The problem of low-frequency sound propagation in slowly varying ducts is systematically analyzed as a perturbation problem of slow variation. Webster’s horn equation and variants in bent ducts, in ducts with nonuniform soundspeed, and in ducts with irrotational mean flow, with and without lining, are derived, and the entrance/exit plane boundary layer is given. It is shown why a varying lined ...

The article shows the effect of torsional rigidity of beam elements onto spatial work of bridges, floorings and other plate-ribbed systems It is shown that, in determining the torsional rigidity using existing methods it is necessary to have spatial spiral cracks, but torsional rigidity when normal cracks is not researched. A method is described for determining the torsional rigidity of reinfor...

background: rupture into the biliary ducts is the most frequent complication of hydatid liver disease. in endemic areas of echinococcus granulosus, development of jaundice in a patient with liver cyst is initially suspected to have hydatid cyst. case presentation: a 48 year-old woman with history of asymptomatic hydatid liver cysts was admitted to the emergency department with right upper quadr...

MR cholangiopancreatography (MRCP) is an imaging technique that has evolved over the past 2 decades and that continues to have a fundamental role in the non-invasive detection of morphologic features of the pancreatic ducts. In several studies, MRCP has shown a good correlation with endoscopic retrograde cholangiopancreatography in the evaluation of diseases and anatomic variants of the pancrea...

The transitional epithelium lining the ducts of various glands such as salivary and mammary glands, and organs such as liver, pancreas, kidney and lung must bear a permeability barrier as they are in direct contact with the hostile environment in the lumen. The barrier function of pancreatic ductal epithelium is essential for preventing the back flux of proteases, lipases and DNAases from the p...

In this study, the convective heat transfer and pressure drop in laminar flow of Al2O3/water and CuO/water nanofluids through square and triangular cross-sectional ducts have been numerically investigated using new technique. It has been assumed that there is constant heat flux boundary condition at walls. In addition, to include the presence of nanoparticles, the dispersion model has been used...

In this work, we use the homogenization theory to investigate the capability of wavy riblet patterns to influence the behaviour of a viscous flow near a ribbed boundary. Starting from perfect slip conditions on the wall, we show that periodic oscillations of wavy riblets in the lateral direction may induce a friction effect in the direction of the flow, contrary to what happens with straight ri...

BACKGROUND This retrospective study aimed to investigate the incidence of each type of accessory hepatic duct by drip infusion cholangiography with CT (DIC-CT). METHODS Five hundred sixty nine patients who underwent preoperative DIC-CT and laparoscopic cholecystectomy were reviewed. Accessory hepatic ducts were classified as follows: type I (accessory hepatic ducts that merged with the common...

The rotary energy recovery device (RERD) is an essential component in seawater desalination for decreasing the consumption of reverse osmosis plants. To research complex flow fields and mixing motion ducts a device, 3D numerical simulation was studied this work. Three-dimensional vortex structures were visualized identified based on Q criterion. effects operating condition structure parameter h...