18 research outputs found

    Dynamic performance evaluation of ultrasonic composite horn for machining soft and brittle composites

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    Ultrasonic horn (USH) is a key component in high intensity power ultrasonic systems to enhance vibration amplitude at tool end (VATE). Due to high intensity ultrasonic operating frequency of at least , horn may be exposed to high stress levels leading to failure. The primary objective of USH design is to achieve high vibration amplification with good strength. In present research, the effect of fillet radius / roundness on ultrasonic composite horn (USCH) performance was investigated for various materials: stainless steel, aluminum, titanium, and steel, respectively, using finite element analysis (FEA). USCH was developed for ultrasonic machining of soft and brittle composites, especially Nomex honeycomb composite. The important performance parameters considered were longitudinal modal frequency (LMF), Von Mises (VM) stresses, magnification factor (MF), VATE and factor of safety (FS). LMF was found to increase, with decrease in VATE and VM stresses by increasing the roundness at the transition section. Titanium was observed to be highly appropriate material for USCH, because it delivered at least 81.6 % to 142.62 % more vibration amplification and up to 4 times higher factor of safety, consequently, operating life in comparison to other USCH materials

    Thermal performance enhancement of nanofluids based parabolic trough solar collector (NPTSC) for sustainable environment

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    Due to rapid industrialization and urbanization, upward rise in carbon emissions in the atmosphere, and depletion of fossil fuel and gas reserves have forced to find alternative renewable energy resources, where solar energy is one of the most promising source. Parabolic trough solar collectors (PTCs) can effectively transfer high temperature in the tube of receiver upto 400 °C. In this study, Computational Fluid Dynamics (CFD) analysis is used to analyse the effect of multiple working fluids on efficiency of the PTC. Two different types of nanofluids used for analyising the thermal efficiency of PTC through CFD simulations, are Alumina and Copper-oxide nanofluids. The concentration of Copper Oxide and Alumina was kept to 0.01% in the nanofluids. The efficiency for PTC is calculated at two different mass flow rates i.e., 0.0112 Kg/s and 0.0224 Kg/s. The highest efficiency is 13.01 and 13.1% using Al2O3 as nanofluids at 0.0112 Kg/s and 0.0224 Kg/s flow rates, while CuO has an efficiency of 13.92% and 14.79% for these flow rates. The behaviour of absorber tube material on temperature distribution for steel, copper and aluminum as absorber tube material was also investigated. Changing the material from steel to copper and aluminum increased the outlet temperature of the fluid. The maximum output temperature was achieved for copper is 311 K while steel and aluminum showed lower temperature of 307 K and 308 K of the fluid at the outlet. Furthermore, the impact of the receiver tube's length on the working fluid's temperature is also studied. Copper Oxide nanofluid has higher temperature at the outlet for both mass flow rates as compared to alumina nanofluid. Accordingly, a comparison was made for the CFD results with the experimental findings from literature. The nanofluids based PTCs system is promising method for the sustainable environment applications

    Genome-wide analysis of blood lipid metabolites in over 5000 South Asians reveals biological insights at cardiometabolic disease loci.

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    Funder: PfizerFunder: NovartisFunder: National Institute for Health ResearchFunder: MerckBackgroundGenetic, lifestyle, and environmental factors can lead to perturbations in circulating lipid levels and increase the risk of cardiovascular and metabolic diseases. However, how changes in individual lipid species contribute to disease risk is often unclear. Moreover, little is known about the role of lipids on cardiovascular disease in Pakistan, a population historically underrepresented in cardiovascular studies.MethodsWe characterised the genetic architecture of the human blood lipidome in 5662 hospital controls from the Pakistan Risk of Myocardial Infarction Study (PROMIS) and 13,814 healthy British blood donors from the INTERVAL study. We applied a candidate causal gene prioritisation tool to link the genetic variants associated with each lipid to the most likely causal genes, and Gaussian Graphical Modelling network analysis to identify and illustrate relationships between lipids and genetic loci.ResultsWe identified 253 genetic associations with 181 lipids measured using direct infusion high-resolution mass spectrometry in PROMIS, and 502 genetic associations with 244 lipids in INTERVAL. Our analyses revealed new biological insights at genetic loci associated with cardiometabolic diseases, including novel lipid associations at the LPL, MBOAT7, LIPC, APOE-C1-C2-C4, SGPP1, and SPTLC3 loci.ConclusionsOur findings, generated using a distinctive lipidomics platform in an understudied South Asian population, strengthen and expand the knowledge base of the genetic determinants of lipids and their association with cardiometabolic disease-related loci

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome