Full scale phosphoric acid fuel cell stack technology development

The technology development for phosphoric acid fuel cells is summarized. The preparation, heat treatment, and characterization of carbon composites used as bipolar separator plates are described. Characterization included resistivity, porosity, and electrochemical corrosion. High density glassy carbon/graphite composites performed well in long-term fuel cell endurance tests. Platinum alloy cathode catalysts and low-loaded platinum electrodes were evaluated in 25 sq cm cells. Although the alloys displayed an initial improvement, some of this improvement diminished after a few thousand hours of testing. Low platinum loading (0.12 mg/sq cm anodes and 0.3 mg/sq cm cathodes) performed nearly as well as twice this loading. A selectively wetproofed anode backing paper was tested in a 5 by 15 inch three-cell stack. This material may provide for acid volume expansion, acid storage, and acid lateral distribution

NDE detectability of fatigue type cracks in high strength alloys

Specimens suitable for investigating the reliability of production nondestructive evaluation (NDE) to detect tightly closed fatigue cracks in high strength alloys representative of those materials used in spacecraft engine/booster construction were produced. Inconel 718 was selected as representative of nickel base alloys and Haynes 188 was selected as representative of cobalt base alloys used in this application. Cleaning procedures were developed to insure the reusability of the test specimens and a flaw detection reliability assessment of the fluorescent penetrant inspection method was performed using the test specimens produced to characterize their use for future reliability assessments and to provide additional NDE flaw detection reliability data for high strength alloys. The statistical analysis of the fluorescent penetrant inspection data was performed to determine the detection reliabilities for each inspection at a 90% probability/95% confidence level

Strontium Isotope Composition and Trace Element Concentrations in Lake Huron and its Principal Tributaries

(print) ix, 109 p. : ill., maps ; 28 cm.Concentrations of the major cations: Na, K, Ca, Mg and Sr were determined for 64 samples of surface water from Lake Huron and for 17 of its major tributary rivers. For addition, isotopic compositions of strontium were measured for 30 samples of lake water and for 13 of the tributary rivers. Concentrations of dissolved iron and total phosphorus were determined for a small suite of lake and river water. The data document important differences in the chemical composition of water discharged into Lake Huron by Lake Superior, Lake Michigan and tributary rivers. These differences are related to differences in the chemical and mineralogical composition of the bedrock underlying the Great Lakes drainage basin. The strontium contributed to Lake Huron by water draining the Canadian Shield along its northern shore is enriched in radiogenic Sr87. The average Sr87/ Sr86 ratio is 0. 718. The rivers draining sedimentary rocks of Michigan and southwestern Ontario contribute strontium whose isotope composition is similar to that in the modern oceans and has a Sr87/Sr86 ratio of 0.710. A geochemical model is presented which attempts to represent the chemical composition of water in Lake Huron as a mixture of the different types of water discharged by different sources.Abstract -- Statement of the Significance and Applicability of the Results -- Table of Contents -- List of Tables -- List of Figures -- Acknowledgments -- Introduction -- Collection of Water Samples -- Analytical Methods -- Precision and Accuracy -- Presentation and Discussion of the Results -- Formulation of a Model for the Chemical Composition of Lake Huron -- The Isotope Composition of Strontium in the Great Lakes -- Summary and Conclusions -- References -- Geochemical Aspects of the Scioto and Olentangy Rivers, Columbus, Ohi

A tandem duplication within the fibrillin 1 gene is associated with the mouse tight skin mutation.

Mice carrying the Tight skin (Tsk) mutation have thickened skin and visceral fibrosis resulting from an accumulation of extracellular matrix molecules. These and other connective tissue abnormalities have made Tskl + mice models for scleroderma, hereditary emphysema, and myocardial hypertrophy. Previously we localized Tsk to mouse chromosome 2 in a region syntenic with human chromosome 15. The microfibrillar glycoprotein gene, fibrillin 1 (FBN1), on human chromosome 15q, provided a candidate for the Tsk mutation. We now demonstrate that the Tsk chromosome harbors a 30- to 40-kb genomic duplication within the Fbn1 gene that results in a larger than normal in-frame Fbn1 transcript. These findings provide hypotheses to explain some of the phenotypic characteristics of Tskl + mice and the lethality of Tsk/Tsk embryos

Deliberate Apprenticeship in the Pediatric Emergency Department Improves Experience for Third-year Students

INTRODUCTION: The Pediatric Emergency Department (PED) provides medical students with learning in a high-volume, fast-paced environment; characteristics that can be stressful for new students. Shadowing can improve transitioning, yet this alone does not facilitate students’ development of independent medical care competencies. This study evaluates if third-year medical students’ deliberate apprenticeship with senior residents increases students’ comfort and patient exposure in the PED. METHODS: This study took place over the 2011-2012 academic year, and study participants were all third-year medical students during their pediatric clerkship rotation. This was a prospective educational intervention assigning students to randomized control blocks of deliberate apprenticeship (DA) intervention or control. DA students were paired with a senior resident who oriented and worked with the student, while control students were unpaired. All students completed a 20-question structured survey at shift end, which included questions about their perception of the learning environment, comfort with, and number of patient care responsibilities performed. We used independent Mann-Whitney and t-tests to compare experiences between the groups. Statistical significance was defined as p<0.05. We used the constant comparative method to qualitatively analyze students’ comments. RESULTS: Response rate was 85% (145/169). Students also rated on 5-point Likert-scale their level of comfort with defined aspects of working in the PED. DA students (n=76) were significantly more comfortable obtaining histories (4.2 versus 3.8) and formulating differential diagnoses (3.9 versus 3.4). DA students also performed more physical exams (2.9 versus 2.4). We categorized themes from the qualitative analysis of the students’ comments about their PED experience. The titles for these themes are as follows: PED provides a good learning experience; uncertainty about the medical student’s role in the PED; third-year medical students compete with other learners for teaching attention; opportunities provided to medical students for inclusion in patient care; personal knowledge deficits limit the ability to participate in the PED; PED pace affects learning opportunities. CONCLUSION: DA constitutes a feasible approach to the clinical learning environment that increases students’ patient care experiences and may ease transitioning for undergraduate medical students to new clinical environments

Amelioration of bleomycin-induced lung fibrosis in hamsters by dietary supplementation with taurine and niacin: biochemical mechanisms.

Interstitial pulmonary fibrosis induced by intratracheal instillation of bleomycin (BL) involves an excess production of reactive oxygen species, unavailability of adequate levels of NAD and ATP to repair the injured pulmonary epithelium, and an overexuberant lung collagen reactivity followed by deposition of highly cross-linked mature collagen fibrils resistant to enzymatic degradation. In the present study, we have demonstrated that dietary supplementation with taurine and niacin offered almost complete protection against the lung fibrosis in a multidose BL hamster model. The mechanisms for the protective effect of taurine and niacin are multifaceted. These include the ability of taurine to scavenge HOCl and stabilize the biomembrane; niacin's ability to replenish the BL-induced depletion of NAD and ATP; and the combined effect of taurine and niacin to suppress all aspects of BL-induced increases in the lung collagen reactivity, a hallmark of interstitial pulmonary fibrosis. It was concluded from the data presented at this Conference that the combined treatment with taurine and niacin, which offers a multipronged approach, will have great therapeutic potential in the intervention of the development of chemically induced interstitial lung fibrosis in animals and humans

An Evaluation Of The Prospects For The Euro Currency In 2012-2013

The 2008 global Financial Crisis and the subsequent relative collapse of the financial and economic markets, including the government bond markets, in Greece, Ireland, and Portugal as well as economic weakness in other Western European economies have called into question the viability, going forward, of the Euro Currency. The so called PIIGS countries of Portugal, Ireland, Italy, Greece, and Spain are thought to be financially vulnerable because of high levels of government spending and resulting deficit levels and inefficient labor markets and tax collection policies among other factors. Those five countries, along with the stronger economies of France and Germany, comprise 7 of the 17 countries in the Eurocurrency Union. Any weakness in the 5 country group can have a contagion effect on the rest and if the recent financial bailouts by the IMF and the European Central Bank in Greece, Portugal and Ireland are not effective then there is a real danger that one of more of the GIP (Greece, Ireland and Spain) countries may have to abandon or be forced to abandon the Euro. Because there is no provision for a country leaving the Eurocurrency Union this is uncharted territory and could lead to the weakening or even demise of the Euro depending upon circumstances. The fact that there are also significant financial linkages and related default risk connecting the five countries to the sounder economies of Germany and France increases the risks. This paper will evaluate the likelihood that the Eurocurrency will be substantially weakened or abandoned over the next 18 months. The evaluation will be highly dependent upon the forecasts for the 5 countries economic prospects, especially the very large economies of Italy and Spain as well as the likely responses of Germany and France to future default like events in the five countries. Metrics utilized will include the trend in economic indicators like long term government bond yields, deficit spending, tax collections, economic growth, and financial linkages and dependence among the seven countries. European Central Bank data and information from related sources like the IMF will be utilized