scoure is the removal of particle sediment which results variation of flow pattern. local scour is considered as one of the reasons of instability and ultimately failure of bridges.therefore, proposing some controlling methods to reduce this phenomenon is essential. in the study, effects of two types of squar and circular collar on a single cylindrical model have been investigated. in the next ...

Taiwan is located in the rim of the Pacific Ocean. The activities of the earthquake happen frequently, which threaten the safety of the bridge in the Taiwan Island. Besides, the severe floods resulted from the typhoon or storm events can cause great damages due to the bridge scouring. The steep-sloped rivers and sand mining problems in Taiwan accelerate the degradation of the riverbed. Scouring...

this paper presents a k- turbulence model for simulation of steady current and itsinduced vortex shedding caused by the presence of an offshore pipeline. performance of the modelaround a circular cylinder above a wall with gap to diameter ratios of 0.1, 0.35 and 0.5 underdifferent flow regimes with reynolds numbers of 1500, 2500 and 7000 is studied. the flow field iscomputed with solving the re...

Subpopulations of peripheral leukocytes and cytokine mRNA expression levels were evaluated in scouring and healthy Holstein calves (age 10 ± 5 days; n=42) treated with a probiotic consisting of Lactobacillus plantarum, Enterococcus faecium and Clostridium butyricum. The calves were assigned to the scouring or healthy group and then subdivided into pathogen-positive treated (n=8), pathogen-posit...

Local scour around a cylindrical pier in a channel with an erodible bed or natural bed is a common problems in bridge or pile supported structure. The highly unsteady complex flow field around a circular pier produces scour hole mainly for the presence of vortices. The main mechanism that drives the formation and evolution of the scour hole around bridge pier is horse shoe vortex motion. In the...

investigation on local scour phenomenon downstream of impinging jets is very complicated. different parameters such as geometry of stream, characteristics of flow and sediments have great influences on the scour phenomenon. the present study is preceded to numerical modeling of scouring by impinging jet via ssiim 2 model founded on a physical model tests. the numerical model is calibrated for r...

There have been reports in the literature of acute and chronic silicosis and connective tissue disease induced by occupational exposure to silica in factories producing scouring powder. Reports of connective tissue diseases induced by intentional inhalation of such a powder are rare and perhaps underestimated. We report the case of a young woman who developed Sharp's syndrome 5 yrs after diagno...