نتایج جستجو برای: highly reactive vocs

تعداد نتایج: 638601  

2009
Kelly S. Ramirez Christian L. Lauber Noah Fierer K. S. Ramirez C. L. Lauber N. Fierer

Substantial amounts of volatile organic compounds (VOCs) can be released during decomposition and these compounds can affect atmospheric chemistry, belowground processes, and the structure of microbial communities in litter and soil. However, we have a limited understanding of the types, quantities and ecological impacts of VOCs emitted from litter. Here we used a closed flow-through system and...

2006
J. Zhang T. Wang W. L. Chameides C. Cardelino J. Kwok D. R. Blake A. Ding

Data obtained in Hong Kong during the Hong Kong and the Pearl River Delta (PRD) Pilot Air Monitoring Study in autumn 2002 are analyzed to unravel the relationship between ground-level ozone (O3), pollution precursors, and cross-border transport. Ten ozone episodes, during which the hourly O3 concentration exceeded 100 ppbv in 9 cases and 90 ppbv in one case, are subject to detailed analysis, in...

2006
S. Bartenbach

During a field campaign at the Meteorological Observatory Hohenpeissenberg (MOHp) in July 2004, volatile organic compounds (VOCs) were measured using comprehensive two-dimensional gas chromatography (GC×GC). Comparison to routinely made gas chromatography mass spectrometry (GC-MS) measurements showed good agreement for a variety of anthropogenic and biogenic ambient VOCs ranging in concentratio...

2004
K. Toyota Y. Kanaya M. Takahashi H. Akimoto

A new chemical scheme is developed for the multiphase photochemical box model SEAMAC (sizeSEgregated Aerosol model for Marine Air Chemistry) to investigate photochemical interactions between volatile organic compounds (VOCs) and reactive halogen species in the marine boundary layer (MBL). Based primarily on critically evaluated kinetic and photochemical rate parameters as well as a protocol for...

2007
T. G. Karl T. J. Christian R. J. Yokelson P. Artaxo W. M. Hao

Volatile Organic Compound (VOC) emissions from fires in tropical forest fuels were quantified using Proton-Transfer-Reaction Mass Spectrometry (PTRMS), Fourier Transform Infrared Spectroscopy (FTIR) and gas chromatography (GC) coupled to PTRMS (GC-PTR-MS). We investigated VOC emissions from 19 controlled laboratory fires at the USFS (United States Forest Service) Fire Sciences Laboratory and 16...

2006
Rainer Volkamer Jose L. Jimenez Federico San Martini Katja Dzepina Qi Zhang Dara Salcedo Luisa T. Molina Douglas R. Worsnop Mario J. Molina

[1] The atmospheric chemistry of volatile organic compounds (VOCs) in urban areas results in the formation of ‘photochemical smog’, including secondary organic aerosol (SOA). State-of-the-art SOA models parameterize the results of simulation chamber experiments that bracket the conditions found in the polluted urban atmosphere. Here we show that in the real urban atmosphere reactive anthropogen...

2016
Masanari KANEMITSU Yukiko FUETA Toru ISHIDAO Shuji AOU Hajime HORI

Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a cons...

Journal: :Journal of contaminant hydrology 2011
Daniel Bouchard Fabien Cornaton Patrick Höhener Daniel Hunkeler

Analytical models were developed that simulate stable isotope ratios of volatile organic compounds (VOCs) near a point source contamination in the unsaturated zone. The models describe diffusive transport of VOCs, biodegradation and source ageing. The mass transport is governed by Fick's law for diffusion. The equation for reactive transport of VOCs in the soil gas phase was solved for differen...

Journal: :Journal of breath research 2012
J King K Unterkofler G Teschl S Teschl P Mochalski H Koç H Hinterhuber A Amann

Isothermal rebreathing has been proposed as an experimental technique for estimating the alveolar levels of hydrophilic volatile organic compounds (VOCs) in exhaled breath. Using the prototypic test compounds acetone and methanol, we demonstrate that the end-tidal breath profiles of such substances during isothermal rebreathing show a characteristic increase that contradicts the conventional pu...

2017
Hao Zhang Qingzhu Zhang Yujie Zhang Weiqi Zhang Xuezhong Wang Fahe Chai Jian Gao Ting Yang Yizhen Chen Qi Cheng Kimitaka Kawamura

Atmospheric volatile organic compounds (VOCs) measurement was carried out using gas chromatography-flame ionization detector (GC-FID) technique (Airmo VOCs online analyzer) in a typical urban area in Beijing from April 2014 to January 2015. Ambient levels, variation characteristics and influential factors contributing to the formation of near-ground-ozone and secondary organic aerosols as well ...

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