Refrigeration effect research

Much research is being conducted to find alternatives to CFCs with little or no effect on the ozone layer. Among these are HCFC-123 (HCCI2CF3) to replace Freon-11 and HCFC-22 (CHCIF2) to replace Freon-12 in such uses as air conditioning, refrigeration, aerosol, and foam. These compounds have a much lower ozone depletion value compared to Freon-11, which was assigned a value of 1. Ozone depletion values for HCFC-123 and HCFC-22 relative to Freon-11 equals 0.02 and 0.055, respectively. ... 

Refrigerators and air conditi-ioners function because of the relationship between pressure and temperature. Research the Joule-Thomson Effect. Go to the web site above. Go to Science Resources, then to Chemistry 11 to find out where to go next. 

Tetrafluorochloroethane (HCFC-124 CF3CHCIF) is a potential replacement in refrigeration and solvent applications, either as a pure compound or as a component of a blend or azeotrope. Several of the methods and catalytic systems discussed in Section II,B have been applied for the synthesis of HCFC-124. Research focus has been on optimization of operational parameters and also the development of specific catalysts for product maximization. In addition, one can also use HCFC-123 as a starting material or a pentahaloethane instead of PCE. Manzer and Rao (65) have reported that a cobalt salt on alumina, which is fluorided prior to use, is an effective catalyst for the conversion of pentahaloethanes to HCFC-123 and... 

Saude and Sykes [97] studied the effects of preparation and storage on the stability of human urine for metabolomic studies. Urine samples were collected from healthy male and female subjects and prepared by four different procedures (raw, centrifuged, filtered, and containing the bacteriostatic preservative sodium azide) and analyzed by NMR. The samples were stored at three different conditions at room temperature (22°C), in a refrigerator (4°C), or in a deep-freezer (-80°C) and changes in concentrations of 55 metabolites were monitored every week for one month. The researchers concluded that samples should be stored in a deep freeze (-80°C) and the number of freeze-thaw cycles should be minimized as much as possible. Bacterial contamination of the urine had significant changes on urinary metabolites and could be controlled by either filtration (MS-based analyses) or by the addition of sodium azide (NMR-based analyses). 

Plaza, L., Sanchez-Moreno, C., Elez-Martinez, R, de Ancos, B., Martm-Belloso, O., and Pilar Cano, M. 2006. Effect of refrigerated storage on vitamin C and antioxidant activity of orange juice processed by high-pressure or pulsed electric fields with regard to low pasteurization. European Eood Research and Technology 223 487 93. 

Hazardous Decomp. Prods. poisonous gases incl. NOx are produced in fire Storage Store under refrigeration in tightly closed containers away from ignition sources Uses Research chemical laboratory synthesis of diazomethane cancer medication possible antineoplastic agent used for mutagenic effects on various plants... 

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