1,078 research outputs found

    Theoretical study of thermally driven heat pumps based on double organic rankine cycle : Working fluid comparison and off-design simulation

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    Part of: Thermally driven heat pumps for heating and cooling. – Ed.: Annett Kühn – Berlin: Universitätsverlag der TU Berlin, 2013 ISBN 978-3-7983-2686-6 (print) ISBN 978-3-7983-2596-8 (online) urn:nbn:de:kobv:83-opus4-39458 [http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-39458]This study deals with a type of thermally driven heat pumps that consists of a reverse Rankine heat pump cycle, the compressor of which is driven by the turbine of a supercritical Organic Rankine Cycle (ORC). The application is residential heating (domestic hot water and floor heating) of small buildings requiring a cumulated thermal power of approximately 40 kW. An approach that enables the comparison of performance that can be expected with different working fluids is presented. It appears that R134a, R1234yf, R227ea and R236fa are among the best candidates. An off-design simulation tool of such thermally driven heat pumps has been implemented that includes both turbine and compressor off-design models. This thermally driven heat pump model has been used to predict the performance of an existing experimental prototype about to be tested

    Tackling Societal Challenges Related to Ageing and Transport Transition: An Introduction to Philosophical Principles of Causation Adapted to the Biopsychosocial Model

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    In geriatrics, driving cessation is addressed within the biopsychosocial model. This has broadened the scope of practitioners, not only in terms of assessing fitness to drive, but also by helping to maintain social engagements and provide support for transport transition. Causes can be addressed at different levels by adapting medication, improving physical health, modifying behaviour, adapting lifestyle, or bringing changes to the environment. This transdisciplinary approach requires an understanding of how different disciplines are linked to each other. This article reviews the philosophical principles of causality between fields and provides a framework for understanding causality within the biopsychosocial model. Understanding interlevel constraints should help practitioners overcome their differences, and favor transversal approaches to driving cessation

    Optimal process design for thermochemical biofuel production plants

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    Transport applications are a major global source of greenhouse gas emissions and the production of fuels that are renewable and neutral in CO2 is an important issue in chemical process research and development. Contrary to the biological routes that produce bioethanol and -diesel on industrial scale through fermentation or esterification, 2nd generation biofuels obtained through thermochemical processing of lignocellulosic and waste biomass by means of gasification and fuel reforming are expected to be truly sustainable since high conversion efficiencies and a decidedly positive environmental balance are achieved. The poster addresses the optimal design of such thermochemical fuel production processes with respect to its environomic (energetic, economic and environmental) performance. Thereby, the challenge is to develop design methodologies that allow the identification of the most promising conversion routes in a specific environmental and economical context. Thermo-economic process modelling and integration techniques are coupled with a multi-objective optimisation algorithm to target the best process technology and operating conditions for the trigeneration of fuels, heat and power. The approach is demonstrated on the production of synthetic natural gas from wood considering different gasification technologies and the possibility to increase the fuel yield from biomass and electrical power by integrating an electrolyser in the system

    Régime pauvre en hydrates de carbone et douleurs articulaires: quel rapport? [Low-carb diet and joint pain: how are they related?]

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    We report the case of a 69-year-old male who presented with acute bilateral ankle pain treated as acute gouty arthritis but resistant to colchicine and NSAIDs. In view of very high inflammatory parameters, septic arthritis was initially suspected but ruled out by joint aspiration; the final diagnosis was gouty arthritis. He finally responded well to a short course of oral prednisone. We found this case interesting in view of the initial differential diagnosis and association with a low-carb diet, known to be associated with many metabolic complications among which gout is frequent. [Authors]]]> Diet, Carbohydrate-Restricted ; Arthritis, Gouty fre oai:serval.unil.ch:BIB_F31B6FE6921F 2022-05-07T01:30:01Z openaire documents urnserval <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_F31B6FE6921F The 1925 Opium Purchasing Campaign in Laos: The Anatomy of a Colonial Scandal Rapin, A.-J. info:eu-repo/semantics/other misc 2014 <![CDATA[Opium purchasing campaigns, initiated in 1915, were abruptly interrupted ten years later following the discovery that the Douanes &amp; Régies of the General Government of Indochina had been victim of a gigantic fraud. Various inquiries expedited with a view to establishing responsibility for the fiasco, involving purchases made at Luang Prabang in 1925, highlight the dysfunctions affecting the colonial civil service. The 1925 scandal revealed not only the difficulties encountered by the French in their attempts to control the drug trade, but also the prevailing circumstantial inefficiency of the colonial bureaucracy

    Instruments for investigating fitness to drive - needs and expectations in primary care: a qualitative study

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    Background: Primary care physicians are often requested to assess their patients' fitness to drive. Little is however known on their needs to help them in this task. Aims: The aim of this study is to develop theories on needs, expectations, and barriers for clinical instruments helping physicians assess fitness to drive in primary care. Methods: This qualitative study used semi-structured interviews to investigate needs and expectations for instruments used to assess fitness to drive. From August 2011 to April 2013, we recorded opinions from five experts in traffic medicine, five primary care physicians, and five senior drivers. All interviews were integrally transcribed. Two independent researchers extracted, coded, and stratified categories relying on multi-grounded theory. All participants validated the final scheme. Results: Our theory suggests that for an instruments assessing fitness to drive to be implemented in primary care, it need to contribute to the decisional process. This requires at least five conditions: 1) it needs to reduce the range of uncertainty, 2) it needs to be adapted to local resources and possibilities, 3) it needs to be accepted by patients, 4) choices of tasks need to adaptable to clinical conditions, 5) and interpretation of results need to remain dependant of each patient's context. Discussion and conclusions: Most existing instruments assessing fitness to drive are not designed for primary care settings. Future instruments should also aim to support patient-centred dialogue, help anticipate driving cessation, and offer patients the opportunity to freely take their own decision on driving cessation as often as possible

    Cross-sectional study assessing the addition of contrast sensitivity to visual acuity when testing for fitness to drive.

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    The aim of this study is to quantify the importance of loss of contrast sensitivity (CS) and its relationship to loss of visual acuity (VA), driving restrictions and daytime, on-road driving evaluations in drivers aged 70+. A predictive cross-sectional study. Volunteer participants to a drivers' refresher course for adults aged 70+ delivered by the Swiss Automobile Club in western Switzerland from 2011 to 2013. 162 drivers, male and female, aged 70 years or older. We used a vision screener to estimate VA and the The Mars Letter Contrast Sensitivity Test to test CS. We asked drivers to report whether they found five driving restrictions useful for their condition; restrict driving to known roads, avoid driving on highways, avoid driving in the dark, avoid driving in dense traffic and avoid driving in fog. All participants also underwent a standardised on-road evaluation carried out by a driving instructor. Moderate to severe loss of CS for at least one eye was frequent (21.0% (95% CI 15.0% to 28.1%)) and often isolated from a loss of VA (11/162 cases had a VA ≥0.8 decimal and a CS of ≤1.5 log(CS); 6.8% (95% CI 3.4% to 11.8%)). Drivers were more likely (R &lt;sup&gt;2&lt;/sup&gt; =0.116, P=0.004) to report a belief that self-imposed driving restrictions would be useful if they had reduced CS in at least one eye. Daytime evaluation of driving performance seems limited in its ability to correctly identify difficulties related to CS loss (VA: R &lt;sup&gt;2&lt;/sup&gt; =0.004, P=0.454; CS: R &lt;sup&gt;2&lt;/sup&gt; =0.006, P=0.332). CS loss is common for older drivers. Screening CS and referring for cataract surgery even in the absence of VA loss could help maintain mobility. Reduced CS and moderate reduction of VA were both poor predictors of daytime on-road driving performances in this research study
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