956 resultados para Densidade eletrônica
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Recent bonding systems have been advocated as multi-purpose bonding agents. The aim of this study was to determine if some of these bonding systems could be associated to composite resins from different manufacturers. This investigation was conducted to test lhe shear bond strength of three bonding systems: Scotchbond Multi-Purpose (3M Dental Products), Optibond Light Cure (Kerr) and Optibond Dual Cure (Kerr), when each of them was associated to lhe composite resins: Z1 00 (3M Dental Products), Prisma - APH (Dentsply) and Herculite XRV (Kerr). Seventy-two flat dentin bonding sites were prepared to 600 grit on human premolars mounted using acrilic resins. The teeth were assigned at random to 9 groups of 8 samples each. A split die with a 3mm diameter was placed over lhe surface of lhe dentin treated with one of lhe adhesive systems, and lhe selected composite resin was inserted and light cured. The split mold was removed and all samples were termocycled and stored in 37ºC water for 24 hours before testing. Shear bond strength was determined using an lnstron Universal testing machine. Some failures were examined under lhe S.E.M. Data was analysed by one-way analysis of variance, that demonstrated a significant difference (p<0,05) in the mean shear bond strength among Optibond Light Cure (15,446 MPa), Scotchbond Multi-Purpose (13,339 MPa) and Optibond Dual Cure (10,019 MPa). These values did not depend on the composite resin used. The association between bonding system/composite resin was statistycally significant (p<0,05) and the best results were obtained when the composite resins Z100 and Herculite were used with the adhesive system Optibond Light Cure, and when the composite resin APH was used with the adhesive system Scotchbond Multi-Purpose
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The purpose of this study was to evaluate the apical sealing ability and the marginal adaptation of five dental materials used in retrofillings or applied to the bevelled root surface. One hundred and forty extracted single rooted human teeth were used, divided into seven groups of twenty each. ln the first, second, third and fourth groups, the teeth were apicoectomized, submitted to cavity preparations and retrofilled with one of the following materiais: zinc free silver amalgam, a dentin bonding system plus composite resin, a glass ionomer cement ora compomer. In the fifth, sixth and seventh groups, the teeth were apicoectomized and capped on the bevelled root surface with one of the following materiais: a dentin bonding system plus composite resin, a glass ionomer cement or a compomer. Two specimens of each experimental group were evaluated for the marginal adaptation using scanning electron microscopy. The remaining 126 specimens were immersed in 2% methylene blue dye, stored for one week at 37ºC and the infiltration was evaluated with a stereomicroscope. The results showed that the glass ionomer cement presented the lowest values of marginal infiltration when used as retrofilling material, with a significant statistical difference when compared with the others tested materials. When used as apical capping, the glass ionomer cement and the compomer were equivalent and significantly better than the dentin bonding system plus composite resin. Using scanning electron microscopy, all the materials showed some slight adjustment problem. ln the retrofilling, the smallest marginal gaps were observed with the compomer and the dentin bonding system plus composite resin, while the largest were observed with the glass ionomer cement and zinc free silver amalgam. ln the apical capping, the smallest marginal gaps were observed with the compomer and the dentin bonding system plus composite resin and ...
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Aquicultura - FCAV
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Pós-graduação em Ciências da Motricidade - IBRC
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Cauliflower is one of the most planted vegetable throughout Brazil, being a very profitable crop. The use of denser plantings can increase crop yield and improve financial returns to producers. This study aimed to verify the combination effect of different spacing between plants in row and between rows on the cauliflower 'Piracicaba Precoce’ inflorescences productivity and quality. In the experiment, a randomized block design was used and treatments consisted in three distances between rows (70, 80 and 90 cm) with three distances between plants in row (50, 60 and 70 cm) and four replications. Total productivity and productivity by inflorescences size classes were assessed as well as the quality by checking the inflorescences’ mass. The row density did not change the produced heads quality, although the density between plants reduced the inflorescences size. The spacing 70 x 50 cm, totalizing 28,571 plants per ha, due the higher productivity, greater than 14.0 t ha-1 , and still not compromise the inflorescence size can be recommended to the cauliflower "Piracicaba Precoce” production in the region.
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Objectives: Epidemiological studies have shown a relationship between long-term use of proton pump inhibitors and bone metabolism. However, this relationship has not yet become established. The aim of the present study was to analyze the mechanical properties and bone mineral density (BMD) of rats that were subjected to long-term omeprazole use. Methods: Fifty wistar rats weighing between 200 and 240 g were divided equally into five groups: OMP300 (omeprazole intake at a dose of 300 moL/kg/day); OMP200 (200 moL/ kg/day); OMP40 (40 moL/kg/day); OMP10 (10 moL/kg/day); and Cont (control group; intake of dilution vehicle). The solutions were administered for 90 consecutive days. After the rats had been sacrificed, their BMD, the mechanical properties of the dissected femurs and their serum Ca++ levels were analyzed. Results: The BMD of the OMP300 group was lower than that of the controls (p = 0.006). There was no difference in comparing the OMP200, OMP40 and OMP10 groups with the controls. The maximum strength and rigidity of the femur did not differ in the experimental groups in comparison with the controls. The OMP300 group had a statistically lower serum Ca++ concentration than that of the controls (p = 0.049), but the other groups did not show any difference in relation to the controls. Conclusion: Daily intake of 300moL/kg/day of omeprazole decreased the BMD of the femur, but without changes to the rigidity and strength of the femur in adult rats. © 2
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This dissertation shows a new tool in the process of producing specialized printed media: desktop publishing. Because it is an important tool to this communication media, the visualization of its evolutionary journey began in the pre-history of informative vehicle, advancing to the informatics society. And it was just in this last social stage that desktop publishing legitimized its function, resulting in impacts on the production of these media and conditioned new styles. At the presentation of this new post-industrial society, a change of work and leisure sphere was verified, whose fusion is present and in this interaction, desktop publishing arose at home, in the little bureaus. In this journey, desktop publishing became an object of reflection because of its conditioning aspects that fostered moments of observation in relation to a possible threat to creativity, thanks to its facilities and clichés. On the other hand, different positive aspects of desktop we also shown, at the same time, its conditioning aspects resulting into a restudy of its execution in different printed media, showing its effects and sharing points of view. So, new styles and a editorial way of production were seen too. Add to this aspect desktop publishing – in general meaning – the computerization of magazine articles – has been producing resignation of journalists, which is another important aspect in the presenting dissertation.
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This paper presents some results of MFI and OIT tests performed on HDPE geomembranes of 0,8 and 2,5 mm that were exposed to weathering effects and leachate after 30 months (2,5 years). The aim of this work is the evaluation of the oxidative degradation process by comparison of fresh and exposed samples results. The expositing and tests were performed according the following standards recommendations: ASTM D1435 (weathering), ASTM D5747 e D5322 (leachate), ASTM D1238 (MFI) e D3895 (OIT). The results shows, for instance, that the MFI values presented high increases on the HDPE (2.5 mm) showing that polymeric chain break occurred for both exposures and, therefore, oxidative degradation. Concerning the OIT values all the geomembranes presented very low values even in the fresh samples. This demonstrates that there wasn’t an antioxidant package appropriate for these membranes.