OBJECTIVE To compare the bronchodilator effectiveness of albuterol reformulated in the chlorofluorocarbon-free propellant hydrofluoroalkane (HFA)134a (Proventil HFA) to that of Ventolin and HFA placebo over 12 weeks of regular dosing. DESIGN Randomized, double-blind, double-dummy, parallel group, placebo-controlled, multi-center trial of asthmatics requiring inhaled beta-adrenergic bronchodil...

SUMMARY This paper is one input to respond the Council request of 10 October 2000 to " study and prepare measures in reduction of all greenhouse gas emissions from air conditioning in vehicles ". Greenhouse gas emissions due to mobile air conditioning are significant and growing fast in the European Union. The European Commission estimates that the emission will be between 31 and 53 Mt CO 2 eq ...

The awareness to protect the environment from the harmful effects of CFCs has motivated the refrigeration scientists and engineers to study alternative refrigerants to replace the CFCs even in the existing units. This paper presents a thermodynamic study of hydrocarbon blends (Propane/lsobutane) and blends of HFC-134a-HC-600a as a possible "drop-in" (some electrical component to be changed to m...

A numerical simulation of a liquid overfeed system working with pure refrigerants in steady state conditions has been performed. The global algorithm is based on the sequential resolution of the different elements of the system (compressor, evaporator, condenser, ... ). For each element, a simplified mathematical model based on global balances of mass, momentum and energy is used. For the evapo...

Solubility (vapor pressure) , viscosity and density have been experimentally determined for thirty-five potential refrigeration working fluids. Properties for low refrigerant concentration mixtures (0, 10, 20 and 30 weight percent refrigerant) were determined over the temperature range 0 to IOO•C (32 to 212"F) or to the critical temperature of the refrigerant, and pressure range 0 to 3,500 kPa ...

The popularity of vehicles and the increased time spent in cars with air conditioning systems has led to regulations many countries that require use environmentally friendly refrigerants minimal global warming zero ozone depletion potential (GWP ODP). Cars need high-performance, eco-friendly reduce their impact on environment, lower fuel consumption, decrease carbon emissions. aim current work ...