Artificial meteor ablation studies: Olivine

Artificial meteor ablation was performed on a Mg-rich olivine sample using an arc-heated plasma of ionized air. Experimental conditions simulated a meteor traveling about 12 km/sec at an altitude of 70 km. The mineral content of the original olivine sample was 98% olivine (including traces of olivine alteration products) and 2% chromite. Forsterite content of the original olivine was Fo-89. After ablation, the forsterite content had increased to Fo-94 in the recrystallized olivine. In addition, lamella-like intergrowths of magnetite were prevalent constituents. Wherever magnetite occurred, there was an increase in Mg and a corresponding decrease in Fe for the recrystallized olivine. The Allende fusion crust consisted of a recrystallized olivine, which was more Mg-rich and Fe-deficient than the original meteorite's olivine, and abundant magnetite grains. Although troilite and pentlandite were the common opaque mineral constituents in this meteorite, magnetite was the principal opaque mineral found in the fusion crust

Detection of SiO emission from a massive dense cold core

We report the detection of the SiO (J = 2 - 1) transition from the massive cold dense core G333.125-0.562. The core remains undetected at wavelengths shorter than 70 micron and has compact 1.2 mm dust continuum. The SiO emission is localised to the core. The observations are part of a continuing multi-molecular line survey of the giant molecular cloud G333. Other detected molecules in the core include 13CO, C18O, CS, HCO+, HCN, HNC, CH3OH, N2H+, SO, HC3N, NH3, and some of their isotopes. In addition, from NH3 (1,1) and (2,2) inversion lines, we obtain a temperature of 13 K. From fitting to the spectral energy distribution we obtain a colour temperature of 18 K and a gas mass of 2 x 10^3 solar mass. We have also detected a 22 GHz water maser in the core, together with methanol maser emission, suggesting the core will host massive star formation. We hypothesise that the SiO emission arises from shocks associated with an outflow in the cold core.Comment: 6 pages, 4 figures, 1 table, to be published in MNRA

The structure of 110 tilt boundaries in large area solar silicon

The models of Hornstra and their connection to the repeating group description of grain boundaries (7-10) are discussed. A model for the Sigma = 27 boundary containing a zig-zag arrangement of dislocations is constructed and it is shown that zig-zag models can account for the contrast features observed in high resolution transmission electron micrographs of second and third order twin boundaries in silicon. The boundaries discussed are symmetric with a 110 tilt axis and a (110) boundary plane in the median lattice (the median plane). The median lattice is identical in structure and halfway in orientation between the crystal lattices either side of the boundary

ACCOUNTING FOR SUSTAINABILITY: WHAT NEXT? A RESEARCH AGENDA

This working paper responds to increasing calls for more and different forms of accounting research involvement in accounting for sustainability. It seeks to provide background, clarify the accounting research issues, and suggest research methods. The background analysis indicates that accounting for sustainability must go beyond supplemental reporting of ecological and social information to include such emerging issues as integrated reporting of sustainability information along with financial reporting. Additional emerging issues are needs of users of sustainability reports, auditing and other assurance of sustainability information, and sustainability implications of financial failure, accounting and auditing failures, and lack of enforcement. Analysis of integrated reporting against traditional financial accounting theory concepts of the purpose of financial reporting and the postulates of going concern, reporting entity, monetary unit, and time period, indicates a need for substantial changes in the traditional financial accounting model if sustainability issues are to be integrated. The agenda concludes with five research issues and methods: - An accounting research framework for sustainability using general systems theory approaches that have been useful for similar emerging issues. - Reporting of sustainability information which has been the focus of most research to date, and the emerging important topic of integrated reporting. - Users of sustainable information, their uses and perceived needs, an area that has been largely neglected in research to date.- Auditing and assurance issues that are taking on greater importance as more users demand assurance for sustainability information. Issues include standards to be used and users expectations and reactions. - Financial distress and sustainability consequences of accounting and enforcement failures that are just now being recognized as sustainability issues.accounting for sustainability, integrated reporting, needs of users, audit, assurance

THE IMPACT OF IFRS ON REPORTING FOR BUSINESS COMBINATIONS: AN IN-DEPTH ANALYSIS USING THE TELECOMMUNICATIONS INDUSTRY

The mandatory use of IFRS by all publicly listed companies in the European Union created challenges for accounting and reporting of business combinations, goodwill impairment and disclosures for these items. Major issues are allocation of amounts to goodwill and specific intangible assets arising from acquisition. This study presents an in-depth exploration of compliance with IFRS 3 and IAS 36 using content analysis methodology of annual reports of eight European telecommunications that were chose because the industry is well known for significant acquisitions involving intangibles. The results show only partial compliance with little change over the four year period since mandatory IFRS adoption. While results cannot be generalized outside this group, the in-depth analysis yielded important insights for continued research using broader research methods.IFRS, business combinations, goodwill, content analysis, annual reports, listed companies

Assessing housing quality and its impact on health, safety and sustainability

Background The adverse health and environmental effects of poor housing quality are well established. A central requirement for evidence-based policies and programmes to improve housing standards is a valid, reliable and practical way of measuring housing quality that is supported by policy agencies, the housing sector, researchers and the public. Methods This paper provides guidance on the development of housing quality-assessment tools that link practical measures of housing conditions to their effects on health, safety and sustainability, with particular reference to tools developed in New Zealand and England. Results The authors describe how information on housing quality can support individuals, agencies and the private sector to make worthwhile improvements to the health, safety and sustainability of housing. The information gathered and the resultant tools developed should be guided by the multiple purposes and end users of this information. Other important issues outlined include deciding on the scope, detailed content, practical administration issues and how the information will be analysed and summarised for its intended end users. There are likely to be considerable benefits from increased international collaboration and standardisation of approaches to measuring housing hazards. At the same time, these assessment approaches need to consider local factors such as climate, geography, culture, predominating building practices, important housing-related health issues and existing building codes. Conclusions An effective housing quality-assessment tool has a central role in supporting improvements to housing. The issues discussed in this paper are designed to motivate and assist the development of such tools

A method for predicting full scale buffet response with rigid wind tunnel model fluctuating pressure data. Volume 1: Prediction method development and assessment

The method requires unsteady aerodynamic forces, natural airplane modes, and the measured pressure data as input. A gust response computer program is used to calculate buffet response due to the forcing function posed by the measured pressure data. By calculating both symmetric and antisymmetric solutions, upper and lower bounds on full-scale buffet response are formed. Comparisons of predictions with flight test results are made and the effects of horizontal tail loads and static aeroelasticity are shown. Discussions are also presented on the effects of primary wing torsion modes, chordwise and spanwise phase angles, and altitude

Receptor-Induced Thiolate Couples Env Activation to Retrovirus Fusion and Infection

According to current models of retrovirus infection, receptor binding to the surface subunit (SU) of the envelope glycoprotein (Env) triggers a conformational change in the transmembrane subunit (TM) that mediates virus fusion to cell membranes. To understand how this occurs, we investigated the role of the receptor Tva in avian leukosis virus-A (ALV-A) infection. We find that Tva binding induced the formation of a reactive thiolate on Cys38 (Cys38-S−) in SU. Both chemical and genetic inactivation of Cys38-S− completely abrogated ALV fusion and infection. Remarkably, Cys38-S− does not mediate isomerization of the SU-TM disulfide bond and is not required for Tva-induced activation of TM, including pre-hairpin association with membranes and low pH assembly of helical bundles. These findings indicate that, contrary to current models, receptor activation of TM is not sufficient for ALV fusion and infection and that formation of a reactive thiolate is an additional receptor-dependent step