Eustachian tube function is important in pressure regulation of the middle ear. The efficacy or magnitude of pressure equilibration by tube openings should be determined by the gradient between middle ear and ambient pressure, but in theory also the duration of the tube opening may play a role. This study employed direct measurements of middle ear pressure in patients, who after parotidectomy h...

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an...

The helical steam generator is connected to an HTGR-type nuclear reactor called PeLUIt-40 for production. Steam used generate electricity and hydrogen. A once-through tube bundle was employed because of its ability endure mechanical stress due thermal expansion, high resistance flow-induced vibrations, better performance compared a straight one. To produce the targeted steam, design analysis ne...

In the present study, the effective parameters of water-Al2O3 nanofluid flowing in flat tubes are investigated using the EFAST Sensitivity Analysis (SA) method. The SA is performed using GMDH type artificial neural networks (ANN) which are based on validated numerical data of two phase modeling of nanofluid flow in flat tubes. There are five design variables namely: tube flattening (H), flow ra...

The pressure drop of refrigerant R-134a flow boiling inside a horizontal tube has been investigated experimentally. The test set-up which was used in this investigation is a well instrumented vapor compression refrigeration system. These instruments are thermocouples, flow meter, pressure gauges and the pressure drop measuring apparatus. This system consisted of three electrically heated evapor...

The purpose of this work is to develop a reasonably detailed dynamic model of a Lurgitype industrial methanol synthesis reactor so as to determine important simplifications, to identify application/operating model limits, and to preliminary check the feasibility for the Nonlinear Model Predictive Control (NMPC) methodology. To do so, a Partially Differential Equation (PDE) system is formulated ...

Hydroxycarbonyls arising from OH-initiated reactions of isoprene have been quantified by the technique of a flow reactor coupled to proton-transfer reaction mass spectrometry (PTR-MS) detection. The yields of C5- and C4-hydroxycarbonyls are (19.3 +/- 6.1)% and (3.3 +/- 1.6)%, respectively, measured at a flow tube pressure of about 100 Torr and at a temperature of 298 +/- 2 K. A yield of (8.4 +/...

In order to obtain reliable kinetic parameters, it is required to measure the reaction kinetics of important heterogeneous reactions at ambient relative humidity (RH). In this study, the uptake coefficients and HONO yields for the heterogeneous reaction of NO2 on kaolin and hematite were measured at RH from 7% to 74% and at ambient pressure in the dark using a coated-wall flow tube reactor. The...