Arcjet flow properties determined from laser-induced fluorescence of atomic nitrogen

Flow property measurements that were recently acquired in the Ames Research Center Aerodynamic Heating Facility arcjet using two-photon laser-induced fluorescence (LIF) of atomic nitrogen (N) are reported. The flow properties, which include velocity, translational temperature, and N concentration, were measured simultaneously over a range of facility operating conditions for N(2)-argon test gas flows in the 30-cm-diameter nozzle. A recent measurement of the two-photon excitation cross section for the 3p(4)D degrees <-- 2p(4)S degrees transition of atomic nitrogen is used to convert the relative nitrogen concentration measurements to absolute values, and a nitrogen flow reactor is used to provide a room-temperature, reference-wavelength calibration of the translational temperature and velocity measurements. When combined with information from facility measurements, an analysis of the flow properties obtained using two-photon LIF of N yields the total free-stream flow enthalpy.     

The inverted repeat regions of the simian varicella virus and varicella-zoster virus genomes have a similar genetic organization

Simian varicella virus (SVV) causes a varicella-like disease in nonhuman primates. The DNA sequence and genetic organization of the inverted repeat region (RS) of the SVV genome was determined. The SVV RS is 7559 bp in size with 56% guanine+cytosine (G+C) content and includes 3 open reading frames (ORFs). The SVV RS1 ORF encodes a 1279 amino acid (aa) protein with 58 and 39% identity to the varicella-zoster virus (VZV) gene 62 and herpes simplex virus type 1 (HSV-1) ICP4 homologs, respectively. The predicted 261 aa SVV RS2 polypeptide possesses 52% identity with the VZV gene 63 homolog and 23% identity with the HSV-1 ICP22. The SVV RS3 encodes a 187 aa polypeptide with 56% and 28% identity to the VZV gene 64 and the HSV-1 US10 homologs, respectively, and includes an atypical zinc finger motif. A G+C-rich 16 base-pair (bp) sequence which is repeated 7 times and a putative SVV origin of replication were identified between the RS1 and RS2 ORFs. Comparison with the VZV RS indicates the SVV and VZV RS regions are similar in size and genetic organization.     

The relative efficacy of avoidant and nonavoidant coping strategies: A meta-analysis.

Conducted a series of meta-analyses, involving 43 studies, to ascertain whether there were systematic patterns in the empirical literature that described when attention strategies were more or less effective than avoidant strategies. Results of an overall analysis of studies providing tests of attention vs avoidance indicated little evidence for one strategy's superiority. However, supplementary analyses suggested there were boundary conditions that defined the relative efficacy of a specific strategy. Overall, avoidance was associated with more positive adaptation in the short-run. However, attention was superior to avoidance if the former involved a focus on sensory schemata rather than emotional processing. If attention involved an emotional interpretational set or no explicit set, then it was associated with more negative outcomes than avoidance. In terms of long-term outcomes, avoidance indicated better outcomes initially, but with time, attention was associated with more positive outcomes. A final set of analyses found that both attention and avoidance facilitated adaptation as compared with no instruction controls. The meta-analyses suggested the important role of interpretational set and whether one looks at the immediate or at the long-term effects of coping. (5 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Dorodnitsyn finite element formulation for turbulent boundary layers

The Dorodnitsyn boundary layer formulation is combined with a modified Galerkin finite element formulation and an implicit, non-iterative marching scheme to generate a computational algorithm that is both accurate and very economical. For four representative pressure gradient cases taken from the 1968 Stanford Turbulent Boundary Layer Conference the Dorodnitsyn finite element formulation is compared with a Dorodnitsyn spectral formulation and a representative finite difference package. All methods produce solutions of high accuracy but the Dorodnitsyn finite element formulation is about ten times more economical than the other methods.     

Hydrogen and oxygen from water—III evaluation of a hybrid process

A hybrid process, which simultaneously produces mechanical power and hydrogen and oxygen from water by the use of solar energy, is presented. The performance of the process is evaluated. Realistic constraints on the efficiencies of optical and mechanical components are used. A preliminary estimate of its economics is also presented.     

Temperature dependence of the strength-differential effect in hardened steels

The strength differential (SD) has been measured as a function of temperature in a fully hardened 0.2C, 6 Ni steel, quenched and then tempered at 250°C. It is found appropriate to express the results in terms of the intercept flow stresses as extrapolated back to zero plastic strain. The corresponding SD increases significantly with decreasing temperature below the ambient, and the data are well fitted by separating the SD into an athermal component (~3 pct) and a thermally activated component (up to ~15 pct at the liquid-nitrogen temperature). The latter type of contribution is thought to arise from a dilatation which occurs during the activation process for dislocation motion and which causes an increase in the activation energy under compressive loading and a decrease under tensile loading. The parameters obtained via this treatment are consistent with a double-kink Peierlsbarrier mechanism of plastic flow at low temperatures. This paper is based on a doctoral thesis presented in August 1972 by F. B. Fletcher to the Department of Metallurgy and Materials Science at the Massachusetts Institute of Technology.     

Survey of shell egg processing plant sanitation programs: effects on non-egg-contact surfaces

To successfully implement a hazard analysis critical control point plan, prerequisite programs are essential. Sanitation standard operating procedures are an important part of such a plan and can reduce contamination levels so that food safety and quality are not adversely affected. Noncontact surfaces in the shell egg processing plants can serve as a reservoir of cross-contamination. The objective of this study was to assess the efficacy of sanitation programs used in a variety of shell egg processing facilities (in-line, off-line, and mixed operations). Fourteen different noncontact surfaces were sampled in nine commercial facilities across the southeastern United States. Non-egg-contact surfaces were defined as those where the shell egg does not come into direct contact with the surface or with the fluid from that surface. Gauze pads soaked in sterile phosphate-buffered saline were used for sampling at the end of a processing day (POST) and again the next morning prior to operations (PRE). Aerobic plate counts (APCs) and numbers of Enterobacteriaceae were determined. No significant differences (P > 0.05) were found between POST and PRE counts for either population recovered from the 14 sampling sites. Only samples from the floor under the farm belts, nest-run loader, washers, and packer heads were reduced by 1 log CFU/ml of rinsate for APCs or Enterobacteriaceae counts. APCs of more than 10(4) CFU/ml of rinsate were recovered from many samples. Highest APCs were found on the floor under the farm belt and on shelves of the nest-run carts. High APCs were found on the wheel surface for off-line carts and on the loading dock floor. Highest Enterobacteriaceae counts were found in samples from the floor, drain, and nest-run egg cart shelves. A lack of significant difference between POST and PRE counts indicates that current sanitation programs could be improved. These data suggest that traffic patterns for the movement of eggs and materials through the plant should be reevaluated so that cross-contamination is reduced.