Browsing by Issue Date, starting with "2007-10-04"

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Mecanismos reacionais e os processos de carga e descarga no caso de eletrodos planos de Pb em ácido sulfúrico e formação de eletrodos planos de PbO2 partindo de eletrodos de Pb
(Universidade Federal de São Carlos, 2007-10-04)
Pratta, Patrícia Maria Patrizi
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D'Alkaine, Carlos Ventura
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https://lattes.cnpq.br/8699821828310072
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https://lattes.cnpq.br/8073226929054180
Two systems that form the basis of the lead-acid batteries were studied. The first system was the lead/sulfuric acid (Pb/H2SO4) interface. This interface is equivalent to negative electrode of lead acid batteries. The second system was the lead oxide/sulfuric acid (PbO2/H2SO4) interface. This interface is equivalente to the positive electrode of lead acid batteries. Of these two interfaces the PbO2/H2SO4 interface is the more complex. In order to devise a reproducible method of synthesizing this complexelectrode (and guaranteeing the production of only PbO2), various test were performed probing the electrooxidation of Pb in many different media, including alkaline solution. For both the Pb and PbO2 interfaces, mechanisms of reaction were studied via electrochemical and spectro-electrochemical methods including Fourier Transform Infrared Spectroscopy (FTIR). The behavior of the Pb/H2SO4 system was reproducible and independentof whether the electrode was pure Pb or an alloy of Pb/Ca/Sn/Ag. The reproducibility of measurements in the Pb/H2SO4 system depended on a method developed to remove disrupted filme on the electrode surface. In fact nucleation phenomena were only observed after complete removal of disrupted films from the electrode surface. The formation of reproducible PbO2 films was the main obstacle to obtaining reliable measurements in the PbO2/H2SO4 system. Measurements were sensitive to the planarity of the film and to the presence of excess acid in the solution in which the film was grown.
Composição florística e estrutura fitossociológica de uma floresta estacional semidecidual em Araras, SP
(Universidade Federal de São Carlos, 2007-10-04)
Soares, Marcelo Steinmetz
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Soares, João Juares
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https://lattes.cnpq.br/6093800182799882
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https://lattes.cnpq.br/1377239701436382
The purpose of this study was to analyze the specific composition of tree, arboreal structure, infestation by climbers, canopy layer and compare the results with other forest fragments and, from these, to form a data bank for monitoring. The forest studied is located in the geographical coordinates S 22º 17 and W 47º 24 . The soil is red-dark Latosoil type and its topography is irregular. The floristic analysis was made by expeditions and phytosociology by quadrats of 10x10m in three blocks. The canopy analysis was made by digital image and the climbers infest by coverage index. It was found 114 species belonging to 40 families and 74 genres. It was sampled 728 alive plants. The species with greater importance value were Trichilia clausenii, Galesia integrifolia, Trichilia catigua, Metrodora nigra e Cariniana estrelensis. The sample canopy coverture presented 70% of the samples with 70% of coverture e only 14% with minor than 50%. 83% of the trees presented any infestation by climber and 60% with indice 4 e 5, that was considered elevated. The greatest infestation occurred at the tree of the canopy layer. The population of pioneer species, in the sucessional classification, presented little number of young plants and the secondary and shade tolerant great number and a complete series of diametric classes.
Estudo por espalhamento Raman de efeitos anarmônicos e transição de fase do PbTiO3 : Sm3+ induzidos por pressão hidrostática e variação de temperatura
(Universidade Federal de São Carlos, 2007-10-05)
Machado, Marco Antonio Cunha
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Pizani, Paulo Sérgio
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https://lattes.cnpq.br/1038437165007849
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https://lattes.cnpq.br/5662281567883957
In this work it was investigated, by using Raman spectroscopy, the effect of the substitucional disorder on the vibrational properties of the ferroelectric ceramics PbTiO3 doped with Samarium, at different temperatures and hydrostatic pressures. This material is interesting from the technological point of view because it is a combination between a material with intense ferroelectric properties and a rare earth ion, with very well known optical properties. From the academic point of view, the main purpose was to study qualitatively and quantitatively the combined chemical and structural effects on the phonon spectrum, which was achieved through measurements of the frequency shifts and broadenings of the vibrational modes, that is, the anharmonic effects. It was also investigated the changes in the Curie temperature, the critical transition pressure values and frequency pressure and temperature coefficients generated by substitucional disorder. A special attention was done to the behavior of the lower frequency mode, the so called soft mode, which plays an important role, whose frequency tends to zero with the approach of the ferroelectric-paraelectric transition. The Raman scattering, due to its sensitivity to short range order, to the character nondestructive, noninvasive is a technique well adapted to the purpose of the present study. The importance of the material and the choice of the technique are justified by the great number and quality of publications related to both in the international literature.
A influência dos contextos de produção na carga de trabalho de profissionais de segurança privada.
(Universidade Federal de São Carlos, 2007-10-05)
Greghi, Marina Fonseca
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Camarotto, João Alberto
;
https://lattes.cnpq.br/1427853773681255
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https://lattes.cnpq.br/6957418053245469
The literature affirms that on the last four decades has been occurring a significant raising on the number of private security companies in all over the world. In Brazil, there are estimations which point that there are 1,148 million people working as agents of private security, and this number can reach the house of 2 million people if considered the informal workers. Besides that, there are not many studies about the worker s activities on private security. This paper analyses the activity of the private security officers. It has been utilized foundation from Work Ergonomic Analysis to understand how the operator manages his workload. This paper provides findings about the perception of the private security officers that the mental workload prevails in the activity and that the main constraints are linked with the work organization, including shift work, control and supervision; and variables of consumer attendance. It is concluded that the Context of Production and Service, based on main aspects of work organization, as: prescriptions, work processes, demands of quality and productivity, has decisive influence upon the behavior of the operator. The Context of Production and Service is important to define the workload. In the activity of the professionals of private security the work is prescribed by the independent contractor and the private security company. This mediation is not a prescription that can be easily followed, but a source of constant conflicts, and then it finishes making source of constant conflicts that hold multiple dimensions and finish producing overload for the vigilant thing.
Padrões limnológicos e do fitoplâncton nas fases de enchimento e estabilização dos reservatórios do APM Manso e AHE Jauru (Estado de Mato Grosso)
(Universidade Federal de São Carlos, 2007-10-08)
Figueiredo, Daniela Maimoni de
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Bianchini Júnior, Irineu
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https://lattes.cnpq.br/0659731944736389
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https://lattes.cnpq.br/3560534707014049
This thesis was carried out during the filling and stabilization phases of the reservoirs of APM Manso (Dec/99-Apr/03) and AHE Jauru (Oct/02-Apr/04), in the state of Mato Grosso. It mostly aimed to identify limnological patterns similar to both reservoirs; analyze the influences of river basin, residence time and decomposition process on these patterns; verify the succession of functional groups in the phytoplankton community; and provide a limnological characterization of the tributaries of these hydroelectric reservoirs. In the APM Manso, the flooded area is about 427 km², the residence time (RT) is 429 days; while in the AHE Jauru, the flooded area is about 3 km², and the RT is 4 days. In the former, 11 samplings were conducted during the filling phase (Dec/99- Dezc/00), and 13 during the stabilization phase (Feb/01-Apr/03); the samplings were obtained from seven stations: two in the river, two in the intermediary zone and three in the limnetic zone of the reservoir. In the AHE Jauru, seven samplings were conducted, and the first one was performed one month after the filling was completed, which took three days; the samplings were obtained from two stations: one in the river and one in the reservoir. In both reservoirs, samplings were performed in three different depths in the water column in order to calculate mean, standard deviation and ANOVA. Historic series of weather (precipitation, wind, air temperature) and hydrology (discharge) in the basins of the tributaries of both the APM Manso (Manso and Casca rivers) and the AHE Jauru (Jauru river) as well as the limnological data of these rivers in the period studied were presented and discussed. In the Manso and Casca rivers, rain seasonality was shown to exert strong influence on the major physico-chemical water conditions. In the Juru River, the control was mainly due to the presence or absence of rain close to the collection states. The river conditions were also influenced by their drainage area (geology, soils) and soil uses. In the transition zone of the APM Manso, the oscillations in Secchi disc visibility, turbidity and suspended material were similar to the rivers, with tendency to stabilize in the limnetic zone after March/00. Electrical conductivity, alkalinity and dissolved oxygen were the main indicators of the mineralization process of labile organic matter in the APM Manso (filling phase) and AHE Jauru (Oct-Dec/02), and their patterns were similar to both reservoirs, being mostly controlled by the decomposition velocity. The DO concentrations remained low in the hypolimnion of the reservoirs, which was more noticeable in the APM Manso. The potassium, sodium, magnesium and calcium ions in the APM Manso tended to stabilize after March/00 in this reservoir. In the AHE Jauru, the concentrations of these ions were higher in October/02, with few oscillations and low concentrations in the following months. The mineralization processes of refractory matter, which is abundant in the flooded cerrado vegetation, led to an increment of the nitrogen nutrients (Kjeldahl nitrogen, ammonia, and nitrate) in the APM Manso during the stabilization phase as well as in the AHE Jauru from April to June/03. The residence time was one of the forces which controlled the sedimentation and stabilization processes. The phytoplankton showed functional groups which were generally good describers of the predominant limnological conditions in these reservoirs and their tributaries. In the AHE Jauru, the dominancy among these groups depended on the influence of the Jauru River, which was more perceptible in the rainy period. In the APM Manso, the chlorophyceae were predominant in both filling and stabilization phases; however, the cyanobacteria were also predominant in the latter, possibly due to the increment of nutrients and the decrease in alkalinity. The major limnological patterns identified in the reservoirs were: i) increase in electrical conductivity and alkalinity in the reservoirs (arm of the Casca river in the APM Manso and AHE Jauru); ii) decrease in mean concentrations of DO in relation to the tributaries; iii) increase of Zds and decrease in turbidity and MS (only during drought in the AHE Jauru); iv) increase of phytoplankton density (only during drought in the AHE Jauru). The results suggest that variation patterns in the APM Manso and AHE Jauru continue to occur today and that these environments were stabilized after Dec/00 and Dec/02, respectively
A Força Pública de São Paulo: da profissionalização à sua intervenção no regime militar
(Universidade Federal de São Carlos, 2007-10-16)
Mussolini Filho, Luiz Sérgio
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Martins Filho, João Roberto
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https://lattes.cnpq.br/8157447462904324
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https://lattes.cnpq.br/0728101100072511
The study of professionalization of state military officer constitutes a gap in the National Political Science. In the period comprised between the coming of the French Mission, until we arrieve at the dictatorial period, that started in the year of 1964, with the military coup, we observed through the bibliografhy that some mechanisms of the State, were put in use in a very intenser manner, as to put down civil disturbs, as meetings, public demosntrations and social movements, among them we can mention the student movement. Among the mechanisms of the State, we find in the midst of the Bureau of Public Security, the Public Force, that was used to combat actions of people or groups that contested the Military Regime, actions that not rarely, generated confrontation with parto f the population, students, journalists, teachers, scinetists and even universities. However, the literature about the subject contemplates and restricts itself to the role practiced by militaries constituent of the federal sphere, setting aside, and many times even making reference, to the militaries in the state sfhere.
Efeitos da dragagem sobre a qualidade de sedimentos contaminados do canal do porto de Santos : biodisponibilidade e toxicidade de metais e compostos orgânicos persistentes
(Universidade Federal de São Carlos, 2007-10-19)
Torres, Ronaldo José
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Mozeto, Antonio Aparecido
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https://lattes.cnpq.br/6594211224864538
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https://lattes.cnpq.br/5776197357433580
Contaminated sediments is a worldwide problem, and mobilization of contaminants is one of the most critical issue in environmental risk assessment when dredging projects are concerned. Considering this, we decided to investigate if and how toxic metals and persistent organic compounds such as PAH and PCB are mobilized during dredging operations in the Port of Santos channel (São Paulo State, SE Brazil) in an attempt to assess changes in bioavailability and toxicity of those contaminants. Samples were collected in the dredging site before dredging, in the dredge s hopper (suction hopper dredge) and in the disposal site and its surroundings. Metals and persistent organic compounds were extracted from sediment samples according to USEPA methods for environmental samples. Ecotoxicological assessment was done on bulk sediment samples and in its pore water and elutriate. Results have shown that bulk sediments from the dredging sites are moderately contaminated with As, Pb and Zn and most severely with Hg, as well as had relatively high PCBs and PAHs concentrations (0,8 mg kg-1 for total Hg and 470 μg kg-1 for total PAHs, for example). These results have also shown a 50% increase in the total PAHs concentration in total suspended solids of the water samples collected inside of the dredge s hopper (679 μg kg-1 total PAHs on the total suspended solids against 479 μg kg-1 on bulk sediments from the channel collected on Alemoa terminal). This finding is of great concern as these data refer to the dredge overflow water which is pumped back to the ecosystem during dredging operations. Toxicity tests done with bulk sediment using the amphipod Tiburonella viscana did not show any toxicity, but the tests with the larvae of the sea urchin Lytechinus variegatus showed toxicity to the interstitial waters and elutriates of samples collected in the channel (dredging site), disposal site (sea site) and dredge´s hopper. In this study we also compared the obtained results to the widely used sediment quality guidelines (ERL and ERM), and to a sediment quality assessment scheme (based on various lines of evidence), as well as, to the Brazilian National Council for the Environment resolution called CONAMA 344/04. It can be seen in the results obtained in microcosm experiments (laboratory) that some organic compounds, mainly fluoranthene and pyrene, can be released from the sediments to the water. Such release was detected in the analysis of these compounds adsorbed in semi-permeable membranes (SPMDs) used in these tests. We hope that the results of this study will be used in the future to support a better planning of management strategies in dredging operations and sediment disposal in marine environment in Brazil.
Objetivo da firma e crescimento : um estudo em empresas de base tecnológica
(Universidade Federal de São Carlos, 2007-10-24)
Santos, Daniela Tatiane dos
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Pinho, Marcelo Silva
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https://lattes.cnpq.br/5744234670546601
This dissertation intends to analyze the growth of Technology Based Firms (TBFs) in Brazil linking it with the objectives pursued for them. The TBFs are technologically dynamic companies, with a dense knowledge base that carry throughout radical or incremental technological innovations. Considering the intensity of their technological effort, high growth is expected. However, empirical studies evidence growth records are usually rather moderate. The explanations for this paradox use to emphasize some factors characterized as barriers to growth. Recently, another explicative hypothesis was postulated, concerning to complex configuration of firms objectives and its impact on TBFs growth trends. Thus, this research aims to analyze the objectives of TBFs in Brazil, stressing the importance of growth among them. The empirical research has benefited from available information on the Technology Management Group database (GeTec/UFSCar) on TBFs and in a questionnaire that was sent to a sample of EBTs.
Gestão estratégica de resíduos sólidos: utilização do balanced scorecard
(Universidade Federal de São Carlos, 2007-10-24)
Souza, Ricardo Gabbay de
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Cordeiro, João Sergio
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https://lattes.cnpq.br/2572864522562875
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https://lattes.cnpq.br/7091334915208635
The public sector services are sited in a very dynamic environment, forcing their administrators to have a good perceiving of the internal and external factors that determine the systems reality. Particularly for the solid waste management in Brazil, this universe is defined by political pressures and limitations, influences by population s consuming patterns and environmental inadequacies. For a sustainable development in these systems, it is necessary aligning the many aspects to the sustainability principles, conceiving a strategy for action. Actually a very used tool for strategy management is Balanced Scorecard, which main advantages are: the analysis of organizations positioning under many perspectives, above the strictly financial and operational focus; and the construction of a strategy map, that visually communicates the hierarchy of organizations intended goals. It is also structured a card composed of objectives and their related measures, goals and initiatives, both at organizational and departmental levels. This research analyses the applicability of this method for the solid waste management, using as case a simulated Trust between Araraquara e São Carlos-SP. This permitted working with more than one vision for the strategy, including system s most probable management function workers. The results point to a great applicability of the tool, and instead of the few adequations it was kept the standard structure of the original model, clearly showing a strategic hierarchy from learning and growth and internal processes to society and institutional aspects.
Conservação, viabilidade e vigor de diásporos e crescimento inicial de mudas de aroeira (Myracrodruon urundeuva Fr. Allem.)
(Universidade Federal de São Carlos, 2007-10-24)
Caldeira, Sidney Fernando
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Perez, Sonia Cristina Juliano Gualtieri de Andrade
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https://lattes.cnpq.br/9973185407856723
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https://lattes.cnpq.br/1927097515981523
The increase of the antropic action on the different forms of vegetation imposes the necessity to study the forest species, as much as for its conservation, as for its use in environment and productive plantations. If the species is still widely explored in function of the quality of its wood and of other types of products, they increase the risks for its extinction, and the Myracrodruon urundeuva ( aroeira ) is a species that fits in these aspects. The seed still is the most popular and common form of reproduction of the majority of the forest species, and also for its "ex-situ" conservation. However, the majority of the works on storage is conducted in cold or dry chambers, or its combination, of high cost, for periods around 12 months, and not always they reach the variation of the packages, in relation to the permeability. The option of keeping the quality of diasporas of "aroeira", deriving of seeds collection area, in Cuiabá, Brazil, and cheaper conditions to be stored, and of this form, accessible to more users was evaluated under different forms. In controlled chamber for a conditioning air device, the viability of diasporas of "aroeira" was conserved up to 30 months of storage, while the vigor was kept up to six months, independent of the type of packing used, since the impermeable one, until the total permeate one. In room environment the viability and the vigor were been reduced, at the age of six months, but in lesser speed, when the diasporas were conditioned in packing of can and polyethylene bag; at the age of 12 months the deterioration increased and at the age eighteen it was complete. Positive and significant correlations between the methods of analysis of viability as well as of vigor had been observed. The test of accelerated ageing presented resulted satisfactory to evaluate the quality of the diasporas of aroeira , while the tests of electric conductivity and of the diasporas thousand mass had not been adjusted. The evaluation of the initial development of seedlings, produced from the diasporas stored under different conditions, resulted in lesser values of height, diameter of collar and total dry substance mass, in relation to produced seedlings with the diasporas just harvested. However, with the development of the seedlings, these differences did not remain and presented inferior as well as superior values, in relation to the previous evaluations. It is possible to keep the viability of diasporas of aroeira , for at least up to 30 months, and its vigor up to six months, with its storage in controlled chamber.
Processos educativos da Capoeira Angola e construção do pertencimento étnico-racial
(Universidade Federal de São Carlos, 2007-10-24)
Nogueira, Simone Gibran
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Silva, Petronilha Beatriz Gonçalves e
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https://lattes.cnpq.br/0888248915107906
The research question is: How and under what circumstances, Capoeira Angola´s teachings and learnings contribute to the construction of ethnic-racial belonging in Black professionals with university education? It seeks to identify positive contributions of Capoeira Angola for the construction of the ethnic-racial identity and the overcoming of difficulties in being a professional in an environment mostly white, adverse and hostile to Blacks, such as the university. Theoretical references of the research were based in literature in the field of Education and Psychology, such as: Black Psychology and African Psychology. In order to collect the data two Black angoleiros that made university were visited and detailed conversations was done. Well as, it was made a Circle of Conversations that count on with two mestres and three professores-mestrandos of Capoeira Angola, which contributed to a more collective understanding of how the ethnic-racial belonging can be built inside a group that cultivates African traditions. The study was conducted with inspiration in Phenomenology and data were analyzed based on meanings expressed by the participants. The research shows that Be Black in Brazil is very difficult, but the practice of Capoeira Angola promotes both the psychological health and the strengthening of ethnic-racial belonging both in Blacks and in Non-Black. This happens because the Capoeira Angola educational processes are an anti-racist pedagogy, which encourage both the learning to live in diversity and the learning to fight to transform the society in a place more just, equalitarian and democratic. Thus, it is clear those Capoeira Angola knowledges and their own ways to transmit it, can strengthen the implementation of policies of Affirmative Action in Brazil.
Desenvolvimento de programa livre para análise de pórticos tridimensionais considerando-se a não linearidade geométrica, fissuração do concreto e ligações semi-rígidas
(Universidade Federal de São Carlos, 2007-10-25)
Cotta, Igor Frederico Stoianov
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Carvalho, Roberto Chust
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https://lattes.cnpq.br/3633394168236221
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https://lattes.cnpq.br/2935520478737297
Structural analysis of framed structures using discrete method, wherein, splitting them into elements with simplified considerations, can bring not satisfactory results or end up using very high safety coefficient to the structure. With the growth of computing and microcomputers it is feasible the resolution of structures considering all parts, therefore three-dimensional. The scope of this work is to make a physical and geometrical non-linear analysis of three-dimensional framed structures with re-bar elements, which can be joined by monolithic or semi-rigid connection, that is commonly used in Precast concrete structures. In order to reach this aim, has been developed a free software using PASCAL language and structural matrix analysis, adding up concrete physical nonlinear analysis with Branson expression. The geometric non-linear was considered from a present Lagrangean formulation. In both cases, it was used the incremental loading technique, which showed a very interesting relation between the results. In order to consolidate the studied concepts and to validate the developed software, it was dedicated a special attention to the resolution of several samples, comparing them with the given results of other software and also with values from experimental analysis, specially for the semi-rigid connections
Formação de grãos ferríticos ultrafinos através de transformação de fase induzida por deformação
(Universidade Federal de São Carlos, 2007-10-26)
Ferracini Junior, Elcio Geraldo
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Balancin, Oscar
;
https://lattes.cnpq.br/8379205949387493
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https://lattes.cnpq.br/3886813925202748
One of the key points in steel development has been the refinement of the microstructure, however without change the chemical composition with addition of alloy elements. The refinement of the ferrite grain size leads simultaneously to an increase in strength and toughness. Ultrafine grains can be produced through thermomechanical controlled treatments, generated by dynamic strain-induced phase transformation (g®a), which also can be associated with others dynamic phenomena, such as dynamic recrystallization. In this work a low and a middle carbon steel were previously austenitized at 900ºC for 180 s and cooled at 1ºC/s to a given deformation temperature established in relation to their critical temperatures. The deformation were applied with a strain of 2,5 at a strain rate of 1 s-1. The behavior of the materials during the deformation was analyzed using the stress-strain curves obtained from torsion experiments. After deformation, the samples were air cooled and the final microstructure characterized by scanning electron microscopy. It was determined with success a route capable to produce ultrafine ferrite grains, where grain size of 1,6 μm were produced for the Cos Ar 60 steel and 1,3 μm for the SAE 1548 steel.
Análise química de materiais cerâmicos : digestão por fusão e medidas por ICP OES com configuração axial
(Universidade Federal de São Carlos, 2007-10-26)
Matias, Telma Blanco
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Nóbrega, Joaquim de Araújo
;
https://lattes.cnpq.br/8833989058164529
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https://lattes.cnpq.br/4705647158043150
Ceramic samples are efficiently digested using fusion procedures. However the elevated amounts of dissolved solids in the resulting solutions may cause spectral and transport interferences, affect the analytical blanks and background signals and consequently the limits of detection. These effects can be even worst when measurements are performed using ICP OES with axial view configuration. Therefore, the goal of this thesis was an evaluation of the feasibility of application of an ICP OES with axial view configuration for determination of analytes in complex inorganic samples digested by fusion. The proposal was based on the suitability of fusion procedures for fusion of refractory samples and, on the other hand, the susceptibility of the axial configuration to spectral interferences and effects caused by high concentrations of dissolved solids. The study was carried out using standard reference materials of bauxite, refractory, silicon carbide and glass that were fused using Na+ and Li+ fluxes. All analytes were determined using selected ionic and atomic emissions lines in solutions containing 0.1, 1.1 and 2.2 % m/v of dissolved solids. The instrument was calibrated using analytical solutions prepared in acid or in the reagents media. The ICP OES parameters were optimized in order to obtain robust and non robust conditions according to the Mg II / Mg I ratio. The limits of detection, dynamic linear range, and sensitivity were established. Despite the complexity of the samples, suitable results were obtained for all of them. The most critical aspect was related to the quartz torch lifetime and it was not possible to introduce solutions containing 2.2. m/v of dissolved solids. The deposition of solids in the quartz torch was minimized by increasing the flow-rate of the auxiliary gas to 2.25 L min-1. Severe matrix effects were not observed in robust and non robust operating conditions (recoveries were around 100 + 20 % for minor elements and 100 ± 10 % for major elements). Finally, this research led to the establishment of analytical procedures for each sample material. The best experimental conditions were those that allowed the determination of most analytes in the same sample solution taking into account the multielement capacity of the ICP OES.
Desenvolvimento do sensor baseado em eletrólito sólido de β-alumina para monitoramento de enxofre na indústria siderúrgica
(Universidade Federal de São Carlos, 2007-10-26)
Hasegawa, Haroldo Lhou
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Morelli, Márcio Raymundo
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https://lattes.cnpq.br/0172837599844991
Electrochemical sensors provide real time information of chemical compositions of molten metal. They can be used to improve the control of various metallurgical processes. One of the most successful and widely used electrochemical sensors is the oxygen sensor, based on zircônia solid electrolyte, usually used in steel making. Sensors are being developed for measurement of other chemical elements, but it is very costly and complicated to be produced. In order to solve this problem, in this work synthesis and assembly of β-alumina and β-alumina based on solid electrolyte sensors were studied. For this, the phase of interest was prepared by the mixing of oxides, and characterized. Traditional ceramic forming processes, isostatic and slip casting, were used to produce the prototypes and their ceramic characteristics were evaluated. Both compositions did not present high density after sintering at 1600°C, reaching 90% theoretical density. This fact could be responsible for the break down during the application of the sensors. The Na-β- alumina sensor produced did not present a satisfactory performance for measuring the dissolved sulphur in liquid pig iron. On the other hand, the β-alumina sensor, despite of the secondary phase, showed good behavior in terms of response time (between 5 and 8 seconds) for measuring the dissolved sulphur in liquid pig iron at temperatures from 1440°C to 1460°C, with La2O2SO4 auxiliary electrode and three different reference electrodes. The signal response of EMF between 54 mV and 174 mV was measured in a measuring level from 32 ppm (weight) to 432 ppm (weight) of sulphur dissolved on the metal bath
Desenvolvimento de banhos alcalinos para eletrodeposição de Pb-Sn e Pb-Cu, na presença de aditivo orgânico. Caracterização do processo de eletrodeposição e dos filmes
(Universidade Federal de São Carlos, 2007-10-26)
Siqueira, Joana Luiza Pires
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Carlos, Ivani Aparecida
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https://lattes.cnpq.br/1666217445807782
;
https://lattes.cnpq.br/4650162959340860
Alkaline baths containing sorbitol, tartrate or EDTA were developed in this work for Pb-Sn and Pb-Cu electrodeposition on platinum substrate. The characterization of Pb-Sn and Pb-Cu plating baths by potentiometric titration showed the pH when the species of metallic ions were soluble and stable. The voltammetric curves obtained from these baths indicated that the complexation of metallic ions by sorbitol, tartrate or EDTA, had a beneficial effect, since closed the deposition potential these metallic ions, leading to codeposition of Pb-Sn and Pb-Cu. The analysis of the Pb-Sn and Pb-Cu deposits by x-ray dispersive spectroscopy showed that codeposition of Pb-Sn or Pb-Cu occurred. The codeposition type of Pb-Sn was normal irrespective the additive in the plating bath; the coloration of the films was bright gray and the morphology was formed of refined crystallites. For Pb-Cu alloy the codeposition type was anomalous to the deposits obtained from baths containing sorbitol or tartrate and normal in the presence EDTA. The Pb-Cu deposits obtained in the presence of sorbitol, EDTA or tartrate showed black coloration; or coloration varying of brown to redish or golden to dark redish, respectively. X ray diffraction spectroscopy of the Pb-Sn and Pb-Cu codeposits indicated that these were to constitute a mixture of compounds.
Caracterização eletroquímica de eletrodos de diamante dopado com boro em função de seu pré-tratamento
(Universidade Federal de São Carlos, 2007-10-26)
Carvalho, Adriana Evaristo de
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Rocha Filho, Romeu Cardozo
;
https://lattes.cnpq.br/5200717413563550
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https://lattes.cnpq.br/6039969237116219
The effect of galvanostatic electrochemical pre-treatments on the surface composition and wettability of boron-doped diamond (BDD) electrodes was characterized by X-ray photoelectron spectroscopy (XPS) analyses and contact angle measurements, respectively. The smallest wettability was presented by the least doped as-received BDD electrode; however, the wettability of all the BDD electrodes increased after the cathodic and anodic pre-treatments. From the XPS analyses, an increase in the surface O/C ratio after the anodic pre-treatment was observed, which was attributed to the introduction of carbon-oxygen functionalities on the surface of the BDD electrodes. The effects of the current and charge densities applied on the BDD electrodes, during the cathodic and anodic pre-treatments, were evaluated through the redox reactions of the Fe(CN)6 3-/4- couple by cyclic voltammetry and by electrochemical impedance spectroscopy. The high sensitivity of the electrochemical and electrical properties of this redox couple to the surface terminations of the BDD electrodes was confirmed; the redox reaction kinetics are much faster after cathodic pre-treatments. The electrical properties presented by the BDD electrodes after anodic pre-treatmens, characterized by a resistive response in intermediate frequencies, have been explained as due to a possible partial blocking of the surface, which would be associated to the presence of carbon-oxygen functionalities on the electrodes surface. On the other hand, the electrochemical and electrical properties were shown to be controllably modulated through the galvanostatic electrochemical pretreatments. Studies on these properties were also carried out for the Fe3+/2+ and Ru(NH3)6 3+/2+ redox couples. For the former, contrary to that for the xxiv Fe(CN)6 3-/4- couple, the charge transfer kinetics (slow) become faster after anodic pre-treatments, instead of after cathodic pre-treatments. In the case of the Ru(NH3)6 3+/2+ redox couple, the electrochemical behavior is independent of the electrode surface state, the same being true for the electrical properties, whose use to evaluate the quality of BDD electrodes is proposed. Finally, studies on the ferrocenecarboxylic acid redox species in non-aqueous medium (acetonitrile), in the absence and after additions of water (or glycerol), were carried out in order to investigate the nature of the surface partial blocking of anodically pre-treated electrodes, in the presence of redox couples such as Fe(CN)6 3-/4- or ferrocene. The obtained results indicate that such partial blocking is due to the adsorption of water molecules, by hydrogen bonding with the carbon-oxygen functionalities. This partially prevents the access of the redox reaction to electrochemically active sites, thus explaining why much smaller charge transfer reaction rates are attained when anodically pre-treated electrodes are used.
Uma abordagem de reengenharia iterativa orientada a características para sistemas embutidos legados
(Universidade Federal de São Carlos, 2007-10-28)
Ramos, Marcelo Augusto
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Penteado, Rosângela Aparecida Dellosso
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https://lattes.cnpq.br/4061946080136286
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https://lattes.cnpq.br/9658172103612511
To reduce costs, to minimize risks, to anticipate deadlines and to optimize resources of new product designs it is recommended, whenever possible, to reuse artifacts of existing successful similar products. However, these artifacts must be of easy adaptation to meet the requirements of the new products with a few or no need of re-design or re-coding. This work describes a feature oriented iterative reengineering approach to concomitantly achieve both the revitalization of embedded legacy systems and the incremental creation of a core of reusable artifacts, to support the development of other similar systems, members of a product family. Such systems are generally small and pass through frequent maintenances to support the evolution of the hardware they integrate, accelerating the natural software degradation process. The accomplishment of a reengineering process can extend the life cycle of these systems, improving their structural properties for a better adaptation to changes. Agile principles and techniques are applied throughout the process, providing continuous interactions with the customer and deliveries of executable and tested partially modernized versions in short and frequent intervals, with documentation in appropriate level and prepared for future modifications. Software Product Line techniques are used for the domain modeling and for the design of generic software components. Its activities are accomplished without the need of code freezing or duplication and allow maintenances and interruptions at anytime, without prejudice of the enhancements already developed in all previously ended iterations. A case study is presented to exemplify the proposed approach in a real environment and to evaluate its results.
A seleção de atributos e o aprendizado supervisionado de redes bayesianas no contexto da mineração de dados
(Universidade Federal de São Carlos, 2007-10-29)
Galvão, Sebastian David Carvalho de Oliveira
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Hruschka Júnior, Estevam Rafael
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https://lattes.cnpq.br/2097340857065853
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https://lattes.cnpq.br/8178291602270601
The Knowledge Discovery in Databases (KDD) techniques have grown from the need for obtain more information about the data stored by organizations, such as, enterprise companies and research institutes. Bayesian Networks (BNs) can be considered as a probabilistic reasoning based model to represent knowledge and are very adequate to KDD tasks. In the last years, Bayesian Networks (BNs) have been applied in many supervised and unsupervised learning successful applications. The process to induce BNs and Bayesian Classifiers (BCs) from data tries do identify a BN (or a BC) able to represent the relationship among the variables of a certain data set. However, this is a NP-complete problem and, thus, its search space may become very large in most applications. That is the reason why many algorithms explore some way to reduce the search space in order to make the learning process computationally viable. In this master s thesis a new Conditional Independence based approach to induce BCs from data is proposed and implemented. Such approach is based on the Markov Blanket concept in order to impose some constraints and optimize the traditional PC learning algorithm. Experiments performed with ten data sets revealed that the proposed approach tends to execute fewer comparisons than the traditional PC. The experiments also show that the implemented algorithm produce competitive classification rates when compared with both, PC and NaiveBayes
Desenvolvimento de ferramenta para apoio à gestão de resíduos de construção e demolição com uso de geoprocessamento : caso Bauru - SP
(Universidade Federal de São Carlos, 2007-10-29)
Oliveira, Daniele Meneghetti
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Teixeira, Bernardo Arantes do Nascimento
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https://lattes.cnpq.br/1166854416745527