Browsing by Issue Date, starting with "2007-08-30"

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Processamento da rede neocognitron para reconhecimento facial em ambiente de alto desempenho GPU
(Universidade Federal de São Carlos, 2007-08-30)
Silva, Gustavo Poli Lameirão da
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Saito, José Hiroki
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https://lattes.cnpq.br/7065615446493390
;
https://lattes.cnpq.br/2857602364684106
This work presents an implementation of the Neocognitron Neural Network, using a high performance computing architecture based on GPU (Graphics Processing Unit). Neocognitron is an artificial neural network, proposed by Fukushima and collaborators, constituted of several hierarchical stages of neuron layers, organized in two-dimensional matrices called cellular plains. For the high performance computation of Face Recognition application using Neocognitron it was used CUDA (Compute Unified Device Architecture) as API (Application Programming Interface) between the CPU and the GPU, from GeForce 8800 GTX of NVIDIA company, with 128 ALU s. As face image databases it was used a face database created at UFSCar, and the CMU-PIE (Carnegie Melon University - Pose, Illumination, and Expression) database. The load balancing through the parallel processing architecture was obtained by means of the distributed processing of the cellular connections as threads organized in blocks, following the CUDA philosophy of development. The results showed the viability of this type of device as a massively parallel data processing tool, and that smaller the granularity of the parallel processing, and the independence of the processing, better is its performance.
Determinação e fracionamento de bário em castanha-do- Pará
(Universidade Federal de São Carlos, 2007-08-30)
Gonçalves, Alexandra Mary
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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/1292148611034352
In this work it was studied the determination and fractionation of barium in Brazil nuts employing several strategies for sample preparation and spectroanalytical techniques, i.e. graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma optical emission spectrometry with axial view (ICP OES). Brazil nuts is a widely consummed food due to its nutritional value and good taste. The chemical analysis of Brazil nuts is not trivial due to its complex matrix. The fractionation of barium in Brazil nuts was studied owing to the toxicity of this element and the strong correlation between chemical form and absorption. The total content of barium varied from 860 to 2084 mg/kg. Sequential extractions were performed based on solubility in different media and also lipids, proteins and low molecular weight fractions (LMW). Barium was determined in all extracts by ICP OES. The highest contents of barium were determined in the LMW and insoluble fractions with 778 to 1606 and 551 to 1520 mg/kg, respectively. As expected, these results indicate the unavailability of this element in this food for humans. Based on the contents of barium and sulfur in different fractions and stoichiometric calculations it was possible to infer that barium occurs in the BaSO4 form. The presence of this chemical form was also confirmed by thermogravimetric experiments.
Análise da estabilidade de estruturas pré-moldadas de concreto: influência das ligações semi-rígidas
(Universidade Federal de São Carlos, 2007-08-30)
Jeremias Júnior, Antônio Carlos
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Ferreira, Marcelo de Araújo
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https://lattes.cnpq.br/4199122391532470
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https://lattes.cnpq.br/8002545890872886
This research comprehends a study of the analysis procedures of the global stability in precast concrete structures, considering the effect of the semi-rigid connections. A Look over in the standards and directives of the precast structures project was necessary specifically on the procedures of global stability verification, recommended by the NBR 6118. Besides, it was looked to identify particular situations where the analysis of the precast concrete structures differentiates of the analysis of the structures cast in place. Such discussion is relevant at the moment of the publication of the new NBR 9062, where the effect of the behavior of the beam-to-column connections must be considered in the analysis of the global stability. In the carried through studies, the frame action proportionate by the bending moment resistant beam-to-column connections is a efficient method of bracing of the structure since that the interdependence of some factors is analyzed as the number of the floors, the stiffness and the cracking of columns and the beams and the fixity factor αR. Finally, examples of numerical application are presented with intention to guide the designer of precast concrete structures in the analysis of structures with semi-rigid connections.
Políticas públicas, educação, juventude e violência na escola: quais as dinâmicas entre os diversos atores envolvidos?
(Universidade Federal de São Carlos, 2007-08-30)
Silva, Carla Regina
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Lopes, Roseli Esquerdo
;
https://lattes.cnpq.br/1507752191797249
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https://lattes.cnpq.br/6417501858864106
The present relates to Violence in School according three aspects: youth of popular urban groups; violence in school and education particularly referring to a medium cycle and public school. As effect of process of social fragmentation and economic and social exclusion, it has arisen practices of violence as a social rule of wide groups present in multiple dimensions of human relations and in living together. The relationship between education and processes of violence was connected in every historical constitution of educational institutions and remains until the contemporary society, despite the conceptual transformations that supported its practices through this route. Became evident the vulnerability of youth, mainly of popular groups, given by several numbers related to violence in Country in a context, in which the public politic oriented toward to youth were recognized insufficient, fragmented, or not adequate to accomplish the requirements of that groups, according a point of view that effective them as citizens with full rights. The school has been an important achievement for poor young and teenagers in Brazil, although they have experienced a process of a widening of Medium Cycle full of difficulties and problems, such as minimum standards of quality and completeness in adequate age. Therefore, must be highlighted the importance of commitment of this study deepen and bringing to the context the phenomena of violence in school, related to the political, economical, cultural, and social conditions related to contemporarity, so that it is a urgent matter that blocks the building of democratic process in schools in daily basis. Therefore aiming getting the practices of violence in school environment evaluating the actions and situations experimented relating to this issue by different players in public schools have been worked in a empirical field that aimed five public schools in São Carlos, located in a central region of town. It s been raised related to the issue of school violence, their thoughts regarding school future perspectives of the young people e about school violence and which their way of expression and how has been their struggled. In this sense it was used applications with open and closed questions specific for each category of students and accomplished several individual interviews with employees management teachers parents and students. In the second run of search it was accomplished workshop in which has been deal with issues related to school dynamics and the expression of violence in a qualitative approach of the theme. The results were evaluated, in quantity and quality, using graphic and photographic material, as long the log and the analysis of content of the speech of the players involved. Among analysis of the data gathered, it has been refined the strategies of social inclusion and exclusion process reproduced by school, and the dynamics of school agents related to the violence processes, their reproduction and struggling. In view of density and scope of violence in present days, the school suffers internal and external factors, that are present in daily basis, and face the tough task of conciliating repressive and punishing methods with the challenge of building democratic and participative practices.
Nação e masculinidade em Grande Sertão: Veredas
(Universidade Federal de São Carlos, 2007-08-30)
Almeida, Emerson Rodrigo Ferreira de
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Escudeiro, Richard Miskolci
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https://lattes.cnpq.br/1623888309974862
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https://lattes.cnpq.br/6252186254822704
Estudo de comunidades planctônicas (bacterioplâncton, nanoflagelados, fitoplâncton e zooplâncton) em um pequeno reservatório tropical - experimentos com mesocosmos
(Universidade Federal de São Carlos, 2007-08-31)
Lucinda, Irene
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Melão, Maria da Graça Gama
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https://lattes.cnpq.br/8342306603661310
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https://lattes.cnpq.br/0406853529281876
A leitura na escola : concepções de professores de diferentes disciplinas das séries finais do Ensino Fundamental.
(Universidade Federal de São Carlos, 2007-08-31)
Silva, Maria Vitoria da
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Oliveira, Rosa Maria Moraes Anunciato de
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https://lattes.cnpq.br/3064136997342775
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https://lattes.cnpq.br/9448655452264969
In the exercise of the teaching, teachers of the Final Series of the Fundamental Teaching have come across a significant amount of students that doesn't present necessary basic reading abilities for the learning of specific contents of the several disciplines. In that perspective, we brought up the following research question which guided the present work: How do the teachers of several disciplines of the Fundamental Teaching final series conceive the reading and its teaching? To answer to that questioning we figured out as general objective, to understand the reading conceptions that permeate the teacher's pedagogic practice of the several disciplines of the Fundamental Teaching final series. The theoretical referential is ruled in the studies of Imbernón, Pacheco and Flores, Nóvoa and Mizukami, which have been pointing important contributions for the debate and construction of knowledge on the educational formation and the teacher's professional development and also in the studies of Chartier, Kleiman, Silva, Solé, which conceive the reading as a continuous process, complex and plural, supplying important contributions for its discussion in the education field. The methodological procedures were orientated by the principles of the qualitative research in education, especially the valorization of the teachers' voice, trying to understand their conceptions, their knowledge and faiths as basis of their work with the teaching. As data collection instruments were used the semi-structured interview and the analysis of written materials (course plans, class script and written activities). Five experienced teachers of the disciplines Sciences, Geography, History, Mathematics and Portuguese took part in the research. They teach from 5th to 8th series of the Fundamental Teaching at a school located in the rural area of the municipal district of Feira de Santana, Bahia. The collected data were contained into five analysis dimensions, that is, reading definition, school and reading relationship, reading and specific content relationship, the student's relationship with the reading and the teaching process and reading learning in different disciplines. As result, is possible to stand out that the teachers present in the most conceptual dimensions, a wide, continuous and dynamic conception about the reading. In the dimensions that involve the student and the classroom, a certain distance is verified between what they speak and what the theory proposes. However, it is noticed in the practices reported by the teachers, indications of a search movement for innovation of the daily practices. They recognize the need of the group work involving the whole school around the learning of the reading. We stand out the continuous formation that happens in the exercise of the teaching and in the group work in the school, as a possibility for the teacher to build strategies that contribute with the student's development in what refers to a competent reader's abilities.
Análise de uma experiência de atitudes comunicativas entre mãe e adolescente surdocega: construção de significados compartilhados
(Universidade Federal de São Carlos, 2007-08-31)
Cambruzzi, Rita de Cássia Silveira
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Costa, Maria da Piedade Resende da
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https://lattes.cnpq.br/2791098416503955
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https://lattes.cnpq.br/1324662126060982
The objective of this paper was to identify and analyze the communicative attitudes between a mother and her deafblind adolescent daughter, and also to contribute and promote the development of significant communication between them. In order for this to happen, supporting procedures were employed throughout this research, fomenting the mother as mediator of the process, making her aware of the different communication methods available and teaching her how to apply them to her natural environment, as well as to the social one. The results show significant differences. However, there is need of a broader connection to be established the family, so that the program to be implemented be consolidated in the execution of the activities and, as a consequence carry out the construction process of shared meaning. The journey that begins from this point on seems long. However, the first paces have already been established, renewing our persevering forces
Estudo de Áreas de Preservação Permanente (APP's) de corpos d'água em zonas urbanas como subsídio à legislação pertinente
(Universidade Federal de São Carlos, 2007-08-31)
Padilha, Daniele Corrêa de Castro
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Salvador, Nemésio Neves Batista
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https://lattes.cnpq.br/6943945257521138
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https://lattes.cnpq.br/6943945257521138
The purpose of this paper by performing a bibliographic review and case study, in São Carlos (SP), was to study the application of the Code Forest in Permanent Preservation Areas to urban water courses approaching legal aspects and the others laws corresponding. Like this to reach the problems and conflicts in the application of the Code Forest the use and occupation of the soil. Some subsidies were proposed in order to contribute to the definition of new technical and legal references for a more practical and adequate application of the urban APP, according to the context in which it is inserted on the search for a harmonic acquaintance among Man and Nature.
Macroinvertebrados em córregos da região da Mata Atlântica (Sudeste do Brasil): influência da cultivo de banana
(Universidade Federal de São Carlos, 2007-08-31)
Kleine, Priscilla
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Strixino, Susana Trivinho
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https://lattes.cnpq.br/1804083229761186
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https://lattes.cnpq.br/6360277748362283
The integrity of aquatic ecosystems has been compromised by innumerable anthropogenic actions, for example, extensive agriculture that has been producing alterations in water quality and aquatic community characteristics. Much is known about annual plantations as sugar cane, soybeans, corn, but little information is available about some perennial plantations in the tropical areas. In this study we assess the influence of the banana plantation on macroinvertebrate communities in low-order streams in Southeastern Brazil. The samplings were carried out 10 streams in the State of São Paulo, of which, five located in areas of banana s culture and five in forested areas. In each stream, physical and chemical variables as well as concentrations of bioavailable metals in the sediment (Zn, Fe, Cr, Cu, Mn, Mg, Pb, Ni) were measured. Macroinvertebrates were simultaneously collected with both a D-net, and with Surber samplers. The concentrations of metals were higher in the sediment of streams in the banana plantations sites when compared with streams in forested areas. Of the 4427 aquatic macroinvertebrates collected, 61 families were found, 51 in forested streams and 49 in the banana plantation sites. Gripopterygidae, Perlidae, Leptophlebiidae, Leptoceridae, Helicopsychidae, and Palaemonidae were more abundant in forested streams, while Hydropsychidae, Chironomidae and Baetidae were more abundant in the streams in the banana plantations. Macroinvertebrate diversity, richness, and evenness indexes responded to land use characteristics; the most forested streams sustains the highest community diversity. NMDS ordination applied to the fauna data of all streams also evidenced the separation between forested streams and banana plantations streams. Mantel and partial Mantel tests indicated high correlation between the community structure and land uses and geographic distances. Therefore, this agricultural activity seems to influence the structure of macroinvertebrate communities in low order streams in the Atlantic Forest region.
Pós-modernidade e risco na bacia hidrográfica do Alto Paranapanema: uma análise da construção social da sub-política ambiental no município de Piraju (SP)
(Universidade Federal de São Carlos, 2007-08-31)
Cerveira Filho, José Luiz Fernandes
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Vargas, Marcelo Coutinho
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https://lattes.cnpq.br/0243387443214953
During the twenty century the hydroelectric industry was responsible for the most offers of energy in Brazil. However, recently hás been sharpen with one the biggest responsible for the environmental degradation enlargement. After diverses conspicuousness about environmental damages, the society began to reflect in more deeply way about there future and there mecanisms of technical development. The misfortunes systematic harvest in the environmental field brings the real possibility of social interference, by new institutions, as well others not so new, but reformulated, like some legal institutes of long tradition. If, in one hand, the legal institutional acknologment that suchlike activity degrades the environmental not guarantee that quelly measures can be catched, in the other hand, contributes expressively towards the development and the legitimation of new morals patthers of sociability. Is the moment that we qualify the pos modernity, when emerges the favourable conditions in order to social action, mainly in local level, where perceives and manages in concrete way the impremeditated consequences of the energy matrix development. The general objective of this study was apprehend what were the motivations for the municipality of Piraju (SP) elaborated and aproved one ensemble of restrictives measures to new hydroeletric activity. Specifically seeks to comprehend how the process of social construction of this reflective mark happens, and how the study of this construcionist process can corroborate with some comtemporary social theory. Secundarly tried to comprise the career of local environmental moviment and whereby variant of this interest, how some questions considers pos moderns collaborates for the local desconstruction by the developmentism of the hydoreletric sector.
Modelagem matemática do processo de secagem, por convecção forçada, de sistemas simuladores de alimentos esféricos e deformáveis
(Universidade Federal de São Carlos, 2007-09-05)
Arrieche, Leonardo da Silva
;
Sartori, Dermeval José Mazzini
A opção cooperativa: os trabalhadores diante da falta de alternativas de ocupação e renda
(Universidade Federal de São Carlos, 2007-09-09)
Mondadore, Ana Paula Carletto
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Lima, Jacob Carlos
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https://lattes.cnpq.br/9244132532446607
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https://lattes.cnpq.br/6285229833158202
From the 90 s decade, the economical, technological and organizational changes that characterized the process of productive restructuralization in Brazil had as a result deep transformations on the job market. In this context the work and production cooperatives resurge, perceived as a possible alternative of occupation for the workers. These cooperatives have caused an ample debate about their effective role and possibilities. On one hand, there are the defenders of the called Solidarity Economy, who see the cooperatives organization not only as an option of unemployment, but a chance, for the workers to perform a change inside the structures of capitalism. On the other hand, the cooperatives are perceived according to their functionality for the capital, being organized to attend the necessities of cost reduction at the companies through the elimination of the social benefits included in the wage relation. We investigated a cooperative that produces clothes, which works outsourced for a big company of the sector, to recover the workers perception about the self-managing work. We noticed that the option for the co-operative work reveals a lot of dimensions, from the economical choice, through the guarantee of job and high salaries to the characteristical autonomy of the self-managing enterprises, but the deep transformation in the relation between capital and work is far from effectively happen in the day-by-day totality of the cooperative work, mainly if we think about the relation between company and cooperative
Estratégia de produção: influências na gestão da estrutura e das relações de cadeia de suprimentos - caso no setor de linha branca
(Universidade Federal de São Carlos, 2007-09-10)
Sousa, Ana Beatriz Lopes de
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Alves Filho, Alceu Gomes
;
https://lattes.cnpq.br/7885557554922569
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https://lattes.cnpq.br/8088778385878104
This research aims to understand how white goods company s production strategy affects structural and relacional aspects of supply chain management, in specially those relatives of first tier suppliers. A reason for this research is the importance of understanding the dynamic of companies supply chain, constantly requested to serve all kinds of different markets. It couldn t be found a referential model to analyze this research, so a hypothesis is used: production strategy decisions influences the structure and relationship of supply chain management by execution of business process with suppliers. So, based on some aspects of production strategy and supply chain management literature, this research seeks to determine some elements capable of management tools to find out if that hypothesis is correct.The managemently elements are taken because they promote the integration of business process, bonding focal company and suppliers. This research is characterized by explorative and qualitative search and the way to get information is done through interviews with purchase and products development managers of focal company and production managers of suppliers companies. The main contribution of this research is to find out that production strategy s focal company influences the structure and relationship of supply chain management. This occur by conformation of managemently elements that allow cooperation of first tier suppliers, due to those stand the execution of business process of focal company.
Investigando geometria: aprendizagens de professoras da educação infantil
(Universidade Federal de São Carlos, 2007-09-10)
Lamonato, Maiza
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Passos, Cármen Lúcia Brancaglion
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https://lattes.cnpq.br/9619359782586567
The present work begins from the teaching experience of its researcher and in studies which identify the absence of geometry teaching in the education of children and youngsters; it is also based on data indicating the formation possibilities of mathematical investigation in the math teaching, and research specifically considering geometry as a privileged field for exploration and investigation. Its main objective was to investigate the teaching professional knowledge of four six-year-old pupil teachers and it chiefly focused on the moments when such teachers: got involved in geometry exploratory-investigative activities, discussed the teaching process in this math field, designed tasks to be implemented in the lessons, experienced the pedagogical process and meditated on it. Furthermore, it sought to investigate the formation possibilities of exploratory-investigative activities in the constitution and (re)significance of the teacher s knowledge and the possibilities for such activities to be in the lessons for six-year-olds through the actions developed by the participant teachers. This study counts on the qualitative approach and its theoretical fundamentals lie in the research on teacher s knowledge taking into consideration that learning to teach is a continuous process influenced by various aspects and in the works on exploratory-investigative activities in the math teaching. The empirical data stem from an in-service education course and consist of: researcher s diary notes, participant teachers notes, video recordings, and transcriptions of the recordings at the meetings in the course, where the researcher also acted as a trainer. The data analysis was then based on three facets: the importance geometry takes, exploratory-investigative activities and teacher s knowledge, the reconstruction of professional knowledge as to the reconsideration of the pedagogical praxis. The analysis confirmed that geometry is not a math field regularly present in the teachers school routine owing to their experience when at school as students and presently as teachers. During the participation of the teachers in the activities designed for them to learn geometry in the context of exploratory-investigative math, an initial feeling of estrangement arose towards open-ended tasks, progressed by a questioning and argumentative attitude. It also came to light some elements related to the importance of the tasks in the development of the activity. The reconsideration of the pedagogical practice as a result of the activities experienced and the moments of sharing reflections gave birth to the development of new viewpoints as to how geometry is conceived at the outset of primary school, being beyond geometric patterns and encompassing spatial notions and spatial representations. Moreover, such reconsideration resulted in new elaborations of the pedagogical content knowledge, which indicates possibilities for mathematical exploration-investigation in the math teaching for six-year-olds. It also showed changes in the teachers attitude when adopting a questioning and investigative posture, which would, in turn, take children to question and justify their hypothesis in an integrated activity with their teacher. The actions developed by the participant teachers in the classroom confirmed such possibilities, and brought new perspectives to understand the purpose in the children s writing and attitudes when playing in the room.
Complexos de cobre(II) e oxovanádio(IV) com bases de Schiff Quirais: preparação, caracterização e alguns ensaios catalíticos
(Universidade Federal de São Carlos, 2007-09-11)
Romera, Sandra
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Dockal, Edward Ralph
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https://lattes.cnpq.br/6461328124491559
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https://lattes.cnpq.br/2218901978475504
Salen complexes are an important class of coordination compounds, which have been used to catalyze a wide variety of reactions. The salen complexes have emerged as efficient and practical catalysts for the asymmetric oxidation of various organic substrates. In this thesis, copper(II) and oxovanadium(IV) complexes of the salcn type ligand [salcn= N, N -bis- (salicylidene)-1,2-cyclohexanediamine] have been investigated as catalysts for oxidation of organic sulfide. The first part of this work describes the synthesis and characterization of the free ligands and copper(II) and oxovanadium(IV) complexes. The combination of four complementary techniques (IR, UV-vis, 1HNMR-13CNMR and X-ray) made possible the characterization of the free ligands and complexes. Six unpublished crystallographic structures were determined: four ligands and two oxovanadium(IV) complexes . In the second part of this research were studied catalytic properties of some complexes in oxidation of phenyl methyl sulfide using acetonitrile as the solvent and hydrogen peroxide and t-butylperoxide as the oxidant. The [Cu(salcn)] and [VO(salcn)] with electrons donors and electrons withdrawing substituents were tested for catalytic oxidation. The effect of reaction conditions on activity with various oxidants gave distinctly different yields. The complex trans-(±)-[Cu(5- Clsalcn) showed the best result, with 73% of the sulfide conversion. This is result was showed with hydrogen peroxide as the oxidant. The yields obtained for the other compounds vary of 11-32%.
A influência do material didático na motivação de aprendizes da língua inglesa em contexto de ensino público
(Universidade Federal de São Carlos, 2007-09-12)
Campos-Gonella, Cristiane Oliveira
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Augusto-Navarro, Eliane Hercules
;
https://lattes.cnpq.br/5716027350340906
The aim of this work is to verify the motivation of students to study English in the beginning of their first year right after primary school (5Th grade in Brazil), as well as to analyze the influence of teaching materials adopted in the students motivational disposition. We have confirmed, through our analyses, the hypothesis that students are motivated in the beginning of the foreign language teaching and learning process and, based on authors such as Augusto-Navarro (2007), Barbirato (2005), Stipek (2002), Dörnyei (2001), Peacock (1997), Pintrich e Schunk (1996), Almeida Filho (1994), Viana (1990), Krashen e Terrell (1983), and others, we discuss some characteristics, which if guaranteed in the teaching material, may help the teacher to maintain students motivation. This study may contribute for a better comprehension of the frequent demotivation process observed among English language students in Brazilian public schools. It also presents the characteristics of highly motivating, as well as demotivating, EFL teaching activities.
Caracterização ótica de poços quânticos de GaMnAs
(Universidade Federal de São Carlos, 2007-09-12)
Holgado, Danny Pilar Araucano
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Gobato, Yara Galvão
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https://lattes.cnpq.br/7558531056409406
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https://lattes.cnpq.br/2035102451161467
In this work, we have studied GaAs/AlAs/Ga1-xMnxAs quantum wells (QWs) with low Mn concentration ( 0 < x < 0,2%). The samples were grown by Molecular Beam Epitaxy (MBE) in high temperature (450 C). The growth conditions were chosen to reduce the incorporation of As and interstitial Mn resulting in samples of good optical quality. We have studied samples growth in (311B) and (001) GaAs substrates with different manganese concentrations, x = 0.0%, 0.07%; 0.1%;. We have performed measurements of polarized resolved photoluminescence for magnetic field up to 15T in Faraday configuration. We determined the degree of circular polarization and the excitonic spin-splitting for the QW emission as function of magnetic field.
Refratários para o transporte de alumínio líquido: fundamentos, simulação e prática industrial
(Universidade Federal de São Carlos, 2007-09-13)
Miyaji, Dan Yushin
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Pandolfelli, Victor Carlos
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https://lattes.cnpq.br/7369376873984839
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https://lattes.cnpq.br/4150977564959773
Not only for the development of their products, the aluminum industry has engaged its efforts in services for their customers. One of them is the molten aluminum delivery (7 to 8 t) in crucibles for long distances (over 100 to 200 km). This is an advantageous practice for the customers because it allows saving energy in the melting process, and the suppliers can add value to the metal purchased. Because the process demands great amount of molten metal, a high thermal and mechanical performance of the crucible lining is needed. Thus, a systemic analysis involving design, thermodynamic, microstructure, thermal conductivity and thermo-mechanical aspects must be considered. This work aims to match these fundaments, the industrial results, the laboratory characterization of materials and the computing simulations using a software recently developed by the working team. This software is able to predict the thermal behavior of the heated containers even under operation. Therefore, based on the three pillars named theory , simulation and industrial results a new commercial refractory lining were selected improving the net volume of the crucible and saving the energy required for its pre-heating. As a second step of the resent work, one of main weak points of this refractory, the erosion resistance, was minimized
Desenvolvimento de nanocamadas e nanocristais de Óxido de Zircônio aplicados a catálise
(Universidade Federal de São Carlos, 2007-09-14)
Santos, Valdemir dos
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Leite, Edson Roberto
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https://lattes.cnpq.br/1025598529469393
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https://lattes.cnpq.br/1070760903014158
This work investigate the synthesis and characterization of a catalytic support of -alumina with a nanolayers and nanocrystals of ZrO2. The incorporation of the platinum began during and after the formation of the catalytic support. The technology is based on the Pechini method. The nanolayer was applied to cover the surface of the γ-alumina, avoiding a direct contact with the active phase (Pt). The structural and morphologic properties of these materials were analyzed through X ray diffraction, high resolution transmission electronic microscopy and zeta potential among anothers. It is found that surface reaction of alumina with zirconium (polimeric resin) leads to high dispersion of Zr. Degree of dispersion depends on several parameters such as heating treatment , zirconia cotent. Zirconia on alumina is atomically dispersed and forms only one phase in the range 10-25 wt% ZrO2. After this concentration level of ZrO2 crystallite are formed. Was observed that Pt present on catalytic support maintain high disperssion degree, this feature is independent of route used. The data analysis suggest that catalytic surface properties are different. Therefore, a particular catalytic behavior for these catalysts are expected.