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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Problèmes respiratoires et exposition aux émissions d’industries au Saguenay

Labelle, Rémi 11 1900 (has links)
La majorité des études qui ont examiné les effets respiratoires d’une exposition de courte durée à la pollution de l’air ont été réalisées en milieu urbain. En milieu pollué par des sources industrielles, la nature de l’exposition diffère de celle en milieu urbain. Le premier objectif de ce mémoire visait une recension des études traitant de l’association entre les effets respiratoires chez l’enfant et l’exposition aux émissions de polluants industriels. La majorité des études suggèrent que l’exposition aux émissions de polluants émis par des industries est associée à un accroissement des problèmes respiratoires. Dans ces études, l’effet de l’exposition de courte durée a rarement été étudié. L’autre objectif du mémoire était d’évaluer l’association entre une exposition journalière aux émissions de pollution atmosphérique d’un complexe industriel (deux fonderies et une usine de raffinage de l’alumine) du Saguenay, Québec, et les hospitalisations pour problèmes respiratoires des enfants de 0 à 4 ans vivant près de celles-ci (<7.5 km), à l’aide d’une étude épidémiologique de type cas-croisé. Le pourcentage d’heures où le domicile de l’enfant était sous les vents provenant de la direction du complexe industriel et les maxima et moyennes journalières des concentrations de dioxyde de soufre (SO2) et de particules fines (PM2.5) ont été recueillis du 1er janvier 2001 au 31 décembre 2010 afin d’estimer l’exposition. Des régressions logistiques conditionnelles ont été employées pour estimer les rapports de cotes (OR) et les intervalles de confiance à 95%. Les hospitalisations pour asthme et bronchiolite chez les jeunes enfants étaient associées à l’augmentation de l’exposition journalière aux émissions, estimée par le pourcentage d’heures sous les vents. Les résultats de ce mémoire suggèrent que l’exposition aux émissions industrielles de polluants de l’air est associée à des effets respiratoires chez les enfants. / Most studies performed to date that assessed the respiratory effects of short term exposure to air pollutants have been performed in urban environments. Air pollutant mixtures in urban environments may differ than those originating from industrial settings. The first objective of this thesis was a literature revue of all studies published to date on the respiratory effects of exposure to industrial emissions in children. Studies published to date usually report, that exposure to industrial emissions of air pollutants are associated with respiratory effects. In these studies, effects of short-term exposure have rarely been studied. The second objective of this thesis was to estimate the association between daily exposure to emissions of atmospheric pollution coming from an industrial complex (with two smelters and an alumina refining plant) in Saguenay, Quebec, and hospitalizations for respiratory problems in children aged 0 to 4 years living near nearby (<7.5 km) with an epidemiologic case-crossover design. The percentage of hours when the residence of the children was downwind from the industrial complex and the daily average and peak concentrations of sulfur dioxide (SO2) and particulate matter (PM2.5), measured from January 1st 2001 to December 31th 2010, were used to estimate the exposure of children. Conditional logistic regressions were used to estimate the associations with odds ratios (OR) and the 95% confidence intervals. Hospitalizations for asthma and bronchiolitis in young children living near the aluminum/industrial complex increased with the daily exposure, estimated by the percentage of hours downwind. Results from this thesis suggest that exposure to industrial emissions of air pollutants is associated with respiratory effects in children.
22

Företag i perifera regioner : fallstudier av företagartradition, företagsmiljö och företags framväxt i Norrbottens inland / Industries in peripheral regions : case studies of industrial tradition, industrial environment and growing firms in the interior of Norrbotten

Sundin, Elisabeth January 1980 (has links)
This is a study of how industries develop in regions that are industrially weak, exemplified by Norrbotten, the northernmost province of Sweden. Developing industries are represented by three companies manufacturing prefabricated wooden houses, situated in the municipalities Övertorneå, Kalix (Morjärv) and Älvsbyn in the interior of Norrbotten.For the period ending in 1918, the economy of Norrbotten is analysed in terms of staple theory. Thereafter, an analysis in dependency theoretic terms is judged to be more relevant. The communities in which the house factories are located are described similarly.Övertorneåand Mor j ärv are in the periphery of a peripheral region. There has never been any locally generated economic life of any importance. The house factory in the community first mentioned was established there in 1970 by AMS (The Swedish Labour Market Board). The other one was started by a local entrepreneur in the 1930's. It has changed hands several times, being incorporated into ever larger conglomerates. The third company studied was started by a local carpenter who still controls it. The factory is located in Älvsbyn, near Piteå, which has to be considered the center of the periphery.The integration of these three companies with other local firms, and their economic importance was studied in terms of their buying behavior. The method of investigation was a study of the internal records of the firms.All three of the companies showed that a decrease in the local and regional shares of their total purchases took place between the sample years studied. A comparison of the companies showed the Älvsby factory, the one locally initiated and controlled, to have by far more solid local and regional foundations than the other two. This could partly be explained by firm-related theories but the most important factor seemed to be the industrial tradition in the communities. Industrial tradition is a factor mostly determined by the position of a community in a dependency hierarchy, in part however, it is controllable by local decision-makers and individual entrepreneurs.Even for the company with the best local foundations, there was a drop in local and regional shares of purchases. The reason for this is the size of the company in relation to other local industries. The company has reached the limits of the capacity of the local community to support it. Such limits exist everywhere but their exact level depends on the status of the community and region they are in, the line of industry, the nature of ownership, etc.A series of implications for regional politics can be derived from the present study. Economic measures designed to improve weak industrial areas should be undertaken with utmost care in order not to damage existing local economy. Much greater efforts should be made to study the conditions of existing economic life and its potential for change, i.e. to study the historical development. / digitalisering@umu
23

Avaliação do desempenho de uma Rede 802.11g em uma Usina Termoelétrica. / Evaluation of the performance of an 802.11g Network in a Thermoelectric Plant.

VALADARES, Dalton Cézane Gomes. 01 May 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-01T13:36:45Z No. of bitstreams: 1 DALTON CÉZANE GOMES VALADARES - DISSERTAÇÃO PPGCC 2015..pdf: 6500440 bytes, checksum: f8b244a64bf81646d322b68023c204d9 (MD5) / Made available in DSpace on 2018-05-01T13:36:45Z (GMT). No. of bitstreams: 1 DALTON CÉZANE GOMES VALADARES - DISSERTAÇÃO PPGCC 2015..pdf: 6500440 bytes, checksum: f8b244a64bf81646d322b68023c204d9 (MD5) Previous issue date: 2015-07 / No âmbito industrial, é sabido que as redes sem fio são as mais indicadas, já que possuem baixo custo de implantação, maior flexibilidade e são menos invasivas ao ambiente. Na literatura, dentre as tecnologias de rede sem fio aplicadas em ambientes industriais, pouco destaque é dado às tradicionais 802.11a/b/g, conhecidas pelo uso doméstico e chamadas WiFi (acrônimo de Wireless Fidelity). A pesquisa, ora descrita, tem como objetivo avaliar o desempenho de uma rede 802.11g em um ambiente industrial de uma usina termoelétrica (UTE). O cenário de análise foi constituído de 4 enlaces de comunicação, com o principal deles possuindo uma distância de, aproximadamente, 150 metros. Para a avaliação do desempenho da rede, foram consideradas três métricas: taxa de perda de pacotes, Taxa de Transferência e tempo de resposta. Os testes foram realizados por meio do estabelecimento de comunicação entre pontos dentro da sala de motores (primeiro enlace) e o servidor localizado na sala de administração (último enlace). Os resultados obtidos para potência do sinal foram comparados aos valores estimados por meio do modelo Log Distance Path Loss. Observou-se que o desempenho da comunicação realizada pela rede não sofreu degradação significativa, mesmo em um ambiente sujeito à interferência eletromagnética e demais características intrínsecas a uma UTE. Após a análise concluída, verificou-se a viabilidade do uso da tecnologia 802.11g para comunicação de dados em ambientes com características similares às de uma usina termoelétrica. / In industry, it is known that wireless networks are the most suitable, since they have low implementation cost, greater flexibility and are less invasive to the environment. In the literature, among the wireless network technologies applied in industrial environments, little attention is given to traditional 802.11a/b/g, known by the domestic use and by the acronym WiFi (Wireless Fidelity). This work aims to evaluate the performance of an 802.11g network in an industrial environment of a thermal power plant. The scenario consists of four communication links, with the main one having a distance of approximately 150m. For the evaluation of network performance, we considered three metrics: packet loss rate, bandwidth and response time. Tests were carried out through the establishment of communication between points within the engine square (first link) and the server located in the boardroom (last link). The obtained results for the signal strength at each point were compared with the estimated values by the Log Distance Path Loss Model. It was verified that the performance of the communication performed by the network did not suffer significant degradation, even being in an environment subject to considerable electromagnetic interference. After the concluded analysis, it was found feasibility of using 802.11g technology for data communication in environments with characteristics similar to those of a thermal power plant.
24

Modélisation hybride du canal de propagation dans un contexte industriel / A hybrid radio channel model for industrial environment

Hariri Essamlali, Kaoutar El 19 December 2014 (has links)
Ce travail de thèse concerne la modélisation du canal de propagation dans les milieux industriels. Dans ce contexte, le canal de propagation a un comportement différent de celui classiquement rencontré en indoor. Cela est dû à l'aménagement des bâtiments qui sont plus grand et ouverts ainsi qu'à la présence de machines, d'objets mobiles et d'autres matériaux métalliques rencontrés dans ces environnements. Ainsi, les modèles de canaux indoor existants ne sont plus valides. L'utilisation de modèles déterministes comme alternative est possible mais limitée en raison du temps de calcul qui en découle.Pour répondre à cette problématique, nous proposons un modèle hybride de canal s'inspirant d'une méthode à tracer de rayons 3D et du modèle WINNER. L'originalité de ce modèle repose sur son caractère hybride consistant, en prétraitement, à partitionner l'environnement en zones de visibilité ou de non-visibilité «faible» et «forte» sur des critères déterministes liés à la propagation des ondes. Un modèle statistique, type WINNER, reprenant le concept de cluster est ensuite "joué" au sein de chacune des ces zones reproduisant ainsi fidèlement l'évolution des paramètres caractéristiques des clusters identifiés. Nous avons validé notre modèle en le comparant d'abord à un modèle déterministe et ensuite à la mesure. Sa robustesse ainsi que celle de WINNER sont testées en les simulant dans trois environnements différents et en les comparant au modèle déterministe à tracer de rayons. / This thesis focuses on the modeling of the propagation channel in industrial environments. In this context, the propagation channel has a different behavior than typically encountered in indoor. This is due to the construction of buildings that are larger and open and the presence of machines, moving objects and metal materials encountered in these environments. Thus, the existing indoor channel models are not valid. Using deterministic models as an alternative is possible, but limited by the computing time.To address this problem, we propose a hybrid channel model for communications in industrial environments inspired by a ray tracing method and Winner model. The originality of this model is its hybrid nature consisting, in preprocessing, in partitionning the environment in areas of visibility or non-visibility «weak» and «strong» based on deterministic criteria related to the wave propagation. A statistical model, as WINNER , using the concept of cluster is then played in each of these areas and faithfully reproducing the evolution of the characteristic parameters of the identified clusters. We have validated our model by comparing it firstly to a deterministic model and then to measurement. Its robustness as well that of WINNER are tested by simulating them in three different environments and by comparing them with the deterministic model.

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