Thesis (Ph. D.)--University of Alabama at Birmingham, 1998. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 110-115).

Thesis (Ph. D.)--University of Alabama at Birmingham, 1998. / Includes bibliographical references.

Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thèse (Ph. D.)--Université Laval, 2003. / Bibliogr. Publié aussi en version électronique.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Chemistry, 2004. / Includes bibliographical references.

Techn. Universiẗat, Diss., 2004--Darmstadt.

Thesis (MScEng)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: This thesis investigates the credibility of the vanadium redox flow energy storage system, sometimes termed vanadium redox battery (VRB). The focus is on the use of this technology in peak-shaving and load-leveling applications. The initial problem is to find a suitable mathematical model for representing the daily load profile. A sinusoidal function is identified as an elementary approximation of the first order. Due to the periodicity characteristics that are inherent in a daily load profile, the Fast Fourier Transform (FFT) algorithm is identified as a mathematical model that closely resembles a load profile. The main theme in this thesis is the determination of an optimal solution during the peak-shaving process. In this particular context, the optimal solution refers to the following: With the energy capacity of the VRB and the power rating of the entire system considered as the constraints, the interest is on (i) the constant power that the VRB can deliver in order to bring down the maximum demand quite significantly, (ii) and the time interval in which this constant power is delivered. Therefore, the VRB power delivered during peak-shaving (PVRB) and the corresponding time interval are the main two parameters under consideration in the optimization process. The mathematical algorithm that can be used to determine suitable values for these two parameters is developed. Maple" V 5.1 is used for determining the solution analytically. The obtained results are verified by simulation with Excel". The investigation into the economic benefits that may be derived from the utilization of the vanadium energy storage device is also presented. / AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek die waarde en toepassing van die vadium "redox" vloei energie stoorstelsel (VRB). Die fokus is op die gebruik van hierdie tegnologie om pieklas te verminder en om laste meer egalig te maak. Die aanvanklike probleem is om 'n geskikte wiskundige model vir die daaglikse las-profiel te kry. Deur gebruik te maak van sinus-komponente en die toepassing van die Vinnige Fourier Transform (FFT) is hierdie probleem opgelos. Die hooftema van hierdie werk is om 'n analitiese oplossing te vind vir die optimale toepassing van die konsep vir pieklas vermindering. In hierdie konteks verwys die optimale oplossing na die volgende: Met die gegewe verrnoe van die VRB stelsel en drywingsvermoe van die kragelektronika is die vrae rondom (i) die konstante drywing wat die VRB kan lewer om die maksimum aanvraag van die las beduidend te verminder en (ii) die tydsduur waarin dit plaasvind. Dus is die twee veranderlikes waarvoor oplossings in die optimale proses gesoek word die drywing (PVRS) en die tyd-interval daarvan. Die wiskundige algoritme is met die hulp van Maple® V5.1 ontwikkel. Die resultate is daarna met behulp van simulasies in Excel® getoets. 'n Analise van die moontlike ekonomiese voordele is ook ondersoek.

Este trabalho, realizado em cooperação com a Gerdau Riograndense, tem por finalidade avaliar o comportamento do aço GG1013-M, um aço baixo teor de carbono microligado com vanádio e manganês, na laminação a quente no que tange a sua resistência à deformação, possibilitando assim a tomada de decisão em relação a modificações no processo. Foram realizados testes em simulador termomecânico Gleeble™ para determinação das temperaturas a serem usadas no teste prático no laminador, onde testou-se lotes que cobrissem toda a amplitude da faixa de composição química da qualidade do aço em estudo. No teste prático no laminador, foram retiradas amostras para os ensaios mecânicos, onde identificou-se, por intermédio do tratamento de dados em software estatístico, a influência da variação dentro da faixa da composição química sobre os limites de escoamento e resistência. Como resultado, conseguiu-se determinar a faixa de temperatura mais provável, onde a resistência a deformação a quente é menor, minimizando ou eliminando as conseqüências da redução de ductilidade a quente por conta do endurecimento da matriz por precipitação dos elementos de liga em forma de compostos. / This work was conducted in cooperation with Gerdau Riograndense aiming at the evaluation of the hot rolling behavior of a low carbon steel microalloyed with manganese and vanadium (internally GG1013-M steel).The deformation resistance was evaluated, allowing for the decision in relation to changes in the process. A thermomechanical simulator GleebleTM was used to determine the temperatures to be used in practical tests in the rolling mill, where it was tested different material batches covering the large range of chemical compositions for this kind of steel. Mechanical tests were performed on samples taken from the practical tests in the rolling mill. From this tests the influence of chemical composition variation on the yeld strength and maximum stress was studied. As a result, we were able to determine the most likely range of temperatures for a minimization of hot strentgh, therefore also minimizing or eliminating the consequences of the reduction in the hot ductility due precipitation hardening of the matrix.

[pt] A doença de Alzheimer é uma patologia multifatorial que, nos dias atuais, re-presenta a forma mais conhecida de demência em idosos. Baseado na hipótese me-tálica, pesquisas demonstraram que a interação de certos íons metálicos endógenos, como o Fe3+ e o Cu2+, com o peptídeo A beta provoca uma aceleração da formação de espécies oligoméricas e ainda contribui para o aumento do estresse oxidativo. Neste ínterim, a proposição de MPACs (do inglês, Metal-Protein Attenuating Coum-pounds, compostos atenuadores da interação metal-proteína) é uma abordagem pro-missora para evitar o progresso da demência, pois estas moléculas apresentam afi-nidade moderada por íons metálicos. Neste trabalho, sintetizaram-se três potencias MPACs hidrazônicos, INHOVA, 2PCAFUR e FUROVA e um complexo inédito de vanádio(IV), [VO(INHOVA)2(OH2)]·2HCl 1/2 MeOH (1), proposto como mo-delo de veículo para esses compostos. A caracterização destas moléculas foi possí-vel a partir de diferentes técnicas, como espectroscopia vibracional na região do infravermelho (IV), análise elementar (CHN), ressonância magnética nuclear de 1H (RMN de 1H), difração de raios-X em monocristal, ressonância paramagnética ele-trônica (EPR) e análise termogravimétrica (TGA). Os ligantes hidrazônicos não co-ordenados são suscetíveis à hidrólise, conforme estudado por espectroscopia de ab-sorção no UV-Vis. O complexo de vanádio (1), por outro lado, apresenta maior estabilidade, podendo atuar como veículo para esses e outros MPACs, preservando a integridade do ligante em solução. Neste contexto, complexos metálicos de vanádio tendo como ligantes INHOVA, 2PCAFUR e FUROVA se apresentam como bons candidatos a estudos mais aprofundados, a fim de avaliar sua viabilidade como possíveis carreadores de MPACs no tratamento da doença de Alzheimer. / [en] Alzheimer s disease is a multifactorial pathology that, currently, represents the most known form of dementia in the elderly. Based on the metal hypothesis, studies have shown that the interaction of certain endogenous metal ions, such as Fe3 plus and Cu2 plus, with the A beta peptide accelerates the formation of oligomeric species and also contributes to the increase of oxidative stress. In this context, the proposition of MPACs (Metal-Protein Attenuating Compounds) is a promising approach to prevent the progression of dementia because these molecules exhibit moderate affinity for metal ions. In this work, three potential hydrazonic MPACs were syn-thesized, INHOVA, 2PCAFUR and FUROVA and a novel vanadium(IV) complex, [VO(INHOVA)2(OH2)] 2HCl.1/2MeOH (1), proposed as vehicle model for these compounds. The characterization of these molecules was possible from different techniques such as vibrational spectroscopy in the infrared (IR) region, elemental analysis (CHN), proton nuclear magnetic resonance (1H-NMR), X-ray diffraction in monocristal, electronic paramagnetic resonance (EPR) and thermogravimetric analysis (TGA). Uncoordinated hydrazonic ligands are susceptible to hydrolysis as studied by UV-Vis absorption spectroscopy. The vanadium complex (1), on the other hand, present greater stability, being able to act as vehicle for this and other MPACs, preserving their integrity in solution. In this context, vanadium metal com-plexes containing INHOVA, 2PCAFUR and FUROVA as ligands present them-selves as good candidates for further studies in order to evaluate their viability as possible drugs for the treatment of Alzheimer s disease.