This review presents the nucleate/convective boiling performance for a variety of important low global warming potential (LGWP) alternatives to commonly used high-global (GWP) refrigerants (such as R-134a, R404A, and R-410A, etc.). Efforts are stressed on assessment their evaporation pressure drop heat transfer coefficient (HTC) characteristics. These include R-1234ze(Z), R-1234ze(E), R-1233zd ...

In the present work, various objective functions were formulated and optimized using mixed integer nonlinear programming generalized reduced gradient method from solver tool of Microsoft® Excel 2016, respectively. The CH3FO2, C2H4F2O, CH2F2O2, CH2F2O, C3H4F2, C2H2F2O molecules found to meet structural feasibility constraints physical properties refrigerant have not previously been reported in l...

STUDY OBJECTIVE s: To compare the effect of 4 weeks of treatment with fluticasone propionate (FP), 100 micro g bid, delivered either via the Diskhaler (GlaxoSmithKline; Middlesex, UK) or a hydrofluoroalkane (HFA)-134a pressurized metered-dose inhaler (pMDI) on airway responsiveness. DESIGN A single-center, randomized, double-blind, double-dummy, placebo-controlled crossover study. SETTING O...

The Kigali Amendment to the Montreal Protocol limits global use of fluorinated greenhouse gases (F-gases) and encourages development a new generation refrigerants with lower warming potential. Therefore, there is need develop efficient sustainable technologies selectively capture recycle F-gases as environmentally refrigerants. Here, ionic liquids (ILs) high F-gas uptake capacity selectivity we...

In this study, condensation heat transfer coefficients (HTCs) of HCFC22, HCFC123, HFC134a and HFC245fa are measured on a horizontal plain tube 19.0 mm outside diameter. All data are taken at the vapor temperature of 39 with a wall subcooling temperature 3-8 . Test results show the HTCs of newly developed alternative low vapor pressure refrigerant, HFC245fa, on a smooth tube are 9.5% higher than...

In accordance with worldwide consensus, the use of chlorofluorocarbons, which play an important role in damaging the ozone layer, should be completely abolished by the end of 1995. This provided the impetus for developing the three vane rotary compressor. Formerly CFC-12 was used as the refrigerant in automotive air conditioners, until HFC-134a was substituted for CFC-12. In response to the cha...

This work presents results from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) study. Whole air samples were obtained on board research flights that flew over California during June 2008 and analyzed for selected volatile organic compounds, including several halogenated species. Samples collected over the South Coast Air Basin of California ...

Hydro-fluorocarbons (HFCs) that are not harmful to ozone layer and used in many appli-cations, including as refrigerants, aerosols, solvents blowing agents for insulating foams replace chlorofluorocarbons hydro (HCFCs). However, some HFCs have a high GWP, which stands “Global Warming Potential(GWP).” Because of the grow-ing concern over global climate change, researchers paying closer attention...