نتایج جستجو برای: hcfc

تعداد نتایج: 174  

2003

The use of the new HCFC solvents involves some design changes for equipment. These changes will achieve emission rates with HCFC solvents similar to those experienced with the present CFC solvents. New equipment designs are now available for HCFC solvents from several manufacturers. Modifications to existing equipment to allow HCFC solvent use have also proved feasible in many cases and offer a...

Journal: :Environmental science & technology 2007
Charlotte Scheutz Yutaka Dote Anders M Fredenslund Hans Mosbaek Peter Kjeldsen

Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs) have been used as blowing agents (BAs) for foam insulation in home appliances and building materials, which after the end of their useful life are disposed of in landfills. The objective of this project was to evaluate the potential for degradation of BAs in landfills, and to develop a landfill model, wh...

Journal: :Chemosphere 2005
Christian Balsiger Christof Holliger Patrick Höhener

The reductive transformation of the 10 most-widely distributed fluorinated volatile compounds and of tetrachloroethene was investigated for up to 177 days under anaerobic conditions in sewage sludge and aquifer sediment slurries. Concentrations of parent compounds and of degradation products were identified by GC-MS. We observed transformation of CFC-11 to HCFC-21 and HCFC-31, of CFC-113 to HCF...

2013
Barbara Barletta Marc Carreras-Sospedra Alex Cohan Paul Nissenson Donald Dabdub Simone Meinardi Elliot Atlas Rich Lueb John S. Holloway Thomas B. Ryerson James Pederson Richard A. VanCuren Donald R. Blake

[1] The CalNex 2010 (California Research at the Nexus of Air Quality and Climate Change) study was designed to evaluate the chemical composition of air masses over key source regions in California. During May to June 2010, air samples were collected on board a National Oceanic and Atmospheric Administration (NOAA) WP-3D aircraft over the South Coast Air Basin of California (SoCAB) and the Centr...

2004
D. P. Moore J. J. Remedios

Our retrievals of HCFC-22 vertical profiles volume mixing ratios (vmrs) from MIPAS-E spectral data are presented. Using a retrieval scheme developed at the University of Leicester we have detected a mean global enhancement of HCFC-22 vmrs compared to 1998 values. Latitudinal variations of HCFC-22 concentrations are also detected. A preliminary validation of our HCFC-22 retrievals is presented w...

Journal: :Environmental Health Perspectives 1991
M W Anders

Hydrochlorofluorocarbons (HCFCs) are being developed as replacements for chlorofluorocarbons (CFCs) that deplete stratospheric ozone. The depletion of stratospheric ozone may increase the intensity of ultraviolet radiation at the earth's surface, which may be associated with global, adverse human health effects. The greater tropospheric lability of HCFCs, which is due to the presence of C-H bon...

2012
E. Saikawa John M. Reilly

HCFC-22 (CHClF2, chlorodifluoromethane) is an ozone-depleting substance (ODS) as well as a significant greenhouse gas (GHG). HCFC-22 has been used widely as a refrigerant fluid in cooling and air-conditioning equipment since the 1960s, and it has also served as a traditional substitute for some chlorofluorocarbons (CFCs) controlled under the Montreal Protocol. A low frequency record on troposph...

Journal: :Environmental Health Perspectives 1996
W Dekant

Chlorofluorocarbons (CFCs) are stable in the atmosphere and may reach the stratosphere. They are cleaved by UV-radiation in the stratosphere to yield chlorine radicals, which are thought to interfere with the catalytic cycle of ozone formation and destruction and deplete stratospheric ozone concentrations. Due to potential adverse health effects of ozone depletion, chlorofluorocarbon replacemen...

2018
Mu Young Shin Jong Soo Park Hae Dong Park Jihye Lee

Background Exposure to sustained high concentrations of HCFC-123 is known to be hepatotoxic. We report two simultaneous cases of toxic hepatitis related to exposure to 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), a common refrigerant, at a Korean fire extinguisher manufacturing facility. Case presentation Patients A and B were men aged 21 and 22 years, respectively, with no notable medical ...

2008
Shaobo Jia

It is well-known that HCFC refrigerants widely used in today’s air conditioning and refrigeration (AC&R) industry will soon be phased out, mainly due to their ozone depletion potentials (ODPs) and global warming potentials (GWPs). The timetable established through international agreement and national legislation calls for a 65% reduction of HCFC consumption based on 1989 level by January 1, 201...

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