David V. Smith (1943-2006).

Presents an obituary for David V. Smith, who succumbed to a brain tumor on September 30, 2006 at the age of 63. He was Simon R. Bruesch Professor and chair of the Department of Anatomy and Neurobiology and the director of the Neuroscience Institute at the University of Tennessee Health Science Center (UTHSC). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Off-Optimum Cure of Aerospace Epoxy Adhesives

Four epoxy film adhesives used in aircraft manufacture and repair have been examined to establish the effect of deviation from the cure cycle specified by the manufacturer. In addition to the variation of the cure cycle, two surface preparations of the aluminium adherends (chromic acid etch or grit blast followed by silane treatment) were evaluated. Thermal analysis was used to examine the cure envelope of the adhesive, and its extent of cure and glass transition temperature. The adhesive properties were assessed by shear strength (in both single lap joints and in Iosipescu configuration), durability (Boeing wedge test) and chemical resistance to selected aggressive fluids. The sensitivity of the performance of a particular adhesive to offoptimum cure conditions depends on its composition and needs to be determined, not predicted.     

Effect of physical aging on the fracture behavior of crosslinked epoxies

The effect of physical aging on the fracture behavior, crack opening displacement, and plastic deformation zone of unmodified and rubber-modified epoxies was determined at two aging temperatures and different displacement rates. The strain energy release rate decreases to between 40 and 50% (for rubber modified and unmodified samples, respectively) of the unaged values after 35 days aging. Systematic dependence of the decrease in fracture toughness by aging on the rubber content is not apparent. The increased yield stress after physical aging is the main factor contributing to the reduction in fracture toughness, crack opening displacement, and plastic deformation zone. Physical aging suppresses the crack blunting mechanisms in epoxies.     

Modeling Groups of Plausible Virtual Pedestrians

In a proposed methodology for modeling dynamic crowd scenarios, a video corpus informs the modeling process, after which the resultant animations undergo perception-based evaluation. The aim is to improve the crowd's visual plausibility rather than the simulation's correctness. A real-life crowd animation system demonstrates the methodology's practical application.     

Accounting for no difference/preference responses or ties in choice experiments

The analysis of choice data in which no difference/preference responses, or ties, occur is considered in this paper. A key issue addressed in the paper is the need for “identicality norms” for difference and preference tests. These norms reflect the researcher’s expectation for the number of ties that would have occurred in the experiment had the products tested been putatively identical. Without these norms, the issue of how to account for ties can never be fully resolved. After this idea is developed, some methods from the statistics literature to account for ties are reviewed and the Thurstonian 2-AC (2-Alternative Choice) model is discussed. Common practices of equal or proportional redistribution of ties are noted to be either conservative or liberal, respectively, when the binomial distribution is used to evaluate results. In particular, the exact probability function for the equal allocation method is given as a particular type of mixing distribution, known as a convolution, of binomial probability functions. Regardless of which statistical method is used to test tied data, however, none of the current methods of analysis can account for segmentation or the effect of heterogeneity in individual assessors. To study the possible effect of heterogeneity, the data could first be tested against an identicality norm. Thus, this research clarifies the assumptions that are made when conducting tests on paired comparison data with ties and provides guidance on the choice of analytic method.     

The child care crisis in America.

Argues that for almost 2 decades the American government has recognized the lack of affordable, good quality child care in the US as a serious and pressing problem. Despite this, the US has made very little progress in terms of instituting major reforms in regard to child care. The authors discuss how and why the child care problem in the US has turned to crisis proportions. In addition, they highlight the developmental concerns that surround the issue of child care, and the different child care options currently available for American families to choose from. Finally, they propose a possible solution to this problem; a solution that could carry the US into the 21st century. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of high strength ferritic steel for interconnect application in SOFCs

High-Cr ferritic model steels containing various additions of the refractory elements Nb and/or W were studied with respect to oxidation behaviour (hot) tensile properties, creep behaviour and high-temperature electrical conductivity of the surface oxide scales. Whereas W additions of around 2 wt.% had hardly any effect on the oxidation rates at 800 and 900 °C, Nb additions of 1% led to a substantially enhanced growth rate of the protective surface oxide scale. It was found that this adverse effect can be alleviated by suitable Si additions. This is related to the incorporation of Si and Nb into Laves phase precipitates which also contribute to increased creep and hot tensile strength. The dispersion of Laves phase precipitates was greatly refined by combined additions of Nb and W. The high-temperature electrical conductivity of the surface oxide scales was similar to that of the Nb/W-free alloys. Thus the combined additions of Nb, W and Si resulted in an alloy with oxidation resistance, ASR contribution and thermal expansion comparable to the commercial alloy Crofer 22 APU, but with creep strength far greater than that of Crofer 22 APU.     

On the prediction of the reactor vessel integrity under severe accident loadings (RPVSA)

In order to allow more reliable predictions on the lower head response under core melt-down conditions, the temperature distribution has been analysed including the natural convection in the corium pool. Furthermore, the mechanical models and the failure criteria have been improved based on the RUPTHER and FASTHER experiments where typical temperature gradients are simulated. Lower head local melting as well as corium crust development has been addressed in the CORVIS experiments studying the contact between an alumina/iron thermite and a thick steel plate. The upper head loading by corium impact due to a postulated in-vessel steam explosion has been investigated by the BERDA experiments. Similarity rules were considered such that the results can be directly converted to reactor conditions. Based on these investigations admissible steam explosion energy releases are determined which the upper head can carry. If these limits are not exceeded the reactor containment cannot be endangered by broken head fragments. To provide the necessary basic data, mechanical material tests have been performed.     

Comment on “Linking Cure Process to Adhesive Bulk Strength by Differential Thermal Analysis” J. Adhesion, 25, 185(1988)

Thermal analysis (TA) is practically indispensable to the study and characterisation of modern structural adhesives, particularly those based on epoxies. Because a recent paper in this journal-“Linking Cure Process to Adhesive Bulk Strength by Differential Thermal Analysis” by Jozavi and Sancaktar¹-advocates TA to those familiar with aspects of adhesion other than analysis and chemistry of adhesives, it is more open to comment than is usual.     

Efficacy of praziquantel (0.25 mg kg(-1)) on the cecal tapeworm (Anoplocephala perfoliata) in horses

Aspiration of inflorescence or grass heads (seed head of grasses) often presents with atypical signs and symptoms because grass heads have a tendency to rapidly migrate to the periphery of the lung. If this is not recognized, it can lead to delay in diagnosis and serious complications. Removal with rigid bronchoscopy maybe difficult, and surgery is often needed. We report a case of a seven-month-old child who had a delayed diagnosis of grass head aspiration and subsequently presented with a life threatening tension pneumothorax. This case highlights the importance of obtaining a detailed history in cases of foreign body aspiration and the need to include it in the differential diagnosis of unexplained respiratory symptoms, especially those of sudden onset in children.