The mechanism and the oxidation potential of the dissociative single electron transfer for tetra-n-butylammonium acetate has been investigated via conventional (cyclic voltammetry) and convolution voltammetry. The oxidation potential for tetra-n-butylammonium acetate was determined to be 0.60 ± 0.10 (vs. Ag/ (0.1 M) AgNO₃) in anhydrous acetonitrile. The results also indicated the mechanism of oxidation was concerted dissociative electron transfer (cDET), rather than stepwise as was previously reported. To further investigate the mechanism, a series of aliphatic and aromatic tetra-n butylammonium carboxylates were synthesized and investigated via convolution and conventional methods under anhydrous conditions (propionate, pivalate, phenyl acetate, and benzoate). The reported results showed high reproducibility and consistency with a concerted dissociative electron transfer for aliphatic carboxylates with a systematic shift in the oxidation potentials (0.60 ± 0.09 V for acetate, 0.47 ± 0.05 V for propionate, and 0.40 ± 0.05 V for pivalate) within the series which is expected trend based on radical stabilization energies of the alkyl groups on the aliphatic carboxylates. Hydrogen bonding was investigated as a possible source for the discrepancy between our results and the reported mechanism of the dissociative electron transfer. Because of the extreme hygroscopic nature of carboxylate salts, it was hypothesized that the presence of small amounts of water might alter the reaction mechanism. Deionized water and deuterium oxide additions to anhydrous acetonitrile were performed to test this hypothesis. The mechanism was noted to shift towards a stepwise mechanism as water was added. In addition, the derived oxidation potentials became more positive with increasing concentrations of water. Several explanations are presented with regards to water effects on the shift in the electron transfer mechanism. Indirect electrolysis (homogeneous redox catalysis) was also employed as an alternative and independent approach to quantify the oxidation potentials of carboxylates. A series of substituted ferrocenes were investigated as mediators for the oxidation of tetra-n-butylammonium acetate. Preliminary data showed redox catalysis was feasible for these systems. Further analyses of the electrochemical results suggested a follow-up chemical step (addition to mediator) that competes with the redox catalysis mechanism. As predicted from theoretical working curves, a plateau region in the i_p/i_pd plots (where no meaningful kinetic information could be obtained) was observed. Products mixture analyses verified the consumption of the mediator upon electrolysis, but no further information with regards to the nature of the mechanism was deduced. In a related study the effects of hydrogen bonding and ions on the reactivity of neutral free radicals were examined by laser flash photolysis. The rate of the β-scission of the cumyloxyl radical is influenced by cations (Li⁺ > Mg²⁺ ≈ Na⁺ > ⁿBu₄N⁺) due to stabilizing ion-dipole interactions in the transition state of the developing carbonyl group. Experimental findings are in a good agreement with theoretical work suggesting metal ion complexation can cause radical clocks to run fast with a more significant effect if there is an increase in dipole moment going from the reactant to the transition state. / Ph. D. / Our work focuses on employing electrochemical techniques to investigate single electron transfer processes, which lead to unstable organic species that contain an odd number of electrons called radicals and radical ions. Many essential biological and environmental pathways are found to occur via radicals, i.e. photosynthesis, atmospheric degradation, enzyme catalyzed reactions in biology, autooxidation, DNA mutations, and more. Electrochemical techniques permit us to investigate the scientific fundamentals of radical processes by generating radicals and radical ions in a controlled manner with a higher efficiency. We have combined electrochemical techniques with established physical organic theories of electron transfer to allow us to determine of the rate and mechanism of electron transfer for a selective group of chemical compounds, specifically anions derived from carboxylic acids (carboxylates). A fundamental understanding of single electron transfer processes for carboxylates allows for a prediction of chemical behavior and the future design of novel chemical compounds for alternative chemical functionality. Our findings are the first to report experimental evidence for a so-called concerted dissociative electron transfer mechanism for carboxylates, where the transfer of an electron is accompanied by the simultaneous breakage of a carbon-carbon bond yielding a radical and carbon dioxide. The mechanism has been shown to proceed in a stepwise fashion only in the presence of water. Our work highlights the environmental effects on radical stability such as water and metals ions.

In order to achieve global carbon reduction targets, buildings must be designed to be energy efficient. Building performance simulation methods, together with sensitivity analysis and evolutionary optimization methods, can be used to generate design solution and performance information that can be used in identifying energy and cost efficient design solutions. Sensitivity analysis is used to identify the design variables that have the greatest impacts on the design objectives and constraints. Multi-objective evolutionary optimization is used to find a Pareto set of design solutions that optimize the conflicting design objectives while satisfying the design constraints; building design being an inherently multi-objective process. For instance, there is commonly a desire to minimise both the building energy demand and capital cost while maintaining thermal comfort. Sensitivity analysis has previously been coupled with a model-based optimization in order to reduce the computational effort of running a robust optimization and in order to provide an insight into the solution sensitivities in the neighbourhood of each optimum solution. However, there has been little research conducted to explore the extent to which the solutions found from a building design optimization can be used for a global or local sensitivity analysis, or the extent to which the local sensitivities differ from the global sensitivities. It has also been common for the sensitivity analysis to be conducted using continuous variables, whereas building optimization problems are more typically formulated using a mixture of discretized-continuous variables (with physical meaning) and categorical variables (without physical meaning). This thesis investigates three main questions; the form of global sensitivity analysis most appropriate for use with problems having mixed discretised-continuous and categorical variables; the extent to which samples taken from an optimization run can be used in a global sensitivity analysis, the optimization process causing these solutions to be biased; and the extent to which global and local sensitivities are different. The experiments conducted in this research are based on the mid-floor of a commercial office building having 5 zones, and which is located in Birmingham, UK. The optimization and sensitivity analysis problems are formulated with 16 design variables, including orientation, heating and cooling setpoints, window-to-wall ratios, start and stop time, and construction types. The design objectives are the minimisation of both energy demand and capital cost, with solution infeasibility being a function of occupant thermal comfort. It is concluded that a robust global sensitivity analysis can be achieved using stepwise regression with the use of bidirectional elimination, rank transformation of the variables and BIC (Bayesian information criterion). It is concluded that, when the optimization is based on a genetic algorithm, that solutions taken from the start of the optimization process can be reliably used in a global sensitivity analysis, and therefore, there is no need to generate a separate set of random samples for use in the sensitivity analysis. The extent to which the convergence of the variables during the optimization can be used as a proxy for the variable sensitivities has also been investigated. It is concluded that it is not possible to identify the relative importance of variables through the optimization, even though the most important variable exhibited fast and stable convergence. Finally, it is concluded that differences exist in the variable rankings resulting from the global and local sensitivity methods, although the top-ranked solutions from each approach tend to be the same. It also concluded that the sensitivity of the objectives and constraints to all variables is obtainable through a local sensitivity analysis, but that a global sensitivity analysis is only likely to identify the most important variables. The repeatability of these conclusions has been investigated and confirmed by applying the methods to the example design problem with the building being located in four different climates (Birmingham, UK; San Francisco, US; and Chicago, US).

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / Use of top-down design principles and standard interface techniques provides the basis for a global telemetry data collection, analysis, and satellite control network with a high degree of survivability via use of distributed architecture. Use of Commercial Off-The-Shelf (COTS) hardware and software minimizes costs and provides for easy expansion and adaption to new satellite constellations. Adaptive techniques and low cost multiplexers provide for graceful system wide degradation and flexible data distribution.

The central theme of this thesis is the construction of simultaneous confidence regions (SCR) corresponding to stepwise multiple comparison procedures (MCP). The first chapter is devoted to the theory of multiple comparisons, including the class of closed testing procedures which contains every MCP that strongly con- trols the familywise error rate. The second chapter is concerned with the gene- ral principle of construction of SCR corresponding to closed testing procedures. These general results are used in the third and the forth chapter for deriving the SCR corresponding to a subclass of closed testing procedures which are based on weighted Bonferroni tests. The SCR corresponding to the Holm, the Holm(W), the fixed-sequence and the fallback MCP are derived explicitly. The theoretical results are numerically illustrated on a bioequivalence study. In the fifth chapter we briefly discuss the SCR corresponding to the Hommel, the Hochberg and the step-down Dunnett MCP.

[pt] A empresa petrolífera estudada define a meta para o estoque total de petróleo utilizando inúmeros fatores, porém não considera em sua metodologia os custos despendidos no transporte marítimo. Durações de estadia acima do padrão geram custos adicionais substanciais no processo de movimentação de petróleo e o conhecimento dos fatores que afetam a estadia pode auxiliar na identificação das ações que devem ser tomadas para redução dos custos. Desta forma, com o propósito de contribuir para a redução dos custos de transporte marítimo, o objetivo do trabalho é verificar a dependência entre a estadia de navios em um grande terminal da empresa e outras variáveis da cadeia de suprimentos. Os dados históricos de estadia de navios, estoque, produção, refino, venda e compra de petróleo, nos anos de 2016 e 2017, foram obtidos dos sistemas internos da companhia, e foram avaliados estatisticamente. A regressão que melhor explicou a quantidade de navios aguardando atracação no terminal estudado conteve como variáveis independentes o estoque total da empresa, o refino, o estoque de petróleo dos terminais e refinarias atendidas pelo terminal estudado e o valor da quantidade de navios aguardando atracação no período anterior. Utilizando a equação do modelo selecionado, é constatado que elevações no estoque total de petróleo provocam um aumento no custo de estadia 11 porcento maior que o aumento do custo financeiro do estoque. Assim, com base nos resultados obtidos, esse trabalho propõe que o impacto do nível de estoque na estadia dos navios deve ser considerado no cálculo do estoque meta, o que trará ganhos de dezenas de milhões de dólares ao ano para a empresa estudada. / [en] The petroleum company studied sets the target for the total oil stock using many factors, but does not consider in its methodology the costs incurred in shipping. Length of stay above the standard will generate significant additional costs in the oil transportation. Knowledge of the factors that affect the stay can help identify the actions that must be taken to reduce costs. Thus, in order to contribute to the reduction of shipping costs, the objective of this work is to verify the dependence between the stay of ships in a large terminal of the company and other variables of the supply chain. The historical data on the duration of the ship stay, inventory, production, refining, sale and purchase of oil in the years 2016 and 2017 were obtained from the company s internal systems and were statistically evaluated. The regression that best explained the number of ships waiting berthing at the terminal studied contained as independent variables the company s total oil stock, the refining, the oil stock of the terminals and refineries served by the terminal studied and the number of ships waiting berthing in the previous period. Using the equation of the selected model, increases in the total oil inventory cause a 11 percent higher excess of stay cost than the increase in the financial cost of the stock. Thus, based on the results obtained, this work proposes that the impact of the inventory level on the ship s stay have to be considered in the calculation of the target stock, which will bring tens of millions of dollars a year earnings for the company studied.

The use of remote sensing technology has made it possible for the non-contact measurement of soil moisture content (SMC). Many remote sensing techniques can be used such as microwave sensors, electromagnetic waves sensors, capacitance, and thermal infrared sensors. Some of those techniques are constrained by their high fabrication cost, operation cost, size, or complexity. In this study, a thermal infrared technique was used to predict soil moisture content with the aid of using weather meteorological variables. <p>The measured variables in the experiment were soil moisture content (%SMC), soil surface temperature (Ts) measured using thermocouples, air temperature (Ta), relative humidity (RH), solar radiation (SR), and wind speed (WS). The experiment was carried out for a total of 12 soil samples of two soil types (clay/sand) and two compaction levels (compacted/non-compacted). After data analysis, calibration models relating soil moisture content (SMC) to differential temperature (Td), relative humidity (RH), solar radiation (SR), and wind speed (WS) were generated using stepwise multiple linear regression of the calibration data set. The performance of the models was evaluated using validation data. Four mathematical models of predicting soil moisture content were generated for each soil type and configuration using the calibration data set. Among the four models, the best model for each soil type and configuration was determined by comparing root mean of squared errors of calibration (RMSEC) and root mean of squared errors of validation (RMSEV) values. Furthermore, a calibration model for the thermal infrared sensor was developed to determine the corrected soil surface temperature as measured by the sensor (Tir) instead of using the thermocouples. The performance of the thermal infrared sensor to predict soil moisture content was then tested for sand compacted and sand non-compacted soils and compared to the predictive performance of the thermocouples. This was achieved by using the measured soil surface temperature by the sensor (Tir), instead of the measured soil surface temperature using the thermocouples to determine the soil-minus-air temperature (Td). The sensor showed comparable prediction performance, relative to thermocouples. <p>Overall, the models developed in this study showed high prediction performance when tested with the validation data set. The best models to predict SMC for compacted clay soil, non-compacted clay soil, and compacted sandy soil were three-variable models containing three predictive variables; Td, RH, and SR. On the other hand, the best model to predict SMC for compacted sandy soil was a two-variable model containing Td, and RH. The results showed that the prediction performance of models for predicting SMC for the sandy soils was superior to those of clay soils.

Ride and handling are important areas for safety and improved vehicle control during driving. To meet the demands on ride and handling a number of measures can be taken. This master thesis work has focused on the early design phase. At the early phases of design, the level of details is low and the design freedom is big. By introducing a tool to support the early vehicle body design, the potential of finding more efficient structures increases. In this study, topology optimization of a vehicle front structure has been performed using OptiStruct by Altair Engineering. The objective has been to find the optimal topology of beams and rods to achieve high stiffness of the front structure for improved ride and handling. Based on topology optimization a proposal for a beam layout in the front structure area has been identified. A vital part of the project has been to describe how to use topology optimization as a tool in the design process. During the project different approaches has been studied to come from a large design space to a low weight architecture based on a beam-like structure. The different approaches will be described and our experience and recommendations will be presented. Also the general result of a topology-optimized architecture for vehicle body stiffness will be presented.

The use of remote sensing technology has made it possible for the non-contact measurement of soil moisture content (SMC). Many remote sensing techniques can be used such as microwave sensors, electromagnetic waves sensors, capacitance, and thermal infrared sensors. Some of those techniques are constrained by their high fabrication cost, operation cost, size, or complexity. In this study, a thermal infrared technique was used to predict soil moisture content with the aid of using weather meteorological variables. <p>The measured variables in the experiment were soil moisture content (%SMC), soil surface temperature (Ts) measured using thermocouples, air temperature (Ta), relative humidity (RH), solar radiation (SR), and wind speed (WS). The experiment was carried out for a total of 12 soil samples of two soil types (clay/sand) and two compaction levels (compacted/non-compacted). After data analysis, calibration models relating soil moisture content (SMC) to differential temperature (Td), relative humidity (RH), solar radiation (SR), and wind speed (WS) were generated using stepwise multiple linear regression of the calibration data set. The performance of the models was evaluated using validation data. Four mathematical models of predicting soil moisture content were generated for each soil type and configuration using the calibration data set. Among the four models, the best model for each soil type and configuration was determined by comparing root mean of squared errors of calibration (RMSEC) and root mean of squared errors of validation (RMSEV) values. Furthermore, a calibration model for the thermal infrared sensor was developed to determine the corrected soil surface temperature as measured by the sensor (Tir) instead of using the thermocouples. The performance of the thermal infrared sensor to predict soil moisture content was then tested for sand compacted and sand non-compacted soils and compared to the predictive performance of the thermocouples. This was achieved by using the measured soil surface temperature by the sensor (Tir), instead of the measured soil surface temperature using the thermocouples to determine the soil-minus-air temperature (Td). The sensor showed comparable prediction performance, relative to thermocouples. <p>Overall, the models developed in this study showed high prediction performance when tested with the validation data set. The best models to predict SMC for compacted clay soil, non-compacted clay soil, and compacted sandy soil were three-variable models containing three predictive variables; Td, RH, and SR. On the other hand, the best model to predict SMC for compacted sandy soil was a two-variable model containing Td, and RH. The results showed that the prediction performance of models for predicting SMC for the sandy soils was superior to those of clay soils.

[pt] Esta dissertação aborda o tema de Integração de Projeto e Manufatura, designado pelo acrônimo inglês de DMI (Design-Manufacuring Integration). Trata-se de um novo e crescente campo de pesquisa dentro da Gerência de Operações. DMI é definido como um conjunto de práticas de integração, coordenação e colaboração, que unificam diferentes áreas funcionais da organização (e.g., vendas, marketing, desenvolvimento de novos produtos, manufatura e compras) com a finalidade de criar valor e impacto no desempenho das empresas. Nas últimas décadas, as organizações estão enfrentando uma feroz concorrência e competem simultaneamente em qualidade, eficiência, flexibilidade e entrega de produtos cada vez mais complexos, com ciclos de vida mais curtos e demandas flutuantes. Por conseguinte, requerimentos de sistemas de planejamento e controle em empresas de manufatura são cada vez mais complexos. Esse contexto levanta a seguinte questão de pesquisa: Em diferentes contextos do ambiente em que se desenvolve a organização, as práticas de integração produzem o mesmo impacto sobre o desempenho? Resultados da pesquisa apontam para uma escassez de pesquisas empíricas rigorosas sobre o impacto do DMI no desempenho operacional da manufatura, sob a lente de efeitos moderadores da incerteza do mercado e da complexidade do mercado. Incerteza é entendida como a falta de habilidade de predizer ou prever devido à aleatoriedade do ambiente externo, que não pode ser alterado pelas ações das empresas individuais ou gerentes; e complexidade é entendido como sendo o estado ou qualidade de ser intricado ou complicado. O objetivo principal da Dissertação é identificar e medir o impacto do DMI sobre o desempenho operacional da manufatura, sob o efeito moderador da Complexidade da manufatura e da Incerteza do mercado. Os dados de 725 produtos da indústria de metal e fabricantes de máquinas (ISIC 3.1, código 28-35) foram obtidos em 21 países a partir da quinta rodada do International Manufacturing Strategy Survey e foram usados para testes das hipóteses. As escalas foram validadas por meio da análise fatorial confirmatória e analisadas com regressão múltipla hierárquica passo a passo. DMI impacta positivamente em três dimensões do desempenho operacional da manufatura (qualidade, flexibilidade e entregas). Complexidade da manufatura modera a flexibilidade e entrega, mas não a qualidade. A incerteza do mercado não apareceu como um moderador para a relação entre a DMI e desempenho operacional da manufatura. Profissionais devem perseguir implementações do DMI, em níveis mais elevados de complexidade de manufatura. Mais pesquisas devem se concentrar na incerteza do mercado, e fortalecer o construto de incerteza com a incerteza tecnológica. / [en] Design-Manufacturing Integration (DMI) is a new and growing research field in Operations Management. The primary goal of the Dissertation is to identify and measure the DMI impact on manufacturing operational performance. The research findings point to a paucity of rigorous empirical research on the impact of DMI on manufacturing operational performance under the lens of moderating effects of market uncertainty and market complexity. Data from 725 metal products and machinery manufacturers (ISIC 3.1, code 28-35) in 21 countries from the fifth round of the International Manufacturing Strategy Survey was used for hypotheses tests. Scales were validated with confirmatory factor analysis and analyzed with hierarchical stepwise multiple regressions. DMI positively impact on the three dimensions of manufacturing operational performance (quality, flexibility, and delivery). Manufacturing complexity moderates flexibility and delivery but not quality. Market uncertainty did not appear as a moderator for the relationship between DMI and manufacturing operational performance. Practitioners should pursue DMI implementations, under higher levels of manufacturing complexity. Further research should focus on market uncertainty, and strengthen the construct of uncertainty with technological uncertainty.

Orientador: Carlos Alberto Canesin / Banca: Júlio Borges de Souza / Banca: Denizar Cruz Martins / Resumo: O estudo da confiabilidade operacional de equipamentos se tornou fundamental para as empresas possuírem o devido controle dos seus ativos, tanto pelo lado financeiro quanto em questões de segurança. O estudo da taxa de falha de equipamentos prevê quando as falhas irão ocorrer possibilitando estabelecer atitudes preventivas, porém, seu estudo deve ser realizado em condições de operação estabelecidas e fixas. Os medidores de energia elétrica, parte do ativo financeiro das concessionárias de energia, são equipamentos utilizados em diversas condições de operação, tanto nas condições do fluxo de energia, tais como presenças de harmônicos, subtensões, sobre-tensões e padrões de consumo distintos, quanto pelo local físico de instalação, tais como maresia, temperatura, umidade, etc. As falhas nos medidores eletromecânicos de energia elétrica são de difícil constatação uma vez que a maioria dos erros de medição, ocasionados principalmente por envelhecimento de componentes, não alteram a qualidade da energia fornecida e nem interrompem o seu fornecimento. Neste sentido, este trabalho propõe uma nova metodologia de determinação de falhas em medidores eletromecânicos de energia elétrica ativa. Faz-se uso de banco de dados de uma concessionária de energia elétrica e do processo de descoberta de conhecimento em bases de dados para selecionar as variáveis mais significativas na determinação de falhas em medidores eletromecânicos de energia elétrica ativa, incluindo no conjunto de falhas a operação com erros de medição acima do permitido pela legislação nacional (2010). Duas técnicas de mineração de dados foram utilizadas: regressão stepwise e árvores de decisão. As variáveis obtidas foram utilizadas na construção de um modelo de agrupamento de equipamentos associando a cada grupo uma probabilidade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The operational reliability study of equipments has become primal in order to enterprises have the righteous control over their assets, both by financial side as by security reasons. The study for the hazard rate of equipments allows to foresee the failures for the equipments and to act preventively, but this study must be accomplished under established and fixed operation conditions. The energy meters, for their part, are equipments utilized in several operating conditions so on the utilization manner, like presence of harmonics, undervoltages and over-voltages and distinct consumption patterns, as on the installation location, like swel, temperature, humidity, etc. Failures in electromechanical Wh-meters are difficult to detect once that the majority of metering errors occurred mainly by aging of components do not change the quality of offered energy neither disrupt its supply. In this context, this work proposes a novel methodology to obtain failure determination for electromechanical Whmeters. It utilizes Wh-databases from an electrical company and of the process of knowledge discovery in databases to specify the most significant variables in determining failures in electromechanical Wh-meters, including in the failure set the operation with metering errors above those permitted by national regulations (2010). Two techniques of data mining were used in this work: stepwise regression and decision trees. The obtained variables were utilized on the construction of a model of clustering similar equipments and the probability of failure of those clusters were determined. As final results, an application in a friendly platform were developed in order to apply the methodology, and a case study was accomplished in order to demonstrate its feasibility. / Mestre