نتایج جستجو برای: sand particle
تعداد نتایج: 201427 فیلتر نتایج به سال:
Surface water, groundwater and sand can flow into mine goaf through the fractured rock, which often leads to water inrush and quicksand movement. It is important to study the mechanical properties of water and sand in excavations sites under different conditions and the influencing factors of the water and sand seepage system. The viscosity of water-sand mixtures under different particle sizes,...
effects of sand mining on suspended sediment particle size distribution in kojour forest river, iran
soil erosion causes sediments to be detached from their source materials and transported as suspended particles. the present study was conducted to evaluate the effects of sand exploitation on the distribution of suspended sediments in the educational and research forest watershed of tarbiat modares university, which comprises approximately 50,000 ha. fifty-one water samples were collected befo...
Wind-blown sand is a typical example of twophase particle-laden flows. Owing to lack of simultaneous measured data of the wind and wind-blown sand, interactions between them have not yet been fully understood. In this study, natural sand of 100–125 lm taken from Taklimakan Desert was tested at the freestream wind speed of 8.3 m/s in an atmospheric boundary layer wind tunnel. The captured flow i...
The protective performance of a sand particle-modified enamel coating on reinforcing steel bars was evaluated in 3.5 wt% NaCl solution by electrochemical impedance spectroscopy (EIS). Seven percentages of sand particles by weight were investigated: 0%, 5%, 10%, 20%, 30%, 50% and 70%. The phase composition of the enamel coating and sand particles were determined with the X-ray diffraction (XRD) ...
the distribution of extracellular enzyme activities in particle-size fractions of sediments was investigated in a subtropical mangrove ecosystem. five enzymes involved in carbon (c), nitrogen (n), and phosphorus (p) cycling were analyzed in the sand, silt, and clay of sediments. among these fractions, the highest activities of phenol oxidase (pho), β-d glucosidase (glu), and n-acetyl-glucosimin...
The distribution of extracellular enzyme activities in particle-size fractions of sediments was investigated in a subtropical mangrove ecosystem. Five enzymes involved in carbon (C), nitrogen (N), and phosphorus (P) cycling were analyzed in the sand, silt, and clay of sediments. Among these fractions, the highest activities of phenol oxidase (PHO), β-D glucosidase (GLU), and N-acetyl-glucosimin...
Acoustic methods of land mine detection rely on the vibrations of the top plate of the mine in response to sound. For granular soil (e.g., sand), the particle size is expected to influence the mine response. This hypothesis is studied experimentally using a plate loaded with dry sand of various sizes from hundreds of microns to a few millimeters. For low values of sand mass, the plate resonance...
Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand partic...
there are limitations in experimental studies on sand-gravel mixtures due to the small size of testingspecimens. due to this problem, many researchers have worked on prediction of the shear strength of mixture by testingthe sandy fraction of soil alone and developed empirical relationships. most of the previous relationships have beendetermined for low surcharge pressures in which particle brea...
In ostriches, the toes are the only body parts that contact loose sand surfaces. Thus, toe interphalangeal joint motions may play vital biomechanical roles. However, there is little research on ostrich phalangeal joint movements while walking or running on sand. The results from the three-dimensional motion track analysis system Simi Motion show that gait pattern has no significant effect on th...
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