931 resultados para 091207 Metals and Alloy Materials
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This work consists of preparation and characterization of glasses containing transition noble metals and the study of optical properties of such materials. The glasses were prepared by quenching of the glass melt followed by heat treatment and polishing of the monoliths. The structural characterization of glasses was made using differential thermal analysis, X-ray, Raman and infrared spectroscopies, while the optical properties were studied by UV-Vis and M-Lines spectroscopies. Preliminary results have shown that the color of the glasses is dependent on both concentration of silver and the melting temperature of the melt. Controlled heat treatments have been used to induce the crystallization of Ag nanoparticles within the glass. The study of crystallization was accompanied by electron microscopy and UV-Vis spectroscopy. Data from electron diffraction, as well as chemical analysis, EDX, were obtained using a transmission electron microscope. EDX data have shown that the atomic percentage of Ag is higher on the nanoparticle. X-ray diffraction was used in order to characterize the composition of the crystals and cubic AgCl was identified as the main crystallized nanophase obtained after annealing
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This work consists of the implementation of the steps Define, Measure , Analyze , Improve and Control ( DMAIC ) to develop a Six Sigma project in an industry the food industry. The objective was to demonstrate a potential for reducing the occurrence of crushed cans in potting milk powder industry in a White Belt project. The food industry accounts for about 9 % of Brazil's gross domestic product ( GDP ), generating thousands of jobs . Among the major sectors of the food industry is the manufacturing sector of milk , occupies approximately 10 % of the total turnover of the food industry . Brazil is considered today one of the eight largest producers of milk powder in the world. The milk powder is packed , mostly for aluminum cans that are lined internally with varnishes and other materials to protect the milk of metals from aluminum. When the cans are dented food protection is compromised and may lead ingestion causing dis-eases such as botulism. Aiming to solve the problem of dented cans methodology was used as a case study with a quantitative approach through the DMAIC method. Some quality tools used in each step of the project as brainstorming , cause and effect diagram , flowchart , ef-fort and impact matrix, 5W1H , among other Pareto diagram is presented . A survey about the disposal of cans in the company verifying a mean loss and, from this histor-ical , a goal loss was calculated was performed . With the target set we calculated the annual saving design . During application of DMAIC was found that the highest rate of loss occurred in transportation between the factory and the factory that fills cans milk . Several actions were taken to resolve problems that resulted in dented cans and the first two months of phase control it was found that the smaller losses calculated target resulting in a saving for the company. The short time of implementa-tion of the Improve phase did not allow a more detailed a ...
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The present study aimed to analyze how develops the reverse logistics process applied in electrical and electronic products. Such analysis was obtained through literature search and with the completion of a case study, which was developed at the company's Oxil Reverse Manufacture, showing the advantages obtained as well as the difficulties faced in the implementation of the reverse logistics process. The development of this research shows its importance in so far as the residues generated by electronic components, which are one of the most harmful to the environment and harmful to human health, highly possessing heavy metals and non-biodegradable materials in their composition. In this way, the components collected from this activity, should be properly recycled, reused and finally housed in suitable location, these steps that are part of the reverse logistics process
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The urban residues put in landfill of the city of Sa˜o Carlos-SP, Brazil, in 2004 represent 58.7 % of decomposed organic material. The aim of this research was to characterize samples of urban solid waste and its organic extracts targeting the use of this residue without damaging the environment. The curves were obtained in a nitrogen atmosphere, a heating rate of 20 C min-1 , the temperature of 30–600 C. In the original sample after humidity loss, an event occured concerning the water constitution in the TG curve with an endothermic peak in the DTA curve. There was a presence of inorganic residue in the ashes. The organic matter present in the USR sample disposed in the landfill is constituted by several polarity, organics compounds from the degradation of lignin, cellulose, lipids, and other materials which thermal stabilities are distinct. The hexane extract features in its constitution two fatty acids, stearic and triacontano´ic, which are nonpolar compounds originating from bacteria present in the residue. The acids groups in extract hexane also were evidenced by X-ray diffraction and FTIR.
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The ability to integrate multiple materials into miniaturized fiber structures enables the realization of novel biomedical textile devices with higher-level functionalities and minimally-invasive attributes. In this work, we present novel textile fabrics integrating unobtrusive multi-material fibers that communicate through 2.4 GHz wireless networks with excellent signal quality. The conductor elements of the textiles are embedded within the fibers themselves, providing electrical and chemical shielding against the environment, while preserving the mechanical and cosmetic properties of the garments. These multi-material fibers combine insulating and conducting materials into a well-defined geometry, and represent a cost-effective and minimally-invasive approach to sensor fabrics and bio-sensing textiles connected in real time to mobile communications infrastructures, suitable for a variety of health and life science applications.
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The aim of this study is to demonstrate through a case report, a proposed treatment for discolored teeth, with and without pulp vitality, by the technique of external and internal tooth bleaching with hydrogen peroxide to 35% Lase Peroxide Sensy (DMC) using Whitening Lase II Device (DMC), and a silicone guide (3M ESPE) in the palatine portion of the upper teeth. In this clinical case, the patient had darkened dental elements 11 and 22, and dissatisfaction with the coloring of other elements. It was observed that the techniques used and the materials chosen allowed for an excellent aesthetic result, with technical simplicity and low cost, and minimal occurrence of signs and symptoms
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Aim: This study investigated the flowability, setting time, pH, calcium release and bond strength of a MTA-based cement (MTA Fillapex®) compared to AH Plus and Sealapex. Materials and methods: For the flowability test, the ISO 6876:2001 specification was utilized and for the setting time test, the ASTM C266-03 specification was utilized. For the pH and calcium release measurements, 10 samples were prepared for each group and analyzed for several different periods. For the push-out test, dentin disks were distributed into three groups, according to the cement utilized and into three subgroups, according to the root third (n = 10). After obturation, the specimens underwent push-out testing. The data were compared statistically using a significance level of 5%. Results: The flowability of all materials was found to be similar (p > 0.05). The setting times were different among the groups tested (MTA Fillapex < Sealapex < AH Plus) (p < 0.05). At days 7 and 28, the MTA Fillapex presented the higher pH values (p < 0.05). At 24 hours and at 14 days, the calcium release of the MTA Fillapex was similar to that of Sealapex (p > 0.05). AH Plus presented the lowest pH and calcium release values (p < 0.05). In all root thirds, the adhesion to the dentin of the MTA Fillapex and Sealapex were significantly lower than that of AH Plus (p < 0.05). Conclusion: MTA Fillapex and Sealapex presented several similar properties and both were found to be different than AH Plus. Clinical significance: This study evaluated the physicochemical and mechanical properties of new MTA-based root canal cement, in order to use this scaler in root canal fillings. MTA Fillapex showed satisfactory properties for clinical use.
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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Effect of intracanal dressings on repair and apical bridging of teeth with incomplete root formation
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Periapical repair and apical bridging were studied in dog's teeth with incomplete root formation and induced chronic periapical lesions treated with different dressings. A total of 75 root canals from the upper and lower premolars of 4 dogs approximately 6 months of age were chemo-mechanically prepared and filled with the following dressings: antibacterial dressing consisting of a calcium hydroxide+camphorated p-monochlorophenol paste applied for 7 days and followed by monthly renewed calcium hydroxide paste as temporary dressing at 30, 60 and 90 days (Group A); antibacterial dressing consisting of camphorated p-monochlorophenol alone for 7 days, followed by temporary dressing with calcium hydroxide paste renewed at 30, 60 and 90 days (Group B). A control group (Group C) received no dressings. Ninety days after the last calcium hydroxide paste (Groups A, B) and after the last irrigation/aspiration (Group C), the animals were killed, the maxillae and mandibles were removed, and the material submitted to routine histological processing and examination. Both root canal dressings, were of fundamental importance for apical repair and bridging. The apical bridging was predominantly complete in Group A, incomplete in Group B, and absent in Group C. The calcium hydroxide+camphorated p-monochlorophenol combination gave better results than camphorated p-monochlorophenol alone.