S and Te inter-diffusion in CdTe/CdS hetero junction

Effects of post formation thermal annealing of the CdTe–CdS device on the inter-diffusion of S and Te at the junction in a substrate configuration device have been studied by Auger electron spectroscopy. While the migration of S and Te atoms increases with annealing temperature, the extent of S diffusion is always higher than the diffusion of Te atoms. Inter-diffusion of S and Te causes the formation of CdTe_1-xS_x ternary compound at the CdTe–CdS interface.     

An EPR investigation of electrospun polyaniline-polyethylene oxide blends

The EPR magnetic susceptibility behavior of the camphorsulfonic acid doped polyaniline (PANCSA) blends with polyethylene oxide (PEO) is reported in fibers and films. In particular, EPR investigations on electrospun (PANCSA)_0.72(PEO)_0.28 nanofibers, cast films of (PANCSA)_0.72(PEO)_0.28 and cast films of (PANCSA) were performed to investigate differences in the mesoscopic disorder as induced by the process of electrospinning. The changes observed in the Pauli susceptibility, EPR lineshape, EPR linewidth, and dc conductivity are interpreted as due to increased chain alignment in the fibers compared with the cast films.     

New constant-frequency current-mode control for power converters,stable for all values of duty ratio, and usable in all four quadrants

A constant-frequency, current-mode, pulse-width modulator (PWM) for switching power converters is presented. The PWM is stable for any value of the duty ration (δ) and is suitable for operation in one to four quadrants of the output current-voltage plane. The control system can be used with most DC-DC power-converter topologies. Due to its unique properties of δ range stability and four-quadrant operation, the control process is particularly useful in DC-AC conversion. The process is clearly advantageous compared to the other current-mode control method, the bang-bang process. It has all the advantages inherent to constant-frequency operation, including the possibility of paralleling different converters without low-frequency beating and the suppression of low-frequency subharmonics in DC-AC conversion     

A practical procedure to analyze singular configurations in closed kinematic chains

The authors present a general method for the automated singularity analysis of any mechanism at a given configuration. The procedure uses a base of the motion space. This is obtained from a velocity equation characterized by a geometric matrix. This special form of Jacobian matrix has some advantages for automatic implementation. This approach provides the degree of freedom associated with the singularity, uncontrolled motion, and kinematic dependencies. It also facilitates the choice of actuators and redundant devices. The method has been implemented in a computer program for kinematic analysis.     

Propylene Solubility in Toluene and Isododecane

Propylene solubility in toluene and isododecane (2,2,4,6,6‐Pentamethylheptane, CA Registry# 13475‐82‐6) was measured at different temperatures and pressures, similar to the ones normally used to carry out propylene polymerizations through metallocene and Ziegler‐Natta catalysts. Experimental data were obtained with a gravimetric method, where experimental liquid phase compositions are measured at known temperature and pressure conditions. The experimental data were modeled with two different models: the Wilson excess Gibbs free energy model and an empirical model. Both modeling approaches may be recommended for analysis of kinetic data obtained for slurry propylene polymerizations in toluene and isododecane.     

Failure prediction of composite T-beams subjected to lateral load on the web

A study of the design and mechanical behaviour of co-cured T-beams subjected to lateral loading on the web is presented. The T-beams were manufactured by press moulding from pre-pregs of uni-directional and fabric glass reinforced high performance epoxy matrix. A special fixture was designed in order to carry out tests where the T-beams were laterally loaded on the web and clamped on the flange. Analytical and numerical studies were performed to predict the failure load to compare with the experimental results. The multilayer anisotropic continuum theory for delamination analysis of curved beams subjected to end moments and forces was used to compute the delamination stresses in the quarter cylindrical beam of the junction between the flange and the web. Finite element analyses of the T-beams were performed using plate/shell elements and two models were used for the joining between web and flange, to compute the planar stresses in the beam. The scatter obtained in the experimental results can be explained by the presence of two failure modes: one due to delamination associated with the through the thickness stresses developed in the curved part of the beam, the other related with failure occurring due to tangential stresses in the most highly stressed plies.     

A thermal-fully hydrodynamic model for semiconductor devices andapplications to III-V HBT simulation

Because of the interaction between self-heating and hot carriers effects, neither isothermal nor conventional macrothermal models are adequate for the simulation of state-of-the-art power devices; instead, a detailed electro-thermal model accounting for nonstationary transport, such as the Thermal-Fully Hydrodynamic (T-FH) model, is required. We apply a one-dimensional (1-D) implementation of such a model to the simulation of AlGaAs/GaAs and InP/InGaAs Heterojunction Bipolar Transistors (HBTs), comparing the results with those provided by simplified models, and highlighting how deeply both nonlocal transport and self-heating affect the predicted device performance. The importance of the convective terms is assessed, and a new nonthermal mechanism for the output Negative Differential Resistance (NDR) is proposed     

Effects of chronic administration of alcohol on neural mechanisms of arterial blood pressure regulation]

Metaphor comprehension was studied in schizophrenics as compared to psychiatric and nonpsychiatric controls. Subjects were asked in a two-condition forced-choice response task to detect the metaphor similar or contrary to a proverb with an abstract meaning. Schizophrenic patients were impaired in both conditions. However, the paranoid patients' performances did not differ from psychiatric and nonpsychiatric controls. These results are consistent with the hypothesis that the ability of metaphorizing is preserved in some schizophrenic patients.     

Roles of temperamental arousal and gender-segregated play in young children's social adjustment.

The hypothesis that gender differences in children's adjustment is partially influenced by differences in temperament and interactions with same-sex peers was examined. Fifty-seven predominantly White, middle-class preschoolers (29 boys and 28 girls, M age?=?54.5 months) participated. Measures were taken of children's arousability, problem behaviors, and tendencies to play with same-sex peers. A semester later, children's peer status was assessed. Analyses revealed that arousability and same-sex peer play interacted to predict problem behaviors. For boys high in arousability, play with same-sex peers increased problem behaviors. In contrast, arousable girls who played with other girls were relatively unlikely to show problem behaviors. Moreover, the interaction of arousability and same-sex peer play predicted boys' (but not girls') peer status, and this relation was partially mediated by problem behaviors. The role of gender-related processes is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)