Surface sediments at Lakes Fryxell, Vanda and Brownworth in the Antarctic Dry Valleys (ADV) were investigated as analogues for the cold, dry environment on Mars. Sediments were sampled from regions surrounding the lakes and from the ice cover on top of the lakes. The ADV sediments were studied using Raman spectra of individual grains and reflectance spectra of bulk particulate samples and compa...

The size distribution, number and biomass of bacteria in intertidal sediments and seawater of Ohmi Bay were investigated by the image analysis and DAPI direct count technique, in March, July and November, 1983. Bacteria with the equivalent spherical diameter between 0. 5 and 0.81am occupied 75-78% of the total populations in sediments. Mean cell volume of bacteria in sediments (0.159um3) was ab...

We used the bacterial test on the cells called Arthrobacter globiformis in order to detect the level of toxins in the sediment of the Lake Skadar. We kept an eye on the influence of the sediments on the activity of the whole of bacterial dehydrogenase (DNA) by the process of the reduction of the oxidoreduction color of the resasurine into the resofurine. We used the organic fraction of the sedi...

Distribution and speciation of mercury (Hg) in the sediments from a tropical estuary (Godavari estuary) was influenced by the changing physico-chemical parameters of the overlying water column. The sediments from the upstream and downstream of the estuary were uncontaminated but the sediments from the middle of the estuary were contaminated by Hg. The concentrations of Hg became considerably le...

Open spaces in epithermal veins of the Bohemia mining district, Oregon, USA, filled with sediments during hydrothermal activity. These sediments consist mainly of chalcedony, rock fragments, and vein quartz fragments. In addition, hematite is deposited during stage three of the vein development. Observed sedimentary features include draping laminae, erosion surfaces, slumping, and graded beddin...

abstract wind erosion of soils and suspended particles in iran is one of the serious environmental and agricultural problems which affect agricultural lands, water reservoirs, irrigation canals, drains and etc. therefore wind erosion control needs attention specially in arid and semi-arid regions. although in recent years, some polymeric materials have been used for improvement of structural st...

The climate change affects the coastal infrastructure including ports. This effect is through changes in tides, waves, wind and erosion. As a result, sedimentation harbours area increases therefore there need for more regular dredging as well adaption to reduce vulnerability. More frequent means higher amount of sediments be disposed or treated. One methods proposed impact high reducing environ...

Factors affecting the transport and retention of Cd, Cr, Cu, Ni, Pb and Zn in acidic groundwaters as they pass through estuarine sediments were investigated using column experiments. Acidic groundwaters caused the rapid dissolution of iron sulfide (AVS) and other iron and manganese phases from sediments that are important for metal binding and buffering. Metal breakthrough to overlying water oc...

Chromium exists in sediments in two oxidation states: Cr(III), which is relatively insoluble and nontoxic, and Cr(VI), which is much more soluble and toxic. Chromium(VI) is thermodynamically unstable in anoxic sediments, and acid-volatile sulfide (AVS) is formed only in anoxic sediments; therefore sediments with measurable AVS concentrations should not contain toxic Cr(VI). If this hypothesis h...