نتایج جستجو برای: ultrafine

تعداد نتایج: 4276  

2011
Wouter D. van Dijk Simone Gopal Paul T. J. Scheepers

Cigarette smoke is a complex mixture of smoke constituents, often characterised by size-resolved particle distributions. Since descriptions of ultrafine particles <50 nm are absent, our aim was to explore the existence of these nanoparticles in fresh and undiluted cigarette smoke. We measured undiluted smoke particles real-time by a scanning mobility particle sizer with Faraday cup electrometer...

Journal: :Environmental Health Perspectives 2003
Kevin R Smith Seongheon Kim Julian J Recendez Stephen V Teague Margaret G Ménache David E Grubbs Constantinos Sioutas Kent E Pinkerton

Epidemiologic studies have shown that airborne particulate matter (PM) with a mass median aerodynamic diameter < 10 microm (PM10) is associated with an increase in respiratory-related disease. However, there is a growing consensus that particles < 2.5 microm (PM2.5), including many in the ultrafine (< 0.1 microm) size range, may elicit greater adverse effects. PM is a complex mixture of organic...

2013
Jackie K. W. Chan Christoph F. Vogel Jaeeun Baek Sean D. Kodani Ravi S. Uppal Keith J. Bein Donald S. Anderson Laura S. Van Winkle

249/250 words) 41 Vehicle exhaust is rich in polycyclic aromatic hydrocarbons (PAH) and can be a dominant 42 contributor to ultrafine urban particulate matter (PM). Exposure to ultrafine PM is correlated with 43 respiratory infections and asthmatic symptoms in young children. The lung undergoes 44 substantial growth, alveolarization and cellular maturation within the first years of life, which ...

2003
N. Bukowiecki

On occasion of the project YOGAM (year of gas phase and aerosol measurements), the spatial and temporal variation of selected aerosol and gas phase parameters was assessed for the Zürich (Switzerland) area with a new mobile pollutant measurement laboratory. This assessment based on on-road measurements along a specified route on selected days during different seasons in 2001/2002, covering urba...

2006
P. Vaattovaara P. E. Huttunen A. Laaksonen

Newly-formed nanometer-sized particles have been observed at coastal and marine environments world wide. Organic species have so far not been detected in those newly-formed nucleation mode particles. In this study, we applied the ultrafine organic tandem differential mobility analyzer method to study the possible existence of an organic fraction in recently formed coastal nucleation mode partic...

2016
R. Pippan A. Hohenwarter

The suitability of high-strength ultrafine and nanocrystalline materials processed by severe plastic deformation methods and aimed to be used for structural applications will strongly depend on their resistance against crack growth. In this contribution some general available findings on the damage tolerance of this material class will be summarized. Particularly, the occurrence of a pronounced...

Journal: :Mutation research 2013
Jan Topinka Alena Milcova Jana Schmuczerova Jiri Krouzek Jan Hovorka

Some studies suggest that genotoxic effects of combustion-related aerosols are induced by carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) and their derivatives, which are part of the organic fraction of the particulate matter (PM) in ambient air. The proportion of the organic fraction in PM is known to vary with particle size. The ultrafine fraction is hypothesized to be the most importa...

Journal: :Environmental Health Perspectives 2001
P Penttinen K L Timonen P Tiittanen A Mirme J Ruuskanen J Pekkanen

Daily variations in ambient particulate air pollution are associated with variations in respiratory lung function. It has been suggested that the effects of particulate matter may be due to particles in the ultrafine (0.01-0.1 microm) size range. Because previous studies on ultrafine particles only used self-monitored peak expiratory flow rate (PEFR), we assessed the associations between partic...

2017
Shelly L. Miller Nick A. Facciola Darin Toohey John Zhai

The objectives of this study were to measure levels of particulate matter (PM) in mechanically ventilated buildings and to improve understanding of filtration requirements to reduce exposure. With the use of an Ultra High Sensitivity Aerosol Spectrometer and an Aerodyne Mass Spectrometer, ultrafine (0.055-0.1 μm) and fine (0.1-0.7 μm) indoor and outdoor PM was measured as a function of time in ...

Journal: :Journal of occupational and environmental hygiene 2009
William A Heitbrink Douglas E Evans Bon Ki Ku Andrew D Maynard Thomas J Slavin Thomas M Peters

This study investigated the relationships between particle number, surface area, and respirable mass concentration measured simultaneously in a foundry and an automotive engine machining and assembly center. Aerosol concentrations were measured throughout each plant with a condensation particle counter for number concentration, a diffusion charger for active surface area concentration, and an o...

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