introduction: surface roughness can increase the retention of castings by ridges and grooves that are microretentive. this study compared the retention of implant-supported crowns when used with 3 different surface roughness abutments and one temporary cement. methods: thirty solid abutments (iti), 4 mm high, were divided into three groups randomly. in the first group, 10 abutments were roughen...

histological and histochemical studies on the pancreas of goose (anser albifrons) were carried out using special staining and light microscope. the pancreas in goose is serous tubuloacinar gland having exocrine and endocrine part. smooth muscle fibres were absent in capsule of pancreas. acinar cells have bizonal shape. intralobular ducts, interlobular and main excretory ducts were present withi...

The non-orthogonal boundary-fitted coordinate transformation method is applied to the solution of steady three-dimensional momentum and energy equations in laminar flow to obtain temperature field and Nusselt numbers in the thermal entry region of straight ducts of different cross sectional geometries. The conservation equations originally written in Cartesian coordinates are parabolized in the...

Sound transmission through ducts of constant cross section with a uniform inviscid mean flow and a constant acoustic lining (impedance wall) is classically described by a modal expansion, where the modes are eigenfunctions of the corresponding Laplace eigenvalue problem along a duct cross section. A natural extension for ducts with cross section and wall impedance that are varying slowly (compa...

Ducts are widely used in an industry field. For example, air conditioning ducts, exhaust smoke elimination ducts and silencers have been various ducts. In general, the a flow vortices generated duct sometimes cause resonance phenomenon self-sustained tone. Once occurs, high level sound is suppression of this strongly quickly required. It necessary to know natural acoustic frequency for examinat...

a total of 1500 infected liver with f. hepatica and f. gigantica from slaughtered cattle in different parts of iran were studied. grossly the livers were usually irregular in shape, with prominent bile ducts on the visceral surface as grayish-white, firm-branching streaks. the atrophy of the left lobe due to fibrosis and ischemia were noticed. on the cut surface the main bile ducts wall consist...