CFC photolysis
نویسندگان
چکیده
منابع مشابه
Degradation rates of CFC-11, CFC-12 and CFC-113 in anoxic shallow aquifers of Araihazar, Bangladesh.
Chlorofluorocarbons CFC-11 (CCl(3)F), CFC-12 (CCl(2)F(2)), and CFC-113 (CCl(2)F-CClF(2)) are used in hydrology as transient tracers under the assumption of conservative behavior in the unsaturated and saturated soil zones. However, laboratory and field studies have shown that these compounds are not stable under anaerobic conditions. To determine the degradation rates of CFCs in a tropical envi...
متن کاملThe wall of the chick embryo aorta harbours M-CFC, G-CFC, GM-CFC and BFU-E.
In the 3- to 4-day avian embryo, after the first wave of haemopoiesis which derives in the yolk sac from haemopoietic stem cells formed in situ, haemopoietic cells emerge in an intraembryonic site, the wall of the aorta. In this paper, we demonstrate that this site harbours M-CFC, G-CFC, GM-CFC and late and early BFU-E. In serum-free medium, the growth of M-CFC and GM-CFC was strictly dependent...
متن کاملIs inhaled beclomethasone (BDP) with a non-CFC propellant equivalent to the CFC propellant formulations?
We read with interest the recent article of Milanowski et al. (1) which reported an apparent equivalent anti-asthmatic eect of low (400 mg per day) and high (2000 mg per day) doses of HFA-134a (Norton Healthcare Ltd, London, U.K.) and CFC formulations of beclomethasone dipropionate (BDP). In order to evaluate the relative potency of two inhaled corticosteroid formulations, it is necessary to c...
متن کاملAtmospheric histories and emissions of chlorofluorocarbons CFC-13 (CClF3), 6CFC-114 (C2Cl2F4), and CFC-115 (C2ClF5)
Based on observations of the chlorofluorocarbons CFC-13 (chlorotrifluoromethane), 6CFC-114 (combined measurement of both isomers of dichlorotetrafluoroethane), and CFC-115 (chloropentafluoroethane) in atmospheric and firn samples, we reconstruct records of their tropospheric histories spanning nearly 8 decades. These compounds were measured in polar firn air samples, in ambient air archived in ...
متن کاملImproved airway targeting with the CFC-free HFA-beclomethasone metered-dose inhaler compared with CFC-beclomethasone.
Hydrofluoroalkane-134a (HFA) beclomethasone dipropionate (BDP) was formulated in a metered-dose inhaler (MDI) to deliver a particle size of 1.1 microm compared with 35 microns for currently marketed chlorofluorocarbon (CFC)-BDP products. Two phase I single-dose human deposition studies were conducted using technetium 99m-radiolabelled BDP in a press-and-breathe actuator without an add-on spacer...
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ژورنال
عنوان ژورنال: Nature
سال: 1989
ISSN: 0028-0836,1476-4687
DOI: 10.1038/338456b0