Although they represent a valuable alternative to heated humidifiers, artificial noses have unfavourable mechanical effects. Most important of these is the increase in dead space, with consequent increase in the ventilation requirement. Also, artificial noses increase the inspiratory and expiratory resistance of the apparatus, and may mildly increase intrinsic positive end-expiratory pressure. ...

Introduction Is There a Role for Screening Spirometry? Are Corticosteroids Useful in Late-Stage Acute Respiratory Distress Syndrome? Should Patients Be Able to Follow Commands Prior to Extubation? Are Sleep Studies Appropriately Done in the Home? Should Tracheostomy Be Performed as Early as 72 Hours in Patients Requiring Prolonged Mechanical Ventilation? Should Prone Positioning Be Routinely Us...

At many circumstances, in heat exchange processes several exchangers were used with different cost laws due to their pressure ratings, materials of construction and exchange3r types. In such circumstances traditional methods of pinch technology can not be led to minimum total annual cost may cause some other disadvantages like more complexity or higher maintenance. In this research work a n...

As the scale of devices becomes small, thermal control and heat dissipation from these devices can be effectively accomplished through the implementation of microchannel passages. The small passages provide a high surface area to volume ratio that enables higher heat transfer rates. High performance microchannel heat exchangers are also attractive in applications where space and/or weight const...

In air-conditioning and energy-recovery applications, heat exchangers are very important to the overall efficiency, cost, and size of the system. Current heat exchanger designs rely heavily on fin-and-tube or plate heat exchanger designs, often constructed using copper and aluminum. Recent developments in material sciencedin particular, advances in ceramics and ceramic matrix compositesdopen op...

Heat exchangers are the critical components of refrigeration and liquefaction processes. Selection of appropriate operational conditions for cryogenic recuperative heat exchanger and expansion valve operating in Joule-Thomson cooling system results in improving the performance and efficiency. In the current study, a straightforward procedure is introduced to design an efficient Joule-Thomson co...

There are extensive applications of lithium bromide-water absorption chillers in industry, but the heat exchangers corrosion and refrigerating capacity loss are very difficult to be solved. In this paper, an experiment was conducted by using plastic heat transfer tubes instead of copper tubes. As an example, for a lithium bromide-water absorption chiller of refrigerating capacity of 35kW, the c...

Mechanical Engineering) Design with Constructal Theory: Steam Generators, Turbines and Heat Exchangers

An accurate and easy to use test circuit has been developed for the performance evaluation of the heat exchangers used in cardiac surgery during extracorporeal circulation. The water part of the heat exchanger is fixed at a flow rate of 15 l/min and at a temperature of 40 degrees C. In the blood side, the flow rate is varied from 1 to 6 l/min and the temperature is 30 degrees C. The use of a pr...