Mechanical Behavior of MoSi2 Reinforced–Si3N4Matrix Composites

The mechanical behavior of MoSi₂ reinforced–Si₃N₄ matrix composites was investigated as a function of MoSi₂ phase content, MoSi₂ phase size, and amount of MgO densification aid for the Si₃N₄ phase. Coarse-phase MoSi₂-Si₃N₄ composites exhibited higher room-temperature fracture toughness than fine-phase composites, reaching values >8 MP·am^1/2. Composite fracture toughness levels increased at elevated temperature. Fine-phase composites were stronger and more creep resistant than coarse phase composites. Room-temperature strengths >1000 MPa and impression creep rates of ∼10⁻⁸ s⁻¹ at 1200°C were observed. Increased MgO levels generally were deleterious to MoSi₂-Si₃N₄ mechanical properties. Internal stresses due to MoSi₂ and Si₃N₄ thermal expansion coefficient mismatch appeared to contribute to fracture toughening in MoSi₂-Si₃N₄ composites.     

Adult smoking intervention programmes in Massachusetts: a comprehensive approach with promising results

This paper provides a brief overview of the history of Massachusetts' opposition to smoking. It describes the current Massachusetts Tobacco Control Program and its smoking intervention programmes; changes in public opinion, perceptions and attitudes toward smoking; and programme impact. Massachusetts has been successful in developing a comprehensive intervention that has had encouraging results in changing public attitudes about smoking and in helping smokers to quit.     

Protein profiling of low-density lipoprotein from obese subjects

Although obesity and high levels of low-density lipoprotein (LDL) are well-known risk factors for cardiovascular disease, the precise role(s) of different LDL constituents in obesity has not been explored. In the present study, we compared the LDL proteome of healthy control adults (body mass index<25) and obese subjects (body mass index>30). LDL was isolated by density-gradient ultracentrifugation and proteins were separated with 2-D PAGE, quantified, and identified by peptide mass fingerprinting using MALDI-TOF MS. A new LDL-associated protein was identified as transthyretin and found to be significantly more abundant in LDL from the obese subjects. In addition, LDL from the obese subjects contained relatively more α(1) -antitrypsin, apo J, apo C-II, than LDL from controls, and also more of an acidic isoform (pI/Mr; 5.2/23 100) of apo A-I. On the other hand, the relative amounts of apo A-IV and the major isoform of apo A-I (pI/Mr; 5.3/23 100) were significantly less in LDL from the obese subjects. Apo E was less and non-sialylated apo C-III more abundant in LDL from obese men than control men, while there were no such differences between LDL from obese and control women. These findings illustrate that obesity is not only associated with increased LDL-cholesterol levels but also with alterations in the LDL protein composition. The presence of transthyretin in LDL from obese subjects may reflect over-nutrition and affect the lipid metabolism in obesity.     

A forecast‐based monitoring methodology for process transitions

Nonconforming parts are often produced when a process moves from one level to another due to transition events. Control charting, when applied to a stable state process, is an effective monitoring tool to continuously check for process shifts or upsets. However, the presence of transition events can impede the normal performance of traditional control chart with increased false alarms. The presence of autocorrelation also requires modification to the control charting procedure. We present a methodology for characterizing the process transition which involves a tracking signal statistic, based on the forecast‐based exponentially weighted moving average (EWMA). This test will supplement the forecast‐based EWMA control charting as a means of detecting when the transition event is complete. Such a procedure facilitates smooth application of the appropriate control chart by knowing when the transition is over. The transition characterization methodology also carries benefits in cost and material savings. We use a color transition process in plastic extrusion to illustrate a transition event and demonstrate our proposed methodology. Simulation is employed to evaluate the performance of the methodology. Copyright © 2001 John Wiley & Sons, Ltd.     

Automatic babble recognition for early detection of speech related disorders

We have developed a program, the Early Vocalization Analyzer (EVA), that analyses digitized recordings of infant vocalizations. The purpose of such a system is to automatically and reliably screen infants who may be at risk for later communication problems. EVA applies the landmark detection theory of Stevens et al., for the recognition of acoustic features in adult speech, to detect syllables in vocalizations produced by typically developing six to thirteen month old infants. We discuss the differences between adult-specific code and code written to analyse infant vocalizations. In a validity test, EVA achieved 90% agreement in marking 128 landmarks commonly identified by two human judges, was often closer to one or both judges than the humans were to each other. In a second test EVA and a human judge had 86% agreement in identifying 150 landmarks.     

Role of dopamine in d-amphetamine-induced euphoria in normal, healthy volunteers.

The present study evaluated the role of dopamine in the euphorigenic effects of d-amphetamine in normal volunteers. d-Amphetamine (20 mg) was administered alone and after pretreatment with pimozide (4 mg), fluphenazine (3 or 6 mg), or prazosin (1 or 2 mg) in 3 separate groups of participants. Subjective effects were measured at regular intervals. It was hypothesized that pimozide and fluphenazine, but not prazosin, would attenuate the euphorigenic effects of d-amphetamine. In all studies, d-amphetamine produced robust stimulant-like effects (e.g., increased scores on measures of arousal and euphoria). Although none of the antagonists significantly attenuated subjective responses to d-amphetamine, there were trends for both dopamine antagonists to reduce some responses. Both dopamine antagonists also produced modest effects when administered alone. These findings are inconsistent with those of studies with laboratory animals, perhaps because of differing experimental conditions. Alternatively, these findings raise the possibility that separate processes mediate drug reinforcement and euphoria. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Priming effects with drugs and other reinforcers.

Abstinent drug users often report that taking even a small amount of their previously abused drug increases their desire for the drug and can lead to a full relapse. This apparent "priming" effect of drugs has been studied in both laboratory animals and humans. In animals trained to self-administer drugs, small amounts of a previously self-administered drug readily reinstate responding. In humans, administration of a previously abused drug increases self-reported craving and desire for the drug. Priming effects also occur with other reinforcers (e.g., presentation of a food stimulus increases food-reinforced responding). This article examines the generality of priming phenomena, and it examines some of the learned or unlearned processes that underlie the effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Empirical support for credibility and giving in cross-cultural psychotherapy.

Comments on S. Sue and N. Zane's (see record 1987-16319-001) work, which suggests that clients' perception of 2 interrelated processes (credibility and giving) are essential for therapeutic efficacy in cross-cultural counseling and psychotherapy. Data collected by the present author support Sue and Zane's contention that unless the therapist conveys to the client a problem-solving capability and an ability to give something viewed as directly beneficial, cultural knowledge and techniques are inadequate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Künstliche Intelligenz auf dem Fußballplatz

Dieser Artikel beschreibt, worum es sich beim RoboCup und bei Studienprojekten handelt. Au?erdem stellt er exemplarisch die Roboter und Software des Teams CoPS Stuttgart vor.