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Mapeamento de QTLs para características de crescimento e de resistência no cromossomo 14 de bovinos F2 provenientes de um cruzamento Gir x Holandês
(Universidade Federal de São Carlos, 2006-06-30)
Miyata, Marcelo
;
Regitano, Luciana Correia de Almeida
Brazil possesses the largest commercial bovine herd in the world and cattle represents about 43% of agricultural PIB of Brazil. Crossing Bos taurus and Bos indicus species allows the combination of traits of production from the first specie and of rusticity from the second specie for the genetic improvement of the bovines. Due to the economical relevance of livestock in Brazil, the search for regions in the genome that contribute to prodution traits is object of many studies including traits such as meat yield, precocity of growth and many weight measures (eg. birth weight, yearling weight). The endoparasites and ectoparasites have great economical relevance, once the growth losses and production (meat and milk) affect the bovine herd and consequently, the producer and consumer. The objective of this work was to map QTL (Quantitative Trait Loci) for growth traits and for resistance to ectoparasite and endoparasites through the BTA14 scan, using microssatellite markers in a F2 population Holstein x Gyr. The QTL mapping for the trait birth weight (BW) suggested a QTL (P <0.05) at 1 cM from centromere and for the weight at 60 days (P60), a suggestive QTL (P <0.05) was found at 0 cM from centromere. The mapping for resistance to the ectoparasite Boophilus microplus revealed a significant QTL (P<0.01) at 22 cM from centromere but no association was observed for endoparasites. Together, the results found in this work suggest the possibility to map regions of the bovine genome that affect quantitative traits, like growth and resistance, by means of microssatellite markers.
Avaliação do comportamento das elementos Ni, Rb e Se por espectrometria de absorção atômica com forno tubular na chama de aeressol térmico.
(Universidade Federal de São Carlos, 2006-06-30)
Rosini, Fabiana
;
Nóbrega, Joaquim de Araújo
;
https://lattes.cnpq.br/8833989058164529
;
https://lattes.cnpq.br/5754458321462608
In the present work the behavior of the elements Ni, Rb, and Se was evaluated by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS). The arrangement of the TS-FF-AAS system consisted of a Ni tube located on the burner head of an air / acetylene flame with a ceramic capillary tube connected to it and heated by the flame. The sample was transported towards the capillary heated tube by action of a peristaltic pump, and then transformed in a thermospray that was introduced into the Ni tube. The sensitivity was increased by the complete introduction of the sample in the absorption volume. For all tested elements, the effect of the main parameters on atomization, such as flame composition, observation height, type of carrier stream, flow rate, and sample volume, was investigated. For selenium, the detection limit obtained was 95-fold better than that obtained by FAAS. Notwithstanding, selenium determination was difficult due to the absorption region of this element (λ = 196 nm), that implied in molecular absorption by flame gases and scattering of radiation. Based on prescribed conditions established by a factorial experiment, selenium was determined with accuracy in samples of animal tissues and in two standard reference materials after microwave-assisted digestion using a diluted solution of acid nitric. For Rb, the sensitivity increased 37-fold compared to FAAS, leading to a detection limit of 2.65 µg/L by TS-FF-AAS. On the other hand, Ni is a refractory element and needed special conditions to facilitate the volatilization and atomization processes. Thus, a cloud point extraction procedure was developed. The combination of both TS-FF-AAS and cloud point extraction led to an improvement of 18-fold in detection limit, however Ni determination in biological samples was limited owing to interferences caused by Al(III), Co(II), and Fe(III). These interferences could be solved by adding fluoride to the digests.
Resolubilidade global para operadores diferenciais parciais reais de ordem um
(Universidade Federal de São Carlos, 2006-06-30)
Silva, Maurício Fronza da
;
Santos Filho, José Ruidival Soares dos
;
https://lattes.cnpq.br/6112529384454347
The present work study the global solvability of first order real linear partial diferential operators when the principal part has precisely one equilibrium point. Moreover, examples and counterexamples are presented.
O texto na apropriação da escrita
(Universidade Federal de São Carlos, 2006-07-03)
Giovani, Fabiana
;
Reyes, Cláudia Raimundo
The main objective of this work is to understand the process of acquiring the writing system which children from the outskirts underwent during the literacy period. It was a peculiar situation in which the teacher, by using the enunciation theory as the foundation for her practice, became a researcher and constructed a corpus of analysis from the texts written by the children a material developed without aiming to be transformed into an academic research. The theoreticalmethodological presupposition of this qualitative investigation refers to a tracing paradigm of analysis which was established within the ambit of Human Sciences and enabled an analysis based on the traces present in the children s texts. The search for traces was related to the conditions or context in which the texts were produced, as well as to the set of stable characteristics of the discursive genre and the writing of the words. Consonant with these pillars which guided the sight to the texts is the choice for the theoretical referential mainly represented by Mikhail Bakhtin. From the traces in the texts, it was possible to comprehend that, in addition to the acquisition of the written language itself, there was a significant understanding of other relevant elements of language, such as the discursive genres which are present in our society, especially the written ones. Thus, in the end of the year, the children were shown to achieve autonomy when choosing a genre in an enunciation. Another trace which must be highlighted is the process by which the children manipulated a word and related it to the context in which they were involved. It was possible to observe that the words of others were dialogically reelaborated within my words of others through a process of utilizing different words of others , thus leading to the creation of my own words . In summary, this study provides evidence that carrying out a work aimed to guarantee the right to the written word for everyone is a viable way of establishing a dialog among unique and free subjects who understand, from the first contacts with writing, the meaning and the sense of the word equality .
Preparação e caracterização de pós e filmes finos cerãmicos de titanato de chumbo e estrôncio obtidos por método químico
(Universidade Federal de São Carlos, 2006-07-03)
Leal, Sérgio Henrique Bezerra de Sousa
;
Varela, José Arana
;
https://lattes.cnpq.br/1807399214239200
xvii ABSTRACT In this work it is approached the preparation of ceramic powders and thin films of strontium-doped lead titanate with concentration of strontium varing from 0 to 100% mol, using a chemical method of synthesis, polymeric precursor method (Pechini). This method allows the sythesis in aqueous medium, in ambient atmosphere, using reactants easily available. In this way, the synthesis condicions were optimized in order to elimanate the formation of secondary phases. The powders ceramic treated in different temperatures under ambient atmosphere was studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD), infrared spectroscopy (FTIR), micro-Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), that allowed the identification of the crystalline phases, lattice parameters and crystallite size. A phase transition from tetragonal to cubic was observed in this system as the stontium concentration increases in the (Pb1-xSrx)TiO3. A pseudo-cubic phase was observed for x=0.5, indicanting the complete solid solubility of the system. Thin films were obtained by using spin coating of the polymeric solution on Pt/Ti/SiO2/Si substrates using a rotation speed of 7600 rpm for 30 s and calcining at 600°C for 4 h. The effect of the substituint ion in the microstructure and morphology of those films was discussed through a systematic and detailed study using XRD, FTIR, micro-Raman spectroscopy, optical microscopy and atomic force microscopy (AFM); where it was verified that addition of strontium in the PT lattice resulted in decrease of avarage grain size of those films.
Conservação in situ de Maytenus ilicifolia Mart. ex Reiss. (Celastraceae) na Floresta Nacional de Irati - PR
(Universidade Federal de São Carlos, 2006-07-04)
Mazza, Maria Cristina Medeiros
;
Santos, José Eduardo dos
;
https://lattes.cnpq.br/8533387365058570
The conservation of biodiversity is a priority and strategic question at world level. During the last decades, the intensive extraction of non-timber species resulted in the loose of biological diversity and degradation of natural forests. The recent expansion of medicinal plants, almost exclusively founded on extractivism contributes to degradation of these species in their natural environment. Maytenus ilicifolia Mart. ex Reiss. ( espinheira-santa ), species from the Sub-Tropical Forests, mainly from the Mixed Ombrophylous Forest (Araucaria Forest), has medicinal properties for treatment of gastrointestinal diseases. It is now listed among the endangered species of the flora of Parana and São Paulo States, in the categories of rare and almost extinct respectively, and has been considered as having priority for protection and sustainable use. The Protected Areas play a fundamental role in the in situ conservation of the biological diversity; however, the composition and importance of the biodiversity distributed in these Areas are not yet well known. There is neither report about in situ conservation of medicinal species in Brazil nor studies about their ecology in the Protected Areas. This study evaluates the phenology, size structure and population dynamics of Maytenus ilicifolia in the Irati National Forest, in order to have basis for its in situ conservation. The Irati National Forest (25°21 S e 50°35 W), a Protected Area of sustainable use, is localized in the municipalities of Fernandes Pinheiro and Teixeira Soares, Parana State. The phenologic study of this species was done in 78 adult individuals, during two years. The intensity of flowering and fructification events were estimated using a scale from zero to four, with 25% in every class. For population size structure, height and diameter were evaluated in five groups of Maytenus ilicifolia between 2004 and 2006, using the Gini coefficient. The dynamics was evaluated using transition matrices for five developmental stages. It was used to estimate the finite growth rate of the population (λ), the stable structure and the reproductive value during ...
Representações de diferentes atores sociais sobre o trabalho: ergonomia e saúde - um estudo de caso.
(Universidade Federal de São Carlos, 2006-07-06)
Bernardino, Mônica Thais Simões Matsukura
;
Truzzi, Oswaldo Mário Serra
;
https://lattes.cnpq.br/5005536921435787
This research is based upon theoretical concepts from Work Ergonomics Analysis, Action-Research and Occupational Health fields. The study approaches the capacitation experience of an Ergonomics Committee at the Brazilian Post-office Company (Empresa Brasileira de Correios e Telegrafos ECT). The objective has been to conceptually comprehend and discuss the possibilities of considering the viewpoint about the work from workers, different hierarchic levels members, and the Ergonomics Comitee in order to elaborate an ergonomics intervention proposal and support the capacitation process. In order to accomplish these goals, different social actors involved with the work developed at the Local Distribution Centers (Centros de Distribuição Domiciliar CDD) such as mailmen, immediate chefs, regional and state managers and central administrators as well as the Ergonomics Committee members have been interviewed and their statements have been analyzed. As result from this analysis it can be inferred that a) the perception about the work reality has a direct relationship with the institutional insertion level of different social actor groups; b) taking in consideration the representation that each social actor group has about the real work performed allows for achieving a broader comprehension on key factors related to work overload and work health harm; c) the Ergonomics Committee s perception on issues related to ergonomics, work and health and the consequent position it has taken, has improved along capacitation process.
A pré-história da linguagem escrita na idade pré-escolar na sociedade letrada: contribuições da teoria histórico-cultural.
(Universidade Federal de São Carlos, 2006-07-06)
Vieira, Rosana
;
Reyes, Cláudia Raimundo
We try, in our work, to analyze if the experience in the scholar society anticipates the process of appropriation of the written language, in its pre-history, in preschool age children. We understand that the scholar society, when promoting the interaction of the child with the writing, in the diverse social situations involving the text carriers, it could anticipate the process of appropriation of the writing during its pre-history, as wrote A.R. Luria. In the elaboration of the written activity, we consider some of the experimental characteristics of the author. We still did a half-structuralized interview with their parents to inquire the mediation cultural context with the writing and the contact with the text carriers, where the children live deeply, in the social situation that they were involved. The results show us that the presence of the text carriers does not guarantee the anticipation of the pertaining periods of training to the pre-history of the writing . However, these carriers, inserted in intentional situations of functional use of the writing, mediated socially, they had taken the child, in the preschool age, to the meaning that accomplishes of the writing in their scholar pre-history context.
ExtraWeb: um sumarizador de documentos Web baseado em etiquetas HTML e ontologia
(Universidade Federal de São Carlos, 2006-07-10)
Silva, Patrick Pedreira
;
Rino, Lúcia Helena Machado
;
https://lattes.cnpq.br/0315640846525832
This dissertation presents an automatic summarizer of Web documents based on both HTML tags and ontological knowledge. It has been derived from two independent approaches: one that focuses solely upon HTML tags, and another that focuses only on ontological knowledge. The three approaches were implemented and assessed, indicating that associating both knowledge types have a promising descriptive power for Web documents. The resulting prototype has been named ExtraWeb. The ExtraWeb system explores the HTML structure of Web documents in Portuguese and semantic information using the Yahoo ontology in Portuguese. This has been enriched with additional terms extracted from both a thesaurus, Diadorim and the Wikipedia. In a simulated Web search, ExtraWeb achieved a similar utility degree to Google one, showing its potential to signal through extracts the relevance of the retrieved documents. This has been an important issue recently. Extracts may be particularly useful as surrogates of the current descriptions provided by the existing search engines. They may even substitute the corresponding source documents. In the former case, those descriptions do not necessarily convey relevant content of the documents; in the latter, reading full documents demands a substantial overhead of Web users. In both cases, extracts may improve the search task, provided that they actually signal relevant content. So, ExtraWeb is a potential plug-in of search engines, to improve their descriptions. However, its scability and insertion in a real setting have not yet been explored.
Abordagem para diagnóstico de problemas em aplicações de E-GOV - um retrato dos municípios brasileiros.
(Universidade Federal de São Carlos, 2006-07-10)
Bittar, Thiago Jabur
;
Silva, Junia Coutinho Anacleto
;
https://lattes.cnpq.br/6200743168568684
In this work, the main theme is to collect data to diagnose problems and formalize solutions in the Brazilian municipal Electronic Government (E-GOV) domain, focusing on G2C (Government to Citizen) at the first moment. In order to do that, this research analyses and relates: the main problems and challenges to promote E-GOV in general terms and in Brazilian cities as well as in cities from all over the world; the Legislation and guidelines of E-GOV project. So, it was developed a methodological approach composed by a group of methods and complementary macro-activities to scale the results understanding up, supporting the building and spreading of a significant, valid and widespread knowledge in this domain. Such macro-activities used to gather the data are: (i) investigating cities information automatically, (ii) contacting the Administrations via a marketing research and (iii) evaluating the sites by inspection in order to validate the diagnosis. Thus, once the problem recurrence is verified and a successful solution is observed, a propitious base of information is configured so that Proto-Patterns can be identified and formalized as a structured and elegant way to document and diffuse the solutions in the context of E-GOV development to cities, relating to the Software Engineering (SE) and Human-Computer Interaction (HCI) domains.
A produção social da cidade. Os discursos legitimadores da segregação sócio-espacial no interior paulista: Ribeirão Preto 1889-1930.
(Universidade Federal de São Carlos, 2006-07-11)
Sousa, Hugo Freitas de
;
Monsma, Karl Martin
Macroinvertebrados bentônicos dos sistemas aquáticos da estação de piscicultura do CEPTA/IBAMA, Pirassununga, SP
(Universidade Federal de São Carlos, 2006-07-21)
Oliveira, Heliana Rosely Neves
;
Strixino, Susana Trivinho
;
https://lattes.cnpq.br/1804083229761186
With the objective to verify the distribution and the taxonomic structure of the benthic macroinvertebrates fauna of water systems (reservoir, fisheries and channels) of the CEPTA/IBAMA (Pirassununga, SP), a study with two types of methodologies was carried out. The samples of the sediment in the reservoir had been carried out with the Ekman-Birge grab, and in the fisheries and the channels with artificial substrate. The assemblages of benthic macroinvertebrates had been analyzed taxonomic and structurally. The larvae of Chironomidae (Diptera) were the main organisms in all the environments. The predominance of Procladius sp. and Djalmabatista pulcher was observed in the two reservoirs. The spatial analysis of the taxa distribution in the depths, pointed out with to major variety of taxa in the less depth regions (< 2m) in the Represa Velha, in contrast of the Represa Nova. At the same time, the average densities of the organisms had been opposing in the two reservoirs, presenting respectively major and lesser values in the intermediate depths (>2<3m). Temporaly, major abundance of macroinvertebrates at the dry season was observed, where major number of individuals occurred, represented mainly for the Procladius sp. and D. pulcher. In the faunistic analysis with artificial substrate, Goeldichironomus maculatus was dominant. There was taxonomic similarity between the assemblages in the artificial substrates in the reservoirs, fisheries and channels. The cluster analysis between the sampling methods, clustering the fauna of the baskets with the artificial substrate in the two reservoirs, and the fauna collected with the Ekman-Birge grab. This result points out with respect to the problematic use of artificial substrate use as a tool to characterize the fauna of a system.
A caminho do rio: um estudo sobre as relações de gênero e meio ambiente entre os pescadores do Alto-Médio Rio São Francisco
(Universidade Federal de São Carlos, 2006-07-27)
Madeira, Thais Fernanda Leite
;
Mancuso, Maria Inês Rauter
;
https://lattes.cnpq.br/3038895593457591
Determinação in situ de fósforo, nitrato e amônio em solo
(Universidade Federal de São Carlos, 2006-07-28)
Menezes, Eveline de Abreu
;
Nogueira, Ana Rita de Araújo
;
https://lattes.cnpq.br/7034773971317045
;
https://lattes.cnpq.br/8849367592224960
The cultures platforms of productivity need to be optimized, owing to provide foods to an enhanced world population. A control of the soil fertility is necessary, in order to be adequately productive without, however, have losses for excess of nutrients, which could cause serious environmental problems. Due to soils and cultures requirements, nitrogen and phosphorus fertilizations are the more important ones. In this work, selective chemical sensors to phosphorus (PO4 3-), nitrate (NO3 -) and ammonium (NH4 +), installed in polymeric probes and their associated instrumentation were evaluated. The evaluation was carried with the addition of 0.1 mol L-1 P-PO4 3- solution to the soil, data acquisition supplied by the probes, collects of soil samples in the region where the probes were installed and determination of evaluated nutrients by conventional laboratory techniques. The PO4 3- amounts were determined by spectrophotometry after the following extraction methodologies: Mehlich-1, Mehlich-3 and ionic exchange resin. The results were compared with the fitted potentials registered by the probes, and the best correlation was obtained with the method of the resin. For evaluation of the probes, constructed with selective sensors to NO3 - and NH4 +, NH4NO3 salt was added directly to the soil. Four probes had been installed; one of them was used as control. Surface and 20-cm soil depth, region where the sensors were located, were periodically collected. The amounts of NO3 - and NH4 + had been determined by spectrophotometry, by using procedure based on Berthlot reaction adapted to a flow system. The results, compared with the potentials provided by the sensors, presented similar changes profiles. Great alterations in the sensors potentials had not been observed after addition of nitrogen fertilization, due to the little percolation of nutrients in the soil profile. The results indicate good response of the sensors, and the potential applicability of these probes to assist the monitoring of soil nutrients, owing the establishment of rational processes in the fertilizers uses by the cultures.
Rodovias em áreas urbanizadas e seus impactos na percepção dos pedestres
(Universidade Federal de São Carlos, 2006-07-31)
Silva Junior, Sílvio Barbosa da
;
Ferreira, Marcos Antonio Garcia
;
https://lattes.cnpq.br/2643134259454260
;
https://lattes.cnpq.br/8480076142039633
This work presents the results of a opinion poll, applied to the inhabitants of an urban area along the BR-050 highway, in Uberlândia MG, carried out to estimate the importance of the impacts originated by the Barrier Effect and its characterization attributes. The Barrier Effect refers to the motorized transportation infrastructure impacts over the non-motorized transport. The method applied to this survey to determine the importance degree of each variable and its attributes of characterization related to the Barrier effect consists of a questionnaire, elaborated according to the Likert recommendations, and with the utilization of the Successive Intervals Method to determine the distance of the elements of a scale. The method which has been considered appropriate and easy to apply, produced satisfactory elements to the proposed analysis. The results show that the highway, inserted in a urban site, limitate the on foot transport for the inhabitants of the surroundings of the highway (effects), resultants of the Barrier Effect. It also was possible to identify the importance of defining attributes of each limitation (causes).
Avaliação da resistência mecânica de argamassas de cimento Portland contendo serragem de couro tratada em meio ácido
(Universidade Federal de São Carlos, 2006-07-31)
Silva, André Luiz Ribeiro Tachard da
;
Morelli, Márcio Raymundo
;
https://lattes.cnpq.br/0172837599844991
Suitable destination of industrial solid wastes that have not well established or completely successful mitigation techniques is nowadays a fundamental important subject, all over the world. In Brazil, one of the most pollution-intensive industries is the tanning skin and processing leather industry. Among its wastes, there is a hazardous chromium-containing waste, named leather shaving, which needs technological alternatives to reintegrate its great quantity generated to materials life cycle. Based on materials engineering concepts, and from the experiences related in bibliography, this work proposes the leather shaving dissolution in phosphoric acid and later incorporation of this new product in Portland cement mortar; changes on the strength of mortar are very important, being the focus of this work. Mortars and cement pastes were made to serve as standards, and treated waste-containing samples were produced to compare the results and to try explaining their causes. The analysis of the experimental results shows that treated leather shaving addition inhibits hydration of Portland cement compounds, due to the phosphoric acid; this retard is disclosed by the increased paste setting time and the mortar mechanical strength development after 91 days, this strength is close to the standard sample one. Porosity remained almost unaltered, and the main microstructural change found was the calcium phosphate phase formation, detected by XRD and SEM. At last, cement matrix was effective at fixing chemically Cr (III), an important result in view of environmental aspects.
Medidas de condutividade na caracterização de complexos inorgânicos: um levantamento bibliográfico
(Universidade Federal de São Carlos, 2006-08-01)
Velho, Rodrigo Garcia
;
Batista, Alzir Azevedo
;
https://lattes.cnpq.br/6469642481998660
In this work was done a review of the data published in inorganic chemistry journals (Inorganic Chemistry and Inorganica Chimica Acta in the years 1973-2005 and 1983-2005, respectively) on values of measurements of conductivity of coordination compounds in organic solvents and water. The main objective of the work was up to date the data collect by GEARY in his paper The use of conductivity measurements in organic solvents for the characterization of coordination compounds published in the journal in 1971 . The data of the conductivity of the complexes were listed o a table according to the solvent used for the measurements in the respective electrolyte and the final propose of the work was to establish a range of conductivity for each type of electrolyte.
Aplicação de técnicas espectrométricas, cromatográficas e quimiométricas na avaliação da autenticidade de plantas utilizadas como fitoterápicos
(Universidade Federal de São Carlos, 2006-08-01)
Daolio, Cristina
;
Ferreira, Antonio Gilberto
;
https://lattes.cnpq.br/3676462220401452
;
https://lattes.cnpq.br/0173677456119225
The use of herbal medicines in the Brazilian market has increased in the last few decades. Therefore, the quality control for herbal products, as well as traditional medicines, is extremely important and for both: the manufactured products and the raw material. However, to guarantee the product s quality implies in an increase of the process costs in an industry. Currently, the quality of herbal extracts is predicted by analysis of selected marker compounds, which are often characteristic chemicals of a specific herb, but that many times do not present any relation with bioactivity. As a consequence, the marker-based approach is an incomplete and unsatisfactory method for quality control of herbal medicines In order to cope with this problem, current developments in improving sensitivity and analytical capacity of known techniques, had made possible the plant s complex extract evaluation. The present work describes an analytical methodology for the phytomedicines catuaba, espinheira-santa and guaco, based on the metabolic profile approach, where the Nuclear Magnetic Resonance techniques, as well as the High Performance Liquid Chromatography, are employed to obtain a fingerprinting of these herbal medicines. Nevertheless, due to the complex spectral data profile (1H spectra and chromatograms) evaluation it was necessary to employ chemometrics. These multivariate methods made possible to extract some relevant information and to prove the authenticity of the analyzed commercial samples. The commercial catuaba samples analysis by HR-MAS NMR/ chemometrics showed be more efficient, when compared with liquid NMR, indicating that the species sold as the phytomedicine catuaba is Trichillia catigua. Whereas, the results obtained for espinheira-santa showed an opposite situation pointing out that the efficiency of the HR-MAS is correlated with the physiological constitution of the plant material analyzed. Beside NMR results, HPLC analysis showed that the majority of the espinheira-santa commercial samples do not employ Maytenus ilicifolia species. The guaco results obtained by both, NMR and HPLC techniques were inconclusive needing the use of a complementary technique. Therefore, the present work also describes the use of the High Performance Liquid Chromatography coupling with Abstract Tandem Mass Spectrometry, by means of SRM experiments, to evaluate some commercial guaco samples. This technique provides the detection of the coumarin 1,2-benzopyrone in all the analyzed samples, due to the SRM high sensitivity, thus certifying its authenticity. The results obtained by Nuclear Magnetic Resonance, High Performance Liquid Chromatography and chemometrics, proved to be valuable tools for the evaluation of complex phytomedicines matrix. In specific cases, where high sensitivity in the analytical method is required, Mass Spectrometry can be used as an additional technique.
Análise do comportamento da fluidodinâmica do leito de jorro com misturas de tamanho de partículas
(Universidade Federal de São Carlos, 2006-08-01)
Bacelos, Marcelo Silveira
;
Freire, José Teixeira
;
https://lattes.cnpq.br/2270677706718167
This research study presents an investigation to quantify the stability of spouting regimes (by pressure fluctuations) and particle segregation level in conical spouted beds operated with a variety of particle combinations with uniform size or size distribution. In the presence of glycerol, a study on the effect of interparticle forces in the conical spouted bed fluid dynamics behavior with inert particle mixtures was also employed. Data show that, at a standard deviation from pressure signals of 50 Pa, in beds composed of inert particle of uniform size or size distribution stable spouting regime can be achieved. Moreover, the analysis of segregation indexes revealed that particle segregation becomes less pronounced as dpL/dpS is reduced from 2.85 to 1.98 and bed height is increased from 0.105 to 0.195 m. When glycerol is added into the bed, the results show that the dimensionless minimum spouting velocity (vmj/vmj0) does not change significantly with increase in glycerol concentration for the reference mixture. However, for all other mixtures of dpL/dpS > 1.98 employed, vmj/vmj0 increases with increase in the glycerol concentration into the bed, and this increase is more pronounced for flat and binary mixtures. The dimensionless of minimum spouting pressure drop (∆Pmj/∆Pmj0) decreases with increase in the glycerol concentration for all mixtures used. The application of a theoretical analysis, predicting the interparticle forces, shows that the change in minimum spouting condition as glycerol concentration increases can be explained by the magnitude of these forces.
Origem dos momentos magnéticos localizados em ligas de cromo com metais de transição por oscilações de Friedel
(Universidade Federal de São Carlos, 2006-08-02)
Souza, Paulo Eduardo Narcizo de
;
Oliveira, Adilson Jesus Aparecido de
;
https://lattes.cnpq.br/4640148190073166
;
https://lattes.cnpq.br/2067881167853475
The fundamental magnetic properties of chromium and its alloys Cr(1¡x)Nb(x) and Cr(1¡x)V(x), were investigated with the aim to achieve a better comprehension about the nature of the spin density waves. Was dened the edge between the AF1 and AF2 phases on the Cr(1¡x)Nb(x) alloys as function of niobium concentration. Using x-rays di®raction techniques was studied de formation of antiferromagnetic domains in the surfaces with [001] direction of chromium samples. As observed, cooling the sample under applied magneticeld do not create new magnetic domains, actuating only on its reorien- tation. The magnetic history of sample does not in°uence the surface magnetic domains formation, been an exclusive property of the sample surface crystalographic orientation. Was observed the formation of localized magnetic moment on paramagnetic phase of Cr(1¡x)Nb(x) alloys. This phenomenon early studied in Cr(1¡x)V(x) alloys, shown important qualitative di®erences which are explained on Friedel oscillations picture generated by impurity atoms. Was realized x-rays di®raction experiments which provided evidences of the existence of Friedel oscillations in Cr(1¡x)V(x) alloys.