Race, class, and the attributional process.

Two experiments examined the process and content of attributional thinking in Black and White children who differed in socioeconomic status (SES). In Exp I, 171 7th graders subdivided into middle-SES Black, middle-SES White, low-SES Black, and low-SES White groups imagined that they succeeded or failed at an examination, with the cause of the outcome specified. Their perceptions of the dimensional properties of causes (locus, stability, and controllability), expectancy for success, teacher evaluation, and affective reactions were reported. Similar judgments were made in Exp II, with 148 of the Ss from Exp I, in response to actual rather than hypothetical success and failure, and Ss' causal attributions for their performance were reported. Analyses revealed that Blacks did not display a less adaptive attributional pattern than did Whites following actual performance, and no differences existed in Ss' understanding of the meaning (dimensional placement) of causes. A linkage between the locus of causes and affect also was documented in all race?×?SES groups. In contrast, race and class differences occurred in Ss' perceptions of predicted stability–expectancy and controllability–evaluation causal linkages. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Safety system logic solver availability, 1oo2D and TMR

Four simplifications in the calculation of safety instrumented system logic solver performance measures (mean time to failure and risk reduction factor) clarify the dependence on the various factors involved. These include failure rate, fail safe fraction, diagnostics coverage and common cause. Approximate MTTF and RRF formulas are developed for 1oo2D and TMR logic solvers. These provide an explicit indication of which factors have the greatest influence on improving safety.     

Green Catalysis with Alternative Feedstocks

The use of renewable feedstocks, derived from biomass, for the chemical industry is discussed. The modern chemical industry is based around platform chemicals, e.g. ethene, propene, benzene and xylenes, which are readily derived from oil, and using these intermediates a broad range of finished products can be derived. While it is feasible that biomass can be converted to syngas and hence to existing key platform chemicals, this loses all of the chemical complexity that is inherent in bio-derived molecules. In this paper some of the options are considered and, in particular, the oxidation of glucose and glycerol using gold nanoparticles supported on carbon is described. We also contrast the oxidation of glycerol using supported gold and gold–palladium alloys prepared using an impregnation technique, since the gold–palladium alloys have been shown to be highly effective for the oxidation of alcohols and the synthesis of hydrogen peroxide.     

Effect of Microstructure on the Radioluminescence and Transparency of Ce-Doped Strontium Hafnate Ceramics

In this paper we report on the fabrication and characterization of SrHfO(3):Ce ceramics. Powders were prepared by solid-state synthesis using metal oxides and carbonates. X-ray diffraction measurements showed that phase-pure SrHfO(3) is formed at 1200°C. Inductively coupled plasma spectroscopy confirmed the purity and composition of each batch. SrHfO(3) exhibits several phase changes in the solid, but this does not appear to be detrimental to the ceramics. Microprobe experiments showed uniform elemental grain composition, whereas aluminum added as charge compensation for trivalent cerium congregated at grain boundaries and triple points. Radioluminescence spectra revealed that the light yield decreases when the concentration of excess Sr increases. The decrease in the light yield may be related to the change of Ce(3+) into Ce(4+) ions. For stoichiometric SrHfO(3):Ce, the light yield is about four times that of bismuth germanate (BGO), the conventional benchmark, indicating great potential for many scintillator applications.     

Long wave motion in layered elastic media

Long wave motion in a geometrically symmetric 3-layer laminated elastic structure is investigated. The associated dispersion relation is established for three different boundary value problems. For all three cases, numerical solutions are presented and a long wave asymptotic analysis carried out, in each case the cut-off frequencies being shown to satisfy transcendental equations. Long wave approximations are employed to determine the asymptotic orders of the displacement components in the various long wave regimes. The asymptotic structures in a single layer plate associated with bending, extension, thickness stretch resonance and thickness shear resonance are well-known. It is shown that these structures are preserved within the multi-layer problem. This work provides the theoretical framework to generalise the above mentioned theories.     

Net generation or Digital Natives: Is there a distinct new generation entering university?

This article reports key findings from the first phase of a research project investigating Net generation age students as they encounter e-learning at five universities in England. We take a critical view of the idea of a distinct generation which has been described using various terms including Net generation and Digital Natives and explore age related differences amongst first year university students. The article draws on evidence from a survey of first year undergraduates studying a range of pure and applied subjects. Overall we found a complex picture amongst first-year students with the sample population appearing to be a collection of minorities. These included a small minority that made little use of some technologies and larger minorities that made extensive use of new technologies. Often the use of new technology was in ways that did not fully correspond with the expectations that arise from the Net generation and Digital Natives theses. The article concludes that whilst there are strong age related variations amongst the sample it is far to simplistic to describe young first-year students born after 1983 as a single generation. The authors find that the generation is not homogenous in its use and appreciation of new technologies and that there are significant variations amongst students that lie within the Net generation age band.     

Heterogeneous crystallization and composition dependence of optical parameters in Sn–Sb–Bi–Se chalcogenides

Bulk samples of Sn₁₀Sb_20−x Bi _x Se₇₀ (0 ≤ x ≤ 8) chalcogenide alloys were prepared by the conventional melt quenching technique. Thin films were prepared on well-cleaned glass substrates by thermal evaporation technique. X-ray diffraction studies revealed that the alloys with x = 0 and 2 at.% of Bi were amorphous, whereas the alloys with x = 4, 6, 8 at.% were crystalline. The crystalline phases are identified as due to the formation of Bi₂Se₃ and BiSe₂ phases. The microstructural and differential scanning calorimetric studies show the presence of these phases. A simple, straight forward procedure suggested by Swanepoel has been used to calculate the optical parameters, refractive index, and extinction coefficient. The optical gap for all the samples has been obtained from the Tauc plots. The variation in optical parameters for different Bi concentration has been explained on the basis of presence of defect states and the change in stoichiometry with the change in Bi concentration.