Improvement of chemical vapor deposition process for production of large diameter carbon base monofilaments

Research was conducted to develop large diameter carbon monofilament, containing 25 to 35 mole % element boron, in the 2.0 to 10.0 mil diameter range using the chemical vapor deposition process. The objective of the program was to gain an understanding of the critical process variables and their effect on fiber properties. Synthesis equipment was modified to allow these variables to be studied. Improved control of synthesis variables permitted reduction in scatter of properties of the monofilaments. Monofilaments have been synthesized in the 3.0 to nearly 6.0 mil diameter range having measured values up to 552,000 psi for ultimate tensile strength and up to 30 million psi for elastic modulus

Improving stress coping ability: comparison between the CYP17 genotype Of Ovis Aries and Capra Hircus

The ability of animals to adapt to stress is not only an animal health and welfare concern, but also influences reproduction potential and robustness. An important pathway involved in the stress response is the hypothalamic-pituitary-adrenal axis (HPAA) that results in the release of cortisol from the adrenal gland. In this study the cortisol responses of South African Merinos were measured to assess HPAA responsiveness to stress and relate it to behavioural stress responses to flock-isolation. The experiment was structured according to a 2×2 statistical design, with CYP17 genotype (WT1/WT1 vs. WT1/WT2) and selection line (H-line vs. L-line) as factors. Selection line criteria was based on divergent selection for (H-line) or against (L-line) maternal multiple rearing ability, where the H-line generally outperformed the L-line in terms of reproduction, animal welfare and resistance to certain pathogens. The CYP17 genotype is involved in the biosynthesis pathway of cortisol. In the present study the CYP17 genotype showed a significant influence on behavioural stress responses, where three parameters of the flock-isolation test were affected (P<0.05), namely the number of bleats uttered, the urinating frequency and the average distance from a human operator. It is suggested that the CYP17 genotype affects behavioural responses via its effects on cortisol production, and that the SNPs located within the CYP17 genotype may have application in marker-assisted selection of sheep

Further development of chemical vapor deposition process for production of large diameter carbon-base monofilaments

The development of large diameter carbon-base monofilament in the 50 micron to 250 micron diameter range using the chemical vapor deposition process is described. The object of this program was to determine the critical process variables which control monofilament strength, monofilament modulus, and monofilament diameter. It was confirmed that wide scatter in the carbon substrate strength is primarily responsible for the scatter in the monofilament strength. It was also shown through etching experiments that defective substrate surface conditions which can induce low strength modular growth in the monofilament layers are best controlled by processing improvements during the synthesis of the substrate. Modulus was found to be linearily proportional to monofilament boron content. Filament modulus was increased to above 27.8MN/sq cm but only by a considerable increase in monofilament boron content to 60 wt. % or more. Monofilament diameter depended upon dwell time in the synthesis apparatus. A monofilament was prepared using these findings which had the combined properties of a mean U.T.S. of 398,000 N/sq cm, a modulus of 18.9 MN/sq cm (24,000,000 psi), and a diameter of 145 microns. Highest measured strength for this fiber was 451,000 N/sq cm (645,000 psi)

Source parameters of the 23 April 1992 M 6.1 Joshua Tree, California, earthquake and its aftershocks: Empirical Green's function analysis of GEOS and TERRAscope data

Source parameters of the M 6.1 23 April 1992 Joshua Tree mainshock and 86 M 1.8 to 4.9 aftershocks are determined using an empirical Green's function methodology. For the aftershocks, deconvolved P- and S-wave spectra are calculated for 126 pairs of closely spaced events recorded on portable GEOS stations; S-wave spectra from the two horizontal components are averaged. The deconvolved spectra are fit by a ratio of omega-square source models, yielding an optimal (least-squares) corner frequency for both the large and the small event in each pair. We find no resolved difference between the inferred P- and S-wave corner frequencies. Using the standard Brune model for stress drop, we also find no resolved nonconstant scaling of stress drop with moment, although we also conclude that detailed scaling systematics would be difficult to resolve. In particular, a weak increase of stress drop with moment over a limited moment/magnitude cannot be ruled out. For magnitudes smaller than M 3 to 3.5, the inferred stress-drop values will be limited by the maximum observable corner frequency value of 60 Hz. For the mainshock, source-time functions are obtained from mainshock recordings at three TERRAscope stations (PFO, PAS, and GSC) using an M 4.3 foreshock as an empirical Green's function. The results indicate a fairly simple, single-pulse source-time function, with clear south-to-north directivity and an inferred rupture radius of 5 to 6 km. The deconvolved source-time functions are inverted to obtain a finite-rupture model that gives a robust estimate of rupture dimension. Early aftershocks are found to lie along the perimeters of regions with high mainshock slip. The inferred mainshock stress-drop value, 56 bars, is within the range determined for the aftershocks. Our derived mainshock source spectra do not show resolvable deviation from the omega-square model

Researching trust in the police and trust in justice: a UK perspective

This paper describes the immediate and more distant origins of a programme of comparative research that is examining cross-national variations in public trust in justice and in the police. The programme is built around a module of the fifth European Social Survey, and evolved from a study funded by the European Commission. The paper describes the conceptual framework within which we are operating – developed in large measure from theories of procedural justice. It reviews some of the methodological issues raised by the use of sample surveys to research issues of public trust in the police, public perceptions of institutional legitimacy and compliance with the law. Finally it gives a flavour of some of the early findings emerging from the programme