Multidimensional flow,thermal, and chemical behavior in solid-oxide fuel cell button cells

The quantitative analysis and interpretation of button-cell experiments usually depends upon assuming isothermal conditions together with uniform and known gas composition within the gas compartments. An objective of the present effort is to develop computational tools to study the validity of such assumptions. A three-dimensional computational fluid dynamics (CFD) model is developed and applied to a particular SOFC button cell, characterizing the fluid flow, chemistry, and thermal transport. Results show that when inlet flow rates are sufficiently high, button-cell data can be interpreted using the commonly used assumptions. However, when flow rates are not sufficient, the assumptions of uniform composition can be significantly violated. Additionally, depending on operating conditions there can be significant temperature variations within the gas compartments and the membrane–electrode assembly.     

In pursuit of wellness: The self-care imperative.

The practice of psychology can be demanding, challenging, and emotionally taxing. Failure to adequately attend to one's own psychological wellness and self-care can place the psychologist at risk for impaired professional functioning. An ongoing focus on self-care is essential for the prevention of burnout and for maintaining one's own psychological wellness. Salient aspects of self-care are discussed, including the ethical imperative of addressing self-care throughout one's career. Three invited expert commentaries provide additional insights and recommendations on positive actions, preventive strategies, and steps to be taken by individual psychologists, by those training the next generation of psychologists, and by professional associations. Realities of the current state of psychology and a clear call for action are highlighted, with the overarching goal being the ethical and effective treatment of clients and the successful management of the challenges and stresses faced by practicing psychologists. Baker, Elman, and Schoener provide commentaries on the initial article by Barnett. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluating alternative economic growth rates and land use policies for Flathead County, Montana

Nine alternative futures are simulated for Flathead County, Montana for 2000–2014 and 2000–2024. Alternative futures incorporate high, moderate, and low growth rates, and baseline (current), moderately restrictive, and highly restrictive land use policies. Increases in employment are estimated using the IMPLAN regional economic model and translated into acreage requirements for commercial–institutional–industrial (CI&I) units and six types of housing units. Conversion of developable parcels to CI&I and housing units is based on a multiple-criteria score that measures the suitability of developable parcels for various developed uses. Additional jobs and housing units needed to support those jobs increase substantially, particularly for the moderate and high growth rates. Total acreage required for CI&I and housing units exceeds the acreage available for development for the baseline policy with the moderate and high growth rates, and for the moderately restrictive policy with high growth rates. There are no land shortages with any of the growth rates for the highly restrictive land use policy. Moderate and high growth can be sustained through 2024 in Flathead County by implementing a moderately restrictive land use policy if growth rates are moderate, and a highly restrictive land use policy if the growth rates are high.     

Informed consent: Too much of a good thing or not enough?

Informed consent is an essential aspect of the establishment of every professional relationship in which psychologists participate. When done effectively, it helps promote other individuals' autonomy, engages them in a collaborative process, and helps to reduce the likelihood of exploitation or harm, among a number of potential benefits. Yet, a number of challenges and dilemmas relevant to informed consent exist for psychologists. Three invited experts provide commentaries on issues raised, questions asked, and dilemmas posed that will, the authors hope, fully stimulate further consideration and discussion of these important issues. The commentaries also broaden the discussion of informed consent in all roles in which psychologists serve. Specific recommendations are made for practicing psychologists for the ethical and effective application of informed consent in their work. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Remaining life assessment of carbon steel boiler headers by repeated creep testing

The condition of carbon steel boiler headers that have been in service for over 25 years has been assessed periodically by NDT, dimensional measurements, replication and accelerated creep testing. Historical temperature records were limited, so estimates of effective header temperatures were made from replicas. These estimates were compared with header stub thermocouple readings. At about 280,000 service hours, samples were chain-drilled from the headers for accelerated creep testing. These test results indicated that the headers had satisfactory remaining life. Nine years after the original samples were taken, additional samples were removed from one header at 337,000 service hours. The creep rupture properties measured from the repeated tests were almost identical to the initial results. A mild degree of random, nodular graphite was found in the samples and its effect on creep properties is discussed.     

Microstructural features of rolled Mg-3Al-1Zn

The microstructures of hot- and cold-rolled Mg-3Al-1Zn (AZ31) are examined using scanning electron and optical microscopy. It is shown that the microstructures following multipass hot rolling and annealing are more uniform than those formed by heavy single pass rolling and annealing. The importance of twins in producing intragranular recrystallization is evident, although the most dominant nucleation site is grain boundaries. The cold-rolled structure after a rolling reduction of 15 pct is dominated by the presence of deformation twins. Twin trace analysis suggests that approximately two thirds of the twins are a form of “c-axis compression” twin. A number of “c-axis tension” twins were also observed and additional in-situ scanning electron microscopy experiments were performed to confirm earlier observations that suggest these twins can form after deformation, during unloading. This article is based on a presentation made in the symposium entitled “Phase Transformations and Deformation in Magnesium Alloys,” which occurred during the Spring TMS meeting, March 14–17, 2004, in Charlotte, NC, under the auspices of ASM-MSCTS Phase Transformations Committee.     

The effects of coculture with autologous cryopreserved endometrial cells on human in vitro fertilization and early embryo morphology: a randomized study

PURPOSE: The aim of this study was to examine the influence of endometrial cells on the fertilization rate and early embryonic morphology following routine in vitro fertilization (IVF). Cryopreservation with subsequent thawing allowed the use of autologous somatic cells, thus minimizing the risk of transmission of infective agents. Interpatient variability was eliminated by randomizing oocytes from each cycle into the control or coculture group. RESULTS: Two hundred ninety-four oocytes from 24 IVF cycles (21 patients) were included in the study (145 coculture and 149 control). The normal fertilization rate of control oocytes (56.4%) was not significantly different from that of oocytes cocultured with endometrial cells (61.4%). The mean number of blastomeres in cocultured embryos (3.65) was not significantly different from the number in control embryos (3.46) 2 days after insemination, but the proportion of embryos with minimal or no fragmentation was significantly higher in the coculture group [34/84 (40.5%) vs. 17/80 (21.3%); P < 0.01]. CONCLUSIONS: The inclusion of cryopreserved autologous endometrial cells in routine clinical IVF procedures does not influence fertilization or the early cleavage rate but may reduce the extent of embryo fragmentation during the early cleavage divisions.     

Problem solving and intervention design: Guidelines for the evaluation of technical adequacy.

Describes suggested guidelines for evaluating the technical adequacy of problem solving and intervention design. The problem- solving process, viewed as a structural aspect of validity, provides an overarching set of rules through which assessment information is transformed into professional inferences, actions, and outcomes. The article defines key concepts, including decision making, consequences, and problem solving. These concepts are then used to illustrate potential points of analysis for each step of the problem-solving process, including problem identification, problem analysis, plan development and implementation, and plan evaluation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acute renal failure in infants, children and adults

Acute renal failure (ARF) occurs in many critically ill patients regardless of age. A combination of events often seen in critical care settings, including shock, sepsis, hypoxia, and the use of potentially nephrotoxic medications, combine to make ARF an ongoing and important management issue in critical care medicine. Since the events leading to the development of ARF differ in infants, children, adults, and the elderly, the pathophysiology, clinical features, and treatment modalities do indeed have remarkable similarities among the different age groups.     

Regionally specific pattern of neurochemical pathology in schizophrenia as assessed by multislice proton magnetic resonance spectroscopic imaging

OBJECTIVE: Several single-voxel proton magnetic resonance spectroscopy (1H-MRS) studies of patients with schizophrenia have found evidence of reductions of N-acetyl-aspartate (NAA) concentrations in the temporal lobes. Multislice proton magnetic resonance spectroscopy imaging (1H-MRSI) permits simultaneous acquisition and mapping of NAA, choline-containing compounds (CHO), and creatine/phosphocreatine (CRE) signal intensities from multiple whole brain slices consisting of 1.4-ml single-volume elements. We have used 1H-MRSI to assess the regional specificity of previously reported changes of metabolite signal intensities in schizophrenia. Hippocampal volume was also measured to test the relationship between 1H-MRSI findings and tissue volume in this region. METHOD: Ratios of areas under the metabolite peaks of the proton spectra were determined (i.e., NAA/CRE, NAA/CHO, CHO/CRE) for multiple cortical and subcortical regions in 10 inpatients with schizophrenia. RESULTS: Patients showed significant reductions of NAA/CRE and NAA/CHO bilaterally in the hippocampal region and in the dorsolateral prefrontal cortex. There were no significant changes in CHO/CRE or in NAA ratios in any other area sampled. No significant correlation was found between metabolite ratios in the hippocampal region and its volume. CONCLUSIONS: NAA-relative signal intensity reductions in schizophrenia appear to be remarkably localized, involving primarily the hippocampal region and the dorsolateral prefrontal cortex, two regions implicated prominently in the pathophysiology of this disorder.