Reference

Urban-nonurban relationships of halocarbons, sulfur hexafluoride, nitrous oxide, and other atmospheric trace constituents

Urban-nonurban relationships of halocarbons, sulfur hexafluoride, nitrous oxide, and other atmospheric trace constituents. Singh, Hanwant Bir; Salas, L.; Shigeishi, H.; Crawford, A. (Stanford Res. Inst., Menlo Park, Calif., USA). Atmos. Environ., 11(9), 819-28 (English) 1977. CODEN: ATENBP. ISSN: 0004-6981. DOCUMENT TYPE: Journal CA Section: 59 (Air Pollution and Industrial Hygiene) The May 1976 northern hemispheric continental US background concns. of CCl2F2 [75-71-8], CCl3F [75-69-4], CHCl2F [75-43-4], CCl2FCClF2 [76-13-1], SF6, CCl4 [56-23-5], CHCl3 [67-66-3], MeCl [74-87-3], MeI [74-88-4], MeBr [74-83-9], MeCCl3 [71-55-6], Cl2C:CCl2 [127-18-4], ClCH:CCl2 [79-01-6], COCl2, and NO2 were detd. The ambient burden of CCl2F2 and CCl3F increased at an av. rate of 1.6 ppt (parts per trillion) per mo (11% per yr) and 1.3 ppt/mo (15% per yr), resp., during the first half of 1976. The urban-nonurban relations of these and other pollutants (NO, NO2, TNMHC, O3, CH4 [74-82-8], and CO) were discussed based on a total of 6 short-term field studies conducted in California at both urban and clean air locations. Significant concn. gradients of CHCl3, MeCl, MeI, and MeBr between marine and continental air masses suggest a marine source; for CHCl3 this gradient may be caused by coastal water contamination. Seasonal variations of MeI and probably MeBr exist in the marine environment. N2O and CCl4 are uniformly distributed with no significant temporal or spatial variations. The contribution of fluorinated species to the tropospheric Cl budget (northern hemisphere) in 1976 was ~33%, which is comparable to a 28% natural Cl contribution due solely to MeCl.

Pick up energy from low heat sources

Pick up energy from low heat sources. Shepherd, D. G. (Cornell Univ., Ithaca, N. Y., USA). Hydrocarbon Process., 56(12), 141-9 (English) 1977. CODEN: HYPRAX. ISSN: 0018-8190. DOCUMENT TYPE: Journal CA Section: 52 (Electrochemical, Radiational, and Thermal Energy Technology) Section cross-reference(s): 48 Three working fluids were examd. in the application of binary cycles in using the energy available at low temp. levels. The 3 fluids were R-21 (refrigerant) [75-43-4], isobutane [75-28-5], and Fluorinol 85 [60251-53-8]. Conditions apply primarily to the geothermal use but the results and evaluation techniques are of interest for any application for recovery of low-temp. level energy.