Browsing by Issue Date, starting with "2000-03-03"

Filter results by year or month

Now showing 1 - 20 of 23462

Desenvolvimento e caracterização de blendas Poli(tereftalato de etileno) - PET/ Poli(naftalato de etileno)- PEN
(Universidade Federal de São Carlos, 2000-03-03)
Nunes, Edilene de Cássia Dutra
;
Agnelli, José Augusto Marcondes
;
https://lattes.cnpq.br/7592090152400440
;
https://lattes.cnpq.br/8361322278754916
The scientific and technological development of food packaging polymers has increased considerably over the last years, especially in relationship to packaging for beverages such as carbonated soft drinks and beer. As for carbonated soft drinks polyethylene terephthalate PET has been the most widely investigated polymer in virtue of its favorable intrinsic properties, and in recent years polyethylene naphthalate - PEN has attracted increasing interest as a result of its superior performance in relationship to PET in applications that demand higher technical requirements, however its major drawback is the high cost. One way of making PEN applications economically feasible is by blending with PET. Nonetheless, as these polymers are immiscible, conditions of process that enable an effective mixture should be looked for and, in some cases mixing of polyesters may lead to transesterification which favors miscibility between the polymers. In the current work four polymer blends were prepared from two types of PET and two types of PEN, both supplied by Eastman Chemical Company and Mitsui Co. Ltd. The premixing and processing conditions were studied, assessing the best combinations of pressure, temperature, cooling time. After specimen preparation all blends were characterized as to structural (FTIR, NMR), thermal (DSC, TGA, DMTA), mechanical (tensile test) and thermomechanical (HDT, Vicat) properties. NMR enabled confirmation and quantification of the transesterification reactions between the blend constituents responsible for blend miscibility and compatibility, notably the PET Eastman / PEN Eastman blend, which was the combination decided upon to be tested on industrial scale by injection molding of the parisons and posterior blow molding of 600 ml bottles, these were characterized in DCS, NMR and as to gas permeability.
A formação do educador reflexivo: um olhar sobre a construção de sua prática pedagógica
(Universidade Federal de São Carlos, 2000-03-15)
Lima, Paulo Gomes
;
https://lattes.cnpq.br/5109357037661496
A finalidade deste artigo, longe de apresentar “receitas prontas” para a reversão de intervenções pedagógicas sem planejamento, preocupa-se em problematizar a formação do educador do ponto de vista de suas proatividade reflexiva. Esse exercício dá-se no decorrer da formação inicial e dos processos formativos ao longo da carreira, como veremos neste artigo.
A consciência na primeira tópica freudiana
(Universidade Federal de São Carlos, 2000-03-23)
Cossu Junior, Franco
;
Monzani, Luiz Roberto
;
https://lattes.cnpq.br/2036732603638197
;
https://lattes.cnpq.br/8871513367560163
The principal aim of this entire work is to clarify the theorical statue about the counsciousness concept in the first freudian topography. In spite of the Uncounscious discovery and its central importance in the mental apparatus theory to the comprehension about pathologies as much as normality, the counsciousness never let to be a Freud`s constant worry, since the Studies on Histeria until the Metapsychology elaboration. If the counsciousness phenomenon, which is no longer central, may be considered an efect of surface and no more equivalent to the general psychism, it doesn`t renounce to be, although, the only way to the knowledge of the uncounscious phenomena.
Lacan e o estruturalismo
(Universidade Federal de São Carlos, 2000-03-23)
Felizola, Maria Cristina Merlin
;
Simanke, Richard Theisen
;
https://lattes.cnpq.br/5431145327759147
The present work has arisen of the need to understand the Lacan statement "the unconscious is structuralized as language". With this affirmation Lacan has pointed to two important directions: His incursion to the structuralism movement and the adoption of the Linguistics as reference. First we feel the necessity to know the structuralism movement and its bigger contributors. The structuralists have had much concern in searching a model which could explain the biggest possible number of aspects of a phenomenon, in a simpler and economic. In relation to the Linguistics the contribution came from the Fonology, this served as model for considering the terms in its internal relations, for introducing the structure notion and also searching the general laws construction. The formalization degrees that the Linguistics reach was such that it started to serve as influence for others disciplines of human being sciences, in their intention to ascend to the category of rigorous sciences. The structuralism brought a new method to approach the societies and the man. The unconscious, the primitive society and everything that had been depressed in the occidental History has found a place in the movement that searched the grammar of the human being thought.
Miragem da conquista: a religião na teoria freudiana da cultura
(Universidade Federal de São Carlos, 2000-03-24)
Carone, André Medina
;
Simanke, Richard Theisen
;
https://lattes.cnpq.br/5431145327759147
;
https://lattes.cnpq.br/5392166032777488
Indicadores de sustentabilidade urbana: as perspectivas e as limitações da operacionalização de um referencial sustentável
(Universidade Federal de São Carlos, 2000-04-05)
Silva, Sandra Regina Mota
;
Shimbo, Ioshiaqui
;
https://lattes.cnpq.br/6315114291031702
;
https://lattes.cnpq.br/9973870842834947
The complexity of the problems deriving from urban environments has required a deeper and more integrated understanding of the reality of these environments as an essential step toward solutions. The main purpose of this study is to investigate the applicability of principles of sustainability in the process of monitoring the socioenvironmental conditions of this medium. To gain a better understanding of the ideas surrounding the perspective of sustainability, the different meanings ascribed to the term, as well as the complementary issues and aspects that interact in this world of considerations are discussed. Thus, basic conceptual elements were sought that would contribute to build aproper definition for use within the context of this work, which in turn allowed for an outline to be made of its essential characteristics and general guiding principles that were then employed to analyze a given set of indicators. Different reflections and proposals regarding the instruments used to evaluate urban conditions were examined to identify a set of variables defining the basic characteristics of projects and implementation. A critical systematization of three previously selected experiences the Agenda 21 Indicators, the Seattle Indicators and the Belo Horizonte Urban Life Quality Index led to the elaboration of an analysis based on the general principles of sustainability and on the set of variables existing in the process of creating, formulating and monitoring these indicators. This analytical repertoire allowed for a definition of the potential represented by these instruments, offering the basic references for its development and implementation in different contexts.
Limnologia comparativa de três lagoas neotropicais da Bacia do Magdalena Médio Santandereano (Colômbia), com ênfase no estudo da diversidade da comunidadezooplanctônica e sua relação com a dinâmica hidrológica do sistema regional
(Universidade Federal de São Carlos, 2000-04-14)
Diaz, Rosa Aura Gavilán
;
Tundisi, Takako Matsumura
;
https://lattes.cnpq.br/7789295211200946
Few studies have been developed regarding zooplankton diversity in Neotropical Region, particularly in Colombia. Regarding the diversity in the Tropical region still there are a great controversy, despite the relevance of this community as indicator of climate or hydrological, physical and chemical changes. A limnological study was performed during the period between January, 1998 and January 1999, in three shallow lakes ( ciénagas ) belonging to Rio Magdalena Basin, Middle Santandereano,-Colômbia. At monthly intervals a set of physical, chemical and biological variables were measured in a sampling station at the central region of the lakes. The effects of rainfall and water level on Shannon-Wiener zooplankton diversity index were analyzed. Also analyses of taxonomical composition and relative abundance of zooplankton community as a whole or for the Rotifera, Cladocera and Copepoda were performed showing differences among the lakes. A similar thermal structure with microstratification in surface layers and gradual decreases with depth was observed. Maximum temperature value found was 38º C in the surface and 26.8ºC at the bottom. Physical and chemical conditions varied along the hydrological cycle, although there was not a defined pattern except regarding nutrient concentrations that was observed to be higher in the lowest water level and suffering dilution in the wet period for all lakes. The highest values of Chlorophyll a (229.2 µg.L-1) and net primary production (3203 mg C m2d-1) were found in Ciénaga of Chucuri Lake. It appears that there is an inverse relationship between total zooplankton densities and chlorophyll a concentrations. The highest richness of taxa was observed in Ciénaga El Llanito. Rotifers had the highest annual numerical relative abundance and also the highest taxonomical richness in all lakes, throughout the hydrological cycle. There appears to be an alternation in the dominance of species for each particular group of zooplankton in the three ciénagas However it does not appear to be a succession pattern. The highest Shannon-Wiener índices were obtained for Ciénaga de Paredes (4.12 bits.ind-1) and the smallest for Ciénaga de Chucurí (1.24 bits.ind-1) and simultaneously a higher equitability was found, suggesting that the highest diversity indices were related to uniformity. There was no correlation found among water level fluctuation and zooplankton density as a whole, but this exists when the component groups were considered alone, as it was found for Cladocera in Ciénaga de Paredes. The absence of correlation among zooplankton diversity indices and water level fluctuations suggest that each group probably responds to multiple interacting factors in each lake.
Processos estocásticos de reação e difusão na rede e cadeias quânticas
(Universidade Federal de São Carlos, 2000-06-02)
Mendonça, José Ricardo Gonçalves de
;
Alcaraz, Francisco Castilho
;
https://lattes.cnpq.br/9538405812117662
;
https://lattes.cnpq.br/8792749813872106
In this work we investigate some reaction-difusion stochastic processes on the lattice. In particular, we determine the universality classes of critical behavior of a nonequilibrium surface growth process and of the basic contact process. Our main tools of investigation are exact numerical diagonalizations and finite-size scaling ideas. We also present an application of the Bethe ansatz in the exact diagonalization of the infinitesimal generator of a di_usion process of particles without exclusion known as the zero range process.
Caminhos da universidade rumo ao século XXI: pontos e estratégias para a sua orientação na visão de educadores brasileiros
(Universidade Federal de São Carlos, 2000-08)
Lima, Paulo Gomes
;
https://lattes.cnpq.br/5109357037661496
A principal preocupação desse estudo é, através das reflexões nele contidas, apontar caminhos que poderão contribuir para que as nossas universidades, face à inevitável globalização, possam se instrumentalizar de forma coesa, de modo a cumprir sua missão na formação e transformação do homem. Para tal, organizamos esse trabalho sobre a universidade partindo de sua gênese, passando pelo momento atual e chegando até as perspectivas que se tem da universidade pretendida para o próximo milênio; para isso foram coletados dados que permitiram analisar alguns de seus problemas e, através dessa análise levantar possíveis soluções frente ao emergente século XXI.
La formación del educador reflexivo: notas para la orientación de sus prácticas
(Universidade Federal de São Carlos, 2000-09)
Lima, Paulo Gomes
;
https://lattes.cnpq.br/5109357037661496
La práctica pedagógica es el termómetro que esclarece la realidad del aula, revelando inequívocamente la relación de compromiso (o la falta de él) del educador con sus estudiantes y con la educación. Nótese que no usé la palabra “involucramiento”, pero sí “compromiso”, pues la primera denota una relación superficial, “un entregarse por la mitad”, “un jugarse” sin creer verdaderamente en su misión, en sus efectos reales para la transformación del hombre y del mundo; “para conformar el sentido de la obligación que la docencia conlleva”. La segunda palabra por la cual personalmente tengo preferencia, infiere la acción concreta de “abrazar la educación totalmente”, de “rendirse a ella”, no sólo por el sentido de la obligación de la profesión o por el significado literal que la propia palabra “compromiso” trae consigo, sino porque establece una perennidad que es la fuerza motriz del pensar y vivir de la educación.
Controle da volatilização de inibidores voláteis de corrosão através de suporte de alumina
(Universidade Federal de São Carlos, 2000-10-20)
Panza, Luciana Paula
;
Kuri, Sebastião Elias
;
https://lattes.cnpq.br/6842072916153866
;
https://lattes.cnpq.br/6443072583987507
During the process of the fabrication, storage and transport of equipments, the control of metallic corrosion can make though vapor phase corrosion inhibitors (VCI). These inhibitors are, generally, organic salts deriving from powerless acids and moderate powerful bases and posses, how principal characteristic, high vapor pressure, that for them confer great volatily. Meantime, the majority of the volatile inhibitors utilized contain in these compositions nitrite ion that accordant the new ecologic legislation, is a harmful agent to nature and human. This work discusses the principals polemics created to ISO 14000 and propose a comparative study between traditionally and news inhibitors free of nitrite ion. So, the VCIs were submitted to the thermogravimetric analysis tests and were verify the mass detriment with the changes of the temperature. Following, isothermic tests was realized and was computed the linear volatization velocity constants to the different inhibitors. The efficiency of the inhibitors was verified through the systems containing the different VCIs and the accompanying of the corrosion happened since the beginning for the optical microscopy.
Os efeitos da adaptação do PECS associada ao Curriculum funcional natural em pessoas com autismo infantil
(Universidade Federal de São Carlos, 2000-11-16)
Walter, Catia Crivelenti de Figueiredo
;
Almeida, Maria Amélia
;
https://lattes.cnpq.br/4061818490832341
Communication disorders in persons diagnosed with autism, generally are severe and bring difficulties to their interpersonal relationships, putting them apart, being not comprehended by the majority of other people. The main objective of this study was to evaluate the effects of the adaptation of the Picture Exchange Communication System (PECS) applied in the context of a natural functional curriculum (adapted PECS) in the communication of persons diagnosed as autistic, who do not presented oral language and/or functions speech at the beginning of the study. As a secondary objective, the study had the intention to verify if the adapted PECS would help the participants to begin to use of speech. The study was conducted at Centro Ann Sullivan do Brasil (CASB), located in Ribeirão Preto City São Paulo State. In order to verify the effects of the intervention, an AB simple subject research design was applied and replicated within four boys with ages varying from 5 to 8 years old, diagnosed as autistic. The study involved two phases: baseline and intervention. In order to train the 5 phases of the adapted PECS, the PCS (Picture Communication System) pictures was used. The training and data collection sessions were held during 2 years. The results showed that all participants presented changes in their communicative behavior and acquired an expressive vocabulary in some words, some sounds and in the use of pictures, that varied from 25 to 61, all being used with communicative function. The obtained data suggests that the use of pictures with interaction and solicitation objective of something very much desired, seems to contribute to the emission of speech, sounds and gestures, used with communicative function by the participants. However, other studies must be encouraged, as well as the adapted PECS extension to persons with different diagnoses, who are able to benefit from any alternative communication system. The study concludes, since the PECS communication system has a basic element the interested picture exchanging by the participants through an interactive action, could contribute, in the future, to the inclusion process, not only at school environment, but also to home and community
Estudo de pós cerâmicos de PbTiO3 utilizando-se o método dos precursores poliméricos
(Universidade Federal de São Carlos, 2000-11-30)
Paris, Elaine Cristina
;
Longo, Elson
;
https://lattes.cnpq.br/9848311210578810
THE STUDY OF PbTiO3 (PT) CERAMIC POWDERS USING THE POLYMERIC PRECURSOR METHOD was started by the preparation of a precursor solution of metallic cations. Citric acid was used as quelation agent and ethylene glycol as esterification and polymerization agent. This solution was submitted to thermal treatment at temperatures about 300°C for the pyrolysis of the obtained polyester. PT crystalline powders were obtained starting from amorphous precursors, varying the calcination conditions as the temperature, the time and the furnace atmosphere. The evolution of the crystallization process of the PT was accompanied by X-ray diffraction (XRD), Raman spectroscopy and infrared spectroscopy (FTIR). It was verified that the beginning of the crystallization of the PT occurs at a temperature below the Curie temperature of the material (~ 490°C). Heat treatments for one hour at 400°C yields PT crystalline and free of secondary phases. It was observed that the formation of the PT phase takes place without the formation of an intermediary carbonate phase that can occur in perovskites obtained by the polymeric precursor method. It was verified that there was no formation of pyrochlore or fluorite intermediary crystalline phase, and the only intermediary phase found was cubic PT in some calcination stages. This indicates that the polymeric precursor method provides the homogenization of the ions at the molecular level, during the synthesis process. Aiming at a better understanding of the crystallization process, a comparison was performed between the amorphous and crystalline powders by means of X-ray absorption, using EXAFS (Extended X-Ray Absorption Fine Structure) and XANES (X-Ray Absorption Near Edge Structure) spectra. It was thus verified that the amorphous powders present a short distance structure formed by sixfold oxygen titanium coordination coexisting with fivefold oxygen titanium coordination. Photoluminescent property at room temperature was detected in the amorphous powders. It was verified by reflectance spectra the presence of a tail and of optical exponential borders which are characteristic of amorphous semiconductors. It was also verified that these tail and borders are sensitive to the temperature and to the time of calcination. With the increase of the degree of crystallization of the material and the consequent ordering of the crystalline phase, this luminescent property disappears. By means of theoretical calculations it was possible to verify that the amorphous powder induces electronic levels in the area of the band gap of the material. This fact favors the recombination of the electron-hole pair, which is possibly the responsible for the photoluminescence.
Estudo da influência dos óxidos de Mn, Co e Cr nas propriedades varistoras do sistema SnO2Nb2O5
(Universidade Federal de São Carlos, 2000-12-01)
Bacelar Júnior, Wiss Kraw
;
Silva, Elson Longo da
;
https://lattes.cnpq.br/9848311210578810
Aiming at obtaining SnO2 based varistor systems with a high degree of non linearity, new varistor compositions were studied, by means of doping the known SnO2.Nb2O5.CoO system with Cr2O3 and MnO2, as well as changing the CoO content. Processing parameters, such as sintering temperature, cooling rate, heat treatment atmosphere and composition, were analyzed, assessing therefore the specific role of dopants in the microstructural and electrical properties of a SnO2 varistor system and also optimizing the doping levels. The systems were sintered at different temperatures and cooling rates, aiming at obtaining better densification and electrical properties. X-ray diffractograms indicate the presence of a single phase. However the micrographs obtained by SEM showed the presence of phases segregated at the grain boundary region, and also revealed very porous surfaces, mainly in the systems presenting high manganese concentration. X-ray spectroscopy was used to anlyze the composition of these segregations, indicating the presence of "Mn, Co, Cr and O" in this region. I-V measurements were carried out and the best varistor response was from the system containing 1 mol% cobalt. The systems with higher manganese concentration presented smaller coefficients of non-linearity and also the addition of chromium oxide highly increased the tension of rupture. Analyses of the electrical measurements of the samples, carried out after heat treatment at oxydizing and reducing atmospheres suggest that the oxygen adsorbed at the grain boundary interface is the main source of charge carries, responsible by the non-linear behavior of the SnO2 based varistors.
Influência do processo de usinagem na resistência à fadiga de laminados unidirecionais de epóxi/fibra de carbono
(Universidade Federal de São Carlos, 2000-12-15)
Cervini, Alex Ricardo
;
Lucato, Dawilson
;
https://lattes.cnpq.br/8988121855676365
;
Hage Júnior, Elias
;
https://lattes.cnpq.br/1240692926327687
Carbon fiber-reinforced polymer matrix composites exhibit a high strength-to-weight ratio, standing out for their excellent mechanical properties and widespread application in structurally demanding sectors such as the aerospace industry. Although these materials are often manufactured close to the final geometry of the component, machining operations are still required to achieve adequate dimensional and surface finishing. However, such processes may introduce structural damage capable of compromising the mechanical performance of carbon/epoxy composites. In this work, the influence of form-profile machining on the mechanical behavior of carbon/epoxy composites reinforced with continuous unidirectional fibers was investigated. It was observed that the surface integrity of the specimens was affected by the machining process, resulting in defects such as fiber cutting and exposure of free fiber ends without effective load transfer capability in the machined regions. The experimental evaluation focused on the fatigue behavior analysis of specimens machined transversely to the fiber orientation, with fatigue strength being the main investigated property. The analyzed material consisted of a carbon/epoxy composite manufactured with approximately 60% volume fraction of continuous unidirectional fibers. Fatigue tests were performed using the rotating bending technique with testing equipment developed by Tatnall Krouse. Surface integrity proved to be a determining factor in the fatigue performance of the material.
Análise comparativa de programas de habitação social em três municípios no interior do Estado de São Paulo realizados em regime de mutirão: estratégias de atuação dos atores sociais envolvidos
(Universidade Federal de São Carlos, 2001-02-28)
Kageyama, Carloline Vitti
;
Shimbo, Ioshiaqui
;
https://lattes.cnpq.br/6315114291031702
;
https://lattes.cnpq.br/8729975832167341
The issue of housing in Brazil was redefined in the 1990’s within the current context of administrative decentralization and the increase in power at the local level, the widening of participation and the extent to which civil society is organized, and the closing down of state organs and institutions such as the BNH which provided support for social housing projects. Within this context, the number of municipal programs for housing development has increased, particularly in small and medium-sized cities. The hypothesis which guided this research was that the social actors involved in housing programs in the inland municipalities of the state of Sao Paulo (local government officials, organizations of future homeowners, political parties, technical advisors, unions, the community, etc.) exercise differing degrees of influence during each phase of the construction process which are specific to each of the housing developments, thereby reflecting distinct general strategies. To test this research hypothesis, three recent housing programs were chosen (Franca, Jaboticabal and Monte Alto) with the aim of identifying the social actors responsible and their degree of influence for the various phases in the process of the housing development. The method used consisted of a bibliographic review of the literature; the conduction of interviews of the social actors involved in the processes, based on a previously defined set of questions; and the organization and analysis of the data obtained.
Padrões para aquisição de softwares SIG por administrações públicas municipais
(Universidade Federal de São Carlos, 2001-03-02)
Volpi, Edmilson Martinho
;
Röhm, Sergio Antonio
;
https://lattes.cnpq.br/7332654261230826
Geographic Information Systems are becoming indispensable tools for the Municipal Public Administration manages its activities more eficiently. As all new technology, the Urban GIS also lacks of an efficient methodology for its implantation, since each object of study (City Halls) possess distinct realities and proper particularitities. This paper makes initially a bibliographic revision walk throught the concept of Geographic Information Systems, and on some methodologies of implantation of Urban GIS already developed, focusing in the process of evaluation and acquisition of the GIS software, inside the methodology of implementation. One reveals here, the importance of the software´s question in the Urban GIS implantation. This work tries to analise the functions that a specific GIS software must have to attend the necessities of a Municipal Management, suggesting some important caracteristics to the success of the implantation of this tecnology in Municipal applications, that are not always considered. These caracteristics refer not just to technical aspects of GIS software, but to its operational items, like: software support, operational system, training, software documentation, registration sites, among others. Finally, its is shown that the process of the GIS choose to urban applications must consider, besides the technical aspects, the operational aspects, guarantying this way that the software be more efficiently implanted and used by technical group for generation, maintenance and distribution of geographic information in the city where the GIS project will be implanted.
Propriedades elétricas, estruturais e magnéticas de supercondutores hole-doped e electron-doped dos tipos YBa2Cu3O7-d, Pr2-XCeXCuO4-y e Sm2-XCeXCuO4-y
(Universidade Federal de São Carlos, 2001-03-23)
Lanfredi, Alexandre José de Castro
;
Moreira, Fernando Manuel Araújo
;
https://lattes.cnpq.br/1809254923092721
;
https://lattes.cnpq.br/6882548794489901
The search for new methods to understand the mechanisms associated to superconductivity request novel experimental techniques, as well as materials with different characteristics. In this work, we report results obtained from electron-doped superconducting samples, of the form Ln2-xCexCuO4-y (where Ln = Pr and Sm). These materials are considered high-temperature superconductors (HTS) even for their low values of the critical temperature, TC, of the order of 25 K. These materials are of great interest since they show striking properties when compared to hole-doped materials, like YBCO. Some of these interesting properties observed in electron-doped superconductors are the apparent s-wave symmetry of the order parameter, and normal-state resistivity proportional to T2, while for hole-doped, the symmetry of the order parameter is d-wave and the normal-state resistivity is proportional to T. Therefore, in this work we have performed transport and magnetic experiments on Pr2-xCexCuO4-y (PCCO), Sm2- xCexCuO4-y (SCCO) and YBa2Cu3O7-d (YBCO) thin films samples. They were prepared by Prof. Dr. Fernando M. Araújo-Moreira using pulsed laser deposition (PLD) technique during his post-doc at Center for Superconductivity Research/CSR-University of Maryland in College Park/MD/USA. Their structure was characterized by using the x-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) with microanalysis (EDX-Energy Dispersive Analysis by X-ray). However, the magnetic characterization of those materials was the most important step of this work. To do that, we have built the experimental system to measure the magnetic penetration depth, ë, and the AC magnetic susceptibility, ÷. By determining the behavior of ë(T) is possible to know the symmetry of the order parameter associated to each material under investigation. The magnetic characterization of both materials was completed using a SQUID magnetometer to obtain the magnetic susceptibility data, ÷AC (T, hAC). Through these results we have obtained the average critical current density dependence with temperature, , associated to the critical state model characteristic of each material. The experimental system, projected and constructed during this work, allows the simultaneous determination of both ë(T) and ÷(T).
Análise de padrões e processos no uso do solo, vegetação, crescimento e adensamento urbano. Estudo de caso: município de Luiz Antônio (SP)
(Universidade Federal de São Carlos, 2001-03-30)
Oliveira, Carlos Henke de
;
Santos, José Eduardo dos
;
https://lattes.cnpq.br/8533387365058570
Este estudio buscó la identificación de padrones y procesos relacionados con el uso del suelo, vegetación, crecimiento y adensamiento urbano en la ciudad de Luiz Antônio (SP-Brasil). Se usaron fotografias aereas de pequeño formato (FAPF) y técnicas de clasificación supervisionadas, que agregados al conocimiento del investigador, posibilitaron la integración de algunos princípios de fotointerpretación en la digitación de imágenes. La metodología incluyó también el uso de operadores contextuales que permitieron generar una detallada carta del uso del suelo, posibilitando el análisis basado en las geometrías euclidianas y fractal. También fueron integrados a la investigación, datos provenientes de los satélites Landsat y Spot. Fue demostrado en los resultados que el Índice de Normalizado de las Diferencias en la Vegetación (INDV-Landsat), estuvo altamente relacionado com el uso del suelo, siendo entonces una alternativa para una rápida evaluación de la calidad de las unidades de paisaje com dimensiones de 0,5 ha. A través de la geometría fractal, fue evidente una asociación entre el diseño urbano y la cantidad y tipología de la vegetación, con posibles implicaciones en la calidad ambiental y calidad de vida. Luiz Antônio es una ciudad con deficit en relación tanto a la vegetación de propiedades particulares, como a la vegetación viaria. Aunque las áreas residenciales son las que contribuyen con la mayor parte de la cobertura vegetal en el área urbanizada, la proporción del componente arbóreo/arbustivo, es apenas de 5%. Por outro lado, las áreas públicas verdes, presentan 54,4% de la cobertura arbórea/arbustiva, y son las responsables por aproximadamente 25% de la cobertura arbórea/arbustiva del total del área de estudio. Se obtuvo un Índice de Áreas Verdes (IAV) de 14,9 m2/habitante. La disponibilidad de área edificada por capita es de 37,8 m2/habitante, y no hay indícios de superlotación de habitación. Pero el mayor desafío parece estar relacionado con el ecuacionamento de un modelo de adensamiento que modere la taza de impermiabilización del suelo. El análisis conjunto de muchos descriptores de la calidad urbana, mostró padrones y procesos relativos a la densificación de las estructuras urbanas, al desarollo de la vegetación y al diseño urbano, y a un gradiente natural/rural/urbano. Finalmente, este estudio permitió el análisis de las posibilidades y limitaciones para la expansión urbana de la ciudad de Luiz Antônio.
Cristalização e sinterização de bio vidros do sistema Na2O-CaO-SiO2-P2O5
(Universidade Federal de São Carlos, 2001-03-30)
Leite, Magda Lauri Gomes
;
Zanotto, Edgar Dutra
;
https://lattes.cnpq.br/1055167132036400
;
https://lattes.cnpq.br/4754087297527153
The objective of this work was to study crystallisation and sintering of Bio-glasses of Na2O CaO SiO2 P2O5 aiming at the improvement of the mechanical properties. In order to study the development of glass-ceramics in this system, the effects of the addition of different percentages of NaF, Fe2O3, Li2O, ZrO2, TiO2 and WO3 on the behaviour of crystallisation of the glasses were studied using DSC. The results show that amongst the additions that were tested only Li2O caused increased volumetric nucleation rate. Different melting techniques were tested to obtain glasses with different concentrations of OH-. Although glasses with different contents were obtained successfully, there were problems to homogenise them. The direct extrusion technique was used to produce glass-ceramics with texture. Albeit the technique was efficient with several other systems, the results obtained in the present word showed that the glass-ceramic produced from the extruded glasses did not have the same symmetry that was showed by the glasses that were not extruded. The difficulties in sintering, related to the process of crystallisation, were analysed for two compositions of bio-glasses. Two new crystalline phases, which had not yet been observed in this system, were identified in the studies of sintering. Experimental data showed that superficial crystallisation has strong influence during the process of sintering for both glasses tested. It was not possible to obtain sintered bodies with relative density superior to 0.94 for the experimental conditions that were used. The use of the model that simulates the sintering of the glass proved to be useful to simulate the real effect of each parameter in the process, although it overestimated the ability of sintering of the compositions that were used. The use of this model can facilitate the process of searching solutions for a more efficient sintering process. Using the technique of FTIR, the studies of bioactivity of both glass and glass-ceramic powders revelled higher level of bioactivity for finer powders, and which contained phosphorus in their compositions. It was also verified that whilst total crystallisation hinders the formation of the layer of HCA, partial crystallisation seems to have beneficial effect in the process.