INTRODUCTION Studies comparing high frequency oscillatory and conventional ventilation in acute respiratory distress syndrome have used low values of positive end-expiratory pressure and identified a need for better recruitment and pulmonary stability with high frequency. OBJECTIVE To compare conventional and high frequency ventilation using the lower inflection point of the pressure-volume c...

supersonic separators have found extensive applications in dehumidification of natural gases since 2003. unlike previous studies, which have investigated the inlet conditions and nozzle geometry of supersonic separators for pure fluids, the present study employed a combination of momentum, heat, and mass transfer equations along with virial equation of state (eos) to inspect the effect of inlet...

A sound wave traveling in air causes oscillations in pressure above or below the ambient atmospheric pressure. In acoustic theory, a sound source is mainly characterized by its amplitude and frequency (f). The acoustic incident pressure field (p̃) at an observation point, x, due to a point source located at xs is given by Equation 1 where, ω = 2πf , c0 is the speed of sound and S̃ represents the ...

conclusions it seems that there is no difference in the use of heparinized and normal saline solutions to prevent catheter occlusion of arterial and central venous pressure. patients and methods in the current randomized controlled trial, 100 patients, with an age range of 18 - 65 years of valve and coronary artery surgery were studied in rajaie heart center, tehran, iran. patients were randomi...

geothermobarometry equations are based on thermodynamic principles and appear in single or multi-variant functions. the number of variants for a specific composition or reaction usually is reduced into 2 involving temperature (t) and pressure (p). since most of planned equations have two passive or variant p and t, using these equations should be with special care. it is very effective to use g...

in this work, the feasibility study for design of a laboratory sample rde which has an annular geometry with diameter of 76 mm and length of 101 mm has been performed. detonation engines are expected to be used as propulsion system in aerospace applications in the future. several types of detonation engines are currently under examination, including the rotating detonation engine (rde). first, ...

the purpose of this study was to determine the seasonal changes of vital signs (body temperature, pulse rate and blood pressure) in relation to the working thermal conditions. in this study a total number of 202 permanent workers of bakeries were studied during summer and winter. the results showed the body temperature and pulse rate raised more in summer than in winter in all workers except wh...

the usage of turbochargers in diesel engines has led to the downsizing of the motors as well as usage of the waste gates in turbochargers. any dimensional reduction in turbochargers and appurtenant leads to an enhancement on the performance of internal combustion engines and in environmental problems in terms of aerodynamic, thermodynamic and mechanical specifications for both engines and turbo...

BACKGROUND Normal healthy aging results in changes in Doppler indexes of diastolic function. One widely accepted explanation for these alterations that is based on animal data is an age-associated impairment of myocardial relaxation resulting from abnormal myocyte calcium handling. However, an alternative theory based on altered left atrial compliance with aging has been proposed in which early...