Study of microstructure in vanadium-palladium alloys by X-ray diffraction technique

Present study considers microstructural characterization of vanadium-based palladium (V-Pd) alloys, which are widely used in marine environment due to their high corrosion resistance. The X-ray diffraction line profile analysis (XRDLPA) have been used to assess the microstructure in body centred cubic (bcc) V-Pd alloys having four different nominal compositions in wt.%. X-ray diffraction line broadening analysis on V-Pd alloys has been performed by using different methods like the Warren-Averbach, double-Voigt and Rietveld methods. Finally microstructural defect parameters such as domain size (D), r.m.s. microstrain 〈ɛ ²〉^1/2, twin fault (β′), spacing fault (αɛ) and deformation stacking fault (α) were evaluated in these alloys by Fourier line shape analysis using Rietveld method in which the X-ray diffraction profiles of these alloys were described by the pseudo-Voigt function to fit the experimental data. From analysis it has been observed that twin fault, β′, and the spacing fault, αɛ, are totally absent in these bcc alloy systems because the twin fault, β′, has been observed to be either negative or very small (within experimental error limit) for these alloy systems and the spacing fault, αɛ, appears to be negative. This analysis also revealed that the deformation stacking fault, α, is significantly present in this alloy system and increases with Pd content.     

Inhibition of androgen action by dehydroepiandrosterone sulfotransferase transfected in PC-3 prostate cancer cells

Age-dependent loss of androgen sensitivity of the rat liver is associated with a marked increase in dehydroepiandrosterone/hydroxysteroid sulfotransferase (rStd) activity. Sulfonated steroid hormones are known to be ineffective in binding receptor proteins. These observations suggest that intracellular androgen sulfonation can physiologically influence androgen action. We have examined the inhibitory effect of rStd on androgen action in the human prostate cancer-derived PC-3 cells transfected with the rat androgen receptor (AR) expression plasmid and two androgen-responsive promoter reporter constructs (murine mammary tumor long-terminal repeat ligated to chloramphenicol acetyltransferase (CAT) gene and rat probasin androgen response element (ARE) ligated to firefly luciferase (LUC) gene). These transfected cells were dependent on 5alpha-dihydrotestosterone (DHT) for the activation of both reporter genes and showed about a 200- and a 800-fold increase of CAT and LUC activity, respectively, at 10(-10) M DHT over the no-hormone control. Expression of the sulfonating enzyme in this cell transfection system via the rStd expression plasmid caused a dose-dependent decline in the reporter activity with approximately 90% inhibition of androgen action at a rStd:AR plasmid ratio of 100. From these results we conclude that irrespective of a high level of AR, changes in the Std expression can markedly alter the androgen sensitivity of target cells.     

Contributions of the left and right cerebral hemispheres to line bisection

Thirty-one right-hemisphere lesioned (RHL) patients, 11 left-hemisphere lesioned patients (LHL) and 10 normal controls (NC) bisected lines in three spatial location and four directional cuing conditions. The error direction and error size were analyzed as separate and combined variables. Seventy-seven percent of RHL patients and 45% of LHL patients made abnormally large errors in line bisection. Right-hemisphere lesioned patients were more sensitive to spatial location and directional cuing than NC subjects. In contrast, LHL patients were less sensitive to either condition than NCs. The error direction and error size emerged as dissociable components of line bisection. Right-hemisphere lesioned patients and NC subjects bisected lines consistently to one side of the true center. Left-hemisphere lesioned patients bisected lines equally often on both sides of the true center. Both RHL and LHL patients made larger absolute bisection errors than NC subjects, but the RHL patient's errors were larger than those of the LHL patients. We propose that the greater sensitivity of RHL patients to spatial location and directional cues and the directional consistency of their bisection errors represent contributions of the intact left cerebral hemisphere to line bisection. In contrast, the LHL patient's unrestrained ability to orient to both ends of the line reflects a contribution of the intact right cerebral hemisphere to line bisection. The failure of both groups to accurately bisect lines reflects a common visuospatial processing deficit that is more pronounced following RHLs than LHLs.     

Evolution of federal and state policies for persons with disability in the United States: Efficiency and welfare impacts

This paper focuses on the labor force participation and earnings of the working age disabled in the United States, as they vary by gender, age, and minority status. Expenditure on public and private sector programs targeted to persons with disabilities exceed $100 billion for approximately 8m individuals. Program objectives are to increase employment opportunities among the disabled as well as, provide public assistance through various welfare provisions. This paper argues public policies and public expenditures have favored assistance and short run equity concerns relative to rehabilitation and vocational training, thus providing work disincentives to people with disabilities and undermining their long-term welfare.     

A novel technique for in-line monitoring of micro-contamination andprocess induced damage

The use of a simple, rapid and nondestructive technique for inline monitoring of electrically active impurities introduced during wafer fabrication is reported. This AC surface photovoltage-based technique can determine the substrate doping type, doping concentration, oxide charge, and energy distribution of interface traps on both bare and oxidized silicon wafers without the formation of gate electrodes and substrate contacts. The technique is shown to have good reproducibility and resolution for quantifying the electrically active impurities, on the order of 1×10¹⁰ q/cm². Detection of contaminants and static charges by this technique is shown to correlate well with the electrical performance of thin dielectrics. The use of this technique for inline monitoring of very low levels of plasma-induced damage in the SiO₂/Si system is also discussed as is the potential for this tool in reducing furnace downtimes and in prompt identification of the source of contamination     

Large-eddy simulation of laser-induced surface-tension-driven flow

The turbulent flow inside a laser-generated molten pool is investigated by an adapted large-eddy simulation (LES) model that incorporates physical considerations pertaining to the solid-liquid phase change. A single-domain, fixed-grid enthalpy-porosity approach is utilized to model the phase-change phenomena in the presence of a continuously evolving solid/liquid interface. The governing transport equations are simultaneously solved by employing a control-volume formulation, in conjunction with an appropriate enthalpy-updating closure scheme. To demonstrate the performance of the present model in the context of phase-change materials processing, simulation of a typical high-power laser melting process is carried out, where effects of turbulent transport can actually be realized. It is found that the present LES-based model is more successful in capturing the experimental trends, in comparison to the k-ε-based turbulence models often employed to solve similar problems in contemporary research investigations.     

Reliability bounds and other inequalities for discrete life distributions

In this paper we give sharp bounds on the reliability of discrete IFR, IFRA, NBU, DFR, DFRA and NWU classes, based on one known moment. Subsequently the discrete analogues of several continuous-time results related to maintained systems are also presented.