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Deals with a study which utilized AuGe-Ni for the fabrication of ohmic contacts to n-gallium arsenide. Behavior of evaporated AuGe-Ni alloy; Redistribution of contituents in the ohmic contact formation; Details on furnace alloying.

Presents a study which examined the composition of porous silicon (PS). Background on PS; Elastic recoil detection spectrum for a PS specimen; Scanning electron micrograph of PS surface at high resolution using a field emission electron source.

Examines the compaction, distribution and chemical bonding of tungsten-implanted glassy carbon. Microstructure of glassy carbon; Effect of ion implantation on the resistance of glassy carbon; Rutherford backscattering spectrometry for various tungsten doses.

Air quality data collected at urban background locations is often assumed to represent a wider urban area. Localised sources and conditions can however cause variation between different microenvironments in the same urban area. Differences in PM25 (particulate less than 2.5 µm) composition may also have greater implications for health outcomes than PM2.5 concentration considered alone. Samples of PM2.5 were collected for three outdoor and nine indoor microenvironments across Suva, Fiji in 2014/15. Elemental concentration data have been used to estimate source contributions to PM2.5 for each site. The 12 sites are compared to concurrent ambient measurements at a fixed monitoring site in Suva City and to ambient photometer data. The objective is to determine how well ambient measurements represent air quality across the city, including indoor environments. Surveys were used to determine how much time is spent indoors and outdoors by Suva residents to ascertain potential exposure risks. Results show that PM2.5 concentration and composition varies significantly between the different microenvironments studied. Indoor air quality was affected by both ambient air and indoor sources. Fuel used for cooking, particularly wood and kerosene, influenced indoor PM2.5 and black carbon. Given that the survey showed that people spend more time indoors than outdoors, as experienced elsewhere in the world, ambient measures of PM2.5 concentration and calculated related health risk does not accurately reflect exposures arising from city indoor microenvironments. [ABSTRACT FROM AUTHOR]

Ambient particulate matter (APM) pollution, often generically referred to as smog or haze, is a global problem impacting every country and region in the world to varying degrees. Countries within the rapidly developing Asia-Pacific region have much higher levels of APM compared with many internationally recognised health goals. This paper presents two new aerosol databases compiled as the result of a long-term project spanning 15 years and involving 14 countries in the Asia-Pacific region under the auspices of the International Atomic Energy Agency (IAEA). The first database, named the Asia-Pacific Aerosol Database (APAD), contains the elemental concentration and associated error and minimum detectable limits (MDL) for 14,016 APM samples collected between 2002 and 2015. The second database, named the Asia-Pacific Source Fingerprint Database (ASFID), contains receptor source fingerprints and source apportionment solutions obtained by each country from their APAD dataset using positive matrix factorisation (PMF) methods. There is a wealth of untapped information contained in these databases that are constantly being utilised as part of this IAEA project. So it is particularly exciting that both the APAD and ASFID have been made publically available by all of participating countries through the IAEA. We anticipate that these databases will prove to be a valuable resource not only to pollution regulators but the wider aerosol and health researcher community in general for many years to come. [ABSTRACT FROM AUTHOR]

Trace element deposition from desert dust has important impacts on ocean primary productivity. In this study, emission inventories for 8 elements, which are primarily of soil origin, Mg, P, Ca, Mn, Fe, K, Al, and Si were determined based on a global mineral dataset and a soils dataset. Datasets of elemental fractions were used to drive the desert dust model in the Community Earth System Model (CESM) in order to simulate the elemental concentrations of atmospheric dust. Spatial variability of mineral dust elemental fractions was evident on a global scale, particularly for Ca. Simulations of global variations in the Ca / Al ratio, which typically ranged from around 0.1 to 5.0 in soil sources, were consistent with observations, suggesting this ratio to be a good signature for dust source regions. The simulated variable fractions of chemical elements are sufficiently different that estimates of deposition should include elemental variations, especially for Ca, Al and Fe. The model results have been evaluated with observational elemental aerosol concentration data from desert regions and dust events in non-dust regions, providing insights into uncertainties in the modeling approach. The ratios between modeled and observed elemental fractions ranged from 0.7 to 1.6 except for 3.4 and 3.5 for Mg and Mn, respectivly. Using the soil data base improved the correspondence of the spatial hetereogeneity in the modeling of several elements (Ca, Al and Fe) compared to observations. Total and soluble dust associated element fluxes into different ocean basins and ice sheets regions have been estimated, based on the model results. Annual inputs of soluble Mg, P, Ca, Mn, Fe and K associated with dust using mineral dataset were 0.28 Tg, 16.89 Gg, 1.32 Tg, 22.84 Gg, 0.068 Tg, and 0.15 Tg to global oceans and ice sheets. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine if month of birth affects performance in 3 tests of physical function in children and adolescents. We measured cardiorespiratory fitness, handgrip strength and lower-body power expressed them relative to (whole year) age then compared scores between calendar year birth-months. We also expressed test performance as the likelihood of achieving criterion-referenced fitness standards. There were significant main effects of birth-month for cardiorespiratory fitness (F = 4.54, p < 0.001), strength (F = 6.81, p < 0.001) and power (F = 3.67, p < 0.001). Children born in November were fitter and more powerful than those born at other times, particularly the summer months (April, May and June). October-born children were stronger than those born in all months except September and November. This relationship was evident despite controlling for decimal age and despite no significant inter-month differences in anthropometric characteristics. There is a clear physical advantage for those born in the autumn and this may explain some of the bias in sports selection attributed to the relative age effect, particularly when the British school-year (September) cut-off is used. [ABSTRACT FROM AUTHOR]

In September 2009, a major dust storm crossed eastern Australia, blanketing Sydney on two occasions. We collected size-resolved aerosol samples on both days, and also on the following days, for comparison. The size distribution during the dust storm showed a strong coarse mode, as expected. We subjected these samples to Ion Beam Analysis at ANSTO0 obtaining their size-resolved chemical composition. In this paper we present these results, and compare them with some of the analysis of similar samples obtained in field trips to the Lake Eyre Basin of central Australia, the source region for much of the dust. In particular, the Fe/AI ratios (-0.9) are similar to LEB values (-0.8- 1.0), and higher than northern hemisphere values (-0.55). Salt entrainment indicates a contribution from dry lakes. [ABSTRACT FROM AUTHOR]

Mineral dust is one of the major components of the world's aerosol mix, having a number of impacts within the Earth system. However, the climate forcing impact of mineral dust is currently poorly constrained, with even its sign uncertain. As Australian deserts are more reddish than those in the northern hemisphere, it is important to better understand the physical, chemical and optical properties of this important aerosol. We have investigated the properties of Australian desert dust at a site in SW Queensland, which is strongly influenced by both dust and biomass burning aerosol. Three years of ground-based monitoring of spectral optical thickness has provided a statistical picture of gross aerosol properties. In November 2006 we undertook a field campaign which collected 4 sets of size-resolved aerosol samples for laboratory analysis - both ion beam analysis and ion chromatography. The aerosol optical depth data showed a weak seasonal cycle with an annual mean of 0.06±0.03. The Angstrom coefficient showed a stronger cycle, indicating the influence of the winter-spring burning season in Australia's north. Size distribution inversions showed a bimodal character, with the coarse mode assumed to be mineral dust, and the fine mode a mixture of biomass burning and marine biogenic material. Ion Beam Analysis was used to determine the elemental composition of all filter samples, although elemental ratios were considered the most reliable output. Scatter plots showed that Fe, Al and Ti were well correlated with Si, and Co reasonably well correlated, with the Fe/Si ratio higher than the crustal average, as expected. Scatter plots for Ca, Mn and K against Si showed clear evidence of a second population, which in some cases could be identified with a particular sample day or size fraction. Ion Chromatography was used to quantify water soluble ions for 2 of our sample sets, showing the importance of marine influences on both fine (biogenic) and coarse (sea salt) modes. [ABSTRACT FROM AUTHOR]