Van der Pauw measurement of metal fibre orientation in a plastic-metal composite

Stainless steel fibres in ABS plastic form a composite with an anisotropic resistivity. Samples are rectangular shapes with uniform thickness. By assuming two principal resistivities and by using van der Pauw's technique, we find ² = _{x y} . For rectangular samples, field theory determines _y / _x and hence fibre direction. Results for three sample geometries agree with the theoretical predictions of the fibre patterns and with X-ray data. Samples formed by a centre-sprue feed are the best for fabricating large, uniform samples, while samples with a large length-to-width ratio have the most uniform metal density and fibre orientation. Resistivity was also measured by the more-common two-probe technique. Results correlate well to van der Pauw data, with 95% confidence.     

The Advice and Influence Networks of Transformational Leaders.

Existing transformational leadership research has focused primarily on the behaviors of leaders and their effects on followers. The authors extended this research by examining the social networks of managers who exhibit transformational leadership behaviors. Their focus was on the network of relationships that managers develop and whether they hold key positions in the organization's informal social networks. In a field study using data from 39 managers and 130 nonmanagement employees of 6 organizations, the authors found that managers who score higher on transformational leadership tend to hold more central positions in organizational advice and influence networks. Furthermore, the direct reports of these leaders were also more central in informal organizational networks. These results illuminate one of the ways that managers who exhibit transformational leadership behaviors may exert influence in organizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The growth of (InGa)As quantum wells on GaAs(111)A, (211)A and (311)A substrates

The ability to grow high quality (InGa)As on the (111)A surface is essential for the production of a wide range of optoelectronic devices, but the topic has so far received little attention. What work there has been shows it to be highly problematic, reflected in the very broad photoluminescence (PL) peaks observed for GaAs:(InGa)As multiple quantum well structures. The origin of this broadening is unclear but is certainly related to the difficulty in choosing appropriate conditions for the growth of III-Vs on the (111)A surface. We have undertaken a study of the growth of (InGa)As on the GaAs(111)A, (211)A and (311)A surfaces with the goal of achieving high quality quantum well structures, the test being the ability to obtain narrow PL line widths. We have demonstrated that 80 Å 15% InGaAs(111)A single quantum wells with 12K PL peak widths of less than 8 meV can be obtained by growth at 400°C under a V:III ratio of 5:1.     

Magnetotransport of two-dimensional electron gas in Si/SiGe modulation doped structures grown by gas source molecular beam epitaxy

We have characterized two-dimensional electron gases (2DEGs) in Si/SiGe modulation doped structures grown by gas source molecular beam epitaxy. Hall bar structures were fabricated to characterize the structures and magnetotransport measurements were carried out at temperatures down to 0.4 K. Pronounced Shubnikov-de Haas oscillations were observed in the longitudinal magnetoresistance, indicative of high quality 2DEG in the channel. Electron mobilities up to 87,000 cm² V⁻¹ s⁻¹ with sheet densities about 7 × 10¹¹ cm⁻² were obtained at low temperature. Dingle plots of the magnetoresistance vs reciprocal magnetic field were utilized to determine the single-particle relaxation times in order to investigate scattering mechanisms in these structure. The ratio of the transport scattering time derived from electron mobility to the single-particle relaxation time is of the order of 10, indicating that remote impurity scattering is a dominant factor limiting the mobility of our structures. The behaviour of the magnetotransport data is discussed using a model for parallel conduction.     

Automatic dispensing of dichlorvos to control Ephestia kuehniella Zell. (Lepidoptera: Phycitidae) in flour mills

Dichlorvos applied weekly at the rate of 14.0 μg/l gave good control of Ephestia kuehniella in a flour mill. Other insects were also controlled. The insecticide was dispensed automatically by electrically operated sprayers when the mill was unoccupied. Exposure of test insects and chemical determinations of atmospheric concentrations showed that good distribution of vapour was obtained. Concentrations of dichlorvos were at a safe level for working well before the mill reopened after 8 hr. Contamination of flour was negligible. The method involves no disruption of routine working and there is no vapour hazard to workers.     

Sex discrimination counseling.

Presents a comprehensive discussion of the problems of women who actively challenge sex discrimination in their work and in consequence face lonely, expensive, and emotionally trying experiences. The steps by which a woman reaches the point of active protest, the institutional responses she may meet, and the countermoves open to her, are described. Special attention is given to the attitudes of unions, to legislation and the conduct of legal suits, to the type of support needed from a personal counselor during the stages of the discrimination action,and to the special problems of Black women, who are in double jeopardy, from racism and sexism. Numerous practical strategies are suggested. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aberrant left pulmonary artery presenting as a right paratracheal mass in an adult

Aberrant left pulmonary artery, or pulmonary sling, is a rare variation of the pulmonary vasculature, with only one previous report of the condition being recognized in an adult. In this report a second case recognized de novo in an adult is presented. Both of these adults were evaluated because of right paratracheal masses which required differentiation from pulmonary malignancies. The barium swallow shows a characteristic indentation of the anterior esophageal wall and the lateral tomogram demonstrates absence of the left pulmonary artery from its normal position in the left hilum. The pulmonary arteriogram is diagnostic and allows avoidance of more invasive diagnostic measures.     

Wheat-Legume Composite Flour Quality

Wheat-legume composite flours were produced by blending Canada Western Extra Strong (CWES) and Canada Western Red Spring (CWRS) wheat with varying amounts of three legume proteins. Legume protein addition produced breads with lower specific loaf volume, coarser crumb and firmer texture, and cooked white-salted noodles with greater compression stress and less cutting stress than the wheat controls. The CWES wheat compensated for the negative baking effects of the legume proteins as much as the CWRS wheat. End-use quality did not change at 2% soybean protein addition. Yellow pea protein produced the greatest quality changes, followed by chickpea and soybean protein.     

Salmonella spp. shedding by alberta beef cattle and the detection of Salmonella spp. in ground beef

Breeder cows, cattle recently arrived at feedlots, and cattle about to be shipped for slaughter were tested for Salmonella spp. No Salmonella spp. were detected in fecal samples from breeding cows. Nineteen of 1,000 (1.9%) fecal samples from recently arrived feedlot cattle were positive for Salmonella spp. compared to only 2 of 1,000 (0.2%) fecal samples taken within 2 weeks of slaughter. The positive fecal samples were collected in 5 of 50 (10%) "recent arrival" pens tested and in 1 of 50 (2%) pens tested within 2 weeks of slaughter. The serotypes isolated were Salmonella Agona, Salmonella Enteritidis, Salmonella Typhimurium DT104, and Salmonella 4,5,12:i:-. Ground beef samples purchased from retail outlets throughout Alberta were processed for Salmonella spp. Thirteen of 1,002 (1.3%) samples were positive for Salmonella spp. The serotypes isolated from ground beef were Salmonella Anatum, Salmonella Heidelberg, Salmonella Montevideo, Salmonella Typhimurium, Salmonella Typhimurium var. Copenhagen, and Salmonella Rough-O:i:1,2. The antibiotic resistance and pulsed-field electrophoresis gel macrorestriction patterns of all isolates were compared.