نتایج جستجو برای: dust
تعداد نتایج: 41809 فیلتر نتایج به سال:
Rock dusting to prevent coal dust explosions has been in widespread use in U.S. underground coal mines since the early 1900s. Underground coal mining technology has changed significantly over this same time period, becoming highly mechanized and produces finer coal dust particles which are more explosive. Despite the advances in mining technology, mine-wide dust sampling practices have remained...
Interactions of desert dust and air pollution over the eastern Mediterranean (EM) have been studied, focusing on two distinct dust transport events on 22 and 28 September 2011. The atmospheric chemistry–climate model EMAC has been used at about 50 km grid spacing, applying an online dust emission scheme and calcium as a proxy for dust reactivity. EMAC includes a detailed tropospheric chemistry ...
Propagation of dust ion acoustic waves in plasmas composed of nonthermal distributed electrons and stationary dust particles is investigated. Nonlinear Schrdinger equation is derived to describe small amplitude waves, using the reduction perturbation technique. Modulation instability of dust ion acoustic waves is analysed for this system. Parametric investigation indicates that growth rate of...
Extended abstract 1- Introduction A dust storm is one of the biggest serious environmental problems in the arid and semi-arid regions of the world, causing irreparable damages to farms, facilities, roads, traffic and transportation every year and respitory problems by contaminating the air. Due to the geographic location of Iran which is in the arid and semi-arid belt of the world, the count...
We present regional model simulations of the dust emission events during the Bodélé Dust Experiment (BoDEx) that was carried out in February and March 2005 in Chad. A box model version of the dust emission model is used to test different input parameters for the emission model, and to compare the dust emissions computed with observed wind speeds to those calculated with wind speeds from the reg...
The purpose of this study was to model the relationship between the frequency of dust storms and climatic variables in desert areas of Iran. For this purpose, climatic data of temperature (maximum and minimum), rainfall, wind speed (maximum and minimum), and their relationship with the number of days with dust recorded in 25 meteorological stations (statistical period since their inception unti...
this study was carried out to evaluate tobacco dust concentration and also designing a suitable ventilation system for reduction of tobacco dust concentration in a tobacco processing factory in the north of iran.gravimetric method was used to determine the tobacco dust concentrations in the emission sources an also indoor workplace. a local exhaust ventilation system was designed according to t...
This study examined the potential for coal mine roof bolter dust to be a source of a worker’s exposure to respirable quartz. For the models of roof bolter studied, the dust from bolt hole drilling is collected by a dry vacuum exhaust system. The collected dust-laden air passes through a cyclone size-separator (pre-cleaner) and into a collector box containing two additional cyclones and a filter...
Background and Purpose: Inhalation of hardwood dust may produce a range of adverse health effects in the upper and lower respiratory system, including asthma, along with Sino-nasal cancer and nasopharyngeal cancer. This study was carried out to evaluate personal exposure to wood dust among workers in chipboard and furniture production saloons in Neka Choob factory, Iran. Materials a...
Due to the drought and land use changes in recent years, the phenomenon of storm dust in Iran is increasing as a dangerous environment. Dust influences climate change and human health, causing serious damage. The subject of this research is to identify and prepare a map of sensitivity of dust source area for controlling and determining the role of each of the factors affecting its occurrence us...
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