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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.
11

Analyzing The Design Of Submersible Lifted Deviated Oil Wells

Kahya, Ali Cenk 01 January 2005 (has links) (PDF)
Electrical Submersible Pumping (ESP) is a well known artificial lift technique in reservoirs having high-water cut and low gas-oil ratio. It is known as an effective and economical method of producing large volumes of fluid under different well conditions. ESP equipments are capable of producing in a range of 200 b/d to 60.000 b/d. A case study was done, by designing 10 deviated or horizontal wells selected from the Y-oilfield in Western Siberia. SubPUMP software developed by IHS Energy is used for designing the ESP systems of these wells. These 10 wells will be working with variable speed drives. After selecting the available equipment from the inventory, the best running frequencies are selected for these wells. Evaluations of the designs are made from the pump performance graphs of each well. The pumps should work within their optimum efficiency ranges. These ranges can be seen from the pump performance curves. If the designs made are not within these efficiency ranges, designs should be evaluated and selecting new equipment should be should be an option. Because working outside the optimum efficiency ranges will decrease the production, shorten the runlifes of the pumps and the production will not be stable.
12

Dynamics of the voltage-sensor domain in voltage-gated ion channels : Studies on helical content and hydrophobic barriers within voltage-sensor domains

Schwaiger, Christine S. January 2011 (has links)
Voltage-gated ion channels play fundamental roles in neural excitability and thus dysfunctional channels can cause disease. Understanding how the voltage-sensor of these channels activate and inactivate could potentially be useful in future drug design of compounds targeting neuronal excitability. The opening and closing of the pore in voltage-gated ion channels is caused by the arginine-rich S4 helix of the voltage sensor domain (VSD) moving in response to an external potential. Exactly how this movement is accomplished is not yet fully known and an area of hot debate. In this thesis I study how the opening and closing in voltage-gated potassium (Kv) channels occurs. Recently, both experimental and computational results have pointed to the possibility of a secondary structure transition from α- to 3(10)-helix in S4 being an important part of the gating. First, I show that the 3(10)-helix structure in the S4 helix of a Kv1.2-2.1 chimera protein is significantly more favorable compared to the α-helix in terms of a lower free energy barrier during the gating motion. Additional I suggest a new gating model for S4, moving as sliding 310-helix. Interestingly, the single most conserved residue in voltage- gated ion channels is a phenylalanine located in the hydrophobic core and directly facing S4 causing a barrier for the gating charges. In a second study, I address the problem of the energy barrier and show that mutations of the phenylalanine directly alter the free energy barrier of the open to closed transition for S4. Mutations can either facilitate the relaxation of the voltage-sensor or increase the free energy barrier, depending on the size of the mutant. These results are confirmed by new experimental data that supports that a rigid, cyclic ring at the phenylalanine position is the determining rate-limiting factor for the voltage sensor gating process. / QC 20110616
13

Vzdálené školící pracoviště / Remote training station

Kučera, Tomáš January 2019 (has links)
The purpose of the thesis is design and contruction of remote training station for training with Schneider Electric products. Its purpose is to introduce company PLCs, familirize user with configuring variable speed drives and servo drives and prezenting Machine Advisor and EcoStruxure Augmented Operator Advisor online servives The begining is dedicated to introduction to company and a range of its products in the field of industrial automation. In second chapter, I select components for building training station. Third chapter is dedicated to assembly of station. In fourth chaper I describe programing of individual elements and example.
14

Contribution to the Synchronous Reluctance Machine Performance Improvement by Design Optimization and Current Harmonics Injection / Contribution à l'amélioration des performances d'une machine synchrone à réluctance variable synchrone par optimisation de la conception et injection d'harmoniques de courant

Yammine, Samer 06 November 2015 (has links)
Cette thèse est consacré à l’évaluation et l’amélioration de la performance de la machine synchrone à réluctance variable pour des applications à vitesse variable en général et pour les applications automobiles en particulier. Les deux axes de développement sont la conception de la machine et l’injection des harmoniques de courants de phase. Le rotor est un élément important dans la conception de la machine, et un intérêt particulier est dédié à la conception et l’évaluation du rotor pour améliorer la performance de la machine. Une méthode analytique est proposée dans la thèse pour concevoir le rotor. Plusieurs éléments tels que les ponts qui maintiennent le rotor mécaniquement résistant, ainsi que le rapport d’isolation d’axe q (rapport air-acier) sont étudiés. Une étude de conception assistée par ordinateur basé sur un problème d’optimisation paramétrique est présentée aussi. Les trois familles des algorithmes d’optimisation sont évaluées pour la procédure d’optimisation: un algorithme à base de gradient (algorithme de Newton Quasi), un algorithme non-évolutionnaire sur la base de non-gradient (Nelder Mead Simplex) et un algorithme évolutif sur la base non-gradient (algorithme génétique). Les designs de machines basées sur la procédure analytique et la procédure d’optimisation sont testés sur un banc d’essai. Le deuxième axe d’études de la thèse est l’injection d’harmoniques dans les courants de phase de la machine à réluctance variable synchrone. L’interaction des harmoniques de courant avec les harmoniques spatiales des inductances est étudiée et formalisée pour une machine à m-phases. Ensuite, le concept d’injection d’harmoniques est évalué dans le cas particulier d’une machine à deux phases. Cette étude montre l’avantage de l’injection d’harmoniques dans la réduction de l’ondulation de couple de la machine. Un design d’une machine est finalement développé pour une application automobile sur la base de l’optimisation paramétrique du stator et du rotor. Cette conception est évaluée pour les spécifications imposées électromagnétiques par une application de traction à puissance moyenne / This thesis is dedicated to the evaluation and the improvement of the synchronous reluctance machine’s performance for variable speed drive applications in general and for automotive applications in particular. The two axes of development are machine design and phase current harmonics injection. The rotor is an important element in the machine design and particular emphasis is placed to the design and evaluation of the rotor for enhancing the machine performance. An analytical procedure is proposed for the rotor design. The rotor elements like the ribs and the bridges that maintain the rotor mechanically strong as well as the q-axis insulation ratio (air-to-steel ratio) are studied. A computer-aided design study based on a parametric optimization problem is presented as well. The main three families of the optimization algorithms are evaluated for the optimization procedure: a gradient-based algorithm (Quasi Newton Algorithm), a non-gradient based non-evolutionary algorithm (Nelder Mead Simplex) and a non-gradient based evolutionary algorithm (Genetic Algorithm). The machine designs based on the analytical procedure and the optimization procedure are both manufactured and tested on a bench. The second axis of study of the thesis is the injection of harmonics in the phase currents of the synchronous reluctance machine. The interaction of current harmonics with the spatial inductance harmonics is studied and formalized for an m-phase machine. Then, the harmonics injection concept is evaluated in the particular case of a 2-phase machine. This study shows the benefi t of harmonics injection in the reduction of the machine torque ripple. A synchronous reluctance machine design is fi nally developed for an automotive application based on parametric optimization of the stator and rotor. This design is evaluated for the electromagnetic specifi cations imposed by a mid-power electric vehicle traction application
15

Transposition des gros vaisseaux avec septum intact ou communication interventriculaire : échocardiographie fœtale et analyse NIRS périopératoire

Charbonneau, Laurence 08 1900 (has links)
Ce mémoire par article est une étude des différences hémodynamiques entre la dextro-transposition des gros vaisseaux (TGV) avec communication interventriculaire (CIV) et la TGV avec septum intact (SI) pendant la période fœtale et périopératoire. Il est à noter que SI fait référence au septum inter ventriculaire et non au septum inter auriculaire. La présence d’une communication inter auriculaire étant, comme nous le verrons dans ce travail, un élément important de la physiologie des fœtus/nouveau-nés porteur de TGV. Le document est divisé en deux parties importantes. La première partie est composée du chapitre 1 qui présente une revue de littérature détaillant les notions importantes à la compréhension de la problématique et du chapitre 2 qui décrit la méthodologie utilisée pour répondre à la question de recherche. On détaille d’abord les méthodes d’acquisition des échocardiographies fœtales ainsi que les principales mesures effectuées à partir de celles-ci. Ensuite, on y décrit les technologies de la spectroscopie proche infrarouge avancée et de la spectroscopie à corrélation diffuse (NIRS-DCS) permettant de recueillir les données hémodynamiques sur la microvascularisation cérébrale des nouveau-nés. La seconde partie est constituée du chapitre 3 qui est le manuscrit accepté au journal Ultrasound in Obstetric & Gynecology pour publication. Celui-ci décrit les différences hémodynamiques entre les patients ayant une TGV&CIV et les TGV&SI et présente les différences retrouvées en échocardiographie fœtale et en hémodynamie cérébrale périopératoire étudiée à l’aide de la NIRS avancée. Ensuite, nous présentons dans le chapitre 4 une discussion sur les principaux impacts cliniques et sur d’éventuelles améliorations. / This master’sthesis is composed of an article and a study. They present hemodynamic differences between patients with transposition of the great arteries (TGA) and ventricular septum defect (VSD), and TGA with intact ventricular septum (IVS) during fetal and perioperative periods. This document is divided into two principal sections. The first section includes Chapter 1 that presents a review of literature detailing important notions to understand the problematic, and Chapter 2, that describes the methodology used to answer our research question. First, we detailed acquisition data and measured parameters of the fetal echocardiography exams. Then, we describe advanced near infrared spectroscopy (NIRS-DCS) technology that allowed hemodynamic data acquisition on the cerebral microvascularization of neonates. The second section is composed of Chapter 3, the manuscript accepted in Ultrasound in Obstetric & Gynecology journal for publication. The aim of this article is to describe hemodynamic differences between patients with TGA&VSD and TGA&IVS. It describes fetal echocardiography and cerebral perioperative hemodynamic differences studied with advanced NIRS. Next, we present in Chapter 4 a more detailed discussion with principal impacts on the clinical field and future improvements.

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