نتایج جستجو برای: dust

تعداد نتایج: 41809  

Journal: :جغرافیا و توسعه ناحیه ای 0
اسماعیل نصیری حمزه احمدی طالب احمدی

1- introduction despite of technology progressives, natural hazards caused damage of world cities propertys and life, part of the damages related to adequate uncognition response to natural hazards. the dust natural hazard occurrence has attracted public attention in the recent years. nonrecieption and attention to the natural hazards not only affected society economic, but also affected differ...

Journal: :جغرافیا و مخاطرات محیطی 0
فهیمه محمدی سمیه کمالی مریم اسکندری

1. introduction dust phenomenon which occurs in arid and semiarid lands of the world is closely related to climatic characteristics of the region. according to the world meteorological organization (wmo), whenever wind speed exceeds 15 meter per second and horizontal visibility reduces to less than 1 km in a station, dust storm is reported (goudie & mideleton, 2006). great storms are created wh...

Journal: :desert 0
h. ahmadi professor, science and research branch, islamic azad university, tehran, iran m.a. saremi naeini msc graduate, university of teheran, karaj, iran m. yadegari retired engineer, abadan refinery, abadan, iran

in order to recognize the wind erosion situation of a region, the survey of its windiness is not sufficient and the physical characteristics of earth are of importance too. in fact, the outbreak of dust storms in a region is due to the sensitivity of earth and domination of wind in that region. in this investigation we have tried to find a way for determining the regions in which a dust storm i...

Background and Amis: The most important environmental challenges facing the West of iran in recent years is the dust phenomenon, that today has become one of the most important problems in arid and semi-arid areas. This phenomenon occurs as a climatic phenomenon in all climatic conditions, that causes adverse social, economic, environmental and commercial impacts. In this research have used dus...

Dust is one of the common processes of arid and semiarid regions that its occurrence frequencies has increased in recent years in Iran. The proper identification of sand and dust storms (SDS) is particular importance due to its impact on the environment and human health. So far, several methods for identifying these sources have been proposed such as methods based on field studies and geomorpho...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1997
R A Muller G J MacDonald

Spectral analysis of climate data shows a strong narrow peak with period approximately 100 kyr, attributed by the Milankovitch theory to changes in the eccentricity of the earth's orbit. The narrowness of the peak does suggest an astronomical origin; however the shape of the peak is incompatible with both linear and nonlinear models that attribute the cycle to eccentricity or (equivalently) to ...

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2013
David Williams Serena Viti

We discuss several types of regions in the interstellar medium of the Milky Way and other galaxies in which the chemistry appears to be influenced or dominated by surface and solid-state processes occurring on or in interstellar dust grains. For some of these processes, for example, the formation of H₂ molecules, detailed experimental and theoretical approaches have provided excellent fundament...

1998
JOHN M. HARKIN

Although many outlets are available for the utilization of wood fines, economical disposal of sawdust, shavings, and waste chips remains a problem of growing concern to the wood industry. This report summarizes current uses for wood residues and provides sources of further information on available outlets, processing methods, and economic considerations. USES FOR SAWDUST, SHAVINGS, AND WASTE CHIPS

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