Caracterização geológica e estrutural da porção centro-norte do greenstone belt de Faina, Faina-GO

The area where the study was conducted is located in the central-western state of Goias. It geologically inserts the northern portion of the Greenstone Belt of Faina which belongs to the Archean terranes that fits in Brasília Fold Belt and Tocantins Structural Province. This region is known for its greenstone lode gold potential and it was heavily exploited by pioneers and prospectors, leaving many records for where they have been through. Preliminary work done by Orinoco Brasil Mineração in their required areas at the region showed that the environment is promising for gold mineralization and that the ore is controlled by structures. Therefore the objectives of this work were the geological and structural mapping in semi detail scale to improve geological, stratigraphic and structural controls present attributing possible ore understanding. With the development of the work there were recognized on the desktop three structural domains separated by a thrust fault. For each domain were discriminated the geological units ranging in gneisses, quartzites formed from coarse sediments arcoseanos, and schists. By mapping structures there were found five deformation phases, Dn-2, Dn-1, the Dn event that generated the main foliation (Sn) in high representation and two post-stages Dn with brittle late manifestations. The detail mapping of the Rattlesnake Gallery showed that the mineralized quartz vein is consistent with axial-plane foliation Sn-2 belonging to the oldest deformation Dn-2 phase and that the high grade is distributed in the hinge region folds of the same phase

Caracterização petrográfica das zonas de alteração hidrotermal associadas aos pegmatitos da mina Bom Futuro, Rondônia

The Bom Futuro tin deposit is located in Ariquemes, north-central state of Rondônia. Since its discovery in the late 80s, the tin deposit of Bom Futuro has been explored and considered one of the leading Brazilian producers of cassiterite, exploring it mainly in secondary deposits (placers) in the vicinity of the hill Bom Futuro. The primary mineralization occurs in the contacts between quartz veins and pegmatites with the rocks of the hill and its exploitation has been the goal of new studies in the area. These bodies occur in all rock types of the hill, leading edges of hydrothermal alteration with each rock. The focus of the study is the characterization of hydrothermal alteration through the analysis of the edges of pegmatitic veins intruded on each of the main rock types found on the hill Bom Futuro, which are: biotite gneiss, biotite amphibolite, subvolcanic breccia, topaz leucogranite, topaz leucoriolito and micro melassienito porphyry. The analysis and comparison showed familiarities between the edges of alteration encountered, and possible subdivision into three main zones: the inner zone or the vein itself, intermediate zone or transition zone and the change zone where the passage of hydrothermal features to rocks features is gradual. The cassiterite and sphalerite were found scattered in three zones, however in larger quantities in the intermediate zone, near the contact

Influência do uso de hipoclorito de sódio 2,5% e extrato glicólico de sálvia 20% durante o preparo biomecânico sobre a resistência adesiva de retentores intra- radiculares: avaliação através do teste de push-out

The aim of this study it was to evaluate the use of irrigating solution used during root canal preparation on the adhesive cementation of prefabricated fiberglass pins. The bond strength between different regions of the root and the fiberglass pins cemented into the root canal were evaluated by push-out assay. For this study, 36 human teeth were used, all equally prepared. The irrigating solutions used for biomechanical preparation were: saline solution, sodium hypochlorite 2,5% and glycolic extract of salvia 20%. The dual cure resin cement was used for cementation of pins. After cementation, specimens were sectioned to give 3 slices of approximately 2 mm each (cervical, middle and apical), which were submitted to mechanical push-out test. Were performed ANOVA and Tukey's test with a significance level of 5%, for the analysis of mechanical test. Comparing the thirds we observed that the only solution that presented statistical difference in the bond strength was sodium hypochlorite, which showed higher values for the middle and apical third compared with the cervical third, but when compared without taking into consideration the dental thirds, solutions studied showed no differences in bond strength. Therefore, it was concluded that the solutions studied can be used during endodontic treatment without causing harmful effects on the final adhesive restoration

Análise comparativa entre sistemas de resfriamento de injeção de plástico

This study aims to prove the economic feasibility of the installation of mechanical compression chillers on plastic injection molding machines in order to reduce the production cycle time of toothbrush cables in a specific case study. This evidence was confirmed by the comparative analysis of the system replaced and the new system installed. The old system had only one closed loop cooling tower which pumped chilled water to the injection molds, and the new system has the same tower sending cold water to the condensers of individual chillers installed on each injection machine. We conducted an analysis of energy efficiency in each system, showing that in terms of thermal efficiency virtually nothing has changed, but in terms of electricity demand the new system consumes 60.3 kW more. We conducted an analysis of machine productivity for both systems, showing a much higher productivity of the new system due to reduced cycle times caused by the presence of chillers and their greater cooling capacities. Equipped with data such as electricity rates, increases in operating costs and initial investments, the increase in consumption and demand of electricity plus the cycle time reduction were also calculated over so the simple payback 1 year and 2 months was reached

Estudo da inflexão da Serra do Garrote e sua influência na zona de falha de Vazante (MG)

The Vazante Fault Zone (VFZ), located northwestward of Minas Gerais, host the largest zinc deposit known in the Brazilian territory. This structure is hosted in Vazante’s Group rocks, a metassedimentary sequence of marine environment. Near Vazante is situated the south end of the VFZ. To the west, occur the Serra do Garrote inflexion, characterized by a curvature in the contact of Formations Serra do Garrote and Serra do Poço Verde. This structure is through the analysis of aerial imagery of the region and represented in the published geological maps. The objective of this work is to understand what causes this inflexion and determine whether it affects the VZF, causing a shift in the same, and possibly, in the mineralization as well. To this end, it was done a mapping work in the region covering the Serra do Garrote inflexion and the south end of the VFZ, in 1:25.000 scale, supplemented by petrographic description of thin section and geologic sections, with cooperated to the understanding of the structural evolution of the region. Data analysis allowed the identification of six deformation phases. The D1 an D2 phases generated the main foliation. The D3 phase generate kink bands folds, with NS axis and vertical axial plane. The fourth phase is responsible for generating the Vazante Fault Zone. The fifth phase produces low angle folds and shear zones, subparallel to S1//S2. The last phase generates folds with NW axis and vertical axial plane, with causes the inflection of lithologic contactas. Field observations also make possible the conclusion that the Vazante Fault Zone presents a south continuation, which is affected by deformation associated to D6 phase attributing to the trace of the VFZ a curved geometry, similar to that exhibited by lithologic contacts between units of the map

Densitometria óssea de cães SRD utilizando radiação gama

A proposta desse trabalho surgiu da possibilidade de unir metodologias eficientes para estabelecer valores mais precisos de densitometria óssea. A densidade óssea é um parâmetro biofísico de grande importância experimental e clínica, que permite avaliar o processo de mineralização óssea. O objetivo deste trabalho foi determinar a densidade óssea e o coeficiente de atenuação de massa da radiação gama com o radioisótopo 241Am com fotopico de 59,6 keV em rádios de cães SRD (Sem Raça Definida). Conclui-se a que a densidade média das amostras foi de 1,91 g/cm³ com um desvio padrão de 0,0599. Para o coeficiente de atenuação de massa, o valor médio foi de 0,241 cm2/g, com desvio padrão de 0,0151. Para ambos os parâmetros o coeficiente de variação foi pequeno implicando em uma baixa dispersão. Isso também demonstra que os métodos aplicados foram eficientes e de fácil aplicabilidade

Desenvolvimento de metodologias analíticas para determinação de selênio, cobre e manganês por GFAAS em amostras de vegetais de cultura orgânica e convencional utilizando extração por ultra-som

No presente trabalho é proposto um método para determinação de cobre, manganês e selênio em amostras de vegetais de cultura orgânica e convencional utilizando ultra-som no processo de extração dos analitos e posterior quantificação por espectrometria de absorção atômica em forno de grafite (GFAAS). Utilizando como solução extratora HCl 0,10 mol L-1, as condições ótimas de extração estabelecidas foram: massa de amostra de 100 mg; granulometria da amostra < 60 m; tempo de sonificação de cinco ciclos de 40 s e potência de sonificação de 136 W. As determinações dos analitos por GFAAS foram feitas utilizando-se temperaturas de secagem de 90-250 oC, temperatura de pirólise de 1300 oC, temperatura de atomização de 2300 oC e temperatura de limpeza de 2800 oC. Foi utilizado como modificador químico nitrato de paládio co-injetado junto com as amostras e tungstênio como modificador permanente. A exatidão e precisão do método de extração proposto foram avaliadas utilizando-se padrão certificado Corn Bran, RM 8433 – National Institute of Standards and Technology. Os resultados obtidos pelo método de extração por ultra-som mostraram-se equivalentes aos obtidos pelo método utilizando-se mineralização ácida das amostras em forno de microondas. No entanto, a metodologia proposta diminui consideravelmente o tempo de análise, o que favorece a velocidade analítica. Além disso, a quantidade de resíduos gerados para o ambiente também é bastante minimizada

Geologia do depósito de ouro do alvo guarda-mor, na sequência Jaupaci (Israelândia - GO)

The study area of the Guarda-Mor target (Israelândia-GO) contextualizes the terrains of the estaern portion of the Arenópolis Magmatic Arc, more accurately, the Neoproterozoic associations inserted in the field of the Jaupaci volcano-sedimentary sequence. The mapped area is located in the central-western of Goiás state. The presente paper has as main objective to characterize the structural, petrographic and litogeochemistry of the target rocks beyond to compare these factors with the Mina Bacilândia rocks (Fazenda Nova-GO) in order to assess the genetic similarity of volcano-sedimentary units and deposits associated. The Guarda-Mor target is represented by the Jaupaci metavolcanic rocks sequence presenting bimodal volcanism. This sequence consists in metafelsic rocks like sericite/muscovite quartz schist, phyllite and metarriolites and/or metariodacites with calc-alkaline geochemical signature and metamafic rocks with tholeiitic character formed by actinolite - chlorite schist and chlorite - quartz schist. Besides the package of supracrustal rocks also can be observed the occurrence of a local intrusion syn- to late - tectonic named Granito Subvulcânico. In the study area beyond the marked volcanism also seen an event of crustal melting granitogênese evidenced by the presence of 2 granites at the east and the west of the map, Granito Israelândia and Granito Iporá respectively. Structural analysis both at the macro and micro have identified 3 deformation phases. The types of rock on the region record features in the metamorphic facies top and down. These features were subdivided into 3 metamorphic areas: the east and West areas show thermal metamorphism due to intrusion of adjacente granites while the central domain displays features of regional metamorphism. Gold mineralization of the Guarda –Mor deposit target suggests a possible structural control beyond pronounced the hydrothermal alteration. The mineralization may also be...

Estudos de degradação de filmes de polietileno

A produção de lixo pela humanidade é inevitável, porém, o destino dos residuos sólidos e seu acondicionamento inadequado têm trazido graves problemas ambientais. Dentre os resíduos sólidos, os plásticos merecem destaque, pois cresceram significativamente em uso e descarte, totalizando 20% do volume mundial de lixo. Isto decorre de algumas das propriedades destes materiais, como durabilidade, resistência, leveza e baixo custo de produção. Nas grandes cidades brasileiras, 7% do lixo produzido correspondem a produtos de plástico em filme, geralmente usado em aplicações de curta duração, como o polietileno. Este material persiste no ambiente por décadas, sendo, portanto, resistente à degradação. Diversos destinos podem ser tomados pelo resíduo de polietileno descartado, como a deposição em lixões e aterros sanitários, incineração, reciclagem e biodegradação. A biodegradação pode ser definida como a degradação catalisada por atividade biológica, levando, no final do processo, à mineralização e/ou formação de biomassa. Na natureza, a destruição destes materiais se dá, na verdade, por meio da “degradação ambiental”, na qual atuam sinergeticamente a biodegradação, a fotooxidação, a termo-oxidação e a hidrólise. Neste sentido, desde os anos 1970, diferentes formulações foram propostas para otimizar a susceptibilidade do PE à degradação ambiental. Sabe-se que o PE está sujeito a sofrer mudanças quando exposto à luz ultravioleta e/ou ao calor, e que estas modificações podem alterar a resposta dos microrganismos no processo de biodegradação. Desta forma, este estudo analisou as modificações ocasionadas por tratamentos com luz ultravioleta, calor e exposição ao sol, bem como a resposta da microbiota natural do solo a estes tratamentos, através de análises de espectroscopia... (Resumo completo, clicar acesso eletrônico abaixo)

Caracterização mineralógica, petrológica e química da sulfetação nos reef's da mina Canavieiras, Jacobina, Bahia

In the Serra de Jacobina, localized in the North Central portion of the state of Bahia, occours the Jacobina Group. It’s a sedimentary basin and the gold deposit is stocked on the basal portion, which consist on quartzites intercalated with oligomítico metaconglomerates of Serra do Córrego Formation. There are controversies about the origin of the gold mineralization, but the currently most accepted hypothesis corresponds to a paleoplacer deposit with subsequent ore remobilization and concentration by hydrothermal process. The sulphidation is one of the main results of hydrothermal process, which was more detail characterized, besides identifying if there was more than one sulfides phase generation and its relationship with gold mineralization. The analyzes were performed from the main reef's (metaconglomerates mineralized levels) of Mine Canavieiras: Maneira, Holandez, Liberino, Piritoso, MU and LU. Chemical analyzes semi-quantitative were developed with EDS in MEV and also petrographics analyses. The main sulfide is pyrite, followed by chalcopyrite. Six groups of pyrite were classified according with chemical composition, however they show similarities in their habit and occurrence. Were identified four types of chlorite, labeled A, B, C, D. Gold occurs in free form, associate to pyrites, to Fe-Ti-Muscovite, to chlorite type B and to microfractures with iron hydroxide. Gold presents three different compositions: pure, with Ag or associated with U-Zr. The results of chemical analysis showed that the hydrothermal process have as their main source, ultramafic rocks present in the Jacobina Basin

Estudo in vitro da anatomia das projeções de esmalte cervical em dentes molares

The cervical enamel projection (CEP) is an anatomic variation that can be found in the cement enamel junction, it´s recognition and early diagnosis improves outcome the tooth involved, allowing greater efficiency in treatment. The knowledge of the location, grade and incidence of CEP is decisive on prevention and treatment of periodontal disease. It were studied 1200 molars (600 mandibular molars and 600 maxillary molars) separated from the collection of teeth on the Discipline of Anatomy in FOSJCampos - UNESP. Each group of 600 teeth was separated from the second side (300 teeth) and the second type (first, second or third molar). Each tooth had thoroughly inspected the cervical region, in all their faces, in order to verify the incidence and the grade of CEP in each surface. It was found that the CEP covered in 278 (23,17%) teeth was 146 (52,52%) mandibular molars and 132 (47,48%) maxillary molars. The CEPs were concentrated on a tooth surface in 222 (79,86%) teeth, in two surfaces 53 (19,06%) teeth, and in three surfaces in three (1,08%) teeth. From the total of 4.800 surfaces examined the CEPs were found in 337 surfaces, and 228 (67,66%) surfaces of the grade I, 60 (17,8%) grade II and 49 (14,54%) grade III. The buccal surface presented 207 (61,42%) CEP, the lingual surface in 57 (16,91%), the mesial surface in 35 (10,39%) and the distal surface in 38 (11,28%) CEP. The results of this study demonstrated that the CEPs have focused more on the mandibular teeth on only one surface of the tooth, the grade I was the most found and the buccal surface the most involved

Estudo da anatomia interna dos incisivos laterais superiores pelos métodos radiográficos digital e convencional

The maxillary lateral incisor has a very peculiar and internal morphology that can be influenced by the its external anatomy such as supernumerary roots and ruts deep root, which often hinders an effective endodontic treatment. Generally, this tooth have a single root with one root canal, but teeth with two to four channels can be found. The main canal can present ramifications such as accessory canals, laterals, collaterals, recorrents and apical deltas. All this factors interfere directally on endodonthics treatment. The objective of this work is a study of the internal anatomy of the maxillary lateral incisors by digital and conventional radiographics methods, comparing the results obteined by each method Six hundred upper lateral incisor were used in this study teeth of the collection of the Department of Anatomy ICT – UNESP. All the teeth were radiographed by vestibular face, using a digital radiographic unit(Dabi Atlante). After this step, all the teeth underwent by conventional radiographic technique(Kodak 2200) so that the results obtained were compared. To classify the channel system, it was adopted the classification of Pucci and Reig. All data obtained by digital technique were compared with those obtained in the conventional technique and were subjected to statistical analysis

Abordagem metalômica quantitativa de mercúrio em peixes da região amazônica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito de diferentes antibióticos no processo de reparo em reimplante de dentes mantidos em leite: estudo em ratos

Pós-graduação em Odontologia - FOA

Efeito de dentifrícios fluoretados e suplementados com nanopartículas de trimetafosfato de sódio sobre a desmineralização, remineralização e erosão dentária

Pós-graduação em Ciência Odontólogica - FOA