Joule-Thomson cooling systems are used in refrigeration processes such as cryogenic gas liquefaction. Although extensive studies have been carried out by researchers, most of them include cryogenic heat exchangers and their associated fields. In the current study, an attempt was made to indicate the effect of using inappropriate operational conditions in a cryogenic Joule-Thomson cooling system...

It is well recognized that upper airways obstruction by adenotonsillar hypertrophy can lead to cor pulmonale, but delays in diagnosis still occur, leading to an appreciable morbidity and even occasional mortality. In the case presented, echocardiographic recognition of right ventricular enlargement and abnormal pulmonary valve motion served to complement and confirm the clinical diagnosis. Foll...

T he introduction of balloon valvuloplasty for aortic stenosis first reported by Cribier and colleagues in 19861 was initially greeted with enthusiasm, especially by the interventional cardiologists who had in Samsonlike tradition2 crushed the pillars of atherosclerotic coronary arteries with balloon catheters and were now anxious to do the same to calcified aortic valve leaflets. The success o...

Programmable valve shunts allows selection of opening pressure of shunt valve. In the presented article, a unique complication pertaining to programmable shunts has been discussed. A 5-year-old boy who had tectal plate low grade glioma with obstructive hydrocephalus was managed with Codman programmable ventriculoperitoneal shunt. There was a spontaneous change in the opening ...

OBJECTIVE To assess the hydrodynamic properties of three new types of hydrocephalus valve. METHODS Three new constructions have been recently tested in the UK shunt Evaluation Laboratory: the magnetically adjustable Strata Valve (Medtronic PS Medical), the gravitational Miethke Dual-Switch Valve (Aesculap) and the ventriculo-sinus SinuShunt (CSF Dynamics). Pressure-flow performance curves wer...

BACKGROUND AND AIM OF STUDY Pressure gradients across cardiac valve prostheses have been identified as one of the most important performance measures in valve replacement surgery. Specifically in aortic valves, these gradients influence reduction of left ventricular hypertrophy and are postulated to influence long-term survival. The correct choice of replacement valve is hampered by a lack of u...

rx-tHE object of this paper is to discuss the use of nitrous X oxide supplemented with pethidine in the operation of mitral valvotomy for the relief of mitral stenosis. Direct surgery of the stenosed mitral valve is no new conception. Indeed, as far back as the year 1902, Brunton put forward the plea for surgical disruption of the stenosed valve, but he met with such determined opposition that ...

A bisphenol A production plant possesses considerable potential risks in the top of the methanol separation column, as pressurized acetone, methanol, and water are processed at an elevated temperature, especially in the event of an abnormal pressure increase due to a sudden power outage. This study assesses the potential risks in the methanol separation column through hazard and operability ass...