20 research outputs found

    Three-dimensional pore structure and ion conductivity of porous ceramic diaphragms

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    The ion conductivity of two series of porous ceramic diaphragms impregnated with caustic potash was investigated by electrochemical impedance spectroscopy. To understand the impact of the pore structure on ion conductivity, the three-dimensional (3-D) pore geometry of the diaphragms was characterized with synchrotron x-ray absorption tomography. Ion migration was calculated based on an extended pore structure model, which includes the electrolyte conductivity and geometric pore parameters, for example, tortuosity (τ) and constriction factor (β), but no fitting parameters. The calculated ion conductivities are in agreement with the data obtained from electrochemical measurements on the diaphragms. The geometric tortuosity was found to be nearly independent of porosity. Pore path constrictions diminish with increasing porosity. The lower constrictivity provides more pore space that can effectively be used for mass transport. Direct measurements from tomographs of tortuosity and constrictivity opens new possibilities to study pore structures and transport properties of porous materials

    IEA SHC Task 42/ECES Annex 29 – A Simple Tool for the Economic Evaluation of Thermal Energy Storages

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    Proceedings of the 4th International Conference on Solar Heating and Cooling for Buildings and Industry (SHC 2015)Within the framework of IEA SHC Task 42 / ECES Annex 29, a simple tool for the economic evaluation of thermal energy storages has been developed and tested on various existing storages. On that account, the storage capacity costs (costs per installed storage capacity) of thermal energy storages have been evaluated via a Top-down and a Bottom-up approach. The Top-down approach follows the assumption that the costs of energy supplied by the storage should not exceed the costs of energy from the market. The maximum acceptable storage capacity costs depend on the interest rate assigned to the capital costs, the intended payback period of the user class (e.g. industry or building), the reference energy costs, and the annual number of storage cycles. The Bottom-up approach focuses on the realised storage capacity costs of existing storages. The economic evaluation via Top-down and Bottom-up approach is a valuable tool to make a rough estimate of the economic viability of an energy storage for a specific application. An important finding is that the annual number of storage cycles has the largest influence on the cost effectiveness. At present and with respect to the investigated storages, seasonal heat storage is only economical via large sensible hot water storages. Contrary, if the annual number of storage cycles is sufficiently high, all thermal energy storage technologies can become competitive.This study is part of IEA SHC Task 42 / ECES Annex 29 „Compact Thermal Energy Storage - Material Development and System Integration“ (http://task42.iea-shc.org). The work of ZAE Bayern is part of the project PC-Cools_V and supported by the German Federal Ministry for Economic Affairs and Energy under the project code 03ESP138A. University of Zaragoza thanks the Spanish Government for the funding of their work under the projects ENE2008-06687-C02-02, ENE2011-28269-C03-01 and ENE2014-57262-R. University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). The research leading to these results has received funding from the European Union's Seventh Framework Program (FP7/2007-2013) under grant agreement n° PIRSES-GA-2013-610692 (INNOSTORAGE) and European Union’s Horizon 2020 research and innovationprogramme under grant agreement No 657466 (INPATH-TES). Laia Miró would like to thank the Spanish Government for her research fellowship (BES-2012-051861). The University of the Basque Country acknowledges the financial support of the Spanish’s Ministry of Economy and Competitiveness through the MicroTES (ENE2012- 38633) research project. The responsibility for the content of this publication is with the author

    [Effects of acoustic treatment of a dialysis room on the quality of life of patients]

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    International audienceThe impairment of quality of life experienced by patients treated with chronic hemodialysis results from many factors, including the care environment. Current regulations have significantly improved reception and treatment conditions for patients, but perhaps insufficient attention has been paid to the noise nuisance associated with dialysis equipment. We therefore found it useful to conduct a study on acoustic parameters in the dialysis room, and to evaluate the effects on perceived quality of life of an acoustic treatment intended to reduce the level of ambient noise. After measurements carried out under standard conditions, adapted noise absorption (devices panels and trellis) were installed in a treatment room of 8 posts hosting 32 volunteer patients, and their effects evaluated by a quality of life questionnaire administered 3 times (before, at the end of one week, and after the removal of the devices), each patient being his own witness. Measurements of ambient noise during dialysis periods and numerical modeling of the room were performed in parallel in order to search for correlations between the subjective changes expressed by the patients and the quantitative noise criteria. The results show that such devices can significantly reduce the perceived acoustic discomfort and their consequences (headaches), and suggest that these improvements are due to the frequential homogenization of the reverberation time in the room and the reduction of the low frequency components induced by the different sources of noise identified

    Intra-uterine growth restriction induced by maternal low-protein diet causes long-term alterations of thymic structure and function in adult male rat offspring.

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    Early malnutrition, the first environmental cause of intra-uterine growth restriction, impairs development of the thymus. Alterations of the thymic structure and function are reported at young ages in murine and ovine models. However, descriptions of thymic consequences of fetal malnutrition at adulthood are scarce. The present study investigates thymic structure, protein expression and cell selection process observed at postnatal day 180 (PND180) in male offspring of rats exposed to maternal low-protein diet (mLPD) compared with control diet during gestation. The thymic index was lower in adult offspring exposed to mLPD (P < 0·05). The thymic cortico-medullar ratio was lower in adult offspring exposed to mLPD (P < 0·05). At PND180, the protein expression of the lymphotoxin β receptor (P < 0·05), the autoimmune regulator (P < 0·05) and Forkhead Box P3 (FoxP3; P < 0·05) was all significantly lower in the mLPD group. The CD4+:CD8+ single-positive thymocyte subpopulation ratio and CD4+:CD8+ lymphocyte subpopulation ratio were increased in the mLPD group (P < 0·05). Among CD3+ lymphocytes, the proportions of CD4+CD8+ double-positive lymphocytes, CD31+ recent thymic emigrants and CD4+FoxP3+ lymphocytes were not significantly different between mLPD and control groups. These findings suggest mLPD during gestation induced long-lasting alterations in the development of thymic structure and thymic cell maturation and selection process in adult male rat offspring

    " Heritagisation " , a challenge for tourism promotion and regional development : an example of food heritage

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    Best paper elected 2013International audienceAs a marker of regional identity, heritage remains a complex field of inquiry. The discussion proposed here will use food to investigate the process of heritage construction or ‘heritigisation’ as an important issue for rural tourism promotion. If food is today considered to be a locus of inter-cultural exchange that contributes to the construction of social identities, then it could also be considered as an important resource for rural development strategy. As it is also strongly associated with the tourism sector, gastronomic heritage, in its forms of construction and mobilisation, calls into question the social and cultural dynamics of a given space. The objective of this discussion is two-fold and will treat the notion of heritage as a social construct and as a resource for action. We will attempt to answer the following question: At what point can heritage become a resource and component of professional opportunities? To what extent does this prove to be undeniably subject to the process of local ownership
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