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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

Over-current relay model implementation for real time simulation & Hardware-in-the-Loop (HIL) validation

Almas, Muhammad Shoaib, Leelaruji, Rujiroj, Vanfretti, Luigi January 2012 (has links)
Digital microprocessor based relays are currently being utilized for safe, reliable and efficient operation of power systems. The overcurrent protection relay is the most extensively used component to safeguard power systems from the detrimental effects of faults. Wrong settings in overcurrent relay parameters can lead to false tripping or even bypassing fault conditions which can lead to a catastrophe. Therefore it is important to validate the settings of power protection equipment and to confirm its performance when subject to different fault conditions. This paper presents the modeling of an overcurrent relay in SimPowerSystems (\textsc {matlab}/Simulink). The overcurrent relay has the features of instantaneous, time definite and inverse  definite minimum time (IDMT) characteristics. A power system is modeled in SimPowerSystems and this overcurrent relay model is incorporated in the test case. The overall model is then simulated in real-time using Opal-RT's eMEGAsim real-time simulator to analyze the relay's performance when subjected to faults and with different characteristic settings in the relay model. Finally Hardware-in-the-Loop validation of the model is done by using the overcurrent protection feature in Schweitzer Engineering Laboratories Relay SEL-487E. The event reports generated by the SEL relays during Hardware-in-the-Loop testing are compared with the results obtained from the standalone testing and software model to validate the model. / <p>QC 20130215</p>
22

Lithology constraints from seismic waveforms : application to opal-A to opal-CT transition

Maysami, Mohammad 05 1900 (has links)
In this work, we present a new method for seismic waveform characterization, which is aimed at extracting detailed litho-stratigraphical information from seismic data. We attempt to estimate the lithological attributes from seismic data according to our parametric representation of stratigraphical horizons, where the parameter values provide us with a direct link to nature of lithological transitions. We test our method on a seismic dataset with a strong diagenetic transition (opal-A to opal-CT transition). Given some information from cutting samples of well, we use a percolation-based model to construct the elastic profile of lithological transitions. Our goal is to match parametric representation for the diagenetic transition in both real data and synthetic data given by these elastic profiles. This match may be interpreted as a well-seismic tie, which reveals lithological information about stratigraphical horizons.
23

New inverse hydogel opals as protein responsive sensors

Sütterlin, Martin January 2013 (has links)
In this work, the development of temperature- and protein-responsive sensor materials based on biocompatible, inverse hydrogel opals (IHOs) is presented. With these materials, large biomolecules can be specifically recognised and the binding event visualised. The preparation of the IHOs was performed with a template process, for which monodisperse silica particles were vertically deposited onto glass slides as the first step. The obtained colloidal crystals with a thickness of 5 μm displayed opalescent reflections because of the uniform alignment of the colloids. As a second step, the template was embedded in a matrix consisting of biocompatible, thermoresponsive hydrogels. The comonomers were selected from the family of oligo(ethylene glycol)methacrylates. The monomer solution was injected into a polymerisation mould, which contained the colloidal crystals as a template. The space in-between the template particles was filled with the monomer solution and the hydrogel was cured via UV-polymerisation. The particles were chemically etched, which resulted in a porous inner structure. The uniform alignment of the pores and therefore the opalescent reflection were maintained, so these system were denoted as inverse hydrogel opals. A pore diameter of several hundred nanometres as well as interconnections between the pores should facilitate a diffusion of bigger (bio)molecules, which was always a challenge in the presented systems until now. The copolymer composition was chosen to result in a hydrogel collapse over 35 °C. All hydrogels showed pronounced swelling in water below the critical temperature. The incorporation of a reactive monomer with hydroxyl groups ensured a potential coupling group for the introduction of recognition units for analytes, e.g. proteins. As a test system, biotin as a recognition unit for avidin was coupled to the IHO via polymer-analogous Steglich esterification. The amount of accessible biotin was quantified with a colorimetric binding assay. When avidin was added to the biotinylated IHO, the wavelength of the opalescent reflection was significantly shifted and therefore the binding event was visualised. This effect is based on the change in swelling behaviour of the hydrogel after binding of the hydrophilic avidin, which is amplified by the thermoresponsive nature of the hydrogel. A swelling or shrinking of the pores induces a change in distance of the crystal planes, which are responsible for the colour of the reflection. With these findings, the possibility of creating sensor materials or additional biomolecules in the size range of avidin is given. / In dieser Arbeit wird die Entwicklung von temperatur- und proteinresponsiven Sensormaterialien auf Basis von biokompatiblen, inversen Hydrogelopalen (IHO) vorgestellt, mit welchen die spezifische Erkennung größerer Biomoleküle visuell ausgelesen werden kann. Die Darstellung der IHOs erfolgte mittels Templatverfahren, bei dem im ersten Schritt monodisperse Silicapartikel vertikal auf Objektträger abgeschieden wurden. Die so erhaltenen Kolloidkristalle mit einer Dicke von 5 μm zeigten opaleszente Reflexionen aufgrund der gleichförmigen Anordnung der Partikel. Im zweiten Schritt wurde das Templat in eine Matrix aus biokompatiblen, thermoresponsiven Hydrogelen eingebettet. Die Comonomere wurden aus der Familie der Oligo(ethylenglykol)methacrylate ausgewählt. Zur Synthese des Hydrogels wurde die Monomerlösung in eine Polymerisationsform injiziert, welche die Kolloidkristalle als Templat beinhaltete. Die Zwischenräume der Templatpartikel wurden mit der Monomerlösung gefüllt und das Hydrogelnetzwerk per UV-Polymerisation erhalten. Die Templatpartikel wurden anschließend nasschemisch heraus gelöst, so dass eine poröse innere Struktur erhalten wurde. Die regelmäßige Anordnung der Poren und damit die opaleszenten Reflexionen wurden dabei beibehalten, so dass diese Systeme als inverse Hydorgelopale bezeichnet werden. Ein Porendurchmesser von mehreren hundert Nanometer, sowie durchgängige Verbindungskanäle zwischen den einzelnen Poren sollten eine Diffusion von großen (Bio)molekülen erleichtern, was bei bisherigen Systemen ein Problem darstellte. Die Copolymerzusammensetzung wurde dabei so gewählt, dass ein Kollaps des Hydrogels über 35 °C stattfand. Alle Hydrogele zeigten ausgeprägte Quellung in Wasser unterhalb der kritischen Temperatur. Der Einbau von reaktiven Comonomeren mit Hydroxylgruppen gewährleistete dabei die Funktionalisierbarkeit des Hydrogels mit Erkennungsgruppen für entsprechende Analytmoleküle, wie z.B. Proteine. Als Testsystem wurde Biotin als Erkennungseinheit für Avidin in das Hydrogel mittels polymeranaloger Steglich Veresterung eingebaut. Die Menge an zugänglichem Biotin wurde dabei per colorimetrischem Bindungsassay quantifiziert. Dabei zeigte sich, dass sich die Wellenlänge der Reflexion nach Zugabe von Avidin zum biotinylierten inversen Hydrogelopal signifikant verschob und damit das Bindungsereignis visuell auslesbar ist. Dieser Effekt beruht auf dem veränderten Quellungsverhalten des Hydrogels nach Bindung des hydrophilen Proteins Avidin in Wasser, welches durch den thermosresponsiven Charakter des Hydrogels verstärkt ist. Ein Aufweiten oder Schrumpfen der Poren ändert die Abstände der gleichmäßig angeordneten Poren, welche für die Farbe des inversen Opals verantwortlich sind. Auf Basis dieser Erkenntnisse lassen sich möglicherweise Sensormaterialen für die Erkennung weiterer Biomoleküle in der Größenordnung von Avidin erstellen.
24

Archaeometrical Investigation Of Some Seljuk Plasters

Caner, Evin 01 January 2003 (has links) (PDF)
The aim of the study was to investigate Seljuk Plasters used in some of their royal administrative or residential buildings from a viewpoint of their raw materials and technological characteristics. Some Byzantine Plasters of the same period were also investigated to make comparison. Plasters from some historic structures in the archaeological sites namely / Alanya Castle, Kubadabad Palaces, Syedra Archaeological Site, Aspendos Amphitheatre, Selinus Archaeological Site-Sekerhane K&ouml / sk and Hasbah&ccedil / e were examined. In a series of examination basic physical properties of the plasters as bulk density, porosity, water absorption capacity and water vapour permeability were obtained. The results indicated that plasters are low dense and high porous materials and having good breathing property. Mechanical properties of the plasters were expressed by the modulus of elasticity (Emod) values which were obtained from ultrasonic pulse velocity measurements. The Emod of the plasters being in the range of 1.0 to 5.6 Gpa show that they have enough mechanical strength comparable to historic mortars and bricks. Raw material composition and mineralogical properties of plasters were determined by combined interpretation of several types of analyses such as chemical analyses, particle size distribution of aggregates, petrographic analyses of thin sections by optical microscopy, scanning electron microscopic analyses of cross sections coupled with EDX for image analyses and semiquantitative elemental analyses, X-ray powder diffraction analyses for the determination of mineral phases, thermogravimetric analyses and FTIR analyses. Binder used in all plasters was found to be lime with amount in the range of 53.8-96.8% as CaCO3. The main minerals of aggregates are quartz, calcite (limestone), dolomite and opal-A. Regarding particle size distribution of aggregates it was possible to classify them into fine, coarse and mixed aggregates having rather high pozzolanicity. Study on decorative and red zigzag patterned plasters indicated presence of haematite as the source of red pigment. Study on green colored plaster also indicated presence of iron containing mineral with lower oxidation state. The Seljuk and Byzantine Masonries chosen are still surviving buildings that their plasters should be of good quality. In fact, this study approved their quality which may be due to the presence of opal-A and dolomite.
25

Lithology constraints from seismic waveforms : application to opal-A to opal-CT transition

Maysami, Mohammad 05 1900 (has links)
In this work, we present a new method for seismic waveform characterization, which is aimed at extracting detailed litho-stratigraphical information from seismic data. We attempt to estimate the lithological attributes from seismic data according to our parametric representation of stratigraphical horizons, where the parameter values provide us with a direct link to nature of lithological transitions. We test our method on a seismic dataset with a strong diagenetic transition (opal-A to opal-CT transition). Given some information from cutting samples of well, we use a percolation-based model to construct the elastic profile of lithological transitions. Our goal is to match parametric representation for the diagenetic transition in both real data and synthetic data given by these elastic profiles. This match may be interpreted as a well-seismic tie, which reveals lithological information about stratigraphical horizons.
26

Bestimmung der Masse und Breite des W-Bosons im semileptonischen Zerfallskanal mit dem OPAL-Detektor bei LEP

Vollmer, Cornelius Fritz. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2004--München.
27

Colour reconnection in hadronischen W-Paar-Zerfällen

Sahr, Oliver. Unknown Date (has links)
Universiẗat, Diss., 2001--München.
28

Measurement of the W boson mass in the W+W- -] qqln channel with the OPAL detector at LEP

Dubbert, Jörg. Unknown Date (has links)
University, Diss., 2001--München.
29

Suche nach der Produktion von einzelnen Leptoquarks oder Squarks in Elektron-Photon-Wechselwirkungen mit dem OPAL-Experiment

Stoll, Karina. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2000--Freiburg (Breisgau).
30

Untersuchung der Produktion charmhaltiger Mesonen in der Photon-Photon-Streuung mit dem OPAL-Experiment

Patt, Jochen. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2000--Freiburg.

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