Storage diagenesis versus sulphide authigenesis: possible implications in environmental magnetism     

F. Oldfield  I. Darnley  G. Yates  D. E. France  J. Hilton 《Journal of Paleolimnology》1992,7(3):179-189

Experiments involving the gradual drying out of controlled mixtures of soil and organic lake sediment during storage at room temperature show that this leads to a loss of magnetic susceptibility and isothermal remanence greatly in excess of the initial values for the sediment components of the mixtures. We conclude that during storage in the moist state, soil-derived, fine-grained, ferrimagnetic iron oxides (magnetite and/or maghemite) are transformed to paramagnetic and/or imperfect antiferrimagnetic minerals. The imperfect anti-ferromagnetic component of the initial mixtures, which probably includes goethite, appears to survive and may even increase during storage. The experimental results compare well with the previously documented effects of storing wet sediment from the site, Peckforton Mere, Cheshire, U.K., over a comparable time interval. We conclude that transformation of fine grained ferrimagnets during storage diagenesis may be responsible for many of the examples of loss of magnetic susceptibility and remanence attributed by other authors solely to the oxidation of an iron sulphide such as greigite. Only where greigite is positively identified is it valid to infer a contribution from it to the magnetic properties of lake sediments: loss of susceptibility or remanence during storage is not alone a sufficient basis for such an inference. Early drying of samples will normally avoid the effects of storage diagenesis; and recent sediment samples so treated will, where greigite formation, bacterial magnetite and magnetite dissolution are insignificant, provide a valid basis for source identification on the basis of magnetic properties.  相似文献   

Multibeam maser survey of methanol and excited OH in the Magellanic Clouds: new detections and maser abundance estimates     

J. A. Green  J. L. Caswell  G. A. Fuller  S. L. Breen  K. Brooks  M. G. Burton  A. Chrysostomou  J. Cox  P. J. Diamond  S. P. Ellingsen  M. D. Gray  M. G. Hoare  M. R. W. Masheder  N. McClure-Griffiths  M. Pestalozzi  C. Phillips  L. Quinn  M. A. Thompson  M. Voronkov  A. Walsh  D. Ward-Thompson  D. Wong-McSweeney  J. A. Yates  R. J. Cohen † 《Monthly notices of the Royal Astronomical Society》2008,385(2):948-956

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The circumstellar envelope of S persei     

A. M. S. Richards  R. J. Cohen  J. A. Yates 《Astrophysics and Space Science》1995,224(1-2):545-546

We present MERLIN observations of OH and H₂O masers in the circumstellar envelope of S Per. The results are consistent with a model of a thick shell of H₂O masers in a region which is still accelerating.  相似文献   

Emerging transitions in organic waste infrastructure in Aotearoa New Zealand     

Gradon Diprose  Kelly Dombroski  Emma Sharp  Amanda Yates  Bailey Peryman  Martine Barnes 《New Zealand geographer》2023,79(1):15-26

Aotearoa New Zealand is at a critical juncture in reducing and managing organic waste. Research has highlighted the significant proportion of organic waste sent to landfills and associated adverse effects such as greenhouse gas emissions and loss of valuable organic matter. There is current debate about what practices and infrastructure to invest in to better manage and use organic waste. We highlight the diversity of existing organic waste practices and infrastructures, focusing on Auckland, Wellington and Christchurch. We show how debates about organic waste practices and infrastructure connect across three themes: waste subjectivities, collective action in place and language.  相似文献