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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

Sistema supervisório de parâmetros de máquinas elétricas via TCP/IP e painel eletrônico de mensagens / Supervisory system of electric machine\'s parameter via TCP/IP and message displays

Fernando Ranieri 17 August 2007 (has links)
Com o advento da internet, a comunicação entre sistemas remotos foi amplamente facilitada, tornando viável a aplicação de sistemas supervisórios através dela, principalmente via protocolo TCP/IP. Embora esses sistemas já sejam empregados na indústria, principalmente utilizando como driver os controladores lógicos programáveis (CLP\'s), a implementação de qualquer sistema mais simples de supervisionamento teria um custo elevado, devido tanto ao preço do hardware quanto do software envolvido. Além disso, os programas supervisórios existentes fornecem um número limitado de recursos de visualização, que se restringem principalmente ao software. Assim, o que se propõe nesse trabalho é um sistema supervisório de baixo custo, via TCP/IP, aplicado em máquinas elétricas, mas que pode ser generalizado na supervisão de outros tipos de sistemas, onde o monitoramento remoto é necessário. Além da exibição convencional dos parâmetros supervisionados através de gráficos e labels, o sistema permite também que esses sejam exibidos através de painéis eletrônicos, fornecendo assim, uma nova interface visual ao usuário com o intuito de facilitar sua supervisão. / The advent of internet simplified the comunication between remote systems, allowing the application of supervisory systems through the internet, mainly using the TCP/IP protocol. Although these systems have already been employed in industry, using the Programmer Logic Controller (PLC\'s) as driver, the implementation of any simple supervisory system could have an expensive cost, due to the prices of hardware and software employed. Moreover, the existing supervisory systems provide limited visual resources, restricted to the used software. So, this work presents a low cost supervisory system, via TCP/IP, applied to electric machines but it can be generalized in the supervision of differents types of systems, where the remote monitoring is necessary. Besides the conventional displaying of the monitored parameters through graphics and labels, the developed system allows the exhibition of the supervisioned parameters using eletronic panels, providing an alternative visual interface to the user so that their supervision becomes easier.
22

Modelling and elucidation of photoreaction kinetics : applications and actinometry using nifedipine, nisoldipine, montelukast, fluvoxamine and riboflavin

Maafi, Wassila January 2016 (has links)
The kinetics of drugs photodegradation have traditionally been treated using thermal kinetic analysis methods consisting most commonly in zero and first order kinetics. These treatment strategies were shown to lack specificity and present a number of limitations when applied to photoreactions kinetics. Nevertheless, these methods have widely been used due to a lack of integrated rate-laws for the majority of photoreactions types, in turn, due to the presence of a variable time-dependent factor in most photoreactions rate-laws that prevents their mathematical integration. To address these limitations, a new methodology for the development and validation of semi-empirical integrated rate-laws that faithfully describe photoreactions kinetics and photoreactions simulated cases generated by numerical integration methods (NIMs), is hereby presented. Using this methodology, a new kinetic order was ascribed to photoreactions namely the Φ-order kinetics. Semi-empirical integrated rate-laws were, thus, developed for three photoreaction types namely, unimolecular, AB(1Φ), photoreversible ,AB(2Φ), and consecutive, AB4(4Φ), photoreactions. The proposed models were further tested experimentally on drugs following these photodegradation mechanisms using; nifedipine and nisoldipine for unimolecular photoreactions; montelukast and fluvoxamine for photoreversible reactions; and riboflavin for consecutive photoreactions. The developed models not only accurately described the photoreaction kinetics of these drugs but also allowed the determination of all the kinetic parameters that characterise them. Furthermore, the above studied drugs were shown to act as precise and simple actinometers when analytically treated with the Φ-order kinetic methods, hereby presented. A universal standard method for the precise and worldwide reproducible study of drugs stability and compounds photoreactions, based on monochromatic irradiation and Φ-kinetics data analysis, is also detailed and adopted throughout the thesis. Finally, two new kinetic parameters namely, the pseudo-rate-constant and pseudo-initial velocity have been identified and shown to be more reliable and accurate in the description and universal comparison of photoreactions kinetics.
23

Mesure de la température à l'échelle microscopique par voie optique dans la gamme ultraviolet-visible / Microscale temperature measurements by optical way in the ultraviolet-visible range

Pierre, Thomas 10 December 2007 (has links)
Cette étude porte sur la mesure de la température à l’échelle microscopique par voie optique dans la gamme UV-visible par comptage de photons à l’aide d’un PMT refroidi. À partir des avantages et des inconvénients de chaque technique existante, la première partie permet de comprendre les orientations de nos travaux. Le Second Chapitre montre et insiste sur l’intérêt de travailler aux courtes longueurs d’onde (limite de diffraction, précision sur la mesure...), d’utiliser la méthode multi-spectrale pour s’affranchir de paramètres inconnus (e.g. l’émissivité) en choisissant judicieusement les longueurs d’onde de travail, ainsi que les lois statistiques classiques pour mesurer le flux photonique sachant son émission aléatoire. Le Chapitre Trois présente le banc de mesure (microscope optique, système de mesure du flux photonique...) et une attention toute particulière est portée sur la conception des éléments chauffants servant à l’étalonnage. Le Quatrième Chapitre présente les résultats en températures obtenues à l’aide des lois statistiques. Ils valident le bon fonctionnement du dispositif, la mise au point de la zone microscopique, et l’intérêt de bien modéliser les filtres monochromatiques. Enfin, des améliorations sur la précision de la mesure (réseau de diffraction, analyseur multi-canal) et pour mesurer des températures plus faibles (LIF, méthode corrélation temporelle) sont présentées dans le Cinquième Chapitre / The aim of this study is to measure microscale temperature by optical way in the UV-visible range by photons counting using a cooled PMT. From the existing techniques advantages and disadvantages, this first part allows to understand the choices of this study. The second part shows and underlines the interest in working in short wavelengths (diffraction limit, measurement accuracy), in using the multi-spectral method to get rid of unknown parameters (e.g. emissivity) by choosing judicious working wavelengths, as well as the statistic laws to measure the photonic flux knowing its random emission. The third chapter presents the optical bench (optical microscope, photonic flux measurement facility…). A particularly attention is given to the design of the heated elements, which allow to calibrate the facility. The fourth part exposes the temperature results obtained through statistic laws. They validate the well-running of the facility, the microscopic area focusing, and the interest to model correctly the filters. Finally, measurement accuracy improvements (diffraction grating, multi-channel analyzer) and lower temperature measurement techniques (LIF, time-correlated method) are presented in the fifth part
24

Systém pro zobrazování černobílých snímků v nepravých barvách (Pseudocolor) / System for Imaging of the Monochromatic Pictures in the Pseudo Color

Kaděrka, Petr January 2008 (has links)
This diploma thesis treats the possibilities of the black-white picture depiction in pseudo colors (Pseudocolor). The individual methods, software or hardware are described there and the detailed block scheme of the system Pseudocolor is suggested. The block scheme is created on the basis of gained theoretical knowledge. In the thesis, individual functional blocks of the scheme are described and their circuit designs are realized. Some of the functional blocks are simulated by the PSpice program and accompanied by corresponding signal process data. The suitable choice of the active and passive components is performed, from which the general integration of the system Pseudocolor is made. All the source materials for the realization of the device are given there – double-sided drawing of the printed circuit, layout and specification of the components.

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