Boundary Counterterms and the Thermodynamics of 2-D Black Holes

We utilize a novel method to study the thermodynamics of two dimensional type 0A black holes with constant RR flux. Our approach is based on the Hamilton-Jacobi method of deriving boundary counterterms. We demonstrate this approach by recovering the standard results for a well understood example, Witten's black hole. Between this example and the 0A black hole we find universal expressions for the entropy and black hole mass, as well as the infra-red divergence of the partition function. As a non-trivial check of our results we verify the first law of thermodynamics for these systems. Our results for the mass disagree with the predictions of a proposed matrix model dual of the 0A black hole.Comment: 27 pages, uses utarticle.cls; corrected typos and added reference

Genetic Recombination in Bacteriophage {varphi}X174

Genetic recombination in bacteriophage {varphi}X174 usually takes place early in the infection process and involves two parental replicative form (double-stranded) DNA molecules. The host recA protein is required; none of the nine known {varphi}X174 cistron products is essential. The products of a single recombination event are nonreciprocal and asymmetric. Typically, only one of the parental genotypes and one recombinant genotype are recovered from a single cell. An alternative, less efficient recombination mechanism which requires an active {varphi}X174 cistron A protein is observed in the absence of the host recA gene product

Daze fasteners

A daze fastener system for connecting two or more structural elements wherein the structural elements and fastener parts have substantially different coefficient of thermal expansion physical property characteristics is employed in this invention. By providing frusto-conical abutting surfaces between the structural elements and fastener parts any differences in thermal expansion/contraction between the parts is translated to sliding motion and avoids deleterious thermal stresses in the connection. An essential feature for isotropic homogeneous material connections is that at least two sets of mating surfaces are required wherein each set of mating surfaces has line element extensions that pass through a common point

Split-set Rock Bolt Analysis

A system of twelve equations have been developed for the elastic-plastic analysis of split-set roof bolts and these equations have been programmed for solution on the IBM 370/168 computer. Typical solutions have been presented in graphical form for comparison with experimental data. The results compare favorably for most of the split-sets providing the system parameters are properly specified. It appears that this analytical solution will be valuable to mining engineers since the solutions have been put in graphical form. Plots of the effects of the various parameters (material strength, material strain-hardening, friction, thickness, radius, angle of contact) on the holding capacity of split-sets have been constructed and are presented in this paper. © 1979

A Family Enrichment Workshop to Enhance Communication Skills Among African-American Families at the Berean Seventh-day Adventist Church in Baton Rouge, Louisiana

Problem Research has established that healthy communication skills contribute to marital and family satisfaction among African-Americans. African-American families, in particular, are in need of communication skills and enhancement resources that address their specific ethnic and cultural dynamics. The Berean Seventh-day Adventist Church is a predominately African-American church located in the Belfair community of Baton Rouge, Louisiana. Currently the Seventh-day Adventist Church does not provide any researched family enrichment resources that address the specific dynamics of African-American Seventh-day Adventist families, which makes it necessary for research, resources, and programs to be developed that assist Seventh-day Adventist African-American families with healthy communication skills to produce greater family satisfaction. Method The African-American families of the Berean Seventh-day Adventist Church were selected for investigation of improvement of healthy communication skills. Research was conducted and a family communication enrichment seminar was tested as a means of providing the African-American families of the Berean Seventh-day Adventist Church with resources to improve family communication skills. The program was comprised of the following: 1. A review of the extant literature was conducted to identify the relevant components to be addressed in the program. 2. A six-week pre-seminar sermon series was presented that taught the biblical principles of healthy family communication. 3. A survey evaluating the effectiveness of the six-week pre-seminar sermon series was administered. 4. A baseline family communication assessment inventory was administered to establish a benchmark of participants’ current use of positive communication skills. 5. A one-day, three-part family communication seminar designed to teach healthy family communication techniques was presented. 6. A survey evaluating the effectiveness of the family communication enrichment seminar was administered. 7. An exit family communication assessment inventory was administered to collect data for comparison to the baseline. 8. The data was evaluated, conclusions were made, and recommendations were suggested. Results Survey results indicated that participants benefited from the six-week sermon series and also viewed the seminar as beneficial to their understanding of positive family communication. Analysis of the pre- and post-family communication seminar intervention indicated a slight increase of respondents reporting positive family communication between pre and post-seminar assessment inventories. Of the 39 results 20 showed an increase, with seven being statistically significant. Of the 39 results 19 showed a decrease, with six being statistically significant. Statistically significant improvements were made in the areas assessing communication frequency, communication avoidance, and the quality of family of communication. Conclusions Five recommendations emerged as a result of this project: a) Replicate research using a larger sample size (100 or more samples) and multiple interventions; b) In the future, allow a longer period of time between assessments to allow participants a greater opportunity to internalize the information presented during pre-sermon series and seminar; c) In the future, have trained surveyors administer inventories; d) In the future, design an inventory to assess family communication that is culturally sensitive to African-American families; e) In the future, include in each component of the program all family members (i.e., children, other adults) of the household, and have them complete pre and post-intervention assessments

Cryogenic Insulation System

This invention relates to reusable, low density, high temperature cryogenic foam insulation systems and the process for their manufacture. A pacing technology for liquid hydrogen fueled, high speed aircraft is the development of a fully reusable, flight weight cryogenic insulation system for propellant tank structures. In the invention cryogenic foam insulation is adhesively bonded to the outer wall of the fuel tank structure. The cryogenic insulation consists of square sheets fabricated from an array of abutting square blocks. Each block consists of a sheet of glass cloth adhesively bonded between two layers of polymethacrylimide foam. Each block is wrapped in a vapor impermeable membrane, such as Kapton(R) aluminum Kapton(R), to provide a vapor barrier. Very beneficial results can be obtained by employing the present invention in conjunction with fibrous insulation and an outer aeroshell, a hot fuselage structure with an internal thermal protection system

Computerized Physician Order Entry Systems: The Coming of Age for Outpatient Medicine

Davis discusses a new study in PLoS Medicine that evaluates the effectiveness of automated computerized alerts at reducing prescription errors in a primary care setting

Your Lawn

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Experimental study of the flow field inside a whirling annular seal

The flow field inside a whirling annular seal was measured using a 3-D Laser Doppler Anemometer (LDA) system. The seal investigated has a clearance of 1.27 mm, a length of 37.3 mm, and is mounted on a drive shaft with a 50 percent eccentricity ratio. This results in the rotor whirling at the same speed as the shaft rotation (whirl ratio = 1.0). The seal is operated at Reynolds number of 12,000 and a Taylor number of 6,300 (3,600 rpm). The 3-D LDA system is equipped with a rotary encoding system which is used to produce phase averaged measurements of the entire mean velocity vector field and Reynolds stress tensor field from 0.13 mm upstream to 0.13 mm downstream of the seal. The mean velocity field reveals a highly three dimensional flow field with large radial velocities near the inlet of the seal as well as a recirculation zone on the rotor surface. The location of maximum mean axial velocity migrates from the pressure side of the rotor at the inlet to the suction side at turbulence kinetic energy. However, turbulence production and dissipation attain equilibrium fairly quickly with remaining relatively constant over the last half of the seal

Turbulence measurements of high shear flow fields in a turbomachine seal configuration

The mean velocity and Reynolds stress tensor throughout a whirling annular seal are presented. The data was collected with a three dimensional laser Doppler velocimeter using phase averaging. Two axial flow conditions (Re = 12,000 and 24,000) were studied at one shaft speed (Ta = 6,600). The eccentricity and whirl ratios were 50 and 100 percent, respectively. There is a region of high axial momentum in this region is higher in the low Reynolds number case due to an axial recirculation zone that occurs on the suction side of the rotor at the inlet. The recirculation zone does not occur in the high Reynolds number case. At both Reynolds numbers, there is a recirculation zone on the rotor surface in the pressure side of the inlet. This recirculation zone extends from 20 to 200 degrees rotor zenith in the tangential direction, and is one third of a clearance wide radially. The high Reynolds number recirculation zone is 1.5 mean clearances long, while the low Reynolds number zone extends 2 mean clearances downstream. When compared to previous studies, it is apparent that the tangential momentum is no greater for a seal with whirl than for one without if other parameters are constant. Areas of high tangential momentum occur in the clearance where the axial momentum is low. Average exit plane tangential velocities in the high Reynolds number case are 1.5 times greater than those in the other flow case. These results are in general agreement with predictions made by other investigators