Search results
Results from the WOW.Com Content Network
HFCs replaced older chlorofluorocarbons such as R-12 and hydrochlorofluorocarbons such as R-21. [2] HFCs are also used in insulating foams, aerosol propellants, as solvents and for fire protection. They may not harm the ozone layer as much as the compounds they replace, but they still contribute to global warming --- with some like ...
If released, HFCs stay in the atmosphere for decades and both PFCs and SF 6 can stay in the atmosphere for millennia. The total atmospheric concentration of F-gases, CFCs, and HCFCs has grown rapidly since the mid-twentieth century; a time which marks the start of their production and use at industrial scale.
Compared to HCFCs and HFCs, HFOs have shorter tropospheric lifetimes due to the reactivity of the C=C bond with hydroxyl radicals and chlorine radicals. [1] This quick reactivity prevents them from reaching the stratosphere and participating in the depletion of good ozone, leading to strong interest in the development and characterization of ...
A special numbering system is to be used for fluorinated alkanes, prefixed with Freon-, R-, CFC- and HCFC-, where the rightmost value indicates the number of fluorine atoms, the next value to the left is the number of hydrogen atoms plus 1, and the next value to the left is the number of carbon atoms less one (zeroes are not stated), and the ...
As non-ozone-depleting chemicals, they were developed originally as a replacement for CFCs, HFCs, HCFCs, and PFCs. [1] [unreliable source?] They are typically colorless, odorless, tasteless, low toxicity, low viscosity, and liquid at room temperature. The boiling point of HFEs vary from 50 °C to nearly 100 °C. Although 3M first developed HFEs ...
Main page; Contents; Current events; Random article; About Wikipedia; Contact us
The Clinical Care Classification System was developed from a research study conducted by Dr. Virginia K. Saba and a research team through a contract with the Health Care Financing Agency (HCFA), [24] currently known as the Centers for Medicare and Medicaid Services (CMS). The objective was to develop a computerized method for assessing and ...
RX Systems, now EMIS Health, is a supplier of software to pharmacists. The ProScript and ProScript Connect software systems are community pharmacy dispensary management systems, managing the dispensary process, labelling and endorsing patient records, ordering and stock control.