Ultrasonic fatigue testing of cast steel G42CrMo4 at elevated temperatures

The fatigue life of cast steel G42CrMo4 in two different heat treatment conditions was investigated at room temperature (RT), 473 K and 773 K up to the range of very high cycle fatigue (VHCF), that is, 10⁹ cycles. The fatigue life is determined by casting defects, the hardness of the steel matrix and by temperature. Fatigue life data were discussed in correlation with crack‐initiating defects analysed on fracture surfaces. The SN curves obtained at RT and at 473 K show a large scatter. However, the SN curve at 773 K exhibits a larger slope parameter and a significantly reduced scatter. It is shown that the fatigue behaviour of the cast steel G42CrMo4 changes from 473 to 773 K in the range of VHCF. The fatigue lives of the specimens tested at 773 K were described with a crack growth model.     

Rheological properties of sheeted wheat flour dough measured with large deformations

Abstract

Large deformation rheological properties of a bread dough sheet were compared with baking quality of dough from the same sheet. Both rheological test and baking test could differentiate between dough made from a strong and a weak flour. Apparent viscosity at large deformation appeared to be the best predictor of the minimum sheeting requirement to obtain high loaf volume. This is similar to Mechanical Dough Development (MDD) mixing of dough where the mixing curve (apparent viscosity) is used to determine mixing requirement. Baking tests showed that loaf quality (volume and crumb texture) for bread made with sheeting was different from bread made with MDD mixing, particularly when dough was developed beyond the minimum sheeting requirement. These differences indicate that dough development (or over‐development) by sheeting may occur through a different mechanism than by MDD mixing.     

Bilateral pneumothorax following air bag deployment

Air bags have been shown to decrease mortality from automobile accidents. Herein is a unique case of bilateral pneumothorax following deployment and rupture of an air bag with no other associated chest trauma. One may posit that rupture of the air bag allowed high-pressure gases to be expelled into the patient's lungs resulting in explosive barotrauma.     

Affiliation with Alcoholics Anonymous after treatment: A study of its therapeutic effects and mechanisms of action.

Relatively little is known about how substance abuse treatment facilitates positive outcomes. This study examined the therapeutic effects and mechanisms of action of affiliation with Alcoholics Anonymous (AA) after treatment. Patients (N?=?100) in intensive 12-step substance abuse treatment were assessed during treatment and at 1- and 6-month follow-ups. Results indicated that increased affiliation with AA predicted better outcomes. The effects of AA affiliation were mediated by a set of common change factors. Affiliation with AA after treatment was related to maintenance of self-efficacy and motivation, as well as to increased active coping efforts. These processes, in turn, were significant predictors of outcome. Findings help to illustrate the value of embedding a test of explanatory models in an evaluation study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Accuracy of self-assessment and task performance: Does it pay to know the truth?

An integration of conceptions about attributional antecedents with those of attributional consequences is applied to achievement behavior. The model assumes realistic attributions to be functional. It was tested with a paradigm in which task performance is conceptualized as the sum of the performances on various subtasks requiring different abilities. In Study 1, participants who were induced to make realistic attributions spent more time on tasks for which they had demonstrated high ability than on tasks for which they had demonstrated low ability. This preference for tasks out of areas for which one possesses high ability was correlated with overall performance. Study 2 replicated these results and revealed better posttest performance for individuals with realistic feedback than for individuals with unrealistic feedback. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The African-American Health Project (AAHP): study overview and select findings on high risk behaviors and psychiatric disorders in African American men

The AAHP investigated the neurobehavioral and psychosocial sequelae of HIV-1 and substance use in urban African American men. A community resident sample of 502 African American men stratified by HIV-1 serostatus, drug use and sexual orientation were recruited. A comprehensive battery of measures of neurobehavioral and health status, lifestyle and psychosocial characteristics were administered to all participants, and a stratified sub-sample of 120 participants were tested using state of the art brain imaging techniques to investigate differences in the functional and neurophysiologic effects of HIV-1 and substance use. An overview of the methodology of the AAHP and results on high risk sexual and substance use behaviors, and psychiatric disorders are presented and discussed. The sample was primarily HIV-negative (63%), heterosexual (49% gay or bisexual) and a high percentage used substances during the past year (56% used drugs and 30% moderate/heavy drinkers). High-risk sexual practices were relatively prevalent, and a high percentage reported a history of STDs and other infections. Finally, 25% had a current psychiatric disorder, with gays/bisexuals and HIV-seropositives evidencing greater psychiatric vulnerability. More research is needed to further explore the apparent greater risk for psychiatric disorders among gay and bisexual men, and to determine whether being African American and lower social class exacerbate this risk.     

PCR-ELISA for the early diagnosis of invasive pulmonary aspergillus infection in neutropenic patients

This paper outlines criteria which allow the clinician to identify endodontically treated teeth that can be restored with a high level of predictability. The intent of the article is not to preclude the restoration of teeth that do not meet these criteria; it is to provide a science-based approach for identifying those teeth with a high probability of long-term success upon restoration. For an endodontically treated tooth not requiring a post, the requirements are for biologic width + ferrule length, (i.e. 4.5 mm of supra-bony solid tooth--dentin a minimum of 1 mm thick after preparation). A tooth requiring a post needs, in addition, enough root length to allow a 4 mm apical seal and a post length--apical to the crown margin, equal to the length of the crown. It is essential to assess the functional loads to which the restored tooth would be subjected. Teeth that are endodontically treated, or are likely to be in future, should be avoided as abutments supporting precision attachment RPDs, distal extension RPDs or cantilever FPDs.     

Effects of peroxisome proliferators and/or hypothyroidism on xenobiotic-metabolizing enzymes in rat testis

The objectives of the present work were to study the effects of certain peroxisome proliferators on xenobiotic-metabolizing enzyme activities in the testes of normal and hypothyroid rats, i.e. phenol sulfotransferases (pST), phenol UDP-glucuronosyl transferases (pUDPGT), glutathione transferases (GST), catalase, epoxide hydrolase (EH), glutathione peroxidase (GPX) and NAD(P)H quinone oxidoreductase (QR). Adult male rats (normal and hypothyroid) were treated for 10 days with clofibrate (0.5%), perfluorooctanoic acid (0.5%, PFOA), acetylsalisylic acid (1%, ASA) and di(2-ethylhexyl)phthalate (2%, DEHP) in their diet. The results show that treatment of normal rats with peroxisome proliferators dramatically affects the activities of xenobiotic-metabolizing enzymes (40-60% reduction). The highest effects are seen in catalase activity (50-60% with PFOA and ASA), pUDPGT (55% with PFOA), pST (55% with PFOA) and QR (50% with DEHP). These effects are not seen or are weaker after induction of hypothyroidism. Taken together, it is concluded that different classes of peroxisome proliferators have different effects on rat testicular xenobiotic-metabolizing enzymes.     

Report of the American Society of Nephrology meetings

PURPOSE: We summarize presentations on topics of interest to the pediatric urologist from the annual meeting of the American Society of Nephrology, November 1996. MATERIALS AND METHODS: We reviewed all abstracts submitted for presentation and subsequently published in abstract form. Only those abstracts containing information pertinent to the field of pediatric urology were summarized for this report. RESULTS: A total of 24 abstracts addressing a variety of topics were summarized. Obstructive uropathy was represented by the greatest number of papers and reflects the multiple investigative efforts currently evaluating the cellular aspects of this disorder. The genetic basis of hypercalciuria and the impact of water metabolism on nephroliathisis were also discussed. CONCLUSIONS: Clinical and basic research activities that are of mutual interest to pediatric urologists and nephrologists are being conducted. The topic of obstructive uropathy has received the greatest attention during the last year. However, additional research, potentially collaborative in nature, on topics such as nephroliathisis and reflux nephropathy should be encouraged.     

Three-Dimensional Creep Analyses of the Leaning Tower of Pisa

Three-dimensional creep analyses are carried out to investigate the significance of soil creep effects on the tilting history of the Pisa Tower. Sensitivity analyses of model parameters are also conducted. Results show that three-dimensional creep analysis, although very time-consuming, is necessary in order to obtain more realistic numerical results. Creep effects have been found to account for 1.5 degrees out of the total 5.5 degrees inclination. Creep causes stress states in the clay layers to move away from the critical state line. It was also found that the deformation behaviour of the soil is not sensitive to any specific parameters. This helps to clarify that the total tilting angle of 5.5 degrees cannot be achieved by creeping of the soil. There must be other reasons that also contribute to the tilting of the tower, which cannot be considered by the constitutive model. Nevertheless, the current study could calculate the tilting history of the tower within reasonable accuracy during its construction period and illustrate more or less, the same trend as observed through the last four centuries. The model could also match the observed maximum settlement on top of the upper clay layers extremely well. Therefore, this study provides considerable insight into the deformation history of the soil and the stresses that are likely to exist in the soil.