Transport properties of the organic conductor (TMTSF)2BrO4: Evidence of variable-range hopping

A study of d.c. and microwave conductivity and thermoelectric power of the organic conductor (TMTSF)₂BrO₄ is presented. The transport properties are in qualitative agreement with charge transport via variable-range hopping among localized states. The localization is attributed to the anions, which are ordered only over short ranges, probably due to impurities.     

Structure and electronic properties of bismuth anodic oxide films—I. Photoeffects

Estimates of the conduction electron mobility, lifetime and trap density of anodic bismuth oxide films, obtained by measuring the transient response of a polarized bismuth anode to an intense flash of white light, showed that the films had a highly defective structure. for thicker films (～240 nm) the photo-response arose from the production of electron-hole pairs in the bulk of the film, but for very thin films (～5 nm) the response arose from photo-emission of electrons from the metal into the film, and effects attributed to the decay of space charges of both electrons and mobile ions were observed.The photo-response was used to investigate the possible formation of films of bismuth oxo-halides under conditions in which these compounds were thermodynamically stable. Incorporation of iodide and bromide into the very thin films at pH 5 was detected. No effect of chloride was observed. Comparison with cyclic voltammetric results indicated that an anodic layer of bismuth oxoiodide might be formed by direct nucleation on to the metal surface.     

Failure experience of programmable logic controllers used in emergency shutdown systems

Microprocessor-based programmable logic controllers (PLCs) are often used in applications to safety shut down a process or facility if unsafe conditions are detected. Increased use of quantitative reliability analysis requires additional and more detailed failure rate estimates for analyzing PLCs. This technical note presents failure rates derived from PLC performance in emergency shutdown (ESD) systems for natural gas compressor stations. The PLCs analyzed operate with roughly 40 inputs processed through three input modules and generate approximately 20 control signals through two output modules. Failure rates range from 0·072/year when the PLC alone was considered to 0·32/year when all types of failures were considered. (All failures include effects that are not necessarily attributable to the PLC microprocessors, such as human errors while working in the PLC cabinets and failures of common power supplies.)     

Death certification by house officers and general practitioners--practice and performance

The objective of this study was to assess the knowledge, attitudes and behaviour of House Officers and General Practitioners (GPs) in relation to death certification, to determine the scope for future intervention. A postal questionnaire was used to survey all House Officers (174) and a 10 per cent random sample of GPs (131) in Mersey Region. The main outcome measures were: death certification experience; knowledge, attitudes and behaviour in relation to data uses and coding; and acceptability of Cause of Death statements. Response rates were comparable-119/174 House Officers (68.4 per cent) and 95/131 GPs (72.5 per cent). Most House Officers (78.8 per cent) and GPs (85.3 per cent) reported that they made the best possible Cause of Death statement but, respectively, 62.4 per cent and 59.3 per cent of these might modify a statement in some circumstances. Significantly more House Officers (70.3 per cent) than GPs (44.2 per cent) acknowledge room for improvement and were amenable to more training (86.6 per cent versus 52.5 per cent), but significantly fewer felt sufficiently instructed (23.7 per cent versus 52.6 per cent). Most respondents (> 90 per cent) considered accurate death certification important, but 46.2 per cent of House Officers had not read the death certificate book instructions. Knowledge was variable, especially concerning Underlying Cause of Death. Written Cause of Death statements were broadly similar in style and standard between groups. Experience did not appear to improve death certification practice. Better and co-ordinated undergraduate and early post-graduate education (which should be continuing and audited), and practical accessible guidance on death certificate completion, might improve standards of practice and performance within the existing framework. Alternative methods of presenting guidance on death certificate completion should be explored.     

Hepatitis B immunization and exposure to blood among surgical staff

A questionnaire was sent to all 158 staff of the operating department of a London teaching hospital to confirm their hepatitis B immunization status and establish the number of incidents involving exposure to blood during the preceding 4 weeks. Of these personnel, 104 (66 per cent) were known to be immune to hepatitis B either through immunization (97) or previous infection (seven). A further 23 (15 per cent) had completed a course of immunization but their seroconversion had not been checked. There were 26 sharps injuries sustained by 14 (12 per cent) of 119 staff and 240 other exposures to blood. Four of the sharps injuries had been reported. Staff known to be immune were more likely than those with unknown or negative immunity to report incidents (20 versus 0 per cent (95 per cent confidence interval of difference 2-38 per cent)). Doctors sustained more non-sharps exposures to blood than others (47 versus 23 per cent (95 per cent confidence interval of difference 7-40 per cent)). An important minority of operating department staff remains unimmunized against hepatitis B, although exposure to blood is common. Incidents are rarely reported and staff with unknown or negative immunity seem less likely to report than those known to be immune.     

AlGaInAs/InP double heterostructure lasers grown by low-pressuremetal organic vapour-phase epitaxy for emission at 1300 nm

Reports for the first time the growth and fabrication of laser diodes for emission near 1300 nm in the AlGaInAs/InP alloy system by low pressure metal organic vapour phase epitaxy (LP-MOVPE). Threshold current density was 4.8 kA/cm² with associated T₀ of 88°C in the range 7-60°C     

Frictional properties of metal-insulator interfaces

The energy by which a normal zone may be created in a cryostable composite superconductor derives almost exclusively from frictional heating, which originates from the movement of conductor against insulator. The magnitude of the frictional heat pulse depends on the mechanical properties of the winding, the frictional properties of the conductor-insulator interface, and the dynamics of the slip process. Quantification of the frictional heat pulse is presently under investigation; this paper presents preliminary results.     

Effect of glucose deprivation of GLUT 1 expression in 3T3-L1 adipocytes

Elevated glucose transport rates during glucose deprivation are phenomena that have been observed in several different types of cells in culture. We show here that glucose transport rates in 3T3-L1 adipocytes increased by 10-fold within 18 h in response to glucose deprivation, confirming earlier work by Van Putten and Krans (Van Putten, J. P. M., and Krans, H. M. J. (1985) J. Biol. Chem. 260, 7996-8001). Mannose and 3-O-methylglucose (a nonmetabolizable glucose analog), but not fructose or galactose, blocked the increase in transport activity. Although the increase in transport was dependent on new protein synthesis, only a small and transient increase in GLUT 1 mRNA (less than 2-fold) was observed. In addition, the level of the normal isoform of GLUT 1 (46 kDa) did not increase. A lower molecular mass isoform (37 kDa) was observed but not until 15 h after glucose removal, the appearance of which was clearly not correlated with the increase in activity. Further, the extracellular glucose concentration required to elicit accumulation of this form (p37) was 2 orders of magnitude less than that required for transport stimulation (5 microM versus 500 microM glucose; p37 accumulation and transport activation, respectively). Interestingly, p37 was seen in the presence of galactose, but not fructose, despite elevated transport activity with either sugar. The p37 isoform was slightly larger than N-glycosidase F-treated GLUT 1 (36 kDa), implying that this form is still glycosylated, albeit incompletely. It is not known if p37 is functional, but the time- and sugar-dependent appearance of the lower isoform suggests that p37 is not responsible for starvation-induced transport but potentially represents an underglycosylated precursor of the normal, 46-kDa isoform of GLUT 1.     

Recruitment sources and posthire outcomes for job applicants and new hires: A test of two hypotheses.

This study, unlike most recruitment source research, tested for and ruled out the contaminating effects of prescreening and self-selection bias by examining applicants and new hires for nursing positions (S. L. Rynes and A. E. Barber, 1990). Consistent with the predictions of A. Rees (1966) and J. C. Ullman (1966), recruitment sources reached differently qualified applicants in terms of nursing experience and education which, in turn, were valid predictors of subsequent nurse performance. In a similar manner, recruitment sources produced sharply different levels of prehire knowledge, which was inversely related to voluntary turnover after 1 yr. However, contrary to both hypotheses, prehire knowledge, education, and experience did not mediate the relationship between recruitment sources and posthire outcomes. Recruitment sources with greater prehire knowledge did not always result in lower voluntary turnover. Likewise, despite recruitment source differences in nursing experience and education, recruitment sources were not related to nursing performance. Finally, the extent to which applicants use multiple recruitment sources was investigated, and the methodological problem that this creates for recruitment source research was discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)