To the Editor:—I read with interest the study by Jaber et al. and the accompanying editorial by Tantawy and Ehrenwerth regarding pressure-support ventilation (PSV). The Jaber study is noteworthy for documenting that the performance of PSV using modern anesthesia ventilators approaches the performance of an intensive care unit ventilator. The editorial correctly indicates that the testing was no...

To the Editor:—I read with interest the study by Jaber et al. and the accompanying editorial by Tantawy and Ehrenwerth regarding pressure-support ventilation (PSV). The Jaber study is noteworthy for documenting that the performance of PSV using modern anesthesia ventilators approaches the performance of an intensive care unit ventilator. The editorial correctly indicates that the testing was no...

The influence of pressure variations upon distillation operation does not seem to be well-understood in the open literature, because contradicting statements concerning the importance of pressure control on binary distillation are found. To minimize energy consumption, it is recommended to operate columns at minimum pressure; however, even if column pressure is controlled, instability may still...

A scroll compressor has a bu~lt-in pressure ra~~o related to geometry of scroll wraps and efflciency of the compressor depends on the relation between the ratio and an operat~ng pressure rat~o. Th~s paper analyses theoretl.cal performance of the compressor by tak1ng account of flow resistances at opem.ngs of scroll wraps and leakage flows through wrap clearances. The flow resl.stance at the d1s...

Chemical Vapor Deposition (CVD) is one of the most popular methods for producing Carbon Nanotubes (CNTs). The growth rate of CNTs based on CVD technique is investigated by using a numerical model based on finite volume method. Inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as carrier gas enters into a horizontal CVD reactor at atmospheric pressure. In thi...

Background: Clinical investigations have reported several anesthetic properties of intrathecal injections of meperidine. The purpose of this study was to investigate the effect of adding meperidine to intrathecal heavy lidocaine on hemodynamic changes and blood loss in patients undergoing elective suprapubic open prostatectomy. Methods: In a randomized double-blind clinical trial, 77 pa...

When a natural gas pipeline ruptures, the adjacent upstream and downstream automatic control valves (ACV) should close quickly to prevent leakage or explosion. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in ACV actions. If the DPS is not properly adjusted, the ACV may mistakenly close or it may not take any actions at a proper ti...

Tremendous efforts have been devoted to study the complex phenomenon "knock in spark ignition engines. There is an increasing interest in providing some tools to study knock in simulated data. In the previous studies, engine cylinder pressure oscillation has been used to investigate knock. Unless those methods involved highly complex non-detailed chemical relations, the previous studies were de...