The effect of an Al2O3 dispersion on the adhesion of Al2O3 scales on aluminized Co-10% Cr alloys

The beneficial effect of dispersions of reactive-metal oxide particles on the adhesion of Cr₂O₃ and Al₂O₃ scales formed on heat-resisting alloys is wellknown. It has been shown that an Al₂O₃ dispersion in an alloy can improve the adhesion of a Cr₂O₃ scale, and it is of particular interest in assessing the various theoretical proposals for the effect to determine whether such a dispersion can affect the adhesion of an Al₂O₃ scale. In this investigation, a Co–10% Cr–1 % Al alloy was first internally oxidized to form an Al₂O₃ dispersion. This alloy was then aluminized so that on subsequent oxidation an Al₂O₃ scale developed. It was shown that the dispersion did indeed improve the scale adhesion. The implications of this result are discussed.     

Holographic reprocessing: Empirical evidence to reduce posttraumatic cognitions in women veterans with PTSD from sexual trauma and abuse.

Holographic reprocessing (HR) facilitates holistic reappraisal of attributions regarding interpersonal violence and maltreatment. The authors tested the feasibility to train therapists to run a protocol using HR to reduce negative thoughts associated with posttraumatic stress disorder (PTSD) in women veterans who have had sexual trauma or abuse. The study assessed pre- and postscores on the Posttraumatic Cognitions Inventory (PTCI) in a naturalistic clinical setting with 5 therapists. The protocol consisted of screening for PTSD, followed by an average of 9 HR treatment sessions. Twenty-two women were referred to the study; 17 enrolled and completed treatment (0% dropout rate). Significant decreases were found on all scales of the PTCI, with large effect sizes: total negative thoughts, t(16) = 4.42, p     

Sensory modality, temperament, and the development of sustained attention: A vigilance study in children and adults.

Applying optimal stimulation theory, the present study explored the development of sustained attention as a dynamic process. It examined the interaction of modality and temperament over time in children and adults. Second-grade children and college-aged adults performed auditory and visual vigilance tasks. Using the Carey temperament questionnaires (S. C. McDevitt & W. B. Carey, 1995), the authors classified participants according to temperament composites of reactivity and task orientation. In a preliminary study, tasks were equated across age and modality using d= matching procedures. In the main experiment, 48 children and 48 adults performed these calibrated tasks. The auditory task proved more difficult for both children and adults. Intermodal relations changed with age: Performance across modality was significantly correlated for children but not for adults. Although temperament did not significantly predict performance in adults, it did for children. The temperament effects observed in children-specifically in those with the composite of reactivity-occurred in connection with the auditory task and in a manner consistent with theoretical predictions derived from optimal stimulation theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fabrication of Optically Transparent and Electrooptic Strontium Barium Niobate Ceramics

The tetragonal tungsten bronze (TTB) type of Sr _x Ba_{1− x} ^m Nb₂O₆ (SBN) (0.5 ≤ x ≤ 0.75) was synthesized by a mixed-oxide route. Using the two-step densification process of pressureless sintering followed by oxygen HIPing, transparent ceramics were successfully fabricated. Microstructural, dielectric, optical, and electrooptic properties were investigated. All single-phase TTB-type SBN showed the characteristics of relaxor ferroelectrics. The extinction coefficients of the sample with the highest transparency were calculated from transmission spectra to be 30.4, 5.8, and 2.4 cm⁻¹ at 600, 1450, and 2000 nm, respectively. The linear electrooptic coefficients for SBN55, r ₃₃ and r ₁₃, were 46 × 10⁻¹² and 21 × 10⁻¹² m/V at 633 nm, respectively.     

Structural contingency theory and individual differences: Examination of external and internal person-team fit.

This article develops and tests a structurally based, integrated theory of person-team fit. The theory developed is an extension of structural contingency theory and considers issues of external fit simultaneously with its examination of internal fit at the team level. Results from 80 teams working on an interdependent team task indicate that divisional structures demand high levels of cognitive ability on the part of teammembers. However, the advantages of high cognitive ability in divisional structures are neutralized when there is poor external fit between the structure and the environment. Instead, emotional stability becomes a critical factor among teammembers when a divisional structure is out of alignment with its environment. Individual differences seem to play little or no role in functional structures, regardless of the degree of external fit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Understanding marriage and marital distress: Do milliseconds matter?

This article addresses concerns raised about F. D. Fincham, P. C. Garnier, S. Gano-Phillips, and L. N. Osborne's (1995) study by placing it in the context of current marital research. Studies of marriage-related cognitions have centered on the content of cognitions and have ignored the cognitive processes that give rise to them. Therefore, little is known about spousal cognitions that are unavailable for self-report or about the role of cognitive processes in initiating, maintaining, or alleviating marital distress. Reaction time has the potential to be one of several variables that can be used to investigate such processes. The challenge faced by marital researchers is to incorporate the information-processing paradigm into their work, thereby integrating it with broader literatures in cognitive psychology and social cognition. Failure to do so will leave marital researchers with an incomplete picture of marriage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Drilling of composite structures

Structural parts made of composites have frequently to be drilled in the aircraft industry. However, little is know about the interacting conditions between the drilling tool and the material, which may be multi-type and multi-size. This study proposes a model which links the axial penetration of the drill bit to the conditions of delamination (crack opening mode I) of the last few plies. Several types of tool/material contact conditions were analyzed and were compared with experimental measurements, and with a model taken from the literature. Our study shows a close correlation between experiment and calculation when the thrust force of the drill is modeled by taking into account the geometrical nature of the contact between the tool and a laminate composite material.     

Organizational Injustice and Psychological Strain.

Characterizing perceived injustice as a form of stress, we examined the main and interactive relationships among interactional, procedural, and distributive injustice and psychological strain while controlling for job insecurity. Using moderated multiple regression analysis with a sample of 1,083 government employees, we show that interactional, procedural, and distributive injustice are all unique predictors of psychological strain that account for significant unique variance beyond that explained by job insecurity. Those individuals who perceive more interactional, procedural, or distributive injustice at work reported a higher degree of strain. However, there were no significant interactive effects, suggesting that these three categories of perceived injustice do not interact to predict symptoms of psychological strain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Not Just “A Roof over Your Head”: The Meaning of Healthy Housing for People Living with HIV

The literature has identified housing as a fundamental unmet need for people living with HIV; yet there has been little qualitative evidence exploring housing and HIV, particularly from a Canadian context. This paper focuses on our qualitative analyses of the housing experiences of 48 HIV-positive people living in Ontario. Findings from our interviews illustrate healthy housing as a dynamic interconnection between health, housing and other social factors that are influential to the health and well-being of people with HIV. Four salient themes have emerged from our qualitative findings: the interplay between healthy housing and economic security; the relationship between HIV, health and housing precariousness; the interconnection between housing, HIV, safety, stigma, social isolation and social exclusion; and the meaning of healthy housing for people living with HIV. These findings re-emphasize the importance of housing policies that consider housing as more than just a roof over one’s head, but also as something that supports the physical, mental, emotional and social well-being of people living with HIV.     

Analytical models of composite material drilling

Drilling of composite material structures is widely used for aeronautical assemblies. When drilling, damage to the composite laminate is directly related to the cutter geometry and the cutting conditions. Delamination of the composite materials at the hole exit as directly related to the axial force (F _Z) of the cutter is considered to be the major such defect. To address this issue, an orthotropic analytical model is developed in order to calculate the critical force of delamination during drilling and a number of hypotheses for loading are proposed. This critical axial load is related to the delamination conditions (propagation of cracks in the last layers) and the mechanical characteristics of the composite material machined. A numerical model is also drawn up to allow for numerical validation of the analytical approach. A comparison between these analytical and numerical modellings and experimental results from quasi-static punch tests led to the choice of the loading hypothesis closest to the experimental conditions. The selection of corresponding load permits to model the drilling critical thrust force on delamination and then to optimise the cutting conditions. The dimensions and geometrical shape of the cutter are of considerable importance when it comes to choosing this load. The present article focuses on the case of the twist drill, which is commonly used to drill thick plates. However, this work can be adapted to different cutter geometries.