924 resultados para Technological improvements


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Plasma immersion ion implantation (PIII) process is a three dimensional surface modification method that is quite mature and well known to the surface engineering community nowadays, especially to those working in the field of plasma-materials interaction, aiming at both industrial and academic applications. More recently, deposition methods have been added to PIII, the PIII&D, opening possibilities of broader range of applications of these techniques. So, PIII&D is becoming a routine method of surface modification, with the advantage of pushing up the retained dose levels limited by the sputtering due to ion implantation. Therefore, well adherent, thick, three-dimensional films without stress are possible to be achieved, at relatively low cost, using PIII&D. In this paper, we will discuss about a few PIII and PIII&D experiments that have been performed recently to achieve surface improvements in different materials: 1 - high temperature nitrogen PIII in Ti6Al4V alloy in which a deep nitrogen rich treated layer resulted in surface improvements as increase of hardness, corrosion resistance and resistance to wear of the Ti alloy; 2 - nanostructures in ZnO films, obtained by PIII&D of vaporized & ionized Zn source; 3 - combined implantation and deposition of calcium for biomaterial activity of Ti alloy (PIII&D), allowing the growth of hydroxyapatite in a body solution; 4 - magnetron sputtering deposition of Cr that was enhanced by the glow discharge Ar plasma to allow implantation and deposition of Cr on SAE 1070 steel (PIII&D) resulting in surfaces with high resistance to corrosion; and 5 - implantation of nitrogen by ordinary PIII into this Cr film, which improved resistance to corrosion, while keeping the tribological properties as good as for the SAE 1070 steel surface. © 2012 Elsevier B.V.

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The construction of synthetic cells is one of the major goals of bioengineering. The most successful approach consists in the encapsulation of biochemical materials (DNA, RNA, enzymes, etc.) inside lipid vesicles (liposomes), mimicking a cell structure. In this contribution, that also aims at introducing the reader to 'chemical synthetic biology,' we describe the current state of the art of 'semi-synthetic minimal cells' (SSMCs), namely, cell-like structures containing the minimal number of biological compounds that are required to reconstruct a function of interest. We will first describe how the concept of the minimal cell was originated and its relation with the theory of autopoiesis, then we review the most advanced results focused on genetic/metabolic networks inside liposomes. Next, we emphasize that relevance of physical aspects (too often neglected) that impact on the solute entrapment process, and finally we discuss new technological trends in SSMC research that will probably allow their future use in biotechnology. © 2013 Copyright © 2013 Elsevier Inc. All rights reserved.

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The aim of the present study was to analyze the effects of age on cardiorespiratory fitness (CRF), muscle strength and heart rate (HR) response to exercise adaptation in women in response to a long-term twice-weekly combined aerobic and resistance exercise program. 85 sedentary women, divided into young (YG; n=22, 30.3±6.2 years), early middle-aged (EMG; n=28, 44.1±2.5 years), late middle-aged (LMG; n=20, 56.7±3.5 years) and older (OG; n=15, 71.4±6.9 years) groups, had their CRF, muscle strength (1-repetition maximum test) and HR response to exercise (graded exercise test) measured before and after 12 months of combined exercise training. Exercise training improved CRF and muscle strength in all age groups (P<0.05), and no significant differences were observed between groups. Exercise training also improved resting HR and recovery HR in YG and EMG (P<0.05), but not in LMG and OG. Maximal HR did not change in any group. Combined aerobic and resistance training at a frequency of 2 days/week improves CRF and muscle strength throughout the lifespan. However, exercise-induced improvements in the HR recovery response to exercise may be impaired in late middle-aged and older women. © Georg Thieme Verlag KG.

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Contiene discurso de inauguración, presentación y comentario de los documentos presentados y recomendaciones de la reunión en que se trataron las opciones tecnológicas para el desarrollo de las industrias del aluminio en América Latina y el Caribe.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Includes bibliography

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)