نتایج جستجو برای: dust accumulation

تعداد نتایج: 190742  

Journal: :Indoor air 2002
R Holopainen M Tuomainen V Asikainen P Pasanen J Säteri O Seppänen

The aim of this study was to evaluate the amount of dust in supply air ducts in recently installed ventilation systems. The samples for the determination of dust accumulation were collected from supply air ducts in 18 new buildings that have been constructed according to two different cleanliness control levels classified as category P1 (low oil residues and protected against contaminations) an...

2016
Yu Jiang

This paper reports an experimental investigation of the dust particle deposition process on solar photovoltaic (PV) modules with different surface temperatures by a heating plate to illustrate the effect of the temperature difference (thermophoresis) between the module surface and the surrounding air on the dust accumulation process under different operating temperatures. In general, if the tem...

Bakand, Shahnaz, Ghazi Khansari, MMahmood, Koohi, Mohammad Kazem, Menhaje-Bena, Rabee, Modabberi, Soroush,

Introduction: Particulate matter (PM) is known as the most common cause of air pollution in the world. Activities of sand quarries are known as one of the emission sources in Tehran. This study aimed at investigating the geological and environmental factors of airborne particles in an active quarry in the west of Tehran. Material and Methods: Three methods of dust sampling were used. totally, ...

Heavy metal pollutionis one of the largest problems in the Environment and human being. In industrial and urban areas trees can give better quantifications for pollutant concentrations and atmospheric deposition than non-biological samples. In order to know ability of Fraxinus excelsior­ (Ash tree) to reduce the concentrations of heavy metals and compared with the concentration of thes...

ژورنال: علوم آب و خاک 2020

Dusts contain heavy metals such as Pb, Zn, Cu, Cr, Cd and As that can threat humanchr('39')s health and environment. Therefore, the spatial distribution of heavy metals concentration and soil pollution monitoring and environmental quality protection seem to be essential. To assess heavy metals pollution level in Ahvaz street dust, 115 street dust samples were collected from main pedestrians. Th...

Journal: Desert 2020
H. Sodaiezadeh M. Esfandiari, M.A. Hakimzadeh Ardakani

Dust storm is one of the criteria for air pollution, and pollution by Heavy Metal(HM) is one of the major environmental problems in the world. The objective of the present study was to assess some of HMs concentrations in the leaves and bark of cypress and atmospheric falling dust along the Yazd highway, Yazd Province, Iran. The total concentrations of cadmium (Cd), cobalt (Co), copper (Cu), ni...

2015
N. M. Mahowald G. Winckler R. F. Anderson L. I. Bradtmiller B. Delmonte R. François S. Albani M. Goman N. G. Heavens P. P. Hesse S. A. Hovan S. G. Kang K. E. Kohfeld H. Lu V. Maggi J. A. Mason P. A. Mayewski D. McGee X. Miao B. L. Otto-Bliesner A. T. Perry A. Pourmand H. M. Roberts J. Sun

Mineral dust plays an important role in the climate system by interacting with radiation, clouds, and biogeochemical cycles. In addition, natural archives show that the dust cycle experienced variability in the past in response to global and local climate change. The compilation of the DIRTMAP (Dust Indicators and Records from Terrestrial and MArine Palaeoenvironments) paleodust data sets in th...

2008
Taku Takeuchi Oliver Krauss

We study dust accumulation by photophoresis in optically thin gas disks. Using formulae of the photophoretic force that are applicable for the free molecular regime and for the slip-flow regime, we calculate dust accumulation distances as a function of the particle size. It is found that photophoresis pushes particles (smaller than 10 cm) outward. For a Sun-like star, these particles are transp...

2016
Brahim Aïssa Rima J. Isaifan Vinod E. Madhavan Amir A. Abdallah

Recently, extensive R&D has been conducted, both by industry and academia, to significantly raise the conversion efficiency of commercial photovoltaic (PV) modules. The installation of PV systems aimed at optimizing solar energy yield is primarily dictated by its geographic location and installation design to maximize solar exposure. However, even when these characteristics have been addressed ...

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