Synthesis and characterization of thiophene ended poly-&amp / #949 / -caprolactone (PCL) and oxalic acid dithiophen-3-yl methyl ester (ODME) and their copolymers with both pyrrole and thiophene were achieved. Chemical structure of the precursor polymer and monomer were investigated Redox behavior of polymer and monomers were determined by Cyclic Voltammetry (CV). Structural characterization of samples were carried out by 1H, 13C Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Conductivities of the films were measured by using four probe technique. Thermal analyses of conducting copolymers were investigated via Differential Scanning Calorimetry (DSC) and Thermal Gravimetry Analysis (TGA). The morphologies of the copolymer films were examined by Scanning Electron Microscopy (SEM). Electrochromic and spectroelectrochemical behavior of the copolymers were investigated, and their ability of employment in device construction has been examined.

In the recent years, environmental pollution becomes a health threatening issue for human beings. Technological developments introduce industrial wastes and heavy metals, and developments in agriculture introduce pesticides into the world that we live. All these toxic wastes accumulate in drinking water and food consumed by humans. Therefore, detection of toxic wastes in all kinds of environmental samples, and development of new detection techniques become an important issue. In this study, development of a protein-based biosensor for detection of heavy metals in environmental samples, by expressing genetically modified glutathione S-transferase (GST-(His)6) protein in E.Coli BL21 (DE3) expression system, was designed. Recombinant GST proteins was expressed in E.Coli BL21 (DE3) expression system and purified with Glutathione Sepharose 4B affinity column and Ni-NTA spin kit. GST activities were determined using the GST substrate 1-chloro-2,4-dinitrobenzene (CDNB). Protein expression was tested by SDS-PAGE and Western blot analysis. Product formation linearly increased up to 1 mM CDNB, 1 mM GSH, 1.7 &micro / g proteins in 0.05 M, pH 6.9 phosphate buffer in the final volume of 1.0 ml at 25&amp / #9702 / C. The Vmax and Km values for GST-(His)6 towards CDNB and GSH were calculated with Lineweaver-Burk as CDNB Vmax / 22.88 &micro / mol/min/mg, Km / 4.29 mM,and as GSH Vmax / 6.42 &micro / mol/min/mg, 24.45 &micro / mol/min/mg, Km / 3.69 mM, respectively. Biosensor working electrode was prepared by immobilizing the GST-(His)6 by 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride (EDC) coupling on the gold surface. Electrode preparation was confirmed by cyclic voltammetry measurements. The biosensor was inserted as the working electrode in the constructed three(four)-electrode flow cell. The conformational change resulting from the binding of the metal ions to the recombinant protein causing a capacitance change proportional to the concentration of the metal ions was determined. After the working electrode is standardized and calibrated, the heavy metal concentration in water samples was measured. The GST-(His)6 biosensor has a large operational range between 1 fM and 10 mM and a storage stability of approximately 2 weeks. The GST-(His)6 biosensor is very sensitive to, Cu+2&gt / Cd+2&gt / Zn+2&gt / Hg+2 metal ions, at low concentrations.

Thesis (M.S.)--Ohio University, August, 2006. / Title from PDF t.p. Includes bibliographical references.

Thesis (Ph.D.)-- University of Western Sydney, Nepean, 1999. / Includes bibliographical references (leaves 291-308).

Maîtrise (M.Eng.)--Université du Québec à Chicoutimi, 1998. / Document électronique également accessible en format PDF. CaQCU

Thèse (D.Eng.)--Université du Québec à Chicoutimi, 2000. / Document électronique également accessible en format PDF. CaQCU

Thesis (Ph.D.)--Ohio University, June, 2005. / Title from PDF t.p. Includes bibliographical references (p. 89-92)

Η ρύπανση του περιβάλλοντος και η εξάντληση των ορυκτών καυσίμων έχουν φέρει την ανάγκη για νέες ανανεώσιμες πηγές καυσίμων, όπως το υδρογόνο ειδικά όταν παραχθεί με ηλεκτρολυτική μέθοδο. Σ' αυτήν την εργασία, παρασκευάσαμε και αξιολογήσαμε ηλεκτρόδια(λεπτά υμένια) για την αποτελεσματική παραγωγή υδρογόνου. Χρησιμοποιήσαμε την ηλεκτροαπόθεση για την παρασκευή των λεπτών υμενίων σε υπόστρωμα χαλκού. Πιο συγκεκριμένα αποθέσαμε λεπτά υμένια με βάση το νικέλιο. Τα υμένια Ni-Fe, Ni-Zn, Ni-Co-Zn, Ni-Mo-Zn, Ni-Mo-Fe και Ni-Mo-Fe-Zn παρασκευάστηκαν με ηλεκτροαπόθεση. Τα ηλεκτρόδια χρησιμοποιήθηκαν ως κάθοδοι σε μια συσκευή ηλεκτρόλυσης τύπου Hoffmann, ώστε να εξεταστούν ως προς την παραγωγή υδρογόνου. Για περαιτέρω χαρακτηρισμό των ηλεκτροδίων πραγματοποιήθηκαν μετρήσεις υπερδυναμικού για αρκετές πυκνότητες ρεύματος. Μέσω των διαγραμμάτων Tafel λάβαμε χρήσιμα πειραματικά αποτελέσματα όπως η κλίση Tafel και η πυκνότητα ρεύματος ανταλλαγής. Τέλος εικόνες SEM μας έδωσαν πληροφορίες για τη μορφολογια και τις ηλεκτροκαταλυτικές ιδιότητες των λεπτών φιλμ. / The environmental pollution and the depletion of fossil fuels have brought the need for new renewable fuels, such as hydrogen, especially when it has been produced with electrolytic process. In this work, we report on the preparation and evaluation of special electrodes (thin film alloys) for high efficiency H2 production. We are using the electrochemical deposition method copper is used as substrate. In particular we have deposited films of the transition metal Ni on copper substrates. films Ni-Fe, Ni-Zn, Ni-Co-Zn, Ni-Mo-Zn, Ni-Mo-Fe and Ni-Mo-Fe-Zn are produced using the electrochemical deposition method. These electrodes are used as cathodes in an electrolyte cell of the Hoffmann type in order to examine their efficiency in producing hydrogen. Furthermore, in order to consider the individual characteristics of the electrodes, measurements of overpotentional for several current densities were taken. In addition to the previous measurements, the Tafel plot has given useful experimental results. The most important from the Tafel plot, is the Tafel slope and the exchange current density. Finally SEM images gave more accurate results on the morphology and the electrocatalytic properties of the thin film alloys.

Orientador: José Luz Silveira / Banca: Julio Santana Antunes / Banca: Ederaldo Godoy Junior / Resumo: Neste trabalho são estudados dois processos que utilizam biogás para obtenção do biohidrogênio. Inicialmente é analisado o processo de eletrólise da água, com o uso de energia elétrica gerada em conjunto motor de combustão interna/gerador (MCI) operando com biogás de aterro sanitário. Visando aproveitamento de calor dos gases de escape do MCI estuda-se o potencial de geração de energia térmica útil pela aplicação da técnica de cogeração. Considera-se dois casos: o primeiro para a produção de água quente em um trocador de calor, e o segundo, para a produção de água gelada em um sistema de refrigeração por absorção. Posteriormente é estudada a reforma a vapor de biogás para a produção de biohidrogênio, que utiliza também esse biocombustível para a geração de vapor superaquecido necessário ao processo de reforma. O objetivo é efetuar a análise energética de modo a determinar as eficiências dos processos, o potencial de produção de biohidrogênio, água quente ou água gelada, nos aterros sanitários da cidade de São Paulo. Também é efetuada análise de engenharia econômica para a determinação do custos da produção de biohidrogênio, água quente e água gelada, em US$/kWh. Esse estudo baseia-se em parâmetros tais como, investimento capital, custos de manutenção e operação dos equipamentos, período equivalente de utilização e período de amortização de capital. Em fase final, foram realizados estudos de impactos ambientais para a determinação das eficiências ecológicas dos processos de p... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this work is studied two processes to obtain hydrogen using biogas. Initially is analyzed the process of electrolysis of water, with the use of electricity generated in conjunction with an internal combustion engine / generator (ICE) operating with landfill biogas. generated by an internal combustion engine/generator operating with landfill biogas, is analyzed. In order to take advantage of the exhaust gases from the combustion of biogas, the potential of cogeneration is studied, another two cases are considered. The first one studies the production of hot water in the heat exchanger and the second analyzes the use of absorption refrigeration system to produce cold water. Subsequently it is studied the steam reform of biogas for the production of hydrogen, which is constituted of biogas burning for the generation of superheated steam used in the conversion of the fuel input. The objective is to make the energy analysis in order to determine the efficiency of the processes and the potential of producing hydrogen, hot water or ice water in the landfills of the city of São Paulo using the biogas generated. An economic engineering analysis to determine the production hydrogen cost, hot water and ice water, in US$/kWh, based on capital investment, maintenance and operation costs, equivalent period of use and payback. In the final phase, environmental study method is applied to determine the ecological efficiencies of the hydrogen production processes using biogas, considering ... (Complete abstract click electronic access below) / Mestre

Este trabalho contém um estudo experimental para a obtenção e a validação de um combustível à base de água, obtido através da eletrolise desta e denominado de HHO (Gás de Brown), a ser utilizado como auxiliar na queima de hidrocarbonetos dos demais combustíveis fósseis e de fontes renováveis como o álcool hidratado (etanol). Para a realização deste trabalho foi utilizado um eletrolisador composto por placas de aço inox 316L e eletrólito à base de hidróxido de potássio, conjunto este de eletrólito em sua concentração ideal, material de construção do eletrolisador determinado através de estudo prévio em bibliografia. Posto o sistema em funcionamento, realizado a análise exergética da composição e do gás gerado, onde se verificou a existência de energia disponível para gerar trabalho útil e que o maior desperdício se encontrava na potência elétrica utilizada para a produção do gás. Após esta validação o gás foi submetido a testes em dinamômetro de desempenho e emissões com motores de combustão interna com deslocamento de 1,6 litros, porém com configurações diferentes de alimentação. Para que os dados refletissem a utilização de maior demanda de combustível, como no trânsito urbano, foram escolhidas as rotações de 1500rpm, 2500rpm e 3500rpm, com aberturas de borboleta em dois estágios, total 100% e abertura parcial a 40%. As variáveis controladas foram a potência, o torque, o consumo instantâneo de combustível, o fator lambda (λ) e a emissão dos gases CO, CO2 e HC. Em ambos os testes, aberturas total e parcial, com suas respectivas particularidades de no sistema de alimentação, foram apresentadas tendências de melhora em desempenho e reduções de emissões, devido aos valores obtidos estarem dentro das incertezas de medição no caso do sistema de alimentação por carburador e combustível principal o álcool hidratado, contudo no caso do sistema de alimentação por injeção eletrônica programável à gasolina comercial, com injeção de gás individualizada os resultados apresentados ficaram moderadamente acima das incertezas de medição. Entretanto, o sistema utilizado no experimento com gasolina + HHO e injeção programável, apresentou uma redução de emissões de CO em 26,4% (abertura parcial) e 18,6% (abertura total), reduzindo as emissões de HC em 16% (abertura parcial) e 14,5% (abertura total) e, por sua vez, o consumo de combustível reduziu em 29,6%. / This work contains an experimental study to obtain and validate a water-based fuel obtained through the electrolysis of this one and denominated HHO (Brown Gas), to be used as an auxiliary in the hydrocarbon burning of other fossil fuels and renewable sources such as hydrated alcohol (ethanol). For this work, an electrolyzer composed of 316L stainless steel plates and electrolyte based on potassium hydroxide was used, this electrolyte assembly in its ideal concentration, electrolyte construction material determined through a previous bibliography study. After the system was in operation, the exergy analysis of the composition and generated gas was performed, where the existence of available energy to generate useful work was verified and that the greatest waste was in the electric power used for the production. After this validation the gas was submitted to dynamometer tests of performance and emissions with engines of internal combustion with displacement of 1.6 liters, but with different feeding configurations. For the data to reflect the use of higher fuel demand, such as in urban traffic, the revolutions of 1500rpm, 2500rpm and 3500rpm were chosen, with twostage butterfly apertures, total 100% and partial opening at 40%. The variables controlled were power, torque, instantaneous fuel consumption, lambda factor (λ) and emission of CO, CO2 and HC gases. In both tests, total and partial openings, with their respective peculiarities of the feed system, presented trends of improvement in performance and emission reductions, due to the values obtained being within the uncertainties of measurement in the case of the carburetor feed system and the main fuel is the hydrated alcohol, however in the case of the commercial gasoline programmable electronic fuel injection system with individualized gas injection the presented results were moderately above the measurement uncertainties. However, the system used in the experiment with gasoline + HHO and programmable injection showed a reduction of CO emissions by 26.4% (partial opening) and 18.6% (total opening), reducing HC emissions by 16% ( partial opening) and 14.5% (total opening) and, in turn, fuel consumption decreased by 29.6%.