Free-piston Stirling engine conceptual design and technologies for space power, phase 1

As part of the SP-100 program, a phase 1 effort to design a free-piston Stirling engine (FPSE) for a space dynamic power conversion system was completed. SP-100 is a combined DOD/DOE/NASA program to develop nuclear power for space. This work was completed in the initial phases of the SP-100 program prior to the power conversion concept selection for the Ground Engineering System (GES). Stirling engine technology development as a growth option for SP-100 is continuing after this phase 1 effort. Following a review of various engine concepts, a single-cylinder engine with a linear alternator was selected for the remainder of the study. The relationships of specific mass and efficiency versus temperature ratio were determined for a power output of 25 kWe. This parametric study was done for a temperature ratio range of 1.5 to 2.0 and for hot-end temperatures of 875 K and 1075 K. A conceptual design of a 1080 K FPSE with a linear alternator producing 25 kWe output was completed. This was a single-cylinder engine designed for a 62,000 hour life and a temperature ratio of 2.0. The heat transport systems were pumped liquid-metal loops on both the hot and cold ends. These specifications were selected to match the SP-100 power system designs that were being evaluated at that time. The hot end of the engine used both refractory and superalloy materials; the hot-end pressure vessel featured an insulated design that allowed use of the superalloy material. The design was supported by the hardware demonstration of two of the component concepts - the hydrodynamic gas bearing for the displacer and the dynamic balance system. The hydrodynamic gas bearing was demonstrated on a test rig. The dynamic balance system was tested on the 1 kW RE-1000 engine at NASA Lewis

Protein expression of the epsilon subspecies of protein kinase C ceases as Swiss 3T6 fibroblasts increase in cell density even though message for the protein is still present

AbstractWe have noted previously that growth of C6 glioma cells from low cell density to confluency and quiescence in serum is accompanied by changes in protein content of different protein kinase C (PKC) subspecies. Here we show that the same occurs as non-contact-inhibiting Swiss 3T6 fibroblasts grow to high density in the presence of serum. Protein expression of PKC subspecies α and δ increases as the cells increase in density while that of PKC-ζ remains the same. Unusally, protein expression of PKC-ϵ is completely down-regulated as cells grow beyond about 50% confluency and no PKC-ϵ protein can be detected in 3T6 fibroblasts at high density by Western blotting. However, mRNA for PKC-ϵ is expressed at all stages of fibroblast growth as revealed by RT-PCR. When high-density 3T6 fibroblasts are passaged to low density in fresh medium, re-expression of PKC-ϵ protein is observed within 15 min and becomes down-regulated again as cells become more dense. This very rapid synthesis of PKC-ϵ is not blocked by the transcription inhibitor actinomycin D but is inhibited by cycloheximide. PKC-ϵ has some characteristics of a novel `early response' protein whose synthesis in newly passaged 3T6 cells is regulated at the translational level

Building an Electronic Learning Community: From Design to Implementation

The University of Maryland at College Park in cooperation with Baltimore City Public Schools and several partners is working to build an electronic learning community that provides teachers with multimedia resources that are linked to outcome-oriented curriculum guidelines. The initial resource library contains over 1000 videos, texts, images, web sites, and instructional modules. Using the current system, teachers can explore and search the resource library, create and present instructional modules in their classrooms, and communicate with other teachers in the community. This paper discusses the iterative design process and the results of informal usability testing. Lessons learned are also presented for developers. (Also cross-referenced as UMIACS-TR-97-67 and as CLIS-TR-97-12

Clinical Applications of Attractor Reconstruction Analysis

This poster was presented at the Science and Engineering Impact Showcase, King's College London, 4th April 2017

Prognostic importance of tissue velocity imaging during exercise echocardiography in patients with systolic heart failure

Resting echocardiography measurements are poor predictors of exercise capacity and symptoms in patients with heart failure (HF). Stress echocardiography may provide additional information and can be expressed using left ventricular ejection fraction (LVEF), or diastolic parameters (E/E′), but LVEF has some major limitations. Systolic annular velocity (S′) provides a measure of longitudinal systolic function, which is relatively easy to obtain and shows a good relationship with exercise capacity. The objective of this study was to investigate the relationship among S′, E/E′ and LVEF obtained during stress echocardiography and both mortality and hospitalisation. A secondary objective was to compare S′ measured using a simplified two-wall model. A total of 80 patients with stable HF underwent exercise stress echocardiography and simultaneous cardiopulmonary exercise testing. Volumetric and tissue velocity imaging (TVI) measurements were obtained, as was peak oxygen uptake (VO(2) peak). Of the total number of patients, 11 died and 22 required cardiac hospitalisation. S′ at peak exertion was a powerful predictor for death and hospitalisation. Cut-off points of 5.3 cm/s for death and 5.7 cm/s for hospitalisation provided optimum sensitivity and specificity. This study suggests that, in patients with systolic HF, S′ at peak exertion calculated from the averaged spectral TVI systolic velocity of six myocardial segments, or using a simplified measure of two myocardial segments, is a powerful predictor of future events and stronger than LVEF, diastolic velocities at rest or exercise and VO(2) peak. Results indicate that measuring S′ during exercise echocardiography might play an important role in understanding the likelihood of adverse clinical outcomes in patients with HF

AFP, PIVKAII, GP3, SCCA-1 and follisatin as surveillance biomarkers for hepatocellular cancer in non-alcoholic and alcoholic fatty liver disease

<p>Abstract</p> <p>Background</p> <p>The incidence and mortality of hepatocellular cancer (HCC) complicating alcoholic and non-alcoholic fatty liver diseases (ALD and NAFLD) is rising in western societies. Despite knowing the at risk populations for HCC development, the lack of sensitive and specific means of surveillance hampers disease detection at curable stages. The most widely used serum HCC marker is alpha-fetoprotein (AFP), while PIVKA-II, glypican-3 (GP3) and Squamous Cell Carcinoma Antigen -1 (SCCA-1) have been proposed as new biomarkers. Assessment of these HCC biomarkers has largely been performed in patients with viral hepatitis. We conducted a cross sectional study assessing the value of these serum proteins, as well a novel candidate biomarker -follistatin – in patients with HCC arising on a background of ALD or NAFLD.</p> <p>Methods</p> <p>Pre-treatment serum samples from 50 patients with HCC arising on a background of ALD (n = 31) or NAFLD (n = 19) were assessed by specific ELISA assay for PIVKAII, Glypican-3, SCCA-1 and Follistatin. Results were compared and contrasted with a control patient group with biopsy proven steatohepatitis-related cirrhosis (n = 41). The diagnostic accuracy of each of the candidate biomarkers was evaluated using receiver operating characteristic (ROC) curve analysis, reporting the area under the curve (AUC) and its 95% confidence interval (CI). Performance was compared to that of the established biomarker, AFP.</p> <p>Results</p> <p>Serum levels of all proteins were assessed by specific ELISA assays. GP3, SCCA-1 and follistatin had no HCC surveillance benefit in these patients. AFP and PIVKAII were superior to the other markers, particularly in combination.</p> <p>Conclusion</p> <p>We conclude that while novel means of surveillance are urgently required, the combination of AFP and PIVKAII for HCC is an improvement on AFP alone in ALD/NAFLD patients. Furthermore, our data in this homogenous subset of patients- particularly that confirming no role for SCCA-1 – suggests that the choice of optimal biomarkers for HCC surveillance may be determined by the aetiology of underlying chronic liver disease.</p

Compulsory Arbitration Agreements in Domestic and International Consumer Contracts

This paper examines the UK Unfair Terms in Consumer Contracts Regulations (UTCCR)'s prohibition on clauses in consumer contracts that mandate dispute settlement in an arbitration tribunal as potentially unfair and oppressive as against consumers because it denies their right to civil adjudication. The understanding of UTCCR's unfairness as developed by the UK House of Lords is not necessarily applicable to arbitration clauses because of the lower cost of such proceedings and the availability of legal aid, even in the international context. International arbitration decisions may also be reviewed for procedural irregularities under the New York Convention. Various European court decisions are reviewed where compulsory arbitration clauses in consumer contracts were evaluated for fairness to conclude that courts should be more receptive to such terms because of procedural advantages that they may accord to consumers