Search

We have optimized the wet precipitation synthesis of hydroxyapaptite to obtain thermally stable powder in the short time span of 3 min. Exposure of the reaction mixture to 1000 W microwave for 3 min furnished hydroxyapatite, which was thermally stable at temperatures up to 1200 °C. Powders were analyzed for phase purity using X-ray crystallography; chemical composition was studied using Fourier transform infrared spectroscopy while particle morphology was analyzed using scanning electron microscopy. © 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Young people from refugee backgrounds face a number of challenges in adjusting to life in a new country. Recently, there have been more studies documenting some of these challenges and experiences, and offering recommendations for the health and education sector to appropriately respond to their needs. This study sought to investigate some of the experiences and challenges faced by female Afghan Hazara refugee adolescents as a precursor to program development occurring within a community health service in the outer southeastern suburbs of Melbourne, Australia. This paper reports on a cross-sectional participatory qualitative research study undertaken with young Afghan female adolescents aged 14–17 years of Hazara ethnicity. The results document some of the key contested gender and cultural challenges facing these young women, their aspirations for their lives in Australia, and how this research has informed community health practice.

We consider a (1+1) dimensional scalar field theory that supports oscillons, which are localized, oscillatory, stable solutions to nonlinear equations of motion. We study this theory in an expanding background and show that oscillons now lose energy, but at a rate that is exponentially small when the expansion rate is slow. We also show numerically that a universe that starts with (almost) thermal initial conditions will cool to a final state where a significant fraction of the energy of the universe -- on the order of 50% -- is stored in oscillons. If this phenomenon persists in realistic models, oscillons may have cosmological consequences., Comment: 13 pages, 4 .eps figures, uses RevTeX4; v2: clarified details of expansion, added references

Aluminum, the most common metallic element in the earth's crust, offers structural materials with high strength and light weight. It is widely used throughout the world economy, particularly in the transportation, packaging, and construction industries. Once extracted from ore, solidification is the most important phase transformation in the development of aluminum products, especially for critical applications. All of these applications rely on the ability of aluminum alloys to form a homogenous granular structure with a relatively small grain size, known as grain refinement. This thesis involves the use of in-situ experimental techniques like neutron scattering, synchrotron radiation, and differential thermal analysis to investigate the mechanism of nucleation and subsequent growth of individual grains during solidification. The aluminium alloys contained grain refiners like TiB2 particles along with solute titanium. The results indicate that the grain refiners have little influence on the overall short-range order in the liquid aluminum alloy prior to the solidification. Grain refinement is only effective when both solute titanium and TiB2 particles are present in the melt during solidification. The results shows that the TiB2 substrates stabilise a TiAl3 phase in a limited temperature range above the solidification temperature of aluminum. This observation pinpoints the highly debated mechanism that is responsible for enhanced grain nucleation during solidification of grain refined aluminum alloys. The results further demonstrate that the nucleation process is limited to the initial stage of the solidification and is complete at a solid phase fraction of about 20% for all the investigated aluminum alloys. The growth curves of the individual aluminum grains exhibit three different stages during solidification. The first stage of grain growth curve is consistent with the model prediction for diffusion-controlled growth of non-interacting grains. The later stages c, Applied Sciences