983 resultados para Isostatic pressing.
Resumo:
O presente relatório reporta-se ao estágio de intervenção comunitária, decorrido entre 16/9/2013 e 31/01/2014, na população idosa da Freguesia de Tramaga, Concelho de Ponte de Sor, Distrito de Portalegre, parte integrante de uma das regiões mais envelhecidas do país: Alto Alentejo. Constitui-se como instrumento para avaliação da manifesta Unidade Curricular, título de Mestre em Enfermagem e validar competências para atribuição do título de Enfermeiro Especialista em Enfermagem Comunitária e Saúde Pública pela Ordem dos Enfermeiros. A Intervenção Comunitária sustentou-se com base na metodologia do planeamento em saúde, metodologia de referência no âmbito da aquisição de competências da especialidade em Enfermagem Comunitária e Saúde Pública (Regulamento n.º 128/2011), das quais se distinguem capacidades para trabalhar em parceria com as comunidades, reconhecer as suas necessidades, planear cuidados adequados aos seus problemas mais prementes, enfatizar práticas conducentes a comportamentos e estilos de vida saudáveis, adotando a promoção da saúde e o empowerment como pedra basilar de intervenção. As intervenções dirigiram-se para os problemas priorizados, designadamente: quedas, comorbilidades, depressão, obesidade, polifarmácia e vulnerabilidades como: Viver só, isolamento, iliteracia e condição de habitação. Os objetivos gerais subjacentes tinham como desígnio sensibilizar população idosa e entidades políticas/locais/concelhias, sobre os problemas de saúde que influenciam negativamente a qualidade de vida destes idosos; contribuir para a sua minimização e melhoria da qualidade de vida, através de abordagens educativas, no âmbito de comportamentos e estilos de vida saudáveis, perspetivando o seu empowerment. Na sinergia entre Mestrandas, comunidade e organizações políticas/locais/concelhias houve possibilidade de discutir e analisar soluções para alguns problemas identificados. Foram desenvolvidas atividades de educação em saúde: ‘atelier da saúde’; Fórum comunitário; Sessão ‘Segurança do idoso’ (em parceria estratégica de ampliação de eficácia com GNR e Teleassistência); todas tiveram o cunho interativo da comunidade. Foram aditadas estratégias de transmissão e disponibilização de informação no domínio de comportamentos e adoção de estilos de vida saudáveis, difundida por panfletos e meios de comunicação social local, configurando complementaridade com ações educativas.Supõe-se que as ações desenvolvidas alteraram comportamentos e contribuíram para a melhoria da qualidade de vida dos idosos, uma vez que estimulam a participação, interação, integração e perspetivam o empowerment
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At present, the material of choice for performing aesthetic dental prosthetic work is in the ceramic. Among them, the ceramic base of stabilized zirconia with 3% yttria (3Y - TZP) stand out for having excellent physical and mechanical properties. During the machining of blocks of zirconia in the laboratory to prepare the various types of prostheses, much of the material is given off in the form of powder, which is subsequently discarded. The waste of this material results in financial loss, reflecting higher final cost treatment for patients, as well as damage to the environment, thanks to the processes involved in the manufacture and disposal of the ceramic. This research, pioneered the recycling of zirconium oxide powder obtained during milling of dental crowns and bridges, we highlight the social and environmental aspects and aims to establish a protocol for the reuse of waste (powder of zirconia Zirkonzahn® system) discarded to obtain a new block of compacted zirconia to maintain the same mechanical and microstructural properties of commercial high-cost imported material. To compare with the commercial material, samples were uniaxially (20 MPa) and isostatically (100 MPa), and its mechanical and microstructural characterization was performed through tests of density, porosity, dilatometry, X-ray diffraction (XRD), hardness, fracture toughness, resistance to fracture electron microscopy (SEM) and analysis of grain size. The results observed in the samples were isostatically pressed similiares those obtained with samples from the commercial material demonstrating the viability of the process
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Heating rate is one of the main variables that determine a fire cycle. In industrial processes that use high temperatures, greater fire great can reduce the cost of production and increase productivity. The use of faster and more efficient fire cycles has been little investigated by the structural ceramic industry in Brazil. However, one of the possibilities that aims at modernizing the sector is the use of roller kilns and the inclusion of natural gas as fuel. Thus, the purpose of this study is to investigate the effect of heating rate on the technological properties of structural ceramic products. Clay raw materials from the main ceramic industries in the state of Rio Grande do Norte were characterized. Some of the raw materials characterized were formulated to obtain the best physical and mechanical properties. Next, raw materials and formulations were selected to study the influence of heating rate on the final properties of the ceramic materials. The samples were shaped by pressing and extrusion and submitted to rates of 1 °C/min, 10 °C/min and 20 °C/min, with final temperatures of 850 °C, 950 °C and 1050 °C. Discontinuous cycles with rates of 10 °C/min or 15 °C/min up to 600 °C and a rate of 20 °C/min up to final temperature were also investigated. Technological properties were determined for all the samples and microstructural analysis was carried out under a number of fire conditions. Results indicate that faster and more efficient fire cycles than those currently in practice could be used, limiting only some clay doughs to certain fire conditions. The best results were obtained for the samples submitted to slow cycles up to 600 °C and fast fire sinterization up to 950 °C. This paper presents for the first time the use of a fast fire rate for raw materials and clay formulations and seeks to determine ideal dough and processing conditions for using shorter fire times, thus enabling the use of roller kilns and natural gas in structural ceramic industries
Resumo:
Rio Grande do Norte State stands out as one great producer of structural clay of the brazilian northeastern. The Valley Assu ceramic tiles production stands out obtained from ilitics ball clays that abound in the region under study. Ceramics formulation and the design of experiments with mixture approach, has been applied for researchers, come as an important aid to decrease the number of experiments necessary to the optimization. In this context, the objective of this work is to evaluate the effects of the formulation, temperature and heating rate in the physical-mechanical properties of the red ceramic body used for roofing tile fabrication of the Valley Assu, using design of mixture experiments. Four clays samples used in two ceramics industry of the region were use as raw material and characterized by X-ray diffraction, chemical composition, differential thermal analysis (DTA), thermogravimetric analysis (TGA), particle size distribution analysis and plasticity techniques. Afterwards, they were defined initial molded bodies and made specimens were then prepared by uniaxial pressing at 25 MPa before firing at 850, 950 and 1050 ºC in a laboratory furnace, with heating rate in the proportions of 5, 10 e 15 ºC/min. The following tecnologicals properties were evaluated: linear firing shrinkage, water absorption and flexural strength. Results show that the temperature 1050 ºC and heating rate of 5 ºC/min was the best condition, therefore presented significance in all physical-mechanical properties. The model was accepted as valid based of the production of three new formulations with fractions mass diferents of the initial molded bodies and heated with temperature at 1050 ºC and heating rate of 5 ºC/min. Considering the formulation, temperature and heating rate as variables of the equations, another model was suggested, where from the aplication of design of experiments with mixtures was possible to get a best formulation, whose experimental error is the minor in relation to the too much formulations
Resumo:
The state of Rio Grande do Norte presents a great potentiality for the production of ceramic tiles because of having natural raw material in quantity and quality making its economical exploration possible, beyond the great energetic differential of the state, the natural gás. This works aims to study the influence of the dolomite and granulometry concentration and calcinations temperature in the obtaining of formulations for porous coverings which have to be coherent to the project,s specifications. The experiments have involved the physical-chemical and mineralogical characterizations of raw materials and mechanical tests in the dry and burnt proof bodies preceding a mixture experiment planning with the use of the response surface methodology, in order to get the best raw materials combinations to produce a ceramic mass with specific properties. The twelve ceramic masses studied in this work were prepared by the via dry process, characterized, shaped by uniaxial pressing and sinterized in the temperatures of 940ºC, 1000ºC, 1060ºC, 1120ºC and 1180ºC, using a fast burning cycle. The crystalline phases formed during the sintering in the temperatures in study have revealed the presence of anorthite and diopside beyond quartz with a remaining phase. These phases were the main responsible ones by the physical- mechanical properties of the sinterized proof bodies. The proof bodies after the sintering stage have presented water absorption higher than 10% and a good dimensional stability in all studied temperatures. However, the flexural breaking strength results in the temperatures of 940ºC, 1000ºC and 1060ºC, under the temperature zone of the vitrification of ceramic whiteware do not reach the flexural breaking strength specific for the porous wall tile (15 MPa), but in the temperature of 1120ºC next to the vitrification temperature zone, some whiteware ceramic (formulations) has reached the specified value for the porous wall tile. The results of this work have showed that the studied raw materials have great importance for used in the production of porous wall tiles (BIII)
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Many mental disorders are characterised by the presence of compulsions and incontrollable habits. Most studies on habit learning, both in animals and in humans, are based on positive reinforcement paradigms. However, the compulsions and habits involved in some mental disorders may be better understood as avoidance behaviours, which involve some peculiarities, such as anxiety states, that have been shown to promote habitual responses. Consequently, we studied habit acquisition by using a free-operant discriminated avoidance procedure. Furthermore, we checked whether intolerance of uncertainty could predispose to avoidance habit acquisition. Participants learned to avoid an aversive noise presented either to the right or to the left ear by pressing two different keys. After a devaluation phase where the volume of the noise presented to one of the ears was reduced, participants went through a test phase identical to the avoidance learning phase except for the fact that the noise was never administered. Habit acquisition was inferred by comparing the rate of responses to the stimulus signalling the devalued reinforcer and to the stimulus signalling the non-devalued reinforcer. The results showed that intolerance of uncertainty was related to the absence of differences between the referred conditions, which entail avoidance habit acquisition.
Resumo:
In contemporary education policy, simplified technical accounts of policy problems and solutions are being produced with the use of numeric calculations. These calculations are seen as clear and unbiased, capable of revealing ‘‘what works’’ and identifying ‘‘best practices.’’ In this piece, the authors use resources from the materialsemiotic approach of actor-network theory to discuss how calculations have begun to serve as a subtle infrastructure underpinning the way we understand and organise our world. They demonstrate the usefulness of the approach in tracing the technicisation of policy by deploying it to qualitative studies of like-school comparisons in the two unexpectedly linked locations—New York City and Australia. The authors reveal how technical accounts are precarious and need constant maintenance to endure, even as they increasingly becoming routine, curtailing the policy imagination and limiting the spaces of contestation. It is for this reason, they argue, that a deeper understanding and sustained critique of such accounts is of pressing importance.
Resumo:
This work is part of a general effort to demonstrate the effect of the bulk microstructure of titanium as a model bone implant material on viability of osteoblasts (bone-forming cells). The objective of this work was to study the proliferation of preosteoblastic MC3T3-E1 cells extracted from mice embryos on commercial purity titanium substrates. Two distinct states of titanium were considered: as-received material with an average grain size of 4.5 microm and that processed by equal channel angular pressing (ECAP), with an average grain size of 200 nm. We report the first results of an in vitro study into the effect of this extreme grain refinement on viability and proliferation of MC3T3-E1 cells. By means of MTT assays it was demonstrated that ECAP processing of titanium enhances MC3T3-E1 culture proliferation in a spectacular way. This finding suggests that bone implants made from ECAP processed titanium may promote bone tissue growth.
Resumo:
In the early 2000s the Orchestre Symphonique de Montréal (OSM), one of Montreal's foremost cultural institutions, underwent two upheavals. First management was thrown into turmoil by the unexpected departure of the OSM's celebrated music director, Charles Dutoit, just as the orchestra and its Swiss conductor were about to mark 25 years of successful partnership with celebrations planned for the 2002-03 season. Then, in May 2005, the orchestra's management and board were faced with a strike by the orchestra's musicians. The authors describe the efforts of the orchestra's general manager, Madeleine Careau, to revive its fortunes, notably through a campaign to restore the OSM's prestige, which had been severely eroded by these two events. With the support of internal and external collaborators, Careau turned her attention to the most pressing issues, namely the choice of a new conductor, the orchestra's planned new concert hall and the creation of a foundation to ensure stable, long-term financing for the OSM. To help bring this recovery plan to fruition, Careau drew on her extensive network of contacts. An all-female leadership team was formed at the OSM, as Careau called on Melanie La Couture (CEO), Helene Desmarais (deputy board chair) and Monique Jérôme-Forget (chair of the Quebec treasury board) to use their talents, expertise and influence to give new lustre to the OSM at home and abroad.
Resumo:
Samples of electrolytic tough pitch (ETP) pure copper were subjected to 12 passes of Equal-Channel Angular Pressing (ECAP) at room temperature with and without back pressure. Subsequent annealing was performed to evaluate the influence of back pressure during ECAP on the thermal behavior of ultrafine-grained copper. The microstructural and hardness changes caused by annealing were characterized by orientation imaging microscopy (OIM) and microhardness measurements. The application of back pressure resulted in an earlier drop in hardness upon annealing, which is believed to be associated with a lower critical temperature for the initiation of recrystallization and a rapid coarsening of microstructure. Regardless of whether back pressure was applied or not, structure coarsening during short-time annealing of ECAP-processed copper was governed by discontinuous static recrystallization. This is seen as a result of microstructure heterogeneity. Analysis of recrystallization kinetics was carried out based on observations of the microstructure after annealing in terms of the Avrami equation. The magnitude of the apparent activation energies for recrystallization in the absence of back pressure and in the case of back pressure of 100 MPa was estimated to be ~99 kJ/mol and ~91 kJ/mol, respectively. The reasons for reduced activation energy in the case of processing with back pressure are discussed.
Resumo:
Aims
To compare illness and treatment perceptions between Arabic-speaking immigrants and Caucasian English-speaking people with type 2 diabetes, and explore the relationships between these beliefs and adherence to self-care activities.
Methods
A cross-sectional study was conducted in healthcare settings with large Arabic populations in metropolitan and rural Victoria, Australia. Adherence to self-care activities, illness and treatment perceptions, and clinical data were recorded. Bivariate associations for continuous normally distributed variables were tested with Pearson's correlation. Non-parametric data were tested using Spearman's rank correlation coefficient.
Results
701 participants were recruited; 392 Arabic-speaking participants (ASPs) and 309 English-speaking participants (ESPs). There were significant relationships between participants’ illness and treatment perceptions and adherence to diabetes self-care activities. ASPs’ negative beliefs about diabetes were strongly and significantly correlated with poorer adherence to diet recommendations, exercise, blood glucose testing and foot care. ASPs were significantly less adherent to all aspects of diabetes self-care compared with ESPs: dietary behaviours (P = <0.01; 95% confidence interval (CI) = −1.17, −0.84), exercise and physical activity (P = <0.001, 95% CI −1.14, −0.61), blood glucose testing (P = <0.001) and foot-care (P = <0.001). 52.8% of ASPs were sceptical about prescribed diabetes treatment compared with only 11.2% of the ESPs. 88.3% of ASPs were non-adherent to prescribed medication, compared with 45.1% of ESPs.
Conclusions
Arabic-speaking migrants’ illness and treatment perceptions were significantly different from the English-speaking group. There is a pressing need to develop new innovative interventions that deliver much-needed improvements in adherence to self-care activities and key health outcomes.
Resumo:
Flow lines were analysed in aluminium alloy 6061 during equal channel angular extrusion (ECAE) in a 90° die with and without the application of back pressure during pressing. The lines appeared much more rounded when a back pressure was applied compared to the case of conventional ECAE testing. With the help of an analytic flow function, the deformation field was obtained. It is shown that back pressure slightly lowers the total strain, strongly increases the size of the plastic zone and significantly reduces the plastic strain rate.
Resumo:
Surface modification techniques are widely used to enhance the biological response to the implant materials. These techniques generally create a roughened surface, effectively increasing the surface area thus promoting cell adhesion. However, a negative side effect is a higher susceptibility of a roughened surface to failure due to the presence of multiple stress concentrators. The purpose of the study reported here was to examine the effects of surface modification by sand blasting and acid-etching (SLA) on the microstructure and fatigue performance of coarse-grained and ultrafine-grained (UFG) commercially pure titanium. Finer grain sizes, produced by equal channel angular pressing, resulted in lower values of surface roughness in SLA-processed material. This effect was associated with greater resistance of the UFG structure to plastic deformation. The fatigue properties of UFG Ti were found to be superior to those of coarse-grained Ti and conventional Ti-6Al-4V, both before and after SLA-treatment.
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Proton transport has been recognized as an essential process in many biological systems, as well as electrochemical devices including fuel cells and redox flow batteries. In the present study, we address the pressing need for solvent-free proton conducting polymer electrolytes for high-temperature PEM fuel cell applications by developing a novel all-solid polyelectrolyte membrane with a self-assembled proton-channel structure. We show that this self-assembled nanostructure endows the material with exciting ‘dry’ proton conductivity at elevated temperatures, as high as 0.3 mS cm−1 at 120 °C, making it an attractive candidate for high-temperature PEM fuel cell applications. Based on the combined investigation of solid-state NMR, FTIR and conductivity measurements, we propose that both molecular design and nano-scale structures are essential for obtaining highly conductive anhydrous proton conductors.
Resumo:
Application of damage model in combination with finite element analysis to design and optimization of equal channel angular pressing - conform of commercially pure titanium against ductile failure is demonstrated. The properties required for precise simulation of the process and prediction of damage accumulation (equivalent stress as function of equivalent strain and temperature and low bound ductility function) are obtained in the temperature interval 20-400 °C and described in details.