Ventilator-associated pneumonia (VAP) is a common and serious complication of mechanical ventilation via an artificial airway. As with all nosocomial infections, VAP increases costs, morbidity, and mortality in the intensive care unit (ICU). VAP prevention is a multifaceted priority of the intensive care team, and can include the use of specialized artificial airways and heat-and-moisture excha...

In this study, the effect of the tube material on the thermal stress generated in a vertical shell and tube heat exchanger is investigated. Shell and tube heat exchangers are the most common heat exchangers used in industries. One of the most common failures in these exchangers in the industry is the tube failure at the junction of the tube to tubesheet. When the shell side and the tube side fl...

the present study investigated the effect of distilled-water/ silver nanofluid on heat transfer in a closed cooling system of one of the electrical energy generation units at isfahan power plant. the difference between this study and previous researches refers to silver properties which have a high thermal conductivity and is non-toxic, hydrophilic and eco-friendly. distilled water/ silver nano...

Fouling of heat exchangers is a severe problem in the industrialized world. The effects of fouling are reduced energy efficiency and increased greenhouse gas emissions. In fact, any heat transfer process has a risk of fouling on the heat transfer surface. The fouling can in some cases be cleaned physically, chemically or burned off; in other cases it may not be possible to clean the heat exchan...

The forced convection heat transfer in high porosity metal-foam filled tube heat exchangers are studied in this paper. The Brinkman Darcy momentum model and two energy equations for both solid and fluid phases in porous media are employed .The study shows that using metal-foams can significantly improve the heat transfer in heat exchangers. Keywords—metal foam, Nusselt number, heat exchanger, h...

Jet-refrigeration cycles seem to provide an interesting solution to the increasing interest in environment protection and the need for energy saving due to their low plant costs, reliability and possibility to use water as operating fluid. A steam/steam ejector cycle refrigerator is investigated introducing a two-stage ejector with annular primary at the second stage. The steady_state refrigera...

leather manufacturing involves a crucial energy-intensive drying stage in the finishing process to remove its residual moisture. determining drying characteristics of leather is vitally important so as to optimize the drying stage. this paper describes an analytical way for determination of the drying characteristics of leather. the model presented, is based on fundamental heat and mass transfe...