In this study, a quasi-realistic thermodynamic analysis was performed to investigate the effects of design and operating parameters on performance single-cylinder modern Atkinson cycle engine. Fortran used for all calculations. It assumed that fuel-air mixture as working fluid, iso-octane fuel. The Wiebe function combustion process it specific heat fluid varies with temperature. calculations, t...

BACKGROUND The aim of this study was to evaluate the relationship between aortic valve area (AVA) obtained by Doppler echocardiography and outcome in patients with severe asymptomatic aortic stenosis and to define a specific threshold of AVA for identifying asymptomatic patients at very high risk based on their clinical outcome. METHODS AND RESULTS We included 199 patients with asymptomatic s...

We evaluated dilation technique (n=80) and aortic valve morphology by two-dimensional echocardiography (n = 58) in patients with congenital aortic valve stenosis to determine their influence on outcome. Patients' age (9 ± 9 years; range, 1 day-39 years) and a history of surgical valvotomy did not influence outcome. The number of dilating balloons (one vs. two) and balloon:annulus ratio based on...

Cavitation has been investigated in directional control valves in order to identify damage mechanisms characteristic of components o f aircraft hydraulic systems. Tests have been conducted in a representative metal spool valve and in a model three times larger. Data taken under noncavitating conditions with both valves showed that the position of the high-velocity annular jet shifts orientation...

Two dominant types of congenital bicuspid valves are described. The classical type is characterized by the presence of a low ridge or raphe along the aortic aspect of the conjoined cusp. The other is characterized by a tall raphe, the upper edge of which corresponds with the upper level of the aortic cusps. Some such ridges may result from acquired fusion of the adjacent halves of two cusps (yi...

One hundred and six patients who left hospital after Starr-Edwards ball valve replacements have beenfollowedfor a period of 6 months tO 4 years. All patients were maintained on oral anticoagulant therapy so that a prothrombin ratio of approximately I 7:I was attained. Four patients suffered minor nose bleeds. During the period offollow-up there have been 4 patients who have suffered embolic phe...

Mitral valve prolapse was sought clinically and with phonocardiography and M mode and sector echocardiography in 15 women aged 22-57 years with joint hypermobility syndrome. The type III:III + I collagen ratio was measured in skin biopsy specimens and was found to be raised in seven of 10 patients sampled. Thirteen patients had increased aortic wall compliance measured by the continuous wave Do...

BACKGROUND In middle income countries, the burden of rheumatic heart disease (RHD) remains high, but the prevalence of other heart valve diseases may rise as the population life expectancy increases. Here, we compared population-based data on surgical procedures to assess the relative importance of causes of heart valve disease in Salvador, Brazil. METHODOLOGY/PRINCIPAL FINDINGS Medical chart...

BACKGROUND Valvular heart disease has been a significant cause of heart disease worldwide. In Ethiopia, it particularly affects young individuals and constitutes the major cause of cardiovascular disease. Factors associated with choice of treatment for advanced valvular heart disease are variable. The objective of this study is to review surgery done for Ethiopian patients with valvular heart d...