OBJECTIVE The purposes of this retrospective study were to represent a newly designed theoretical model for determining orifice shape and morphologic properties of mandibular premolars and to correlate these findings with each other. MATERIALS AND METHODS A total of 287 mandibular premolar images obtained from 88 patients by cone-beam computed tomography were included in this study. The measu...

Analysis of velocity acceleration proximal to a regurgitant valve has been proposed as a method to quantify the regurgitant flow rate (Q.). Previous work has assumed inviscid flow through an infinitesimal orifice, predicting hemispheric isovelocity shells, with calculated flow rate given by QC=2rrN2vN, where VN is user-selected velocity of interest and rN is the distance from that velocity to t...

AIM To compare the classical and simplified form of the continuity equation in small Trifecta valves. METHODS This is a retrospective analysis of post-operative echocardiograms performed for clinical reasons after implantation of Trifecta bioprosthetic valves. RESULTS There were 60 patients aged 74 (range 38-89) years. For the valves of size 19, 21 and 23mm, the mean gradient was 11.3, 10.7...

The measurement of a cardiac valve's area is a common procedure, usually performed with noninvasive, Doppler-based techniques. Such measurements are not, however, without problems: a potential source of errors is the value of a valve’s discharge coefficient. In-vitro pressure and flow measurements relative to the bileaflet valve of four brands were performed. A total of 12 valve samples was stu...

Malformations of the Penis Hypospadias is the most common malformation (1 in 250 live male births). It refers to the abnormal location of the distal urethral orifice along the ventral aspect of the penis. The urethral orifice is sometimes constricted, resulting in urinary tract obstruction. Epispadias: the urethral orifice is situated on the dorsal aspect of the penis. Like hypospadias, epispad...

This paper analyses the damping in pressure compensated closed centre mobile working hydraulic systems. Both rotational and linear loads are covered and the analysis applies to any type of pump controller. Only the outlet orifice in the directional valve will provide damping to a pressure compensated system. Design rules are proposed for how the system should be dimensioned in order to obtain a...

A 64 year old woman with partial atrioventricular canal and double orifice mitral valve presented with severe mitral regurgitation secondary to a torn leaflet. The double orifice regurgitant mitral valve is an unusual finding at operation.

The flow field development through a simplified shock absorber orifice geometry is investigated using single phase Large Eddy Simulation. Hydraulic oil used as the working fluid with constant inlet velocity and an open top boundary to allow study focus on free shear layer in vicinity of main orifice. validated standard mixing dynamics. impact shape discussed regards initial growth, potential ap...

OBJECTIVES Proper valve selection is critical to ensure appropriate valve replacement for patients, because implantation of a small valve might place the patient at risk for persistent gradients. Labeled valve size is not the same as millimeter measure of prosthetic valve diameters or the annulus into which it will fit. Studies that use the labeled valve size in lieu of actual measured diameter...