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Estudo das propriedades estruturais dos catalisadores de Cu e Cu-Ce suportados em alumina aplicados à reação de deslocamento gás-água
(Universidade Federal de São Carlos, 2013-03-12)
Caldas, Paula Cristina de Paula
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Bueno, José Maria Corrêa
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https://lattes.cnpq.br/0157452280626031
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https://lattes.cnpq.br/3466253594165485
Particle size effect and Ce addition on the catalytic properties of Cu/Al2O3catalysts were investigated for the water gas shift reaction (WGS). The catalysts were prepared by dry impregnation of an aqueous solution of nitrates of the respective metals on alumina, synthesized by sol-gel method. Samples were prepared with 5, 10 and 15% w/w of metallic copper and 12% w/w of CeO2. The catalysts were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR) spectroscopy, X-ray absorption (XAS). The WGS reaction was performed with reagents ratio of H2O:CO = 1:3 with temperature range from 200 to 350° C. The crystallites CuO were not detected by XRD. As the Cu content increased, the crystallite size of CeO2 decreased with a fluorite type structure from 7.4 to 3.4 nm. The results of TPR showed that the interaction Cu-O-Al was crucial to reduce temperature and ceria addition on the catalysts did not affect the temperature reduction of the CuO. The XANES in situ results along the WGS reaction showed that metallic Cu predominated and ceria was partially reduced. EXAFS results showed that the Cu particle size increased from 0.65 to 0.91 nm with an increased load of copper from 5 to 15%, respectively. After the reduction, step prior to reaction, the catalysts were not completely reduced. The degree of reduction increased with the Cu particle size and it was also dependent on the temperature and the oxidation potential of mixing of the reactants. The addition of ceria did not change the degree of reduction of samples Cu/Al2O3. The results suggest that the Cu particles have a reduced Cu core covered with an oxide layer. The catalytic activity increased as the Cu particle size decreased, which can be associated with the presence of the redox couple Cu+/Cu0. This provides a possibility of CO oxidation and its reoxidation due to water activation. The ceria addition also increased catalytic activity and it is probably attributed to activation of the water on the surface of ceria, followed by transfer of oxygen from its structure to the oxidation of CO in an interface Cu-CeO2.
A educação escolar na arena do ciberespaço
(Universidade Federal de São Carlos, 2013-03-12)
Oliveira, Alessandro Eleutério de
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Zuin, Antônio Álvaro Soares
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https://lattes.cnpq.br/5543562307373287
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https://lattes.cnpq.br/3800768997086874
The objective of this study is to examine virtual communities dedicated to the School Education site relationships Orkut. Accordingly, we analyze written statements from teachers and students in order to apprehend the ways in which those involved in the teaching-learning perceive each other. That is, how students express themselves about their teachers, as teachers are manifested on students and how teachers and students are manifested on School Education. The rationale for this research is the need of understanding the ways in which the subjects' school experiences are expressed in cyberspace. The examination of the information contained in written statements made effective border methodological content analysis. Thus, the lucubrations are lit mainly by authors of Critical Theory, as Theodor Adorno and Walter Benjamin, by the confluence of the material collected in virtual communities on topics such as disorientation and semi-formation in contemporary as well as your reflexes in Brazilian School Education. Other authors provide important contributions to the construction of this paper are Richard Sennett, Charles Melman and Zygmunt Bauman. To date, the categories derived from the analysis of the data show the existence of largely negative perceptions of teachers on students, and vice versa, from experiences of these subjects in the teaching-learning process. This occurs in a context of reification and fragmentation of socio-cultural, which damages the formative experience. This process hinders the effectiveness of dialogic praxis, which is fundamental to the success of School Education
Microestrutura e propriedades mecânicas de vitrocerâmicos do sistema Li2O – CaO – SiO2
(Universidade Federal de São Carlos, 2013-03-12)
Santos, Gisele Guimarães dos
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Zanotto, Edgar Dutra
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https://lattes.cnpq.br/1055167132036400
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https://lattes.cnpq.br/0761705816463042
An interesting characteristic of the Li2O-CaO-SiO2 glass-forming system is the possibility of obtaining certain crystalline phases and morphologies that may lead to tough glass-ceramics. However, very few published works investigated this matter. Glass compositions within the range 30-50% CaSiO3 / 70-50% Li2SiO3 were studied to obtain appropriate microstructures. Heat treatments were conducted using the double treatment technique: nucleation at about the glass transition temperature followed by crystal growth within the temperature range 500 and 700°C. These temperatures were selected according to DSC data. The influence of the size, number and morphology of the crystals on certain mechanical properties of the glass-ceramics, such as hardness and indentation toughness, were estimated by Vickers indentation tests. The samples were also characterized by X-ray diffraction to identify the phases present and by MEV to examine the crystal size, percentage and morphology. The best results were obtained with a composition of 44% mol CaSiO3 using the following thermal treatment conditions: 498°C for 24 hours (nucleation) and 700°C for 2 hours (Crystal growth), that led to a glass-ceramic showing a toughness of 1,9 MPa.m1/2.
Desenvolvimento, perícia e poder no rural paulista : o caso do Programa Estadual de Microbacias Hidrográficas
(Universidade Federal de São Carlos, 2013-03-12)
Gameiro, Mariana Bombo Perozzi
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Martins, Rodrigo Constante
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https://lattes.cnpq.br/6617183095074852
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https://lattes.cnpq.br/5015952241455361
This research analyzes the relations established by agents with the expert knowledge in the context of a public policy for rural development, by reconstructing the experiences of those who took part of its processes of formulation and implementation. These processes are often mediated by funding institutions and rural extension agencies. Analyzing social phenomena from the perspective of mediations, and more specifically, from the perspective of expertise, assumes the centrality of power dimensions, the identification of its asymmetries and constant disputes over the construction of views about ruralities. The object of this study is the Land Management III Project (Programa Estadual de Microbacias de São Paulo - PEMH), one of the first public policies with a territorial, decentralized and participative approach for the sustainable rural development of the State of Sao Paulo. This program was partially financed by the World Bank and executed between 2000 and 2008 by the State Secretary of Agriculture, through its rural extension body, the Coordination of Integral Technical Assistance (CATI). The problematization of this research was designed from Anthony Giddens concept of systems experts, from whom we also extracted the notions of reflexivity, agency, time and space. Manuel Castells concepts of space of flows and space of places also assisted in the interpretation, as well as Michel Foucault's formulations on discourse. The field researches required the contributions of Luc Boltanski and Erving Goffman on trust and interaction processes. Techniques of social qualitative research, such as interviews and document analysis, were employed.
Efeitos de variáveis de procedimentos de treino para o estabelecimento do controle contextual de relações condicionais e de equivalência
(Universidade Federal de São Carlos, 2013-03-13)
Castro, Tatiane Carvalho
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Goyos, Antônio Celso de Noronha
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https://lattes.cnpq.br/3407008711535651
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https://lattes.cnpq.br/8320755140772016
Studies about the effects of contextual control over equivalence classes have been conducted since the 1980s and a relevant question in this area, both in terms of experimental and applied research, is whether changes in contextual variables could result in changes in classes originally formed under different contextual variables. This research investigated, in four studies, the effects of procedures for establishing the contextual control of conditional relations and equivalence classes. The participants were undergraduate students. The stimuli used as sample and comparison were abstract figures and the contextual stimuli were represented by the colors of the background on which the stimuli were presented. In Study 1, we conducted a procedure for the formation of equivalence classes on backgrounds of red and blue colors. Later we conducted a test that showed the equivalence relations in the presence of contextual stimuli blue, red and green. The results showed that participants had responses consistent with the last equivalence class trained, independent of contextual stimulus. Study 2 replicated the previous study, but tests also showed baseline relations. The results obtained were similar to Study 1. Study 3, initially, partially replicated the procedure of previous studies, only for conditional relations AB and then tested the effects of a conditional discrimination training procedure interspersing the colors of the background. The results revealed that this procedure was most effective in setting the control contextual than those conducted in Studies 1 and 2. Study 4 investigated the effects of a interpersed training procedure for the establishment of the contextual control of recombined conditional relations. The procedure consisted of six phases. Phase1 was conducted a conditional discrimination training interspersing the colors of the background. In Phase 2, we carried out the test of relations trained in Phase1. In Phase 3, tests were conducted in which trials were included with a green background. Phase 4 included the symetry relations. Phase 5 presented the same relations were tested in Step 4, however the configuration of stimulus presentation on the computer screen was different. Finally, in Step 6, a test aimed to verify the abstraction of responding under contextual control, with new stimulus and background colors. The results suggest that the contextual control was established for some of the participants. Investigations about the baseline relations training, specifically the interspersed training , for establishing the contextual control is required to produce more robust results.
Teatro e sociedade em Rousseau
(Universidade Federal de São Carlos, 2013-03-13)
Monzani, Luiz Henrique Alves de Souza
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Nascimento, Luís Fernandes dos Santos
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https://lattes.cnpq.br/3654785629696808
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https://lattes.cnpq.br/5199031927733175
Carnavalização e linguagem: o futebol como dramatização da sociedade brasileira
(Universidade Federal de São Carlos, 2013-03-13)
Bombonato, Pedro Guilherme Orzari
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Miotello, Valdemir
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https://lattes.cnpq.br/9131819326282708
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https://lattes.cnpq.br/4484872576716366
More than just the most practiced and admired sport in Brazil, soccer is constituted as one of the most important element of our country s culture. And as any manifestation of the culture sphere, this sport overlaps an infinite amount of social and linguistic relations that constitutes it sometimes as an attractive and highly competitive sport (commercially), sometimes as a spectacle, metaphor and metonymy of society. In this sense, it can be seen as a major form of dramatization of Brazilian society, as regards the anthropologist Roberto DaMatta. Taking into account the theories of Mikhail Bakhtin about the concepts of carnivalization, play, aesthetics and ethics, the objective of this work is to search for points of intersection between soccer and art such as building an understanding of the sport as a form of social drama. Therefore, beyond the theoretical, it will take into account the analysis of various types of texts that present this sport as the main focus. Thus, we intent to better understand the cultural and linguistic relations which constitute soccer as a fundamental part of the Brazilian cultural context.
Catalisadores de Cu/CeO2 modificados com La aplicados à reação de deslocamento gás-água
(Universidade Federal de São Carlos, 2013-03-14)
Silva, Tatiana de Freitas
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Assaf, José Mansur
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https://lattes.cnpq.br/9563312407691130
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https://lattes.cnpq.br/4435205814755218
The water gas shift reaction (WGSR) is often used in industrial processes in order to increase hydrogen production, as well as to remove quantities of CO in the chains produced by steam reforming of hydrocarbons. In this work, CuO/CeO2 and CuO/CeO2-La2O3 catalysts were prepared for application in the watergas shift reaction. The CeO2-La2O3 and CeO2 supports were prepared by three different methods: Hydrothermal (CeO2-La2O3(H) and CeO2 (H)), Co-precipitation (CeO2-La2O3(CP) and CeO2 (CP)) and Sol-gel ( CeO2(SG) and CeO2- La2O3(SG)). The La2O3-CeO2 supports were prepared according to the following molar ratios: 2:1, 1:1 and 1:2 (CeO2-La2O3). The activated catalysts were tested in the water gas shift reaction at temperatures between 150°C and 350°C and the formed products were analyzed by gas chromatography. The CO:H2O molar ratio used in all catalytic tests was 1:5. The catalysts Cu/CeO2(H), CuO/1CeO2-1La2O3(H), CuO/CeO2(CP), CuO/1CeO2-2La2O3(CP) and CuO/CeO2(SG) were also tested at 350°C for 24 hours in the shift reaction under the ideal situation (Reactor Feed: CO, N2 and H2O) to verify their stability. The catalysts CuO/CeO2 (H) and CuO/1CeO2-1La2O3(H) were also tested in the shift reaction under the real situation (Reactor Feed: CO, H2O, N2, H2 and CO2) for performance evaluation in a situation closer to the actual composition of the products observed at the output of industrial reformers. From the results it was observed that the addition of La to the CuO/CeO2 catalyst led to its structural stabilization by preventing the specific area decrease. The addition of La2O3 to the CuO/CeO2 catalysts caused a higher interaction of CuO with the supports, thereby preventing sintering of CuO, even during the reactions. XANES measurements in situ at the Cu edge confirmed the presence of Cu reduced during the course of the reaction, suggesting the presence of Cu sites with similar electron density. XANES spectra at the Ce edge confirmed that there were small changes in the oxidation state of Ce and that Ce species are more oxidized in the catalyst in which La is present. The presence of La probably contributed to higher stabilization of ceria and increased the mobility of oxygen due to vacancy formation in the CeO2 network. Catalysts whose supports were prepared by the hydrothermal method resulted in materials with higher specific area and higher catalytic activities and were more stable with respect to those obtained by the two other methods, during the 24 hours of reaction at 350°C. Therefore, the Cu/CeO2 (H) and Cu/1CeO2-1La2O3(H) catalysts show to be promising as catalysts for the shift reaction. We also observed that the support preparation process affected some properties of the material, such as phase formed, particle size, metallic area, dispersion, surface area and catalytic performance.
Investigação de processos colisionais e reacionais para cromo e vanádio em interface de espectrômetro de massa com plasma indutivamente acoplado
(Universidade Federal de São Carlos, 2013-03-14)
Salazar, Rodrigo Fernando dos Santos
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Nóbrega, Joaquim de Araújo
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https://lattes.cnpq.br/8833989058164529
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https://lattes.cnpq.br/9370462066771109
The analytical capability of inductively coupled plasma mass spectrometers (ICPMSs) and their wide use in different fields of science are well known. However some drawbacks, such as the occurrence of isobaric and polyatomic interferences and ionic suppression effects are commonly related to this method, mainly for ICP-MSs with quadrupole analyzers (ICP-QMS). Consequently, some elements as Cr and V are negatively affected due to polyatomic interferences caused by Ar, C, Cl, N, O and S species. Along the development of this method, different strategies were proposed such as dynamic reaction cell technologies (DRC) and collision-reaction interface (CRI) in order to correct for these effects. The aim of this thesis was to evaluate the application of CRI and DRC interfaces for polyatomic interferences correction affecting Cr and V determination. Solutions containing from 1000 up to 10000 mg L-1 of C, Cl, N and S were employed in order to evaluate polyatomic formation and correction of their effects with both devices. Helium and H2 were used as collision reaction gases through the skimmer cone in the ICP-QMS-CRI whereas NH3 was introduced into the DRC-ICP-QMS. These solutions contained 5 Sg L-1 of Cr and V. The figures of merit evaluated were: limits of detection (LOD, ng L-1), background equivalent concentration (BEC, ng L-1) and signal-to-background ratio (SBR) for instrument optimization and sample preparation based on microwave-assisted digestion (MAD), microwave induced combustion (MIC) and sample dilution with internal standardization for different samples were investigated. It was observed that the collision and reaction devices employed led to improvements of SBR, BEC and LOD values for Cr and V from 5 to 100-fold when compared with measurements without using either CRI or DRC. However, signal intensities for Cr and V with both devices decreased when compared with signal intensities obtained with pure analytical solutions. Losses of signal intensities were more critical in ICP-QMS-CRI, independently on the gas (20 mL min-1 He or H2), than in DRC-ICP-QMS (0.5 mL min-1 NH3). Consequently, better LOD and BEC values were achieved for DRC than CRI for Cr and V determinations in crude oil samples from three different sources and lubricant oil. Finally, it could be pointed out that both systems presented advantages and disadvantages that will depend on the analytical task but spectral interferences caused by concomitants could be solved using both devices.
Continuidade de atratores para problemas parabólicos semilineares sob perturbações do domínio
(Universidade Federal de São Carlos, 2013-03-14)
Samprogna, Rodrigo Antonio
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Silva, Karina Schiabel
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https://lattes.cnpq.br/2677541143976758
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https://lattes.cnpq.br/4957079152385362
In this work we will obtain the continuity of attractors for semilinear parabolic problems with Neumann boundary conditions relatively to perturbations of the domain. We will show that, if the perturbations on the domain are such that the convergence of eingenvalues and eingenfunctions of the Neumann Laplacian is granted then we obtain the upper semicontinuity of the attractors. If, moreover, every equilibrium of the unperturbed problem is hyperbolic we also obtain the continuity of attractors
Avaliação do retardamento do desenvolvimento de plântulas de espécies arbóreas nativas
(Universidade Federal de São Carlos, 2013-03-15)
Banci, André Moisés
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Gandolfi, Sergius
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https://lattes.cnpq.br/4507066244348106
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https://lattes.cnpq.br/6660367966334883
Due to the high rates of environmental degradation and their consequences to the population, environmental recovery in many areas is an urgent need. Recovering degraded areas may be done by using several techniques alone or in combination. The traditional recovery system by means of seedling planting is expensive and has limited guarantee of germination using no-tillage sowing. Therefore, this study tested the viability of experimentally growing seedlings from seven native tree species without them suffering significant changes, after storing the sprouts in cold chambers for periods ranging from 7 to 28 days. The results showed that it is possible to delay the growing of radicles in seedlings stored in cold chambers (15°C) when compared to seedlings stored in germinator (25°C). In four out of seven species (Marlierea eugeniopsoides, Cordia americana, Cedrela fissilis e Hymenaea courbaril) stored for 14 days in cold chambers, the seedlings survival rates were higher than 77% 60 days after they were seeded in the nursery containers. This survival rate was similar to the rate of seedlings not stored in cold chambers. In three species (Marlierea eugeniopsoides, Luehea grandiflora e Hymenaea courbaril) stored for 21 days the survival rates were higher than 75%. The species Marlierea eugeniopsoides did not show significant survival changes even after storage in cold chamber for 28 days.
Inserção japonesa sobre a Ásia através de instituições de cooperação e fomento: modelo para o Brasil na sua consolidação na América do Sul
(Universidade Federal de São Carlos, 2013-03-15)
Chiarelli, João Rodrigues
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Braga, Maria do Socorro Sousa
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https://lattes.cnpq.br/2311094074614215
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https://lattes.cnpq.br/8642786083995896
This paper analyzes the capacity of Regional Cooperation by the Japanese state and the advantages obtained through strategic management of state institutions. For this research, take focus on internal historical factors and key political actors who led Japan's to become a Soft Power agent. The ultimate goal of this research is a timely contribution on the Japanese experience in the field of cooperation that may be of relevance for Brazilian diplomacy and expanding national Soft Power.
Negro intelectual, intelectual negro ou negro-intelectual: considerações do processo de constituir-se negro-intelectual
(Universidade Federal de São Carlos, 2013-03-15)
Oliveira, Evaldo Ribeiro
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Silva, Petronilha Beatriz Gonçalves e
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https://lattes.cnpq.br/2447899367873195
This research entitled "Black Intellectual, Intellectual Black or Black-Intellectual: notes of the process of becoming Black-intellectual", aimed at understanding processes in which Black men and women have made himself / herself in intellectual and identify their experiences of men and women Blacks to form up and intellectuals can contribute to the education of ethnic-racial relations. For this purpose, I make the use of the research question: What processes are present in the form themselves as Black intellectuals? The methodology of the present research is based on principles of Phenomenological that inspires the researcher's stance in relation to the object of research, the research participants, the processes of collecting, analyzing and interpreting data. There were three in-depth conversations with professionals, self-identified Blacks, recognized as intellectuals, with the goal of understanding the meanings of processes experienced by Black men and women as they constitute intellectual. The research allowed an understanding that to constitute themselves as Black and as intellectual, there is a mutual strengthening of both: the Black person and the community to which they belong. Also identified not only studies schools and universities as places of education but also family influences, sensitivity to perceive and study social realities that affect Blacks and especially coexistence and fights with the Black Movement. The Black intellectuals seek to act in the community, in dialogue with the Black community, with other intellectuals and society in general. Its education proceeds in the following dimensions: Becoming Black: a testimony of Blackness; Digging spaces: actions, reactions and joints; Definitions and ide as of who is Black intellectual; Persistence and Militancy: as if you re working out in cold iron.
Avaliação do pensamento contrafactual na depressão
(Universidade Federal de São Carlos, 2013-03-15)
Faccioli, Juliana Sarantopoulos
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Schelini, Patrícia Waltz
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https://lattes.cnpq.br/6185333517392859
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https://lattes.cnpq.br/0106802523076912
Counterfactual thinking (CT) corresponds to the idea of mental constructions of alternatives for past event and serves an important function in an individual s adaptation and emotional coping. The aims of this study were to: (1) produce material to access and evaluate the counterfactual thinking of adults and (2) investigate the counterfactual thinking of depressed and non-depressed people, in order to determine if there are differences in how these two groups think about alternatives to reality. Five stories were prepared, using materials extracts from studies of counterfactual thinking, newspaper report and magazines articles. For each story, we formulated questions about thoughts related to the content read and about how these stories might have been different. The alternatives were formulated using aspects of reality most commonly modified by people, according to the literature: action or inaction, obligation, time and unusual events. Judges evaluated the texts and the questions, and ranked the alternatives provided according to aspects of reality that were modified. These materials were then used with 42 adults (85% female, mean age of 43 years). Subjects belonged one of two groups: depressed and non-depressed. Individual interviews were conducted. Initially, participants indicated their reactions to the stories then indicated modifications they would make, and then selected one of a pre-determined list of possible changes. The verbal responses of both groups were categorized using content analysis, and the frequency of responses, for each category, was compared using Student s t-Test. There were similarities in the CT for both groups. The majority of the CT was categorized as upward, subtractive, self-directed and refered to modifications in action or inactions. Few differences between the two groups were observed, mostly found through directed modifications.
Secagem convectiva de folhas de hortelã: análise baseada no ajuste de correlações empíricas, superfícies de respostas e redes neurais
(Universidade Federal de São Carlos, 2013-03-15)
Costa, Ariany Binda Silva
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Ferreira, Maria do Carmo
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https://lattes.cnpq.br/7070885875161111
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https://lattes.cnpq.br/9518055204202962
Mentha x villosa H. is a species of mint popularly known as regular mint. Besides being widely used as a spice, their leaves yield an essential oil with many healthy compounds that are commonly used in formulation of medicinal and cosmetic products. Convective drying is an interesting alternative to preserve such compounds, but because the oils are rich in aromatic constituents, and the leaves are fragile material, heating must be moderate and proper drying techniques have to be used. In the present work, the drying of mint leaves was investigated in two types of equipment, namely a natural convection oven and a forced convection horizontal dryer. The fresh leaves were initially characterized by measuring their dimensions, bulk density and moisture content. The influence of air temperature, size and growing stage of leaves on the drying kinetic curves was investigated initially for drying in the natural convection oven. The results showed that only the temperature affected the drying rates, while the size or growing stage had no significantly effect on the process. For forced convective drying, the influence of air temperature, air velocity and mass of the samples was investigated. The temperature was the variable with stronger influence on the drying curves. The mass of the sample affected the drying kinetics only at the highest temperature (60 oC), while the influence of air velocity was weak for most conditions. Empirical and semi-empirical models were fitted to experimental data of dimensionless moisture content versus time. The models from Page and Henderson-Pabis provided the best fittings to the experimental data, depending on the mass of the sample. To complement the analysis, multiple regression models based on surface responses were fitted to experimental data. Also, a neural network model was built to simulate experimental data. The resulting network needed seven neurons to represent satisfactorily the drying kinetic data, and provided excellent estimates of experimental results.
Compósitos de matrizes poliméricas com mantas aleatórias de fibras vegetais de sisal e de coco
(Universidade Federal de São Carlos, 2013-03-15)
Darros, Andressa Bella
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Paiva, Jane Maria Faulstich de
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https://lattes.cnpq.br/7926832511513537
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Botaro, Vagner Roberto
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http://lattes.cnpq.br/2907189124654066
The search for new materials in order to alleviate the environmental problems have encouraged the use of raw materials of natural origin to replace, at least partially, to synthetically produced. Vegetable fibers may be used for incorporation into composites of polymer matrices, being renewable, biodegradable and non-toxic. However, generally vegetable fibers exhibit lower mechanical and thermal properties due to the components present in the fiber (cellulose, hemicellulose and lignin) when compared with high performance fibers such as glass fibers and carbon. In general, polymeric matrices can be of three types; thermoset, thermoplastic and thermoplastic biodegradable. In this paper, polymeric matrices and composites of polymer matrices were obtained with the use of random webs of coconut fibers and sisal fibers by compression molding in a hydraulic press. This study involved a comparative study of composites molded polymer matrices with their epoxy resin, polypropylene (PP), and polyhydroxybutyrate (PHB) without fiber. Were performed some types of thermal and mechanical tests for all molded materials. The techniques used were differential scanning calorimetry (DSC), thermogravimetry (TG), dynamic mechanical thermal analysis (DMTA) in bending mode, and mechanical tests of flexural and tensile before and after conditioning in air chamber, with temperature and humidity. The results of flexural tests to room temperature for composites of epoxy resin and PHB values were similar in the resistance of materials when compared to the respective polymer matrix without fibers. The composite of PP / sisal fibers showed a higher resistance when compared to PP without fiber, related to good fiber-matrix interaction. Flexural and tensile tests of specimens after the conditioning chamber for acclimatization showed decreases in resistance of all materials, being more pronounced for composites due to high moisture absorption of natural fibers. The results of DMTA before conditioning showed an increase in E' of the composites of epoxy resin as compared to the epoxy resin without fibers, because the fibers restrict the movement of the molecular chains located at the interfacial region. Relative to PP, composite PP / sisal fibers had an E' greater. The PHB without fibers showed a modulus greater than the composites containing coconut fiber and sisal fibers. DMTA analyzes performed on materials post conditioning decreased in modules, due to weakening of the fiber-matrix interactions.
Influência da complexidade do substrato na ecologia das comunidades de Chironomidae (Diptera)
(Universidade Federal de São Carlos, 2013-03-15)
Mazão, Gustavo Rincon
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Strixino, Susana Trivinho
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https://lattes.cnpq.br/1804083229761186
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https://lattes.cnpq.br/5483557281653769
With the purpose of elucidating some aspects concerning the importance of substrate spatial complexity to the ecology of Chironomidae (Diptera) family in Cerrado streams, three field experiments were carried out in Ipameri and Mimoso de Goiás Municipalities, Goiás State, Brazil. These experiments are described in three chapters that compose this thesis i) Temporal dynamics of Chironomidae (Diptera) larvae on substrates with different levels of spatial complexity and roughness in a Central Brazil stream; ii) Is substrate complexity important for Chironomidae (Diptera) larvae to resist hydrological disturbance?; iii) Influence of spatial complexity and roughness on Chironomidae (Diptera) assemblages. Artificial substrates with different complexity and roughness levels were fixed in bed streams for colonization of Chironomidae larvae. Samplings were taken after a period of 30 days. Results indicated that: i) Colonization of substrates by larvae was not influenced by substrate spatial complexity and no patterns of colonization were observed, considering the various ecological guilds; ii) Both complexity and roughness were not sufficient to maintain the abundance of these organisms, evidencing their sensibility to sudden rain events; iii) Spatial complexity and roughness of substrate influenced the structure of Chironomidade assemblages and were two important aspects to the diversity of these organisms.
Análise ergonômica do trabalho de colheita de citros: comparativo dos métodos de colheita manual e semimecanizado
(Universidade Federal de São Carlos, 2013-03-15)
Costa, Simone Emmanuelle Alves
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Camarotto, João Alberto
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https://lattes.cnpq.br/1427853773681255
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https://lattes.cnpq.br/8806699748610507
The Brazilian citrus business occupies a prominent place in the international market, with great economic and social significance in foreign exchange earnings and employment in the country respectively. In recent decades, the industry has been changing due to cyclical economic reasons, and these changes affect the harvesting process. In this context, the mechanization of the mentioned process diffuses as a possible alternative to reduce costs and increase productivity. However, the adoption of these new technologies in Brazilian orchards lacks analysis from the perspective of health and productivity, as opposed to the consolidated manual harvesting. The aim of this study is to bring a qualitative and quantitative comparison of the impacts on working conditions and productivity, between the use of manual harvesting methods and of multi-platform in São Paulo State orchards. On this purpose, it was used the approach of ergonomics analysis, focusing on activity, evaluating times and repeatability of cycles, as well as the amount of movements performed and energy expenditure for each of the methods. The results indicated a pronounced physical stress on the use of manual harvesting with increased caloric expenditure and amount of movements required to complete the harvest cycle. Despite evidence of work intensification in the use of platforms, this method has increased its viability by reducing the main constraints identified in the analysis of the collector‟s activity, especially those related to the use of stairs, as well as maintaining the quality of the fruit harvested.
Obtenção e caracterização de cimentos sulfobelíticos sintetizados a partir do resíduo de bauxita
(Universidade Federal de São Carlos, 2013-03-18)
Fortes, Gustavo Mattos
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Rodrigues, José de Anchieta
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https://lattes.cnpq.br/4000441989868775
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https://lattes.cnpq.br/7377968371938316
The modern society has an elevated and increasingly pattern of consumption, demanding a high industrial productivity and generating enormous residue volumes, resulting in a conduct that is becoming each time more unsustainable. The bauxite residue (BR), also known as red mud, is the residue of biggest generation by the aluminum industry, being stocked in large impermeable deposits, being this way the passive of the highest management cost for this industrial sector. Only in Brazil the minimum estimative of BR generation is of 10.7 million tons/year. Nevertheless, the BR, although alkaline, is composed by fine particles rich in iron, aluminum and silicon oxides, consisting therefore in a raw material of possible interests for many applications in traditional ceramics, mainly in civil construction. In this alternative, the use of BR, as a raw material, in the development of new sulfobelite cements for civil construction shows itself very attractive. These cements are characterized by the calcium sulfoaluminate phase (C4A3S), higher contents of belite (β-C2S) and calcium ferrialuminate (C4AF), as well as the absence of alite (C3S). Due to this composition these cements have been showing economic-environmental, and possibly even technical, advantages over Portland cement. From their benefits, highlights a reduction of 30% to 62% on equivalent CO2 emissions, as for less limestone used, as well as, lower burning temperature, bringing also energy reduction in the process. The sulfobelite clinker was synthesized using the raw materials: limestone, commercial gypsum, BR and São Simão clay. Using expressive BR content, up to 11.2wt%; understanding the influence of Al2O3/Fe2O3 (A/F) ratio; and gypsum additions; for the synthesis of sulfobelite cements it was possible to develop satisfactory formulations. These sulfobelite cement formulations presented apparent porosity and mechanical strength equivalent to commercial Portland cement (CPII-Z32 and CPV-ARI), else than the formation of hydration products similar to a commercial calcium sulfoaluminato cement.
Estudo da aplicação de filmes automontados de PAH/PEDOT: PSS em membranas de Nafion®
(Universidade Federal de São Carlos, 2013-03-18)
Almeida, Tiago Pedroso de
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Riul Júnior, Antonio
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https://lattes.cnpq.br/0751163307734256
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https://lattes.cnpq.br/7182255791508200
The present work aimed the fabrication of layer-by-layer nanostructured films of poly (allylaminehydrochloride) (PAH) and poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) onto Nafion® 212 membranes. Nafion® is the most used polyelectrolyte in proton exchange membranes (PEM) fuel cells due to its high proton conduction and good chemical stability at ambient temperature. Therefore, this polyelectrolyte presents some disadvantages due to the high methanol permeability when applied in Direct Methanol Fuel Cells (DMFC), reducing drastically the performance of the device. We studied how ultrathin films of PAH/PEDOT:PSS influence the methanol permeability and proton conduction in the LbL modified membranes. Results indicated good adherence of the LbL films onto Nafion® 212 and also good action as a methanol barrier. Nonetheless, together with the methanol blocking there was also a reduction in the proton conductivity, which occurs due to the LbL dipping deposition on both sides of Nafion® 212, trapping water inside the Nafion membrane, and certainly affecting the proton conduction. Moreover, the LbL film deposition might use some important chemical groups present at the Nafion® surface, used to water permeation, also affecting the proton permeation throughout the membrane.