Analysis of the thermal stress behaviour of functionally graded hollow circular cylinders

This paper presents an analysis of the thermomechanical behavior of hollow circular cylinders of functionally graded material (FGM). The solutions are obtained by a novel limiting process that employs the solutions of homogeneous hollow circular cylinders, with no recourse to the basic theory or the equations of non-homogeneous thermoclasticity. Several numerical cases are studied, and conclusions are drawn regarding the general properties of thermal stresses in the FGM cylinder. We conclude that thermal stresses necessarily occur in the FGM cylinder, except in the trivial case of zero temperature. While heat resistance may be improved by sagaciously designing the material composition, careful attention must be paid to the fact that thermal stresses in the FGM cylinder are governed by more factors than are its homogeneous counterparts. The results that are presented here will serve as benchmarks for future related work. (C) 2003 Elsevier Science Ltd. All rights reserved.

40Ar/39Ar constraints on a temporal link between gold mineralization, magmatism, and continental margin transtension in the Jiaodong Gold Province, eastern China

The Jiaodong gold province is the largest gold repository in China. Both mineralization and granitoid hosts are spatially related to the crustal-scale Tan-Lu strike-slip fault system, which developed along the Mesozoic continental margin in eastern China. A series of Ar-40/Ar-39 laser incremental heating analyses of hydrothermal sericite/muscovite from three major gold deposits (Jiaojia, Xincheng, and Wangershan) and igneous biotite from the granodiorite hosts were performed to establish a possible temporal link between gold mineralization, magmatism, and movement along the Tan-Lu fault zone. Magmatic biotite crystals yield well-defined and concordant plateau ages between 124.5+/-0.4 Ma and 124.0+/-0.4 Ma (2sigma), whereas sericite and muscovite samples (a total of 30 single separates) give reproducible plateau ages ranging from 121.0+/-0.4 Ma to 119.2+/-0.2 Ma (2sigma). An integration of our Ar-40/Ar-39 results with age data from other major gold deposits in Jiaodong demonstrates that widespread gold mineralization occurred contemporaneously during a 2-3-m.yr. period. Most gold deposits show intimate spatial associations with abundant mafic to intermediate dikes. The mafic dikes have K-Ar ages of 123.5-119.6 Ma, in excellent agreement with those of the gold deposits. These newly obtained Ar-40/Ar-39 ages, in combination with other independent geological and geochronological data on granodioritic intrusions (130-126 Ma), volcanic rocks (1243.6-114.7 Ma), and deformed rocks within strike-slip faults (132-120 Ma) in Jiaodong or adjacent areas, also support the idea that gold mineralization postdated the granodioritic magmatism but was contemporaneous with mafic magmatism and volcanism, all controlled by the transtensional motion along the Tan-Lu fault in the Early Cretaceous.

Regional development rhrough domestic and tourist event policies: Gold Coast and Brisbane 1974-2003

Governments, as key stakeholders in the development of events, produce policies to facilitate the growth and potential of events as a platform for industry and economic development. To date, however, there has been a paucity of research undertaken to determine the appropriateness and the consequences of government policies pertaining to events. This paper studies the event policies of two Australian local government authorities, the Gold Coast City Council and Brisbane City Council, from 1974-2003, as measured by four development paradigms: Modernisation, Dependency, Economic Neoliberalism, and Alternative. The analysis revealed that these policies were predominantly underpinned by the Alternative which has a strong socio-cultural focus. Increased awareness and utilisation of the various development paradigms will assist local governments in producing future event policies to promote growth of the event industry and concomitantly, appropriate development within their region.

Type of housing predicts rate of readmission to hospital but not length of stay in people with schizophrenia on the Gold Coast in Queensland

Accommodation is considered to be important by institutions interested in mental health care both in Australia and internationally. Some authorities assert that no component of a community mental health system is more important than decent affordable housing. Unfortunately there has been little research in Australia into the consequences of discharging people with a primary diagnosis of schizophrenia to different types of accommodation. This paper uses archival data to investigate the outcomes for people with schizophrenia discharged to two types of accommodation. The types of accommodation chosen are the person's own home and for-profit boarding house. These two were chosen because the literature suggests that they are respectively the most and least desirable types of accommodation. Results suggest that people with schizophrenia who were discharged to boarding houses are significantly more likely to be readmitted to the psychiatric unit of Gold Coast Hospital although their length of stay in hospital is not significantly different. (author abstract)

The status of hollow-bearing trees required for the conservation of arboreal marsupials in the dry sclerophyll forests of south-east Queensland, Australia

At 38 sites in the dry sclerophyll forests of south-east Queensland, Australia, hollow-bearing trees were studied to determine the effects of past forestry practices on their density, size and spatial distribution. The density of hollow-bearing trees was reduced at sites that had been altered by poisoning and ringbarking of unmerchantable trees. This was especially the case for living hollow-bearing trees that were now at densities too low to support the full range of arboreal marsupials. Although there are presently enough hollow-bearing stags (i.e., dead hollow-bearing trees) to provide additional denning and nesting opportunities, the standing life of these hollow-bearing stags is lower than the living counterparts which means denning and nesting sites may be limited in the near future. The mean diameter at breast height (DBH) of hollow-bearing stags was significantly less than that of living hollow-bearing trees. This indicated that many large hollow-bearing stags may have a shorter standing life than smaller hollow-bearing stags. Hollow-bearing trees appear to be randomly distributed throughout the forest in both silviculturally treated and untreated areas. This finding is at odds with the suggestion by some forest managers that hollow-bearing trees should have a clumped distribution in dry sclerophyll forests of south-east Queensland.

Why H Atom Prefers the On-Top Site and Alkali Metals Favor the Middle Hollow Site on the Basal Plane of Graphite

In this work, the different adsorption properties of H and alkali metal atoms on the basal plane of graphite are studied and compared using a density functional method on the same model chemistry level. The results show that H prefers the on-top site while alkali metals favor the middle hollow site of graphite basal plane due to the unique electronic structures of H, alkali metals, and graphite. H has a higher electronegativity than carbon, preferring to form a covalent bond with C atoms, whereas alkaline metals have lower electronegativity, tending to adsorb on the highest electrostatic potential sites. During adsorption, there are more charges transferred from alkali metal to graphite than from H to graphite.

40Ar/39Ar geochronology of gold mineralization in Brasiliano strike-slip shear zones in the Barborema province, NE Brazil

40Ar/39Ar geochronology of muscovite and biotite grains genetically related to gold and Be–Ta–Li pegmatites from the Seridó Belt (Borborema province, NE Brazil) yield well-defined, reliable plateau ages. This information, combined with data about paragenetic and field relationships, reveals Cambro-Ordovician mineralization ages (520 and 500–506 Ma) for the orogenic gold deposits in the Seridó Belt. Biotite ages of 525±2 Ma, which represent the mean weighted results of the incremental heating analysis of six biotite single crystals, record the time of pegmatite emplacement and reactivation of Brasiliano/Pan-African strike-slip shear zones. These results, along with previous structural evolution studies, suggest that shear zones formed during the Brasiliano/Pan-African event were reactivated in the Upper Cambrian–Lower Ordovician. Mineralization occurs late in the history of the orogen.