application of structures of flow pattern modification is one of the erosion control methods in bends. triangular vanes are among these structures which provide less scour depth compared to the other techniques such as spur dike. since little information on erosion and sedimentation pattern around triangular vanes are available, this study was conducted to study the effect of structure effectiv...

A simple mathematical expression is presented to describe cavitation mean depth of erosion versus time for cavitating jets and ultrasonic cavitation. Following normalization with a characteristic time, t*, which occurs at 75% of the time of maximum rate of erosion, and a corresponding material characteristic mean erosion depth, h*, the normalized erosion depth is related to the normalized time ...

The aim of the present study was to investigate the abrasive effect of CaCO3 and SiO2-based fluoride-free experimental toothpastes on eroded human permanent dental enamel and evaluate the effectiveness of waiting periods between acid exposure and tooth brushing. Twelve volunteers wore palatal appliances containing human enamel blocks for two periods of five days each. The appliances were immers...

BACKGROUND The aim of this study was to investigate the influence of etching time with 15% hydrochloric acid (HCl) on the enamel surface destruction by studying the resulting roughness and erosion depth. METHODS The vestibular surfaces of 12 extracted, caries free human incisors were divided into four quadrants, and each quadrant was etched with 15% HCl for different numbers of etching cycles...

A protocol for three-dimensional molecular thin-film analysis is described that utilizes imaging time-of-flight secondary ion mass spectrometry and large-area atomic force microscopy. As a test study, a 300-nm trehalose film deposited on a Si substrate was structured by bombardment with a focused 15-keV Ga+ ion beam and analyzed using a 40-keV C60+ cluster ion beam. A three-dimensional sputter ...

Molecular time of flight secondary ion mass spectrometry (ToF-SIMS) imaging and cluster ion beam erosion are combined to perform a three-dimensional chemical analysis of molecular films. The resulting dataset allows a number of artifacts inherent in sputter depth profiling to be assessed. These artifacts arise from lateral inhomogeneities of either the erosion rate or the sample itself. Using a...