28,649 research outputs found
Are Superhumps Good Measures of the Mass Ratio for AM CVn Systems?
We extend recent work that included the effect of pressure forces to derive
the precession rate of eccentric accretion discs in cataclysmic variables to
the case of double degenerate systems. We find that the logical scaling of the
pressure force in such systems results in predictions of unrealistically high
primary masses. Using the prototype AM CVn as a calibrator for the magnitude of
the effect, we find that there is no scaling that applies consistently to all
the systems in the class. We discuss the reasons for the lack of a superhump
period to mass ratio relationship analogous to that known for SU UMa systems
and suggest that this is because these secondaries do not have a single valued
mass-radius relationship. We highlight the unreliability of mass-ratios derived
by applying the SU UMa expression to the AM CVn binaries.Comment: 7 pages, 2 tables, to appear in Monthly Notices of the Royal
Astronomical Societ
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The Tagish Lake chondrite and the interstellar parent body hypothesis
Investigation of the solvent extractable organic compounds in Tagish Lake. The results are used to test the interstellar parent body hypthesis for the origin of extraterrestrial organic matter
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Simulating the Martian Chemical Enivronment
We report on new analogue materials to simulate Martian rocks and soils, especially under realistic redox conditions
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Organic indicators of alteration in the CR chondrites
A study of the organic components in the CR chondrite macromolecule in order to assess the role of pre-terrestrial alteration on the organic inventory
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Analysis of Tagish Lake macromolecular organic material
Macromolecular material is, by far, the major organic component of meteorites. Flash pyrolysis GCMS has been used to investigate this organic component in Tagish Lake. It is more condensed, less susbtituted than Murchson
Don’t get involved: an examination of how public sector organisations in England are involving disabled people in the Disability Equality Duty
The Disability Equality Duty (DED) came into force in December 2006. It stipulated that all public sector organisations were to develop policies to promote the equality of disabled people as staff members, consumers or visitors. Its emergence comes as part of a network of social policies developed over the last 20 years to promote disability rights and citizenship in the UK. However unlike previous legislation, the DED set in place the need for organisations to be pro-active in their policies and work with disabled people to move towards change in public sector cultures and working practices. This article reports on this early stage of implementation in England. Findings show that whilst some progress has been made in securing change, practice varied greatly. Therefore if a fundamental change in the culture of work and service provision is to be secured, this key requirement will need to be given a higher priority by organisations
Coal feed component testing for CDIF
Investigations conducted during the conceptual design of the Montana MHD Component Development and Integration Facility (CDIF) identified commercially available processing and feeding equipment potentially suitable for use in a reference design. Tests on sub-scale units of this equipment indicated that they would perform as intended
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The Physio-Chemical Properties for the Interior of Enceladus
We have reviewed the current physical and chemical conditions of the Enceladus sub-surface environment, including the composition, temperature, pH and pressure. Here we have defined some of these parameters and, through the aid of modelling, will define and refine the remaining parameters needed for our experimental work. Simulations of the chemical reactions occurring within Enceladus can then be carried
out to advance our understanding of the internal environment of Enceladus and help evaluate its potential habitability. Once a better understanding of the chemical reactions occurring at the rock-water interface has been carried out, then potential analogues on Earth can be evaluated and known microbial life can be tested to see if it could survive the conditions of Enceladus
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