This paper concerns the study of ripples that occur on windward Barchan dunes from field Najaf governorate, Iraq. These consist mainly sand sediments with variable sizes, including medium, fine, and very fine sands. Quartz represents major light mineral in Dunes sand. The prevailing wind direction area is NW-SE. ripple crest series every pattern are oriented perpendicular to NW-SE direction, wh...

An in situ experimental study of variations of compressional wave speed and attenuation with depth in natural coral sands has been made offshore of Oahu, Hawaii. In situ data were collected at a center frequency of 7.5 kHz. Compressional wave speed averages around 1620 m/s and attenuation ~expressed as Qp , the reciprocal of the quality factor! decreases from 0.04 at the seafloor to 0.01 at 2 m...

In this study, natural bentonite was used as natural clay material and samples were taken from the Kalecik district in Ankara. In this research, bentonite is the subject of an analysis from standpoint of assessing the basic properties of engineered barriers with respect to the buffer material. Bentonite and sand mixtures were prepared for tests. Some of clay minerals give relatively higher hydr...

Halting the spread of organic contaminants in subsurface aquifers is a critical environmental problem. We describe a novel "permeable reactive barrier" that results when organophile-solubilizing properties are conferred on siliceous materials by treating them with a cationic polymer and oppositely charged mixed surfactant micelles. Controlled pore glass, quartz sand, and sea sand were treated w...

In the beneficiation of quartz sand, hydraulic classification is a primary way to obtain production in various size fractions. It essential for plants measure particle sand during classification, time evaluate efficiency. However, traditional manual-screening method consumes labor and time, while particle-size analyzer expensive. Thus, size-detection quartz-sand proposed this paper, which based...