880 research outputs found

    Teardown analysis of a ten cell bipolar nickel-hydrogen battery

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    Design studies have identified bipolar nickel-hydrogen batteries as an attractive storage option for high power, high voltage applications. A pre-prototype Ni-H2 battery was designed, assembled and tested in the early phases of a concept verification program. The initial stack was built with available hardware and components from past programs. The stack performed well. After 2000 low-earth-orbit cycles the stack was dismantled in order to allow evaluation and analysis of the design and components. The results of the teardown analysis and recommended modifications are discussed

    Nanostructured molybdenum oxides from aluminium-based intermetallic compound: Synthesis and application in hydrogen evolution reaction

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    Characterized by a large surface area to volume ratio, nanostructured metal oxides possess unique chemical and physical properties with applications in electronics, catalysis, sensors, etc. In this study, Mo3Al8, an intermetallic compound, has been used as a precursor to obtain nanostructured molybdenum oxides. It was prepared into ribbons by arc-melting and melt-spinning techniques. Single and double-step free corrosion of the as-quenched material have been studied in 1 M KOH, 1 M HF and 1.25 M FeCl3 at room temperature. In both cases, nanostructured molybdenum oxides were obtained on a surface layer a few microns thick. Two of the as-prepared samples were tested for their electrocatalytic capability for hydrogen evolution reaction (HER) in 0.5 M H2SO4 giving low onset potential (−50 mV, −45 mV), small Tafel slopes (92 mV dec−1, 9 mV dec−1) and high exchange current densities (0.08 mA cm−2, 0.35 mA cm−2 respectively). The proposed nanostructured molybdenum oxides are cost-effective and sustainable due to the cheap and abundant starting material used and the simple synthetic route, paving the way for their possible application as HER electrocatalysts

    Synthetic bone grafting in aseptic loosening of acetabular cup: Good clinical and radiological outcomes in contained bone defects at mediumterm follow up

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    Restoring bone loss is one of the major challenges when facing hip revision surgery. To eliminate the risk of disease transmission and antigenicity of allografts and donor-morbidity of autografts, the use of synthetic bioceramics has become popular in the last decade. Our study investigated the effectiveness of impaction bone grafting (IBG) of contained acetabular defects (Paprosky 2 and 3a) using a porous ceramic-based hydroxyapatite bone substitute (Engipore, provided by Finceramica Faenza S.p.A., Faenza, Italy) mixed with a low percentage of autologous bone (obtained from reaming when available). We retrospectively assessed 36 patients who underwent acetabular revision using IBG using a porous ceramic-based hydroxyapatite bone substitute with cementless implants with a mean follow-up of 4.4 years. We evaluated, at regular intervals, patients clinically (using the Hip Harris Score and Oxford Score) and radiologically to evaluate the rate of incorporation of the graft, the presence of radiolucent lines or migrations of the cup. Clinical scores significantly improved (WOMAC improved from 49.7–67.30, and the HSS from 56–89). The rate of implants’ survival was 100% at our medium follow-up (4.4 years). We reported five cases of minor migration of the cup, and radiolucent lines were visible in seven patients at the last-follow up. The graft was well-incorporated in all patients. The results presented in this study suggest the HA bone substitute is an effective and safe bone graft when facing hip revision surgery; thus, longer follow-up studies are required

    Treatability of digested piggery/poultry manure by anammox bacteria

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    The liquid fraction of digested material is rich in ammonium and may require nitrogen removal. The aim of this research was to evaluate the applicability of the anammox process for the biological N removal from a supernatant coming from the anaerobic digestion of a mixture of piggery manure, poultry manure, and of agro-wastes. The supernatant was pre-treated in a partial nitritation pilot-scale reactor located at the farm. A batch procedure for testing the short term effect of high-strength wastewaters on anammox activity is presented. The anammox process was successfully applied for the first time to undiluted digestate, and the average N removal efficiency achieved during 350 days of experimentation in a SBR lab-scale reactor was 91%

    Exposition of St. Francis Xavier’s Holy Relics in Goa: An Importance-Performance Analysis

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    Pilgrimage Tourism, one of the oldest forms of travelling, is the largest tourism sector in India; annually more than 70% of domestic tourist movement is for religious purposes which comes to 250 million pilgrims (Jachowski, 2000, Singh, 2016) and accounts for 20% of the revenue generated in the tourism industry (Dewan et al., 2008), hence, making it significant religiously, economically, politically, as well as sociologically. The present study was based on a survey conducted among the visitors who came for the 17th Exposition of St Francis Xavier’s holy relics, a Christian religious event, from 22nd November 2014 to 4th January 2015. Firstly, we discuss whether there is any association between the two groups of travellers (religious only Vs religious plus other travel motivations) and their demographic characteristics. Secondly, an attempt is made to explore the possibility of identifying latent motivational factors. Next, testing is done to find out whether there is any significant difference in motivational factors (Tsai et al., 2002) across various demographic characteristics of the combined visitors. Finally, the paper identifies the gap with respect to various facilities available for tourism, based on what the visitors perceived before visiting and what they experienced afterwards. It was found that demographically there is no difference between those who are coming specifically for religious purpose Vs those coming for religious and other purposes. Results also allowed the categorising of latent motivational factors and finding that demographically there is no difference except for age (working class) with respect to escape from busy life. With respect to the various tourism facilities, it was found that the quantified results exactly match with the qualitative findings of Wilson (1997); almost all of the facilities experienced by the visitors are falling under the A-Quadrant, where serious improvements need to be made. It can be concluded that there are many grey areas where timely actions from various tourism stakeholders is urgently required to maintain a consistent and positive image before the ‘experience’ becomes less attractive

    Transforming growth factor β1 T29C gene polymorphism and hypertension: Relationship with cardiovascular and renal damage

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    Distribution of T29C TGFβ1 gene polymorphism was analysed in 260 hypertensive and 134 normotensive subjects. Circulating TGFβ1 and procollagen type III levels, microalbuminuria, left ventricular geometry and function were evaluated in all the hypertensives subgrouped according to T29C TGFβ1 gene polymorphism. Circulating TGFβ1 by ELISA technique, procollagen type III by a specific radioimmunoassay, microalbuminuria by radioimmunoassay, left ventricular geometry and function by echocardiography were determined. All groups were comparable for gender, age and sex. Regarding T29C TGFβ1 gene polymorphism, prevalence of TC or CC genotypes was significantly (p < 0.05) higher in hypertensives than normotensives. TC and CC hypertensives were characterized by a higher prevalence of subjects with microalbuminuria (p < 0.001 TC vs TT; p < 0.05 CC vs TT), left ventricular hypertrophy (p < 0.01 TC and CC vs TT), and by increased levels of procollagen type III (p < 0.05 TC and CC vs TT). TC hypertensives were also characterized by a significant increase (p < 0.05) of LVM and LVM/h2.7 and of urinary albumin excretion (p < 0.05) values than those detectable in TT hypertensives. Our data suggest that T29C TGFβ1 gene polymorphism was associated to clinical characteristics suitable to recognize hypertensives with a higher severity of hypertension

    Early carotid atherosclerosis and cardiac diastolic abnormalities in hypertensive subjects

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    Despite the fact that it is known that hypertension may be associated to early atherosclerosis manifestations, few data are to date available on the relationship between early carotid abnormalities and left ventricular diastolic dysfunction. To address this issue, 142 hypertensive patients (64 females and 78 males) younger than 55 years, at the first diagnosis of mild-to-moderate essential hypertension (WHO/ISH criteria), were selected from a database consisting of 3541 subjects referred to ultrasound cardiovascular laboratory in the last 5 years. Carotid intima-media thickness (IMT) was detected by high-resolution vascular ultrasound and left ventricular structure and function by the use of Doppler echocardiography. According to carotid IMT values, all patients were subgrouped into two groups consisting of 89 (62.6%) pts with IMT > or = 1 mm (A) and 53 (37.4%) pts with IMT < 1 mm (B). Our results show that isovolumic relaxation time (IVRT), deceleration time of E velocity (EDT) and left ventricular relative wall thickness (LV-RWT) were significantly (P < 0.05) higher in group A (IVRT 112 +/- 8.9 ms; EDT 288 +/- 21.8 ms; LV-RWT 0.40 +/- 0.08) than in group B (IVRT 92.3 +/- 4.6 ms; EDT 203.3 +/- 27.01 ms; LV- RWT 0.37 +/- 0.06). Moreover, the prevalence of left ventricular hypertrophy (LVH) was significantly (P < 0.01) higher in group A (30/89; 33.7%) than in group B (8/53; 15%). A positive correlation (P < 0.001) between IMT, EDT and IVRT was found only in hypertensives without LVH. These results are consistent with the indication that IMT evaluation has to be recommended both in hypertensive patients with LVH and in those without LVH, but with left ventricular diastolic dysfunction. This approach might improve the prognostic stratification of hypertensive subjects and it might be suitable to recognize the subset of patients at a higher risk of cardiovascular disease or events early

    Effects of moderate Sicilian red wine consumption on inflammatory biomarkers of atherosclerosis.

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    Objective: The aim of the study is to evaluate the effect of moderate Sicilian red wine consumption on cardiovascular risk factors and, in particular, on some inflammatory biomarkers. Methods: A total of 48 subjects of both sexes who were nondrinkers or rare drinkers of moderate red wine were selected randomly subdivided into two groups assigned to receive with a crossover design a Sicilian red wine (Nero d\u2019Avola or Torrepalino) during meals: Group A (n 24), in whom the diet was supplemented for 4 weeks with 250 ml/day of red followed by 4 weeks when they returned to their usual wine intake; and Group B (n 24), in whom the usual wine intake maintained for 4 weeks, followed by 4 weeks when the diet was supplemented with 250 ml/day of red wine. The following values measured in all tests: blood glucose, total and HDL-cholesterol and triglycerides, LDL-cholesterol, LDL/HDL apolipoproteins A1 and B, Lp(a), plasma C-reactive protein, TGFb1, D-Dimer, Factor VII , PAI Ag, t-PA Ag, fibrinogen, oxidized LDL Ab, total plasma antioxidant capacity. Results: At the end of the red wine intake period, LDL/HDL, fibrinogen, factor VII, plasma C-reactive protein and oxidized Ab were significantly decreased, while HDL-C, Apo A1,TGFb1, t-PA, PAI and total plasma antioxidant capacity were significantly increased. Conclusions: Our results show a positive effect of two Sicilian red wines on many risk factors and on some inflammatory biomarkers, suggesting that a moderate consumption of red wine in the adult population is a positive component of Mediterranean diet
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