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Programa de Inclusão Digital (PID) no ensino fundamental em São Carlos (SP): mudanças e permanências com a chegada dos netbooks
(Universidade Federal de São Carlos, 2012-03-22)
Lemes, Fernanda Cristina Gaspar
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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/2437732024773137
Recuperação florestal através de semeadura direta: uso da superação de dormência e influência do tamanho de sementes e de gramíneas exóticas no estabelecimento de espécies de árvores
(Universidade Federal de São Carlos, 2012-03-22)
Pereira, Silvia Rahe
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Tanaka, Marcel Okamoto
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https://lattes.cnpq.br/2768658925977757
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https://lattes.cnpq.br/4490071418448583
Determinação sequencial rápida de As e Sb, Bi e Pb por espectrometria de absorção atômica com geração de hidretos
(Universidade Federal de São Carlos, 2012-03-22)
Batista, Érica Ferreira
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Pereira Filho, Edenir Rodrigues
;
;
https://lattes.cnpq.br/3830711529545975
In this study it was developed two systems, one for the fast sequencial determination of As and Sb and other for Bi and Pb using flame atomic absorption spectrometry with hydride generation. To optimize the system for the determination of As (193.7 nm) and Sb (217.6 nm) some variables were evaluated: concentration (in mol L-1) of HCl in the sample and carrier, concentrations (in % w v-1) of KI and NaBH4. For the system used in the determination of Bi (223.1 nm) and Pb (217.0 nm) the following variables were studied: concentration (in mol L-1) of HCl in the sample, concentrations (in % w v-1) of K3Fe(CN)6 and NaBH4. For these studies it was employed Doehlert design to select the best work conditions and obtain more information of the proposed methods. Some analytical parameters were obtained, respectively, for As, Sb, Bi and Pb: Limits of detection (LOD) (0.15; 0.16; 0.60 e 0.77 μg L-1), repeatability (RSD) (1.5; 2.0; 5.9; 6.0 %) and correlation coefficients (r) (0.999; 0.999; 0.998 e 0.997). In order to identify species that could interfere in the determination of As and Sb, Bi and Pb, a study was carried out considering the constituents commonly found in natural waters and chicken feed including Al(III), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II) and Zn(II). It was also carried out a study to investigate the influence of the concentration of HNO3 in the As and Sb, Bi and Pb determinations. Through studies with possible interferences, can be observed that there were no significant trend for As, Sb and Bi, the percentage of interference was lower than 21% (contrasts from -4 to 5% for both analytes). In the case of Pb it was noted a strong signal interference by Co (II), Cu (II), Fe (III) and Ni (II) with contrasts varying from -62 % to 29%. The effect of HNO3 concentration was not relevant if it is lower than 10 % v v-1 for As, Sb and 20 % v v-1 for Bi. However, it was noted a strong Pb signal suppression for HNO3 concentrations higher than 0.25 % v v-1. The systems developed were applied in the determination of As and Sb, Bi and Pd in Tietê river water, sea water of Praia Grande Ubatuba, chicken feed and to validate the methods were used two certificate reference materials: Nist 1643e (Trace elements in water) e TMDW-HPS (Trace metals in drinking water).
Degradação eletroquímica de compostos fenólicos usando eletrodo de diamante dopado com boro
(Universidade Federal de São Carlos, 2012-03-22)
Souza, Renata Beraldo Alencar de
;
Ruotolo, Luís Augusto Martins
;
https://lattes.cnpq.br/8409898535548523
The presence of organic compounds in industrial effluents is a serious environmental issue as well as for the human health, since most of those compounds are extremely toxic. The treatment of those effluents is done many times using biological processes; however some classes of compounds, among the phenolic ones, are resistant to this kind of treatment and require the use of technologies known as Advanced Oxidation Processes, that are based on the chemical or photochemical generation of oxidant radicals. The electrochemical technology emerged as an environmentally compatible alternative with advantages such as the elimination of transport and storage of dangerous chemical products, decrease of workforce and easiness to control the process. On this dissertation were systematically studied the variables of process and project of an electrochemical system using a boron-doped diamond anode for the oxidation of phenolic compounds aiming at current efficiency increase and, therefore, the decrease of energy consumption in the process. In a first phase it was studied the oxidation of the phenol using a reactor either with and without membrane, on the presence or absence of chloride. After that it was studied the influence of the kind of supporting electrolyte and its concentration on the process of oxidation of phenol, the interaction of the process and project variables analyzed, the effect of the flow rate, current density and concentration of chloride on the degradation of phenol and finally, the electrochemical degradation of a real effluent coming from a petroleum refinery. The results show that the use of a membrane had no significant influence on the kinetics of oxidation when compared with the reactor without membrane, mainly when the chloride ions were present on the solution, and that with the use of the membrane the highest cell potentials were achieved. In face of this, it was opted by the utilization of a reactor with one compartment. Overall, it was observed that the utilization of different supporting electrolytes did not interfere on a significant way on the process; however when supporting electrolytes of sulfuric acid, sodium sulfate or calcium carbonate were used there was an improvement of the process in terms of current efficiency and energy consumption. Still, generally, the presence of chloride ions leads to an increase on the kinetics of removal of chemical oxygen demand (COD) e total phenolic compounds (TPC). With respect to the interaction of process and project variables, it was verified that for both currents used, in most cases, the kinetics of degradation is weakly influenced by the distance between the electrodes. The increase on the current density leads to a faster speed on the degradation process, however there is a potential cell increase. The increase on flow rate provides, besides a faster kinetics, an improvement on current efficiency, due to enhancement of mass transport. As for the degradation of the real effluent, it was found that the use of lower current densities is essential to accomplish lower cell potentials to enable the utilization of the electrooxidation process in terms of global energetic consumption.
Falas Waikhana: conhecimento e transformações no alto rio Negro (rio Papuri)
(Universidade Federal de São Carlos, 2012-03-23)
Silva, Aline Scolfaro Caetano da
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Andrello, Geraldo Luciano
;
https://lattes.cnpq.br/5447074379881029
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https://lattes.cnpq.br/9307937859005364
Result of an ethnographic research among the Waikhana (Pira-Tapuia), a Tukanoan group that lives around the Uaupes basin, Amazonian Northwest, this dissertation focuses on hierarchy and circulation of knowledge in Uaupes contemporary context. This context is characterized by what has been called by the indigenous groups as culture recovery and revitalization movement . Involved in this local dynamics, the Waikhana attempt to recover by one side some ritual practices and traditional techniques of environment handling and by the other side the written record of certain oral knowledge in former times updated and transacted in ritual occasions. Trying to understand the way the indigenous are experiencing those processes and emphasizing their developments in the sphere of their own sociopolitical relations, this text approaches some classical themes on regional literature concerning social organization and cosmology. Some interpretations and redirections made by the indigenous themselves, concerning the problematic of hierarchy and circulation of knowledge will be presented. And will show that these interpretations and redirections bring some relations and positions of a Waikhana (cosmos) politics up to date.
Zoneamento geoambiental da bacia do rio Fartura: abrangendo os municípios de São José do Rio Pardo-SP, São Sebastião da Grama-SP, Vargem Grande do Sul-SP e Águas da Prata-SP, na escala 1:50.000
(Universidade Federal de São Carlos, 2012-03-23)
Faleiros, Cássia de ávila Ribeiro Junqueira
;
Lorandi, Reinaldo
;
https://lattes.cnpq.br/7794241793056671
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https://lattes.cnpq.br/2509932249426122
Grounded on geo-environmental zoning, this study seeks to contribute to the discussion about environmental management in light of sustainable development, thus bringing together economic development and environmental constraints. The 227km2 study area the Fartura river basin comprises the municipalities of Sao Jose Do Rio Pardo, Sebastiao da Grama, Vargem Grande do Sul, and Aguas da Prata, in the State of Sao Paulo, Brazil. The purpose of this study is to propose ways to organize activities as the populations of these municipalities increase, thereby promoting sustainable occupation of the physical environment in accordance with existing urban planning guidelines and legislation. To this end, geo-environmental zoning of this river basin was conducted by means of remote sensing and geo-processing (GIS) technologies. From cartographic documentation and field/lab work results, an environmental diagnosis was produced, including information relevant to environmental planning of the watershed in question. During prognosis, several occupation scenarios for the Fartura river basin were worked out for the 1987, 2000, and 2010 periods. They shed light on the urban expansion dynamics, land use/economic activities, and native vegetation conservation patterns of these municipalities. This prognosis ultimately indicated emerging occupation trends for this river basin and brought about guidelines for land-use planning. Moreover, it was possible to verify that its bedrock is quite homogeneous, 70% of which pertaining to the Varginha Complex. With regard to its soil texture, it was found that 47% of the Fartura river basin soil is sandy and that 86% of the soil composition of the total watershed area is over 50% sand. As to its declivity, it was shown that although 14% of the water basin area displays declivities higher than 30%, most of which falls within the 5%-20% declivity range. This factor, along with its soil texture, suggests a high likelihood of erosion processes happening in this water basin. In addition, inappropriate land use in APPs (Permanent Conservation Areas) can lead to erosion and silting in sections of the watershed area where sandy soil prevails and to flooding where more clayey soils occur. It was also attested that 35% of the area has induced occupation and 24% restricted occupation. The remaining sections should be occupied in a controlled manner under specific conditions and their use should combine farming with cattle-raising, with a view to both land rotation and soil fertility. Level sections of the Fartura river basin area may profit from mechanized farming, to which soil management/conservation techniques must be applied. As to urban occupation, the area under study showed a gradual increase (1.19%).
O mapeamento dos conflitos socioambientais de Mato Grosso: denunciando injustiças ambientais e anunciando táticas de resistência
(Universidade Federal de São Carlos, 2012-03-23)
Silva, Michelle Tatiane Jaber da
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Sato, Michele
;
https://lattes.cnpq.br/9264997837722900
;
https://lattes.cnpq.br/8921793262672558
The State of Mato Grosso-Brazil, locus of this research, is singular from the ecological point of view, encompassing three important biomes: Amazon, Cerrado (Savannah) and Pantanal, and also a peculiar ecosystem called Araguaia. However, in this landscape there is a contrast between the results of the search for economic growth strongly centred on the activities of the agribusiness, of the power plants and other activities that are the driving force of significant socio-environmental conflicts. These conflicts that emerge when at least one of the groups has the continuity of their ways of life threatened by undesirable environmental impacts, due to the action of other groups. The understanding of such a diverse dynamic that is present in this territory is emphasized in this research, since the main aim of this thesis is to map the main social environmental conflicts that are in the 12 planning regions of Mato Grosso, from the narratives of the vulnerable social groups. In this context, we consider that the vulnerable social groups are the most affected by this model and we presuppose that in places where the conflicts are more intense, the tactics of resistance and organized forms are also more expressive. So, in order to investigate such issues, we started in 2008 a research Project Mapping of identities and territories of the State of Mato Grosso , developed by the Environmental Education, Communication and Arts Research Group of the Federal University of Mato Grosso, sponsored by the Mato Grosso State Research Support Foundation. In this project we have promoted two Seminars on Social Mapping, which occurred in the city of Cuiabá-MT, in 2008 and 2010. In each one about 250 people took part in the seminar, representatives of several social groups of the State. To understand this vigorous broth we used a methodological complexity which composes the epistemological contribution provided by the phenomenology, linked to the praxis of the social map and by the axiological values inspired in the cartography of the imaginary. In this way, we presented in this thesis a general view of the socio-environmental conflicts that were mapped, allowing for a picture of the global landscape of MT. Besides, we offered some settings of the local landscape, showing the struggles of some specific social groups, which are: Mata Cavalo Slave`s Descendant Black Community (Quilombo), Pantanal`s Community of São Pedro de Joselândia Community, Xavante People of the Indigenous Land of Marãwaitsédé and Rubbertappers of Guariba & Roosevelt Extractivist Reserve. Subsidized by the use of technologies of the geo-referenced database processing, we presented a spatialization of the Map on the socioenvironmental conflicts of the State of Mato Grosso with 194 points of conflicts identified, places where death threatens and slave work exists. The participant`s narratives point to the understanding that the mapped conflicts are expressions of the development model that leads to the destructions of the ecosystems and the annihilation of singular forms of life. The mapping reveals that the main direct driving forces of the conflicts are: dispute for the land, dispute for water, deforestation, burning and abusive use of agricultural pesticides. Opposite to the striking practices, several tactics of resistance appear, that go from the legal procedures to the most subversive ones. Thus, from an environmental education point of viewthat aims for the social changes with ecological responsibility, we consider that the results shown in this study may become a referential to the researchers, governments and civil society; that when elaborating public policies, they can take into account the socio-environmental conflicts in their decisionmakings, seeking for the participation as one of the driving forces of the conceptual, political and scientific for the world transformation.
Propriedades mecânicas das ligas Ti34Cu36Ni8Zr22 e (TiZr)80Co12Fe8
(Universidade Federal de São Carlos, 2012-03-23)
Medeiros, Marcia Moreira
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Bolfarini, Claudemiro
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https://lattes.cnpq.br/9231627080617037
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https://lattes.cnpq.br/8260391121543962
Bulk amorphous and nanocrystalline alloys have attracted great interest from the scientific community. Titanium based alloys have demonstrated potential for formation of amorphous. This study aimed at to evaluate the mechanical properties of the Ti34Cu36Ni8Zr22 and (TiZr)80Co12Fe8 alloys, at room temperature. Thereby, nanoindentation, compression and three points bending tests were performed. The methodology involved the following steps: (i) production of alloys by arc melting under argon atmosphere, (ii) production of amorphous ribbon by melt-spinning, (iii) heat treatment of the ribbons at different temperatures, (iv) production of test specimens through casting in copper chill followed by quenching (v) microstructural characterization via scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD), (vi) mechanical characterization based on nanoindentation, compression and torsion tests. The results of nanoindentation showed an increase in hardness and reduced Young's modulus as the temperature of the heat treatment approachs the crystallization temperature. Results of compression and bending showed strong dependence on the preparation surface and internal defects of the specimens. The Young's modules and tensile strengths are below those reported in the literature, probably due to internal defects present in the samples such as pores.
Estudos das relações estrutura-toxicidade de agrotóxicos
(Universidade Federal de São Carlos, 2012-03-23)
Kurohane, Cesar Augusto
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Montanari, Carlos Alberto
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https://lattes.cnpq.br/9200533791228786
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https://lattes.cnpq.br/8340874473138451
Computational methods such as electrostatic and structural similarity of compounds were used to determine a similarity pattern for pesticides present in the database of the Medicinal Chemistry Group IQSC/USP. A collection consisting of herbicides and insecticides allowed and banned, according to the World Health Organization was used in this study. Several chemometric analyzes were performed to determine the recognition pattern processes in the classification of substances into their chemical classes that were associated with levels of 61-86% of correct prediction. Three case studies were carried out to validate the established hypotheses which showed good results in all cases. The disclosure of chemical space associated with the biological space using robust methods of analysis led to the establishment of rules for the selection and identification of patterns that can now be used as the foundation for the design of new herbicides and insecticides.
Modificação das propriedades dos polímeros comerciais de SBR e NBR a partir da incorporação de nanopartículas sintéticas
(Universidade Federal de São Carlos, 2012-03-23)
Arantes, Tatiane Moraes
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Camargo, Emerson Rodrigues de
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https://lattes.cnpq.br/7720754304065239
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https://lattes.cnpq.br/9039822138866007
Numerous efforts have focused on the search for new materials involving lower cost, greater durability and, especially, lower environmental impact. In this sense, polymer nanocomposites have become the focus of many research groups because of their superior mechanical and thermal properties. In this work, nanocomposites of SBR and NBR with silica nanoparticles and synthetic clay Laponite, without and with the surface modification with silane 3-(trimethoxysilyl) propyl methacrylate (TMSPM), were prepared by means of simple mix of components using the colloidal route. The nanocomposites of SBR and NBR with Laponita showed exfoliated structure, with the presence of clay tactoids intercalated by the polymeric matrix, with homogeneity at the nanometric level and lower molecular mobility. The nanacomposites had increase in the thermal stability than the pure polymer and the mechanical properties showed a increase in storage modulus, loss modulus and damping properties (noise, vibration). Nanocomposites of SBR and NBR with Laponite functionalized with TMSPM also been prepared and presented structure intercaled with the presence of clays tactoids. There was a reduction in molecular mobility and increased in the glass transition temperature (Tg) with increase of the Laponite content. The silica nanoparticles were synthesized by controlled hydrolysis and condensation of tetraethyl orthosilicate (TEOS) in an alcoholic medium. In addition, silica nanoparticles are functionalized with TMSPM. The nanocomposites of SBR and NBR with silica nanoparticles with and without the surface functionalization were prepared by the colloidal route. Nanocomposites showed silica agglomerates in the form three-dimensional structure nanoparticles with and without modification in the SBR and NBR. The nanocomposites of SBR and NBR with silica showed a decrease in Tg, around 10 °C, increase in storage and loss modulus and damping properties with the increased amount of silica.
Características antropométricas e posturais de pés de idosos diabéticos e não diabéticos: evolução no período de quatro anos
(Universidade Federal de São Carlos, 2012-03-23)
Aquino, Victor da Silva
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Rebelatto, José Rubens
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https://lattes.cnpq.br/1684247449456330
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https://lattes.cnpq.br/0894735020809128
The aging of the population is a phenomena observed in the whole planet. Brazil follows this tendency with 21 million elderly, who correspond to 11,3% of the population. The projection is that in the year 2025 the population of elderly in Brazil will increase 16 times against five times the total population reaching, in absolute values, the sixth position in elderly population in the world. Close to 10 to 15% of the Brazilian population with age superior to 50 years has Diabetes Mellitus12. Due to the lack of studies which observed the behavior of anthropometric and postural measures in elderly diabetic in the long term, the objective of this paper was to investigate, in the period of 4 years, which anthropometric and postural alterations occur in the feet of elderly diabetic and, compare them with non-diabetic elderly. Four hundred and three individuals with 60 years of age or more were contacted, who participated of the study previous to 2006, of which 165 accepted to participate again. In this way, the current paper had four groups of participants, Diabetics 2006 (72), Diabetics 2010 (26), Non-Diabetics 2006 (331) and Non-Diabetics 2010 (139). All the participants answered an interview-questionnaire that contemplated social aspects, orthopedic investigation and the presence of pain. At the end of each evaluation the individual was invited to a re-evaluation after one week, with the purpose of verifying the trustworthiness of the measurements carried out by the same examiner at different moments. For the analysis of the anthropometric variables and of Arch Index, between the years 2006 and 2010, the groups were composed of 165 individuals, of which 26 were diabetic and 139 non-diabetic. On the other hand, for the Foot Posture Index IPP and its six criteria, groups of Diabetics were composed of 72 individuals in 2006 and 26 in 2010; and for comparison in the Non-diabetics, the 2006 group was composed of 331 individuals and the 2010 group of 139. The characterization of the sample was made by means of descriptive analysis, with central tendency and dispersion measures. Throughout 4 years, a reduction of the Length of the feet, reduction in the Height of the 1st Finger, of the Angle of the 1st Metatarsofalangeana Articulation was found between the Diabetics and Nondiabetics. There was also an increase in the Arch Index in the same period in both groups. In the comparison of the postural variables, the group of Non-diabetics changed more than the Diabetics group. The changes that occurred were, an increase of the percentage of neutral feet and a reduction in the alterations.
Uso de imagens digitais e ferramentas quimiométricas para identificação e determinação de Cr (VI) em solos contaminados
(Universidade Federal de São Carlos, 2012-03-23)
Oliveira, Luciana Fontes de
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Pereira Filho, Edenir Rodrigues
;
https://lattes.cnpq.br/3394181280355442
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https://lattes.cnpq.br/1848439223921790
The determination of toxic metals in soils is an important factor to access their quality or identify possible contamination. The element Cr has double feature: Cr (III) is essential for human beings and Cr (VI) is toxic. In this context, the aim of this work is to propose a simple test for the determination of Cr (VI) in soil samples using digital images and chemometric tools. The samples used in this project were collected at Maritime Antarctica, around the Comandante Ferraz Antarctic Station (a Brazilian scientific station). Alkaline medium was used to extract Cr (VI) of the samples and the chromogenic reagent was added to color development. To obtain the digital images, the extracts were placed in Petri dishes and a multifunction printer was employed. The results were compared with those calculated by molecular absorption spectrometry. For the images, the MatLab program version R2009a was used to obtain the mean values of colors R, G, B, H, S, V, r, g, b and L, and the Pirouette 4.0 program to the chemometric tools application. The digital images were evaluated in order to be applied for the proposition of models of classification and supervised calibration method PLS (Partial Least Squares). Two types of preprocessing were used to calculate PLS models: autoscaled and mean centered. For the calibration set was used the blanks and standards in a total of 52 solutions and as validation set was used 44 solutions (samples replicas). The model using the mean centered preprocessing was better. Furthermore, when the real values were compared with the predicted the coefficient of correlation was 0,991. It is evident that the proposed method is a simple strategy with low cost for the detection of Cr (VI) in soil samples. Furthermore, the images have great potential to be applied for classification models. The Pb determination using digital images was also tested, but problems with the solutions pH did not permit the application of the methodology for real samples.
Estimação clássica e bayesiana para relação espécieárea com distribuições truncadas no zero
(Universidade Federal de São Carlos, 2012-03-23)
Arrabal, Claude Thiago
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Andrade Filho, Marinho Gomes de
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https://lattes.cnpq.br/4126245980112687
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https://lattes.cnpq.br/0235029522811813
In ecology, understanding the species-area relationship (SARs) are extremely important to determine species diversity. SARs are fundamental to assess the impact due to the destruction of natural habitats, creation of biodiversity maps, to determine the minimum area to preserve. In this study, the number of species is observed in different area sizes. These studies are referred in the literature through nonlinear models without assuming any distribution for the data. In this situation, it only makes sense to consider areas in which the counts of species are greater than zero. As the dependent variable is a count data, we assume that this variable comes from a known distribution for discrete data positive. In this paper, we used the zero truncated Poisson distribution (ZTP) and zero truncated Negative Binomial (ZTNB) to represent the probability distribution of the random variable species diversity number. To describe the relationship between species diversity and habitat, we consider nonlinear models with asymptotic behavior: Exponencial Negativo, Weibull, Logístico, Chapman-Richards, Gompertz e Beta. In this paper, we take a Bayesian approach to fit models. With the purpose of obtain the conditional distributions, we propose the use of latent variables to implement the Gibbs sampler. Introducing a comparative study through simulated data and will consider an application to a real data set.
O diálogo entre aspectos da cultura científica com as culturas infantis na educação infantil
(Universidade Federal de São Carlos, 2012-03-25)
Fagionato-Ruffino, Sandra
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Pierson, Alice Helena Campos
This research is the result of concerns about different ways of thinking and approaching the natural sciences in early childhood education. Assumes that before children go to school already have contact with the scientific aspects of the mass media, by the contact with parents and other adults or bigger children, or even by the direct contact with elements and phenomena related to natural sciences. Likewise, these aspects are present in early childhood education institution, in some cases lending the discipline form and how it is used to educate in elementary school. In this sense, this study aims to identify children in interaction with pairs, with adults and everything that surrounds them, their actions, perceptions and ways of meaning from the natural world and technological pondering how to insert elements of scientific culture in the space of childhood , without stacking it to children. We sought to identify the elements or natural phenomena and technological perceived or handled by children, to know the social and cultural experiences for the scientific culture that children share with other children and adults and to analyze the characteristics of the experiences triggered by the merger of practices related to scientific culture within early childhood education. Childhood is understood as a social category and children as social actors, members of this category and producing crops. The qualitative research was based on studies of childhood and the ideas of Humberto Maturana on autopoiesis, cognition, language and emotion. The interest was mainly focused on the experiences of children in free play and activities directed by the teacher who was also the researcher. Analysis of data obtained by means of video recording, photo, logbook of the researcher and children s drawings, led to the conclusion that the experience of children with aspects of scientific culture, they give different names to the same thing, create forms of expressions to explain what they think, think with different logics, between reality and fantasy; have different ideas on the same element or phenomenon arising from their previous experiences with influences like family, religion, television and the observation of nature. The commitment to their ideas seems to be less important than the affective interests and their pair s comments trigger argument, reformulation of the previous explanation or the incorporation of new elements. In the act of children's investigating the most important is the interaction itself, not an explanation of what is observed. Their actions do not go towards the assimilation of procedures and explanations, but of creation. In this sense, it is important to consider the scientific knowledge as one more among many others that comes from other areas of experience, without characterizing it as absolute truths.
O ensino de funções em escola técnica de nível médio por meio da modelagem matemática e uso da calculadora gráfica
(Universidade Federal de São Carlos, 2012-03-26)
Bilhéo, Luiz Alfredo Dealis
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Baldin, Yuriko Yamamoto
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https://lattes.cnpq.br/8785562528979416
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https://lattes.cnpq.br/7263619227486687
The difficulty of students in learning concepts of mathematics especially at high schools is current problem in Brazilian schools. This difficulty is a challenge even bigger as the different high school systems are considered, for example, the technical professional high schools. Such challenge for two classrooms of first grade (10th grade in K-12) of a technical course in environmental studies motivated the proposal of this dissertation. The research work explored a teaching methodology of the concept of function that would show to the student the importance of this concept in a technical course, while offering an opportunity to know about the mathematics modeling that uses functions, especially those from school curriculum. The final results of this dissertation consisted of working sheets that were planned, executed and evaluated in two classrooms. The worksheets are formatted so that they can be used by teachers who share the same challenge and interest in developing research to improve the teaching/learning mathematics at high - school level. The proposed activities are based on mathematics modeling of problems in the context of the students course, and on the educational use of a graphic calculator to construct tables, graphs and regression curves. The official documents from Ministry of Education (MEC) about curriculum standards and some theoretical references have been used for our reflections about the differences between traditional teaching style and new educational trends, and about the potential of technology to improve the learning. The work presents also a study of the concept of function that supported the planning of the proposed classroom activities.
Transmissão intergeracional de práticas relativas a estudo em famílias com estudantes no ensino básico
(Universidade Federal de São Carlos, 2012-03-26)
Cunha, Renan Soares Mendes Teixeira da
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Cortegoso, Ana Lúcia
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https://lattes.cnpq.br/3853989531345390
Children socialization development is influenced by their parents through parental style and practices. Parents can assume the function of promoting agents of study behavior of their children through parental practices. Results of training programs directed to parents as study supervisors show that they have difficulties to behave more accordingly to supervision practices which the literature accepts as more adequate. An explicative hypothesis for that is that parents learned to supervise their children according to the conditions and models their parents used with them. This possibility can be illustrative of a situation of intergenerational transmission of parental practices relating to studying situation. Articulating with concepts of the Behavior Analysis, this research objective was to investigate which are the possible relations between the conditions created for the development of parents´ study repertory and the conditions created by parents to the development of their children study repertory. Participants of this research where representatives of three generations maternal grandmother, mother and child studying at the fundamental grades of public schools, of five families. Grandmothers were aged between 53 and 69 and had scholar degree between none and third grade of supplementary high school; mothers were aged between 33 and 41 and had scholar degree between second grade of fundamental school and post-graduation at a specialization level; children were aged between 9 and 13 and had scholar degree between third grade/fourth year and sixth grade/seventh year of fundamental school. Data were accessed through semi-structured interviews, taken individually and separately with each participant, at their residences or workplaces. The interviews were recorded, when agreed, or written down, when not agreed. All of the participants signed TCLEs. The research was approved by the Ethic Committee of UFSCar. The method of data analysis consisted in categorizing the collected information, grouping them into variables which influence studying (local of study, time of study, supervisor´s responses to mistakes and hits, etc.). Using the synthesis of the reports of the dyad mother-child related to the conditions focusing the child and of the reports of the dyad grandmother-mother related to past study conditions focusing the mother when she was a student, comparative frameworks were built, indicating which variables or variable values were similar or different between the three generations and, when it was possible, which kind of similarity. Finally, frameworks were built with synthesis of identifyed aspects, indicating intergenerational continuities and discontinuities to each family. Results showed that for Family 1, about the dyad grandmother-mother there was continuity for six variable values and discontinuity for four, about the dyad motherchild there was continuity for thirteen values and discontinuity for two; for Family 2, about the dyad grandmother-mother there was continuity for one variable value and no discontinuity, about the dyad mother-child there was continuity for six values and discontinuity for two; for Family 3, about the dyad grandmother-mother there was no continuity for one value and no discontinuity, about the dyad motherchild there was continuity for eleven values and discontinuity for eight; for Family 4, about the dyad grandmother-mother there was continuity for four variable values and discontinuity for one, about the dyad mother-child there was continuity for eight values and discontinuity for three. ; for Family 5, about the dyad grandmother mother there was continuity for five values and discontinuity for another five, about the dyad mother child there was continuity for eight values and discontinuity for seven. It was vereified a strong tendency of intergenerational continuity of responses, behaviors and conditions related to the study, accordingly to the initial hypothesis. Through the data it was possible to discuss which aspects of children study parents observe, value and consequence. Results can subside future training programs directed to parents as favoring of their children study behaviors.
Problemas de autovalores de Steklov-Neumann e aplicações
(Universidade Federal de São Carlos, 2012-03-26)
Godoi, Juliano Damião Bittencourt de
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Tomazella, João Nivaldo
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https://lattes.cnpq.br/0051564735964760
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https://lattes.cnpq.br/7641553268884764
In this work we will obtain four main results of existence of weak solution, three of them to elliptic partial di_erential systems with nonlinear boundary conditions and the other to elliptic partial di_erential equations with nonlinear boundary conditions associated with operator p-laplacian. These results will be obtained when there is a kind of interaction among the reaction nonlinearities and the Neumann spectra and an interaction among the boundary nonlinearities and the Steklov spectra, associated with the systems or equations. The tool that we will use is fundamentally based on minimax methods in critical point theory.
Aplicação da fluidodinâmica computacional na avaliação da hidrodinâmica de estágio em colunas de destilação
(Universidade Federal de São Carlos, 2012-03-26)
Justi, Gabriel Henrique
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Gonçalves, José Antônio Silveira
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https://lattes.cnpq.br/0337997526924402
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https://lattes.cnpq.br/0170230384799537
The development of the design of chemical processes has received increasing improvement, incorporating sophisticated mathematical models, which allowed better simulation of its real behavior. The distillation column is one of the most widely used separation equipment in the industry and therefore, its perfect working and optimization are economically crucial factors. Thus, the study of the hydrodynamic in distillation column sieve trays has increased over the years with the purpose to optimize the flow patterns, which is of great importance on the mass and energy transfer efficient. Due to the development of powerful computers, advances in numerical methods and improvement in models of multiphase flows, the investigation of complex flow problems is possible. One way to investigate these problems is to use Computational Fluid Dynamics. Thus, in this work we used commercial package CFD software to predict the hydrodynamics in a sieve tray, with the main objective to evaluate the velocity fields and compare them with the experimental work of Solari and Bell (1986). We proposed a two-fluid model with Eulerian-Eulerian framework, three-dimensional (3D), steady-state and the standard k-ε turbulence model for air/water system at 1 atm. The continuity and momentum conservation equations were used to describe the gas and liquid phases. The simulated sieve tray geometry was based on experimental work of Solari e Bell (1986). The simulation domain included the downcomer region. New sieve tray geometry design was proposed to evaluate the hydrodynamics. The results show the velocity profiles, volume fractions and liquid recirculation zones on the sieve tray for several combination of liquid and gas flow rates. The simulation indicated the presence of recirculation and stagnation zones, and it reproduced satisfactorily the results of Solari e Bell (1986) and the new geometry design reduced the liquid recirculation zones on tray. The proposed methodology in this work proved to be appropriate and the Computational Fluid Dynamics (CFD) techniques presented to be an important tool in the design and optimization of sieve trays.
Efeitos de spin em diodos de tunelamento ressonante tipo-p
(Universidade Federal de São Carlos, 2012-03-27)
Galeti, Helder Vinicius Avanço
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Gobato, Yara Galvão
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https://lattes.cnpq.br/7558531056409406
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https://lattes.cnpq.br/3876752605313288
In this work, we have investigated the spin effects in p-i-p GaAs/AlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. The spin-dependent tunneling of carriers was studied by analyzing the current-voltage characteristics (I(V)) and the right (+) and left (-) circular polarized PL from the contact layers and the QW as a function of the applied bias. We have observed that the polarization degree from QW and contact emission is highly bias voltage sensitive. For low voltages the QW polarization exhibits strong oscillations with values up to 50% at 15 T and sign inversions for the voltages corresponding to the resonant tunneling of carriers into the well. The GaAs contact emission shows several bands including the indirect recombination between free electrons and holes localized at the 2DHG formed at the accumulation layer (2DHG-e). We have evidence that the spin polarized hole gas can contribute to the circular polarization degree of carriers in the QW. However, our results show that the circular polarization of the carriers in the QW is a complex issue which depends on various points, including the g-factors of the different layers, the spin-polarization of carriers in the contact layers, the density of carriers along the structure and the Rashba effect. The temporal evolution of the spin-polarization carriers was also investigated. We have measured the time-resolved polarized PL emission from the GaAs quantum well (QW) of a p-i-p GaAs/AlAs Resonant Tunneling Device (RTD). We have used a linearly-polarized Ti:Saphire laser and tuned below the QW absorption edge. Therefore, the electrons are created solely at the top GaAs layer and with no defined spin polarization. Under applied bias, the tunneling holes from the p-doping contact attain a quasi-stationary distribution along the RTD structure, while electrons are only photocreated during the pulse excitation with a ps Ti:Sa laser. These photogenerated electrons are driven by the applied bias and tunnel into the QW, where they might recombine with holes or tunnel out of the well. Under illumination, the current-voltage characteristics of the device present two additional features attributed, respectively, to resonant and -X electron tunneling. Optical measurements for biases where these two alternative transport mechanisms have competitive probabilities revealed an unusual carrier dynamics. The quantum well emission is strongly delayed and we observe a remarkable nonlinear effect where the emission intensity decreases at the arrival of a laser pulse. We propose a simple model that adequately describes our results where we assume that the indirect transition rate depends on the density of electrons accumulated along the structure. Under magnetic field, the PL transients reveal two rather distinct time constants, a short time ( ~ 1 ns) and a long one, which is longer than the laser repetition time (> 12 ns). The bi-exponential behavior indicates additional electron-tunneling processes, which may be associated to indirect tunneling through X-AlAs levels and tunneling of hot vs quasiequilibrium carriers at the accumulation layer. Immediately after the laser pulse, while the faster tunneling process dominates, the QW emission shows a rather small polarization. As the faster tunneling process dies out, the polarization increases to a value that remains approximately constant along the whole transient. This result demonstrates that electrons tunneling through these two distinct processes should present different spin-polarization values. We have also observed that at low biases, around to the expected -X resonance , the QW polarization is very sensitive to the excitation intensity, showing a signal inversion as a function the laser intensity. We attribute this effect to a critical dependence of the electron polarization on the occupation of the various levels involved on the process. Furthermore, at large biases, the long decay component almost disappears for low-excitation conditions and show an unusual time-dependent polarization behavior under high-excitation regime. For the analysis of this complex dynamics, we have also considered the process of tunneling out of the QW, which should become more effective, competing with the radiactive recombination process under high bias voltages. Finally, our results reveal new insights on the mechanisms that determine the spin-polarization of carriers tunneling through a doublebarrier structure and can be explored to develop spin-filter devices based on a RTD structure.
Responder por exclusão em treinos de discriminação condicional com estímulos temporais por universitários
(Universidade Federal de São Carlos, 2012-03-27)
Cippola, Nathália Sabaine
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Domeniconi, Camila
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https://lattes.cnpq.br/9684535663947328
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https://lattes.cnpq.br/1911605025436199
Choose by exclusion has been extensively investigated and documented in different human populations. The pattern of conditional discrimination of an undefined stimulus obtained for an undefined model when possible experimentally defined choices exist has attracted the attention of researchers interested in symbolic processes such as vocabulary acquisition. Studies employing concrete stimuli have generated compelling data at the same time that they have also highlighted the need for refining knowledge about the properties of the stimuli controlling the response. The utilization of a onedimensional stimulus, like time, could add empirical data about the exact moment when the participant starts to see the undefined stimulus as being different from those used during training. Temporal stimuli have been applied in many investigations of temporal perception. In this context, this work aims to verify how university students respond to exclusion tasks and generalization tests using temporal stimuli as the stimulus mode,on the basis of double temporal bisection trainings. Forty-four university students aged between 18 and 26 years participated in this study, conducted under four different experimental conditions. For the first condition, training consisted in the formation of two conditionals between stimuli lasting 0.5 and 2 seconds for the colors red and green (first bisection), and the relation between stimuli lasting 2 and 8 seconds for the colors blue and yellow (second bisection).For the second condition, the model stimuli lasted 0.3 and 1.2 seconds for red and green, and 1.2 and 4.8for blue and yellow. Models with even shorter duration were utilized for the third and fourth conditions, 0.2 and 0.6,and 0.6 and 1.8 seconds for red and green, and blue and yellow, respectively. The other difference between the conditions lay on the stimulus mode; i.e., visual (time during which a black square remained on the screen) for the first three conditions, and auditory (time during which a beep could be heard) for the last condition. Once the baseline was established, we conducted five blocks of generalization tests with attempts consisting in the presentation of model stimuli lasting for a time period different from the trained periods and undefined and defined comparison stimuli (colors). The generalization test results revealed that the preference for red diminished with longer stimuli, and that the preference for yellow followed an inverse trend. Compared with blue, the choice of green was more frequent during shorter time intervals. As for the Exclusion Test, there was preference for defined stimuli compared with stimuli closer to the trained ones and for undefined stimuli compared with periods less close to the trained ones. These findings contribute to the investigation of responding by exclusion, since there is preference for the undefined stimulus compared with models never seen previously, especially if the models are distant from the trained ones. The generalization data differed from those achieved for non-humans, which opens a discussion about temporal discrimination learning and the role of verbalization and counting.