This paper investigates the effects of nonazeotropic refrigerant mixtures (NARMs) as replacement of CFCs. The thermodynamic propert1es of NARM R22/R142b which is harmless to ozone layer are analyzed. The tests about water-to-water heat pump and dual-evaporator refrigerator-freezer using R22/R142b as alternative to R12 are introduced. The test results show R22/Rl42b is of energy conserving effec...

Two multiple-tracer tests were conducted at The Geysers to evaluate the relative properties of various gas tracers with respect to tritiated water. In this study the geographic distribution of the tracer responses in the two tests are compared. The DV-11 test, which was conducted in 1994, used the chlorofluorocarbon R-13 and SF6. The P-1 test used the newly developed hydrofluorocarbon tracers R...

The title compound, C(6)H(10)N(8)S(2), was prepared by the nucleophilic substitution reaction of 5-mercapto-1-methyl-tetra-zole and dichloro-ethane. In the crystal, the mol-ecule possesses an approximate non-crystallographic twofold symmetry axis. The crystal packing is stabilized by weak inter-molecular C-H⋯N and π-π inter-actions [centroid-centroid distances = 3.448 (6), 3.5085 (5) and 3.4591...

Dr. Maxwell is a visiting scholar at the Center for International Studies at MIT and Director of the Center for Environment and Health at John Snow, Inc He received his Ph.D. in the field of Public Policy at MIT. He is currently supervising studies of siting in US and foreign countries, integration of environment and health in policy making, and environmental management practices in the automob...

1. Ozone and Climate: A Review of Interconnections .............................................................................................................. 83 2. Chemical and Radiative Effects of Halocarbons and Their Replacement Compounds ..................................................... 133 3. Methodologies ...............................................................................

An analysis of N2O (nitrous oxide) and CFC (chlorofluorocarbon) concentrations (monthly values) at various locations during 1978-2001 indicated seasonal variations. When these were minimized by calculating 12-month running means (12m) 3-year (37m) subtracted from 12m, the residues (12m-37m) showed oscillations with peak spacings in QBO (quasi-biennial oscillation, 2-3 year) QTO (quasi-triennial...

This paper describes the protective action of stratospheric ozone together with different mechanisms causing ozone depletion. Ozone absorbs UV radiation coming from the Sun. Increased UV radiation due to ozone depletion affects people, terrestrial and aquatic ecosystems, materials as well as air quality. Chlorofluorocarbons, halons and methyl bromide are all significant ozone depleting substanc...

Atmospheric hydrofluorocarbon (HFC) abundances are increasing rapidly because of the Montreal Protocol phase-out production and consumption chlorofluorocarbons (CFCs) hydrochlorofluorocarbons (HCFCs). HFC-32 (CH2F2, difluoromethane) mole fractions (volume mixing ratios, VMRs) have been retrieved from infrared absorption spectra recorded orbit with Chemistry Experiment Fourier transform spectrom...