Environmental effects on the strength and impact damage resistance of alumina based oxide/oxide ceramic matrix composites

In this study the effects of high temperature and moisture on the impact damage resistance and mechanical strength of Nextel 610/alumina silicate ceramic matrix composites were experimentally evaluated. Composite laminates were exposed to either a 1050°C isothermal furnace-based environment for 30 consecutive days at 6 h a day, or 95% relative humidity environment for 13 consecutive days at 67°C. Low velocity impact, tensile and short beam strength tests were performed on both ambient and environmentally conditioned laminates and damage was characterized using a combination of non-destructive and destructive techniques. High temperature and humidity environmental exposure adversely affected the impact resistance of the composite laminates. For all the environments, planar internal damage area was greater than the back side dent area, which in turn was greater than the impactor side dent area. Evidence of environmental embrittlement through a stiffer tensile response was noted for the high temperature exposed laminates while the short beam strength tests showed greater propensity for interlaminar shear failure in the moisture exposed laminates. Destructive evaluations exposed larger, more pronounced delaminations in the environmentally conditioned laminates in comparison to the ambient ones. External damage metrics of the impactor side dent depth and area directly influenced the post-impact tensile strength of the laminates while no such trend between internal damage area and residual strength could be ascertained.     

Psychopathy, IQ, and Violence in European American and African American County Jail Inmates.

The accuracy of the prediction of criminal violence may be improved by combining psychopathy with other variables that have been found to predict violence. Research has suggested that assessing intelligence (i.e., IQ) as well as psychopathy improves the accuracy of violence prediction. In the present study, the authors tested this hypothesis by using a contemporary measure of psychopathy, the Psychopathy Checklist-Revised (R. D. Hare, 2003), in a sample of 326 European American and 348 African American male offenders. The postdictive power of psychopathy was evident for both ethnic groups and robust across most changes in the operationalization of violence and the analysis conducted, whereas the postdictive power of IQ was not. No Psychopathy x IQ interactions were identified. Implications of these results for violence prediction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

智能传感器接口的优势

采用智能化更高的传感器接口能将16位的高性能CPU与16位ADC的处理功能相结合，从而大幅简化设计工作，尤其是在集成解决方案体积较小、价格较低的时候更是如此。本文将重点介绍上述数据采集系统架构的各种优势，其中包括更低功耗、更小体积、更少的主机CPU负载、功能齐备以及传输中可配置性等。     

Understanding massively multiplayer online role‐playing game addiction: A hedonic management perspective

Massively multiplayer online role‐playing game (MMORPG) addiction presents a serious issue worldwide and has attracted increasing attention from academic and other public communities. This article addresses this critical issue and fills research gaps by proposing and testing a research model of MMORPG addiction. Building on the conceptual foundation of the hedonic management model of addiction and the technology affordance perspective, we develop a research model explaining how MMORPG affordances (ie, achievement, social and immersion affordances) are associated with the duality of hedonic effects (ie, perceived positive mood enhancement and perceived negative mood reduction) and the extent of MMORPG addiction. Using structural equation modelling, we empirically test our research model with 406 MMORPG players. The results show that both perceived positive mood enhancement and perceived negative mood reduction positively correlate with the extent of MMORPG addiction. Furthermore, achievement and immersion affordances are positively associated with the duality of hedonic effects, whereas social affordance is not. Our study contributes to the growing body of technology addiction literature by revealing the relationships between the two hedonic effects and the extent of MMORPG addiction, and by offering a contextualised explanation of the role of MMORPG affordances in these relationships. We offer an alternative perspective on the far‐reaching, unintended relationships between technological affordances and addictive technology use. Our study provides game developers and policymakers with insights into preventing MMORPG addiction to create an entertaining, healthy virtual playground.     

Torrefied agro-industrial residue as filler in natural rubber compounds

This study explored the feasibility of using torrefied biomass as a reinforcing filler in natural rubber compounds. Carbon black was then replaced with the torrefied biomass in elastomer formulations for concentrations varying from 0% to 100% (60 parts per hundred rubber or phr total). Their influence on the curing process, dynamic properties, and mechanical properties was investigated. Results were compared with the properties of vulcanizates containing solely carbon black fillers. Time to cure (t₉₀) for compounds with torrefied biomass fillers increased, while filler-filler interactions (ΔG') decreased, compared to carbon black controls. At low strains, the tan δ values of the torrefied fillers vulcanizates were similar to the controls. Incorporation of torrefied biomass into natural rubber decreased compound tensile strength and modulus but increased elongation. Replacement with torrefied fillers resulted in a weaker filler network in the matrix. Still, results showed that moderate substitution concentrations (~20 phr) could be feasible for some natural rubber applications.     

Effect of silane structure on the properties of silanized multiwalled carbon nanotube-epoxy nanocomposites

Multiwalled carbon nanotubes (MWCNTs) were functionalized with aminosilanes via an aqueous deposition route. The size and morphology of siloxane oligomers grafted to the MWCNTs was tuned by varying the silane functionality and concentration and their effect on the properties of a filled epoxy system was investigated. The siloxane structure was found to profoundly affect the thermo-mechanical behavior of composites reinforced with the silanized MWCNTs. Well-defined siloxane brushes increased the epoxy T_g by up to 19 °C and significantly altered the network relaxation dynamics, while irregular, siloxane networks grafted to the MWCNTs had little effect. The addition of both types of silanized MWCNTs elicited improvements in the strength of the nanocomposites, but only the well-defined siloxane brushes engendered dramatic improvements in toughness. Because the silanization reaction is simple, rapid, and performed under aqueous conditions, it is also an industrially attractive functionalization route.     

Incorporating in-cylinder pressure data to predict NOx emissions from spark-ignition engines fueled with landfill gas/hydrogen mixtures

A 0.745 L 2-cylinder spark-ignition engine was operated with compressed natural gas and with simulated landfill gas (60% CH₄ and 40% CO₂ by volume) containing hydrogen concentrations of 0, 30%, 40%, and 50% (by volume of the CH₄ in the fuel) at constant rpm. This empirical data was compared with predictions from three existing semi-empirical engine models, using a first-law-based finite heat release model to correlate measured in-cylinder pressure data and burn rate for each fuel mixture. Of the three models only a two zone model incorporating thermal and prompt NO_x came within 25% of predicting the measured NO_x emissions.     

The ORF, regulated synthesis, and persistence-specific variation of influenza C viral NS1 protein

The open reading frame (ORF) and the regulated synthesis of the influenza C viral NS1 protein were analyzed in view of viruses possessing different biological activities. We provide evidence for a 246-amino-acid NS1-ORF, encoded by five viral strains and variants. Prokaryotic expression of the prototype NS1-ORF resulted in a product of 27 kDa, confirming the predicted molecular weight. Using an antiserum raised against recombinant NS1 protein, nonstructural proteins of wild-type virus were detected in infected cells for a limited course of time, whereas a persistent virus variant was characterized by a long-term nonstructural gene expression. As examined by infection experiments, the intracellular distribution of nonstructural protein was nuclear and cytoplasmic, whereas in NS1 gene-transfected cells, the cytoplasmic localization occurred in a fine-grained structure, suggesting an analogy to influenza A viral NS1 protein. Concerning persistent infection, NS1 protein species differing in sizes and posttranslational modifications were observed for a persistent virus variant, as particularly illustrated by a high degree of NS1 phosphorylation. Virus reassortant analyses proved the importance of the NS-coding genomic segment: the minimal viral properties required for the establishment of persistence were transferred with this segment to a monoreassortant virus. Thus the influenza C viral NS1 protein is a 246-amino-acid nuclear-cytoplasmic phosphoprotein that can be subject to specific variations being functionally linked to a persistent virus phenotype.