Deposition of hydrogenated amorphous carbon films from CH4/Ar plasmas: Ar dilution effects

Hydrogenated amorphous carbon (a-C:H) films were deposited, at room temperature, from a CH₄/Ar plasma produced by a radio frequency (r.f.) glow discharge system at 13.56 MHz, and different power values. Two different characterisation techniques, Raman and FTIR spectroscopies, have been used to investigate correlations between deposition conditions and properties of hydrogenated amorphous carbon films. The composition of the initial gaseous mixture and the r.f. power input are shown to affect significantly both mechanical and microstructural properties of deposited films. As the fraction of argon in the feed gas is increased, the deposition rate increases and the deposited film shows a higher friction coefficient, thus suggesting the production of a softer material. On the other hand, Raman measurements suggest the occurrence of a lower degree of structural order in the sp² lattice. Experimental findings are discussed in terms of the different chemical composition of the plasma.     

Parental involvement, homework, and TV time: Direct and indirect effects on high school achievement.

Examined the direct and indirect effects of TV time, homework, and parental involvement on high school seniors' achievement using 28,051 high school seniors selected from the dataset of the High School and Beyond Longitudinal Study conducted by the National Opinion Research Center (1980). Data indicate that homework had an important, positive effect on student achievement, and TV time had a smaller, negative effect. Parental involvement had no direct effect on seniors' achievement scores but did positively influence the amount of time that seniors spent on homework. Further analysis suggested the possibilities of low homework demands and of excessive weekday TV viewing. Given the time spent on TV and homework and their influence on achievement, it is suggested that these variables be considered in the push for educational improvement. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dysfunctional attitudes and attribution style in healthy controls and patients with schizophrenia, psychotic depression, and nonpsychotic depression.

Compared the scores of 242 psychiatric inpatients with schizophrenia, psychotic depression, or nonpsychotic depression and 53 healthy controls on the Attribution Style Questionnaire (ASQ) and the Dysfunctional Attitude Scale (DAS). Results provide mixed support for the cognitive and learned helplessness models of depression. Depressed Ss scored significantly higher than healthy controls on the DAS and ASQ, but there were no differences between depressed and schizophrenic Ss. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transition to adulthood as a parent-youth project: Governance transfer, career promotion, and relational processes.

This study determined how youth (ages 17-21) and their parents jointly constructed and acted on goals and strategies pertinent to the transition to adulthood. Twenty parent-youth dyads were followed over an 8-month period using the qualitative action-project method. Data included their joint conversations, video recall of internal processes, self-monitoring logs, and researcher telephone monitoring. Detailed and repeated analysis of elements, functional steps, and goals resulted in the identification of an explicit joint project for each dyad that the participants saw as pertinent to the transition to adulthood. These projects referred broadly to the youth development of identity and social inclusion in the adult world and included the specific projects of career promotion, governance transfer, and parent-youth relational processes. The findings illustrate the complexity of the transition-to-adulthood process as well as its joint construction by parent and youth. Implications for practice include identifying and following the joint parent-youth transition project. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The statistical analysis of data from small groups.

The authors elaborate the complications and the opportunities inherent in the statistical analysis of small-group data. They begin by discussing nonindependence of group members' scores and then consider standard methods for the analysis of small-group data and determine that these methods do not take into account this nonindependence. A new method is proposed that uses multilevel modeling and allows for negative nonindependence and mutual influence. Finally, the complications of interactions, different group sizes, and differential effects are considered. The authors strongly urge that the analysis model of data from small-group studies should mirror the psychological processes that generate those data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contact stress distributions in a turbine disc dovetail type joint - a comparison of photoelastic and finite element results

Two dimensional photoelastic frozen stress techniques were used to investigate the stress distributions of an axially loaded dovetail joint as is found in the design of some turbine blade-disc fixings. The internal stress distributions were obtained by the shear difference method and were compared to results obtained by using the finite element method. It was found that steep principal stress gradients were present immediately below the contact surfaces in the zone adjacent to the fillet radius of the dovetail fixing, which could be an important consideration in the fatigue strength of the joint. The finite element model used gave the same trends of stress as the photoelastic model, predicted higher peak principal stresses and did not exhibit the same detailed variations of stress distribution.     

Processing of short‐fiber reinforced polypropylene. I. Influence of processing conditions on the morphology of extruded filaments

An experimental investigation of the processing of glass fiber reinforced polypropylene is presented. Final fiber orientation distribution, fiber distribution in filament sections, rheological properties, final fiber length distribution and surface morphology were analyzed. This analysis was done taking into account the quantity of fibers and their interactions and flow conditions. The final fiber orientation increased when shear rate increased and fiber concentration decreased. Moreover, inhomogeneities in fiber distribution increased as the concentration of fibers decreased. The density profile showed a significant variation with fiber concentration, but it was not dependent on the shear rate applied. The viscosity showed a linear dependence with shear rate. The average fiber length and the breadth of this distribution decreased with the increasing fiber concentration and extrusion rate. The extruded filament surface showed minor roughness when the shear rate increased or when the fiber concentration decreased. The results of this experimental characterization give useful information to determine the influence of the processing variables on the final properties of short‐fiber reinforced polypropylene and constitutes the first part of a more ambitious project that also includes the development of a modeling strategy of the processing behavior for short‐fiber composites.     

Effect of total parenteral nutrition with linoleic acid-rich emulsions on tissue ω6 and ω3 fatty acids in the rat

Lipids - The effect of total parenteral nutrition (TPN) with lipid emulsions containing ca. 48% 18∶2ω6 plus 8% 18∶3ω3 (Intralipid®) or 76% 18∶2ω6 plus 0.5%...     

Relative contributions of expressive behavior and contextual information to the judgment of the emotional state of another.

Used a technique for assessing the relative impact of facial–gestural expressions, as opposed to contextual information regarding the elicitor and situation, on the judgment of emotion. In Study 1, 28 undergraduates rated videotapes of spontaneous facial–gestural expressions and separately rated the emotionally loaded color slides that elicited those expressions. The source clarities of the expressions and slides were matched using correlation and distance measures, and 18 expressions and 9 slides were selected. In Study 2, 72 undergraduate receivers were shown systematic pairings of these expressions and slides and rated the emotional state of the expresser, who was supposedly watching that slide under public or private situational conditions. Expressions were found to be more important sources for all emotion judgments. For female receivers slides were relatively more important in the public than the private situation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)