this study represents effect of four variables in performance of a heat-pump in two cities of tehran and rasht. a computer program has been developed, simulating a certain heat pump acting in different environments with different refrigerants in heating season. the analysis is based on a homogeneous model. effect of different refrigerants, depth of the buried heat exchangers and moisture conten...

The effect of a heat and moisture exchanger, a device with hygroscopic material for conditioning inspired air, on hyperpnoea induced bronchoconstriction was studied in nine non-smoking volunteers with asthma, aged 19-32 years. Each had previously shown an increase of at least 100% in specific airways resistance (sRaw) to isocapnic hyperpnoea with dry air. On two separate days the subject perfor...

Increasing efficiency and decreasing cost are the main purposes in the design of the power generation systems. In this study two hybrid systems: solid oxide fuel cell (SOFC)-gas turbine (GT) and SOFC-GT-steam turbine (ST); are considered. Increasing the SOFC input temperature causes thermodynamics improvement in the hybrid system operation. For this purpose, using two set of SOFC reactants heat...

In 1991, heat-and-moisture exchangers were introduced with biweekly ventilator circuit tubing changes, resulting in elimination of multiple pieces of respiratory equipment and reduced labor costs. The annual savings were $157,000, totalling $1.5 million since the onset of the program. There have been no increases in rates of ventilator-associated pneumonia.

The efficiencies of airway heat and moisture exchanging filters in reducing respiratory water losses and increasing airway temperatures during general anesthesia were studied in five tracheally intubated patients given isoflurane, nitrous oxide, and oxygen anesthesia during controlled ventilation. Filters (Humid-Vent Filter, Humid-Vent 1, Pall Conserve, Siemens 150, and ThermoVent 600) were pla...