Teses e Dissertações defendidas fora da UFPA

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/7305

Teses e Dissertações defendidas fora do âmbito da Universidade Federal do Pará cujos autores(as) sejam servidores(as) técnicos administrativos ou docentes da UFPA

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Agora exibindo 1 - 12 de 12

Acesso aberto (Open Access)
O ambiente deposicional da Formação Carajás e uma proposta de modelo evolutivo para a Bacia Grão Pará
(Universidade Estadual de Campinas, 2003-08-20) MACAMBIRA, Joel Buenano; SCHRANK, Alfonso; http://lattes.cnpq.br/5381945062567191
The large Carajás iron ores belongs to the Carajás fonnation, which is a 1 00-400m thick banded and laminated iron formation Gaspilite ), located at Pará state in North Brazil. This almost continuous formation outcrops for at least 260km, in 60 ore deposits, distributed in three main ridges, São Felix, Leste and Carajás. The last one is a sinformal structure sub-divided in South and North ridges. This work was carried out on detailed mapping, stratigraphic raising and petrographic, geochemical, isotopic and geochronological sampling of the North ridge, where the mining activity is currently running and bench and drill-core are available. Leveis ( 4 J.Ul1 to 3 cm) composed by chert or jasper alternated with magnetite-maghemite-hematite was deposed between 2,754 and 2,744 Ma (22m/Ma) at depths of 100-200m, locally affected by bottom currents. This hydroplastic chemical sediments precipitated by supersaturation (Si) and oxidation (Fe) from upwelling waters where the base was richer in hydrothermal source waters (LREE=6,66; Eu*=3,54; (La/Yb),=l,52) than the top (I:REE= 3,89; Eu*=3,18; (La/Yb),==,66). Besides, the major elements content have more variability at base than top. The Carajás jaspilite have twice Ga (2lppm), Bi (6ppm), Pb (18ppm) and seven times Sb (7ppm) than the world average for similar rocks. The Fe oxidation may have be promoted by organic activity, attested by delicate double wall spherulites and kerogen preservation in siltstones of a light younger unit. Local hydrothermal carbonatization has affected the jaspilite producing 813C mean of -4.3%opoa and two groups of 8180 (+24,9 to +15,4 and +12,8 to +6,6%osMow ). Otherwise, metamorphic imprints on this rocks are minimal. Regional work, bibliographic compilation and correlations of the Carajás formation with overlying units ofBahia and Azul mines leaves to propose a evolutionary model for the Grão Pará Basin, initiated as a intracontinental rifting stage, marked by crusta! contaminated tholeiitic basalt volcanism (2.76 Ga- U-Pb zircon ages). The second stage was the deposition ofthe Carajás formation over a wide, quiet marine continental she1f, in:fluenced by upwelling of Fe-Si rich waters. In a third stage, the last was recovered by volcanics associated with clastic sedimentation (2.74 Ga- Pb-Pb zircon ages). The fourth stage comprises the installation of another continental shelf environment, where clastics and carbonate rocks has deposed (2.68 Ga - U-Pb zircon ages). Basin inversion and fluvial deposition closes the evolution.
Acesso aberto (Open Access)
Análise do escoamento da soja brasileira através da simulação a eventos discretos
(Universidade Federal de Itajubá, 2017-10-16) LOPES, Harlenn dos Santos; LEAL, Fabiano; http://lattes.cnpq.br/4677862183830898; LIMA, Renato da Silva; http://lattes.cnpq.br/9161092505168234
Brazil, since 2013, is the largest exporter of soybean in the world. In 2016, Brazil exported 51.58 million tons of soybeans. This value corresponds to approximately 40% of the quantity exported worldwide. Even with lower production costs, the competitiveness of Brazilian soybean declines when the product get on the Brazilian logistics network, facing challenges to drain the production. This paper aims to present the construction and application of a simulation project to support strategic decisions of the Brazilian soybean logistics through the simulation of discrete events. The paper's contribution is due to the use of simulation of discrete events applied to a logistic system, with a greater level of comprehension studied and the high number of interrelated variables. For the study, Brazil was divided according to its soybean production, which results in 19 producing areas coming from a minimum level of microregions. These regions are the origins of the system. For each source, 20 routes from North to South of the country were designed, destined to the current soybean export ports, by the main transport axes, either constructed or projected. The decision-making process is based on the costs of the routes and the availability of the ports. The final destinations are the ports of Shanghai and Hamburg. The model was validated, and adequately represents the studied system. A number of 39 scenarios were simulated for the system, divided in 13 scenarios per year, considering projections for 2015, 2017 and 2026. Operational analyzes of logistics configuration and comparative analyzes based on actual costs are performed. At the end of the simulations, scenarios 1, 2, 6 and 7 are the alternatives that best reduce the logistic costs of the studied system and that the railroads that lead to the ports of São Francisco do Sul and Ilo (F2 and F4 respectively) are not attractive in the analyzed context.. Scenarios 2, 6 and 7 direct the decision to invest in the Araguaia-Tocantins Hidrovia (HAT) and in railroads linking the cities of Maringá and Cruz Alta to the Ports of Paranaguá and Rio Grande, F1 and F3, respectively.
Acesso aberto (Open Access)
Contribuição para o planejamento econômico de sistemas de energias elétrica: um algoritmo para a expansão simultânea da geração e transmissão usando aproximação linear
(Universidade Estadual de Campinas, 1983) BRANCO, Tadeu da Mata Medeiros; KOO, Robert Liang; http://lattes.cnpq.br/0610628446391103
Contribution tho the eletric power systems economic planning: an algorithm for the simultaneos expansion of generation and transmission using linear approximation. Economic Planning of Generation and Transmission in Electrical Power Systems constitutes a Nonlinear Optimization Problem which has some complexity and must be treated in a global manner. Several iteractive methods has been proposed to solve problems of this nature but sometimes are unaceptable due time and large computer storage requirements. This complexity is enlarged if generation and transmission were simultaneously optimized. Linear programming has been considered as a promissing tool to solve these problems but due the linearization of nonlinear functions the results presents some loss of accuracy, even so, for planning purposes these results are aceptable. In this work we propose a Global Algorithm for the Economic Planning of Simultaneous Expansion of Generation and Transmission in Electrical Power Systems based on the application of a Linear Programming Method and Minimum Cost Flow Algorithm which permits discret addition of generation and circuits units to the system with minimum investment cost in each period. Losses and maximum capacity of the lines are included in the algorithm, some examples are shown and at the end we suggest some extensions to further works.
Acesso aberto (Open Access)
Efeito dos diferentes tratamentos e embalagens nas características da polpa de acerola e na determinação dos teores de ácido ascórbico e das antocianinas durante o armazenamento
(Universidade Estadual de Campinas, 1999-12-21) SILVA, Maria de Fatima Vilhena da; MENEZES, Hilary Castle de; http://lattes.cnpq.br/6478475854489070
West Indian cherry is a rich source of ascorbic acid and a relative source of anthocyanins. The fruit and its products have been objects of great demand to serve individually as a nutritional source, or as a supplementary source of this vitamin for other foods. Ascorbic acid and the anthocyanins present antioxidant and preventative properties of various diseases which affect man, such as cancer, cardiovascular problems and others. One of the problems in the industrialization of this fruit and its products is related to the losses of ascorbic acid and the color of the product. Thus, this research was conducted with the objective of investigating the degradation of ascorbic acid and of the anthocyanins in West Indian cherry pulps submitted to different treatments: pulp without heat treatment, thermal inactivation or blanching, pasteurization (HTST) with and without aeration. The pulps were tested in glass and tin packages, and stored for six months for a better evaluation of their vitamin potential and lhe level of color maintenance of the products. All the experiments were developed at the pilot plant level. The second chapter considers the tests conducted with different methods for the determination of ascorbic acid in West Indian cherry pulp for the selection of those which offered good results as compared to CLAE, and which are fast, precise and economic. The method which fitted these characteristics, was that of titration with 2,6-dichloroindophenol. However, due to the intense color of the pulp, it was necessary to study a way to facilitate the titration and make the results more precise. The modifications made to this method to reach these objectives are presented in the second chapter. The new modifications showed result in excellent performance and the data were statistically similar to those obtained by CLAE. In the third chapter, an investigation of the physicochemical characteristics of the West Indian cherry pulps was made, emphasizing the effect of processing and types of package at zero time and during the storage period of six months. In this chapter, the individual results, the correlation amongst the analyses for ascorbic acid, total anthocyanins, pH, total titrable acidity expressed as malic acid and as citric acid, total solids and °Brix were shown. The results showed high correlation between ascorbic acid and anthocyanins. In the fourth chapter, a detailed study of the color of the pulps was made using the L a b system, that is, a study of the "hue", difference in color and saturation of color during storage. It was possible to verify from the results, that the product color was directly related to the type of processing and storage conditions. In the fifth and last chapter, the anthocyanins in the pulp without heat treatment were identified, and also the effects of processing on these pigments. The anthocyanin encountered in highest amounts was cyanidine, malvidine and pelargonidine also being present. The latter was shown to be more sensitive to heat treatments. Deaeration of the pasteurized pulp, and type of package showed no significant difference.
Acesso aberto (Open Access)
Estudo cristalográfico da deformação plástica em monocristais de cobre
(Universidade Estadual de Campinas, 1977-07-15) GOMES, José de Ribamar Seguins; MEDRANO, Ricardo Enrique
Previous results in Aluminum have show that the Critical Resolved Shear Stress is not the same for different slip system when flat single crystals are deformed. This is consequence either different stress is necessary to move edge screw dislocation or surface effect (aluminum have a oxide layer attached). In the present work similar analysis have been done in copper. Flat single crystals of special orientation have beem grown Under inert atmosphere in a graphite mould. The slip system is determined by following the tensile orientation with this purpose a deformation frame is attached to the X-Rays difractomer and movement of the tensile axis is measured by using the LAUE technique. It is found similar results than in aluminum which means that differences in flow stress are mainly tested to dislocations.
Acesso aberto (Open Access)
A Hidra e os pântanos: quilombos e mocambos no Brasil (sécs. XVII-XIX)
(Universidade Estadual de Campinas, 1997-03-19) GOMES, Flávio dos Santos; SLENES, Robert Wayne Andrew; http://lattes.cnpq.br/3081285853679184
In all Latin American societies where runaway slaves shaped maroon communities alternatives economy and fighting for feedom lived together with many allinace forms involving wholi colonial society. It had occured also in slave areas in Brazil where the quilombolas (maroons) organized themselves in social and economic groups and communities in order to maintain their autonomy, otherwise it may include daily relations with indians, farmers, rural workers, colonial authorities and, mainly slaves. Although these strategies -- wich involved conflict and contradictory aspects -- the runaways gave sense to their lives as subjects of their own history- In this thesis the historical experience of maroon societies in colonial amazoniam region and Maranhão will be analized. Futher the cases studied will be compared with other colonial areas, foccusing how slave communities was articulated wich the brazilian colonial society as a whole represents a threat.
Acesso aberto (Open Access)
Práticas de letramento no meio rural brasileiro: a influência do movimento sem terra em escola pública de assentamento de reforma agrária
(Universidade Estadual de Campinas, 2003-10-10) CAMPOS, Samuel Pereira; KLEIMAN, Angela Del Carmen Bustos Romero de; http://lattes.cnpq.br/4416353554838830
In this thesis we discuss the influence of Movimento Sem Terra (MST), understood as a discoursive communnity that acts institutional and intentionally at the brazilian rural workers formation, taking as reference its organization, social practices and ways of acting toward the social world. We focus our discussion at the literacy practices engendered in a public school, that reveals the influence of the Sem Terra literacy project in conflict with the school official project, broght into the researched school after its official establishment. As our research subjets were living diferent kinds of envolvement with the Sem Terra community, we assumed that researched school and the subjects involved in our field work, would present literacy practices related to the two projects in dispute in the school, characterized as emancipatory literacy project and schoolar literacy project, from the point of view of the new literacy studies. From this place, we analyse the educational project designed by MST, seen as an ideological, situated and emancipatoy literacy project (Street, 1984, 1995; Barton, 1998; Freire, 1978, 1987, 1995), and its influences over the literacy practices at the researched environment, focusing the two projects in conflict in the classroom of two Portuguese Language teachers, whose practices are representative of the two project in dispute at school.
Acesso aberto (Open Access)
Processos de multifonons no sulfato de níquel hexahidratado NiSO4.6H2O
(Universidade Estadual de Campinas, 1983-04-24) CANCELA, Luiz Sérgio Guimarães; GUALBERTO, Gilberto de Matos
Acesso aberto (Open Access)
Processos de relaxação em sistemas longe do equilíbrio termodinâmico
(Universidade Estadual de Campinas, 1985-08-16) MACHADO, Carlos José Freire; VASCONCELLOS, Aurea Rosas; http://lattes.cnpq.br/0475932786473160
Acesso aberto (Open Access)
Propagação de ondas eletromagnéticas em meios com camadas múltiplas usando funções de Green diádicas e sua aplicação no modelamento de florestas
(Universidade Estadual de Campinas, 1982) CAVALCANTE, Gervásio Protásio dos Santos; ROGERS, David Antony; GIAROLA, Attilio José; http://lattes.cnpq.br/7834721061998959
Acesso aberto (Open Access)
Síntese e atividade biológica de neolignanas 8.0.4' derivados e compostos correlatos
(Universidade Estadual de Campinas, 1991-07-03) SANTOS, Lourivaldo da Silva; BARATA, Lauro Euclides Soares; http://lattes.cnpq.br/1609747051706094
We have synthesized ca. 80 different aromatic compounds (8.0.4' -neolignans several derivatives and correlated compounds containing or 5 at C-8). These substances were submitted to bioassays namely PAF antagonists anti-leishmaniasis antibacteria, anti-schistossomose and anti-fungi. From the Virola surinmensin leaves we have isolated a 8.0.4' -neolignan, (+) -surinamensin whose absolute configuration was determinated as (+)-7S, 8S-surinamensin. Using crown ethers associated with metalic hydrides we have performed studies on the reduction stereoselectivity aiming a high diastereoselectivity of the β-ketoether reductions. We have also developed the first synthetic pathway Ieading to the enantiomerically pure 8.0.4' -neolignans using (+) - and (-) -Dimethyl tartrate as the chiral auxiliary groups which was sucessfulIy applied to the synthesis of (+) -virolin. Also we obtained chiral β -ketosulfides using the same route described earlier in an enantiosselectice pathway. Finnally, using safrol and eugenol abundant Brazilian raw material, we developed an alternative synthetic rout to the neolignans having bromohydrin as intermediate.
Acesso aberto (Open Access)
Síntese, caracterização e termoquímica de adutos entre metil, N, N'-dimetil e tetrametiluréia com haletos de zinco, cádmio e mercúrio-II
(Universidade Estadual de Campinas, 1980) ASSUNÇÃO, Francisco Pereira; AIROLDI, Claúdio; http://lattes.cnpq.br/1481366755849386
The reactions of zinc, cadmium and mercury halides with the ligands methylurea (MU), N, N'-dimethylurea (DMU) and tetramethylureia (TMU) yielded the following adducts: 2nL2x2, MLX2 (M + Cd, Hg) (X =Cl, Br and L=MU, DMU and TMU), M(TMU) 2I2 (M + Zn, Cd),Cd (DMU) 3Br3 and Hg (DMU) 2Cl2. These adducts were characterized by elemental analyses, melting points, conductance measurements, thermogravimetric. ifra red spectra and mass spectra. From the values os standard enthalpies of dissolution of thehalides,ligands and adducts in suitable calorimetric solvents, the standard enthapy of the reactions was calculated: MX2(s) + nL (l,s) = MLnX2 (s); ΔHθR. For the obtention of the standard enthalpies of formation ΔHθf of the adducts ΔHθR values were used. It was also necessary to determine the standard enthalpies of formation of DMU and MU, which were obtained by means of combustion calorimetry. The standard enthalpies, ΔHθD and ΔHθM, for the equations below were also calculated, howerer, it was necessary to determine the standard enthapy of vaporation of TMU and the standard enthalpies of sublimation of DMU and MU. MLnX2(s) + Mx2(s) + nL(g) ; ΔHθD. MLnX2(s) + Mx2(s) + nL(g) ; -ΔHθM. The thermal data in conjution with the mass spectra of the adducts suggest that possibility these compouds do not exist, at least in appreciable amounts in the gaseous phase. However, the enthalpy of the metal-oxigen bond was estimated, based on the fact that this mode of coordenation has occured with these three ligands, in agreement with the infra red results. The ΔHθR parameter establiches the order of basicity, TMU>DMU>MU, and the acidity order of of the metals, Zn>Cd>Hg.

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