The main objective of this work is to examine the impac.1 of jet interactions in arrays of micropropulsion devices on thrust performance. Rarefied flow of nitrogen and helium from a single orifice and orifice arrays into vacuum was studied experimentally and numerically. The chamber pressure was changed in the range from 10 milli-torr to 40 torr, the orifice diameter was 1 mm, and the center-to...

While color Doppler flow mapping has yielded a quick and relatively sensitive method for visualizing the turbulent jets generated in valvular insufficiency, quantification of the degree of valvular insufficiency has been limited by the dependence of visualization of turbulent jets on hemodynamic as well as instrument-related factors. Color Doppler flow imaging, however, does have the capability...

In the present numerical study, thermal performance and fluid flow properties have been investigated to show effect of single-orifice multiple-orifice impingement synthetic jets for dimensionless orifice-toplate distance (H/D) lower than one. Investigations done an actuation frequency f=500 Hz, 0.10 ≤ H/D 0.75, pitch ratio 1.25 Do/D 1.75. The results were validated with experimental from litera...

UNLABELLED As is commonly understood, the root canal morphology of the maxillary molars is usually complex and variable. It is sometimes difficult to detect the distobuccal root canal orifice of a maxillary second molar with root canal treatment. No literature related to the distobuccal root canals of the maxillary second molars has been published. OBJECTIVE To investigate the position of the...

BACKGROUND The regurgitant volume in aortic regurgitation is determined by the diastolic filling period, the pressure gradient between the left ventricle and aorta, and the hemodynamic size of the regurgitant orifice area. METHODS AND RESULTS To test the hypothesis that the aortic regurgitant orifice area is related to aortic pressure and aortic root size, 16 fresh calf heart and aorta specim...

OBJECTIVES The purpose of the study was to develop and validate an automated method for calculating regurgitant flow rate using color Doppler echocardiography. BACKGROUND The proximal flow convergence method is a promising approach to quantitate valvular regurgitation noninvasively because it allows one to calculate regurgitant flow rate and regurgitant orifice area; however, defining the loc...

Doppler-derived gradients may overestimate total pressure loss in degenerative and prosthetic aortic valve stenosis (AS) due to unaccounted pressure recovery distal to the orifice. However, in congenitally bicuspid valves, jet eccentricity may result in a higher anatomic-to-effective orifice contraction ratio, resulting in an increased pressure loss at the valve and a reduced pressure recovery ...

BACKGROUND AND OBJECTIVES Natural-orifice approaches for nephrectomy have included access via the stomach, vagina, bladder, and rectum. Recently, the feasibility of using the ureter as a natural orifice for natural-orifice transluminal endoscopic surgery nephrectomy has been demonstrated in a nonsurvival porcine model. The purpose of this study was to assess the outcomes of transureteral laparo...

Objective: Two cases in which emergency retrograde stenting were performed for occlusion of the left common carotid artery orifice that occurred during thoracic endovascular aortic repair are reported. Case Presentations: In males in their 70s with thoracic aortic aneurysm, oxygen saturation dropped in the left cerebrum immediately after deployment of the thoracic aortic stent graft under gener...

a 4-day-old holstein bull calf with considerable oedema of the belly (water belly) was referred to theveterinary teaching hospital of the school of veterinary medicine, shiraz university. the owner did notobserve any urination since birth. rupture of the urethra was suspected. perineal urethrotomy was performed. subsequently, catheterization of urethra revealed the obstruction near the external...