منابع مشابه
Down with road dust.
Background: Despite the growth of biomedical research in South Africa, there are few insights into the operation of Research Ethics Committees (RECs) in this setting. We investigated the composition, operations and training needs of health RECs in South Africa against the backdrop of national and international guidelines. Methods: The 12 major health RECs in South Africa were surveyed using sem...
متن کاملDust Bowl 3 Drought and dust storms
A farmer and his two sons during a dust storm in Cimarron County, Oklahoma, 1936, Photo: Arthur Rothstein The Dust Bowl, or the Dirty Thirties, was a period of severe dust storms causing major ecological and agricultural damage to American and Canadian prairie lands in the 1930s, particularly in 1934 and 1936. The phenomenon was caused by severe drought coupled with decades of extensive farming...
متن کاملDust to Dust : Evidence for Planet Formation ?
We discuss the properties of several circumstellar debris disk systems imaged with the Hubble Space Telescope’s Near Infrared Camera and Multi-Object Spectrometer in a survey of young stars with known far-IR excesses. These dusty disks around young (∼ 5–8 Myr) unembedded stars exhibit morphological anisotropies and other characteristics which are suggestive of recent or on-going planet formatio...
متن کاملearly study of surfactants in indoor dust and their connection with street dust
as surfactants enhance the membrane transport of organic compounds, it has to be assumed that they decisively influence the absorption of pollutants from house dust. sampling sites for the surfactant analysis include housing areas, each location of which has different surroundings such as rural, urban, construction, and industrial area. three stations had been selected for each housing area and...
متن کاملOn -coalescents with Dust Component
We consider the -coalescent processes with a positive frequency of singleton clusters. The class in focus covers, for instance, the beta(a, b)-coalescents with a > 1. We show that some large-sample properties of these processes can be derived by coupling the coalescent with an increasing Lévy process (subordinator), and by exploiting parallels with the theory of regenerative composition structu...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1914
ISSN: 0036-8733
DOI: 10.1038/scientificamerican04041914-290