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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.
61

Desenvolvimento de métodos eletroanalíticos empregando análise por injeção em batelada para a determinação de nafazolina, zinco, feniramina e clorfeniramina em formulações farmacêuticas

Oliveira, Thiago da Costa 24 July 2015 (has links)
Fundação de Amparo a Pesquisa do Estado de Minas Gerais / In this work we investigated the potentiality of batch injection analysis with square-wave voltammetry (BIA-SWV) detection for simultaneous determination of Zn and naphazoline (NAF) and batch injection analysis with multiple pulse amperometric (BIA-MPA) detection for simultaneous determination of NAF and pheniramine (FEN) or NAF and chlorpheniramine (CLO). In both methods, boron-doped diamond (BDD) was used as working electrode. For the simultaneous determination of Zn and NAF by BIA-SWV, the following conditions have been optimized: supporting electrolyte: acetate buffer 0.05 mol L-1 (pH = 4.7), injection volume: 100 μL, deposition time (Zn): 5 s, deposition potential (Zn) -1.5 V, : 100 s-1, a: 60 mV, ΔEs: 6 mV. Under these conditions, the method showed linear response range between 10 and 60 μmol L-1 for Zn (r = 0.992) and between 3.0 e 21 μmol L-1 for NAF (r = 0.999), high analytical frequency (70 injections h-1) and LOD of 0.126 μmol L-1 and 0.04 μmol L-1 for Zn and NAF, respectively. In the study of repeatability (n = 20), the calculated RSD were 0.98% and 0.97% for Zn and NAF, respectively. The simultaneous determination of NAF and FEN or NAF and CLO by BIA-MPA was performed with the application of three sequential pulses in function of time to the BDD electrode using Britton-Robinson Buffer solution 0.12 mol L-1 (pH = 10.0) as supporting electrolyte. At +1.1 V/50 ms, FEN or CLO was detected (oxidation) without interference of NAF. At +1.3 V/50 ms, both compounds (FEN + NAF or CLO + NAF) were oxidized. The current of NAF can then be obtained by subtraction of the currents detected during application of both potential pulses using a correction factor. The proposed method presented good ability (RSD = 1.7 and 4.0% for FEN and NAF; 2.1% and 3.6% for CLO and NAF, respectively; n=20); high analytical frequency (110 injections h-1), linear concentration range between 16 e 100 μmol L-1 for FEN and CLO (r > 0.996) and between 2 e 15 μmol L-1 for NAF (r > 0.997). The LOD calculated were 0.367, 0.361 e 0.148 μmol L-1, for FEN, CLO and NAF, respectively. The proposed methods were used for determination of these compounds in pharmaceutical samples. The obtained results were statistically similar to that obtained by HPLC (NAF, FEN and CLO) and atomic spectroscopy (Zn). / No presente trabalho investigou-se a potencialidade do sistema de análise por injeção em batelada com detecção por voltametria de onda quadrada (BIA-SWV) para determinação simultânea de Zn e nafazolina (NAF) e do sistema análise por injeção em batelada com detecção por amperometria de múltiplos pulsos (BIA-MPA) para determinação simultânea de NAF e feniramina (FEN) ou NAF e clorfeniramina (CLO). Em ambos os métodos, diamante dopado com boro (BDD) foi usado como eletrodo de trabalho. Para determinação simultânea de Zn e NAF empregando BIA-SWV, as seguintes condições foram otimizadas: eletrólito de suporte: tampão acetato 0,05 mol L-1 (pH = 4,7), volume de injeção: 100 μL, tempo de deposição (Zn): 5 s, potencial de deposição (Zn): -1,5 V, : 100 s-1, a: 60 mV, ΔEs: 6 mV. Nestas condições, o método apresentou faixa linear de resposta entre 10 e 60 μmol L-1 para Zn (r = 0,992) e entre 3,0 e 21 μmol L-1 para NAF (r = 0,999), frequência analítica de 70 injeções h-1 e limites de detecção de 0,126 μmol L-1e 0,04 μmol L-1 para Zn e NAF, respectivamente. No estudo de repetibilidade (n = 20), os DPRs foram calculados 0,98% e 0,97% para Zn e NAF, respectivamente. A determinação simultânea de NAF e FEN ou NAF e CLO por BIA-MPA foi realizada através da aplicação de dois pulsos de potenciais em função do tempo ao eletrodo de BDD usando tampão BR 0,12 mol L-1 (pH = 10) como eletrólito suporte. Em +1,1 V/50 ms, FEN ou CLO foram oxidadas livre da interferência de NAF. Em +1,3 V/50ms, ambos os compostos (NAF + FEN ou NAF + CLO) foram oxidados. A corrente proveniente da oxidação da NAF foi obtida pela subtração entre as correntes detectadas em ambos os pulsos de potenciais com auxílio de um fator de correção (FC). O método proposto apresentou boa estabilidade (DPR = 1,7 e 3,95% para FEN e NAF; 2,1 e 3,6% para CLO e NAF, respectivamente; n=20), alta frequência analítica (110 injeções h-1), faixa linear de resposta entre 16 e 100 μmol L-1 para FEN e CLO (r > 0,996) e entre 2 e 15 μmol L-1 para NAF (r > 0,997). Os limites de detecção foram de 0,367, 0,361 e 0,148 μmol L-1 para FEN, CLO e NAF, respectivamente. Os métodos propostos foram usados na determinação destes compostos em formulações farmacêuticas. Os resultados obtidos com os métodos propostos foram estatisticamente similares aos obtidos por HPLC (NAF, FEN e CLO) ou absorção atômica (Zn). / Mestre em Química
62

Nové přístupy k chemické modifikaci diamantových povrchů / Novel approaches to chemical modification of diamond surface

Bartoň, Jan January 2020 (has links)
1 Abstract Diamond is a unique material for its physical and chemical stability. However, many advance applications rely on surface functionalisation. Here, two types of diamond were modified on the surface - thin layer of chemical vapor deposition (CVD) and nanodiamond particles (NDs) high pressure and high temperature (HPHT). The aim of CVD surface modification was to prepare photosensitised, conductive, diamond electrodes for dye sensitized solar cells (DSSC). For this purpose, a thin diamond layer doped with boron was deposited on the silicon wafer. Boron doping provided p-type (semi)conductivity to diamonds. The surface of the diamond was hydrogenated with H-plasma, and a short carbon linker with a protected amino group was UV-photografted to the surface. In another study, a photoconverting dye (P1) was covalently attached to the amine-linker. Furthermore, a dye designed based on donor-π-acceptor (D-π-A) concepts was attached to the surface. Finally, a systematic study was done for differently conductive diamond layer and the underlying silicon wafer These experiments gradually lead to the highest ever reported photocurrents of 6.6 µA cm2 for a flat photosensitised boron-doped-diamond (BDD) electrode. Monomolecular layer surface functionalizations on CVD diamond are difficult to detect or even quantify...
63

Padan 95 SP treatment by electrochemical process and its combination with other techniques

Nguyen Tien, Hoang 06 November 2019 (has links)
This dissertation describes electrochemical oxidation of Padan 95 SP on Boron-doped diamond (BDD) electrode mainly by •OH radicals (which was measured by indirect method, i.e: the formation of 2-Hydroxylterephthalic acid (2-HTA)), Electro-Fenton and the combination with adsorption technology for increasing total organic carbon (TOC) removal efficiency. In this study, the formation of 2-HTA on BDD electrode via the reaction between terephthalic acid (TA) and •OH as a method to quantify hydroxyl radical formation was investigated. The degradation of Cartap in Padan 95SP (95 % Cartap) on BDD was investigated. Operating parameters such as applied current density, types of electrolyte and initial concentration of Padan 95SP were varied in order to determine their effect on the degradation efficiency of Cartap. The concentration of Cartap was determined by UV-Vis spectroscopy according to 5,5-Dithiobis-(2-nitrobenzoic acid) (DTNB) procedure. High Performance Liquid Chromatography (HPLC) and Gas Chromatography/Mass Spectrometry (GC-MS) were used to characterize the commercial Padan 95SP and the formation of by-products. The optimal conditions for Cartap degradation by electrochemical process have been established: concentration of electrolyte: 0.05 M Na2SO4, initial concentration of Padan 95SP: 300 mg·L-1, pH = 3, current density: j = 20 mA·cm-2. At this condition, Cartap decreases to 41 %, TOC decay reaches 8 %. To increase TOC decay at higher Padan 95 SP concentration in aqueous solution, the combination technique of electrochemical process with other techniques was proposed, e.g.: Electro-Fenton technique, pre-oxidizing by NaOCl or the Electro-Adsorption combination. In the Electro-Fenton technique, we investigated the influence of factors such as the presence of NaOCl in pretreatment of process, affects of H2O2 concentration, Fe2+ dosage, co-catalysts metals ion and pH. The efficiency shows approximately 80 % of TOC removed at 700 mg·L-1 Padan 95 SP. The combination of electrochemical with adsorption method shows the efficient removals of TOC and Padan 95SP (95 % Cartap) based on reagents oxidation in electrochemical process and adsorption of granular activated carbon (GAC), respectively. The influence of factors such as supporting electrolytes, flow rate, bed height, recycling number as well as initial concentration were investigated in order to determine their effects on TOC removal. The efficiency of this combination shows approximately 75 % of TOC and more than 90 % of Cartap removed at 700 mg·L-1 Padan 95 SP. Fourier Transform Infrared (FT-IR) and (Brunauer–Emmett–Teller) BET surface analysis were applied to investigate GAC before and after usage. The results have shown that the application of electrochemical technique with other methods can be the potential option for treatment of wastewater containing Padan 95 SP. / Diese Dissertation befasst sich mit der Reduktion des gesamten organischen Kohlenstoffs (TOC) aus wässriger Lösung, die Padan 95 SP enthält. Als Methoden zur Minimierung von TOC wurden die elektrochemische Oxidation von Padan 95 SP auf Bor-dotierter Diamant (BDD) Elektroden durch •OH Radikale, Elektro-Fenton und die Kombination mit Adsorptionstechnologien verwendet. Die •OH Radikale wurden dabei durch indirekte Methoden, z. B. die Bildung von 2-HTA gemessen. Zur Quantifizierung der Hydroxylradikalbildung wurde in dieser Studie die Bildung von 2-Hydroxylterephthalsäure (2-HTA) an BDD-Elektroden über die Reaktion zwischen Terephthalsäure (TA) und •OH untersucht. Weiterhin befasst sich die Arbeit mit dem Abbau von Cartap in Padan 95SP (95% Cartap) auf BDD über die Reaktion zwischen Cartap und Hydroxylradikalen. Betriebsparameter wie die angewandte Stromdichte, die Elektrolytarten und die Anfangskonzentration von Padan 95SP wurden variiert, um ihre Wirkung auf die Abbaueffizienz von Cartap zu bestimmen. Die Konzentration von Cartap wurde mittels UV-Vis-Spektroskopie mit dem 5,5-Dithiobis-(2-Nitrobenzoesäure) (DTNB) Verfahren bestimmt. Hochleistungs-Flüssigkeitschromatographie (HPLC) und Gaschromatographie/Massenspektrometrie (GC-MS) wurden verwendet, um das kommerziell erhältliche Padan 95SP und die Bildung von Nebenprodukten beim Abbau von Cartap zu charakterisieren. Die optimalen Bedingungen für die Cartap-Degradation durch den elektrochemischen Prozess wurden festgelegt: Konzentration des Elektrolyten: 0.05 M Na2SO4, Padan 95SP Anfangskonzentration: 300 mg·L-1, pH = 3, Stromdichte: j = 20 mA·cm-2. Unter diesen Bedingungen sinkt Cartap auf 41% und der TOC erreicht 8 % des jeweiligen Ausgangswertes. Um den TOC-Zerfall bei höher Padan 95 SP Konzentration in Wasser zu erhöhen, wurde die Kombination des elektrochemischen Prozesses mit anderen Techniken vorgeschlagen, z.B.: Elektro-Fenton-Technik, Oxidation mit NaOCl, oder die Kombination des elektrochemischen Prozesses mit einem Adsorptionsprozess. Bei der Elektro-Fenton-Technik wurde der Einfluss von Faktoren wieder Anwesenheit von NaOCl in der Prozessvorbehandlung, Auswirkungen der H2O2-Konzentration, Fe2+-Dosierung, Metallionen als Cokatalysatoren und der pH-Wert der Lösung untersucht, um die Wirkung auf die Abbau-Effizienz für Cartap zu bestimmen. Es konnten mit dieser Methode rund 80 % TOC, ausgehend von 700 mg·L-1Padan 95SP, entfernt werden. Die Kombination des elektrochemischen Prozesses mit einer Adsorptionsmethode ermöglicht eine effiziente Entfernung von TOC und Padan 95SP (95% Cartap). Dies basiert auf der Oxidation und anschließender Adsorption auf granularer Aktivkohle (GAC). Der Einfluss von Faktoren wie Leitelektrolyten, Flussrate, Betthöhe, Recyclingzahl sowie die Anfangskonzentration von Padan 95 SP wurde untersucht, um deren Auswirkungen auf die TOC Entfernung zu bestimmen. Durch die Kombination konnten so 75% desTOC und mehr als 90% Cartap bei 700 mg·L-1Padan 95 SP entfernt werden. Fourier-Transformations-Infrarot (FT-IR) und BET-Oberflächenanalyse wurden angewendet, um GAC vor und nach der Verwendung zu untersuchen. Die Ergebnisse haben gezeigt, dass die Kombination des elektrochemischen Prozesses mit anderen Methoden eine potentielle Option für die Behandlung von Abwasser, das Padan 95 SP enthält, sein kann.
64

Microscopie électrochimique pour l'élaboration et la caractérisation de bio-assemblages sur électrode : application aux biopuces

Fortin, Elodie 14 November 2005 (has links) (PDF)
L'objectif de ce travail est double : (i) la détection électrochimique des nucléosides sur<br />un nouveau matériau carboné d'électrode, le diamant dopé bore (BDD), et (ii) l'utilisation<br />d'un nouvel outil, la microscopie électrochimique à balayage (SECM), afin de fonctionnaliser<br />des surfaces avec des sondes oligonucléotidiques et de détecter le phénomène d'hybridation.<br />Dans un premier temps, nous montrerons la dualité d'utilisation de la microscopie<br />électrochimique en tant qu'outil de fonctionnalisation et de caractérisation de surfaces. Par<br />mode direct de la SECM, en utilisant la microélectrode en tant que contre-électrode, des<br />spots de polypyrrole-oligonucléotide de taille micrométrique sont déposés sur un substrat<br />d'or. Cette méthode d'élaboration est optimisée en étudiant l'hybridation des spots en<br />microscopie de fluorescence. La présence de ces spots sur la surface est ensuite détectée en<br />mode feedback de la SECM via la différence de conductivité entre le polypyrroleoligonucléotide<br />et l'or. Puis, le phénomène d'hybridation est étudié par mode feedback par la<br />précipitation d'un produit isolant sur la surface formé par une réaction catalysée par la<br />peroxydase couplée par l'intermédiaire d'un assemblage biologique à l'oligonucléotide<br />complémentaire. Enfin, cette technique électrochimique est couplée à une méthode optique,<br />l'imagerie de résonance plasmonique de surface (SPRi), afin de visualiser en temps réel<br />l'étape de structuration de la surface d'or par des spots d'oligonucléotides ou par des<br />gradients de surface d'oligonucléotides.<br />Dans un second temps, nous présenterons l'étude des réactions d'oxydation des<br />nucléosides, la 2'-désoxyguanosine et la 2'-désoxyadénosine, sur une électrode de diamant<br />dopée bore oxygéné. Nous montrerons ainsi l'intérêt de ce nouveau matériau carboné<br />d'électrode pour cette application en raison de sa large fenêtre d'électroinactivité en milieu<br />aqueux et son faible et stable courant de fond. Puis, nous mettrons en évidence la formation<br />d'un film continu constitué des produits de ces réactions d'oxydation sur l'électrode par une<br />étude macroscopique à l'aide de voltamétries cycliques d'une sonde redox, et une étude à<br />l'échelle microscopique en utilisant le microscope électrochimique à balayage.
65

Integração da abordagem Domain-Driven Design e de técnica Behaviour-Driven Development no desenvolvimento de aplicações web

Santos, Eloisa Cristina Silva 01 June 2015 (has links)
Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2016-09-30T12:23:06Z No. of bitstreams: 1 DissECSS.pdf: 2536269 bytes, checksum: a856f5027d19c2aaadf2834a69af7ff4 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-09-30T17:56:23Z (GMT) No. of bitstreams: 1 DissECSS.pdf: 2536269 bytes, checksum: a856f5027d19c2aaadf2834a69af7ff4 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-09-30T17:56:32Z (GMT) No. of bitstreams: 1 DissECSS.pdf: 2536269 bytes, checksum: a856f5027d19c2aaadf2834a69af7ff4 (MD5) / Made available in DSpace on 2016-09-30T18:05:54Z (GMT). No. of bitstreams: 1 DissECSS.pdf: 2536269 bytes, checksum: a856f5027d19c2aaadf2834a69af7ff4 (MD5) Previous issue date: 2015-06-01 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / The agile methods of software development have emerged as an alternative to traditional approaches, to spend less time on documentation and more time with solving problems interactively and iteratively. In this context, the development approach Domain Driven Design (DDD) is a way of developing software in which the application design process is guided by a domain model. In conjunction with the DDD development approach, the existence of tests during the implementation of an application is required to ensure quality. Objective: This work aims to study the agile development approach Domain-Driven Design (DDD) and the software test techniques Test-Driven Development (TDD) and Behaviour-Driven Development (BDD). A case study was built to exemplify the integration of each test technique with DDD. The case study was developed with the support of the Apache Isis framework, from a well-defined domain model. Methodology: Based on the literature, the concepts of the DDD development approach and of the TDD and BDD test techniques, that provided the comparison between the techniques, and later, the implementation to illustrate this research, were extracted. The Apache Isis framework was used in this work because it allows develop DDD applications quickly. During the development of the sample system of this work, the possibility of creating an automatic generator tests and scenarios for BDD was noted. Results: A case study was created using the concepts of DDD and tests, with TDD and BDD. Furthermore, a prototype of tests and scenarios generator for software projects that use DDD, through the Apache Isis framework and tests using BDD, was developed. Conclusions: The combination of test techniques mentioned with DDD aim to boosting the development of applications, since DDD is not associate with any test technique. Writing scenarios with ubiquitous language is a great advantage to integrate DDD and BDD, because it allows a clear understanding for all involved in the project. Moreover, the creation of automatic generator speeds up the testing phase, and can detect errors that might go unnoticed or only be found as the project evolved. / Os métodos ágeis de desenvolvimento de software surgiram como uma alternativa às abordagens tradicionais, com o intuito de despender menos tempo com documentação e mais com a resolução de problemas de forma interativa e iterativa. Neste contexto, a abordagem de desenvolvimento Domain-Driven Design (DDD) representa uma forma de desenvolver software em que o processo de design de uma aplicação é guiado pelo modelo de domínio. Em conjunto com a abordagem de desenvolvimento DDD, a existência de testes durante a implementação de uma aplicação é necessária para garantir a qualidade. Objetivo: Este trabalho teve como objetivo o estudo da abordagem ágil de desenvolvimento Domain-Driven Design (DDD) e as técnicas de teste de software Test-Driven Development (TDD) e Behaviour-Driven Development (BDD). Um estudo de caso foi construído para exemplificar a integração de cada técnica de teste com o DDD. O estudo de caso foi desenvolvido por meio do framework Apache Isis, a partir de um modelo de domínio bem definido. Metodologia: Com base na literatura foram extraídos os conceitos da abordagem de desenvolvimento DDD e das técnicas de testes TDD e BDD que proporcionaram a comparação entre as técnicas e posterior implementação para exemplificar a pesquisa. O framework Apache Isis foi utilizado neste trabalho porque permite desenvolver aplicações com DDD de forma rápida. No decorrer do desenvolvimento do sistema exemplo deste trabalho, notou-se a possibilidade da criação de um gerador automático de testes e cenários para BDD. Resultados: Foi criado um estudo de caso empregando os conceitos de DDD e testes com o TDD e com o BDD. Além disso, foi desenvolvido um protótipo de gerador de testes e cenários para projetos de software que empregam DDD, por meio do framework Apache Isis e testes utilizando BDD. Conclusões: A junção das técnicas de testes citadas com o DDD visa potencializar o desenvolvimento de aplicações, uma vez que o DDD não aborda nenhuma técnica de teste. A escrita de cenários em linguagem ubíqua é um grande diferencial ao integrar DDD e BDD, pois permite um claro entendimento a todos os envolvidos do projeto. Ademais, a criação do gerador automático agiliza a fase de testes, sendo possível detectar erros que poderiam não ser notados ou apenas serem encontrados com a evolução do projeto.
66

Eletroxidação de cloranfenicol e outros poluentes organicos utilizando reatores eletroquimicos, constituidos de anodos tipo DSA ou de diamante dopado com boro (DDB) / Electrooxidation of chloramphenicol and otherpollutants using electrochemical reactors composed with a DSA type anode or a boron-doped diamond anode

Spitzer, Marcos 30 September 2005 (has links)
Orientador: Rodnei Bertazzoli / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-05T06:46:31Z (GMT). No. of bitstreams: 1 Spitzer_Marcos_D.pdf: 1019872 bytes, checksum: 57974ac02038eb53169c99987a119811 (MD5) Previous issue date: 2005 / Resumo: O método de oxidação eletroquímica foi aplicado a soluções aquosas contendo cloranfenicol (CAP) e outros compostos orgânicos. Para isso, utilizou-se um anodo de óxido condutor, comercial, tipo DSA®, de composição 70TiO2-30RuO2 e um anodo de diamante dopado com boro (DDB) tipo comercial. Cada anodo foi instalado em um reator tipo filtro-presa, em escala de bancada, para processamento de 2 a 3 L de solução em modo de batelo-reciclo. Inicialmente, nos reatores construídos foram realizados estudos voltamétricos, em modo hidrodinâmico. Sobre um catodo de aço inoxidável, antes da evolução de H2, observou-se a redução do grupo NO2 do CAP a HO-NH- a pH=5, e em potenciais anódicos, sobre o DSA®, observou-se o início reação de evolução de O2 a partir de 1 V vs. ECS e que a presença de CAP reduz as correntes de evolução de O2. Sobre o DDB, o CAP é oxidado a partir de 0,6 V resultado na passivação do anodo. A partir de 2,2 V observa-se o início da evolução de O2 sobre o DDB, resultando na eliminação do filme passivador. Em seguida, eletrólises exaustivas foram realizadas, em modo galvanostático, com ambos os anodos, dentro da região de evolução de O2. Cinéticas de pseudo-primeira ordem foram observadas dos decaimentos ds CAP sobre o DSA®, na faixa de 50 a 180 mA cm-2, e sobre o DDB, na faixa de 10 a 30 mA cm-2. Os decaimentos da demanda química de O2 (DQO) e do carbono orgânico total (COT) também apresentaram essa cinética quando as reações de oxidação sobre o DDB tornavam-se controladas pelos processos de transporte de massa. A partir de eletrólises de soluções de K2SO4 com o DDB observou-se a geração de H2O2. Os números adimensionais Sherwood (Se), Reynolds (Re) e Schmidt (Sc) foram determinados a partir de dados de transporte de massa obtidos a partir de cinéticas da degradação do CAP em função da vazão. No reator composto de DSA® observou-se um regime de fluxo laminar a baixo de Re = 2000 e um regime de fluxo turbulento acima desse valor, como esperado para um reator de placas paralelas. No reator de DDB, devido o aumento da área da secção transversal do compartimento entre eletrodos, há uma elevação de turbulência da face do anodo, impedindo a formação de um regime de fluxo laminar bem definido. Utilizando um efluente real contendo fenóis e derivados, foram aplicadas valores apropriados de densidade de corrente (Jap) para aumento dos valores de eficiência de corrente e diminuição dos índices de consumo energético. Aplicando-se um perfil exponencial de Jap (t) obteve-se um rendimento de corrente médio de 95 % e um consumo de 23,5 kWh por kg de O2. Com isso foi possível propor um método de operação de reatores de DDB para elevação dos índices de eficiência. De modo geral, os anodos de Ti/70TiO2-30RuO2 e de DDB ótimos desempenhos para a eletroxidação de cloranfenicol (CAP) e outros compostos orgânicos e para redução da DQO e do COT / Abstract: Electrochemical oxidation was used as a method for organic pollutant degradation in aqueous media. In the technique was used in solutions containing chloramphenicol (CAP) and phenolic compounds. A commercial DSA® type anode, of composition 70TiO2-30RuO2, and a boron-doped diamond anode (BDD) were used. Each anode was mounted in a filter-press type reactor connected to a recirculating flow system with 3 L of capacity. Initially, voltammetric studies were carried out with electrochemical reactors operating in hydrodynamic mode. On the DSA® type anode O2 evolution reaction was observed after 1 V vs. SCE and the current densities for O2 evolution decreased when chloramphenicol was present in solution. On stainless steel cathode, before H2 evolution, reduction of NO2 group to HO-NH- group was observed for CAP molecule, at pH = 5. On DDB, the anode was passived with an organic film at potentials from 0.6 V. Current responses on DDB anode were restored after anodic treatments within O2 evolution range of potentials. On BDD, O2 evolution took place after 2.2 V vs SCE. Galvanostatic experiments were carried out within the range of potentials for O2 evolution. Pseudo-first order kinetics were observed for CAP concentration decay on the DSA® anode, when current densities (Jap) were ranged from 50 to 180 mA cm-2, and from 10 to 30 mA cm-2 on DDB anode. Chemical oxygen demand (COD) and total organic carbon (TOC) showed linear concentration decays when the oxidation reactions were controlled by charge transfer process and it showed exponential decays when these reactions were controlled by mass transfer process. H2O2 production on DDB anode was investigated as function of Jap. Dimensionless numbers and their mass transfer figures of merit were studied from mass transport data of CAP decays as function of several flow rates. In the reactor composed by DSA® anode, a laminar flow was observed below Reynolds (Re) equal 2000 and a turbulent flow was observed above this value. In the BDD reactor, the transition between laminar and turbulent flow was not observed. Using a real effluent composed by phenols and derivates, appropriate values of Jap was applied on DDB reactor to increase the anodic efficiency and to reduce the energy consumption per kg of O2. Applying an exponential profile of Jap in galvanostatic experiments, an anodic efficiency of 95% was reached, corresponding to an energy consumption of 23,5 kWh per kg of O2. From these results an operation method of BDD reactors arose in order to increase the performance of this electrochemical device. Good performances were observed when DSA® and BDD anodes were used in electrochemical oxidation of chloramphenicol and other organic pollutants, especially in BDD case / Doutorado / Materiais e Processos de Fabricação / Doutor em Engenharia Mecânica
67

Capturing JUnit Behavior into Static Programs : Static Testing Framework

Siddiqui, Asher January 2010 (has links)
<p>In this research paper, it evaluates the benefits achievable from static testing framework by analyzing and transforming the <em>JUnit3.8 </em>source code and static execution of transformed code. Static structure enables us to analyze the code statically during creation and execution of test cases. The concept of research is by now well established in static analysis and testing development. The research approach is also increasingly affecting the static testing process and such research oriented work has proved particularly valuable for those of us who want to understand the reflective behavior of <em>JUnit3.8 Framework</em>.</p><p><em> JUnit3.8 Framework</em> uses <em>Java Reflection API</em> to invoke core functionality (test cases creation and execution) dynamically. However, <em>Java Reflection API</em> allows developers to access and modify structure and behavior of a program.  Reflection provides flexible solution for creating test cases and controlling the execution of test cases. Java reflection helps to encapsulate test cases in a single object representing the test suite. It also helps to associate each test method with a test object. Where reflection is a powerful tool to perform potential operations, on the other hand, it limits static analysis. Static analysis tools often cannot work effectively with reflection.</p><p>In order to avoid the reflection, <em>Static Testing Framework</em> provides a static platform to analyze the <em>JUnit3.8</em> source code and transform it into non-reflective version that emulates the dynamic behavior of <em>JUnit3.8</em>. The transformed source code has possible leverage to replace reflection with static code and does same things in an execution environment of <em>Static Testing Framework</em> that reflection does in <em>JUnit3.8</em>. More besides, the transformed code also enables execution environment of <em>Static Testing Framework</em> to run test methods statically. In order to measure the degree of efficiency, the implemented tool is evaluated. The evaluation of <em>Static Testing Framework</em> draws results for different Java projects and these statistical data is compared with <em>JUnit3.8</em> results to measure the effectiveness of <em>Static Testing Framework</em>. As a result of evaluation, <em>STF</em> can be used for static creation and execution of test cases up to <em>JUnit3.8</em> where test cases are not creating within a test class and where real definition of constructors is not required. These problems can be dealt as future work by introducing a middle layer to execute test fixtures for each test method and by generating test classes as per real definition of constructors.</p>
68

Cytochrome C biosensor for the determination of trace level arsenic and cyanide compounds

Fuku, Xolile Godfrey January 2011 (has links)
In this work, an electrochemical method based on a cyt c biosensor has been developed, for the detection of selected arsenic and cyanide compounds. Boron Doped Diamond (BDD) electrode was used as a transducer, onto which cyt c was immobilised and used for direct determination of Prussian blue, potassium cyanide and arsenic trioxide by inhibition mechanism. The sensitivity as calculated from cyclic voltammetry (CV) and square wave voltammetry (SWV), for each analyte in phosphate buffer (pH= 7) was found to be (1.087- 4.488 ×10-9 M) and the detection limits ranging from 0.0043- 9.1 μM. These values represent a big improvement over the current Environmental Protection Agency (EPA) and World Health Organisation (WHO) guidelines.
69

Cytochrome C biosensor for the determination of trace level arsenic and cyanide compounds

Fuku, Xolile Godfrey January 2011 (has links)
In this work, an electrochemical method based on a cyt c biosensor has been developed, for the detection of selected arsenic and cyanide compounds. Boron Doped Diamond (BDD) electrode was used as a transducer, onto which cyt c was immobilised and used for direct determination of Prussian blue, potassium cyanide and arsenic trioxide by inhibition mechanism. The sensitivity as calculated from cyclic voltammetry (CV) and square wave voltammetry (SWV), for each analyte in phosphate buffer (pH= 7) was found to be (1.087- 4.488 ×10-9 M) and the detection limits ranging from 0.0043- 9.1 μM. These values represent a big improvement over the current Environmental Protection Agency (EPA) and World Health Organisation (WHO) guidelines.
70

Cytochrome C biosensor for the determination of trace level arsenic and cyanide compounds

Fuku, Xolile Godfrey January 2011 (has links)
Magister Scientiae - MSc / In this work, an electrochemical method based on a cyt c biosensor has been developed, for the detection of selected arsenic and cyanide compounds. Boron Doped Diamond (BDD) electrode was used as a transducer, onto which cyt c was immobilised and used for direct determination of Prussian blue, potassium cyanide and arsenic trioxide by inhibition mechanism. The sensitivity as calculated from cyclic voltammetry (CV) and square wave voltammetry (SWV), for each analyte in phosphate buffer (pH= 7) was found to be (1.087- 4.488 ×10-9 M) and the detection limits ranging from 0.0043- 9.1 μM. These values represent a big improvement over the current Environmental Protection Agency (EPA) and World Health Organisation (WHO) guidelines. / South Africa

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