The effect of fine particles on turbulence damping and reduction of flow friction coefficient in ribleted pipes, have been investigated experimentally. Tests have been conducted in a ribleted pipe with hydraulic diameter of 18.6 mm, and 20 stream wise riblets of 1.8 mm depth, along the pipe. Flows of water tap with Reynolds number from 5000 to 30000 were compared with flows containing silt-clay...

Soil texture has been commonly associated with the population density of Heterodera glycines (soybean cyst nematode: SCN), but such an association has been mainly described in terms of textural classes. In this study, multivariate analysis and a generalized linear modeling approach were used to elucidate the quantitative relationship of soil texture with the observed SCN population density redu...

Smectite-rich clay is a major engineered barrier (buffer) in repositories for heat-producing highly radioactive waste. It has the form of densely compacted blocks of clay granules and is only partly water saturated from start. The initial porewater is redistributed by the thermal gradient acting in the buffer and additional water is taken up to give ultimately complete saturation. The compactio...

Adequate clay minerals considerably affect the macroscopic mechanical behavior of water even at concentrations of a few percent. Thus when 2 wt. % laponite clay mineral nanoparticles are added to water, the resulting colloidal suspension after some time takes on the semisolid characteristics of a jellylike material at room temperature. Cold neutron time-of-flight spectroscopy data are in agreem...

Nitrogen exists in soils in many forms and constantly changes from one form to another. The paths that the different forms of nitrogen follow through the ecosystem are collectively called the nitrogen cycle (Figure 1). Understanding how the different pools of nitrogen interact and the processes by which these forms enter and leave the cycle is the subject of continuing study. Nitrogen is found ...

Polymer-based nanocomposites due to their advantages such as corrosion resistance,adequate mechanical properties and low cost are widely used in modern technologies. The increasing application of these nanocomposites, and hence their welding seems unavoidable. In this paper, a novel hottool in friction stir welding process is used for butt welding nanocomposite plates of 5 mm thick containing p...

accurate knowledge of spatial distribution of soil physical and chemical properties is needed for suitable management and proper use of rangelands in masileh plain, qom, iran. in present study, for the spatial modeling of chemical and physical parameters such as sodium (na), calcium (ca), soluble potassium (k), magnesium (mg), electrical conductivity (ec), saturation percentage (sp%), silt, cla...