Glutaminase-asparaginase from Pseudomonas 7A appears to have four subunits with a molecular weight of 36,000 +/- 500 by sedimentation equilibrium in 5.9 M guanidine HCl and 34,000 by amino acid analysis. Analytic sedimentation equilibrium of the native enzyme showed a molecular weight of 140,000 +/- 3,300 with no signs of association or dissociation. Moving boundary and zone sedimentation in bu...

planktonic foraminifera are useful in determining the relative age of the upper cretaceous strata. based on distribution of planktonic foraminifera in kuh-e siah section (212 m thickness), eight biozones have been recognized including dicarinella concavata interval zone (earliest santonian), dicarinella asymetrica total range zone (santonian to earliest campanian), globotruncanita elevata parti...

open-channel junctions have a broad application in civil and environmental engineering. formation of a low-pressure zone with recirculating flow (high sedimentation) accompanied by a high-velocity zone (high erosion) is the most characteristic feature of flow in junctions. a large number of researches have been performed to study the complexity of the flow in junctions in open-channel flows. in...

The study analyses the efficiency of a Sequentional Sedimentation-Biofiltration System (SSBS) built on the Sokolowka river in Lodz (Poland). It was constructed to purify a small urban river whose hydrological regime is dominated by stormwater and meltwater. The SSBS was constructed on a limited area as multi-zone constructed wetlands. The SSBS consists of three zones: sedimentation zone with st...

In order to increase the performance of a primary sedimentation tank (clarifier), it is essential to have a uniform and calm flow field. The use of suitable baffle configurations may help forming favorable flow field and increase the efficiency of the primary sedimentation tank. In order to find the proper position of a baffle in a rectangular primary sedimentation tank, computational investiga...

A small amount of southern bean mosaic virus was contained in a narrow zone after density-gradient centrifugation, but in a much wider zone after centrifugation with a large amount of a second virus. Zone-spreading of a major component by non-ideal sedimentation in density-gradient centrifugation can cause zone spreading of a minor component that the major component overlaps.

Anthropogenic sedimentation has various detrimental effects in many freshwater ecosystems. Sedimentation is most often caused by erosion following deforestation or development of pristine areas that expose the soil surface to precipitation and surface runoff. Accumulation of eroded sediments in the benthic zone of aquatic ecosystems has a variety of adverse effects on the fauna (Cohen et al. 19...

Based upon down core variations in OrMn ratio in sediment and in micronodules, Mn content, organic carbon and abundance of micronodules in two box cores from high and low sedimentation regions of the Bay of Bengal, 0–20 and 0–40 cm levels were identified as ‘‘Mn oxidation zone’’ in the western and the eastern regions of the bay. Despite similarity in bottom water O and organic carbon contents o...

The effect of overpressure on gas hydrate and free gas distribution in marine sediments is studied using a one-dimensional numerical model that couples sedimentation, fluid flow, and gas hydrate formation. Natural gas hydrate systems are often characterized by high sedimentation rates and/or low permeability sediments, which can lead to pore pressure higher than hydrostatic (overpressure). To q...