2,060 research outputs found

    Thin Film Solar Cells: Fabrication, Characterization and Applications

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    Metabolic regulation during sport events: factual interpretations and inadequate allegations

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    .Different fuels are available to generate ATP for muscle activities during sport events. Glycogen from striated muscles and liver stores may be converted to lactic acid or almost completely oxidized to carbon dioxide (CO2), triacylglycerol within the muscle itself and fatty acids from adipose tissue could be converted to CO2 in acting muscles, some free amino acids can be released within the muscle itself and from intestinal stores to sustain the amount of ATP generation indispensable for muscle contraction. All single biochemical reactions, but one, need one or several enzymes to activate the conversion of a substrate into a product. The energy transformation in biochemical reactions is led by application of so-called free energy. Reversible and non-reversible reactions within a metabolic pathway are dependent on specific enzymes near or far from equilibrium. Allosteric enzymes are regulatory enzymes that provide the direction in the pathway. A regulatory enzyme is either activated or inhibited by small regulators (ligands). A reversible substrate cycle between A and B is catalyzed by two enzymes with different fluxes. The need of ATP production for muscle contraction is under the leadership of regulatory enzymes and available substrate stores. The improvement of adapted metabolic reactions under sport training depends on the appropriate increase of regulatory enzymes within the glycolytic and oxidative pathways. The amount of some specific enzymes is increased by training in order to improve the maximum activity of the metabolic pathway. Unfortunately, several publications do not precisely implicate the appropriate enzyme(s) to explain or reject the adaptation induced by the training schedule. A few examples will illustrate the factual interpretation and the inadequate allegation

    Metabolic regulation during sport events: factual interpretations and inadequate allegations

    Get PDF
    .Different fuels are available to generate ATP for muscle activities during sport events. Glycogen from striated muscles and liver stores may be converted to lactic acid or almost completely oxidized to carbon dioxide (CO2), triacylglycerol within the muscle itself and fatty acids from adipose tissue could be converted to CO2 in acting muscles, some free amino acids can be released within the muscle itself and from intestinal stores to sustain the amount of ATP generation indispensable for muscle contraction. All single biochemical reactions, but one, need one or several enzymes to activate the conversion of a substrate into a product. The energy transformation in biochemical reactions is led by application of so-called free energy. Reversible and non-reversible reactions within a metabolic pathway are dependent on specific enzymes near or far from equilibrium. Allosteric enzymes are regulatory enzymes that provide the direction in the pathway. A regulatory enzyme is either activated or inhibited by small regulators (ligands). A reversible substrate cycle between A and B is catalyzed by two enzymes with different fluxes. The need of ATP production for muscle contraction is under the leadership of regulatory enzymes and available substrate stores. The improvement of adapted metabolic reactions under sport training depends on the appropriate increase of regulatory enzymes within the glycolytic and oxidative pathways. The amount of some specific enzymes is increased by training in order to improve the maximum activity of the metabolic pathway. Unfortunately, several publications do not precisely implicate the appropriate enzyme(s) to explain or reject the adaptation induced by the training schedule. A few examples will illustrate the factual interpretation and the inadequate allegation

    Insights into the reliability of Ni/Cu plated p-PERC silicon solar cells

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    Selective laser ablation of dielectric layers in combination with plated Ni/Cu/Ag contacts have been investigated by many photovoltaic researchers. Despite that there has been quite some practical progress on improved processing, the reliability of plated Ni/Cu/Ag cells still needs further insight and understanding. In this paper, the impact of laser induced defects that result from a ps-laser (wavelength 355nm) ablation on the performance of p-type PERC cells has been studied. A thermal stress experiment at 235 degrees C is applied. It is shown that the defects formed during the laser ablation process do indeed decrease the cell performance. A higher laser fluence results in lower fill factor and therefore lower efficiency. Moreover, the cells with higher laser fluence ablation degrade faster compared to the cells which had lower laser fluence to open the dielectric layer. The second part of the paper focuses on characterization of the p-n junction of the laser ablated cells by Deep Level Transient Spectroscopy (DLTS) before and after thermal ageing. A hole trap around 80K was found for all samples, which is related to point defects induced during the cell processing. A broad peak around 200K observed for the ablated cells with high laser fluence could correspond to dislocations induced by the laser ablation. This peak is shifted to higher energy (closer to the silicon mid-gap) after annealing, which may be due to impurity decoration during the annealing

    Correcting tensile test results of ECAE-deformed aluminium

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    Performing tensile tests on ECAE material reveals a long post-uniform elongation. In order to calculate correct true stress–true strain diagrams, three different approaches are used: measurements of the actual sample geometry, a neck evolution model proposed by Segal [V.M. Segal, S Ferrasse, F. Alford, Mater. Sci. Eng. A442 (2006) 321–326] and an inverse modelling method by finite element (FE) simulations

    Comparison between SiN x :H and hydrogen passivation of electromagnetically casted multicrystalline silicon material

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    International audienceThis work intends to compare two different passivation methods for electromagnetically continuous pulling silicon (EMCP): remote plasma hydrogenation and remote plasma enhanced CVD of SiN followed by high-temperature sintering. All experiments are carried out on textured and non-textured EMCP samples from the same ingot. To check the effect of high-temperature diffusion on EMCP, a n +-emitter is formed on one group of the samples using POCl 3 diffusion. Passivation capabilities of both techniques are checked using measurements of minority carrier lifetime by means of microwave photoconductance decay mapping. Solar cells are made to compare lifetime measurement with cell parameters.

    De-escalation of axillary irradiation for early breast cancer – Has the time come?

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    Introduction of sentinel lymph node biopsy, initially in clinically node-negative and subsequently in patients presenting with involved axilla and downstaged by primary systemic therapy, allowed for significant decrease in morbidity compared to axillary lymph node dissection. Concurrently, regional nodal irradiation was demonstrated to improve outcomes in most node-positive patients. Additionally, over the last decades, introduction of more effective systemic therapies has resulted in improvements not only at distant sites, but also in locoregional control, creating space for de-escalation of locoregional treatments. We discuss the data on de-escalation in axillary surgery and irradiation, both in patients undergoing upfront surgery and primary systemic therapy, with special emphasis on the feasibility of omission of nodal irradiation in patients undergoing primary systemic therapy. In view of the accumulating evidence, omission of axillary irradiation may be considered in clinically node-positive patients converting after primary systemic therapy to pathologically negative nodes on sentinel lymph node biopsy (preferably also with in-breast pCR), presenting with lower initial nodal stage, older age and were treated with breast-conserving surgery followed by whole breast irradiation. Omission of regional nodal irradiation in patients with aggressive tumor phenotypes achieving a pCR is under investigation. In patients undergoing preoperative endocrine therapy the adoption of axillary management strategies utilized in case of upfront surgery seems more suitable than those used in post chemotherapy-based primary systemic therapy setting.publishersversionpublishe
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