1,494 research outputs found
Guidelines for fabrication of hybrid microcircuits
Document is summary of approaches that may be taken in designing hybrid microcircuits similar to those for aerospace application
Preferences for accounting standards: The use of discriminant analysis in forecasting corporate manager lobbying behavior
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Wellness programs in police departments and how they effect workers\u27 compensation claims
Autographic determination of thermally-induced linear changes in ceramic bodies
The determination of changes in length of ceramic compositions as a function of temperature is frequently required in ceramic research and testing. With the use of an observer, excellent means are available for determination of changes in length over moderate ranges of temperature. However, the extended period required for some tests makes desirable the automatic recording of length change as a function of temperature.
There has been in use in the Ceramic Engineering Department a furnace arranged for determination of length changes; this furnace, shown in Figure 1, is so arranged that change in sample length causes linear displacement of a refractory rod in contact with the test piece.
The temperature of this furnace is determined in the usual way by use of either a thermocouple or a radiation pyrometer.
For the purpose of recording changes in one variable as a function of another, there is available a Leeds and Northrup X-Y Recorder. This instrument consists of two self-balancing potentiometers so connected that change in one measured voltage moves a recording pen in a horizontal direction, while the other produces a vertical motion of the recording chart, thus recording one voltage as a function of the other.
The problem of this work has been to design and construct a device to permit the use of the X-Y Recorder for obtaining, automatically, a plot of change in length as a function of temperature, using the existing furnace and a standard thermocouple or radiation pyrometer for temperature-voltage conversion --Introduction, page 1
The Distribution of Fishes in the Little Tennessee River System
This paper is the product of a study of the ichthyofaunal distribution within the Little Tennessee River. This system is a major tributary to the Tennessee River.
A total of 212 collections are included in this paper. Of this total, 67 were made by the author. The remainder of the collections were made by various agencies and individuals. Of the total number of collections made by the author, approximately half were done using diving gear and employing sight identification. The remaining collections were accomplished with the aid of seines.
Included in this paper is a list of the species of fish which inhabit the river system with a description of habitat preferences and distributions within the system.
Also included is a discussion of the various ichthyofaunal units which exist in the system and the species which characterize each unit. The effects of alteration of the river system by man as shown by broken distributional patterns and species diversity is discussed
Conceptual design studies of candidate V/STOL lift fan commercial short haul transport for 1980 - 1985 V/STOL lift fan study
Conceptual designs of V/STOL lift fan commercial short haul transport aircraft for the 1980-85 time period were studied to determine their technical and economic feasibility. The engine concepts included both integral and remote fans. The scope of the study included definition of the hover control concept for each propulsion system, aircraft design, aircraft mass properties, cruise performance, noise and ride qualities evaluation. Economic evaluating was also studied on a basis of direct operating costs and route structure
Effect of sound stress on ovulation, estrus, and conception in beef heifers
Thirty of the 50 heifers used in estrous synchronization studies and that received prostaglandin and Syncro-Mate B to synchronize estrus were subjected to sound stress for 48 hours after prostaglandin was injected. Fifty-nine percent of 29 sound-stressed heifers that showed estrus within 5 days conceived when artificially inseminated compared with 72 percent of 18 nonstressed heifers
An Allosteric Mechanism for Inhibiting HIV-1 Integrase with a Small Molecule
HIV-1 integrase (IN) is a validated target for developing antiretroviral inhibitors. Using affinity acetylation and mass spectrometric (MS) analysis, we previously identified a tetra-acetylated inhibitor (2E)-3-[3,4-bis(acetoxy)phenyl]-2-propenoate-N-[(2E)-3-[3,4-bis(acetyloxy)phenyl]-1-oxo-2-propenyl]-L-serine methyl ester; compound 1] that selectively modified Lys173 at the IN dimer interface. Here we extend our efforts to dissect the mechanism of inhibition and structural features that are important for the selective binding of compound 1. Using a subunit exchange assay, we found that the inhibitor strongly modulates dynamic interactions between IN subunits. Restricting such interactions does not directly interfere with IN binding to DNA substrates or cellular cofactor lens epithelium-derived growth factor, but it compromises the formation of the fully functional nucleoprotein complex. Studies comparing compound 1 with a structurally related IN inhibitor, the tetra-acetylated-chicoric acid derivative (2R,3R)-2,3-bis[[(2E)-3-[3,4-bis(acetyloxy)phenyl]-1-oxo-2-propen-1-yl]oxy]-butanedioic acid (compound 2), indicated striking mechanistic differences between these agents. The structures of the two inhibitors differ only in their central linker regions, with compounds 1 and 2 containing a single methyl ester group and two carboxylic acids, respectively. MS experiments highlighted the importance of these structural differences for selective binding of compound 1 to the IN dimer interface. Moreover, molecular modeling of compound 1 complexed to IN identified a potential inhibitor binding cavity and provided structural clues regarding a possible role of the central methyl ester group in establishing an extensive hydrogen bonding network with both interacting subunits. The proposed mechanism of action and binding site for the small-molecule inhibitor identified in the present study provide an attractive venue for developing allosteric inhibitors of HIV-1 IN
Scheduling a three supply ship replenishment operation.
The operation of replenishment at sea is investigated for three
supply ships and L combatants using queueing theory concepts and a
random walk model in three dimensions. The distribution for total
replenishment time given the initial number of combatants to be
replenished by each supply ship and a specified cyclic order of
replenishment is expressed in terms of its Laplace transform under
the assumption of independent, exponential service times for each
supply vessel. A method for counting all possible sequences of
replenishment is not found, but some preliminary counting techniques
are developed which may be useful in its eventual determination.http://www.archive.org/details/schedulingthrees00huliLieutenant, United States NavyApproved for public release; distribution is unlimited
The kinematics of the bi-lobal supernova remnant G 65.3+5.7 - Paper II
Further deep, narrow-band images in the light of [O III] 5007 A have been
added to the previous mosaic of the faint galactic supernova remnant G
65.3+5.7. Additionally longslit spatially resolved [O III] 5007 A line profiles
have been obtained at sample positions using the Manchester Echelle
Spectrometer at the San Pedro Martir observatory. The remnant is shown to be
predominantly bi-lobal with an EW axis for this structure. However, a faint
additional northern lobe has now been revealed.
Splitting of the profiles along the slit lengths, when extrapolated to the
remnant's centre, although uncertain suggests that the expansion velocity of
this remnant is between 124 and 187 km/s ie much lower than the 400 km/s
previously predicted for the forward shock velocity from the X-ray emission.
An expansion proper motion measurement of 2.1+-0.4 arcsec in 48 years for the
remnant's filamentary edge in the light of Halpha+[N II] has also been made.
When combined with an expansion velocity of ~155 km/s, a distance of ~800 pc to
G 65.3+5.7 is derived.
Several possibilities are considered for the large difference in the
expansion velocity measured here and the 400 km/s shock velocity required to
generate the X-ray emission. It is also suggested that the morphology of the
remnant may be created by a tilt in the galactic magnetic field in this
vicinity.Comment: 10 pages, 5 figures, accepted for publication in A&
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