization 01 design Aug page 59 LAR-14280 Design and analysis of linear control systems Aug page 59 KSC-11376 Sollware for design of life- support systems Aug page 89 ARC-12665 Decomposing systems into subsystems for design Oct page 69 LAR-14210 Numerical-optimization program Dec page 57 LAR-14500 COMPUTER AIDED MAPPING Program computes universal transverse Mercator projection Jul page 62 NPO-18086 COMPUTER AIDED TOMOGRAPHY Computed tomography for inspection of thermistors Jun page 111 MFS-29662 Verifying x-radiographs with computed tomographs Jun page 116 MFS-29649 COMPUTER COMPO- NENTS Micro channellMultlbus-1i interface circuit Jul page 24 MSC-21506 Versatile, fast computer core Sep page 50 GSC-13364 COMPUTER GRAPHICS Program generates images of solid surfaces Jan page 38 MSC-21630/49 Surface-shading program May page 49 ARC-12381 Graphics software for VT terminals Jul page 64 MFS-27214 Software package for real· time graphics Jul page 32 ARC-12357 Graphical planning of spacecraft missions Aug page 60 GSC-13318 Integrated analysis capability program Dec page 54 GSC-13341 Sollware for depiction of three-dimensional objects Dec page 55 MSC-21708 COMPUTER NETWORKS Numerical aerodynamic simulation program Oct page 80 ARC-12245 COMPUTER PROGRAMS Estimating the cost of developing software Feb page 48 NPO 17936 Do you need support for ••• Ada? i860? 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Folsoni IIII ' ICI 526 East Bidwell Street Folsom, CA 95630 tel: 916983.1500 fax : 916.983.7236 86 Circle Reader Action No. 5 13 How safe is control software Jun page 126 ARC-12710 COMPUTER STORAGE DEVICES Deep FIFO surge buffer May page 32 ARC-12159 COMPUTER SYSTEMS PERFORMANCE Characterizing computers and predicting compuling times Sap page 60 ARC-12434 COMPUTERIZED SIMULATION Displaying computer simulations of physical phenomena Feb page 32 ARC-12502 Computing rotational! vibrational dynamics of turbine engines Mar page 42 LEW-1 4770 Simulating the perlormance of a scramjet Mar page 42 ARC-12338 Simulating dynamics of the Gamma·Ray Observatory satellite Apr page 76 GSC-13293 High'resolution numerical simulation of shock waves Jul page 74 ARC-11730 Program for parallel discrete-event simulation Nov page 69 NPO-18037 Aid for simulating digital flight control systems Dec page 56 ARC-11710/1 Neural-network simulator Dec page 48 MSC-21638 Software for simulation of development of software Dec page 56 NPO·18295 CONCURRENT PROCESSING Program for parallel discrete~event simulation Nov page 69 NPO-18037 CONDUCTORS Testing conductive films lor continuity Feb page 41 N PO-17938 Electrochemical deposition of conductive polymers Apr page 64 NPO-17826 Intramuscular contact lead filled with conductive solution May page 74 NPO-17186 CONFIDENCE Estimating confidence in data via trend analysis Mar page 63 MFS-29710 CONFIDENCE LIMITS Computing confidence limits Mar page 46 MFS-29476 Developing confidence limits for reliability of software Nov page 102 LAR-14292 CONJUGATE GRADIENT METHOD Conjugate gradient algorithms for manipulator simulation Apr page 84 NPO-17929 CONNECTORS Quick-connect truss lastener Jul page 84 MSC-21504 Quick-connecVdisconnect joint for truss structures Sap page 102 MSC·21539 CONSTRAINTS Solving constraint- satrsfaction problems in prolog language Nov page 101 ARC-12460 CONTACT RESISTANCE Flange correctIon for metal- to-metal contacts May page 20 NPO-18052 CONTAINERLESS MELTS Reducing thermal conduction in acoustic levijators Jun page 120 NPO-17620 Experiments on rotating, charged liquid drops Jul page 49 NPO-17893 Acoustic levitator wijh furnace and laser heating Oct page 95 NPO-I6035 CONTAMINATION Pressure roller for tape-lift tests Sap page 105 GSC-13230 Contamination analysis program Oct page 66 NPO-17982 CONTOUR SENSORS Contact probe with pivoting tip Nov page 77 MFS-28536 CONTRAST Photorefractive crystal compresses dynamic range of image Oct page 37 NPO-18098 CONTROL Docking system with video feedback Mar page 31 MFS-28421 Active compliance and damping in telemanipulator control Apr page 48 N PO-17969 How safe is control software Jun page 126 ARC-12710 Design and analYSIS of linear control systems Aug page 59 KSC-11376 Research on controls and displays for V/STOL airplanes Sep page 68 ARC-12215 Analyzing control!structure interactions Oct page 67 LEW-14904 CONTROL EQUIPMENT Preventing aim at an undesired target Aug page 24 NPO-18077 Robot grasps rotating object Sep page 58 NPO-18016 Software for supervisory and shared control of a robot Oct page 102 NPO-18116 CONTROL SURFACES Placing control surlaces to suppress aeroelastic flutter Jul page 71 ARC-12411 CONTROLLERS Compact force-reflecting hand controller Apr page 88 NPO-17851 CONTROL SURFACES Leading-edge pop·up spoiler for airloil Mar page 52 LAR-13781 CONTROL THEORY State-variable representa' tions for moving-average sampling Jan page 48 MFS-28405 1991 Annual Subject Index CONTROL UNITS(COMPUTERS) ArcMecture for intelligent control of robotic tasks Aug page 28 NPO-17871 Controlling laboratory processes from a personal computer Sap page 88 LEW-14907 CONTROLLERS Closed-loop chopping-mirror controller Sap page 50 ARC-III77 CONVERGENT- DIVERGENT NOZZLES Two·phase Hero turbine wijh curved nozzles Nov page 87 NPO-18059 COOLING Stirling-cycle cooling for tunable diode laser Aug page 16 NPO-18045 Transpiration cooling of hypersonic blunt body Aug page 57 ARC-12383 Vaporization would cool primary battery Sep page 90 NPO-17805 COOLING SYSTEMS Garment would provide variable cooling Jul page 44 MSC-21531 COPOLYMERS Crystalline imide/arylene ether copolymers Oct page 47 LAR-14264 Imide/arylene ether copolymers Dec page 44 LAR-14159 COPPER Forming YBa"Cu,o, .. , superconductors on copper substrates Mar page 38 KSC-11448 CORNEA Two-wavelength interlerometric keratometer Feb page 39 NPO-17537 Computer-driven keratometer Sap page 118 NPO-17079 COROSION PREVENTION Grease inhibits stress- corrosion cracking in bearing race Aug page 58 MFS-29664 COST ESTIMATES Estimating the cost of developing software Feb page 48 NPO-17936 COUNTING Vacuum chuck holds filter pad for counting particles Apr page 52 MFS-28420 COUNTING CIRCUITS Sign· and-magnitude upl down counter Oct page 24 N PO·I7760 COUPLINGS Rotary coupling extends Ide of hose Mar page 49 GSC-13316 Heat-transfer coupling for heat pipes Sap page 92 NPO-17863 COVARIANCE Generalized covariance analysis for remote estimates Jan page 52 N PO-17824 Relative-errar-covariance algorilhms Oct page 1 t 2 NPO-17956 CRACK PROPAGATION Fatigue-crack-growth computer program Apr page 74 MSC-21669 CRACKING (FRACTURING) Grease inhibits stress- corrosion cracking in bearing race Aug page 58 MFS-29664 CREEP ANALYSIS Temperature, thermal stress, and creep in a structure Nov page 81 ARC-12213 CREW PROCEDURES (IN FLIGHT) Flight checklists and interruptions Mar page 68 ARC-12~24 CRYOGENIC EQUIPMENT Low-wear ball-bearing separator Feb page 56 MFS-29666 CRYOGENIC FLUIDS Improved ultrasonic transducer for measuring cryogenic lIow Nov page 78 MFS-29687 CRYOGENICS Mechanically oriented, low- Curie-temperature materials Apr page 71 MFS-26110 Mixed·gas sorption Joule- Thomson refrigerator May page 38 NPO-17569 Concentric regenerative sorption compressor Jun page 100 NPO-I7877 Perlormance of superconducting-cavity maser Jun page 30 NPO-18175 Test adapter for infrared detectors Jul page 73 ARC-11389 Improved gas-gap heat switch Aug page 49 NPO-18136 CRYSTAL GROWTH Modified furnace makes more silicon ribbon Feb page 64 NPO·17350 Electroslatic stabilization of growing protein crystals Mar page 35 NPO-I7747 Improved boat for liquid- phase epitaxy Jul page 80 LAR-14199 Integrated protein-crystal- growing apparatus Jul page 90 MFS-28422 Thermosyphon suspension for growth of crystals Jul page 82 MFS-26113 Compact apparatus for growth of protein crystals Aug page 51 MFS-28507 Initiating growth of crystals away Irom container walls Sep page 106 MFS-28473 CRYSTALLINITY Correlating DSC and x-ray measurements of crystallinity Sep page 77 NPO-1 7958 CURIE TEMPERATURE Mechanically oriented, low- Curie-temperature materials Apr page 71 MFS-26110 NASA Tech Briefs, January 1992 1991 Annual Subject Index CUSHIONS Thermal slrap and cushion for thermoetectric cooler Jun page 16 NPO-17806 CYBERNETICS Orthogonal patterns In a binary neural network May page 72 ARC-12454 D DAMPERS (VALVES) Model of bearing with hydrostatic damper Jan page 43 MFS-29654 DAMPING Bearing-cartridge damping seal Aug page 77 MFS-29657 Damping seals would help support turbopump rotor Aug page 77 MFS-27227 DATA ACQUISITION System acquires and displays signal-propagation data Sep page 64 NPO-18190 Program calibrates strain gauges Dec page 52 MSC-21399 DATA CONVERTERS Modular VLSI Reed- Solomon decoder Sep page 49 NPO-17897 DATA PROCESSING Optical backplane interconnection Feb page 20 LAR-14052 Processor reformats data for transmission in bursts Jun page 36 MSC-21727 Software package for real - time graphics Jul page 32 ARC-12357 Hidden-Markov-model analysis of telemanipulator data Oct page 87 NPO-18000 Algorithm derives ru les from data Nov page 96 NPO-1 8114 Study of candidale architectures for data processor Nov page 48 MSC-21690 DATA RECORDERS Sign-and-magnitude upl down counter Oct page 24 NPO-17760 DATA REDUCTION Dynacounter electronic data-reduction system Nov page 46 MSC-21568 DATA RETRIEVAL Systematic Identification of discrepant hardware Jun page 58 MFS-29525 Video image communication and retrieval-updated Nov page 66 NPO-18076 DATA STORAGE Deep FIFO surge buffer May page 32 ARC-121S9 DECODERS Modular VLSI Reed- Solomon decoder Sep page 49 NPO-17897 DECOMMUTATORS System decommutes and displays telemetry data Sep page 89 GSC-13324 DECONDITIONING Physiology of prolonged bed rest Mar page 68 ARC-12241 DEFECTS Reactive fluorescent dyes lor urethane coatings Oct page 44 NPO-18038 DEFLECTION Program analyzes errors in STAGS Jan page 36 LAR-14063 DELAMINATING Mixed-mode-bending delamination apparatus Aug page 73 LAR-13985 DELTA WINGS Computed hypersonic viscous flows over delta wings ' Dec page 70 ARC-12179 DEMODULATORS Resolving phase ambiguities in OOPSK Jul page 30 NPO-17853 DENSITY MEASUREMENT Laser spectroscopic measurement of temperature and density May page 43 ARC- t 2719 DEOXYGENATION Copper-exchanged zeolite L traps oxygen Sep page 86 NPO-17761 DEOXYRIBONUCLEIC ACID Environmental control of a genetic process Jan page 54 NPO-17576 DEPOSITION Coating solar cells by microwave plasma deposition May page 60 NPO-17035 Preventing chemical-vapor deposition In selected areas Jun page 122 LAR-14300 Deposition of diamond like films by ECR microwave plasma Oct page 42 N PO-18094 DESCENT Simulation test of descent advisor Jul page 36 ARC-12626 DESIGN ANALYSIS Computer language for optimization of design Aug page 59 LAR-14280 Decomposing syslems into subsystems for design Oct page 69 LAR-14210 Numerical-optimization program Dec page 57 LAR-14500 Software-design-analyzer system Dec page 57 NPO-18212 DESULFURIZING Zeol ites remove sulfur from fue ls Apr page 68 NPO-17480 Impregnating coal with calcium carbonate Dec page 46 N PO-17696 DIAMONDS Deposition of diamondlike films by ECR microwave plasma Oct page 42 NPO-1 8094 Diamond-coated wire- feeding nozzle Nov page 93 MFS-29714 NASA Tech Briefs, January 1992 DIAPHRAGMS (MECHAN- ICS) DISCONNECT DEVICES Redundant togglelhook release mechanism Research on controls and displays for V/STOL airplanes DISTRIBUTED PROCESS- ING Sep page 68 ARC-12215 System for research on multiple-arm robots Dual-diaphragm tank with leakage-indicating drain Sep page 91 MSC-21703 Nov page 71 MSC-21671 DISSIPATION Oct page 30 NPO-17971 Artificial dissipation in computation of hypersonic flows DOCUMENTATION Software-design-analyzer system DIATOMIC MOLECULES Calculating electronic spectra of diatomic molecules DISPLA Y DEVICES Another program for generating interactive graphics Jul page 65 GSC-13276 Jun page 124 ARC-12260 Dec page 57 NPO-18212 Oct page 41 ARC-12412 Helmet-mounted liquid- Extrema principles of DIESEL FUELS cryslal display dissipation in fluids Zeolites remove sulfur from Jul page 34 MSC-21460 Jul page 48 ARC-12318 fuels DOPPLER EFFECT Behavior of Costas loop In reception of telemetry Aug page 30 NPO-18084 Apr page 68 NPO-17480 Program for generating DISTRIBUTED FEEDBACK interactive displays LASERS Estimating SAR Doppler DIFFRACTION Jul page 64 GSC-13275 Lateral-grating DFB laser shifts from homogeneous Computing performance of Mar page 22 LAR-13977 targets an optical system Effects of frame rates In Oct page 102 NPO-17869 Jul page 60 GSC-13128 video displays DISTRIBUTED PARAM- Aug page 32 ARC-12358 ETER SYSTEMS Estimating SAR Doppler DIGITAL DATA Software for multivariable shifts from quasi- Processor reformats data for frequency-domain analysis homogeneous targets transmission In bursts rr;;:;;;;;:;;;;;:;;;;;:;;;;;:;;;;;:;;;;;:;;;;;:;;;;;:;;;~Se~p~pa~g~e~8~7:L~A~R~-1~4~1~19~/~22~~Oc;;;;;t p~a~g~e~1~05;;;;;~N~P~O;- 1~7~9;05~ Jun page 36 MSC-21727 DIGITAL SYSTEMS Electromagnetic interference in new aircraft Aug page 32 ARC-12161 Programmable maintenance processor for XAIDS Oct page 31 ARC-12164 Aid for simulating digital flight control systems Dec page 56 ARC-11710/1 DIGITAL TECHNIQUES Simultaneous detection and estimation amid strong dynamical effeets Jan page 28 NPO-17820 Digital control of a telescope in an airplane Aug page 29 ARC-12399 Digital image veloclmetry Oct page 78 ARC-12774 Matrix encoding for correction of errors Oct page 1 08 N PO-17834 DIODES Low-loss coupler for microwave laser·diode modulation Apr page 22 LAR-13788 Multiple integrated in-line diode lasers Nov page 34 LAR-14378 DIRECT CURRENT Rugged direct-current transducer Dec page 28 N PO-1795 7 DIRECTIONAL SOLIDIFI- CATION (CRYSTALS) Controlled temperature gradient improves freezing alloy Sep page 83 MFS 28314 XYZMAP Full 3-D DiiUtizing and Mapping System • Provides Forward and Reverse Zoom Functions • Supports Scanner and Digitizer Input Devices • Displays Quadrangle or Point and Radius Fonnats • Includes XYZSP ACE Spatial Database Engine XYZSPACE Multi-dimensional Spatial Database Engine • Pennits Up to 30 Dimensions or Variables • Cellular Multiresolution Capability • Provides Natural Clustering of Infonnation • Address Radius. 50.000 KM by 10 Micron Precision Available Platfonns: 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Video Products Division PULNiX America, Inc. 770 Lucerne Drive Sunnyvale, CA. 94086 Tel: 408-733-1560 Fax: 408-737-2966 Circle Reader Action No. 416 1991 Annual Subject Index DOPPLER RADAR Low·speed optical speedometer Jun page 54 NPO- t 7702 Ambiguity of Doppler centroid in synthetic- aperture radar Nov page 48 NPO-17943 DRAG Crescent wing planforms reduce lift-dependent drag Apr page 79 LAR-14015 DRAG REDUCTION Polymers and riblets reduce hydrodynamic skin friction Oct page 77 LAR-14271 Reducing waterlhull drag by injecting air into grooves Dec page 59 LAR-14078 DRILLS Hand broaching tool for use in confined areas Jun page 123 MFS-29669 DROPS (LIQUIDS) Experiments on rotating charged liquid drops Jul page 49 NPO-17893 Vapor-screen-density controller Nov page 38 LAR-14099 DUCTS Algebraic model of turbulence for internal flow Aug page 63 ARC-12544 Computed turbulent flow in a turnaround dl 'ct Oct page 82 ARC-12552 Lightweight valve closes duct quickly Dec page 64 MSF-28511 DYNAMIC CHARACTERIS- TICS Simulating dynamics of the Gamma-Ray Observatory satellite Apr page 76 GSC-13293 DYNAMIC LOADS Improved computation of dynamic stresses Jan page 39 MFS-29745 Calculating dynamics of helicopters and slung loads Aug page 71 ARC-12755 DYNAMIC STRUCTURAL ANALYSIS Dynamic analyses including joints of truss structures Dec page 62 LAR-1 4306 DYNAMICAL SYSTEMS Terminal attractors in neural networks Jul page 89 N PO-17832 E EARTH GRAVITATION Computing gravitational bumps from repeating-orb~ data May page 52 NPO·17925 EARTH OBSERVING SYSTEM (EOS) Spaceborne microwave imagers Dec page 42 N PO-17094 EARTH RESOURCES SURVEY AIRCRAFT Measuring wildfires from aircraft and satellites Feb page 40 ARC-12132 EDDY CURRENT Detecting filler spaces under tiles May page 61 KSC-11411 EDDY CURRENTS Noncontact measurements of torques In shafts Mar page 50 MFS-29717 EDGES Llquid-crystaJ light valve enhances edges in images Apr page 54 NPQ-I7768 EDUCATION Displaying computer simulations of physical phenomena Feb page 32 ARC·12502 ELASTIC PROPERTIES Triangular element for analyzing elasticity of laminates Jul page 68 ARC-12534 ELASTIC WAVES Software models Impact stresses Nov page 65 MFS-29628 ELASTOHYDRODYNAMICS Lubrication of nonconformal contacts Feb page 57 LEW-14882 ELASTOPLASTICITY Program for elastoplastic analyses of plane frames Aug page 59 LEW·14889 ELECTRIC BATIERIES Reinforced positive filler paste for lead/acid batteries Jan page 20 NPO-16991 Lightweight, high-energy lead/acid battery Apr page 22 NPO-16962 Betavoftaics of increased power Aug page 23 NPO-17817 Vaporization would cool primary battery Sep page 90 NPO-17805 ELECTRIC BRIDGES Thermocouple-signal- conditioning circuit Jul page 20 MFS-29695 ELECTRIC CONNECTORS Sealing out-of-round tubes with O-rings Sep page 1 04 N PO-I7791 ELECTRIC CONTACTS Formation of ohmic contacts on epitaxial GaAs Mar page 58 NPO-I7795 Flange correction for metal- to-metal contacts May page 20 NPO-18052 Intramuscular contact lead filled with conductive solution May page 74 NPO-17186 ELECTRIC DISCHARGES Electrical-discharge machining with additional axis Feb page 63 MFS-29630 ELECTRIC FIELDS Geographical variations in measured lightning fields Sep page 78 KSC-11449 ELECTRIC MOTORS Pulse-width-modulating driver for brushless de motor Sep page 18 NPO-17142 ELECTRIC WELDING Magnetic deflection of welding electron beam Apr page 94 MFS-29659 Tool for robotic resistive roll welding May page 62 MFS-29660 NASA Tech Briefs, January 1992 1991 Annual Subject Index Compact pinch welder Jun page 109 MFS-29670 Spot-welding gun is easy to use Jun page 119 MFS-29693 Monitoring welding images and data simultaneously Aug page 29 MFS-29772 ELECTRICAL MEASURE- MENT Cross-qui nt-bridge resistor Jun page 28 NPO-18106 ELECTRtCAL RESIS- TANCE Effects of moisture on zinc orthotitanate paint Mar page 41 NPO-17742 ELECTRICAL RESISTIVITY Measuring electrical resistivity of compacted powder Nov page 58 NPO-1 8056 ELECTROCHEMICAL CELLS Behavior of NbSe, cathode in rechargeable Li cell Mar page 35 NPO-17648 ELECTRODES Lightweight fibrous Ni electrodes for Ni/H, batteries Jul page 56 LEW-14955 Jointed holder for welding electrodes Nov page 95 MFS-29739 ELECTROLYSIS Ionizable-substance detector Dec page 38 MFS-28515 ELECTROLYTES Ltlhium cells accept hundreds of recharges Jun page 28 NPO-17676 ELECTROLYTIC CELLS Making three-layer solid electrolyte/electrode sandwiches May page 67 NPO-17078 Stacking oxygen-separation cells Jun page 118 N PO-17223 ELECTROMAGNETIC ABSORPTION Optical receiver based on luminescent light trapping Apr page 59 NPO-17916 Script-factor modeling of absorption in a solar receiver Dec page 40 NPO-18018 ELECTROMAGNETIC INTERFERENCE Electromagnetic interference in new aircraft Aug page 32 ARC-12t61 ELECTROMAGNETIC PROPULSION Electromagnetic gun with commutated coils Apr page 26 N PO-17839 ELECTROMAGNETIC PUMPS TEM pump with external heat source and sink Jul page 79 NPO-17864 ELECTROMIGRATION Designing accelerated tests of electromigratlon Aug page 54 NPO-18012 Five-segment interconnec- tion for electromigration tests Aug page 18 NPO-18105 ELECTRON BEAM WELDING Magnelic deflection of welding electron beam Apr page 94 MFS-29659 ELECTRONIC SPECTRA Calculating electronic spectra of diatomic molecules Oct page 41 ARC-12412 ELECTRO-OPTICS Eleclro-optical position- measuring system Jan page 26 LAR-13840 ENDOSCOPES Lighted, folding inspection mirror Oct page 92 MFS-28457 ENERGY ABSORPTION Docking system would accommodate misalignments Aug page 68 MSC-21 596 ENERGY DISSIPATION Exterma principles of dissipation in fluids Jul page 48 ARC-12318 ENGINE ANALYZERS Monitoring engine vibrations for spectrum of exhaust Dec page 79 MSF-29733 ENGINEERING MANAGEMENT Tracing and control of engineering requirements Dec page 56 NPO-18215 ENVtRONMENTAL CONTROL Environmental control of a genetic process Jan page 54 NPO-17576 ENVIRONMENT POLLUTION Removing spilled oil with liquid nitrogen Mar page 38 LAR-1 4227 EPITAXY Improved boat for liquid phase epitaxy Jul page 80 LAR-1 4199 EQUA n ONS OF MOTION Efficient computation of inertia matrix of a manipulator May page 70 N PO-17545 EQUATIONS OF STATE Calculating thermophysical properties of 12 fluids Dec page 52 MSC-21664 ERROR ANALYSIS Designing accelerated tests of electromigratlon Aug page 54 NPO-1 8012 ERROR CORRECTING CODES Matrix encoding for correction of errors Oct page 108 NPO-17834 ERROR CORRECTING DEVICES Self-testing static random- access memory Feb page 30 NPO-17939 ERRORS Relative-error-covariance algorithms Oct page 112 NPO-17956 ESnMATING Estimating liquid and gas contents In a tank May page 51 MSC-21500 NASA Tech Briefs, January 1992 ETCHING Rapid dry etching of photoreslsts without toxic gases Jun page 104 ARC-11873 ETHYL ALCOHOL Manufacturing ethyl acetate from fermentation ethanol Sep page 84 NPO-17923 ETHYLENE OXIDE Apparatus circulates sterilizing gas Oct page 116 MSC-21552 EULER EQUATIONS OF MOn ON Using multiple grids to compute flows Mar page 37 ARC-12321 Calculation of aeroelastic transients using Euler equations May page 51 ARC-12351 EVALUATION Characterizing computers and predicting computing times Sep page 60 ARC-12434 Human expertise helps computer classify images Oct page 110 MSC-21 737 EVAPORATIVE COOLfNG Vaporization would cool primary battery Sep page 90 NPO-17805 EXPERT SYSTEMS Parallel inferencing for rule- based expert systems Mar page 62 NPO-18004 Software for design of life- support systems Aug page 89 ARC-12665 Expert system for heat exchanger Oct page 90 NPO-17991 Intelligent computerized training system Oct page 107 MSC-21381 EXPLOSIVE DEVICES Apparatus for tests of percussion primers Jan page 42 LAR-13996 EXPLOSIVE FORMING Particle-In-cell simulation of explosive flow Oct page 84 ARC-12543 EXPLOSIVE WELDING Eliminating unbonded edges in explosive bonding Jan page 45 LAR-14096 EXTRAVEHICULAR ACTIVITY Software for integration of EVA and telerobotics Oct page 69 N PO-18220 EXTREME ULTRAVIOLET RADIATION Compact x-ray and extreme- ultraviolet monochromator Jun page 44 MFS-28499 Four-mirror x-ray and extreme-ultraviolet monochromator Jun page 44 MFS-28498 Scanning x-ray or extreme- ultraviolet monochromator Aug page 52 MFS-28492 Ultra-high-spectral- resolution x-ray/EUV monochromator Sep page 70 MFS-28500 EYE (ANATOMY) Two-wavelength interferometric keratometer Feb page 39 NPO-17537 Computer-driven keratometer Sep page 11 8 NPO-17079 Compensating for movement of eye in laser system Nov page 46 MSC-21509 EYE DISEASES Portable video/digital retinal funduscope Sep page 115 MSC-21675 EYE MOVEMENTS Instrument measures ocular counterrolling Dec page 91 MSC-21711 F F-16 AIRCRAFT Transonic flows about a fighter airplane Oct page 79 ARC-12304 Navler-Stokes computations on zonal grids Dec page 71 ARC-12447 FABRICATION Fabrication of ceramic mats Apr page 94 NPO-I7210 Salt filler for making covered channels Sep page 103 MFS-29729 FACTORIZATION QR factorization in the partial-realization problem Apr page 98 ARC-12284 FAILURE ANALYSIS Probabllisticifracture- mechanics model for service life Jul page 77 MFS-27237 FAR INFRARED RADIATION Phototransistors for long- wavelength infrared May page 26 NPO-18029 Hole-impeded-doping- superlattice LWIR detectors Sep page 22 NPO-17880 FARADAY EFFECT Optical isolators with transverse magnet Feb page 36 LAR-14092 FASTENERS Lightweight memory-metal pin puller Jul page 69 NPO-18131 Push-to-Iock, push-to- release mechanism Jul page 73 MSC-21520 Quick-connect truss fastener Jul page 84 MSC-21504 Designing applications for fasteners Oct page 101 LEW-15081 Lockwasher strongly resists disassembly Nov page 93 M FS-29696 FATIGUE LIFE Controlled temperature gradient improves freez ing alloy Sep page 83 MFS-28314 FATIGUE (MATERIALS) Fatigue-crack-growth computer program Apr page 74 MSC-21669 Repairing a shaft prone to fatigue Oct page 94 MFS-28518 Alloy has high fatigue strength in hydrogen Nov page 62 MFS-28464 Dynacounter electronic data-reduction system Nov page 46 MSC-21568 FATIGUE TESTS Mode-Ii-fracture specimen and holder Apr page 80 LEW-14964 FAULT TOLERANCE Programs for modeling fault- tolerant computing systems Jan page 37 LAR-14165 FEEDBACK Microwave oscillator would have reduced phase noise Jun page 20 N PO-17945 Digital phase-locked loop with phase and frequency feedback Nov page 36 N PO-I7722 FEEDBACK CONTROL Docking system with video feedback Mar page 31 MFS-28421 AnthropomorphiC remote manipulator Apr page 92 NPO-17975 More about video-feedback docking system Oct page 36 MFS-28419 R-parameterization of linear feedback systems Oct page 1 06 ARC-1 2369 Nonlinear dynamic compensation for feedback control Nov page 47 NPO-17993 FEEDING (SUPPLYING) Diamond-coated wire- feeding nozzle Nov page 93 MFS-29714 FERMENTATtON Membrane bioreactor with pressure cycle Jan page 55 NPO-17974 Manufacturing ethyl acetate from fermentation ethanol Sep page 84 N PO-17923 FERROCENES Organometallic salts generate optical second harmonics Jun page 54 NPO-I7730 FERROELECTRICITY Ferroelectric memory capacitors for neural networks Apr page 26 NPO-17973 fiBER COMPOSITE!! Farley three-dimensional- braiding machine Mar page 60 LAR-13911 Filament winding of carboni carbon structures Oct page 95 NPO-18163 FIBER OPTICS Diplex fiber-optic link for frequency and time Signals Jun page 39 NPO-1 8180 FIBERS Making mullite fibers by airgap wet spinning May page 60 MFS-28431 Apparatus for chemically treating graphite fibers Jun page 115 LAR-13959 Superfiber for strong. light labrlcs Sep page 80 MSC-21659 Effects of Interference on scattering by parallel fibers Nov page 60 ARC-12530 FIELD EFFECT TRANSISTORS Dc-to-dc converter uses reverse conduction of MOSFETs Mar page 22 LEW-14944 Stacked-gate FET's for analog memory elements Jul page 16 NPO-17627 Driver circuit for high-power MOSFET'S Nov page 28 LEW-15089 FILAMENT WINDtNG Filament winding of carboni carbon structures Oct page 95 NPO-18163 FILLERS High-temperature insulating gap filler Jul page 52 MSC-21644 Salt filler for making covered channels Sep page 103 MFS-29729 FINITE DIFFERENCE THEORY Direct finite-difference simulators of turbulent flow Dec page 76 ARC-12463 FINITE ELEMENT METHOD Program analyzes errors in STAGS Jan page 36 LAR-14063 Analyzing large reflector antenna structures Apr page 77 NPO-I7783 Calculating transient vibrations of coupled substructures May page 54 MFS-28477 Stress stiffening of STAR- DYNE plate elements Jul page 69 MFS-29738 Triangular element for analyzing elasticity of laminates Jul page 68 ARC-12534 FIRE FIGHTING Self-adjusting choke for nozzle Aug page 64 N PO-17625 FIXTURES O-ring-testing fixture Feb page 54 MFS-28414 Self-aligning sensor- mounting fixture Jun page 107 MFS-29663 Test adapter for infrared detectors Jul page 73 ARC-11389 Magnetic-bearing test fixture Nov page 82 LAR-14312 FLANGES Flange correction for metal- to-metal contacts May page 20 NPO-18052 FLAT CONDUCTORS Electrochemical deposition of conductive polymers Apr page 64 N PO-17826 FLEXIBLE BODIES Experiments in adaptive control of a flexible structure Feb page 31 NPO-17846 Analyzing controVstructure interactions Oct page 67 LEW-14904 89 FLEXIBLE SPACECRAFT Zero-spring-rate mechanism/air suspension cart Aug page 69 LAR-14142 FLIGHT CHARACTERIS- TICS Computing the dynamics of helicopters Feb page 46 ARC- I 2337 Computing linear mathemalical models of aircraft Mar page 45 ARC-12422 Surface-shading program May page 49 ARC-12381 Software package for real- time graphics Jul page 32 ARC-12357 FLIGHT CONTROL Aid for simulal ing digilal flight control systems Dec page 56 ARC-I 1710/1 FLIGHT ENVELOPES Computing the no-escape envelope of a short-range missile Jul page 71 ARC-12404 FLIGHT MANAGEMENT SYSTEMS Knowledge-based flight- status-monitor Dec page 31 ARC-12712 FLIGHT OPERATIONS Flight checklists and interruptions Mar page 68 ARC- I 2324 FLIGHT PATHS Simulation test of descent advisor Jul page 36 ARC-12626 FLIGHT SAFETY Estimating atmospheric turbulence from flight records Jul page 45 ARC-12589 FLIGHT SIMULATION Computer simulation of a small turboshaft engine Mar page 55 ARC-12299 FLIGHT STRESS (BIOLOGY) More life-science experiments for Spacelab Apr page I 02 ARC-I 23 16 FLOW DISTRIBUTION Streamwise algorithm for simulation of flow Jul page 70 ARC-12718 Helicity-density and normalized-helicity maps of !lows Aug page 62 ARC-12464 Improved panel-method! potenlial-flow code Oct page 66 ARC-12642 FLOW EQUATIONS Using mulltiple grids to compute !lows Mar page 37 ARC-12321 Artificial dissipation in computalion of hypersonic flows Jun page 124 ARC-12260 Enlrophy-based approach to nonlinear stabil ity Jul page 76 ARC-12435 Algebraic model of turbulence for internal !low Aug page 63 ARC-12544 Computed lurbulent !low In a turnaround duct Oct page 82 ARC-12552 90 Navler-Stokes simulation of wind-tunnel !low Oct page 85 ARC-12193 Numerical aerodynamic simulation program Oct page 80 ARC- I 2245 Speeding convergence in Simulations of hypersonic !low Oct page 82 ARC-I 260 I Compulalion of !low in a turbine stage on a refined grid Nov page 90 ARC-I 2444 A general-coordinate formulation for boundary- layer !low Dec page 59 ARC-I 2465 Mathematical models of lurbulence in hypersonic !low Dec page 67 ARC-I 2609 FLOW MEASUREMENT Measurements of boundary layers on a compressor blade Apr page 83 LEW-1 4748 FLOW REGULATORS Pressure-actuated flow- conl rol valve Nov page 74 MFS-28513 FLOW STABILITY Growth of instabilities in two types of mixing layers Aug page 75 ARC-I 2567 FLOW VELOCITY New sensors for !low velocity and acoustics Dec page 76 ARC-12577 FLOW VISUALIZATION Point-diffraction interferometer for !low experiments Mar page 34 ARC-12489 Twin-mirrored galvanometer laser-light-sheet generator May page 30 LAR-14248 Liquid-crystal coats help make !lows visible Aug page 65 LAR-14342 Digita l image velocimetry Nov page 96 ARC-I 2474 Vapor-screen-density controller Nov page 38 LAR-14099 Processing particles-streak imagery on a personal computer Dec page 69 ARC-12267 FLUID DYNAMICS Semiautomatic design of zonal computational grids Feb page 52 ARC-12322 Simulation of !low in a turbine cascade Feb page 58 ARC-12551 Overview of aerother- modynamlcs of hypersonic !light Jul page 51 ARC-12217 , Adaptive grids for computations of three- dimensional !lows Aug page 66 ARC-12479 Experiments to verify computed !lows Nov page 80 ARC-I 2231 Artificial intelligence in computational fluid dynamics Dec page 73 ARC-12445 FLUID FLOW High-resolution computa- tions of hypersonic flows Feb page 57 ARC-12254 Exterma prirlClples of dissipation in Muids Jul page 48 ARC- I 23 I 8 Improved ultrasonic transducer for measuring cryogenic flow Nov page 78 MFS-29687 flUIDIZED BED PROCESSORS Fluidized-bed silane- decompoSition reactor Nov page 63 NPO-18014 FLUORESCENCE Reactive !luorescent dyes for urethane coatings Oct page 44 NPO-I 8038 FlUITER Placing control surfaces to suppress aeroelastic flutter Jul page 71 ARC-12411 Flutter spoilers Sep page 93 LAR-14117 FOREST FIRES Measuring wildfires from aircraft and satellites Feb page 40 ARC-12132 FORMING TECHNIQUES Multipiece mandrel for spray-forming complex parts Mar page 57 MFS-29680 FORTRAN Source-code-analyzing program Mar page 46 GSC-13268 Graphics software for VT terminals Jul page 64 MFS-27214 Characterizing compulers and predicting computing times Sep page 60 ARC-12434 Library of subprograms in FORTRAN 77 Dec page 55 NPO-18120 FOURIER TRANSFORMA- TION Transfer functions via Laplace- and Fourier-Borel Iransforms Jan page 52 ARC-12295 FTIR speclroscopic characterization of II-VI superconductors Apr page 55 MFS-27234 Transfer lunctions via Laplace- and Fourier- Borel transforms Sep page I 12 ARC-12295 Characterizat ion of electrical response of photodetector Dec page 24 GSC-13349 FRACTURE MECHANICS Fatigue-crack-growth computer program Apr page 74 MSC-21669 Probabilisticlfracture- mechanics model for service Ii Ie Jul page 77 MFS-27237 FRACTURES (MATERI- ALS) Mode-II-fracture specimen and holder Apr page 80 LEW-14964 FRAMES Program for elasloplastic analyses of plane frames Aug page 59 LEW-14889 FRAMES (DATA PROCESSING) Effects of frame rates in video displays Aug page 32 ARC-I 2358 FREQUENCY ANAL VZERS Two-dimensional acousto- optical spectrum analyzer SlIp page 72 N PO- 18092 FREQUENCY STANDARDS Trapped-mercury-ion frequency standard Jun page 55 NPO-1 7456 FREQUENCY SYNCHRONI- ZATION Diplex fiber-optic link for frequency and time signals Jun page 39 NPO-1 8180 FRfCTION MEASUREMENT Measuring adhesion and friction forces Jan page 39 LEW-14903 FUEL CELLS Making three-layer solid electrolyte/electrode sandwiches May page 67 NPO-17078 Ionizable-substance detector Dec page 38 MFS-285 I 5 FUEL FLOW REGULA- TORS Pressure-actuated !low- control valve Nov page 74 MFS-28513 FUNCTIONS (MATHEMAT- ICS) Recursive inversion by fin ile-impulse-respons.: filters Jan page 51 ARC-12247 FURNACES Modified furnace makes more silicon ribbon Feb page 64 N PO-17350 Acoustic levitator with furnace and laser heating Oct page 95 N PO-18035 G GALLIUM ARSENIDES V-grooved GaAs solar cell Feb page 16 LEW-14954 Formation of ohmic contacts on epitaxial GaAs Mar page 58 NPO-17795 Improved planar Schottky diode May page 24 GSC-13205 Alternative AI,Ga" AslGaAs transistors for neural networks Sep page 26 NPO-18177 High-gain AI,Ga" AslGaAs transistors for neural networks Sep page 24 NPO-18101 GALLIUM ARSENIDE LASERS High-power AIGaAS quantum-well lasers on Si substrates Sep page 26 NPO-17988 Self-heterodyne laser- spectrum analyzer Sap page 66 GSC-13397 GAMMA RAY OBSERVA- TORY Simulating dynamics of the Gamma-Ray Observatory salellite Apr page 76 GSC-13293 1991 Annual Subject Index GAMMA RAYS Microscope would Image x and y rays Sep page 71 MFS-28484 GAMMA RAY TELE- SCOPES Telescope would Image x and y rays Sap page 70 MFS-28482 GARMENTS Garment would provide variable cooling Jul page 44 MSC-21531 GAS CHROMATOGRAPHY GCIMS gas separator operates at lower temperatures Jun page 50 NPO-17930 GAS DISSOCIATION Effects of molecular processes on trim angles Apr page 62 ARC-I 2566 GAS DYNAMICS High-resolulion numerical simulation of shock waves Jul page 74 ARC-11730 GAS FLOW High-resolution computa- tions of hypersonic !lows Feb page 57 ARC-12254 GAS LASERS Automatic rejection of multi mode laser pluses Dec page 24 NPO-17777 GAS SPECTROSCOPY Computer processing of lunable-diode-Iaser spectra May page 28 NPO-18019 GAS TUNGSTEN ARC WELDfNG Fast. nonspattering inert-gas welding Feb page 61 MFS-29648 Compact gasltungsten arc welding torch Jun page 108 MFS-29668 Self-aligning sensor- mounting fixture Jun page 107 MFS-29663 Automatic control of lenglh of welding arc Nov page 91 MSC-21473 Diamond-coated wire- feeding nozzle Nov page 93 MFS-29714 Jointed holder for welding electrodes Nov page 95 MFS-29739 Smaller coaxial -view welding torch Dec page 82 MFS-29744 GASKETS Long-lived. replaceable low- pressure seals Sep page 98 MFS-28521 GATES (CIRCUITS) Associative-memory array of optical logiC gates May page 30 NPO-17997 GEARS "Bearingless" bull gear Apr page 90 LEW-1491 1 Torque-splitting gear drive Apr page 90 LEW-14908 GENE EXPRESSION Cloned hemoglobin genes enhance growth of cells Jan page 54 NPO-17517 Envlronmenlal control of a genetic process Jan page 54 NPO-17576 GENITOURINARY SYSTEM Ultrasonic device monitors fullness of the bladder Sap page I 15 LAR-13689 GEODESY Estimating baselines from constrained data on GPS orbits Nov page 40 NPO-18173 GEOMETRICAL OPTICS Computing performance of an optical system Jul page 60 GSC-13128 GEOTHERMAL ENERGY UTILIZATION Vapor-resistant heat-pipe artery Jun page 61 MSC-21492 GERMINATION Capillary-effect root- environment system Dec page 92 KSC- I 1350 GIMBALS Unbalanced rotating masses for scanning Sap page 100 MFS-28425 Flexure bearing reduces startup friction Nov page 72 LAR-14348 GLARE Variable-vision sun visor Jul page 44 LAR-14147 GLOBAL POSITIONING SYSTEM Digital accumulators in phase- and frequency- tracking loops Aug page 30 NPO-17909 Estimating baselines from constrained data on GPS orbits Nov page 40 NPO-18173 GOLAY DETECTOR CELLS Characterizallon of electrical response of photodetector Dec page 24 GSC-13349 GRAPHITE Apparatus for chemically treating graphite fibers Jun page I 15 LAR- I 3959 GRAPHITE-EPOXY COMPOSITES Damping of vibrations in graphite/epoxy struclures Jul page 74 MFS-27228 Damping of vibrations in graphite/epoxy structures Jul page 74 MFS-27228 GRATINGS (SPECTRA) Ruling blazed, aberration- corrected diffraction gratings Oct page 97 GSC-13240 Multiaperture spectrometer Dec page 38 NPO-1801 I Two-period gratings for surface-emitting lasers Dec page 26 NPO- I 8054 GRAVITY ANOMALIES Computing gravitational bumps from repeating-orbit data May page 52 NPO-17925 GRAZING INCIDENCE TELESCOPES Telescope would image x and y rays Sep page 70 MFS-28482 GRIT Grit blasting scribes coats for tests of adhesion NASA Tech Briefs, January 1992 1991 Annual Subjecllndex Jul page 84 MFS-28452 GROUND BASED CONTROL Knowledge-based flighl- slalus monitor Dec page 31 ARC-12712 GUIDANCE (MOTION) Back azimuth guidance In departures and missed approaches Jul page 39 ARC-12611 GYROSCOPES Block Lanczos algorilhm lor gyroscopic systems Aug page 75 ARC-12147 H HALL EFFECT MagneUHall-ellect random- access memory Nov page 28 NPO-17999 Rugged direct-current transducer Dec page 28 NPO-17957 HAND (ANATOMY) Prosthetic hand lifts heavy loads Feb page 69 MFS-28465 Rotationally actuated prosthetic hand Feb page 69 MFS-28426 Direct-link prehensor Dec page 78 ARC-11666 HANDLING EQUIPMENT Quick-acting closure and handling system Mar page 54 LAR-13774 Heavy-workpiece handler for vacuum plasma spraying Oct page 99 MFS-28522 HANKEL FUNCTIONS QR factorization in the partial -realization problem Apr page 98 ARC-12284 HARDWARE UTILIZATION LISTS Systematic Identification of discrepant hardware Jun page 58 MFS-29525 HARMONIC GENERATORS Organometallic salts generate optical second harmonics Jun page 54 NPO-I7730 HEART Numerical simulation 01 1I0w through an artificial heart Dec page 66 ARC-12478 HEAT EXCHANGERS Two-phase bidirectional heat exchanger Mar page 49 GSC-13287 Salt IlIler lor making covered channels Sep page 103 MFS-29729 Expert system for heat exchanger Ocl page 90 NPO-I7991 HEAT FLUX Integral plug-type heat-flux gauge Aug page 72 LEW-I4967 HEAT OF FUSION Correlating DSC and x-ray measurements of crystallinity Sep page 77 NPO-17958 HEAT PIPES Higher-performance ambienHemperature heat pipe May page 57 MSC-21515 Vapor-resistanl heal-pipe artery Jun page 61 MSC-21492 Heat-transfer coupling for heat pipes Sep page 92 N PO-17863 HEAT PUMPS Nonazeotropic heat pump Mar page 51 MFS-26099 HEAT SHIELDING Tesls of lIexible multilayer insulations Jul page 58 ARC-12405 HEAT SINKS Effects of heat Sinks on VPPA welds Oct page 99 MFS-27240 HEAT TAPES Casting of multilayer ceramic tapes Jun page 110 NPO-I7166 HEAT TRANSFER Oscillating thermal sWitch Feb page 34 NPO-17125 High-power liquid-metal heat-transfer loop May page 35 NPO-18034 Effects of Interference on scattenng by parallel fibers Nov page 60 ARC-12530 HELICOPTER CONTROL Precise autohover control for helicopter Oct page 36 ARC-12243 HELICOPTER PERFOR- MANCE Computing the dynamiCS of helicopters Feb page 46 ARC-12337 Computer simulation of a small lurboshalt engine Mar page 55 ARC-12299 Calculating dynamics of helicopters and slung loads Aug page 71 ARC-12755 HELICOPTERS "Bearingless· bull gear Apr page 90 LEW-14911 Calculating flow through a helicopter rotor May page 55 ARC-I 2202 Research in helicopter noise Aug page 74 ARC-12171 HELMET MOUNTED DISPLAYS Helmet-mounted IIquld- crystal display Jul page 34 MSC-2 1460 HELMETS Protecting helmets and visors from chemicals Apr page 70 MSC-21503 HEMOGLOBIN Cloned hemoglobin genes enhance growth of cells Jan page 54 NPO-17517 Computation of facilitated transport of 0 , In hemoglobin Jun page 128 ARC-12417 HIGH LEVEL LANGUAGES General-purpose Ada software packages Feb page 51 NPO-17983 Ada namelist package May page 50 NPO-17984 HIGH PASS FILTERS Making high-pass filters for submillimeter waves Aug page 83 NPO-17992 NASA Tech Briefs, January 1992 HIGH TEMPERATURE SUPERCONDUCTORS Forming YBa,Cu,O,. superconductors on copper substrates Mar page 38 KSC-11448 Passivation of high- temperature superconduc- tors Apr page 69 NPO-17949 HOLOGRAPHIC INTERFEROMETRY Holographic Interferometry to measure three· dimensional 1I0w Jun page 60 ARC-11474 HORN ANTENNAS Megawatt square microwave feed horn Jun page 22 NPO-18025 HOSES Rotary coupling extends lije 01 hose Mar page 49 GSC-I3316 HOT-FILM ANEMOM- ETERS LamInar-separation sensor Mar page 50 LAR-14314 HOT ISOSTATIC PRESSING Crack-free, nondlstorting can for hot isostatic pressing Oct page 98 LEW-14990 HOUSEKEEPING (SPACECRAFT) Dishwasher for Earth or outer space Jul page 78 MSC-21442 HOUSINGS Laser welding of contoured thin-wall housings Mar page 57 MFS-29653 HOVERING Precise autohover control for a helicopter Oct page 36 ARC-12243 HUMAN FACTORS ENGINEERING YAMM-yet another menu manager Feb page 47 NPO-I7769 h-Parameter analysis of teleoperators Jun page 97 NPO-17527 HUMAN PERFORMANCE Human error in complex systems Apr page 101 ARC-12424 HUMAN TOLERANCES Ellect of bed rest on tolerance to acceleralion Mar page 68 ARC-12400 HYDROGEN Real -gas properties of air and air-plus-hydrogen mixtures Jan page 30 ARC-12275 HYDROGEN EMBRITTLEMENT Alloy has high fatigue strength In hydrogen Nov page 62 MFS-28464 HYDROPONICS Closed-cycle nutrient supply for hydroponics Jul page 90 MSC-21655 Capillary-effect root- environment system Dec page 92 KSC-11350 HYDROSTATICS Modifications of hydrostatlc- beanng com puler program Apr page 89 MFS-29638 This brochure gives you detailed infor- mation about the industry's finest noise killers- SONEXacoustical sheets, baffles andceilingtiles, Foryourfree copy, use the reader service number below,Orcall this numbertoll-free today. 1·800·662·00J2. illlHvck ~'99 ',lIlbnKk,lnc. Circle Reader Action No. 466 rr=~============-::==--~~ Now you can accurately measure temperature from -5£P C to 350£P C without contact! Choose from two new Mikron infrared tempera- ture transmitters - the M21 OLS or the M77LS - specifically designed for research and laboratory applications, Their through-lens sighting and variable focussing features permit precision pinpoint- ing of the target area, M210LS is a broad temperature range system covering temperatures from -50°C to 2500°C, The M77LS transmitter is a high temperature 2-color instrument that is inde- pendent of emissivity and covers ranges from 550°C to 3500°C, 80th systems are available with an auxiliary electronics processing module, or can be connected to your existing controls_ Send today for more information, MIKRON INSTRUMENT COMPANY, INC, 445 W, Main St., Wyckoff, NJ 07481 U,S,A, Tel. 201-891-7330 • FAX: 201-891-1205 TELEX: 361870 • TOLL FREE HOT-LINE: 800-631-0176 Circle Reader Action No. 390 91 HYPERBOLIC DIFFEREN- TIALEQUATIONS Overview of methods for computalion of shocks Jul page 74 ARC-12667 HYPERSONIC FLIGHT Effects of molecular processes on trim angles Apr page 62 ARC-12566 Overview of aerother- modynamics of hypersonic flight Jul page 51 ARC-I2217 Aerodynamics of missiles: present and future Oct page 83 ARC-t2188 HYPERSONfC FLOW High-resolulion computa- lions of hypersonic flows Feb page 57 ARC-12254 Artificial dissipation In computation of hypersonic flows Jun page 124 ARC-12260 Algor~hm computes hypersonic flow of air Sep page 76 ARC-12623 Computed hypersonic flow about a sharp cone Oct page 85 ARC-12675 Speeding convergence in simulations of hypersonic flow Oct page 82 ARC-12601 Computed hypersonic viscous flows over delta wings Dec page 70 ARC-12179 Malhematical models of turbulence in hypersonic flow Dec page 67 ARC-12609 HYPERSONIC VEHICLES Transpiration cooling of hypersonic blunt body Aug page 57 ARC-12383 HYPERSONIC WIND TUNNELS Laser spectroscopic measurement of temperature and density May page 43 ARC-12719 Adjustable pitot probe Aug page 70 LAR-14232 HYPERVELOCITY LAUNCHERS Superconducting magnelic projectile launcher Mar page 48 NPO-I7746 IBM COMPUTERS Micro channellMultibus-li interface circutl Jul page 24 MSC-21506 IMAGE ANALYSIS Human expertise helps computer classify images Oct page 110 MSC-21737 Dig~al image velocimetry Nov page 96 ARC-12474 IMAGE ENHANCEMENT Liquid-cryslal light valve enhances edges In images Apr page 54 NPO-17768 IMAGE PROCESSING Displaying images of planets Jun page 57 NPO-17977 Improved remapping processor for digital imagery Jul page 26 MSC-21481 92 Detection of molion with a phase-conjugate mirror Oct page 40 NPO-I7784 Digtlal image velocimetry Oct page 78 ARC-1277 4 Improved interferometric photorefractive optical processor Oct page 39 NPO-I7773 Photorefractive crystal compresses dynamic range of Image Oct page 37 NPO-18098 Video image communication and retrieval-updated Nov page 66 NPO-t8076 Processing particles-streak Imagery on a personal computer Dec page 69 ARC-t 2267 Program Processes SAR data Dec page 52 NPO-18048 IMAGERY Half-tone video Images of drifting sinusoidal gratings Apr page 46 ARC-12414 iMAGING RADAR Status of imaging radar polarimetry Jan page 30 NPO-17890 Improved radiometric correction for SAR images Oct page 37 NPO-17931 IMAGING TECHNIQUES Heterojunction-Internal- photoemission infrared detectors Jan page 22 NPO-17879 Imaging microscope for "water-window" x rays Jul page 40 MFS-28485 Video recording of images in laser remote sensing Jul page 26 GSC-13398 Monitoring welding images and data simultaneously Aug page 29 MFS-29772 Spatial light modulator would serve as electronic iris Aug page 22 MFS-29758 Low-noise charge-coupled device Oct page 20 NPO-18031 Altering interline transfer in a CCD to reduce saturation Dec page 30 NPO-17935 IMIDES New synthesis of high- performance bismaleimides Jul page 54 LAR-13958 IMPACT LOANS Software models impact stresses Nov page 65 MFS-29628 IMPACT TESTS Impact damage in carboni epoxy and carboniPEEK composites Apr page 72 MFS-27245 INCOMPRESSIBLE FLUIDS Pressure fluctuations in simulated turbulent channel flow Oct page 80 ARC-12597 fNCOMPRESSIBLE FLOW Faster algorithm for computation of incompress- ible flow Feb page 52 ARC-12370 Incompressible, viscous flow about an ogive/cylinder Aug page 73 ARC-11793 Methods of simulation of incompressible flow Dec page 74 ARC-12199 INDUCTORS Spacing windings evenly in toroidal inductors May page 69 NPO-17830 INDUSTRIAL MANAGE- MENT Tracing and control of engineering requirements Dec page 56 NPO-18215 INERT ATMOSPHERE Trailing shield for welding on pipes Dec page 82 MFS-29743 INFERENCE Parallel inferencing for rule- based expert systems Mar page 62 N PO-18004 INFORMATION PROCESSING (BIOLOGY) Processing of visual information in primate brains Mar page 67 NPO-17900 INFORMATION THEORY Algorithm derives rules from data Nov page 96 NPO-1 8114 INFRARED DETECTORS Heterojunction-internal- photoemission infrared detectors Jan page 22 NPO-17879 Multiple-quantum-well intersubband infrared detector Jan page 25 NPO-17962 Phototransistors for long- wavelength infrared May page 26 NPO-18029 Test adapter for infrared detectors Jul page 73 A'RC-11389 Hole-impeded-doping- superlattice LWIR detectors Sep page 22 N PO-17880 IrllrSijSi Schottky-barrier infrared detector Oct page 22 NPO-18144 Si,_.Ge/Si infrared photodiodes Oct page 26 NPO-17950 Proceedings of infrared- detector workshop Nov page 60 ARC-12851 SillrSi, Schottky-barrier infrared detectors Dec page 22 NPO-180271 17946 INFRARED IMAGERY Estimating the SNR of AVIRIS data Feb page 66 ARC-12361 INFRARED SPECTROS- COPY FTI R spectroscopic characterization of II-VI superconductors Apr page 55 MFS-27234 Stirling-cycle cooling for tunable diode laser Aug page 16 N PO-18045 INJECTION LASERS Self-injection locking of diode lasers Jun page 46 NPO-17665 INJECTORS Vacuum powder injector Oct page 93 LAR-14179 INSPECTION Improved metallography of thermal-barrier coallngs Apr page 56 LEW-15006 Flexible interior-impression- molding tray May page 63 MFS-29579 Penetrant-Indication- measuring compass Jun page 110 MFS-29643 Computerized profilometer for inspection of wetds Aug page 79 MFS-28548 Lighted, folding inspection mirror Oct page 92 MFS-28457 INSTRUMENT COMPEN- SATION Accounting for nonlinearijy in a microwave radiometer May page 40 NPO-17451 INSTRUMENT PACKAGES Adjustable support for instrument package Oct page 77 GSC-13381 INSULATION High-temperature insulating gap filler Jul page 52 MSC-21644 Tests of flexible multilayer insulators Jul page 58 ARC-12405 INTEGRATED CIRCUITS Multiple-bit errors caused by single ions Jul page 38 NPO-18075 Designing accelerated tests of electromigration Aug page 54 NPO-18012 Five-segmenl interconnec- tion for electromigration tests Aug page 18 NPO-18105 Addressable-matrix integrated-circuit test structure Nov page 32 NPO-18162 tNTERFACES Interface circuit for printer port Jun page 26 LAR-13950 INTERFEROMETERS Point-diffraction inlerferometer for flow experiments Mar page 34 ARC-12489 Equal-path, phase-shifting, sample-point Interferometer Apr page 61 NPO-17913 Broadband, achromatic Twyman-Green interferometer Oct page 38 NPO-17675 INTERFEROMETRY Two-wavelength interferometric keratometer Feb page 39 NPO-17537 Improving sparse-aperture interferometric radiometry Mar page 26 NPO-17886 Detection of motion with a phase-conjugate mirror Oct page 40 NPO-I7784 Improved interferometric photorefractive optical processor Oct page 39 NPO-17773 1991 Annual Subject Index Single-exposure long- eqUivalent-wavelength interferometry Nov page 52 N PO-17580 INTERROGATION Programmable maintenance processor for XAIDS Oct page 31 ARC-12164 INVENTORY MANAGE- MENT Bar-code-scribing tool Mar page 58 MFS-2844 t INVISCfD FLOW Calculating viscous/inviscid interactions Apr page 85 ARC-12115 IODINE Source and sink of iodine for drinking water Oct page 116 MSC-21739 ION BEAMS Ion processes modify tribological properties of surfaces Apr page 96 LEW-14865 IRIDfUM Molecular-beam epitaxy of IrSi, Feb page 60 NPO-17953 Iridium/rhenium parts for rocket engines Jul page 54 LEW-14924 IrllrSijSi Schottky-barrier infrared detector Oct page 22 NPO-18144 IRISES (MECHANICAL APERTURES) Spatial light modulator would serve as electronic iris Aug page 22 MFS-29758 J JACOBI INTEGRAL Jacobi-integral method for two-body problem May page 56 MSC-21623 JET PUMPS Jet boost pumps for the Space Shuttle main engine May page 58 MFS-29673 JIGS Jig for compression- relaxation tests of plastics May page 53 MSC-21674 JOINING Five-segment interconnec- tion for electromigration tests Aug page 18 NPO-18105 JOINTS (JUNCTIONS) Bonding aramid rope to metal fitting Jan page 47 MSC-21618 Calculating scattering at Circular-waveguide junctions Jul page 20 NPO-17288 Distributed-computer system optimizes SRB joints Aug page 24 LAR-14311 Quick-connecVdisconnect joint for truss structures Sep page 102 MSC-21539 Dynamic analyses including joints of truss structures Dec page 62 LAR-14306 JOULE-THOMSON EFFECT Mixed-gas sorption Joule- Thomson refrigerator May page 38 NPO-17569 JOURNAL BEARINGS Bearing-cartridge damping seal Aug page 77 MFS-29657 JUNCTION TRANSISTORS Edge-geometry NbNlMgOI NbN tunnel junctions Oct page 18 NPO-17812 K KALMAN FILTERS The history of the Kalman finer Jul page 87 ARC-11734 KEVLAR (TRADEMARK) Bonding ararnid rope to metal frtting Jan page 47 MSC-21618 L LABORATORIES Controlling laboratory processes from a personal computer Sep page 88 LEW-1 4907 Facility measures magnetic fields Sep page 65 NPO-1 8187 LABYRINTH SEALS Computing flow in a labyrinth seal Jun page 98 MFS-29682 LAMINAR FLOW Making large suction panels for laminar-flow control Feb page 61 LAR-13844 LAMINATES Triangular element for analyzing elasticity of laminates Jul page 68 ARC-12534 LAND MOBILE SATELLITE SERVICE Multistage estimation of frequency and phase Jan page 27 NPO-17911 End-loaded, cavity-backed, cross-slot antennas Sep page 30 NPO-1 8100 LANDING MODULES Reusable manned lunar vehicle Nov page 89 MFS-28454 LAPLACE TRANSFORMA- TION Transfer functions via Laplace- and Fourier- Borel Iransforms Sep page 112 ARC-12295 LARGE SPACE STRUCTURES Low-frequency suspension system for large space structures Jun page 62 LAR-14149 Dynamic analyses including jOints of truss structures Dec page 62 LAR-1 4306 LASER APPLICATIONS Video recording of Images in laser remote sensing Jul page 26 GSC-13398 Compensaling for movement of eye in laser surgery Nov page 46 MSC-21509 LASER DOPPLER VELOCIMETERS Laser velocimeter for outdoor or wind-tunnel measurements NASA Tech Briefs, January 1992 1991 Annual Subject Index Jul page 40 ARC-12592 Modification of catadioptric telescope for laser velOCImetry Aug page 56 ARC-12610 LASER tNTERFEROM- ETRY Point-diffraction interferometer for flow experiments Mar page 34 ARC-12489 Single-exposure long- equivalent-wavelength interferometry Nov page 52 NPO-17580 LASER MATERIALS Long-lifetime laser materials for effective diode pumping Feb page 42 LAR-I 3807 LASER MODE LOCKING Self-injection locking of diode lasers Jun page 46 NPO-17665 LASER MODES Automatic relection of multi mode laser pulses Dec page 24 NPO-17777 LASER SPECTROMETERS Computer processing of tunable-dlode-Iaser spectra May page 28 NPO-18019 LASER SPECTROSCOPY Laser spectroscopic measurement of temperature and density May page 43 ARC-12719 LASER WELDING Laser welding of contoured thin-waif housings Mar page 57 MFS-29653 LASERS Semiconductor laser With multilayer dielectriC reflector Feb page 18 NPO-17763 Lateral-grating DFB laser Mar page 22 LAR-13977 Low-loss coupler for microwave laser-diode modulation Apr page 22 LAR-t 3788 Acousto-optical filter can rapidly tune solid-state lasers Jun page 52 NPO-17891 Multiple integrated in-line diode lasers Nov page 34 LAR-I 4378 Two-period gratings for surface-emitting lasers Dec page 26 NPO-18054 LATCHES Thermally actuated unlatching mechanism May page 57 NPO-17601 Push-to-Iock, push-to- release mechanism Jul page 73 MSC-21520 LAUNCHERS Superconducting magnetic projectile launcher Mar page 48 N PO-I 7746 LEAD ACID BATTERIES Reinforced positive filler paste for leadlacld battenes Jan page 20 NPO-16991 lightweight, high-energy leadlacid battery Apr page 22 NPO-I 6962 LEAKAGE Rotary coupling extends lile of hose Mar page 49 GSC-13316 Dual-diaphragm tank with leakage-indicating drain Sep page 91 MSC-21703 LEARNING MACHINES Simplified learning scheme for analog neural network Feb page 26 NPO-17664 Modular, multilayer perceptron Mar page 3 I N PO-I 7860 LEAST SQUARES METHOD Polynomial transformations for discrete-time linear systems Sep page 110 ARC-12204 LEVITATION Microwave levilalion of small objects Sep page 109 N PO- I 8006 Acoustic levitator with furnace and laser heating Oct page 95 NPO-I 8035 LIFE (DURABILITY) Computing lives and reliabilities of turboprop transmissions Mar page 44 LEW-I 4905 LIFE SUPPORT SYSTEMS Software for design of life- support systems Aug page 89 ARC-12665 LIFT Pneumatic spoiler controls airfoil lift Nov page 71 ARC-11519 LIGHT BEAMS Twin-mirrored-galvanometer laser-light-sheet generator May page 30 LAR-14248 LIGHT EMITTING DIODES Nonintruslve measurement of temperature of LED junction Mar page 33 GSC-I 3339 Self -injection locking of diode lasers Jun page 46 NPO-17665 LIGHT MODULATION Spatial light modulator would serve as electronic iris Aug page 22 MFS-29758 LIGHT VALVES liquid-crystal light valve enhances edges In images Apr page 54 N PO-I 7768 LIGHTNING Circuit detects faint flashes against bright background Sep page 19 MFS-28466 Geographical variations in measured lightning lields Sep page 78 KSC-I 1449 LINEAR EQUATtONS QR factorization in the partial -realization problem Apr page 98 ARC- I 2284 LINEAR FILTERS The history of the Kalman filter Jul page 87 ARC- I 1734 LINEAR SYSTEMS Stress stiffening 01 STAR- DYNE plate elements Jul page 69 MFS-29738 Design and analysis of linear control systems Aug page 59 KSC-I I 376 Polynomial transformations for discrete-time linear systems Sep page t 10 ARC 12204 NASA Tech Briefs, January 1992 Soflware for multivariable frequency-domain analysis Sep page 87 LAR-141 19122 R-parameterization of linear feedback systems Oct page I 06 ARC-I 2369 Relative-arror-covariance algorithms Oct page I 12 NPO- I 7956 LINEARIZATION Computing linear mathematical models of aircraft Mar page 45 ARC-12422 LINKAGES Low-thermal-conduction links for silicon sensors Feb page 38 GSC-13321 Thermally actuated unlatching mechanisam May page 57 NPO-17601 LIQUID CRYSTALS Liquid-crystal light valve enhances edges in images Apr page 54 N PO-I 7768 Helmet-mounted liquld- crystal display Jul page 34 MSC-21460 Liquid-crystal coats help make flows visible Aug page 65 LAR-14342 LIQUID-GAS MIXTURES Estimating liquid and gas contents in a tank May page 51 MSC-21500 Separation of liquid and gas in zero gravity Oct page 91 KSC-11387 LIQUID METALS High-power liquid-metal heat-transfer loop May page 35 NPO-18034 LfQUID PHASE EPITAXY Improved boat for liquid- phase epitaxy Jul page 80 LAR-14199 LIQUIDS Calculating thermophysical properties of 12 fluids Dec page 52 MSC-21664 LITHIUM Lithium cells accept hundreds of recharges Jun page 28 NPO-17676 LOADS (FORCES) Mode-ii-fracture specimen and holder Apr page 80 LEW-14964 Strain center for analysis of forces Aug page 68 NPO-I 7966 Deflection and stress in preloaded square membrane Sep page 96 GSC-13367 LOCAL AREA NETWORKS Quad-port transceivers for a dual-CRR LAN Feb page 28 NPO-1754 I LOCKING Self-injection locking of diode lasers Jun page 46 NPO-I 7665 LOCKS (FASTENERS) Lock for valve stem Dec page 63 MFS-29764 LOGIC CIRCUITS Simplified learning scheme for analog neural network Feb page 26 NPO-17664 (fl.Jjiaw7ti.:r.*in~il l· kJ Over 1000 pages of high-tech innovations developed by NASA, the departments of Defense and Energy, and other key govern- ment agencies_ Two-volume set features 120 papers describ- ing new inventions available to industry in: t/ Biotechnology t/ 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Phn: 61 21571·3121 Telex: 687-9025 FAX: 61 2/571-0927 Circle Reader Action No. 308 93 3M Announces Double-Coated Foil Shielding Tape Copper foil base with electrically -conductive adhesive on both sides for reliable point-to-point conductivity. Austin , Tex . - This new UL Recognized tape has a multitude of uses in electronic design , test , and QC laboratories where good adhesion and reliable conductivity are required . Applications include shielding PC boards , microwave antennas, and dis- play boards; grounding, bonding and static charge draining. Scotch™ Brand Electrical Tape #1182 features excellent shield- ing over a fre- quency range from 1 MHz to 1 GHz , measured in the Near Field using a modified Mil Std 285 test procedure. In IC applica- tions , #1182 tape also provides an excellent heat- conductive path Copper Foil (adhesive both sides) Scotch Brand Foil Shielding Tape #11 82 is supplied on a liner that permits easy handling and dispensing in either ra ndom or definite lengths. to protect sensitive areas from excessive thermal exposure. The tape is rated at Class 155 0 C continuous operating temperature. It is supplied on a liner that permits easy handling and die-cutting without seriously wrinkling the foil backing. A line of stand- ard dispensers is available to increase productivity. The dispensers are available with liner take-up attachments and can de- liver either random or definite lengths. Custom application equipment can be designed for automatic or semi automatic production . For more information about all 3M foil tapes , contact a 3M Electrical Specialties Division representative or authorized dis- tributor or call 1-800-233-3636. 3M Electrical Specialties Division 3NI PO Box 2963 Austin, TX 78769·2963 94 Circle Reader Action No. 606 Associative·memory array of opncal logIC gates May page 30 NPo-17997 Orthogonal patterns In a binary neural networl< May page 72 ARC·12454 LOOPS Dlgrtal accumulalors in phase· and frequency· tracking loops Aug page 30 NPO·17909 Digital phase·locked loop WIth phase and frequency feedback Nov page 36 NPO-17722 LOW NOISE Low-noise charge-coupled device Oct page 20 NPO-18031 LUBRICATION Lubrication of nonconformal contacts Feb page 57 LEW-1 4882 LUMINOUS INTENSITY Circuit detects fainl flashes againsl bright background Sep page 19 MFS-28466 LUNAR SPACECRAFT Reusable manned lunar vehicle Nov page 89 MFS-28454 M MACHINERY Improved computation of dynamic stresses Jan page 39 MFS-29745 MACHINING Electrical-discharge machining with additional axis Feb page 63 MFS-29630 Multipiece mandrel lor spray- forming complex parts Mar page 57 MFS-29680 MAGNESIUM ALLOYS Plasma spraying reclaims compressor housings Jan page 44 LEW-14899 MAGNETIC BEARINGS Improved notch IiIter for synchronous-response control Apr page 48 LAR-14173 Magnetic-bearing test fixture Nov page 82 LAR-I4312 MAGNETIC FIELDS Facility measures magnetic fields Sep page 65 NPO-18187 MAGNEnC STORAGE Magnetic analog random- access memory Nov page 30 NPO-17998 MAGNETIC TAPES Matrix encoding for correction of errors Oct page 108 NPO-t 7834 MAGNETO-OPTICS Optical isolators wilh transverse magnet Feb page 36 LAR-14092 MAGNETORESISTIVITY Fast magnetoresistlve random-access memory Apr page 32 NPO-17954 MAINTENANCE Programmable maintenance processor for XAIDS Oct page 31 ARC-12164 Repairing a shaft prone to fatigue Oct page 94 MFS-28518 MANAGEMENT TraCIng and control of engineering requirements Dec page 56 NPo-18215 MAN-COMPUTER INTERFACE YAMM-yel another menu manager Feb page 47 NPo-l7769 MANDRELS Multipiece mandrel for spray-forming complex parts Mar page 57 MFS-29680 MANIFOLDS (MATHEMAT- ICS) Self-motion manifolds of redundant manipulators Sep page 101 NPO-17965 MANIPULATORS Conlugate gradient algorithms for manlpulalor simulation Apr page 84 NPO-17929 EffiCient computalion of inertia matrix of a manipulator May page 70 NPO-17545 Segmented arm lor positioning and assembly May page 58 MSC-21512 Analysis 01 control 01 cooperating robot arms Jul page 86 NPO-I7789 Experiences w~h the JPL telerobot testbed Aug page 30 NPO-17928 Spatial-operator algebra lor robotic manipulators Aug page 88 N PO-I7770 Anthropomorphic robot hand and teaching glove Sep page 99 GSC-13244 Parallel-processing algorithms lor dynamics 01 manipulators Sep page 111 NPO-I7718 Self-motion manilolds 01 redundant manipulators Sep page 101 NPO-17965 Redundant robot can avoid obstacles Oct page 86 NPO-17852 Sensing temperatures via prostheses and manipulators Oct page 35 MSC-21676 System lor research on multiple-arm robots Oct page 30 NPO-17971 Viselike robotic gripper Oct page 86 GSC-13323 Direct-link prehensor Dec page 78 ARC-11666 MAN-MACHINE SYSTEMS h-Parameter analysis of teleoperators Jun page 97 NPO-17527 MANNED ORBITAL TELESCOPES Aiming schedule lor orbiting astrometric telescope Aug page 57 ARC-12103 MANNED SPACECRAFT Carrying humans to and Irom Mars Aug page 78 MFS-28453 Reusable manned lunar vehicle Nov page 89 MFS-28454 1991 Annual Su iect Index MAPPING Improved remapping prooessor lor digrtal Imagery Jul page 26 MSC-21481 Program computes universal transverse Mercator projection Jul page 62 NPo-18086 MAPS Helicrty-density and norrnalized-helicity maps of flows Aug page 62 ARC-12464 MARKING Bar-code-scnblng tool Mar page 58 MFS-28441 MARKOV PROCESSES Hidden-Marldemarh of their ~ monufocturers. Company nomes lilted ore trcdemarb or InJde names of Iiiei, __ YO companies. o Cas>yrigh. 1991 NaIiortcllrutruments Corporation. All riglits '"-"d. Circle Reader Action No. 581 105 INNOVATIVE ENVIRONMENTAL ENCLOSURES FOR SCIENCE AND INDUSTRY REGULATED WORK AREAS • Pilot Plant Operations • Environmental Enclosures • Clean Room Applications • Hazardous Procedures • NEW MOBILAB • NEW MODULAB Reque.' new celli/Oil de.crib/nll HEMCO'S [> Unlleb Rellu/aled Work Are ... cell 816-796-2900 is· =--, ~- '~~~=::.~. HEMCO CORPORATION 111 N. Powell ee, MO 64056 USA Integrated analysis capablli1y program Dec page 54 GSC·13341 STRUCTURAL MEMBERS Open·section composite structural elements Feb page 45 MFS-26112 STRUCTURAL VtBRATION Catculating transient vibrations of coupled substructures May page 54 MFS-28477 Two techniques for suppressing vibrations in structures Dec page 60 NPO-17889 STRUTS Composite struts would damp vibrations Apr page 79 NPO-17914 SUBMtLLtMETER WAVES Quasi-optical millimeter· wavelength resonator Jun page 16 NPO-17919 Making high-pass finers for submillimeter waves Aug page 83 NPO-17992 SUBSONtC WIND TUNNELS Experiments on schemes for adaptive·wall wind tunnels Dec page 72 ARC-12116 SUBSTRATES Lightweight substrates for mirrors Jan page 32 NPO·17854 Preventing vapor deposition on the backs of substrates Jan page 44 LAR-14071 SUNLIGHT Circle Reader Action No. 616 Variable·vision sun visor ____________________________ -----j Jul page 44 LAR·14147 ~~~~~~--~Z~hc~onia Fibe .... Based Materials offer limitless possibilities When you need exceptionally high tempera- tures, low thermal conductivity or resistance to chemical attack, choose one of Zircar's Zirconia fiber-based materials. Bulk fibers, flexible textiles, rigid boards or cylinders: nobody knows how to take Zirconia to the limit like Zircar! (~\) ® Z!!!£~r. P.O. Box 458, Florida, NY 10921 Tel: (914) 651-4481 Fax: (914) 651-3192 106 Circle Reader Action No. 323 SUPERCONDUCTORS Forming YBa,Cu,O,., superconductors on copper substrates Mar page 38 KSC-11448 Passivation of high· temperature superconduc· tors Apr page 69 NPO-17949 Performance of supercon- ducting-cavity maser Jun page 30 NPO·18175 SUPERSONtC COMBUS- TION RAMJET ENGtNES Simulating the performance of a scramjet Mar page 42 ARC·12338 SUPERSONIC WtND TUNNELS Experiments on schemes for adaptive-wall wind tunnels Dec page 72 ARC-12116 SUPPORTS lightweight composite core for curved composite mirrors Jun page 116 NPO·17858 Adjustable support for instrument package Oct page 77 GSC-13381 SURFACE CRACKS Penetrant-indlcatlon- measuring compass Jun page 11 0 MFS-29643 SURFACE FINISHING Smoother turbine blades resist thermal shock better Jul page 81 MFS·28472 Pressure roller for tape-lift tests Sep page 105 GSC-13230 1991 Annual Subject I ex SURFACE LAYERS Chemically layered porous solids Oct page 45 MSC-21487 SURFACE PROPERTIES Ion processes modify tribological properties of surfaces Apr page 96 LEW-14865 SURFACE VEHICLES Planning the route of a robotic land vehicle Mar page 61 NPO-17857 SUSPENDING (HANGtNG) Low-frequency suspension system for large space structures Jun page 62 LAR-14149 Zero-spring-rate mechanism/air suspension cart Aug page 69 LAR-14142 SWIRUNG Low-leakage inlet swirl brake Oct page 74 MFS·29608 SWITCHES Oscillating thermal switch Feb page 34 NPO-17125 Improved gas-gap heat switch Aug page 49 NPO·18136 Valve- and switch· monitoring computer program Nov page 98 MSC-21720 SWtTCHING CIRCUITS Driver circuit for high-power MOSFET's Nov page 28 LEW-15089 SYNTHETIC APERTURE RADAR Statistical partial calibration of polarimetric SAR imagery Feb page 40 NPO-17888 Polarization filtering of SAR data Apr page 58 NPO-17904 Estimating SAR Doppler shifts from homogeneous targets Oct page 102 NPO·17869 Estimating SAR Doppler shifts from quasi- homogeneous targets Oct page 105 NPO-17905 Improved radiometric correction for SAR images Oct page 37 NPO-17931 Ambiguity of Doppler centroid In synthetic- aperture radar Nov page 48 N PO-17943 Program Processes SAR data Dec page 52 NPO-18048 SYNTHETIC FIBERS Making solid aromatic polyimide fibers May page 44 LAR-14162 Superfiber for strong. light fabrics Sep page 80 MSC-21659 SYNTHETIC RESINS Polyphenylqulnoxalines via aromalic nucleophilic displacement Jan page 32 LAR-13988 Polyamide-Imldes made fromBTDA May page 48 LAR-13942 SYSTEMS ANAL YSfS Decomposing systems Into subsystems for design Oct page 69 LAR-1421 0 Computing avallabili1y and reliablli1y for a system Nov page 70 NPO-l6051 T TACTILE DISCRIMtNATlON Reduced-wiring tactile sensor Mar page 18 NPO-17872 TAKEOFF Analyzing takeoffs of powered-lift aircraft Oct page 83 ARC-11784 TANKS (CONTAINERS) Estimating liquid and gas contents In a tank May page 51 MSC-21500 Dual-diaphragm tank with leakage-indicating drain Sep page 91 MSC-21703 TAPS Hand broaching tool for use in confined areas Jun page 123 MFS·29669 TEACHtNG MACHINES Intelligent computerized training system Oct page 107 MSC-21381 TELECOMMUNICATION Munistage estimation of frequency and phase Jan page 27 NPO-17911 Burst-compression and - expansion for TDMA communication Jun page 40 LEW-15102 Transmitting reference radio signal on two optical carriers Jun page 32 NPO-18007 Stereoscopic configurations to minimize distortions Oct page 34 NPO-18028 Estimating rain attenuation In satellite computation links Dec page 48 LEW-14979 TELEMETRY Behavior of Costas loop in reception of telemetry Aug page 30 NPO-18084 System decommutes and disptays telemetry data Sep page 89 GSC-I3324 TELEOPERATORS Active compliance and damping in lelemanipulator control Apr page 48 NPO-17969 h-Parameter analysis of teleoperators Jun page 97 NPO-17527 Experiences w~h the JPL telerobot testbed Aug page 30 NPO-17928 Anthropomorphic robot hand and teaching glove Sep page 99 GSC-13244 Expert script generator Oct page 70 LAR-14065 Hidden-Markov-model analysis of telemanipulator data Oct page 87 NPO'I8000 Software for integration of EVA and telerobotlcs Oct page 69 NPO·18220 NASA Tech Brjefs, January 1992 1991 Annual Subjecllndex Software for supervisory and shared control of a robot Oct page 102 NPO-18116 Testbed for telerobotic servicing Oct page 32 NPO-18061 TELESCOPES System would keep telescope reflector segments aligned Apr page 40 NPO-17S03 Aiming schedule for omiting astrometric telescope Aug page 57 ARC-12103 Digital control of a telescope in an airplane Aug page 29 ARC-12399 Modification of catadioptric tetescope for laser veloclmetry Aug page 56 ARC-12610 TEMPERATURE CONTROL Higher-performance ambient-temperature heat pipe May page 57 MSC-21515 Vapor-resistant heat-pipe artery Jun page 61 MSC-21492 Transpiration cooling of hypersonic blunl body Aug page 57 ARC-12383 TEMPERATURE DISTRIBUTION Computing temperatures in optically pumped laser rods Jul page 63 LAR-14209 TEMPERATURE MEASUREMENT Nonintrusive measurement of tempera lure of LED junction Mar page 33 GSC-13339 Laser speclroscopic measurement of temperature and density May page 43 ARC-12719 Integral plug-type heat-flux gauge Aug page 72 LEW-14967 TEMPERATURE SENSORS Sensing temperatures via proslheses and manipulators Oct page 35 MSC-21676 TEMPERING Gradient tempering of bearing races Sep page 107 MFS-28496 TENSILE TESTS Layered plating specimens for mechanical tests Nov page 94 MFS-29718 TEST EQUIPMENT Experiences with the JPL telerobot testbed Aug page 30 NPO-17928 Push tester for laminated films Sep page 92 NPO-18063 Testbed for telerobotic servicing Oct page 32 NPO-18061 Magnellc-bearing test fixture Nov page 82 LAR-14312 Dynamic lester for rotor seals and bearings Dec page 80 MFS-28493 TEST FACILITIES TESTPATIERN GENERATORS Waveform-generating program Sep page 87 MFS-28408 TESTERS Addressable-matrix Inlegraled-circu it lesl structure Nov page 32 NPO-18162 THERMAL ANALYSIS Inlegrated analysis capability program Dec page 54 GSC-13341 THERMAL CONDUCTORS Thermal strap and cushion for thermoelectric coder Jun page 16 NPO-17806 THERMAL INSULATION Low-thermal-conduction links for silicon sensors Feb page 38 GSC-13321 Gauge measures th icknesses of blankets Mar page 47 MSC-21693 Tests of flexible multilayer insulations Jul page 58 ARC-12405 THERMAL RADIATION Script-factor modeling of absorption in a solar receiver Dec page 40 NPO-18018 THERMAL SHOCK Smoother tumine blades resist thermal shock better Jul page 81 MFS-28472 THERMAL STRESSES Temperature, thermal stress, and creep in a structure Nov page 81 ARC-12213 THERMISTORS Computed lomography for inspection of thermistors Jun page 111 MFS-29662 THERMOCOUPLES Thermocouple-signal- conditioning circuit Jul page 20 MFS-29695 THERMOELECTRIC COOLING Thermal strap and cushion for thermoelectric cooler Jun page 16 NPO-17806 THERMOELECTRIC POWER GENERATION TEM pump with external heat source and sink Jul page 79 NPO-17884 Heat-transfer coupling lor heat pipes Sep page 92 NPO-17863 THERMOPHYSICAL PROPERTIES Thermally actuated unlatching mechanism May page 57 NPO-17601 Caiculatlng thermophysical properties of 12 fluids Dec page 52 MSC-21684 THERMOPLASTIC RESINS Polyphenylquinoxalines via aromatic nucleophilic displacement Jan page 32 LAR-13988 Tough, high-performance, Ihermoplastic addition polymers May page 46 LAR-1oooo New polylmide has many Facility measures magnetic uses fields Sep page 85 LAR-14163 Sap page 65 NPO-18187 NASA Tech Briefs, January 1992 THERMOSTATS Improved gas-gap heat switch Aug page 49 NPO-17928 THICKNESS Gauge measures thicknesses 01 blankets Mar page 47 MSC-21693 THIN FILMS Testing conductive films for cont inuity Feb page 41 NPO-17938 Electrochemical deposition of conductive polymers Apr page 84 NPO-17826 Push tesler lor laminated films Sep page 92 NPO-18063 DepOSition of diamondlike films by ECR microwave plasma Oct page 42 NP()'18094 Diamond-coated wire- feeding nozzle Nov page 93 MFS-29714 THREADS Tool removes coil-spring thread inserts Jun page 106 MFS-28432 THREE DIMENSIONAL BODIES Software for depiction of three-dimensional objects Dec page 55 MSC-21708 THREE DIMENSIONAL FLOW Holographic interferomelry to measure three- dimensional flow Jun page 60 ARC-11474 Adaptive grids for computations of three- dimensional flows Aug page 66 ARC-12479 TILES Detecting filler spaces under tiles May page 61 KSC-11411 TILT ROTOR AIRCRAFT Frequency-domain identification of aeroelastic modes Dec page 73 ARC-12407 TIME DIVISION MULTIPLE ACCESS Burst-compression and - expansion for TDMA communication Jun page 40 LEW-15102 TIME SIGNALS Diplex fiber-optic link for frequency and lime signals Jun page 39 NPO-18180 TIMING DEVICES Flexible generation of array- detector timing signals Oct page 35 GSC-13345 TOMOGRAPHY Computed tomography for inspection of thermistors Jun page 111 MFS-29662 TOOLING Verification of tooling for robotic welding Aug page 85 MFS-29725 TOOLS Alignment tool for inertia welding Mar page 59 MFS-29667 Bar-code-scriblng tool Mar page 58 MFS-28441 Hand broaching tool for use In confined areas Jun page 123 MFS-29669 Tool removes coil-spring thread inserts Jun page 106 MFS-28432 Staking pliers Sep page 104 MSC-21725 TORCHES Compact gas/tungslen-arc welding torch Jun page 108 MFS-29668 Plasma-arc torch for welding ducts in place Jun page 118 MFS-29701 Smaller coaxial-view welding larch Dec page 82 MFS-29744 TOROIDS Spacing windings evenly In toroidal inductors May page 69 NPO-17830 TORQUE CONVERTERS Torque-splitting gear drive Apr page,SO LEW-14908 TORQUEMETERS Noncontact measurements of torques In shafts Mar page 50 MFS-29717 Improved force-and-torque sensor assembly Sep page 95 NPO-17370 TORQUERS Servo reduces friction in flexure bearing Nov page 74 LAR-14349 TORSION Investigation of lapered tension/torsion strap Dec page 68 ARC-12480 TRAINING DEVICES Intelligenl computerized training syslem Oct page 107 MSC-2138t TRAJECTORIES Plaiting omital Irajectories for maneuvers Oct page 68 ARC-12365 TRANSFER FUNCTIONS Transfer functions via Laplace- and Fourier-Borel transforms Sep page 112 ARC-12295 TRANSFORMATIONS (MATHEMATICS) Transformations for atmospheric-radiation calculations Jul page 42 NPO-18026 TRANSIENT RESPONSE Calculating transient vibrations of coupled substruclures May pagp 54 MFS-28477 TRANSISTORS Doping to reduce base resistances 01 bipolar transistors May page 22 NPO-17948 Alternative Al,Ga, ,AS/GaAs translslors lor neural nelworks Sep page 26 NPO-18177 High-gain Al,Ga, ,AS/GaAs transistors for neural networks Sep page 24 NPO-18101 TRANSMISSIONS (MACHINE ELEMENTS) Computing lives and reliabililies of turboprop transmissions Mar page 44 LEW-14905 1MB S'I'IA'I'EGY FOR THE '90s A Conference for Rocky Mountain BASIC Users • CO'lPUTER AIDE~IEST • D:\TA ACQUlsrrim • I\STRU'lE~T CO\TROI. ~..I;.., ~-q{!,,~B)rHl cs ~B:\~ • 3D Solfo ~'fiRIN(; • RENDERING The Most Important Event of the Decade for HP BASIC Users. "HP and TransEra have revital· ized the RMB market for the '90s. This conference is a must for anyone who uses RMB." -Jim Bailey, conference organizer and noted RMB columnist. Organized by Ihe Inlernalional User Associalion. March 18-20, 1992 Long Bach, Calif. Cosponsored by Hewlett- Packard, TransEra, and TSA . Circle Reader Action No. 382 107 • For f •• t and' e.sY tubing chang~.· your .. ~ chQi'ce is eaSY. Eas~.LOad'" pump heac:ts open. -and Close with"the flip of a lever; Sirnply'turn , ·or·, a knob to a~just tubing occlusion: MasterflexlP UP- E~"sy-load purnplleadsmount directly to' Mastertlex lIP drives, ac;ceOt tile sarlle tubing, and .produce the lMIme floW rates (up to 13 liters/min) . as yOur .curtent Master'flex VP pump heads. Ydu.can : ..... stack several Ea~y-Load PU~P ~eads on a single. ,.' , .• , drille and change the ubing 10 one Easy-Lpad . ", " , without jotefrupting otf"~r pu'mp heads, Add ' 0 • Easy~t6;td to your Mast~rf1ex peristaltic syst~m toaay. Your chojc, Is eas..,.! of .- 0' of • :. , ,~ .. '. f. ',i. I .' . TRANSMITTER RECEIVERS Quad·port transceivers for a dual-CRR LAN Feb page 28 NPO·17541 TRANSONIC FLOW Transonic aeroelasticity analysis for helicopter rotor blade Jun page 60 ARC·12550 I Navier·Stokes simulation of , wind· tunnel flow Oct page 85 ARC·12193 Transonic flows about a fighter airplane Oct page 79 ARC·12304 Navier·Stokes computalions on zonal grids Dec page 71 ARC·12447 TRANSPIRATION Transpiration cooling of hypersonic blunl body Aug page 57 ARC·12383 TRANSPORT THEORY Computation of facilitated transport of 0, In hemoglobin Jun page 128 ARC·12417 TRAPPED PARTICLES Trapped·mercury·ion frequency standard Jun page 55 NPO·17456 TRENDS Estimating confidence in data via trend analysis Mar page 63 MFS·29710 TRIBOLOGY Ion processes modily lribological properties of surlaces Apr page 96 LEW·14865 TRUSSES Quick·connect truss fastener Jul page 84 MSC·21504 Quick·connecVdisconnect joint for lruss structures Sep page 102 MSC·21539 Dynamic analyses including joints of lruss structures Dec page 62 LAR-14306 Two techniques for suppressing vibrations in structures Dec page 60 NPO·17889 I TUBE HEAT EXCHANG· ERS Two-phase bidirectional heat exchanger Mar page 49 GSC·13287 TUNABLE LASERS Computer processing of tunable·diode-Iaser spectra May pat'S 28 NPO·180 19 Acousto-oplical fiHer can rapidly tune solid· state lasers Jun page 52 NPO·17891 .0 I" Stirling·cycle cooling for tunable diode laser Aug page 16 NPO·18045 ••• ;.Lo.d-JM CoIe"Parmer nsfrome~t Co, . • M.aterfl.x-a~ TM eolEt-Pa"1ler Instrum~nt'Co_ " .. , TURBINE BLADES Smoother turbine blades resist thermal shock beUer .. ..... ~. • .. *' ; ~ /. • • • : Cole-Parmer® , , (0Yi;le r -~I.,str~",e,nt ~ompany· " ....--l. '--'" 7425 ~ .. Qak Park Ave.! Cliicago, lL 606118 L..~ Pq rmel DIAL: 1-890-323-4340 or , • •• 1-'708-647-7800 FAX:.1:708-641-e,60 ' " ;. ,.0 • Cir~le Re_de~ Aetio,(No. ~38 • , . . • f .' I ' , , " Jul page 81 MFS·28472 TURBINE ENGINES Computing rotationaV vibrational dynamics of lumine engines Mar page 42 LEW·14770 1991 Annual Subject Index TURBINE PUMPS Model of bearing with hydrostatic damper Jan page 43 MFS·29654 Laser welding of contoured Ihln·wall housings Mar page 57 MFS·29653 Computing flow in a labyrinth seal Jun page 98 MFS·29682 Damping seals would help support lur1lopump rotor Aug page 77 MFS·27227 Dynamic tester for rotor seals and bearings Dec page 80 MFS·28493 TURBINES Simulation of flow In a tumine cascade Feb page 58 ARC'12551 Computation of flow in a tumine stage on a refined grid Nov page 90 ARC·12444 Two·phase Hero tumlne with curved nozzles Nov page 87 N PO·18059 TURBOMACHINERY Using muHiple grids to compute flows Mar page 37 ARC·12321 Low·leakage inlet swirl brake Oct page 74 MFS·29608 TURBOPROP ENGINES Computing lives and reliabilitles of tumoprop transmissions Mar page 44 LEW·14905 TURBOSHAFTS Computer simulation of a small turboshaft engine Mar page 55 ARC·12299 TURBULENCE Analysis of tumulence in a simple shear flow Apr page 84 NPO-17374 Mathemalical models of tumulence in hypersonic flow Dec page 67 ARC·12609 TURBULENT FLOW Algebraic model of tumulence for intemal flow Aug page 63 ARC·12544 Computed tumulenl flow in a tumaround duct Oct page 82 ARC·12552 Pressure fluctuations in simulated tumulent channel flow Oct page 80 ARC·12597 Direct finite-difference simulations of tumulent flow Dec page 76 ARC·12463 TURBULENT MIXING Three·dimensional structure of a mixing layer Nov page 79 ARC·12506 TWO BODY PROBLEM Jacobi·integral method for two·body problem May page 56 MSC·21623 u ULTRASONIC WAVE TRANSDUCERS Improved unrasonic lransducer for measuring cryogenic flow Nov page 78 MFS·29687 ULTRASONICS Ultrasonic device monttors fullness of the bladder Sep page 115 LAR·13689 Ultrasonic device would open pipe bombs Sep page 108 NPO·17951 ULTRAVIOLET DETECTORS GaAsP photodiodes as x·ray detectors Sep page 22 NPO·17849 ULTRAVIOLET RADIATION Broadband, achromatic Twyman·Green interterom· eter Oct page 38 NPO·17675 UREAS Trealing wastewater with immobilized enzymes Feb page 70 MFS·26090 URETHANES Reactive fluorescent dyes for urelhane coatings Oct page 44 NPO·18038 USER REQUIREMENTS YAMM-yet another menu manager Feb page 47 NPO·17769 v VACUUM Long·lived , replaceable low· pressure seals Sep page 98 MFS·28521 VACUUM CHAMBERS Penetrable IInear·gap pressure seal Jul page 70 LEW·14965 VACUUM DEPOSITION Deposition of diamondlike films by ECR microwave plasma Oct page 42 NPO·16094 Heavy,worfnl>uter aids delJOea- loon of boundaries In larmlands page 74 ARC12B05 IMAGING TECHNIQUES Gel-filled hoiders lor uhrasonk: transducers page 38 LAA-14027 INFERENCE EvWaIlal of _ IunctJons "" seatches among data page 77 NPO-18113 INF1.ATABLE STRUCTURES Rapdy~ endosure page 58 MF5-28512 INFORMATlON THEORY E\l8lua1ion of Ihteshold hn:Iions "" searches among data page 77 NPO-18113 INJECTORS Orifices "" f\Je\-r." coo\- '"II of c:artlusloon chamber page .. NPO-1B22S INSULATlON Ceramoc>Ibous-tnSlJla1oon lherctecloon system page 4B ARC 11888 IRON ALLOYS tn,:l<>ase aI\oy page 69 MF5-28503 J JOINTS (JUNCTIONS) C<:>nl>ut'"ll large-angle transtents In structures page 54 LAA-14382 Higllilressure lead- Ihtough joInl ""9" 69 MFS-28404 JOULE-THOMSON EFFECT .JouIIH1lomson cooler prOOJces nearly coostanl temperature page 42 NPO-18184 AER==:)t-~ AEROSPACE CONTRACT MANUFACTURERS Where Buyers Have it Made! February 19, 20 & 21, 1992 Long Beach Convention Center, Long Beach, California SERVING: Air Transport, Space, Military, Ground Support, Civil Aviation, InteriorlExterior Furnishings & Supplies, Overhaul & Maintenance and Avionics. EXHmuoRS Aerospace-qualified job shops and contract manufacturers with expert capabilities in A .. ionics, Metal Working, Plastics, Composites, Rubber and suppliers of Components, Parts, Test Equipment and Materials. FOR INFORMATION TO EXHIBIT OR ATTEND FAX 1-313-643-0856 or CALL 1-800-635-9885. r - - - - -*Co~'!!!:!1'!!:Y !i£.ke..!!.~ I.!!!!eJ2r.9!!a!!!l~~d~._ - - - - , I CMEIAEROCON 92 Dexhibit Dattend I I NAME I I COMPANY I I I IADDRESS I I CITY. STAlE. ZIP I I PHONE & FAX I L ________________________ J 114 Circle Reader Action No. 636 L lANDSAT SATEUITES Assessmert of ec- curaaes d remote- """""'II"""", page 78 ARC 12371 lASER APPUCATlONS bmographIc measure- ~ of Iase<-bored holes page 68 MF5-29770 LEVITATION Acoustic "'""""'ement of periodic moIlon of levllaled obtec1 page 58 NPO-18191 UNEAR PROGRAMMING Merud-.-, soI\Ier of lneariJlO!jrarmwlg probtems page S7 LEW-14978 UOUID OXVllEN lutlflCalll "" use In liquid - page 61 MF5-29760 LUBRICANTS l.utlfican1 "" use In liquid - page 61 MFS-29760 M MAPS Assessment of ac- curacies of remoce- sensing """'" page 78 AAC-12371 Moled warm-worlting process "" an Iron-base alloy page 69 MF5-28503 MODULATION Resolution of pilose am- biguities In OPSK page 28 NPO-l8083 MONITORS Monttoring subsyslem lor lestlng bearings page 24 GSC-13432 MOTORS MonHoring subsystem lor lesllng bearings page 24 GSC-13432 N NAVIER-STOKES EQUATION 'blex-lllob sioolallon of twodmensionaJ lIows page 54 ARCl2810 NEURAL NETS Evaluallon of Ihreshold functions for searches among data page 77 NPO-18113 o OCEANOGRAPHY MalyzJng satellite images of \he ocean page 52 GSC-1332O ORBITAL UFETlME LOP-Iong-term orbI1 preactcr page 58 NPO-17052 ORJACES OnflC8S "" f\Je\-lim c0o\- Ing of c:artlusllon chafrber page 44 NPO-1B22S OSClLLATlONS AcousIlC measurement of penodic moIlon Q levltaled obtec1 page 58 NPO-18191 OXIDIZERS RI1enun-IciI witness cyIir-. page 44 NPO-1B224 p PHASE SHIFT KEYING ResoMoon of phase am- biguHIOS In OPSK page 28 NPO-l8083 PHOTOYOL1A1C CELLS Flexible, thin-lilm soIar- cell bIankeI page 20 NPO-18196 PlASMA ARC WELDING Gas contaminatm in pIasma-arc-_ atumirun page 73 MF5-27233 PLOTTING P\o(tlng program "" aerodynamical comp>Jtalions page 55 ARC12751 PREFLIGHT OPERATIONS Automatic generaUon of countdoMl-simuialing soIIware page 56 MF5-26091 PRESSURE VESSELS Higl>i>fessure lead- through joint page 69 MF5-28404 PROTECTIVE COATINGS Ceramic·lbous-insuJa11on lIlermaI-protection syslem page 4B ARCll888 PROTECTORS RapIdly dep\cr'(abIe enclosure page 58 MF5-28512 PUMPS AoIordynamic behavior 01 sawtooth-pattern damping seals page 63 MF5-27242 R RADlATlON MEASURING INSTRUMENTS ~Schlierenligllt meier page 23 LAA-14249 RADII Gauge measures large spIlerlcal bearing surfaces page 62 KSC-11485 REFRIGERATORS Joute4"l1omson cooler produces nearly coostanl temperature page 42 NPO-18184 REUABIUTY ANALYSIS Faull-tree Canern da~ seals page 63 MF5-27242 SEMICONOUCTOR DEVICES ~ charge-coupled device page 16 NPO 17855 SEMICONDUCTOR LASERS DoubIe-current-confined CSP laser page 22 LAR·14200 SIGNAL DETECTION ResoIutOO of phase am· biguities in OPSK page 28 NPO-18Ofl3 SOFTWARE ENGINEERING VOUS software facilitales development of other software page 74 ARCI2571 SOLAR BLANKETS FIexbIe, thin-film solar· cell blanket page 20 NP018196 SOLID STATE DEVICES ~ charge-<:oupled device page 16 NPOI7855 SPACE COMMUNICATION DoubI&-current-oonfined CSP laser page 22 LAR·14200 SPACECRAFT ORBITS LOP-Iong·teml orbit predictor page 56 NP017052 SPACECRAFT STRUCTURES Mewing and working on space structures page 73 MSC21556 SPECKLE HOLOGRAPHY Otgital correlatIOn In laser·speckle velocimetry page 40 MF5-26122 STRAPS Rillbon cable strap partly free 01 backlash page 60 GSC-t3371 STRUCTURAL VIBRATION More about nonobStruc· tM! panICle da~ page 63 MF5-29752 SUPERCONDUCTORS Measuring thermal dif· fusivity of a hlglHc superconOOctot page 34 GSC-13392 Noncontac1 measure- ment 01 criUcat current in superconcLoctor page 32 NPO 18255 SUPERCOMPUTERS SUpercomputers of the future page 78 ARC12416 SUPERSONIC FIDW Program solves Euler equatklns of supersonic flow page 56 lAR-14228 SUPERSONIC TRANSPORTS Cblique-fIying-wing super. sonic Iransport airplane page 66 ARC 12525 SWITCHES Thln-me

NASA Tech Briefs, January 1992

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