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Water Condensation (water + condensation)

Distribution by Scientific Domains

Chemistry	75%

Selected Abstracts

Clinical application of continuous spirometry with a pitot-based flow meter during equine anaesthesia

EQUINE VETERINARY EDUCATION, Issue 7 2010
Y. P. S. Moens
Summary This report documents the feasibility and clinical information provided by a new method for spirometric monitoring adapted for equine anaesthesia. Monitoring of ventilatory function was done with continuous spirometry during general anaesthesia of client-owned horses presented for various diagnostic and surgical procedures. An anaesthetic monitor with a spirometry unit for human anaesthesia was used. To allow the measurement of large tidal volumes, a remodelled larger version of the pitot tube- based flow sensor was used. This technology provided reliable spirometric data even during prolonged anaesthesia when water condensation accumulated in the anaesthetic circuit and the sensor. In addition to flow and volume measurement and respiratory gas analysis, the continuous display of flow-volume and pressure-volume loops offered visually recognisable information about compliance, airway resistance and integrity of the circuit. Continuous spirometry with this monitoring system was helpful in evaluating the efficacy of spontaneous ventilation, in adjusting intermittent positive pressure ventilation and detecting technical faults in the anaesthetic apparatus and connection with the patient. This adapted spirometry method represents a practical and reliable measuring system for use during equine anaesthesia. The variety of information provides an opportunity to optimise anaesthetic management in this species. [source]

Modeling of coupled mass and heat transfer through venting membranes for automotive applications

AICHE JOURNAL, Issue 2 2009
Amine Barkallah
Abstract Experimental and theoretical approaches based on a mathematical model, have been developed to study the evolution of environmental parameters (temperature, total pressure, relative humidity, and water vapor partial pressure) inside a housing of an electronic device with a window containing a macroporous membrane. The model was based on the coupling of mass and heat transfer taking into account the effects of polarization of concentration in boundary layers. Membranes have been characterized by mercury porosimetry, liquid entry pressure measurements, scanning electron microscopy, and gas permeation. Once the model was experimentally validated, it was applied to investigate the influence of membranes on heat and mass transfer and to study the impact of the boundary layers on the global mass transport. The results demonstrated the importance of the membrane choice and dimensions to get the best temperature regulation and avoid water condensation inside an automotive electronic control unit (ECU). © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source]

Numerical model for polymer electrolyte membrane fuel cells with experimental application and validation

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2009
Javier Alonso Mora
Abstract The aim of this paper is to present a simple 3D computational model of a polymer electrolyte membrane fuel cell (PEMFC) that simulates over time the heat distribution, energy, and mass balance of the reactant gas flows in the fuel cell including pressure drop, humidity, and liquid water. Although this theoretical model can be adapted to any type of PEMFC, for verification of the model and to present different analysis it has been adapted to a single cell test fixture. The model parameters were adjusted through a series of experimental tests and the model was experimentally validated for a well-defined range of operating conditions: H2/air O2 as reactants, flow rates of 0.5,1.5 SLPM, dew points and cell temperatures of 30,80 °C, currents 0,5 A and with/without water condensation. The model is especially suited for the analysis of liquid water condensation in the reactant channels. A key finding is that the critical current at which liquid water is formed is determined at different flows, temperatures, and humidity. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source]