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Bigler, Matthias. "Hochauflösende Spurenstoffmessungen an polaren Eisbohrkernen : glazio-chemische und klimatische Prozessstudien /." [S.l.] : [s.n.], 2004. http://www.zb.unibe.ch/download/eldiss/04bigler_m.pdf.
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Climent-Gil, Emilio. "Abordando la complejidad. Vulnerabilidad y riesgo en la gestión de impactos sociales de las intervenciones sobre el medio." Doctoral thesis, Universidad de Alicante, 2020. http://hdl.handle.net/10045/113527.
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El problema de investigación que sustenta esta tesis por compendio de publicaciones gravita en la idea de que el influjo del enfoque tecnocrático y positivista dominante en el ejercicio de las EIA y EIS actuales – y que la perspectiva constructivista no ha logrado resolver-, provoca una serie de profundas carencias en la gestión social de las intervenciones planificadas como planteamiento. A partir del establecimiento de las dificultades subyacentes al enfoque tecnocrático como problema de investigación, esta subyacentes al enfoque tecnocrático como problema de investigación, esta tesis trata de afrontar desde la reflexividad sociológica los siguientes objetivos: 1.-Realizar un análisis crítico de la aproximación a la dimensión social del enfoque dominante de las EIS y EIA de las intervenciones sobre el medio desde una perspectiva paradigmática (axiología, ontología, epistemología y metodología). Concretamente aspira a: 2.- Establecer un diagnóstico de las consecuencias que posee la realización de los procesos de evaluación de las intervenciones desde el enfoque tecnocrático y positivista en relación con el tratamiento a través del análisis crítico de la aproximación a la dimensión social realizada desde el enfoque tecnocrático de la evaluación de impacto. 3.-Resolver las limitaciones detectadas mediante el desarrollo de propuestas teórico-conceptuales y metodológicas en el marco de varios casos de estudio. Específicamente pretender ahondar en las causas profundas generadoras de la desigual distribución de los riesgos e impactos entre los grupos humanos afectados a través de la introducción sistemática del enfoque de la vulnerabilidad social EIS. Asimismo, la introducción de este enfoque perseguirá proporcionar elementos conceptuales y metodológicos que faciliten la integración de la dialéctica entre procesos estructurales y capacidad de agencia en el análisis de impacto. Articular una propuesta metodológica que permita el análisis de las complejas relaciones de casualidad e interdependencias entre las redes sociales, económicas y ambientales desde el enfoque holístico y sistémico. Desarrollar, desde el marco de la transdisciplinariedad, una propuesta metodológica que posibilite la adecuada integración de la dimensión social de los procesos de evaluación.
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Yoshikawa, Daniel Sierra. "Efeito de tratamentos de modificação da superfície na resistência à corrsão do alumínio 1050." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-16062011-142133/.
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Neste trabalho foi investigado o efeito de vários tratamentos para modificação da superfície na resistência à corrosão do alumínio AA1050 com o objetivo de identificar um potencial substituto ao tratamento de cromatização. Os tratamentos adotados consistiram inicialmente de polimento da superfície até acabamento 1 m, seguido por uma etapa comercial. Este tratamento foi utilizado como preparação preliminar da superfície, anterior aos demais tratamentos testados. Amostras com o tratamento preliminar foram submetidas a diferentes tratamentos de modificação da superfície, especificamente, imersão em solução com moléculas auto-organizáveis (SAM) à base de difosfonato, imersão em água fervente para acelerar o crescimento de óxido-hidróxido de alumínio; uma combinação destes dois últimos tratamentos e cromatização em solução à base de cromo hexavalente. O comportamento de corrosão do alumínio AA1050 submetido aos diferentes tipos de tratamentos foi investigado por ensaios eletroquímicos como: medidas de potencial a circuito aberto em função do tempo de imersão, espectroscopia de impedância eletroquímica e ensaios de polarização potenciodinâmica. Utilizou-se solução de 0,5 M de Na2SO4 como meio corrosivo, tamponada a pH = 4,0. Microscopia eletrônica de varredura e análises semi-quantitativas de espectroscopia de energia dispersiva também foram utilizadas como medidas complementares nessa investigação. Observou-se que o tratamento com moléculas auto-organizáveis não se mostrou eficiente para proteção à corrosão para longos períodos de tempo em comparação aos demais tratamentos. A proteção fornecida pelos tratamentos, SAM e em solução a base de cromo hexavalente foi inferior à esperada. A etapa de boemitização ou crescimento acelerado de óxido-hidróxido de alumínio em água fervente se mostrou uma etapa essencial para aumento do desempenho frente à corrosão do alumínio AA1050. Os resultados obtidos para amostras submetidas ao tratamento de aceleração do crescimento de óxi-hidróxido seguido por imersão em solução com moléculas auto-organizáveis proporcionou uma melhora significativa na resistência à corrosão da superfície comparada aos demais tratamentos.The aim of this work is to investigate the effect of various treatments for surface modification on the corrosion resistance of the aluminum AA1050. All the samples were firstly exposed to a preliminary surface treatment that consisted of surface polishing, up to a finishing of 1 m, succeeded by degreasing in two alkaline solutions and finally deoxidizing in an acid solution. This treatment was used as a preliminary surface preparation and adopted as a reference for comparison with the others. After this treatment, samples were exposed to various treatments for surface modification, specifically, immersion for 3 hours in a solution with self assembling molecules based on diphosphonates (SAM), immersion in boiling water for 20 minutes to promote bohemite growth (bohemitization); a combination of these two last treatments (bohemitization+SAM) and passivation in an hexavalent chromium solution. The objective was to investigate the potential of the tested treatments to replace the ones based on hexavalent chromium that generates toxic residues. The corrosion behavior of AA1050 aluminum samples with the various surface treatments was investigated by electrochemical methods such as: open circuit potential measurements, electrochemical impedance spectroscopy and potentiodynamic polarization curves. The electrolyte used was a 0.5 mol L-1 Na2SO4 solution, buffered to pH = 4.0. Surface characterization techniques, such as scanning electron microscopy and energy dispersive spectroscopy were also used in this investigation. The results showed that the treatment with self assembling molecules was not effective to protect the AA1050 aluminum for long periods of exposure to the electrolyte comparatively to the other surface treatments tested. The effect of SAM treatment or passivation with hexavalent chromium solution on the AA1050 aluminum corrosion resistance was unexpected. The bohemitization treatment that consisted of favoring oxide-hydroxide growth by immersion in boiling water increased the corrosion resistance of the AA1050 aluminum, but the highest corrosion resistance was associated to the treatment that combined bohemitization with SAM treatment.
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Silva, Marco Antonio Oliveira da. "Estudos eletroquímicos de eletrólise a membrana polimérica para produção de hidrogênio." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-24082011-140854/.
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O uso do hidrogênio produzido pela água como vetor energético pode ser uma das soluções encontradas para evitar emissões de poluentes por ser uma energia limpa e renovável. Produzir o hidrogênio por intermédio de uma célula eletrolítica a membrana trocadora de prótons (PEMEC) é uma alternativa vantajosa, pois a forma sólida da membrana garante uma densidade de corrente elétrica maior comparada à eletrólise alcalina convencional, além de outras vantagens, como por exemplo, a relativa facilidade para manutenção. Os estudos presentes neste trabalho partiram da configuração de uma célula a combustível a membrana trocadora de prótons (PEMFC), entretanto, os dois tipos de células necessitam de materiais e catalisadores diferentes. Testes revelaram que placas bipolares de grafite da PEMEC não podem ser usadas, tampouco as de grafite cobertas com níquel devido à forte corrosão ocorrida na região anódica. A eletrólise por uma PEMEC é possível, no entanto, a escolha de materiais para a região anódica define a confiabilidade do método. Os aços inoxidáveis da série 3XX apresentaram os melhores resultados com níveis comerciais de produção de 75 a 85 mL.cm-2.min-1 de H2 em temperatura ambiente, com potencial de -1,9 V. Fizeram-se experimentos em PEMEC de aço AISI 310 que mostraram bom desempenho, mas ocorrendo corrosões e inviabilizando a continuidade do processo após 6h de operação. Análise por espectroscopia de impedância eletroquímica (EIE) na PEMEC desse aço foi feita para se estudar o aumento resistivo dos componentes da célula ao longo de uma sequência de eventos em um processo corrosivo do ânodo.The use of hydrogen produced by water as energy vector can be one of the solutions to prevent emissions of pollutants because it is a clean and renewable energy. To produce hydrogen through a proton exchange membrane electrolytic cell (PEMEC) is an advantageous alternative, because the membrane as a solid structure ensures a higher electrical current density compared to conventional alkaline electrolysis, among other advantages, such as a relative ease of maintenance. The studies in this work started from the configuration of a proton exchange membrane fuel cell (PEMFC), however, both cell types require different materials and catalysts. Tests revealed that graphite bipolar plates cannot be used in PEMEC, either nickel coated graphite due to heavy corrosion in the anodic region. Electrolysis by a PEMEC is possible, however, the choice of materials for the anode region defines the reliability of the method. The 3XX series stainless steel showed the best results with commercial production levels from 75 to 85 mL.cm-2.min-1 H2 at room temperature, with a potential of -1.9 V. Experiments were made in PEMEC steel AISI 310 which showed good performance to produce H2, but as the corrosion occurred, the process become inadequate after 6 hours of operation. Analysis by electrochemical impedance spectroscopy (EIS) in this PEMEC with bipolar steel plates was made to study the increase of the cell components resistances along a sequence of events in a process of anode corrosion.
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Ūselytė, Gintarė. "Magnetroniniu plazminiu būdu suformuotų Mg - Al - Zr lydinių paviršiaus anodinio tirpimo tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080924_222847-13165.
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Darbe tiriamas magnetroniniu plazminiu būdu suformuotų Mg-Al-Zr lydinių anodinis tirpimas, bei antikorozinės savybės. Magnetroniniu plazminiu būdu buvo suformuotos dangos su skirtingu cirkonio kiekiu (t.y. 95%, 90,4%, 76,2%, 71% ir 67%). Dangos formuojamos ant stiklo paviršiaus. Voltamperiniais ir elektrocheminio impedanso metodais ištirtas Mg-Al-Zr lydinių anodinis atsparumas ir korozinė elgsena 0.1 M (NH4)3BO3 + 0.1 M NaCl tirpale, kurio pH 8,5. MP lydinių korozinis atsparumas didėja, didinant Zr koncentraciją lydinyje. Taip pat lydiniai, kuriuose didesnė Mg koncentracija, bet mažesnė Zr aktyviai anodiškai tirpsta. Atominės jėgos mikroskopo metodu (AJM) nustatyta lydinių morfologija, dangos su didesne Zr koncentracija charakterizuojamos mažesniais kristalitų dydžiais. Aptartos MP metodo pritaikymo galimybės.The goal of this work was to study anodic dissolution and anticorrosion properties of Mg-Al-Zr alloys formed by magnetron sputtering. Magnetron sputtering technique was applied to deposit Mg-Al-Zr alloys with different amount of Zr, on glass substrates. Anodic dissolution and anticorrosive stability of the sputtered alloys were studied by voltammetric and electrochemical impedance spectroscopy methods in 0.1 M (NH4)3BO3 + 0.1 M NaCl solution (pH 8,5). EIS and voltammetric measurements indicated a lesser anodic dissolution and a superior anticorrosive resistance in Mg-Al-Zr alloys with higher Zr concentration. Atomic force microscopy demonstrated (AFM) that by increasing amount of Zr in sputtered samples the grain size decrease.
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Bieliauskaitė, Rita. "Magnetroniniu plazminiu būdu suformuotų Mg-Al-Zr lydinių puslaidininkinių savybių tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080924_175137-94085.
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Darbe tiriamos magnetroniniu plazminiu (MP) būdu suformuotų Mg – Al – Zr lydinių morfologinės, korozinės ir puslaidininkinės savybės. Magnetroninio plazminio dulkinimo metodu buvo suformuotos 5Mg-Al-95Zr, 33Mg-Al-67Zr, 29Mg-Al-71Zr, 24Mg-Al-76Zr, 8Mg-Al-90Zr dangos ant stiklo paviršiaus. Atominės jėgos mikroskopo (AJM) metodu nustatyta, kad magnetroniniu plazminiu būdu suformuotos Mg – Al – Zr lydinių dangos charakterizuojamos mažesniais kristalitų dydžiais ir tolygesne mikrostruktūra. Fotoelektrocheminiais ir elektrocheminio impedanso spektroskopijos metodais ištirta lydinių korozinė elgsena 0,1 M (NH4)3BO3 + 0,1 M NaCl ( pH = 8,5) tirpale. Mott – Shottky analizės metodu nustatytas puslaidininkinių paviršiaus sluoksnių laidumo pobūdis: 5Mg-Al-95Zr, 33Mg-Al-67Zr, 29Mg-Al-71Zr, 24Mg-Al-76Zr, 8Mg-Al-90Zr dangų atveju jis donorinis (n – tipo). Aptartos Mott – Shottky metodo taikymo magnetroninėms dangoms tirti galimybės.The aim of present work was to study corrosion properties of magnetron sputtered Mg – Al – Zr alloys and characterise semiconductor properties of the surface layers developed during corrosion. Atomic force microscopy (AFM) demonstrated, that sputtered alloys had a smaller grain size and a smoother surface. Fotocorrosion and electrochemical behaviour of tha alloys was studied in 0,1 M (NH4)3BO3 + 0,1 M NaCl ( pH = 8,5) solution. The Mott – Schottky plots of 5Mg-Al-95Zr, 33Mg-Al-67Zr, 29Mg-Al-71Zr, 24Mg-Al-76Zr, 8Mg-Al-90Zr electrodes showed a linear relationship between modified capacitance (C-2) on applied potential. It was concluded n – type semiconductivity for the layers on 5Mg-Al-95Zr, 33Mg-Al-67Zr, 29Mg-Al-71Zr, 24Mg-Al-76Zr, 8Mg-Al-90Zr alloys.
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Yusoff, Mohd Azam 1959. "EIS implementation in PETRONAS." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9187.
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Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2000.Also available online on DSpace at MIT.
Includes bibliographical references (leaves 106-107).
The thesis focuses on the Implementation of Executive Information system (EIS). The thesis will discuss the approaches of implementing EIS, what are organizational barriers need to be overcome, and what are the objectives for the EIS implementation. The key component of EIS is the performance measures. The approach for development of the performance measures and how they are used in EIS for performance management will also be discussed. The thesis will also focuses specifically on implementation of EIS in PETRONAS and the results of the implementation. Survey results indicates that PETONAS is experiencing some issues that need to be addressed. These include issues of the system performance and more critically the doubt that some of the managers have on the usefulness of the performance measures developed and the usefulness of the EIS in general.
by Mohd Azam Yusoff.
M.B.A.
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Dumm, Melanie. "Optimierte Tribopaarung Stahl - Eis, dargestellt an einer Bobkufe." Aachen Shaker, 2008. http://d-nb.info/989941817/04.
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Munno, Carolina Milanetto. "Análise do monitoramento pós estudo de impacto ambiental no Estado de São Paulo." Universidade Federal de São Carlos, 2005. https://repositorio.ufscar.br/handle/ufscar/4404.
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Previous issue date: 2005-10-26This work intented to realize a study about the situation of process of Environmental Impact Assessment (EIA) in São Paulo State, with emphasis in the monitoring pos-EIS (Environmental Impact Statment) phase, that it is essencial for the efficiency and efficacy of EIA. The purpose was to evaluate the frequency that the monitoring is realized, which are the methods used, what the efficiency, the negative points and the difficults to execution of this system. For that, it was realized a bibliography revision about national and internacional practices of EIA, with research at libraries of Secretaria de Meio Ambiente do Estado de São Paulo (SMA), Companhia Estadual de Saneamento Ambiental (CETESB), Departamento de Avaliação de Impacto Ambiental (DAIA) and USP, and researches on data base. It were made interviews with technicals directors of DAIA/SMA and was also elaborated a questioner, that approach some points of EIA practices in São Paulo State. This questioner was sent to professionals of area. The results evidenced that despite of monitoring pos-EIS is very impotant in the context of EIA, it is not executed in the most of the cases. Many failures are pointed out in the process, which results in the non aplication of monitoring pos-EIS. The lack of engagement with the environmental quality and the sustainability, the lack of structure in the environmental agencies, the bureaucratic and consequent slowness of the process, the little participation of community, the difficulty in getting material about the topic, and others are some of factors mentioned. If the procedure were not improved, for assure the accomplishment of terms and commitments defined, as well as the learning with mistakes and the rights of each case, a powerfull instrument of Environmental Policy would be discredited and turn on in one of numerous bureaucratic obstacles that difficult the access on natural resourses of the country, but are not efficient to assure that the improvement happens in benefit of society.
Este trabalho teve como objetivo realizar um estudo da situação do processo de Avaliação de Impacto Ambiental (AIA) no estado de São Paulo, enfatizando a fase de monitoramento pós-Estudo de Impacto Ambiental (EIA), que é essencial para a eficiência e eficácia da AIA. Pretendeu-se avaliar com que freqüência o monitoramento é realizado, quais os métodos utilizados para sua realização, qual sua eficiência, seus pontos falhos e quais as dificuldades de operacionalização deste sistema. Para tanto, foi realizada uma revisão bibliográfica sobre práticas nacionais e internacionais de AIA, com consultas às bibliotecas da Secretaria de Meio Ambiente (SMA), Companhia Estadual de Tecnologia de Saneamento Ambiental (CETESB), Departamento de Avaliação de Impacto Ambiental (DAIA) e da USP e pesquisas em banco de dados. Foram feitas entrevistas com diretores técnicos do DAIA/SMA e também foi elaborado um questionário, que aborda alguns pontos de práticas de AIA no Estado de São Paulo. Este questionário foi enviado para profissionais da área. Como resultado, foi constatado que, apesar de muito importante no contexto da AIA, o monitoramento pós-EIA não é praticado na maioria dos casos. Muitas são as falhas apontadas no processo, que acabam culminando na não aplicação do monitoramento pós-EIA. A falta de comprometimento com a qualidade ambiental e a sustentabilidade, a falta de estrutura dos órgãos ambientais, a burocratização e conseqüente lentidão do processo, a baixa participação da sociedade, a dificuldade em se conseguir material sobre o assunto, entre outros, são alguns dos fatores mencionados. Se os procedimentos não forem aperfeiçoados, de modo a garantir o cumprimento dos termos e compromissos definidos, bem como o aprendizado com os erros e acertos de cada caso, um poderoso instrumento de política ambiental poderá ficar desacreditado e converter-se em apenas mais um dos já numerosos entraves burocráticos que dificultam o acesso aos recursos naturais do país, mas não são eficazes para assegurar que seu aproveitamento se dê em benefício da sociedade.
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Fránková, Hana. "Ověření technologie BioSealing metodou EIS." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265705.
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Diploma thesis is dealing with recognition of Biosealing technology using electrical impedance spektrometry method. BioSealing is an innovative method of soil body reconstruction, which uses stimulation of soil bacterial activity to seal the leakage. The method was developed in the Netherlands and it was used in conditions of the Czech Republic in years 2015 and 2016 on the Hornice water work. This earth dam was monitored by electrical impedance spectrometry by apparatus with device Z-meter IV in this period and the data are processed and assessed in this diploma thesis.
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Cruz-Manzo, Samuel. "Electrochemical mechanisms of the impedance spectrum in polymer electrolyte fuel cells." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/12316.
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Electrochemical impedance spectroscopy (EIS) is a powerful technique that can be applied in-situ to deconvolute the various loss mechanisms in the polymer electrolyte fuel cell (PEFC) that occur at different rates. The frequency response of a PEFC that results from EIS is in essence characterised by energy dissipating and energy storing elements of the cell. It can be represented by an equivalent circuit that is composed of resistors and capacitors respectively. By understanding the arrangement and magnitude of the electrical components in the equivalent electrical circuit, it is possible to generate a deeper understanding of how and where the electrical energy that is generated due to the redox reaction is being dissipated and retained within the real physical system. Although the use of equivalent circuits is often an adequate approach, some electrochemical processes are not adequately described by electrical components. In which case, it is necessary to adopt a more rigorous approach of describing processes through the use of differential equations to describe the physics of the electrochemical system at the frequency domain. Studies in the literature have attempted to construct mathematical models to describe the impedance response of the cathode catalyst layer (CCL) based on conservation equations describing the electrochemical and diffusion processes. However this has resulted in a complicated mathematical analysis which in turn results in complicated solutions. The resulting equations cannot be easily validated against real-world EIS measurements and only analytical results have been reported. In this thesis a mathematical model to describe the impedance response of the CCL has been developed. This model is derived from fundamental electrochemical theory describing the physics of the CCL. The mathematical treatment is simplified by taking into account some considerations based on the EIS theory. The resulting model can be easily applied to real-world EIS measurements of PEFCs and presents parameters commonly known in the electrochemical area. The scientific contribution of this doctoral thesis is mainly divided in two sections: Modelling and Application. The first step of the modelling section develops an equation describing charge conservation in the CCL and together with Ohm s Law equation accounting for ionic conduction, predicts the impedance response of the CCL at low currents. The second step includes the change of oxygen concentration during the oxygen reduction reaction (ORR) into the equation accounting for CCL low current operation. The study of mass transport in the CCL is very complex; the literature has treated it with simplifications and approximations. The finite diffusion distance for oxygen to reach the reaction sites in the CCL forms a complicated network of multi-phase parallel and serial paths and can change in dimension at different operating conditions (flooding, drying). In the mathematical treatment of this doctoral thesis the finite diffusion distance and surface concentration of oxygen in the CCL are considered to be independent of the thickness of the CCL. EIS reflects only bulk measurements based on the total CCL thickness. Even though this results in an over-simplification for the oxygen diffusion in the total CCL, this approach simplifies the mathematical treatment to predict the impedance response of the CCL at high current operation, and as result it can be successfully validated against real-world EIS measurements. In the application section the model is applied with real-world EIS measurements of PEFCs. First the model is applied with EIS measurements presenting inductive effects at high frequencies. The model reveals mechanisms masked at high frequencies of the impedance spectrum by inductance effects. The results demonstrate that the practice of using the real part of the Nyquist plot where the imaginary part is equal to zero to quantify the ohmic resistance in PEFCs can be subject to an erroneous interpretation due to inductive effects at high frequencies. Secondly the model is applied to cathode impedance data obtained through a three-electrode configuration in the measurement system and gives an insight into the mechanisms represented at low frequencies of the impedance complex-plot. The model predicts that the low frequency semicircle in PEFC measurements is attributed to low equilibrium oxygen concentration in the CCL-gas diffusion layer (GDL) interface and low diffusivity of oxygen through the CCL. In addition the model is applied with simultaneous EIS measurements in an Open-Cathode PEFC stack. The factors that limit the performance of the PEFC stack are evaluated with simultaneous EIS measurements and the model. The results show that the change in impedance response of individual cells within the stack is attributed to oxygen limitations, degradation in membrane electrode assemblies (MEAs) and temperature distribution. This EIS knowledge enables an assessment of the state of health in operational fuel cell stacks. In the last section of the application section, the mathematical model translated in the time domain via reverse Laplace Transform predicts the current distribution through the CCL. This provides information to improve the performance of the CCL as well as determine the uptake of product water in the membrane. Finally the conclusions and future work are presented. This doctoral thesis has established a backbone understanding of how the electrochemical and diffusion mechanisms relate to the electrochemical impedance spectra of PEFCs. The goal of a future work is to develop this EIS knowledge into a real-time EIS system for non-intrusive diagnostics of degradation in operational PEFCs. This implies a modification of the model to consider oxygen transport through the CCL thickness as part of a multi-species mixture using mass transport theory including concentrated solution theory to fuel cell engineering.
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Souza, Iracy Conceição de. "Desejo ou renúncia: eis a questão." Universidade do Estado do Rio de Janeiro, 2009. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=1029.
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Nosso trabalho realiza a interpretação de três contos de Eça de Queirós Singularidade de uma rapariga loura (1874), No Moinho (1880), e José Matias (1897) visando abordar as diferentes relações entre sujeito e desejo. O campo teórico que norteia nossa leitura é a psicanálise, na vertente de seu criador e do projeto de retorno à obra freudiana empreendido por Jacques Lacan. Em cada conto, teremos uma história de amor, que coloca em cena o drama crucial do homem, dividido entre o desejo e o dever. A escolha pelo dever, implicando a renúncia do desejo, faz com que as personagens masculinas sejam massacradas pela imposição moral do superego e pelo medo das mulheres, as quais, como representantes do Outro sexo, permanecem enigmas sem decifração
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Lipinský, Vít. "Detekce infiltrace srážkové vody metodou EIS." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225719.
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The master‘s thesis deals with the detection of rainwater infiltration in soils using the method of electrical impedance spectrometry. Its aim is to assess the suitability of this method and equipment for measuring the role of water infiltration in soils.
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Samuel, Linoj Philip. "Immunogenicity, Subcellular Localization And Function Of the Eis Protein Of Mycobacterium tuberculosis." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1205%5F1%5Fm.pdf&type=application/pdf.
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Fredlén, Alexander. "Electrochemical impedance spectroscopy on NMC811 at varying temperature and state of charge." Thesis, KTH, Tillämpad elektrokemi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299455.
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I detta arbete har elektrokemisk impedansspektroskopi använts för att producera reproducerbara impedansdata för katodmaterialet NMC811. Data som skulle kunna användas som basen för parametrisering och konstruktionen av en fysik-baserad modell. Dessutom har effekten av laddningstillstånd, temperatur, och historian av cellen på impedansen undersökts. Baserat på resultaten av preliminära test så har experiment konstruerats i vilka katodens impedans i en NMC811//Grafit cell har undersökts vid olika temperaturer och laddningstillstånd, både efter laddning och urladdning av cellen. Reproducerbara resultat kunde erhållas och det visades hur laddningstillstånd och temperatur har en stor påverkan på impedansen. Tyvärr så kunde inget sägas om hystereseffekten på grund av dålig stabilitet i lågfrekvensområdet av impedansmätningarna.In this work, electrochemical impedance spectroscopy has been used to try and produce reproducible impedance data for the cathode material NMC811. Data that could serve as the basis of parameter extraction for the construction of a physics-based model. Furthermore, the effect of state of charge, temperature, and history of the cell on the impedance has been analysed. Based on the results of preliminary tests, an experimental cycle was constructed in which the cathode impedance of a NMC811//Graphite cell was measured at varying temperatures and state of charge, both following charge and discharge of the cell. Reproducible results were achieved, and it was shown how the state of charge and temperature of the cell had a major effect on the measured impedance. Unfortunately, no conclusions could be made about the history effect on impedance due to poor stability in the low frequency regions of the impedance measurements.
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Blidberg, Andreas. "Correlation between different impedancemeasurement methods for battery cells." Thesis, KTH, Skolan för kemivetenskap (CHE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-158475.
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Stricter regulations concerning emissions from road traffic and increasing fuel prices has lead to an interest in hybrid electric vehicles (HEVs). Today even manufacturers of heavy duty vehicles are introducing hybrid alternatives. Batteries are expensive and a complex part in HEVs, and ways of determining a battery’s capacity is a current research topic. When a battery is used it ages, i.e. the capacity decreases and the impedance rises. Since battery cost is high, it is important to be able to determine battery ageing properly. The focus of this master thesis has been on impedance measurement methods for Li-ion batteries. The work has been carried out in cooperation with Scania CV AB. When a battery is aged, the impedance increases. Monitoring ageing mechanisms could enable increased lifetime of the batteries through optimized usage in for example heavy duty hybrid vehicles. In this work, Hybrid Pulse Power Characterization (HPPC) has been compared with Electrochemical Impedance Spectroscopy (EIS). A major difference between these methods is that HPPC uses pulses of high direct current, whereas a small alternating current perturbation is used in EIS. EIS give information about different mechanisms influencing the battery impedance, e.g. internal resistance and charge transfer resistance, but requires expensive and complex laboratory equipment. HPPC gives less detailed information about the impedance, but is more similar to field applications for a vehicle. A literature survey showed that much research is conducted on in-situ impedance measurements of batteries. One example is the long-term demonstration of an Impedance Measurement Box (IMB), which is currently carried out at Idaho National Laboratory. The method uses a sum-of-sines signal consisting of octave harmonics for a fast impedance measurement with good precision. The results showed a good correlation with laboratory EIS measurements. The experimental part of this project suggest that a linear correlation exists between the discharge resistance from HPPC measurements and the sum of internal resistance and charge transfer resistance from EIS measurements. The linear fitting did not have very good R-squared value but a residual analysis showed that the residuals were randomly scattered around zero, indicating that a linear fitting is suitable. However, the precision of the results is too poor for the correlation to be useful in a real HEV application. Additional work to improve the linear fitting is recommended. Furthermore, it was showed that AC-components have to be used as a measurement signal in order to measure the complex impedance of a battery. A paired t-test was conducted in order to study if noise could be used as that signal for a battery under load. The impedance at 100 Hz was calculated, which corresponds to the second harmonic of the power grid. The difference between this impedance and the impedance measured at 100 Hz with EIS was statistically tested. For shorter times pans (in this case 20 milliseconds) after applying the DC pulse, using noise cannot be ruled out for measuring a battery’s impedance under load. But for longer time spans after applying the DC pulse (in this case 1.3 seconds), there was a significant difference between the two methods. Concentration gradients caused by mass transfer limitations could be causing this effect.
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Shabani-Nooshabadi, M., and Y. Jafari. "Electropolymerized Coatings of Poly (o-anisidine) and Poly (o-anisidine)-TiO2 Nanocompsite on Aluminum Alloy 3004 by using the Galvanostatic Method and Their Corrosion Protection Performance." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/34811.
Full textAbstract:
Poly (o-anisidine) (POA) and also poly (o-anisidine)-TiO2 (POA-TiO2) nanocomposite coatings on aluminum
alloy 3004 (AA3004) have been investigated by using the galvanostatic method. The electrosynthesized
coatings were characterized by FT-IR, SEM- EDX, SEM and AFM. The corrosion protection performances
of POA and also POA-TiO2 nanocomposite coatings were investigated in 3.5% NaCl solution by using
the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The
corrosion rate of nanocomposite coatings was found ∼900 times lower than bare AA3004. The results of
this study clearly ascertain that the POA-TiO2 nanocomposite has outstanding potential to protect the
AA3004 against corrosion.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34811
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Pidcock, Andrew. "Control of magnesium alloy corrosion through the use of engineered intermetallics." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9214.
Full textAbstract:
The low density and high relative strength of Mg alloys means they can offer engineering benefits over steels or Al alloys. However, the susceptibility of Mg alloys to corrosion has limited their exploitation and restricted their use to more benign environments. An Mg-Al intermetallic surface layer is a good candidate for a robust corrosion protection method. This work demonstrates their development by using a novel ionic liquid electroplating process to deposit Al on to Mg substrates that when heat treated diffuses to form discrete intermetallic layers. Examination of three Mg-Al-Zn alloys showed that the amount Mg-Al intermetallic phases in their microstructures was linked to the quantity of Al they contained. Subsequent self-corrosion measurements using electrochemical impedance spectroscopy demonstrated that their performance was connected to the amount of intermetallic present, and in particular the strength of the micro-galvanic couples generated between the anodic and cathodic phases. Measurements of the self-corrosion behaviour of manufactured samples of the Mg-Al intermetallics confirmed that they could provide significant improvements, but it was acknowledged that their noble nature compared to an Mg substrate would encourage galvanic corrosion if a surface layer was damaged. As such the galvanic activity of the Mg-Al-Zn alloys and Mg-Al intermetallics was compared against a pure Mg standard using zero resistance ammetry and the resistance box technique. Galvanic models of alloy self-corrosion and a damaged intermetallic surface layer were also used to assess the potential problem. These measurements demonstrated that the intermetallics could act as strong cathodes, but further discussion on the nature of the behaviour suggested means by which galvanic corrosion might self-limit or self-repair. The galvanic corrosion experiments also revealed how the combination of current flow and a solution saturated with Mg2+ ions could lead to the formation of a highly protective Mg(OH)2 film with promising characteristics.
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Wang, Peng. "Corrosion behaviour of zirconium alloys in high temperature aqueous environment by electrochemical impedance spectroscopy." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/corrosion-behaviour-of-zirconium-alloys-in-high-temperature-aqueous-environment-by-electrochemical-impedance-spectroscopy(e1bf6a9f-c8ca-45db-8e05-14ee723886d9).html.
Full textAbstract:
The corrosion behaviour of zirconium based alloys has been primarily investigated by electrochemical impedance spectroscopy (EIS). In-situ autoclave EIS experiments were performed in simulated primary coolant conditions in order to study the high temperature water corrosion of zirconium alloys in PWRs. In-situ impedance response of the corroding material was recorded throughout first kinetic transition. A physical model of the zirconium oxide was proposed in accordance with the microstructural observation' made by SEM analysis. Electrical properties of the oxide was evaluated with equivalent circuit model (ECM) which was constructed according to the physical oxide model. Evolution of various oxide parameters obtained from ECM was analysed in accordance with the microstructure observation made by SEM. A two layer structure consists of a outer porous oxide and an inner barrier oxide, was found to be the most accurate description for the autoclave formed oxide. Supporting evidence from the SEM cross-section and surface analysis of the oxide had shown cracks and pores that were linked and connected with the environment. This observation is also confirmed by the in-situ EIS measurement which has shown porous electrode behaviour throughout the course of oxidation. The porous oxide behaviour was also confirmed by the ex-situ soaking experiment on samples with incremental exposure time. Evolution of inner barrier layer oxide thickness was found to be correlated with kinetic transition which was determined from weight gain measurement. This indicated that barrier layer maybe the oxidation rate controlling layer and its thickness maybe reduced during transition. Thus, a thinner barrier layer would resulted in a rapid corrosion of zirconium alloys. Furthermore, maintaining the barrier layer thickness maybe the possible route to improve zirconium alloy corrosion resistance.
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Lemire, Colombe. "Fidélité et validité de contenu des nouveaux domaines du programme EIS Évaluation intervention suivi (EIS) : littératie et numératie." Thèse, Université du Québec à Trois-Rivières, 2013. http://depot-e.uqtr.ca/7312/1/030619132.pdf.
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Abdalah, Samira Lessa. "Currículo e didática da diferença : dançário de EIS AICE." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/184675.
Full textAbstract:
Esta escrita t ranscorre por linhas que t rabalham um currículo e uma didát ica da t radução. Esse ato de escrever alia-se à imagem poét ica para pensar deslocamentos dos sete elementos que const ituem os blocos de pensamento de um currículo (EIS) e de uma didát ica (AICE). A escrita vem do corpo do pensamento e da linguagem, que se violentam ao encont ro de pensar como criação, sob os conceitos filosóficos de Deleuze e da filosofia da diferença. Os significados das palavras t ranspassam o sent ido literal, ao serem usadas como imagens poét icas e t ranscriadas num Dançário de EIS AICE. Produz poét ica na tentat iva de pôr, em movimentos, textos das imagens eisaiceanas ao serem operacionalizados com materiais desenvolvidos no Projeto Escrileit uras: um modo de ler e escrever em meio à vida, Obeduc/CAPES/INEP (2011-2014) problemat izando a ação docente nos espaços t radutórios do currículo e da didát ica ao most rar suas experimentações em t rês blocos de escrita. De modo que as palavras movam-se por um devir dançante buscando um vazio de fala, de um autor e de uma escrileitura por vir. Propõem dispor, diante dos arquivos operatórios, diferentes formas de pensar sobre o bloco de pensamento de EIS AICE.This writ ing works with a curriculum and didact ics of the t ranslat ion. This act of writ ing join the poet ic image to think about displacement s of the seven element s that const itute the blocks of thought about a curriculum (EIS) and didact ics (AICE). The writ ing comes from the body of the thought and the language that they clash at t ime to think of creat ion, under the philosophical concept s of Deleuze and the philosophy of difference. The meanings of the words t ranscend the literal meaning, when they are get using as poet ic images and recreated in an Dancing of EIS AICE. I t produces poet ics in the at tempt to put , agoing, text s of the eisaiceanas images when they are operat ionalized with materials developed in the Escrileituras Project : um modo de ler e escrever em meio à vida, Obeduc / CAPES / INEP (2011-2014), problemat izing the teaching act ivity in spaces of the curriculum and didact ics by showing their experiment s in three writ ing blocks. So that the words move through a dancing becoming, seeking a void of speech, of an author and of a writ reading to come. The writ ing proposes to provide, before the operat ive archives, different ways of thinking about the block of thought of EIS AICE.
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Dias, Elen [UNESP]. "Falar ou não falar?: eis a questão." Universidade Estadual Paulista (UNESP), 2003. http://hdl.handle.net/11449/93898.
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Made available in DSpace on 2014-06-11T19:26:49Z (GMT). No. of bitstreams: 0
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dias_e_me_sjrp.pdf: 2019476 bytes, checksum: 1fe67d4117b0fee7e76c959096c6f4e8 (MD5)Esta dissertação tem por objetivo investigar as razões que levam o aluno participante de dois contextos de ensino-aprendizagem de língua estrangeira (C1 e C2) a não conseguir comunicar-se oralmente em sala de aula, apesar da tentativa de implementar a abordagem comunicativa pela professora, cuja prática de sala de aula se caracteriza pelo desenvolvimento de atividades interativas. Visa também buscar compreender até que ponto de que maneira a prática de sala de aula da professora-pesquisadora contribui ou prejudica o desenvolvimento da competência (proficiência) oral. Metodologicamente, este estudo foi desenvolvido como pesquisa-ação de natureza colaborativa, que se coloca entre os modelos qualitativo-interpretativistas de sala de aula como contexto de pesquisa de investigação aplicada (CAVALCANTI & MOITA LOPES, 1991), e nas discussões teóricas de métodos e técnicas de um ensino prático reflexivo e de formação de professores de línguas (WIDDOWSON, 1991; CELANI, 2003). Em outras palavras, um fazer reflexivo como forma de construção de conhecimento mais eficaz entre professorpesquisador, alunos, coordenadores, como formação continuada (FREIRE, 1997). O trabalho apresenta resultados que permitem identificar algumas concepções teóricas de ensino-aprendizagem. As crenças e a cultura de aprender e ensinar línguas (ALMEIDA FILHO, 1993; BARCELOS, 1999, 2000) revelaramse fatores intervenientes, capazes de afetar a receptividade do aprendiz à abordagem de ensino do professor e de revelar discrepâncias entre as expectativas do aluno e as do professor. Conseqüentemente, contribuem para ajudar na compreensão do problema e na elaboração de um plano de ação mais eficaz, proporcionando, desse modo maiores chances de sucesso de intervenção no processo pedagógico. Discute, finalmente, possíveis propostas geradoras de mudanças na educação de professores em formação...
This research study aims at investigating the reasons why students of two contexts of foreign language teaching (C1 and C2) are not able to communicate orally in the classroom in spite of the teacher s tentative of applying the communicative approach, based on interactive activities. Moreover, it intends to understand how the teacher educator-researcher s practice in the classroom may contribute to the development of the students oral competence (and proficiency). Methodologically developed as an action research (CAVALCANTI & MOITA LOPES, 1991) in a collaborative project, this study thinks over the classroom reality according to the theoretical discussions of reflective teaching and of the pre-service foreign language teacher s education (WIDDOWSON, 1991; CELANI, 2003). In other words, a reflective and scientific way of understanding teacher education in order to (re)build it up more effectively as a mutual process of continuous education involving the teacher educator-researcher, the students and the coordinators (FREIRE, 1997). This work presents results, which allow the identification of some theoretical conceptions about the learning-teaching process. The students and the teacher s beliefs about learning and language learning (ALMEIDA FILHO, 1993; BARCELOS, 1999, 2000) were revealed as intervening factors which affected the students receptiveness to the teacher s teaching approach and possible discrepancies between what student s expectations are and what the teacher expects from them. Consequently, it may help to understand the difficulties and to elaborate an effective syllabus, providing, as a result, better opportunities for intervention in the pedagogical process. It finally discusses possible proposals, which may provide changes in preservice teacher s education as well as options by revealing conceptions, which can impede the students communicative development...(Complete abstract, click electronic access below)
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Golfinopoulos, Theodore. "Oxygen reduction on platinum : an EIS study." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/46379.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Vita.
Includes bibliographical references (p. 197-200).
The oxygen reduction reaction (ORR) on platinum over yttria-stabilized zirconia (YSZ) is examined via electrochemical impedance spectroscopy (EIS) for oxygen partial pressures between 10-4 and 1 atm and at temperatures between 475 and 700°C. Use of photolithographic techniques in electrode fabrication renders a precise geometry of the Pt electrodes. Circular electrode design leads to cylindrical symmetry so that models may be applied exactly to the experimental geometry. Interpretation of EIS spectra is carried out by reducing and then extending existing models, and is consistent with the postulate that ORR is rate-limited jointly by two surface chemical processes, namely, sorption/dissociation of molecular O₂ into O[delta]- a over Pt, as well as surface diffusion. Further, the novel experimental design, in conjunction with streamlined analysis techniques, provides accurate surface characterization within the electrochemical environment and allows for a more transparent comparison to relevant literature data. An adsorption coverage isotherm is extracted, and the surface diffusion coefficient is obtained for a number of experimental conditions. Extracted diffusivities fell between 2 x 10-2 and 2 x 10-7 cm2/s, in agreement with literature values for the indicated temperature range.
by Theodore Golfinopoulos.
S.M.
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Shain, Rachel Maureen. "The preverb eis- and Koine Greek aktionsart." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1238085936.
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Fernandes, Maria Aparecida Castro. "Conhecer ou não conhecer eis a diferença." Florianópolis, SC, 2000. http://repositorio.ufsc.br/xmlui/handle/123456789/78725.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico.Made available in DSpace on 2012-10-17T18:21:41Z (GMT). No. of bitstreams: 1 175234.pdf: 557035 bytes, checksum: fc0f7467dd3aa5772b86e1ec2be20ac7 (MD5)
Este estudo é uma investigação acerca da questão cognitiva especifica da cidade de Campanha, inserida na Linha de Pesquisa Universidade e a Formação do Conhecimento Humano . Nele, há uma análise da aquisição do conhecimento realizada cotejando como prática idealizada pela população do município de Campanha, no Estado de Minas Gerais. O seu objetivo fundamental consiste em realizar um estudo comparativo entre um grupo da camada popular a que denominamos saber Tia Nastácia e o grupo dos acadêmicos da FAFI-SION a que denominamos de saber Dona Benta, abordando a aquisição do conhecimento, a questão da cognição a partir de suas relações com a tecnologia Pretende-se contribuir para um mais adequado redirecionamento na educação dos pesquisados, a partir de experiências vívidas e vividas pela pesquisadora e pelos sujeitos da pesquisa. A metodologia usada para este estudo se fundamenta em vários autores, sendo no primeiro momento utilizando um texto como instrumento de sondagem; ponto de partida para toda a pesquisa qualitativa. Para uma melhor organização e análise dos dados coletados, tornou-se como referência os discursos dos próprios sujeitos, evidenciando os empecilhos de ordem estrutural, cultural e social, para a operacionalização do ideal, a identificação que os sujeitos encontram entre o real e o ideal, e contradições entre o discurso prático e teórico. Em seguida, os discursos foram novamente organizados como constatações e contestações, separadas em categorias distintas que são SER, o homem SABER, o mundo e FAZER a sociedade na visão dos grupos pesquisados. Espera-se que este estudo venha contribuir para um redimensionamento cultural do município e também para repensar, refletir sobre a psicologia do desenvolvimento sintetizando a forma como as pessoas adquirem conhecimentos e dão significados a tudo que os cercam neste mundo globalizado.
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Dias, Elen. "Falar ou não falar? : eis a questão /." São José do Rio Preto : [s.n.], 2003. http://hdl.handle.net/11449/93898.
Full textAbstract:
Orientador: Douglas Altamiro ConsoloBanca: João Bosco Cabral dos Santos
Banca: Marilei Amadeu Sabino
Resumo: Esta dissertação tem por objetivo investigar as razões que levam o aluno participante de dois contextos de ensino-aprendizagem de língua estrangeira (C1 e C2) a não conseguir comunicar-se oralmente em sala de aula, apesar da tentativa de implementar a abordagem comunicativa pela professora, cuja prática de sala de aula se caracteriza pelo desenvolvimento de atividades interativas. Visa também buscar compreender até que ponto de que maneira a prática de sala de aula da professora-pesquisadora contribui ou prejudica o desenvolvimento da competência (proficiência) oral. Metodologicamente, este estudo foi desenvolvido como pesquisa-ação de natureza colaborativa, que se coloca entre os modelos qualitativo-interpretativistas de sala de aula como contexto de pesquisa de investigação aplicada (CAVALCANTI & MOITA LOPES, 1991), e nas discussões teóricas de métodos e técnicas de um ensino prático reflexivo e de formação de professores de línguas (WIDDOWSON, 1991; CELANI, 2003). Em outras palavras, um fazer reflexivo como forma de construção de conhecimento mais eficaz entre professorpesquisador, alunos, coordenadores, como formação continuada (FREIRE, 1997). O trabalho apresenta resultados que permitem identificar algumas concepções teóricas de ensino-aprendizagem. As crenças e a cultura de aprender e ensinar línguas (ALMEIDA FILHO, 1993; BARCELOS, 1999, 2000) revelaramse fatores intervenientes, capazes de afetar a receptividade do aprendiz à abordagem de ensino do professor e de revelar discrepâncias entre as expectativas do aluno e as do professor. Conseqüentemente, contribuem para ajudar na compreensão do problema e na elaboração de um plano de ação mais eficaz, proporcionando, desse modo maiores chances de sucesso de intervenção no processo pedagógico. Discute, finalmente, possíveis propostas geradoras de mudanças na educação de professores em formação...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This research study aims at investigating the reasons why students of two contexts of foreign language teaching (C1 and C2) are not able to communicate orally in the classroom in spite of the teachers tentative of applying the communicative approach, based on interactive activities. Moreover, it intends to understand how the teacher educator-researchers practice in the classroom may contribute to the development of the students oral competence (and proficiency). Methodologically developed as an action research (CAVALCANTI & MOITA LOPES, 1991) in a collaborative project, this study thinks over the classroom reality according to the theoretical discussions of reflective teaching and of the pre-service foreign language teachers education (WIDDOWSON, 1991; CELANI, 2003). In other words, a reflective and scientific way of understanding teacher education in order to (re)build it up more effectively as a mutual process of continuous education involving the teacher educator-researcher, the students and the coordinators (FREIRE, 1997). This work presents results, which allow the identification of some theoretical conceptions about the learning-teaching process. The students and the teachers beliefs about learning and language learning (ALMEIDA FILHO, 1993; BARCELOS, 1999, 2000) were revealed as intervening factors which affected the students receptiveness to the teachers teaching approach and possible discrepancies between what students expectations are and what the teacher expects from them. Consequently, it may help to understand the difficulties and to elaborate an effective syllabus, providing, as a result, better opportunities for intervention in the pedagogical process. It finally discusses possible proposals, which may provide changes in preservice teachers education as well as options by revealing conceptions, which can impede the students communicative development...(Complete abstract, click electronic access below)
Mestre
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Šandová, Iva. "Stanovení obsahu vody v zemině metodou EIS." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226153.
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This thesis deals with the measurement of water content in soil using electrical impedance spectrometry. The aim is to characterize and determine the conditions of applicability of this method and of measuring apparatus with device Z-meter III for instance for the application of the field measurements of earth dams.
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Buchanan, David Andrew. "The origin and meaning of EIS/AION phrases in the New Testament." Theological Research Exchange Network (TREN), 1988. http://www.tren.com.
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Roberts, Esteban Alberto. "Molecular characterization of the eis promoter of Mycobacterium tuberculosis and expression of eis in culture and during macrophage infection." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280794.
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Previous work in the laboratory of Dr. Richard Friedman identified the eis gene as capable of enhancing the survival of avirulent Mycobacterium smegmatis within U-937 macrophage-like cells. Studies were undertaken to identify the promoter for eis in both M. smegmatis and M. tuberculosis H37Ra. A 412 base pair region upstream of the eis coding sequence, as well as a DinR-like cis element, was necessary for the full expression of eis in both mycobacteria. To study the expression of eis further, a destabilized luciferase-based reporter system was constructed for fusion of the 412 base pair eis promoter. The expression of eis was monitored throughout culture growth of both M. smegmatis and M. tuberculosis H37Ra using this novel reporter and quantitative real-time PCR. In M. smegmatis, eis was induced upon transition from logarithmic to stationary phase as detected by both luciferase activity and real-time PCR. In M. tuberculosis H37Ra, expression from the eis promoter driven luciferase construct could not be detected, although real-time PCR showed that eis was constitutively expressed. Analysis of groEL2 expression by real-time PCR in comparison with phsp60 driven luciferase production showed that this novel luciferase system could also detect expression changes in M. tuberculosis H37Ra. The lack of luciferase expression from the eis promoter suggested that the utility of this system was dependent on the promoter. eis and groEL2 expression were then monitored in both mycobacteria during the infection of U-937 cells. In M. smegmatis, analysis of eis expression using luciferase suggested that eis was not induced during initial infection, but showed that eis is repressed between 3 h and 24 h of infection. Luciferase production from the eis promoter did not change upon the infection of macrophages with M. tuberculosis H37Ra, suggesting that the eis promoter construct was non-functional. Real-time PCR analysis of eis expression during infection of U-937 cells with M. tuberculosis H37Ra showed that eis is constitutively expressed during macrophage infection. A comparison of groEL2 expression and luciferase activity from phsp60 showed high variability in heat-shock expression and suggested that the luciferase system was not suitable for detecting groEL2 expression changes during macrophage infection.
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Zsigmond, András. "Testování prototypového zařízení využívající metodu elektrochemické impedanční spektroskopie (EIS)." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-400712.
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.Tato diplomová práce se zabývá elektrochemickými procesy v lítium-iontových bateriích. Pro charakterizaci různých elektrochemických procesů se používá metoda nazývaná elektrochemická impedanční spektroskopie (EIS). V prvních kapitolách jsou popsány různé typy baterií a jejich rozdíly. Práce také obsahuje popis experimentálního zařízení používaného pro EIS. Součástí práce je také porovnání experimentálního zařízení a zařízení od společnosti BioLogic Science Instruments.
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Arifin, Azizah. "Managing the benefits of executive information systems in the public service." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843021/.
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Although investment in IT is growing rapidly, a number of studies have shown that the full benefits of this technology are not realised. One explanation is that these benefits exist, but have not been correctly measured. The other explanation is that they have not been achieved because of lack of management attention. Experience and common sense supports the latter assumption. Hence, the aim of this research is to develop and to trial a method which assists in the realisation of the benefits of a particularly problematic technology, executive information systems (EIS).The proposed method introduces the concept of generic benefits models into previous research on IT benefits management. This construct improves existing methods of benefits management in three respects. First, it employs reuse of benefits models in order to speed their development. Secondly, it allows these methods to be employed at any stage of a project, not just at the outset, in order to extract benefits. Thirdly, it provides a conceptual object which serves as the focus of organisational learning. The major focus of the research is on the development of generic benefits models of EIS. This requires an understanding of the role which information plays in executive work and how EIS technology may affect the manner in which executives use information. Unfortunately, the literature on executive work does not make this clear. Moreover, it seems that there is no agreed definition of EIS. As a result, it is necessary to create different generic models for different theories of executive work and different forms of EIS. The methodological approach adopted is pragmatism, in particular the experimentalism proposed by John Dewey and implemented by Donald Schon. The justification for this is that the primary objective of the study is to demonstrate the utility of the proposed method rather than its ability to explain, predict, or provide insight. The study includes six experiments conducted within the office of the Malaysian Prime Minister. Different types of EIS, with different degrees of benefits already realised, and at different stages of development are the subjects of these experiments. The results largely affirm the proposed method, but they do suggest some refinement of the original benefits models. They also indicate simplification of the models is possible. In addition the executives who participated in these experiments favour the proposed method. However, the IS practitioners in the organisation are less enthusiastic. The study proposes a solution to this problem which includes both changes to organisational structure and to the education of IS practitioners. The research also produced a number of supplementary findings. It reaffirmed the findings of Mintzberg's study of executive work. It demonstrated once again that executives rarely use EIS directly and that they mostly depended on subordinates to access information. When executives do employ EIS themselves, they are more likely to use it to enhance their learning than to support decision-making.
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Barbaravičiūtė, Virginija. "Magnetroninių plazminių magnio lydinių elektrocheminis ir korozinis charakterizavimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060613_173636-54335.
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The aim of present work was to study corrosion properties of magnetron sputtered Mg–Al alloys and characterize semiconductor properties of the surface layers developed during corrosion. Atomic force microscopy (AFM) demonstrated that sputtered alloys had a smaller grain size and a smoother surface. Corrosion and electrochemical behaviour of the alloys was studied in 0,1M (NH4)3BO3 + 0,1M NaCl (pH = 8,4) solution. Sputtered films of Al-Mg and Al had a superior resistance to pitting corrosion when compared to cast counterparts. The corrosion resistance of sputtered samples increased with decrease in Mg content. The Mott – Schottky plots of Al-Mg and pure Al electrodes showed a linear relationship between modified capacitance (C-2) on applied potential. It was concluded n – type semiconductivity for the layers on Al and p – type for Al-Mg alloys.
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Gambina, Federico. "Corrosion Resistance Characterization of Coating Systems Used to Protect Aluminum Alloys Using Electrochemical Impedance Spectroscopy and Artificial Neural Networks." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1281361408.
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Sun, Xihe. "Novel carbon electrodes for zinc–bromine batteries." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/12844.
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Zinc-bromine batteries have long been considered one of the most suitable storage technologies due to their potential long life, deep discharge characteristics and potential low manufacturing cost, as well as very high theoretical specific energy density (~440 Wh/kg). However, there are still a number of challenges to their commercial success, including electrode lifetime, electrochemical efficiency and cost. The major purpose of this study is to investigate the property of both zinc and bromine electrodes in zinc bromine flow batteries, and to develop new materials for zinc bromine flow battery electrodes, suitable for utility scale use. Different carbon materials and high density polyethylene-carbon composites have been evaluated through physical and electrochemical methods. Calgon activated carbon, carbon cloth, multi-walled carbon nanotubes (MWCNTs), reduced graphene oxide (rGO) and cryogel carbon have been investigated as the electrocatalysts for the bromine/bromide redox couple reaction in the positive half-cell of the zinc bromine redox flow batteries. As for the zinc electrodes, high density polyethylene (HDPE)-carbon black (CB) and HDPE-multiwall carbon nanotubes (MWCNTs) composites have been studied with macroscopic and microscopic techniques. The MWCNTs shows the best performance of the five carbon candidates. The HDPE-CB composite electrode exhibits better zinc deposition than the HDPE-CNT composite electrode due to a lower nucleation overpotential and higher exchange current density. In addition, the interfacial structure of the electrode/electrolyte on the bromine electrode and zinc electrode in zinc bromine electrolyte has been illustrated for the first time using electrochemical impedance spectroscopy.
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Gahl, Cornelius. "Elektronentransfer- und Solvatisierungsdynamik in Eis adsorbiert auf Metalloberflächen." [S.l. : s.n.], 2004. http://www.diss.fu-berlin.de/2004/338/index.html.
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Fröhling, Anja. "Literarische Reisen ins Eis interkulturelle Kommunikation und Kulturkonflikt." Würzburg Königshausen und Neumann, 2003. http://deposit.ddb.de/cgi-bin/dokserv?id=2683509&prov=M&dok_var=1&dok_ext=htm.
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Scheller, Marita, Heiko Ewert, Andreas Groh, and Martin Horwath. "Wasser und Eis - Satellitendaten zur Bilanzierung von Massentransporten." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-170427.
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Renker, B. [Verfasser]. "Gitterdynamik von D₂O-Eis Ih / B. Renker." Karlsruhe : KIT-Bibliothek, 2009. http://d-nb.info/1186905158/34.
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Scheller, Marita, Heiko Ewert, Andreas Groh, and Martin Horwath. "Wasser und Eis - Satellitendaten zur Bilanzierung von Massentransporten." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A27695.
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Munz-Krines, Marion. "Expeditionen ins Eis historische Polarreisen in der Literatur." Frankfurt, M. Berlin Bern Bruxelles New York, NY Oxford Wien Lang, 2008. http://d-nb.info/990885712/04.
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Fröhling, Anja. "Literarische Reisen ins Eis : interkulturelle Kommunikation und Kulturkonflikt /." Würzburg : Königshausen und Neumann, 2005. http://catalogue.bnf.fr/ark:/12148/cb410521906.
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Hernández, Victor Ernesto Pérez. "Comportamento de corrosão de camadas isentas de cromo hexavalente e sem enxágue aplicadas sobre superfícies eletrozincadas produzidas em linhas contínuas." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-31122015-115301/.
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A preocupação com o desenvolvimento sustentável tem levado a indústria e os órgãos controladores do meio ambiente a reavaliarem o emprego em larga escala de procedimentos industriais que, embora eficientes, são prejudiciais à saúde humana e ao meio ambiente. Em concordância com estas novas tendências, as indústrias de tratamento de superfícies de metais e instituições de pesquisa têm empregado grandes esforços no sentido de encontrar substitutos eficientes para procedimentos de proteção contra a corrosão que contenham íons de cromo hexavalente, os quais são muito eficientes, mas apresentam o inconveniente de não serem ambientalmente corretos devido ao caráter cancerígeno e poluente do íon Cr(VI) já reconhecido por diversas agências de proteção ambiental. Com a finalidade de aumentar a proteção contra a corrosão, em linhas industriais contínuas de eletrogalvanização por eletrodeposição, as peças produzidas são protegidas por uma camada de passivação obtida em banho de conversão contendo sais de Cr(VI) e, na maioria dos casos, não passa pelo processo de enxágue após sua produção. Neste trabalho o comportamento de corrosão do aço eletrogalvanizado protegido com camadas de passivação obtidas a partir de banhos de conversão contendo sais de Cr(III) e Co(II) ou uma emulsão de um copolímero de etileno, sem enxágue, foi avaliado por técnicas eletroquímicas, especificamente, acompanhamento do potencial de circuito aberto, curvas de polarização potenciodinâmica anódicas e catódicas, e espectroscopia de impedância eletroquímica (EIS), em soluções com diferentes concentrações de NaCl. Adicionalmente foi avaliado o comportamento de corrosão por ensaios em câmara de névoa salina, realizados de acordo com a norma ASTM B117-11. Como referência, os resultados foram comparados com aqueles apresentados por amostras protegidas por camada de passivação produzida a partir de banho contendo íons de Cr(VI). Para melhor compreender a influência da microestrutura sobre o mecanismo de corrosão, as amostras foram caracterizadas por microscopia eletrônica de varredura antes e após imersão nos diferentes eletrólitos. A análise microestrutural foi complementada por ensaios de difração de raios-X. 7 Os resultados dos ensaios eletroquímicos realizados após tempos curtos de imersão mostraram melhor desempenho para as amostras protegidas com a camada de passivação produzida a partir de banho contendo íons Cr(VI). Entretanto os ensaios de EIS após tempos mais longos de imersão nos diferentes eletrólitos ensaio, bem como os ensaios de névoa, evidenciaram que as amostras protegidas com a camada passiva obtida a partir do banho contendo íons de Cr(III) e Co(II) podem apresentar desempenho semelhante àquelas protegidas com camada de conversão de Cr(VI). Para esta condição, a análise microestrutural e o ajuste dos diagramas de EIS com circuitos equivalentes indicaram um papel importante dos produtos de corrosão no comportamento anticorrosivo das amostras protegidas com a camada de passivação de Cr(III) e Co(II). Em nenhuma das condições estudadas as amostras protegidas com o copolímero de etileno apresentaram desempenhos comparáveis aos das outras duas camadas de passivação estudadas.Recent concerns with sustainable development have led industries and environment regulatory agencies to reassess the use at large scale of industrial procedures that, although efficient, are harmful to human health and the environment. In accordance with these new tendencies, surface treatment industries and research institutes have expended great efforts to find efficient substitutes for corrosion protection procedures that employ hexavalent chromium ions (Cr(VI)). They are very effective but have the drawback of not being environmentally friendly due to the carcinogenic and pollutant properties of Cr(VI) ions, already recognized by several environmental protection agencies. Aiming to increase the corrosion protection, in industrial continuous lines of galvanizing by electroplating, the parts produced are protected with a passivation layer obtained from a conversion bath containing Cr(VI). These parts are not rinsed after the final production step. In this work the corrosion behavior of electroplated galvanized steel protected with passivation layers from conversion baths containing Cr(III) and Co(II) ions or an ethylene copolymer emulsion was evaluated by means of electrochemical techniques, specifically, open circuit potential measurements, anodic and cathodic potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The tests were performed in sodium chloride solutions of different concentrations. Additionally, the corrosion behavior was evaluated by salt spray tests performed according the ASTM B117-11 standard. For reference, the results were compared with those presented by samples protected by passivation layers produced from conversion baths containing Cr (VI) ions. Aiming to better understand the influence of microstructure on the corrosion mechanism, the samples were characterized by scanning electron microscopy before and after immersion in the different electrolytes. Microstructure analysis was complemented by X-ray diffraction. The results of electrochemical tests performed after short immersion times showed better corrosion performance for samples protected with the passivation layer produced from conversion baths containing Cr(VI) ions. However, the EIS tests performed after longer immersion times in the different electrolytes, as well as the 9 salt spray tests, showed that samples protected with the passive layer obtained from the bath containing Cr (III) and Co (II) ions may present similar performance to those protected with the Cr (VI) conversion layer. The microstructural analysis and fitting of the EIS diagrams with equivalent circuits indicated an important role of corrosion products in the anti-corrosive performance of the samples protected with the passivation layer of Cr (III) and Co (II). In the studied conditions, the samples protected with the ethylene copolymer did not showed comparable performance to the other two passivation layers investigated in the present study.
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Ferrari, Jean Vicente. "Estudo da corrosão localizada da liga de alumínio 7475-T761 por espectroscopia de impedância eletroquímica global e local em meio de sulfato de sódio." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-01112011-112909/.
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As ligas de Al utilizadas na indústria aeroespacial com finalidade estrutural apresentam microestrutura complexa devido aos tratamentos termo-mecânicos a que são submetidas visando o aumento da resistência mecânica. Estas ligas se caracterizam pela presença de um grande número de intermetálicos (IMs) em sua microestrutura, os quais possuem atividade eletroquímica diferente da matriz provocando problemas de corrosão localizada devido à formação de microcélulas galvânicas. Na última década a espectroscopia de impedância eletroquímica (LEIS) tem se estabelecido como uma poderosa técnica na elucidação de aspectos locais relacionados à corrosão, e também tem servido para estudos de aspectos teóricos referentes à distribuição de potencial e corrente na superfície de eletrodos e suas correlações com a reatividade superficial. Esta técnica se baseia na análise de diferentes impedâncias locais obtidas por meio de um bi-eletrodo posicionado nas proximidades do eletrodo de trabalho. O presente trabalho visa estudar a corrosão localizada da liga de Al 7475-T761, utilizada na estrutura de asas e na fuselagem de aeronaves, em meios contendo íons sulfato por meio de espectroscopia de impedância eletroquímica global (EIS) e por LEIS, associadas à caracterização microestrutural por MEV/EDS. Os resultados dos estudos com as técnicas eletroquímicas globais, juntamente com a caracterização microestrutural, confirmaram que o aumento local do pH devido à reação catódica sobre os IMs é um dos fatores mais importantes na incidência corrosão localizada da liga de Al. Este fenômeno leva à dissolução local da película passiva e a uma importante despolarização da reação de oxidação do Al com grande aumento da corrosão. Já os estudos com o eletrodo de disco rotatório (EDR) mostraram que os íons sulfato melhoram o desempenho da película passiva formada sobre a matriz da liga, e evidenciaram o ataque preferencial dos IMs ricos em cobre por estes íons. No que se refere aos estudos realizados com a LEIS, os mesmos foram desenvolvidos principalmente com pares galvânicos modelos Al 7475/Cu visando simular a atividade eletroquímica que ocorre na interface entre os IMs e a liga. Este enfoque apresentou um aspecto inovador ao empregar pela primeira vez uma liga comercial como um dos componentes de um par galvânico simulado em estudos com a LEIS. Os resultados obtidos com este estudo confirmaram as previsões de modelos teóricos já desenvolvidos para os efeitos da geometria do eletrodo sobre a reatividade na superfície do mesmo, e também mostraram que o bi-eletrodo foi sensível a pequenas mudanças na atividade eletroquímica na interface do par galvânico, o que foi confirmado pelas análises por MEV/EDS. Outro aspecto inovador do presente trabalho com relação ao uso da LEIS foi que, pela primeira vez, foi utilizado um tri-eletrodo para a obtenção dos diagramas de impedância locais. Este sistema permite medir simultaneamente as componentes radial e normal da corrente local, possibilitando um maior refinamento da compreensão dos fenômenos interfaciais locais. Os resultados das medidas com este novo sistema apresentaram boa concordância com o modelo teórico desenvolvido para a resposta de impedância local apresentado neste trabalho, indicando que o mesmo pode se constituir em uma poderosa ferramenta para uma melhor compreensão dos processos interfaciais locais.Aluminum alloys used in the aerospace industry with structural purpose exhibit a complex microstructure due to thermal and mechanical treatments they are submitted for improving their strength. The microstructure of these alloys is characterized by the presence of a great number of intermetallic (IM) particles, the electrochemical activity of which is different from the matrix leading to the onset of localized corrosion phenomena associated with local galvanic cells. In the last decade local electrochemical impedance spectroscopy (LEIS) has been used as a powerful tool to elucidate local features associated with corrosion and also to study theoretical issues related to current and potential distributions at electrode surfaces and their correlation with surface reactivity. This technique is based on the calculation and analysis of different local impedances acquired by a bi-electrode probe positioned in the vicinity of the electrode surface. The aim of the present work is to study localized corrosion of Al alloy 7475-T761, used with structural purpose in aircraft wings and fuselages, in sulfate containing media using global electrochemical impedance spectroscopy (EIS) and LEIS associated with microstructural characterization by SEM/EDS. The results of the investigations with the global techniques together with the microstructural characterization confirmed that local pH increasing at the matrix/IM interface due to the cathodic reaction on the IMs is the most important cause for the localized corrosion of the alloy. This process leads to local dissolution of the passive layer and to an important depolarization of the Al oxidation reaction leading to a great increase in the corrosion rate of the metal. On the other hand the investigations using the rotating disk electrode (RDE) revealed that sulfate ions increase the anticorrosion performance of the passive layer and are particularly aggressive at Cu-rich IMs. Regarding the studies with the LEIS technique they were mainly performed using an Al 7475/Cu model electrode aiming to simulate the electrochemical activity at the IM/alloy interface. This approach was new as, to the best of our knowledge, it was the first time a commercial alloy was used as one of the component of a model electrode for local electrochemical investigation. The results were in accordance with theoretical models already developed for the effects of geometry induced current and potential distributions on the electrode surface reactivity, and also showed that the bi-electrode was sensitive to minute change of the electrochemical activity at the interface of the galvanic couple, which was confirmed by SEM/EDS analysis. Another originality of the present work regarding the use of LEIS was that, for the first time, a tri-electrode was used to acquire the local impedance diagrams. This system allows the simultaneous measurement of the normal and radial components of the local current making possible a better comprehension of the local interfacial phenomena. The results of the measurements with this new system were in good agreement with the theoretical model for the local electrochemical response presented in this work, indicating that it can be a valuable tool for a better comprehension of the local interfacial processes.
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Honč, Jiří. "Charakterizace elektrochemických vlastností hořčíkových baterií při modifikaci elektrolytu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433030.
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This thesis deals with novel electrolytes for magnesium batteries. Prepared electrolytes were composed of affordable solvents and chemicals, which can be handled at normal laboratory conditions. Specifically, solutions of tetrahydrofurane and dimethylsulfoxide with magnesium chloride, aluminium chloride, nitrilotriacetic acid and disodium ethylenediaminetetraacetic acid, were prepared. To determine electrolyte ability of magnesium stripping and deposition, the cyclic voltammetry was used. The kinetics of electrochemical reactions in terms of polarization resistance was studied by electrochemical impedance spectroscopy. Based on scanning electron microscopy and EDS analysis, the effect of atmospheric oxygen and humidity on magnesium electrode corrosion during cycling was discussed.
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Böhm, Jochen. "Identifikation makromolekularer Komplexe in Elektronentomogrammen eiseingebetteter Phantomzellen." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963026232.
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Sabbir, Md Ahsan. "Corrosion Degradation Mechanism of CBPC Coating System for Highway Bridge Steel Components." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3179.
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Coatings are widely used to mitigate corrosion of structural steel in aggressive humid environments. However, the service life is often diminished in aggressive environments. Repair of coatings can be costly due to materials, labor and environmental controls. So, in search for novel coatings, Chemically Bonded Phosphate Ceramic (CBPC) coating was investigated for marine bridge application. The research on CBPC coating considered various exposure environments such as inland, beach, salt-fog, wet and alternate wet and dry exposure to identify the degradation mechanism. To assess the corrosion damage, the coating was evaluated by visual inspection, thickness, adhesion, microscopy and X-ray diffraction.
The CBPC coating degraded initially due to alternate wet and dry exposure. The unreacted coating constituent reacted further in moist environment to form magnesium phosphate hydrate and enhanced bulk coating porosity. That facilitated moisture to the coating substrate and formed apparent protective iron phosphate hydrate by interaction with steel substrate to the coating constituents. Passive-like conditions were observed in wet test of chloride-free solutions for the formation of hydration product of magnesium but that type of hydrate was not identified in chloride solution for the apparent high solubility. The resolved coating impedance parameters were introduced to characterize the bulk ceramic degradation. The solution resistance did show a decrease for all samples due to leaching of minerals from the bulk material. The resolved pore resistance did not show any distinct change, though there was an indication of bulk coating degradation by MIP. Water saturation level during exposure was also calculated from the resolved capacitance. An approach was proposed to transfer the pre-exponential term, Yo to coating capacitance, CC for ceramic coating. The estimated value of the coating capacitance from the developed technique indicated early saturation with water during exposure due to the porosity. So, the extent of CBPC coating permeability and degradation could not be resolved only by conventional analysis approaches. However, the formation of iron hydrogen phosphate hydrate and iron phosphate hydrate from reaction of unreacted coating constituents was thought to provide apparent enhanced corrosion protection but there is a probability of steel substrate corrosion in extended exposure in humid environment.
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Kefallinou, Zoi. "The impact of curing time on the electrochemical behaviour of intact epoxy-phenolic coatings on tinplate and tin-free steel." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/the-impact-of-curing-time-on-the-electrochemical-behaviour-of-intact-epoxyphenolic-coatings-on-tinplate-and-tinfree-steel(21a7c994-fa56-42a9-af86-1ef6f3352821).html.
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Water diffusion is widely believed to be a driving factor in the breakdown of corrosion protection by polymer coatings. However, in the epoxy-phenolic system examined, water absorption into more cured, electrically resistive coatings is shown to increase, contradicting the common perception that hydrophobic coatings yield improvements in corrosion protection. Water uptake into epoxy-phenolic coatings was estimated as a function of time using the dielectric and resistive properties of the coating measured using electrochemical impedance spectroscopy (EIS). Bulk water uptake through the coating surface and the localised nature of corrosive failure was then confirmed using localised electrochemical impedance (LEIS). This technique also allowed comparison of resistance for coatings with different curing degrees. The greater degree of water absorption into highly cured coatings was attributed to diffusion into the polymer free volume, which increases with prolonged crosslinking. Evidence for this mechanism was found in the decreasing density of epoxy-phenolic coatings as a function of cure time. The effect of coating volume was therefore evaluated with respect to the dry coating dielectric properties. Cathodic delamination of the epoxy-phenolic coatings was achieved on tinplated steel substrates, whereas this was not possible from tin-free steel (ECCS). The electrochemical behaviour of these two substrates was examined under the same NaCl concentration, their surfaces were analysed by XPS prior to immersion, and XRD after potentiostatic polarisations. The electrochemical behaviour of the bare substrates was found to be unchanged by heating to the coating cure temperature (within the accuracy of polarisation tests carried out). Nonetheless, the delamination rate of epoxy-phenolic coatings deposited on them was dependent on the coating crosslinking (cure time). The reason coating adhesion selectively failed on tinplate substrates is believed to be the lower concentration of hydroxides on its relatively flat surface, allowing less bonding to take place at the interface with the coating. The impact of the substrate on coating resistivity was further investigated by volume resistivity measurements in the presence and absence of a metallic substrate. The resistivity of free standing films was tested in permeation cells, and showed a direct correlation between the polymer resistivity and the resistivity of the solution in which it was immersed. In comparison, attached films remained highly resistive at all examined concentrations. To conclude, the results presented here demonstrate that water uptake is not as critical to the breakdown in the protection offered by epoxy-phenolics as bonding at the metal-polymer interface. These results suggest that the complex interaction between these two dissimilar materials determines the overall coating electrochemical behaviour.
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Schöder, Sebastian. "Substrate-dependence of the ice premelting at heterogeneous interfaces an X-ray scattering study /." [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-36131.
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Ghasemi, Samira. "Emulsion polymerisation in the presence of hydrophilic comonomers." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/13274.
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Emulsion polymerisations are preferably stabilised electrosterically through the addition of hydrophilic comonomers having carboxyl functional groups. Furthermore, the incorporation of these comonomers can enhance the properties of the final polymer product. Despite their industrial importance, there is a lack of kinetic studies on these systems. The hydrophilic comonomer preferentially polymerises in the aqueous phase, leading to grafted or embedded hydrophilic chains anchored on the particle surface forming a hairy layer. Developing a mathematical model, it was found that the inhibition effects of the hairy layer of poly-AA chains were more profound compared to poly-MAA chains. The copolymerisation of styrene with MAA was monitored using reaction calorimetry technique for the first time. Using this technique, the enthalpy of copolymerisation of styrene with MAA was estimated and it was found that though the enthalpy of copolymerisation of styrene and MAA is lower than that of styrene alone, the heat of reaction was much higher. This was attributed to a higher polymerisation rate in the presence of MAA comonomer. Since various rapid events occur during emulsion polymerisation that may not be detected using temperature monitoring a novel on-line monitoring technique via high resolution electrical impedance spectroscopy (EIS) was developed for this purpose. It was shown that conductance changes with time at 1 kHz could provide information about properties of various stages of emulsion polymerisation systems. At lower frequencies (i.e., 1 Hz), however, EIS data could successfully detect the particle size evolution. Also, the addition of MAA to the reactor facilitated particle formation, and was reflected by a shorter pre-nucleation period compared with similar experiments without MAA. Furthermore, it was observed that polymerisation of MAA preceded that of styrene.
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Hellfritzsch, Volkmar. "Schwierige Familiennamen auf -eis(en) in Sachsen und Bayern." Deutsche Gesellschaft für Namenforschung e.V, 2013. https://ul.qucosa.de/id/qucosa%3A12844.
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The article deals with some selected compound surnames, the roots of which consist of -eis(en) ‘iron’. It provides a revealing insight into their morphology and etymology. The names in question are characteristically distributed in certain regions of Saxony and Bavaria. By metaphorically designating blacksmiths (occasionally even miners or peasants) they turn out to be obsolete dialect words or technical terms for various wrought-iron objects.