Estudo sobre o efeito dos parâmetros de processamento dos pós e sinterização do aço inox 316l reforçado com NbC

This masther dissertation presents a contribution to the study of 316L stainless steel sintering aiming to study their behavior in the milling process and the effect of isotherm temperature on the microstructure and mechanical properties. The 316L stainless steel is a widely used alloy for their high corrosion resistance property. However its application is limited by the low wear resistance consequence of its low hardness. In previous work we analyzed the effect of sintering additives as NbC and TaC. This study aims at deepening the understanding of sintering, analyzing the effect of grinding on particle size and microstructure and the effect of heating rate and soaking time on the sintered microstructure and on their microhardness. Were milled 316L powders with NbC at 1, 5 and 24 hours respectively. Particulates were characterized by SEM and . Cylindrical samples height and diameter of 5.0 mm were compacted at 700 MPa. The sintering conditions were: heating rate 5, 10 and 15◦C/min, temperature 1000, 1100, 1200, 1290 and 1300◦C, and soaking times of 30 and 60min. The cooling rate was maintained at 25◦C/min. All samples were sintered in a vacuum furnace. The sintered microstructure were characterized by optical and electron microscopy as well as density and microhardness. It was observed that the milling process has an influence on sintering, as well as temperature. The major effect was caused by firing temperature, followed by the grinding and heating rate. In this case, the highest rates correspond to higher sintering.

Estudos de sinterização da mistura de pós cerâmicos diatomita-titânia

This work is part of an effort of consolidation of a daily search for powder technology at the Department of Physics of the Universidade Federal do Rio Grande do Norte. This work objective the study and development of new ceramic materials from raw materials abundant at the region. For this, were studied ceramic mixtures of powders from diatomite-titania to aiming at a new ceramic material from powder technology. The experimental work involved a characterization of ceramic powders from a diatomite-titania mixture. The powders obtained were pressed and then parameters like variation of mass, linear shrinkage, activation energy and the mechanism of sintering are studied in function of the time and temperature of sintering, beyond microstructural analysis. The obtained results allow us estimate the optimizing of sintering conditions of this material

Estudo sobre o efeito dos parâmetros de processamento dos pós e sinterização do aço inox 316l reforçado com NbC

This masther dissertation presents a contribution to the study of 316L stainless steel sintering aiming to study their behavior in the milling process and the effect of isotherm temperature on the microstructure and mechanical properties. The 316L stainless steel is a widely used alloy for their high corrosion resistance property. However its application is limited by the low wear resistance consequence of its low hardness. In previous work we analyzed the effect of sintering additives as NbC and TaC. This study aims at deepening the understanding of sintering, analyzing the effect of grinding on particle size and microstructure and the effect of heating rate and soaking time on the sintered microstructure and on their microhardness. Were milled 316L powders with NbC at 1, 5 and 24 hours respectively. Particulates were characterized by SEM and . Cylindrical samples height and diameter of 5.0 mm were compacted at 700 MPa. The sintering conditions were: heating rate 5, 10 and 15◦C/min, temperature 1000, 1100, 1200, 1290 and 1300◦C, and soaking times of 30 and 60min. The cooling rate was maintained at 25◦C/min. All samples were sintered in a vacuum furnace. The sintered microstructure were characterized by optical and electron microscopy as well as density and microhardness. It was observed that the milling process has an influence on sintering, as well as temperature. The major effect was caused by firing temperature, followed by the grinding and heating rate. In this case, the highest rates correspond to higher sintering.

A indústria petrolífera nacional e potiguar: uma análise a partir da tecnologia em E&P

O trabalho analisa a Indústria Petrolífera em três ambientes de atuação, mundial, nacional e estadual, a partir da observação de sete variáveis, a saber: caráter do petróleo; risco; economia de escala; integração; barreiras; tecnologia e ambiente. O estudo busca perceber as interações e os transbordamentos das variáveis selecionadas em cada um dos ambientes citados, em razão os aspectos econômicos e institucionais presentes nesta atividade, cujos resultados atingem diversos setores da economia e da sociedade como um todo e balizam o próprio processo de inovação da mesma. O estudo está alicerçado no arcabouço teórico neoschumpeteriano acerca dos aspectos voltados para concorrência e inovação, além da questão institucional, e se apóia em dados da Agência Nacional do Petróleo (A.N.P.), Ministério de Minas e Energia (MME), Movimento de Combate à Corrupção Eleitoral / Tribunal Superior Eleitoral (MCCE/TSE), Organization of the Petroleum Exporting Countries (OPEC), International Energy Agency (IAE), Institut Français Pétrole (IFP), United Nations Development Programme (UNDP). Avalia-se que em termos de caracterização da indústria petrolífera nos três ambientes considerados (mundial, nacional e local), há certa similitude no que se refere ao comportamento destas variáveis, com pequenas modificações suscitadas por fatores como grau de desenvolvimento e complexidade da atividade; resultado do ambiente concorrencial e inovativo; e, pelas influências institucionais acerca de atividades e grau de inserção das mesmas no ambiente socioeconômico onde estão localizadas a atividade produtiva e o seu entorno

A cientometria revisitada à luz da expansão da ciência, da tecnologia e da inovação

VANTI, Nadia. A cientometria revisitada à luz da expansão da ciência, da tecnologia e da inovação. PontodeAcesso, Salvador, v. 5, p. 5-31, 2011

Efeito da tecnologia de microondas nas propriedades tecnológicas dos componentes de cerâmica estrutural

O processamento térmico de materiais cerâmicos via energia de microondas, no estágio atual, vem ganhando cada dia mais importância, tendo em vista suas inúmeras aplicações, como por exemplo: aplicação de microondas na área de processamento mineral (aquecimento de minérios antes da moagem, secagem, redução carbotérmica de óxidos minerais, lixiviação, fusão, pré-tratamento de minérios e concentrados de ouro refratário, regeneração de carvão, etc. de acordo com Kigman & Rowson, 1998). Em virtude de uma série de vantagens em potencial, frente aos métodos convencionais de aquecimento, como redução no tempo de processamento; economia de energia; diminuição do diâmetro médio das partículas e melhoramento nas propriedades tecnológicas em geral, esta tecnologia vem se destacando. Neste contexto, o objetivo geral deste trabalho, é desenvolver uma pesquisa visando identificar e caracterizar novas opções de matérias-primas cerâmicas como argilas, feldspatos e caulins que sejam eficazes para definir a formulação de uma ou mais massas para produção de componentes de cerâmica estrutural com propriedades físicas, mecânicas e estéticas adequadas após passarem por sinterização convencional e por energia de microondas destacando as vantagens desta última. Além dos requisitos técnicos e de processo, as formulações apresentadas deverão atender às expectativas de preço e de logística de fornecimento. No estudo foram conformados corpos-de-prova por extrusão e prensagem, sinterizados em fornos microondas e convencional, sob ciclos de queima mais rápidos que os atualmente praticados. As matérias-primas foram caracterizadas e analisadas, utilizando as técnicas de fluorescência por raios X (FRX), difração por raios X (DRX), análise térmica diferencial (DTA), análise térmica gravimétrica (DTG), análise granulométrica (AG), microscopia eletrônica de varredura (MEV), absorção d agua (AA), massa especifica aparente (MEA), porosidade aparente (PA), retração linear (RL) e tensão de ruptura e flexão (TRF). Os resultados obtidos indicaram que as propriedades tecnológicas de Absorção de água (AA) e Tensão de Ruptura e flexão (TRF), proposto no trabalho foram adquiridos com sucesso e estão bem além do limite exigido pelas especificações das normas da ABNT NBR 15.270/05 e 15.310/09

Gestão compartilhada de P&D em petróleo:a interação entre a Petrobrás e a Universidade Federal do Rio Grande do Norte

This work addresses the relationship between University-Firm aims to understand the model of shared management of R&D in petroleum of Petrobras with UFRN. This is a case study which sought to investigate whether the model of cooperation established by the two institutions brings innovation to generate technical-scientific knowledge and contribute to the coordination with other actors in the promotion of technological innovation. In addition to desk research the necessary data for analysis were obtained by sending questionnaires to the coordinators of projects in R&D at the company and university. Also, interviews were conducted with subjects who participated in the study since its inception to the present day. This case study were analysed through the Resource-Based View and Interorganizational Networks theory. The sample data also stands that: searches were aligned to the strategic planning and that 29% of R&D projects have been successful on the scope of the proposed objectives (of which 11% were incorporated into business processes); which was produced technical and scientific knowledge caracterized by hundreds of national and international publications; thesis, dissertations, eleven patents, and radical and incremental innovations; the partnership has also brought benefits to the academic processes induced by the improved infrastructure UFRN and changing the "attitude" of the university (currently with national prominence in research and staff training for the oil sector). As for the model, the technical point of view, although it has some problems, it follows that it is appropriate. From the viewpoint of the management model is criticized for containing an excess of bureaucracy. From the standpoint of strategic allocation of resources from the legal framework needs to be reassessed, because it is focused only on the college level and it is understood that should also reach the high school given the new reality of the oil sector in Brazil. For this it is desirable to add the local government to this partnership. The set of information leads to the conclusion that the model is identified and named as a innovation of organizational arrangement here known as Shared Management of R&D in petroleum of Petrobras with UFRN. It is said that the shared management model it is possible to exist, which is a simple and effective way to manage partnerships between firms and Science and Technology Institutions. It was created by contingencies arising from regulatory stand points and resource dependence. The partnership is the result of a process of Convergence, Construction and Evaluation supported by the tripod Simplicity, Systematization and Continuity, important factors for its consolidation. In practice an organizational arrangement was built to manage innovative university-industry partnership that is defined by a dyadic relationship on two levels (institutional and technical, therefore governance is hybrid), by measuring the quarterly meetings of systematic and standardized financial contribution proportional to the advancement of research. These details have led to the establishment of a point of interaction between the scientific and technological-business dimension, demystifying they are two worlds apart

Tecnologia para banho no leito de idosos e usuários acamados: uma contribuição para o cuidar humanizado

This study aimed to validate the technology at Bed Bath System, in view of bedridden elderly and their caregivers, with a view to transforming the conventional paradigm regarding the practice of bodily hygiene held in bath chairs adapted in long-stay institutions for the elderly. This is an experimental study involving 51 (fifty one) elderly and 17 (seventeen) caregivers of three long-stay institutions for the elderly of the city of João Pessoa. For data collection, applied initially to cognitive assessment scale Mini Mental State Examination, with the aim of tracking the subject group of elderly cognitively able to participate in the study. In the second phase, to measure the percentage of agreement and disagreement about the attributes of the subjects of the shower chair and adapted the system for bed bath, used a questionnaire with closed questions, Likert scale model of four (4) points, with a good reliability index (0.728), estimated by alpha conbrach, evidenced by the Wilcoxon test a significant difference (P<0.05) between the responses of seniors and caregivers about the attributes involving technology system in bath bed and bath chair adapted, confirming the perspective of the subjects that the two systems differ significantly. However, the system bed bath got greater degree of agreement for their use, characterizing this system is a technology that makes the differential bed bath pleasurable action, quality and humanized

Automedicação e guarda de medicamentos por universitários das áreas de saúde e tecnologia

This study aimed to compare self-medication and domestic drug storage among undergraduate students in the areas of health and technology. This is a descriptive study of cross-sectional type and quantitative approach, conducted in a Public University of Natal, Rio Grande do Norte, Brazil. The sample consisted of 300 students of the third year of undergraduate courses at the Center for Health Sciences and Technology Center, selected through a simple random sample. The project was authorized by the Ethics Committee of Federal University of Rio Grande do Norte (CAAE 0137.0.051.000-10). Data collection lasted twelve months and was conducted during the period of study participants, in the university environment. The instrument for data collection was a structured questionnaire consisting of open and closed questions. For data analysis, we used descriptive statistics and applied Fisher s exact test and Chi-square test with adopted level of significance α=5% and 10%. For the variables that correlated with self-medication (p<0.05), we subsequently calculated the odds ratios and confidence intervals. The prevalence of undergraduate students who performed self-medication in the 15 days prior to the collection accounted for 33.7% and, by analyzing each knowledge area, we verified was a higher prevalence of self-medication among students in the technological area (37.3%). The analysis of the socio-demographic characteristics of the participants in this practice revealed a significant difference between the knowledge areas in the income and self-medication variables (p=0.005). General analgesics and antipyretics (N02) represent the therapy group most used in self-medication (57.4%), especially acetaminophen (28.7%), and the main health situations that motivated this practice related to pain, especially headaches (48.5%). Regarding the indication of the drugs used, the majority of students self-medicated themselves on their own (71.3%). As regards to the in-home drug storage, most of the participants had a home pharmacy (88%). By analyzing the socioeconomic characteristics, the variables medical service and home medicine presented a significant difference (p=0.002). General 10 analgesics and antipyretics constituted the medicinal products most found in the home pharmacies, especially acetaminophen. The main room used for the drug storage was the kitchen (36.4%), most students kept these products in boxes of different materials (38.6%) and the medicines stored at home of most of the participants were not easily accessible to children (75%). The results reinforce the need to develop strategies, from the reality found, aiming to encourage and implement educational and preventive activities with undergraduate students on the importance of proper self-medication and in-home drug storage. Despite the sample in our study is relatively small, not representative for the whole country, we believe that, at national level, the panorama of the subject does not present major differences

Influência da corrente de pulso, do tempo de pulso e diâmetro de gota sobre a estabilidade da transferência metálica no processo MIG-P

To obtain a process stability and a quality weld bead it is necessary an adequate parameters set: base current and time, pulse current and pulse time, because these influence the mode of metal transfer and the weld quality in the MIG-P, sometimes requiring special sources with synergistic modes with external control for this stability. This work aims to analyze and compare the effects of pulse parameters and droplet size in arc stability in MIG-P, four packets of pulse parameters were analysed: Ip = 160 A, tp = 5.7 ms; Ip = 300 A and tp = 2 ms, Ip = 350 A, tp = 1.2 ms and Ip = 350 A, tp = 0.8 ms. Each was analyzed with three different drop diameters: drop with the same diameter of the wire electrode; droplet diameter larger drop smaller than the diameter of the wire electrode. For purposes of comparison the same was determined relation between the average current and welding speed was determined generating a constant (Im / Vs = K) for all parameters. Welding in flat plate by simple deposition for the MIG-P with a distance beak contact number (DBCP) constant was perfomed subsequently making up welding in flat plate by simple deposition with an inclination of 10 degrees to vary the DBCP, where by assessment on how the MIG-P behaved in such a situation was possible, in addition to evaluating the MIG-P with adaptive control, in order to maintain a constant arc stability. Also high speed recording synchronized with acquiring current x voltage (oscillogram) was executed for better interpretation of the transfer mechanism and better evaluation in regard to the study of the stability of the process. It is concluded that parameters 3 and 4 exhibited greater versatility; diameters drop equal to or slightly less than the diameter of the wire exhibited better stability due to their higher frequency of detachment, and the detachment of the drop base does not harm the maintenance the height of the arc

Obtenção e caracterização de um compósito de poliuretano de mamona e pó de vidro para aplicações em insolantes térmicos

Thermal insulation is used to protect the heated or cooled surfaces by the low thermal conductivity materials. The rigid ricin polyurethane foams (PURM) are used for thermal insulation and depend on the type and concentration of blowing agent. Obtaining PURM occurs by the use of polyol, silicone, catalyst and blowing agent are pre -mixed, reacting with the isocyanate. The glass is reusable, returnable and recyclable heat insulating material, whose time of heat dissipation determines the degree of relaxation of its structure; and viscosity determines the conditions for fusion, operating temperatures, annealing, etc. The production of PURM composites with waste glass powder (PV) represents economical and renewable actions of manufacturing of thermal insulating materials. Based on these aspects, the study aimed to produce and characterize the PURM composites with PV, whose the mass percentages were 5, 10, 20, 30, 40 and 50 wt%. PURM was obtained commercially, while the PV was recycled from the tailings of the stoning process of a glassmaking; when the refining process was applied to obtain micrometer particles. The PURM + PV composites were studied taking into account the standard sample of pure PURM and the influence of the percentage of PV in this PURM matrix. The results of the chemical, physical and morphological characterization were discussed taking into account the difference in the microstructural morphology of the PURM+PV composites and the pure PURM, as well the results of the physicochemical, mechanical e thermophysical tests by values obtained of density, hardness, compressive strength, specific heat, thermal conductivity and diffusivity. In general, the structure of pure PURM showed large, elongated and regular pores, while PURM+PV composites showed irregular, small and rounded pores with shapeless cells. This may have contributed to reducing their mechanical strength, especially for PURM - PV50. The hardness and density were found to have a proportional relationship with the PV content on PURM matrix. The specific heat, thermal diffusivity and thermal conductivity showed proportional relationship to each other. So, this has been realized that the increasing the PV content on PURM matrix resulted in the rise of diffusivity and thermal conductivity and the decrease of the specific heat. However, the values obtained by the PURM composites were similar the values of pure PURM, mainly the PURM-PV5 and PURM-PV10. Therefore, these composites can be applied like thermal insulator; furthermore, their use could reduce the production costs and to preserve the environment

Tecnologia mais limpa para produção de mel seco de cana e sua inclusão em rações de frangos de corte

This study analyzed the effects of adding dry sugar cane molasses (MSC) to the feed of broiler chickens, and determining the economic feasibility of use of this type of diet; 240 male Ross race broiler chickens, one day in age, were utilized in this study. The experimental desing was a completely randomized whit 6 treatments and 4 replications, in 24 portions of 10 birds per parcel. The treatments corresponded to 6 rations (T1-T6) in phase initial (1-21 days) and 6 rations (T1-T6) in phasem finish (22-42 days) characterized by substitution of corn meal in levels increase 0, 5, 10, 15, 20 e 25% by the molasse dried sugar-cane. The birds received water and free ration during the whole creation phase, being the iso-proteins and iso-calories rations. The variance analysis showed the 1 a 21 days significant differences for average gain weight (P<0,05), average consumption of ration (P<0,05) and average alimentary conversion (P<0,05) and the 22 a 42 days, the analysis of variance showed significant differences for gain in weight (P<0,01) and average alimentary conversion (P<0,05). There no difference significant on average consumption of ration (P>0,05) the 22 a 42 days of age. Results showed out that is possible to use molasse dried sugar-cane up to 8,3 % in broilers ration. It was concluded the level of 8,3 % of addition gave the best economical returns in the experimental conditions

Passividade na interface prótese/pilar intermediário de infraestrutura implantossuportadas confeccionadas pela tecnologia CAD/CAM e método convencional

The objective of this research was to evaluate the passivity and strain induced in infrastructures screwed on abutments, made by CAD/CAM technology, and to compare these samples with parts manufactured by conventional casting. Using CAD/CAM technology, 4 samples were made from zirconia (Zircad) and 4 samples were manufactured from cobaltchrome (CoCrcad). The control groups were 4 specimens of cobalt-chrome, made by onepiece casting (CoCrci), for a total of 12 infrastructures. To evaluate the passivity, the infraestructures were installed on the abutments. One end was tightened and the vertical gap between the infrastructure and the prosthetic abutment was measured with scanning electron microscopy (250×). The mean strain in these infrastructures was analyzed via the photoelasticity test. A significant difference (p = 0.000) in passivity was observed between the control (CoCrci) and sample groups (CoCrcad and CoCrci). CoCrcad exhibited the best value of passivity (48.76 ± 13.45 μm) and CoCrci the worst (187.55 ± 103.63 μm), Zircad presented an intermediate value (103.81 ± 43.15 μm). When compared to the other groups, CoCrci showed the highest mean strain around the implants (17.19 ± 7.22 kPa). It was concluded that the zirconia infrastructure made by CAD / CAM showed a higher vertical marginal misfit than those made in cobalt-chromium alloy with the same methodology, however, the tension generated in the implants was similar. The CAD/CAM technology is more accurate for passivity and mean strain of infrastructure screwed on abutments than conventional manufacturing techniques

Tecnologia educacional no contexto do ensino de histologia: pesquisa e desenvolvimento de um ambiente virtual de ensino e aprendizagem

Discutem-se as mudanças constatadas no ensino da Histologia, como a tecnologia tem sido empregada nos contextos de aprendizagem, os aspectos pedagógicos inerentes à utilização de recursos, tais como atlas digitais e microscópios virtuais, e apresenta-se pesquisa sobre o desenvolvimento de um ambiente virtual de ensino-aprendizagem de Histologia, que contou com a participação de alunos e professores em sua construção. Verificou-se que os ambientes virtuais e outros recursos didáticos baseados nas Tecnologias da Informação e da Comunicação (TICs) procuram atender à atual tendência de complementar a educação presencial com ferramentas de educação a distância, que podem ser utilizadas facultativamente no estudo extraclasse continuado. Concluiu-se que, embora as novas tecnologias possam contribuir para o ensino de Histologia, os materiais didáticos baseados em TICs devem se adequar às expectativas docentes e discentes e aos aspectos pedagógicos e ergonômicos, e precisam ser adotados pelos professores não como ferramentas isoladas, mas integrados às estratégias de ensino- -aprendizagem

O papel da tecnologia cênica e seus desdobramentos para uma economia da produção cultural no nordeste

O papel da tecnologia na produção contemporânea em artes cênicas vem influenciando profundamente as formas de recepção e produção de Teatro, Dança, espetáculos de Circo, shows musicais, entre outras manifestações espetaculares organizadas. Sua aplicação se estende amplamente a outras áreas que necessitam enfatizar o caráter cênico de seus processos de fruição como é o caso dos museus, feiras de ciências, exibições e mostras em artes visuais e o aparato tecnológico de luz, som e configuração espacial usados para estes fins. Neste sentido, o desenvolvimento deste tipo de tecnologia vem gerando e alimentando cadeias produtivas que movimentam uma economia da produção cultural e criam uma rede de relações articuladas em diferentes níveis de atuação, envolvendo produtores de equipamento, fornecedores, lighting designers, cenógrafos, profissionais de sonorização, arquitetos, técnicos de montagem e operação, instituições ensino especializadas, associações de área, entre outros. O foco deste trabalho se concentra em demonstrar como a análise de demandas de tecnologia cênica articuladas pelos sistemas de produção cultural, em particular na região Nordeste do Brasil, possibilitam compreender modelos de organização em curso, contribuindo para o desenvolvimento de uma reflexão multidisciplinar acerca dos processos de produção artística de natureza cênica e como esta produção é afetada pelos limites e possibilidades dos aspectos que caracterizam uma economia destas produções