نتایج جستجو برای: dust

تعداد نتایج: 41809  

Journal: :جغرافیا و مخاطرات محیطی 0
محمدرضا محمدپور پنچاه محمدحسین معماریان سید مجید میررکنی

introduction one of the factors that affect the climate of arid and semi-arid areas is dust storm. numerical models are new methods for evaluation of dust storms which can also be used for forecasting dust storms. weather patterns that lead to dust outbreaks can be simulated using computer models that support a wide range of simulations related to the long-range transport, dispersion, and depos...

Journal: :فیزیک زمین و فضا 0
فرنوش عطایی موسسه ژئوفیزیک پرویز ایران نژاد هیئت علمی موسسه ژئوفیزیک مجید مزرعه فراهانی موسسه ژئوفیزیک امید علیزاده چوبری موسسه ژئوفیزیک

mineral dust is produced from both natural and anthropogenic sources. dust aerosols can be transported over long distances in the atmosphere. they reduce the incident shortwave radiation to the surface by absorbing and scattering the solar radiation; thereby leading to a cooling effect at the surface and lower tropospheric temperature. on the other hand, by absorption and re-emission of longwav...

ژورنال: علوم آب و خاک 2015
جعفری, فریبا, خادمی, حسین,

Dust deposition occurs extensively in arid and semiarid regions of the world. Since dust particles are fine-sized, they have a high adsorption capacity and also high contamination potential. The objective of this study was to evaluate the temporal and spatial distribution of the rate of atmospheric dust deposition in different locations in Kerman urban area. Dust samples were collected monthly ...

Dust is referred to sediments of less than 100 microns in size which are transmitted as suspended particles. Dust storms are events which naturally occur in arid and semi-arid areas, especially in subtropical latitudes. One of the most known sources of dust is the west of Asia, including Arabian Peninsula, Syria, Iraq, and Iran, especially Khuzestan Province. The purpose of this study is to inv...

B Farokhi, M Shahmansouri,

  Nonlinear Dust lattice modes are studied in a hexagonal two-dimensional dusty plasma lattice, in presence of charge gradient of dust particles. In this lattice, such gradients affect nonlinear behavior of dust lattice waves. The amplitude modulation of off-plane transverse dust lattice wave packets is investigated considering the anisotropy of interactions, caused by the height-dependent char...

Journal: :جغرافیا و مخاطرات محیطی 0
جمیله محمدی مرادیان سید رضا حسین زاده

1. introduction in recent years, desert dust frequency has increased in the global system. due to lack of vegetation in the regions prone to dust, the earth’s surface air becomes warm enough in these regions, moves upward and causes a cold downward circular air flow when it collides with upper tropospheric winds. when these winds strongly hit the earth’s surface, they create dust storms (xuan e...

Journal: :iranian journal of public health 0
h.dehghan shahreza n. razavizadeh

this research was conducted from july 1993 to june 1994 on the total population (711 workers) of a glass factory. the purpose of this study was to determine the quantitative free silica (quartz) in respiratory zone of workers in glass industry. field samples including 50 samples total dust and 37 samples respirable dust and standard simplex were collected on membrane filters using skc dust samp...

Journal: Desert 2012
H. Ahmadi M. Yadegari M.A. Saremi Naeini

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...

Detecting the spatial distribution of dust storms in the deposition regions is an essential step for managing this natural and human-induced crisis. This study aimed to investigate the performance of the Normalized Differences Dust Index (NDDI) applied to MODIS data (4/7/2009) for detection of dust storms in the Khuzestan Province. The extracted NDDI map was classified by value pixel in six cla...

Background & objective: Industrial ventilation systems and dust collectors are effective solutions to reduce particulate emissions in the workplace and environmental in mineral processes. In this study, Local Exhaust Ventilation System and dust collectors for control of emitted silica, coke, silicon carbide dusts from crushing unit was designed and evaluated. Methods: : Local Exhaust venti...

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