نتایج جستجو برای: Particles and aerosols

تعداد نتایج: 16853764  

2010
L. Boudin A. Devys C. Grandmont B. Grec D. Yakoubi

In this work, we investigate two different aspects of an aerosol behaviour in the human airways. After a brief presentation of the model, we first study the impingement of aerosol particles with respect to their Stokes number and obtain again some well-known results. Then we consider the effect of an aerosol on the airflow and obtain a range of particles size where the aerosol action on the air...

Aerosols are tiny liquid or solid particles suspended in the air have a strong influence on air quality, human health and climate change. Sun-photometer is a tool for measuring the optical and physical characteristics of aerosols by using sunlight at various wavelengths from the Earth surface. In this paper, the design, construction, and calibration of a single channel sun-photometer is present...

Natural resources play a fundamental role in the economy of country and create the situation to achieve the goals of sustainable society, these valuable resources have to be conserved  and used with care. Destroying the forests and rangelands will lead to a dark future full of poverty, starvation and environmental pollution. Forests and rangelands play a considerable role in reducing air pollut...

Journal: :فیزیک زمین و فضا 0
امید غفارپسند استادیار، گروه فیزیک، دانشگاه اصفهان، ایران فهیمه حسینی بالام دانشیار، گروه فیزیک، دانشگاه اصفهان، ایران اسماعیل حسن زاده استاد، گروه فیزیک، دانشگاه اصفهان، ایران

in this study, the dispersion mechanisms of aerosols suspended in a turbulent plane channel flow is investigated using a novel numerical approach. a turbulent channel flow is simulated by a direct numerical simulation (dns) method, for which no-slip boundary conditions are assumed at the top and bottom walls, while periodicity conditions are applied on the other sides. dns, in particular, allow...

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه دانشهای بنیادی (مرکز تحقیقات فیزیک نظری و 1387

we show that when both sources ( lepton flavor violation sources and cp-violating phases) are present, the electric dipole moment of the electron, $d_e$, receives a contribution from the phase of the trilinear $a$-term of staus, $phi_{a_ au}$. for $phi_{a_ au}=pi/2$, the value of $d_e$, depending on the ratios of the lfv mass elements, can range between zero and three orders of magnitude a...

Bahram Abedi Ravan Mohsen Javaherian,

The Earth’s atmosphere is an environment replete with particles of differ-ent sizes with various refractive indices which affect the light radiation traveling through it. The Mie scattering theory is one of the well-known light scattering techniques ap-plicable to modeling of electromagnetic scattering from tiny atmospheric particles or aerosols floating in the air or within the clouds. In this...

Background: In recent years, Tehran has faced major problems with air pollution for many reasons, and this issue has become a critical point in most of the days. However, less attention has been paid to the indoor air pollutants in exercise centers and their possible health effects. In this research, it was tried to briefly describe the characteristics and chemical composition of the aerosols p...

2006
Yong-Le Pan Richard K. Chang

Environmental and occupational monitoring of hazardous aerosols, especially bioterrorism threats by way of dispersal of pathogenic bioaerosols, requires advanced systems that can identify harmful bioaerosol particles in quasi real-time and in situ. Instruments presently available to identify airborne biowarfare agents (BWA), mostly based on biochemical technologies, cannot be run continuously a...

2011
C. Pfrang M. Shiraiwa

Recent experimental evidence underlines the importance of reduced diffusivity in amorphous semi-solid or glassy atmospheric aerosols. This paper investigates the impact of diffusivity on the ageing of multi-component reactive organic particles approximating atmospheric cooking aerosols. We apply and extend the recently developed KMSUB model in a study of a 12-component mixture containing oleic ...

2013
Alexandra Antonnikova Natalya Korovina Olga Kudryashova

The article is devoted to a problem of sedimentation of superfine aerosols with a characteristic size of particles, an order of values of micrometers. Acceleration of the sedimentation process is promoted by imposing of an acoustic field that leads to acceleration of coagulation of particles. Besides, pressure of the sound radiation directed down, accelerates gravitational sedimentation of an a...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید