Browsing by Issue Date, starting with "2010-09-30"

Filter results by year or month

Now showing 1 - 20 of 20103

Comportamento de variedades de cana-de-açúcar (Saccharum spp.) em inoculações com diferentes concentrações de Leifsonia xyli subsp. xyli
(Universidade Federal de São Carlos, 2010-09-30)
Brumatti, Catiana Regina
;
Vieira, Marcos Antonio Sanches
;
https://lattes.cnpq.br/7031724562598209
;
https://lattes.cnpq.br/2447176138980567
The sugar cane is a semiperennial plant currently considered one of the most important crops in the world due to its ability to produce renewable energy (ethanol) and sugar. The soil quality, water availability and temperature are the main effects that made Brazil the largest producer. However some factors influence the sugarcane productivity, mainly diseases. Among them we can cite the ratoon stunting disease caused by the bacteria Leifsonia xyli subsp. xyli worldwide known to cause up-to-30% losses in the productivity. The spread of infected seedlings and the absence of external symptoms make it difficult to diagnose and require the use of laboratory techniques. Thermotherapy, cutting-material cleaning with detergent solutions and the use of resistant varieties are the key measures to contain the disease. Due to its easy spread and high rates of reduction in the productivity the objective of this study was to evaluate how the effect of four different concentrations of Lxx for four cuts, would affect the interaction varieties x cuts x bacterial concentration. Therefore it evaluates possible losses on the technological variants and the reliability of Dot blot test for the PCR from DNA extraction according to the protocol of CTAB. The analyzed data showed no significant reduction in varieties productivity in none of the four different bacterial concentrations including the control plants, as well as in technological variables on study. According to data the Dot blot technique was more sensitive than the PCR conditions utilized in this study.
Prematuridade e baixo peso em pré-escolares: fatores de risco ao desenvolvimento da linguagem e alterações fonológico-lexicais
(Universidade Federal de São Carlos, 2010-09-30)
Iemma, Elisa Pinhata
;
Martinez, Claudia Maria Simões
;
https://lattes.cnpq.br/0357988408477189
The expressive number of premature births shows the necessity of measures focused in preventing disorders in these children development. Literature reveals that language is one of the areas that may be affected when the child is exposed to risk factors. Considering language as the predictor of academic intelligence and skills, it becomes relevant to study the phonological and lexical aspects of preschool children with historical of prematurity and low birth weight. Supposedly, these children may present faults in this repertory in the moments that precede their formal schooling. This research received the approval of the Ethics Committee of the Federal University of São Carlos. It reports a descriptive study which aimed to detect language alterations/disorders in preterm born children with low weight which go to preschool. The following instruments were used to collect data: Critério de Classificação Econômica Brasil (2008); maternity house medical records, Screening Test Development Denver II (TSDD-II) and ABFW test. The participants in this study were 19 children between 3 and 5 years-old with historical of prematurity and low weight that required neonatal ICU after birth and are enrolled in the Public System of Child Education (Municipal Kindergarten). The results present, initially, the profile of the study sample with data from the children clinical history and their socio economic situation. The results yet reveal that in the Denver Test (TSDD-II), language was, among four other areas, the most affected. In this situation, 9 of the 19 children under evaluation have presented risk. Regarding the ABFW test performance, it is stressed that all the participants have presented risks. Regarding the phonological aspects, 8 children have presented an altered performance in the phonologic test. All the participants presented vocabulary deficiency. By analyzing language, 5 of the 19 children had faults in the phonologic areas of ABFW and of vocabulary, as well as the presence of risk in the language area in TSDD-II. The importance of the evaluation procedures and the language development accompaniment of this population in the moments that precede litaracy as preventive measures is being largely discussed, as well as the contributions of the ABFW test as an instrument that allows not only to situate the deficits but also, based on these deficits, to elaborate strategies of intervention for parents and teachers. The data related to clinical history and socio economic level were used to make interpretations of the similarities and differences in the scores found in both instruments from the concepts of risk, protection and resilience. The small number of participants can be pointed out as a limitating factor of this paper. For future studies it is suggested the conduct of follow-up and the development of intervention programs directed to parents and teachers in the perspective to prevent or minimize communicative deficits.
Reconhecimento de padrões de imagens de traços nucleares produzidos por partículas alfa em detectores de estado sólido
(Universidade Federal de São Carlos, 2010-09-30)
Trindade, Ananda Coaglia
;
Cruvinel, Paulo Estevão
;
https://lattes.cnpq.br/7924553462118511
;
https://lattes.cnpq.br/8774079177150720
This work presents a new technique for image analysis generated by alpha particles in solid state nuclear track detectors using Hough Transform to identify complete standards and Artificial Neural Networks which act as classifiers of incomplete standards. Radon, during their decay process emits alpha particles that may be registered in detector of certain materials as inorganic crystals, plastic or glass. Through these detectors is possible to obtain images generated by alpha particles and therefore calculate the concentration of radon in an environment. Radon and its decay products contribute to the majority of ionizing radiation received by worldwide population, particularly in indoor environments. Studies carried out over the years confirmed the association between radon exposure and lung cancer. Considering the importance of studies related to radon, the need arises to explore the existing techniques to obtain the concentration of radon indoors and create new techniques that are better adapted to current needs.
Compreendendo os fenômenos nucleares, suas aplicações e implicações através de uma atividade lúdica
(Universidade Federal de São Carlos, 2010-10-01)
Martins, Gisela Garcia
;
Marques, Rosebelly Nunes
;
https://lattes.cnpq.br/7921735904003583
It has been shown that students of latest high school year do not know the meaning of the symbols of radioactivity, and sometimes they mix up mentally with different sources of radioactivity or types of radiation. Students usually link radioactivity with nuclear weapons or with nuclear accidents that they have heard about. Important issues of radioisotopes such as the applications in medicine are unknown by students and seem to be far off student everyday life. Didactic and playful materials are recognized as important tools to help teachers to motivate students in many activities. In this work we have developed a didactic game for Chemistry and Physics students based on game approaches and new teaching/learning methods. The material proposed here consists in a ruleassisted didactic game, a board game with cards and dice that requires from the players the knowledge and reasoning in radioisotopes and nuclear phenomena to answer the proposed questions in order to get forward. This didactic game was tested in classroom and the results indicated an increase of student s interest and skills in the subject.
Estado e sociedade civil na cooperação internacional: perspectivas dos países doadores, receptores e do Brasil
(Universidade Federal de São Carlos, 2010-10-07)
Leonardi, Ramon Santoro
;
Nogueira, Marco Aurélio
;
https://lattes.cnpq.br/2644317935020891
;
https://lattes.cnpq.br/0836126420407810
This essay is on the relationship between State and civil society, through the angle of international cooperation. The work has two parts. The first studies the concept of civil society, on its multiple meanings through modern period and its possible contemporary instances as political project. The second inquires the international cooperation relationships between donor and receptor countries, considering different actor perspectives. The analysis focus on years between 2002-2008, and a part of the explanation details Brazil case. Moreover, this study aims to contribute on the globalization debate, mainly on its effects over power framework and world order.
Processo para gerenciar a integração de clientes no processo de desenvolvimento do produto
(Universidade Federal de São Carlos, 2010-10-07)
González, Mario Orestes Aguirre
;
Toledo, José Carlos de
;
https://lattes.cnpq.br/9421627326330417
;
https://lattes.cnpq.br/5936291138113637
Understanding customer needs is considered, in the literature of management product development process, one of the major critical success factors of a new product. However, current researches highlight those traditional methods for lifting these needs show deficiency, especially those latent needs. It has emerged, therefore, theories that seek to improve this situation as: product development focused on the client, principles of ethnography applied to product development process and user innovation. In the latter, the client is considered as having skills not only of knowledge about market needs, but also with technological domain by experience in product use and ability to generate ideas and new applications for new products. Based on these precedings the research proposal on the integration of customers in product development process appeared. This thesis aims at proposing a process for managing the customer‟s integration in the product development process in companies of capital goods. The subsidies for elaborating the proposal derived from a literature review and field research, which included case studies in five companies. The process for the customer integration is composed of three macrophases and six phases. Each phase involves activities, specific tasks and use of techniques and tools to support realization of activities. The macrophase of Customer Integration on Pre-Development involves the phases: Prospection of customer needs and/ or market opportunities, selection of clients for the Pre-Development and integration of customers on idea generation and/ or business opportunities. The macrophase of Customer Integration on Development involves the stages: Selection of clients for his integration in the product development and Customer Integration in the product development. The macrophase of Customer Integration on the Post-Development has as phase the evaluation of the customers integration in the product development. The results of the thesis contribute to both the theoretical knowledge on the subject and the practice of companies. From the theoretical point of view, the proposed process brings together content from various subject areas, analyzes and synthesizes, following the guiding principle of customers integration in product development process. From a practical standpoint, the proposed process assists in the organization and operationalization of customers integration activities, particularly in capital goods companies.
Comparação do desempenho de Modelos Lineares Generalizados (MLG) e Modelos Aditivos Generalizados (MAG) na predição de dados ﬁnanceiros em credit score
(Universidade Federal de São Carlos, 2010-10-07)
Guirado, Lorene
;
Perdoná, Gleici da Silva Castro
;
https://lattes.cnpq.br/0745160064860746
;
Louzada Neto, Francisco
;
https://lattes.cnpq.br/0994050156415890
This study aimed to present and compare the performance of two different methodologies for statistical modeling of ﬁnancial data with dichotomous response, speciﬁcally exempliﬁed by models of credit score as well as methodologies for validation and performance analysis of these models. One of the measures used in this analysis is the lift, often used in marketing, but little used in the ﬁnancial area, this measure is also used as a descriptive technique for categorizing variables. The techniques presented here are the Generalized Linear Models (GLM), the most usual method, and Generalized Additive Models (GAM), unusual in ﬁnance because it is a semi-parametric or nonparametric model, generating even some diﬃculty in interpretation because it does not present parameters. The predictive capabilities of the two techniques are compared in an application on real data and in a simulation study.
Diretrizes para um sistema de medição de desempenho para empresas do ramo madeireiro da região amazônica norte mato-grossense : estudo multicasos
(Universidade Federal de São Carlos, 2010-10-07)
Fedato, Geovana Alves de Lima
;
Martins, Roberto Antonio
;
https://lattes.cnpq.br/3518820028045730
;
https://lattes.cnpq.br/1986334535430468
This work assumes that to effectively manage business activities, a form of control and monitoring is necessary, whether by means of indicators, or in a more advanced situation, by means of a performance measurement process that is suitable to the company s reality. Thus, the objective of this study is to establish guidelines for develop a performance measurement system, capable of assisting the peculiarities and organizational needs of control and strategies for companies in the wood sector in the city of Sinop, in Mato Grosso, Brazil. Companies currently face several challenges, because they need to thrive in a highly competitive environment, concomitantly meeting the needs and expectations of multiple stakeholders. This paper addresses the importance of environmental and social variables, which are currently increasing and whose reflexes on the organization are no longer latent but obvious. The method used to achieve the goals was the multiple case study with a qualitative approach, which enabled to identify the companies selected, and from this reality, to establish guidelines for develop a performance measurement system for two scenarios, was first proposed for the method of Rouse e Putterill (2003) for companies without an adequate infrastructure to measure performance. The second applies the Performance Prism framework by Neely et al. (2002) for companies with more suitable infrastructure for the development of a system performance measurement more robust. In all the companies of the scenario, social and environmental issues can be included, hence representing the reality under study in a clearer manner. The contribution the academy is conducted to compare the characteristics of performance measurement and management infrastructure, already contributing to the logging companies was made to suggest ways to control and evaluation of activities that respect the maturity of the management and peculiarities of each.
Expansão de células-tronco mesenquimais em frasco spinner com microcarregadores
(Universidade Federal de São Carlos, 2010-10-07)
Sanches, Simone
;
Suazo, Cláudio Alberto Torres
;
https://lattes.cnpq.br/9591447226240450
;
https://lattes.cnpq.br/3642437679422467
The Mesenchymal Stem Cells (MSCs) from adult tissues are at present an attractive source for applications in tissue engineering and cellular therapies. It presents a potential to differentiate into different cell lines as adipocytes, chondrocytes, osteocytes and myocytes. Due to low availability in the tissues and the fact that the demand for therapeutic applications is much larger than the supply capacity has become necessary to expand them in vitro strongly dependent on conservation of their differentiation potential. The MSCs are anchorage dependent, they have the characteristic of adhering to a solid substrate for subsequent proliferation. The conventional procedure of expansion in T-flasks with growth in monolayers, usually involves a difficult monitoring and control process, with high contamination indexi, low cell yield and high cost. In this work, we evaluated a methodology of expansion of hMSC-TERT line in spinner flask with microcarriers (small particles with properties favorable for cell adhesion and proliferation). In the experiments, two type of microcarriers were used, Cytodex 1 non-porous and with positive electric charge and Cultispher S, macroporous and electrically neutral, both in stirred spinner flask of 100 mL in culture medium α-MEM with 15% fetal calf serum, maintained in a CO2 incubator at 37°C and pH between 7.2 and 7.4. To increase productivity, some strategies were adopted during the research as a nutritional balance of the culture medium, addition of microcarriers and dilution and/or replacement of medium during cultivation. Aided by analysis of metabolites by high performance liquid chromatography and optical microscopy, the results showed that it was possible to grow hMSC-TERT with two microcarriers while maintaining good conditions for growth in three dimensions. However, the cell yield was limited mainly by the formation of clusters of microcarriers/extracellular matrix and is possible to obtain a cellular expansion factor of 4.98 with Cytodex 1 and 9,70 with Cultispher S. Because of the easy recovery of the cell showed by later microcarrier, it was performed an analysis of the maintenance of antigenic phenotype by flow cytometry and induction of differentiation into adipocytes and osteocytes. The results confirmed the conversation of phenotypic characteristics of hMSC-TERT with the cultivation technique evaluated in this work.
Análise dos constituintes fixos e voláteis de fungos endofíticos dos gêneros Penicillium e Xylaria e de suas plantas hospedeiras
(Universidade Federal de São Carlos, 2010-10-08)
Santos Filho, Florisvaldo Clementino
;
Rodrigues Filho, Edson
;
https://lattes.cnpq.br/3667941735597178
;
https://lattes.cnpq.br/6033248350460741
Was conducted the study of chemical constituents volatiles and fixed of endophytes fungi. For this, we used the Penicillium griseoroseum, Penicillium brasilianum, Xylaria (NICL3) and different species of the genus Trichoderma, was also carried out a study of host plants, such as Cupressus lusitanica and Melia azedarach. Through analysis by GC-MS and methodologies for calculations of retention indices were identified monoterpenes, sesquiterpenes and diterpenes in the oils of plant and fungus. Compounds similar to essential oils of plants and associated microorganisms led to believe in the existence of biochemical interactions. Transesterification acid reactions was used for extraction of lipid compounds that were identified, characterized and quantified by techniques GC-MS, ¹H NMR and GC-FID. Profiles of methyl esters of fatty acids were found varied according to the species used, leading to mounting a chemo-taxonomic classification. Data quantification according to EN 14 103 showed that two endophytic fungi can be considered a promising source of biofuels. Antifungal assays of essential oil of Cupressus lusitanica were performed against endophytes be showing the importance of volatile compounds in the plant-endophytic microorganism.
Efeitos do chumbo sobre o desenvolvimento do tecido ósseo de ratas
(Universidade Federal de São Carlos, 2010-10-08)
Mattos, Valéria Gonçalves Albieri
;
Nonaka, Keico Okino
;
https://lattes.cnpq.br/4551036775738296
The aim of this study was to investigate the effects of lead on femurs and vertebrae during development and skeletal maturity of female rats. For this purpose, one month old female rats were treated with lead acetate 100mg/kg BW or saline 0,9% 0,1ml/100g BW . The treatment was administrated by gastric gavage, once a week, during two months. After the treatment period, the animals received only tap water and commercial chow ad libitum until they completed 6, 9 and 12 months of life. The 3 months old groups were sacrificed soon after the treatment. The incorporation of lead in bone tissue occurred in all groups of intoxicated animals. The lead did not interfere the body development of experimental animals. The lead intoxication induced reduced maximum load, stiffness and resilience of the femur in the threepoint bending test in the groups 6, 9 and 12 months of life. The compression test of vertebrae of contaminated rats showed reduction of biomechanical parameters only in skeletally mature rats (9 months). The present study revealed that lead exposure during early stage of development affected the bone mineral profile leading to biomechanical weakness with skeletal maturity. The results allow us to conclude that lead exposure affects the biomechanical properties of mature bone increasing susceptibility to fractures.
Convergência de elites: a sustentabilidade no mercado financeiro
(Universidade Federal de São Carlos, 2010-10-08)
Sartore, Marina de Souza
;
Grün, Roberto
;
https://lattes.cnpq.br/6028266827740491
;
https://lattes.cnpq.br/7935836189977378
The launch of the Brazilian Corporate Sustainability Index in Sao Paulo s Stock Market, analyzed through an economic approach, can be reduced to a new financial tool which measures the profitability of Sustainable listed companies. However, through a sociological approach, the launch of this index is equivalent to the creation of the Brazilian Socially Responsible Investment Market. The creation of this market demonstrates the emergence of new polarizations in the Economic Field, particularly in the Financial Field. These new polarizations indicate a change in the Financial Field, which presents a new way of thinking the Financial Market based on taking account of social, environmental and financial criteria. This change emerges from an elite convergence which challenges the limits of the Financial Field, at the same time trying to reinvent the Financial Market through a proposal of a Sustainable Capitalism. This thesis indicates that it s possible to understand the creation of Socially Responsible Investment Market by studying the actors and institutions that participate in the Corporate Sustainability Index s Committee. As a result, this study emphasizes the urge of developing a Sociology of Indexes. At last, this thesis concludes that the Sustainability insertion in the Financial Field is legitimated by a group acting in the financial area, which converges with the Corporate Social Responsibility s and The Environmental Movement s elite, in an attempt to turn the table of mainstream finance. However, this mainstream turn does not push towards the ending of financial market, but it s strengthening instead.
Determinação simultânea de íons metálicos utilizando voltametria de redissolução anódica e métodos de calibração multivariada
(Universidade Federal de São Carlos, 2010-10-14)
Marreto, Paola Daniele
;
Faria, Ronaldo Censi
;
https://lattes.cnpq.br/8659496864305621
;
https://lattes.cnpq.br/3608366417250207
This work describes the determination of Cu2+, Cd2+, Pb2+, Zn2+ and Co2+ using electroanalytical techniques and analyzing the data with chemometric tools. First, an univariate approach was used to investigate RMSEParately each ion using anodic stripping voltammetry in two different concentration range, mg L-1 and μg L-1. Then, the voltammetric profiles were measured for the mixture to check for interaction among them. In a second step, an orthogonal array with 16 experiments was used a calibration matrix and a second one with 10 samples as validation group. Then the profiles were mean centered and the PLS algorithm with different kind or data transformation were used to calculated both the cross validation and external validation. To improve the results KS and SPXY methods were also used. PLS results were the best method for the cross calibration detection but such procedure leaded only to correct measuring of 3 different ions. Following, the SPA method were used together with KS and SPXY and results shown the correct determination of 4 ions with external validation. A further improvement of the results were obtained when the SPA procedure were used together with MLR method to select the variables (potentials, in the present case). In this case, the prediction capacity increased and also the effect of variables selection and its correlation with the formation of intermetallic compounds were evaluated.
Aproveitamento do caroço do açaí como substrato para a produção de enzimas por fermentação em estado sólido
(Universidade Federal de São Carlos, 2010-10-14)
Santos, Rodrigo Rafael Mendonça dos
;
Pessoa, José Dalton Cruz
;
https://lattes.cnpq.br/4212703554284544
;
https://lattes.cnpq.br/5649914970078519
The açaí agroindustry is the most important productive chains in northern Brazil. The residues in the marketing of açaí consists mainly of its pits, which are discarded in landfills and waterways without any treatment. A possible application to açaí pits is its use as substrate for solid state fermentation (SSF) for the production of lignocellulolytic enzymes as CMCase and xylanase, which act in the conversion of lignocellulosic materials into fermentable sugars. Currently, the cost of production of these enzymes has emerged as the biggest obstacle to the use of agro-industrial waste and the process of SSF gained prominence in this context due to several advantages over other technologies. The SSF process presents a large number of variables that affect the production of metabolites of interest, highlighting the sources of carbon and nitrogen, inducing growth and mineral salts. This study aimed to evaluate the use of pits of açaí as substrate for enzyme production by SSF evaluating the influence of the composition of culture medium for SSF through application of the methodology of statistical design full factorial 24 for selection of significant variables. The variables studied were the initial medium moisture and the concentrations of meat peptone extract, yeast extract, and CMC. After extraction of the enzyme complex and quantification of CMCase and xylanase activities, the variables of concentration of meat peptone extract and yeast extract were significant for enzyme production. Subsequently, a central composite rotatable design (CCRD) was made to achieve the optimization of the process parameters. The highest activities were obtained by increasing the concentration of meat peptone extract and yeast extract, reaching 8.24 U g-1 and 8.08 U g-1, to CMCase and xylanase, values, respectively. Additional tests were made at concentrations three times higher than those used at the midpoint of the CCRD, which indicated an increase of 1.59 and 1.16 times in the enzymatic activities of CMCase and xylanase, respectively. However, by Tukey test, these increases did not differ statistically in comparison to the tests results obtained using concentrations of reagents encoded at +1.41, giving economic advantage to the tests made with smaller amounts of reagents. The pit of açai has shown promising as a substrate for SSF, but additional studies are performed to define and optimize the process parameters.
Estudos cinéticos e fotoquímicos de compostos de Ru(II) com ligantes bipiridínicos e bifosfínicos de fórmula geral cis- [RuCl2(P-P)(N-N)] (P-P = bifosfinas e N-N N-heterocíclicos bidentados)
(Universidade Federal de São Carlos, 2010-10-14)
Nascimento, Fábio Batista do
;
Batista, Alzir Azevedo
;
https://lattes.cnpq.br/6469642481998660
;
https://lattes.cnpq.br/8022643415351039
In this thesis it were studied substitution reactions in ruthenium complexes of the type cis-[RuCl2(P-P)(N-N)] and cis-[RuCl2(dppb)(N-O)] (P-P = dppm, dppe, dppp and dppb; N-N = bipy, Me-bipy, MeO-bipy, Cl-bipy and fen; N-O = 2-acpy, 2-bzpy and 2- dpk). For all complexes, in a period of 24 hours, there was only the substitution of a chloride (Cl-) coordinated to the metal. The ligands used in substitution reactions and kinetic studies were: py, 4-pic and coordenant solvents (CH3CN and PhCN). Only the Cl- trans positioned to P of diphosphines was labilized giving rise to the entering ligand, confirming the greater trans effect of phosphine ligands in relation to N-N and N-O. The mechanism attributed to substitution reactions was dissociative because the reactions do not show dependence of ligand entry. DFT calculations showed the effective participation of the Cl atom trans to the P atom of the diphosphines in the formation of the HOMO orbital. This fact shows that the reactivity of Cl atoms is different and they can be replaced selectively. Good linearity was observed for the percentage of participation of d orbitals of ruthenium in the formation of HOMO for the dissociation of Cl- complex indicating that the strength of the Ru-Cl- bond is due to the direct interaction of the orbitals of Cl- and the d orbitals of ruthenium. Exploratory studies using irradiation of light at fixed wavelengths were performed to study possible influence of the effect of the exchange rate of Cl- and also on the isomerization reaction trans/cis-[RuCl2(dppb)(bipy)]. An increase in the rate of exchange reaction was observed in the kinetics of substitution. In the isomerization processes were not observed. The substitution reactions of Cl- in the complexes cis- [RuCl2(dppb)(N-N)] (N-N = bipy and phen) by nitrile ligands (e.g. PhCN and CH3CN), lead to the formation of complexes in which trans ligands L were coordinated by the nitrogen atom of the ligands N-N in the final complex. However, studies of 31P{1H} NMR and cyclic voltammetry confirmed that the reactions take place initially with the replacement of L trans to P atom followed by an isomerization process. This is attributed to the strong competition of π between nitrile and phosphine ligands, and its final position is determined by this effect.
Sinterização, cristalização, desenvolvimento e caracterização de vitrocerâmicas de baixo coeficiente de expansão térmica do sistema Li2O - Al2O3 SiO2 (LAS)
(Universidade Federal de São Carlos, 2010-10-15)
Soares, Viviane Oliveira
;
Zanotto, Edgar Dutra
;
https://lattes.cnpq.br/1055167132036400
;
https://lattes.cnpq.br/3453493533943934
Glass-ceramics based on the Li2O-Al2O3-SiO2 (LAS) system represent the most important (commercial) family. They are required for applications where extreme dimensional stability and thermal shock resistance are of utmost importance. Glass-ceramics are mainly produced by the traditional method of melting and shaping followed by internal crystallization induced by nucleating agents and thermal treatments. In this work an alternative route to obtain glassceramics in the LAS system was developed by sintering with concurrent crystallization. Very low thermal expansion coefficient (TEC), good mechanical strength and nil porosity were the intended properties. Several glass compositions in this system were formulated and evaluated. The samples were characterized by optical and electrical microscopy, X-ray diffraction and dilatometry. The optimized glass-ceramic composition presented 1.4% of residual pore fraction and thermal expansion coefficient of 0.02 x 10-6 ºC-1 between 40C and 500C. The Clusters model was used to simulate its sintering process and good agreement with experimental data was achieved. Excellent thermal shock resistance up to 600C and a flexural strength similar to that of the commercial glass-ceramic Ceranwere obtained. In order to minimize the residual porosity and improve the superficial properties of the sintered LAS glass-ceramic, silica and silica/zirconia coatings obtained by solgel route were deposited by dip coating on the glass-ceramic surface. The silica/zirconia coating (TMZ), which was only 0,4 m thick, was the hardest one and exhibited the highest wear resistance. The sintered glass-ceramic here developed showed similar dimensional stability and mechanical properties to the commercial material Ceran, which indicate its potential application, for example, as cook top panels. viii
Estudo teórico e experimental da interação de elétrons com moléculas poliatômicas
(Universidade Federal de São Carlos, 2010-10-15)
Souza, Gabriel Luiz Cruz de
;
Tao, Lee Mu
;
https://lattes.cnpq.br/5112032594921811
;
https://lattes.cnpq.br/2821352329397835
In this work, we present an improvement on theoretical study of electron scattering by medium-size molecules at intermediate incident energy range, lying from the ionization threshold to 1 keV. More specifically, the absorption effects which represent the influence of inelastic scattering channels on the elastic channel were accounted for via the Padé Approximant technique. Modifications were introduced in the EPolyScat-D computational code, developed originally by Lucchese and co-workers in order to include such effects. The modified code was applied to calculate differential (DCS), integral (ICS), momentum transfer (MTCS), total (TCS) and total absorption (TACS) cross for electron collision with mediumsize hydrocarbon molecules, namely, ethane (C2H6), propane (C3H8) and benzene (C6H6) in the low- and intermediate energies. Our theoretical results were compared with the experimental data measured in Laboratório de Espalhamento de Elétrons DQ UFSCar and with the existing theoretical and /or experimental data. The good agreement seen in such comparison shows the effectiveness of our method. The extension of the applicability of the present code in order to investigate also electron scattering by polar molecules is now underway. Additionally, an experimental part of the present work consists of the measurement of absolute DCS for electron scattering with sulphur dioxide molecule (SO2) in the 100 1000 eV energy range. Our DCS were compared with the existing theoretical and/or measured data reported by others research groups and showed good agreement.
O silêncio dos aprendizes: um estudo sobre o "período silencioso prolongado" de aprendizes de língua estrangeira (inglês)
(Universidade Federal de São Carlos, 2010-10-19)
Toledo, Fabiano Bernardes de
;
Viana, Nelson
;
https://lattes.cnpq.br/6252579012192711
;
https://lattes.cnpq.br/2488246391118032
The aim of this work was to investigate factors that could be related to the silence (in the classroom) of students of English as a foreign language at advanced levels of study, a phenomenon that we will call prolonged silence period, based on Krashen‟s silent period concept. According to this concept, it is natural that students at the beginning of the learning process of a new language go through a period in which they remain silent, just receiving linguistic input, until they have acquired some knowledge and the necessary confidence to start talking. Some students, however, tend to remain silent in class, even at higher levels of language study. In this investigation, we focus on how these students act in class. This work is based on studies about affective factors involved in the language teaching and learning process carried out by Brown (2000), Almeida Filho (1993) and Krashen & Terrell (1998), on studies about students beliefs regarding this process, carried out by Vieira-Abrahão and Barcelos (2006), Barcelos (2001) and Almeida Filho (1993), among others. The methodology of the research involves interviews, field notes, questionnaires, student´s retrospective selfevaluation, and audio and video recordings with students from two intermediateadvanced level groups and three advanced level groups of a private language institute. The goal is to identify and discuss possible factors that contribute to the lack of oral participation of these students in class, as well as their beliefs regarding the foreign language teaching and learning process, especially as it is related to oral practice. Through this work we verified, for example, the existence of a belief according to which being at an advanced level of learning of the target language means not being allowed to make mistakes, due to the thought that at this level of studies the oral production must be free from errors. Consequently, to avoid making such errors, some students opt to remain silent in class.
Estudantes moçambicanos em Belo Horizonte: uma discussão sobre a construção identitária e de redes de sociabilidade
(Universidade Federal de São Carlos, 2010-10-20)
Ngomane, Yara Neusa
;
Machado, Igor José de Renó
;
https://lattes.cnpq.br/4705450652848752
;
https://lattes.cnpq.br/7234441229568980
The paper shows how identity processes are built for Mozambican students established in Belo Horizonte - arriving through agreements between governments and higher institutions of both countries - and how are woven their social networks. To this end, these students were observed as they related to each other, with Brazilians and Africans of other nationalities in their daily life. Through the fieldwork was noted in this migration, family networks and kinship being re-built. Likewise, through stories of prejudice and exoticism about the way of being and living of these individuals, their phenotype and behavior, it was perceived as ethnic and race relations were taking place and these students were transformed into Brazilian territory. Thus, throughout the dissertation refers to the concepts of ethnicity, race, nationality, kinship and social networks because they are interwoven to show a better understanding of the presence of Mozambican students in Brazil.
Uso de "ecotécnicas" no manejo de águas pluviais em meio urbano: uma abordagem crítica
(Universidade Federal de São Carlos, 2010-10-21)
Silva, Eduardo Araujo
;
Silva, Ricardo Siloto da
;
https://lattes.cnpq.br/5346985934880710
;
https://lattes.cnpq.br/5330738759062637
The environmental situation of the cities, especially the larger ones, presents serious problems arising from human's inability to meet the demands of the agglomerations as they are settled, generating environments with low conditions of habitability. The supremacy of economic interests on natural ecosystems has established a complex network of impacts in raising resources to build the cities, from the extraction of material to the issuance of its final waste. In the last decades, several issues have been presented, many of them referring to urban systems, however, in spite of all the discussion related to preservation and restoration of ecosystems, there are still few transformations to be seen in the cities. This work aims to identify possible confrontations for this panorama, facing both the needs to meet demands for urban infrastructure and to preserve the environment by broadening the debate about implementation of solutions that comply characteristics and cycles of the territory, as well as increasing environmental quality to conviviality. Emphasis was given to the systems of rainwater management, since its inadequacies or shortcomings have been causing crescent collapses, with catastrophic consequences and severe damage to the affected populations. From reviewing some specific literature to this theme, such as Natural Engineering and Bioengineering of Soils, the concept of Urban Ecotechnique was defined, in which 8 variables have been outlined to analyze the application of 28 building techniques related to rainwater management systems, in order to evaluate the degree of service in qualitative sense. Finally, it has been done a discussion of the results from the interpolation of the information collected in an array, where the 28 techniques were crossed with the 8 variables, in an attempt to synthesize and better illustrate the result of the research process. It was noted that, in addition to the different degrees of service and readings generated, the association in chain of Ecotechniques and the cultural transformation of society can be guiding parameters of new attitudes to overcome the current situation. It was then concluded that the employment of Ecotechniques has been shown as a viable way of allying the resolution of urban environmental issues to the promotion of a cultural transformation that integrates people to the built environment, in a complete and natural way.