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Otimização na alocação dinâmica de veículos no transporte rodoviário de cargas completas entre terminais
(Universidade Federal de São Carlos, 2012-06-01) Vasco, Rejane Arinos; Morabito Neto, Reinaldo
The domain of logistics is concerned with providing customers with the right product in the right place at the right time. In our modern economy, the faster pace and wider scope of logistic operations has led to complex management problems that have drawn the attention of both industry and the academic world Optimizing the number of vehicles for a determined transport system requires a trade-off between the cost of vehicle acquisition and maintenance and the penalties involved in not meeting the requirements of the system. This thesis proposes to contribute to decision making in the operational management of those companies working in the transportation of goods by road, particularly as regards the optimization of vehicle use in freight transfer between terminals. Various operational problems, especially management of the transfer fleet, involves the dynamic allocation of limited resources to meet demand. Specifically, this paper deals with the dynamic (multi-period) vehicle allocation problem (DVAP) in the road transportation of full loads between terminals. The DVAP belongs to that class of problems dealing with dynamic resource allocation and consists of defining the movements of a fleet of vehicles that transport goods between terminals with a wide geographical distribution and which interact among themselves. These movements may be of fully-laden vehicles, unladen vehicles for repositioning or vehicles held at a terminal to meet future demands. Emphasis is given to the characterization of the problem in real situations, mathematical modeling of the problem and the use of operational research techniques in solving the problem. Also, heuristics and metaheuristics such as GRASP, simulated annealing and ant colony optimization are used in the solution. The objective is to determine dynamic allocation and fleet needs in order to minimize operational costs in meeting the demand for services. The main reason for undertaking this work was the possibility of practical application, the development of integer linear programming models and both exact and heuristic methods for solutions, aiming at the practical validation of the approaches in the real operational environment of a Brazilian transport company.
Estratégia de produção em microempresas de marcenaria
(Universidade Federal de São Carlos, 2012-06-01) Guerreiro, Érico Daniel Ricardi; Camarotto, João Alberto; https://lattes.cnpq.br/1427853773681255
Apparently, the small wood furniture factories have an outdated organization of production, however, they are active in the market for quite some time. In order to understand how the manufacturing strategy of small wood furniture factories helps these companies to stay in the market, this paper studies the content of manufacturing strategy, its alignment with the competitive strategy and with the production system. A research methodology combined a cross-sectional exploratory survey with 40 companies and a multiple case research in three companies. It was observed that the manufacturing strategy adopted is aligned with the competitive strategy of companies. It was observed also that the production system is suitable for manufacturing strategy, but results in some incompatibility with the delivery performance and cost. The main limitation of this study is the geographic concentration of companies participants.
Análise por planejamento fatorial da corrosão por pites de aços inoxidáveis duplex em altas concentrações de íons cloreto
(Universidade Federal de São Carlos, 2012-06-01) Barce, Mariana Sanches; Kuri, Sebastião Elias; https://lattes.cnpq.br/6842072916153866; https://lattes.cnpq.br/7501460989131165
The duplex stainless steels UNS S32101 and UNS S31803, hot rolled, were chosen for the study of localized corrosion pitting for presenting interesting properties of mechanical strength and corrosion resistance for the petrochemical industry. The anodic potentiodynamic polarization test was conducted in aqueous solution with concentrations of chloride ions ranging from 30x103 to 250x103 ppm Cl- (LiCl), under 25°C and 40 ° C in an environment saturated with CO2 and aerated. The pitting potential and corrosion potential were statistically analyzed using factorial design 23. The observation of the microstructure and the pits formed were recorded with scanning electron microscopy (SEM). The results show that the decrease in corrosion potential was significantly influenced by the same factors in both steels: saturation with CO2 and the concentration of chloride anions, while the pitting potential was significantly influenced by different factors, depending on the steel used and the environmental conditions. Thus, the decrease in pitting potential of steel UNS S32101 was significantly influenced by temperature, concentration of chloride anions, interaction between these two parameters and saturation with CO2. On the other hand the decrease in pitting potential of the UNS S31803 steel was significantly influenced by chloride concentration, temperature and the interaction of each of these parameters with the saturation of the medium with CO2. Data analysis by statistical method of factorial design showed that not all studied factors affect localized corrosion significantly and that the effect of these factors is not cumulative.
Desenvolvimento de métodos analíticos empregando a espectrometria de absorção atômica sequencial rápida com atomização em chama
(Universidade Federal de São Carlos, 2012-06-01) Miranda, Kelber dos Anjos de; Pereira Filho, Edenir Rodrigues; https://lattes.cnpq.br/3394181280355442; https://lattes.cnpq.br/0995163494768470
The aim of this PhD thesis was to develop analytical methods employing fast sequential flame atomic absorption spectrometry (FS-FAAS). In the first part of this study, a fast and simple method is proposed for the determination of Cu in sugar cane spirits employing FS-FAAS and the internal standard technique. First, Ag, Bi, Co and Ni were evaluated as internal standards to correct transport interferences caused by the presence of ethanol. The results demonstrated that Ag at a concentration of 2 mg L−1 was effective as internal standard. In the second part of this study, a novel analytical method which consists of a combination of hydride generation and FS-FAAS is proposed. The method developed was employed for the sequential determination of As and Sb at sub-μg L-1 levels in bottled mineral waters. An enhancement in the analytical throughput was obtained when compared with the traditional monoelement HGAAS with a quartz tube atomizer. In the last part of the study, the combination of thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) and FS-FAAS for the sequential determination of Cd, Cu, Pb and Zn was proposed and a significant improvement in the analytical throughput of TS-FFAAS was obtained. Then, an analytical method for the sequential determination of Cd, Cu and Pb in slurries of biological samples by TS-FF-AAS was developed.