1,721,115 research outputs found
Development of Advanced Analysis Methods for Experimental Data on Fouling Phenomena in Heat Exchangers in real operating condition
No full textL’absence d’outils dédiés, permettant aux industriels d’agir efficacement sur les phénomènes d’encrassement des échangeurs thermiques est à l’origine de cette étude. L’objet de la thèse est de construire une méthodologie pour permettre d’évaluer in situ les paramètres caractéristiques de l’effet d’encrassement, de mettre en œuvre et de valider ensuite des méthodes d’analyse de ces données pour en extraire un outil de prédiction des effets d’encrassement à partir de la connaissance d’un nombre réduit de données de fonctionnement. Cette démarche réalisée pour différents systèmes thermohydrauliques identifiés et instrumentés privilégie des processus d’encrassement dans des récupérateurs thermiques sur fumées et gaz de combustion ainsi que sur des eaux chargées. Nous concentrerons nos efforts sur les phénomènes d’encrassement d’échangeurs en environnement réel, en insistant sur le développement des méthodologies d’identification des cinétiques d’encrassement et sur les démarches de validation pour des cas concrets. Enfin, une application de programme de maintenance, par différentes stratégies de nettoyage limitant les dégradations de l’efficacité des installations étudiées, sera conduite : elle permettra d’identifier les stratégies les plus adaptées. La finalité de la démarche étant destinée à terme, pour une installation quelconque, de développer un outil expert à partir d’un nombre réduit d’informations. Celui-ci permettrait d’évaluer la cinétique d’encrassement de l’équipement thermique pour une période future et d’élaborer une pratique de maintenance dans la perspective d’une réduction des coûts énergétiques et des coûts d’intervention.The lack of dedicated tools, enabling at industrials to act effectively on the fouling phenomena in heat exchanger is the origin of this study. The purpose of the thesis is to develop a methodology in order to assess - in situ -at the characteristic parameters of the fouling effects, implement and then validate the data analysis methods to extract a fouling effects prediction tools from the knowledge of a limited number of operating data. This approach realized for different identified and instrumented thermohydraulic systems favors the fouling process in heat exchangers on charged water. We will focus on the phenomena of fouling of heat exchangers in a real environment, with emphasis on the development of methodologies to identify the fouling kinetic's and on the approach for validation of practical and concrete cases. Finally, application of a maintenance program by different cleaning strategies limiting the degradation of the efficiency of the facilities studied will be conducted: it will identify the most appropriate strategies. The purpose of the initiative, intended to run for any installation, is to develop an expert tool from reduced amount of information. This tool assesses to evaluate the kinetics of fouling of the thermal equipment for a future period and develop a maintenance practice from the perspective of reducing energy costs and costs of intervention
Use of Phase Change Materials in buildings : comprehensive reviews, experiments, parametric study and physical analyzes
No full textLes bâtiments sont considérés comme des facteurs clés qui affectent la demande énergétique mondiale et ont des effets importants sur les émissions de gaz à effet de serre résultant des dispositifs de chauffage et de refroidissement intégrés. La transformation des rénovations et la création de nouveaux compartiments commerciaux et résidentiels visent à répondre aux exigences des constructions vertes durables et des bâtiments à énergie nette zéro développés pour soutenir le confort thermique et le bien-être humain. Une méthode consiste à intégrer le stockage d'énergie thermique à chaleur latente, en particulier les matériaux à changement de phase (MCP) dans les bâtiments: de manière active et passive. Le projet actuel présente une revue bien approfondie sur l’utilisation du MCP dans les bâtiments pour le chauffage, refroidissement et les applications hybride. Il a été démontré que les combinaisons et l'hybridation possibles de différentes applications MCP peuvent améliorer l'efficacité énergétique des bâtiments. Deux nouveaux prototypes modulaires avancés identiques, équipés de conteneurs de macro-encapsulation PCM à conductivité thermique améliorée, ont été proposés et mis en œuvre. L'étude se concentre sur des recherches expérimentales pour des systèmes de chauffage par le sol hydroniques/électriques actifs intégrés à des plaques PCM d'huile de coco (CO) impliquant des analyses paramétriques, thermiques et économiques. A partir les résultats obtenues expérimentalement, il a été constaté que l’utilisation correcte du PCM peut conduire à des économies, des conforts thermiques souhaités, et une efficacité énergétique élevée.Buildings are considered key factors that affects global energy demand and have significant effect on greenhouse gas emissions resulting from integrated heating and cooling devices. Transforming renovations and establishing new commercial and residential compartments are directed to meet the requirements of sustainable green constructions and further developed Net Zero Energy Buildings sustaining thermal comfort and human welfare. To fulfill this goal, one method is integrating latent heat thermal energy storage particularly Phase Change Materials (PCM) in buildings: actively and passively. The current research project recent work on the use of PCM in buildings for heating, cooling and hybrid applications. It was shown that possible combinations and hybridization of different PCM applications can enhance building energy efficiency. Two identical new advanced modular prototypes, equipped with enhanced thermal conductivity PCM macro-encapsulation containers, were proposed and implemented. The study focuses on experimental investigations for active hydronic/electrical radiant floor heating systems integrated with coconut oil (CO) PCM plates involving parametric, thermal and economic analyses. According to the experimental results, it was found that proper utilization of CO-PCM plates coupled to a controlled active system leads great economy, to high comfortable conditions and high energetic efficiency
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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