Antioxidant performance of mixed tocopherols in styrenic block copolymers

Mixed tocopherols (MT) containing a predominance of γ‐tocopherol were evaluated for antioxidant (AO) performance in polybutadiene‐ and polyisoprene‐based styrenic block copolymers (SBS and SIS, respectively) by using oxidative induction time as a measure of AO performance. A conventional hindered phenolic AO and α‐tocopherol (vitamin E) were evaluated in comparison. MT exhibited significantly higher performance than the controls in both SIS and SBS polymers. J. VINYL ADDIT. TECHNOL., 12:73–77, 2006. © 2006 Society of Plastics Engineers     

A Fifth Order Flux Implicit WENO Method

The weighted essentially non-oscillatory (WENO) method is an excellent spatial discretization for hyperbolic partial differential equations with discontinuous solutions. However, the time-step restriction associated with explicit methods may pose severe limitations on their use in applications requiring large scale computations. An efficient implicit WENO method is necessary. In this paper, we propose a prototype flux-implicit WENO (iWENO) method. Numerical tests on classical scalar equations show that this is a viable and stable method, which requires appropriate time-stepping methods. Future study will include the examination of such methods as well as extension of iWENO to systems and higher dimensional problems.Sigal Gottlieb - The work of this author supported by NSF grant DMS-0106743.Steven J. Ruuth - The work of this author was partially supported by a grant from NSERC Canada.     

Self-image resilience and dissonance: The role of affirmational resources.

Predicted that high self-esteem Ss (HSEs) would rationalize an esteem-threatening decision less than low self-esteem Ss (LSEs), because HSEs presumably had more favorable self-concepts with which to affirm, and thus repair, their overall sense of self-integrity. This prediction was supported in 2 experiments within the "free-choice" dissonance paradigm: one that manipulated self-esteem through personality feedback and the other that varied it through selection of HSEs and LSEs, but only when Ss were made to focus on their self-concepts. A 3rd experiment countered an alternative explanation of the results in terms of mood effects that may have accompanied the experimental manipulations. Results were discussed in terms of the following: (1) their support for a resources theory of individual differences in resilience to self-image threats—an extension of self-affirmation theory, (2) their implications for self-esteem functioning, and (3) their implications for the continuing debate over self-enhancement vs self-consistency motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Information Assurance Technology Forecast 2008

A virtual roundtable (featuring panelists Steven Bellovin, Terry Benzel, Bob Blakely, Dorothy Denning, Whitfield Diffie, Jeremy Epstein, and Paulo Verissimo) discussing the next 15 years in computer security.     

Recognizing, assessing, and intervening with problems of professional competence.

Working collaboratively, psychologist educators and trainers at the doctoral, internship, and postdoctoral levels; credentialers; practitioners; and students offer 8 proposals for psychologists to consider in recognizing, assessing, and intervening with problems of professional competence in students and practicing professionals. In the proposals, the authors address the following topics: definitions and categories; preparing the system; self-assessment; remediation; diversity; communication across various levels of the system; confidentiality; and ethical, regulatory, and legal underpinnings. They also propose future directions for the assessment of problems in professional competence in both students and practicing psychologists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterization of Dip-Coated Boron Nitride on Silicon Carbide Fibers

Amorphous boron nitride thin coatings (∼0.2 μm) have been formed on Nicalon and C-Nicaion (pre-carbon-coated Nicalon) yarns via dip coating in boric acid solution followed by heating and nitriding in NH₃gas at 1000°C. X-ray photoelectron spectroscopy (XPS) and Auger electron spec-troscopy (AES) studies have shown the formation of boron nitride. The coating was boron rich and contains oxygen. The N/B and O/B ratios range from 0.6 to 0.8 and from 0.1 to 0.25, respectively. Tensile strength measurements revealed that the BN-coated C-Nicalon yarn maintained ∼85% of its original strength while BN-coated Nicalon lost ∼85% of its original strength. Auger depth profiles showed that there was a consumption of carbon during the heating and nitridation process for both BN-coated Nicalon and C-Nicalon fibers. However, the depletion of carbon in BN-coated Nicalon fibers was much more severe than that in BN-coated C-Nicalon fibers.     

Post-traumatic stress disorder and smoking: a systematic review.

We conducted a systematic review of what is known about the relationship between post-traumatic stress disorder (PTSD) and smoking to guide research on underlying mechanisms and to facilitate the development of evidence-based tobacco treatments for this population of smokers. We searched Medline, PsychINFO, and the Cochrane Central Register of Controlled Trials and identified 45 studies for review that presented primary data on PTSD and smoking. Smoking rates were high among clinical samples with PTSD (40%-86%) as well as nonclinical populations with PTSD (34%-61%). Most studies showed a positive relationship between PTSD and smoking and nicotine dependence, with odds ratios ranging between 2.04 and 4.52. Findings also suggest that PTSD, rather than trauma exposure itself, is more influential for increasing risk of smoking. A small but growing literature has examined psychological factors related to smoking initiation and maintenance and the overlapping neurobiology of PTSD and nicotine dependence. Observational studies indicate that smokers with PTSD have lower quit rates than do smokers without PTSD. Yet a few tobacco cessation treatment trials in smokers with PTSD have achieved quit rates comparable with controlled trials of smokers without mental disorders. In conclusion, the evidence points to a causal relationship between PTSD and smoking that may be bidirectional. Specific PTSD symptoms may contribute to smoking and disrupt cessation attempts. Intervention studies that test behavioral and pharmacological interventions designed specifically for use in patients with PTSD are needed to reduce morbidity and mortality in this population.     

Accelerating the hydration of calcium sulfate hemihydrate via high energy mixing

High energy mixing of calcium sulfate hemihydrate/water slurries provides a means to accelerate the hydration leading to gypsum formation. Additional benefits associated with high energy mixing include enhanced strength of the resulting gypsum casts. In order to exploit the advantages of high energy mixing, an understanding of the relationship between mixing energy and set acceleration is needed. The present study investigated the relationship between a chemical accelerator and high energy mixing for the purpose of set acceleration. A mathematical model of this relationship allows calculation of the time to achieve 50% hydration given the added specific mixing energy, the percentage of added chemical accelerator by weight of stucco, and the water to stucco ratio for a given slurry. Use of this model along with experimental data allowed a comparison of the accelerative efficacy of mixing energy relative to chemical accelerator. The results show that the accelerative capacity of high energy mixing is rather modest compared to that of the chemical accelerator, with a ten-fold increase in mixing energy required to maintain the same time to achieve 50% hydration when the chemical accelerator loading is reduced by 0.03%.