The infrared infiltration and joining of advanced material

JOM - Infrared processing is a newly developed technique for materials processing. Key features include rapid processing, simplicity, and low cost. Because of the rapid processing, very little...     

Perceived control over caregiving outcomes: Implications for child abuse.

We predicted low perceived caregiver control over caregiving failure to be related to (a) coercive or abusive parenting and (b) affective reactions to "difficult" children. On the basis of a multidimensional scaling analysis of the Parent Attribution Test (Study 1), we constructed a scale (PCF) that assessed perceived balance of control over caregiving failure (attributed control to caregivers vs attributed control to children). In Study 2, we found low PCF to predict abusiveness and nonabusive coerciveness among mothers in counseling at a child abuse agency. Additionally, we found low PCF to predict experienced annoyance/irritation among unrelated mothers interacting with children at relatively high risk for abuse (compared with their lower-risk siblings). We interpreted results as demonstrating the potential importance of low perceived control as a moderator of negative affect in response to difficult children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Design of microfluidic channels for magnetic separation of malaria-infected red blood cells

This study is motivated by the development of a blood cell filtration device for removal of malaria-infected, parasitized red blood cells (pRBCs). The blood was modeled as a multi-component fluid using the computational fluid dynamics discrete element method (CFD-DEM), wherein plasma was treated as a Newtonian fluid and the red blood cells (RBCs) were modeled as soft-sphere solid particles which move under the influence of drag, collisions with other RBCs, and a magnetic force. The CFD-DEM model was first validated by a comparison with experimental data from Han and Frazier (Lab Chip 6:265–273, 2006) involving a microfluidic magnetophoretic separator for paramagnetic deoxygenated blood cells. The computational model was then applied to a parametric study of a parallel-plate separator having hematocrit of 40 % with 10 % of the RBCs as pRBCs. Specifically, we investigated the hypothesis of introducing an upstream constriction to the channel to divert the magnetic cells within the near-wall layer where the magnetic force is greatest. Simulations compared the efficacy of various geometries upon the stratification efficiency of the pRBCs. For a channel with nominal height of 100 µm, the addition of an upstream constriction of 80 % improved the proportion of pRBCs retained adjacent to the magnetic wall (separation efficiency) by almost twofold, from 26 to 49 %. Further addition of a downstream diffuser reduced remixing and hence improved separation efficiency to 72 %. The constriction introduced a greater pressure drop (from 17 to 495 Pa), which should be considered when scaling up this design for a clinical-sized system. Overall, the advantages of this design include its ability to accommodate physiological hematocrit and high throughput, which is critical for clinical implementation as a blood-filtration system.     

Speech intelligibility measured with shortened versions of Callsign Acquisition Test (CAT)

The Callsign Acquisition Test (CAT) is a new speech intelligibility test developed by the Human Research and Engineering Directorate of the U.S. Army Research Laboratory (ARL-HRED). CAT uses the phonetic alphabet and digit stimuli combined together to form 126 test items.

Objective

The purpose of this study was to assess the reliability of data collected with shorter versions of CAT.

Design

A total of 5 shorter versions of the original list (CAT-120, CAT-60, CAT-40, CAT-30, and CAT-24) were formed and evaluated using 19 participants. Each of the subsets of CAT was presented in pink noise at signal-to-noise ratios (SNRs) of −6 dB and −9 dB.

Results

Results showed that shortened CAT lists have the capability of providing the same predictive power as the full CAT with good test-retest reliability.

Conclusions

Under the experimental conditions of this study, any of the shorter versions of the CAT can be utilized in place of the full version to reduce testing times with no effect on predictive power.     

Development of refractory armored silicon carbide by infrared transient liquid phase processing

Tungsten (W) and molybdenum (Mo) were coated on silicon carbide (SiC) for use as a refractory armor using a high power plasma arc lamp at powers up to 23.5 MW/m² in an argon flow environment. Both tungsten powder and molybdenum powder melted and formed coating layers on silicon carbide within a few seconds. The effect of substrate pre-treatment (vapor deposition of titanium (Ti) and tungsten, and annealing) and sample heating conditions on microstructure of the coating and coating/substrate interface were investigated. The microstructure was observed by scanning electron microscopy (SEM) and optical microscopy (OM). The mechanical properties of the coated materials were evaluated by four-point flexural tests. A strong tungsten coating was successfully applied to the silicon carbide substrate. Tungsten vapor deposition and pre-heating at 5.2 MW/m² made for a refractory layer containing no cracks propagating into the silicon carbide substrate. The tungsten coating was formed without the thick reaction layer. For this study, small tungsten carbide grains were observed adjacent to the interface in all conditions. In addition, relatively large, widely scattered tungsten carbide grains and a eutectic structure of tungsten and silicon were observed through the thickness in the coatings formed at lower powers and longer heating times. The strength of the silicon carbide substrate was somewhat decreased as a result of the processing. Vapor deposition of tungsten prior to powder coating helped prevent this degradation. In contrast, molybdenum coating was more challenging than tungsten coating due to the larger coefficient of thermal expansion (CTE) mismatch as compared to tungsten and silicon carbide. From this work it is concluded that refractory armoring of silicon carbide by Infrared Transient Liquid Phase Processing is possible. The tungsten armored silicon carbide samples proved uniform, strong, and capable of withstanding thermal fatigue testing.     

An acoustic aneurysm-detector

Intracranial aneurysms have a high prevalence in the adult population; and if they rupture, significant morbidity almost always ensues. However, pulsatile blood flow through aneurysms produces vibrational sound patterns that may be detected extracranially. Thus, an acoustic aneurysm-detector has been developed to detect the sounds produced by intracranial aneurysms prior to rupture. The design is based on the utilization of a hydrophone for signal detection and computational signal processing for signal extraction. Data are examined in the time domain, the frequency domain, and the time-frequency plane. Examples are presented from an animal model and from a patient with a known aneurysm.     

Athlon XP／MP的倍频破解

本文是在自己调试破解成功后制作完成，如有雷同纯属巧合。　Ｅｘｔｒａ　ｐｅｒｆｏｒｍａｎｃｅ标志着超越性能极限的Ａｔｈｌｏｎ　ＸＰ的真正的由来。很多用户都非常了解ＡＭＤ新款的处理器Ａｔｈｌｏｎ　ＸＰ，它那超强的性能和低廉的价格令人然心动。新的Ａｔｈｌｏｎ　ＸＰ拥有超强的性能，当然要用来超频，可是Ａｔｈｌｏｎ　ＸＰ是将倍频锁定的，所以一般我们都是超Ａｔｈｌｏｎ　ＸＰ的外频，可是外频的可超频的的幅度十分有限，不如倍频来的方便和实用。　不少用户应该知道Ａｔｈｌｏｎ的旧款ＣＰＵ　雷鸟和Ｄｕｒｏｎ只要用２Ｂ…     

铝基牺牲阳极材料合金化研究进展

铝基牺牲阳极合金具有理论电容量大、电位适中、原料丰富等优点而普遍受到人们的重视。本文概述了近年来的铝基牺牲阳极材料的发展,总结了其合金化理论的发展变化,在分析铝阳极合金化活化规律及研究手段的基础上,讨论了几种被广泛接受的活化机理,并提出多种活化机制联合作用是活化机理的研究方向。     

Control of interfaces in Al-C fibre composites

The interface of Al-C fibre composite was modified by coating a silver layer on the surface of carbon fibres prior to making composites, in an attempt to improve the wettability between molten aluminium and carbon fibres during infiltration. An electroless plating technique was adopted and perfected to provide a homogeneous silver coating on the carbon fibre surface. Al-C fibre composites were prepared using a liquid infiltration technique in a vacuum. It was found that silver coating promoted the wetting between aluminium and carbon fibres, particularly with polyacrylonitrile-base carbon fibres. However, due to rapid dissolution of silver in molten aluminium, it was believed that the improved infiltration was not due to the wetting behaviour between molten aluminium and silver. The cleaning of the fibre surface and the preservation of the cleaned carbon surface with silver coating was considered to be the prime reason for the improved wettability. Interfacial reactions between aluminium and carbon fibres were observed. Amorphous carbon was found to react more with aluminium than graphitic carbon. This is believed to be because of the inertness of the graphitic basal planes.     

Monosialoganglioside GM1 inhibits neurotoxicity after hypothermic circulatory arrest

BACKGROUND/AIM: A herbal medicine, Sho-saiko-to (TJ-9), has recently been orally administered to patients with chronic liver disease in Japan and has been reported to inhibit the development of hepatocellular carcinoma. The aim of this study was to investigate whether TJ-9 has an inhibitory effect on the development of preneoplastic lesions and liver fibrosis in rats. METHODS: The effects of the TJ-9 were examined using the choline-deficient L-amino acid-defined (CDAA) diet-induced liver fibrosis model in 16-week-old male Wistar rats. RESULTS: TJ-9 (1% w/w) prevented fibrosis, as indicated by reduced hydroxyproline content in the liver and inhibition of the increase in a serum marker of fibrosis (hyaluronic acid), without reducing the increase in serum alanine aminotransferase and aspartate aminotransferase. TJ-9 also reduced the expression of type III procollagen alpha 1 mRNA in the liver, as well as the proliferation of myofibroblast-like cells (activated stellate cells, activated Ito cells). Furthermore, TJ-9 reduced the number of preneoplastic lesions, detected as enzyme-altered (glutathione S-transferase placental form-positive) lesions, in the liver. CONCLUSIONS: These results indicate that the herbal medicine Sho-saiko-to (TJ-9) prevents fibrosis as well as preneoplastic lesions, not by inhibiting hepatocyte cell death but by inhibiting the activation of stellate cells, which are considered to be the main collagen-producing cells, leading to a reduction in the development of preneoplastic lesions.