130 resultados para Isostatic pressing.


Relevância:

10.00% 10.00%

Publicador:

Resumo:

How do we engage with the pressing challenges of xenophobia, radicalism and security in the age of the "war on terror"? The widely felt sense of insecurity in the West is shared by Muslims both within and outside Western societies. Growing Islamic militancy and resulting increased security measures by Western powers have contributed to a pervasive sense among Muslims of being under attack (both physically and culturally). Islam and Political Violence brings together the current debate on the uneasy and potentially mutually destructive relationship between the Muslim world and the West and argues we are on a dangerous trajectory, strengthening dichotomous notions of the divide between the West and the Muslim world.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Chronic hepatitis C virus (HCV) infection is a major burden on humanity. The current HCV therapy has limited efficacy, and there is pressing need for new and more effective therapies. Host cell factors that are required for HCV infection, replication and/or pathogenesis represent potential therapeutic targets. Of particular interest are cellular receptors that mediate HCV entry, factors that facilitate HCV replication and assembly, and intracellular pathways involving lipid biosynthesis, oxidative stress and innate immune response. A crucial challenge now is to manipulate such cellular targets pharmacologically for chronic HCV treatment, without being limited by side effects.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

he microstructural evolution is examined during the hot compression of magnesium alloy AZ31 for both wrought and as-cast initial microstructures. The influences of strain, temperature, and strain rate on the dynamically recrystallized microstructures are assessed. Both the percentage dynamic recrysallization (DRX) and the dynamically recrystallized grain size were found to be sensitive to the initial microstructure and the applied deformation conditions. Lower Z conditions (lower strain rates and higher temperatures) yield larger dynamically recrystallized grain sizes and increased percentages of DRX, as expected. The rate with which the percentage DRX increases for the as-cast material is considerably lower than for the wrought material. Also, in the as-cast samples, the percentage DRX does not continue to increase toward complete DRX with decreasing Z. These observations may be attributed to the deformation becoming localized in the DRX fraction of the material. Also, the dynamically recrystallized grain size is generally larger in as-cast material than in wrought material, which may be attributed to DRX related to twins and the inhomogeneity of deformation. Orientation maps of the as-cast material (from electron backscattering diffraction (EBSD) data) reveal evidence of discontinuous DRX (DDRX) and DRX related to twins as predominant mechanisms, with some manifestation of continuous DRX (CDRX) and particle-stimulated nucleation (PSN).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Manufactured cellular aluminums have been developed for a wide range of automotive applications where weight savings, improved safety, crashworthiness and comfort are required. The plateau deformation behavior of cellular aluminums under compressive loading makes this new class of lightweight materials suitable for energy absorption and comes close to ideal impact absorbers. In the present study, aluminum hollow hemispheres were firstly processed by pressing. Hollow sphere aluminum samples with a body-centered cubic (BCC) packing were then fabricated by bonding together single hollow spheres, which were prepared by adhering together hollow hemispheres. Hollow sphere aluminum samples with various kinds of sphere wall thicknesses of 0.1 mm, 0.3 mm and 0.5 mm but the same outside diameter of 4 mm were investigated by compressive tests. The effects of the sphere wall thickness on the mechanical properties and energy absorption characteristics were investigated.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Hollow sphere metallic foams are a new class of cellular material that possesses the attractive advantages of uniform cell size distribution and regular cell shape. These result in more predictable physical and mechanical properties than those of cellular materials with a random cell size distribution and irregular cell shapes. In the present study, single aluminum hollow spheres with three kinds of sphere wall thickness as 0.1 mm, 0.3 mm and 0.5 mm were processed by a new pressing method. Hollow sphere aluminum foam samples were prepared by bonding together single hollow spheres with simple cubic packing (SC) and body-centered cubic packing (BCC). Compressive tests were carried out to evaluate the deformation behaviors and mechanical properties of the hollow sphere aluminum foams. Effects of the sphere wall thickness and packing style on the mechanical properties were investigated.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

There exist many web design methodologies and the new ones are constantly being added to the pool of those offered to practitioners. However as previous research shows, practitioners either do not know, do not use or even do not care for these development approaches. This paper examines web design practice, and the design of visual aspects in particular, in order to establish whether any of the existing methodologies would actually address the practitioners concerns. Through grounded theory analysis, it transpires that from amongst several examined approaches, IS-based web design methods are dealing with great many practical issues which designers perceive as most pressing.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Contemporary feminism has, from its inception, been ambivalent in its responses to the issue of women in management. On the one hand, feminists have recognised as a problem the limited numbers of women in management and the barriers that they encounter. They have promoted the development of programs such as affirmative action with, arguably, greater, or lesser success. At the same time, there has been a reluctance by some feminists to attach too much importance to the issue, given the manifestly more severe forms of discrimination encountered by other groups of women. According to this view, the problems of a privileged elite are a lesser priority, that is, marginal to more pressing feminist concerns.

This paper is based on research into career success predictors. It draws on work on culture and models of change in higher education to show that while interventions such as legislation granting maternity leave are significant initiatives to be strongly supported, the impact of such policies is mediated by the social rules of the organisation. These rules are a corollary of enduring value structures which are embedded in organisational cultures.

Research findings showed that the value systems, and especially the social rules which operate within organisations impact on men and women's career success differently. This research provides valuable insights into the mechanisms operating at several levels (at the organisational level as well as at the level of individual women) which tend to construct women as marginal in management.

Seeking to understand the marginality experienced by women in management has benefits that extend well beyond improving the lot of individual women managers. This is because better conceptualisations of marginality and, concomitantly, power in organisations can provide leverage for more far reaching changes for women generally.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

How do we engage with the pressing challenges of xenophobia, radicalism and security in the age of the "war on terror"? The widely felt sense of insecurity in the West is shared by Muslims both within and outside Western societies. Growing Islamic militancy and resulting increased security measures by Western powers have contributed to a pervasive sense among Muslims of being under attack (both physically and culturally). Islam and Political Violence brings together the current debate on the uneasy and potentially mutually destructive relationship between the Muslim world and the West and argues we are on a dangerous trajectory, strengthening dichotomous notions of the divide between the West and the Muslim world.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

One of the most pressing problems for contemporary school education is an overcrowded curriculum. The so-called 'National Curriculum' developed as a result of the Australian Education Council's Hobart meeting in 1989 and the subsequent publication of a series of 'Statements' and 'Profiles' by the Curriculum Corporation in 1994 consolidated the school curriculum into eight Key Learning Areas (Curriculum Corporation 1994a, 1994b). Since that time most states have moved away from school-based curriculum development and have embraced the National Curriculum but with adaptations to suit their own needs. In the case of Victoria there have been two iterations of the National Curriculum in the form of Curriculum and Standards Frameworks. In the original version, Music was one of the five arts strands specified for years P to 6 and one of the six strands for years 7 to 12 (Board of Studies 1995). With the CSF2, Music is now one of three possible arts form included under Performing Arts which, with Visual Arts, form the two strands specified for years P to 4 (Board of Studies 2000). Music is then included in its own right as one of six Arts strands for years 5 to 12. However, effectively the CSF2 represents a significant loss of ground for Music at the lower and middle primary school levels in Victoria.


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Aluminum alloy 6082 was subjected to equal-channel angular pressing (ECAP), which resulted in an ultra-fine-grained (UFG) microstructure with an average grain size of 0.2–0.4 μm. There was a pronounced effect of the grain refinement on the strain-rate sensitivity and tensile ductility. The Hart criterion of tensile necking fails to explain the observed ductility of the UFG material at low strain rates. A correlation between the observed stronger-than-expected ductility and a tendency to microshear band formation at low strain rates was established.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this study, superfine wool powder was plasticized with glycerol and hot-pressed into a film. Scanning electron microscopy photos showed that the superfine wool powder could be molded into a smooth film and that the wool powder was distributed evenly in the cross section of the film. Fourier transform infrared analysis revealed no substantial changes in the chemical structure of the wool powder after hot pressing, but the absorbing peaks of glycerol were found in the spectrum. X-ray diffraction analysis showed that the overall crystallinity increased after the wool powder was hot-pressed into film. Thermogravimetry (TG) analysis indicated that the thermal stability of the hot-pressed film decreased. A transition point appeared in the TG curve of the wool hot-pressed film as glycerol was added. The differential thermal analysis curve of the film showed sharp absorbing peaks similar to that of wool powder. With increasing glycerol content, the film showed increasing ductility and softness.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This work investigates the relationship between the strain rate and the ductility and the underlying deformation mechanisms in an ultrafine-grained Al6082 alloy. At room temperature the uniform elongation of the material exhibits a marked increase with decreasing strain rate. This effect is related to the activation of micro shear banding, which is controlled by grain boundary sliding. The contribution of these mechanisms to uniform elongation is estimated. It is proposed that the grain boundary sliding suppresses the transformation of micro shear bands into macro shear bands. The activity of other deformation mechanisms during plastic deformation of the ultrafine-grained material is also discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This work focuses on the effect of strain rate on the deformation behaviour of an ultrafine grained Al alloy 6082 produced by equal channel angular  pressing. The uniform tensile elongation was found to increase with  decreasing strain rate very substantially. This effect is discussed in terms of the mechanisms that control plastic deformation of the alloy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fibers based regenerated protein draw much attention for recycling discarded protein resources and can produce biodegradable and environmental friendly polymers. In this study, superfine wool powder is blended with polypropylene (PP) to produce wool powder/PP blend film through extrusion and hot-pressing. Hydrogen peroxide is used to bleach the black colored surface of the blend films. The effects of peroxide concentration, bleaching time and powder content on the final whiteness and mechanical properties of the blend films are investigated.

The bleached films are dyed with acid red dyes and the dyed color is evaluated using a Computer Color Matching System. Color characters of dyed films, such as L*, a*, b*, ΔE*ab, C*ab and K/S values are measured and analyzed. The study not only reuses discarded wool resources into organic powder, widens the application of superfine wool powder on polymers, but also improves the dyeing properties of PP through the addition of protein content.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The high baseline prevalence of overweight highlighted the pressing need for interventions like Be Active Eat Well (BAEW). The mid-intervention survey found that change was underway. The impact on weight status, behaviours and environments is presented.