Bonding of facial silicon with nanoparticles to an acrylic resin substrate

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

Efeito da aplicação do fluido de corte na usinagem da superliga Nimonic 80A

The nickel alloys have a chemical composition with high tenor of alloy elements which are responsible for the material's mechanical and thermal properties, but also are the main causative of problems during the machining, making the process difficult. The objective of this work is the study of the machining by external cylindrical turning of the nickel based alloy Nimonic 80A, seeking the machining optimization of this alloy, seeking the best condition of lubricant fluid use, providing real increases of productivity without the need of investments in new production means. Besides, the results of this work should offer more detailed information regarding the behavior of this alloy in relation to machining by turning. The machining experiences were accomplished in a specimen of the nickel alloy, considering the machining parameters: cutting speed (75 and 90 m/min), cutting depth (0,8 mm) and feed rate (0,15 and 0,18 mm/v). The valuations were accomplished in a CNC lathe and tools with of hard metal inserts. After each stage of the turning the measures of the cutting length were accomplished, of the waste of the tools through a magnifying glass (8x) and the roughness of the specimen evaluated in each phase of the process, with the aid of a portable roughness meter. Through light optical microscopy it was possible to observe the wear of the cutting tools for each appraised condition. The roughness values, Ra and Ry, for the appraised conditions were always superiors to the theoretical values. After analysis of the results it was possible to end that, the best acting for this work strip tested it was obtained for ap=0,8mm: f=0,15mm/rev and VC=75m/min, what resulted in a larger cutting length (1811 m)

Vitrocerâmicas porosas via conformação e consolidação com amidos

The search for new methods of manufacture of glass-ceramics with controlled porosity and permeability is interesting of the industrial and commercial point of view, and a challenge of great complexity. Porous glass-ceramics produced by sintering and crystallization of glasses can find applications, for example, as filters, materials with bactericidal properties, bio-implants, as catalytic and enzymes supports, among others. An alternative and low cost method of ceramic manufacture reaching different levels of porosity, for diverse purposes, is the conformation assisted by addition of starch, known as consolidation with starch. The objective of this project is to study the process of conformation with starch for making porous glass-ceramics from a commercial glass in the system Na2O-CaO-SiO2, whose kinetics of sintering by viscous flow and surface crystallization are known. The method of conformation with starches is innovative for glass-ceramics and its development opens the way for obtaining a new class of materials. We found a possible route for the production of porous compacts of glass particles, from the powder preparation to the removal of starch. It was observed that a glass powder obtained by dry milling in a ball mill with alumina balls for 24 h, afterwards mixed with water in an eccentric ball mill for 2 h, without the addition of a deflocculant, and subsequently mixed with starch also in an eccentric ball mill for 5 min resulted in slurries stable against sedimentation

Flexão e análise dinâmico-mecânica de compósitos 5HS e NCF com resina epóxi monocomponente produzidos por RTM

In order to study resin distribution and homogeneity of composite laminates manufactured by RTM, it was used CYCOM 890 monolithic toughened epoxy as a matrix with two different configurations of intermediated modulus (IM) carbon fibers: Satin Weave (5HS) and non crimp fabric (NCF). The injection parameters were defined based on Thermo Gravimetric Analysis (TG), Differential Scanning Calorimetry (DSC) and rheological analysis. After processing the material, the resin/fiber impregnation was studied using ultrasonic test, Thermo Gravimetric Analysis, Differential Scanning Calorimetry, Dynamic Mechanical Analysis (DMA) and flexural tests. Therefore, it was able to observe an internal residual stress during the cooling process in both laminates, higher in the composite using NCF fabric due to the lack of symmetry, although a good proportion of fiber/matrix has been verified by the lower values of flexural modulus deviation. The DMA enabled the visualization of glass transition and its association with the inter and intra molecular interaction and movement, in which the NCF composite presented better permeability due to the lowest temperature of glass transition, when compared to the Satin Weave composite

Neuroimagem de encéfalo de gatos domésticos: correlação entre tomografia computadorizada e cortes anatômicos

Pós-graduação em Cirurgia Veterinária - FCAV

Obtenção de rochas sintéticas a partir de resíduos de vidro comercial e pó de granito

Pós-graduação em Engenharia Mecânica - FEG

Resistência à tração de coroas de NiCr cimentadas sobre munhões de liga de titânio, com 4 diferentes tipos de cimentos

In this work of tensile strength was evaluated the efficacy of 4 cements (S. S. White zinc phoshate, Ketac Cem Easymix glass ionomer, RelyX Luting 2 composite resin/glass ionomer and Panavia 21 TC special acrylic resin) used to fix NiCr crowns to usinated titanium alloy abutments. Were used 40 abutments distributed in groups of 10 elements, to each material. The mechanical essays were developed at a MTS 810 universal machine, adjusted to a 0.5 mm/m velocity. The ANOVA applied to data pointed out the existence of significant differences between groups; the subsequent Tukey´s test (p<0.05) also detected significant differences, except at comparisons of phosphate versus RelyX and phosphate versus Ketac Cem. The better performance was presented by Panavia 21 (1,127.996 N); RelyX (478.197 N) showed itself similar only to phosphate (430.662 N), wich had a performance similar to that of Ketac Cem (227.705 N).

Cerâmicas porosas a base de zircônia na forma de filmes suportados preparados a partir de emulsões

Pós-graduação em Química - IQ

Capacidade de termoplastificação da guta-percha com diferentes conicidades

jObjective: The objective of this study was to evaluate the thermoplasticity of the gutta-percha cones used for root canal obturation: Dentsply convencional (Dentsply Ind. e Com., Petrópolis, RJ, Brazil), Dentsply 0.04, (Dentsply Ind. e Com., Petrópolis, RJ, Brazil), Antaeos 0.04 (VDW GmbH, Munich, Germany), ProTaper (Dentsply Ind. e Com., Petrópolis, RJ, Brazil) and Alfa 0.06 (VDW GmbH, Munich, Germany). Material and method: Specimens of each material (n = 10) were prepared after heating. After 24 hours were again heated to 70 °C and placed between two glass plates and subjected to a compression of 5 kg for 2 minutes. The scanned image of the groups before and after the compression was analyzed with the software Image Tool (UTHSCSA Image Tool for Windows version 3.0, San Antonio, TX, USA). The flow capacity of the different materials was determined by the difference between the initial and final area of each specimen. The results were submitted to ANOVA and Tukey test with significance level of 5%. Result: Among the material evaluated, the gutta-percha cones Alpha 0.06 and ProTaper presented more thermoplasticity than other groups (p < 0.05). The Dentsply gutta-percha presented thermoplasticity intermediate. The groups Dentsply 0.04 and 0.04 showed lower thermoplasticity after heating (p > 0.05). Conclusion: The gutta-percha present different property of thermoplasticity, which is important to selection of thermoplastic obturation techniques.

Liberação controlada de nutrientes e novos sistemas para avaliação de espécies químicas empregadas na fertilização

Pós-graduação em Química - IQ

Retratos da Espanha em Os fantasmas de Goya

1792, Madri. After years of inactivity, the Spanish Inquisition is born again with the mission of containing the laic winds that blow from the revolutionary France. Inês Bilbatúa, a rich merchant’s daugther, is victim of the inquisitorial machinery which tortures and violates her, through one of their abetters, the Dominican monk Lorenzo. Before being arrested, the young lady had served as model for the painter Francisco of Goya, who had also portrayed the monk Lorenzo. The Aragonese painter’s figure serves as narrative conductor of a history that narrates the young Inês’ via crucis and, at the same time, it recreates the historical scenery of the Napoleonic invasion (1808), through a basic element, the painting. Our work intends to analyze the relationships among movie, painting and history present in “Goya’s ghosts” (2006), of the Czech director Milos Forman (1932) - whose script was adapted to a homonymous book in 2007 -, a movie that is based on the artistic production of Francisco of Goya y Lucientes (1746 -1828), official painter of Carlos’ IV (1788 -1808) court and the most lucid columnist of his time, that knew how to capture in his works the religious fanaticism, the populist fervour, the governor’s hypocrisy and the horror and the violence of the war.

Characteristics of PbO-BiO1.5-GaO1.5 glasses melted in SnO2 crucibles

PbO-BiO 1.5-GaO 1.5-based glasses are good candidates for optical applications, because of some of their interesting characteristics, such as high refraction indices and high transmission in the ultraviolet (UV), visible (VIS), and infrared (IR) regions. A limited stage in the processing of these glasses is the corrosion that is caused by the melt in all currently used conventional crucibles, such as noble metals (platinum or gold) and Al 2O 3. The absorption of crucible material by the glass composition may reduce the transmission level, the cutoff in the UV-VIS, and IR regions, and the thermal stability. In this study, a SnO 2 crucible has been tested for PbO-BiO 1.5-GaO 1.5 molten glass. Optical and thermal analyses show, in some cases, advantages over the use of platinum and Al 2O 3 crucibles. A visible cutoff value of 474 nm has been measured, and a longer melting time (850°C for 4 h) results in a significant reduction of the O-H absorption band at 3.2 μm.

Penetration of 35% hydrogen peroxide into the pulp chamber in bovine teeth after LED or Nd:YAG laser activation

This aim of the present study was to evaluate the pulp chamber penetration of 35% hydrogen peroxide activated by LED (light-emitting diode) or Nd:YAG laser in bovine teeth, after an in-office bleaching technique. Forty-eight bovine lateral incisors were divided into four groups, acetate buffer was placed into the pulp chamber and bleaching agent was applied as follows: for group A (n = 12), activation was performed by LED; for group B (n = 12), activation was performed by Nd:YAG laser (60 mJ, 20 Hz); group C (n = 12) received no light or laser activation; and the control group (n = 12) received no bleaching gel application or light or laser activation. The acetate buffer solution was transferred to a glass tube and Leuco Crystal Violet and horseradish peroxidase were added, producing a blue solution. The optical density of this solution was determined spectrophotometrically and converted into microgram equivalents of hydrogen peroxide. The results were analysed using ANOVA and Tukey's test (5%). It was verified that the effect of activation was significant, as groups activated by LED or laser presented greater hydrogen peroxide penetration into the pulp chamber (0.499 +/- 0.622 microg) compared with groups that were not (0.198 +/- 0.218 microg). There was no statistically significant difference in the penetration of hydrogen peroxide into the pulp chamber between the two types of activation (LED or laser). The results suggest that activation by laser or LED caused an increase in hydrogen peroxide penetration into the pulp chamber.

Microbiota fúngica de passeriformes de cativeiros da Região Noroeste do Estado de São Paulo

Birds are hosts for a rich fungal microbiota which can act as potent pathogens for humans and other species of animals, causing thereby serious public health problems. The objective of this study was to evaluate the participation of birds kept in containers in the epidemiology of infectious diseases such as cryptococcosis and aspergillosis, thus verifying the maintenance and spread of pathogens in the environment. 36 samples of excretas of passeriformes were collected and were cultivated in Sabouraud Dextrose Agar 4% at room temperature and 37°C. The isolated fungal colonies were classified according to their morphological and staining characteristics. Subsequently, those in yeast form were peaked in Niger Agar, incubated at 30°C. In one sample showed growth of more than one type of colony and there was verified the presence of 25.0% of Penicillium spp., 19.4% of Trichosporon spp., 13.9% of C. gattii, 11.1% of C. neoformans, 11.1% of Candida spp., 8.3% of Rhizomucor spp., 8.3% of Aspergillus spp., 2.8% of Nigrospora spp. and 2,8% of Geotrichum spp. It can be conluded by the expost that birds shed continuously pathogenic microorganisms in their feces acting in definitive form in the infectious diseases ecoepidemiology.

Estudo comparativo do Biogran® e Endobon® associados a implantes com defeitos periimplantares

Pós-graduação em Odontologia - FOA