Seasonal variations in pore water and solid phase geochemistry were investigated in urbanized minerotrophic peat sediments located in southwestern Michigan, USA. Sediment pore waters were collected anaerobically, using pore water equilibrators with dialysis membranes (“peepers”) and analyzed for pH, alkalinity, dissolved PO−3 4 , NH + 4 , S −2, SO−2 4 , Fe +3, Fe+2, and Mn+2 at 1–2 cm intervals...

A mathematical model of compaction in sedimentary basins is presented and analyzed. Compaction occurs when accumulating sediments compact under their own weight, expelling pore water in the process. If sedimentation is rapid or the permeability is low, then high pore pressures can result, a phenomenon which is of importance in oil drilling operations. Here we show that one-dimensional compactio...

For enhanced phytoextraction, mobilization of heavy metals (HMs) from the soil solid phase to soil pore water is an important process. A pot incubation experiment mimicking field conditions was conducted to investigate the performance of three soil additives in mobilizing HMs from contaminated paddy soil (Gleyi-Stagnic Anthrosol): the [S, S]-isomer of ethylenediamine disuccinate (EDDS) with app...

Transmembrane lipid translocation (flip-flop) processes are involved in a variety of properties and functions of cell membranes, such as membrane asymmetry and programmed cell death. Yet, flip-flops are one of the least understood dynamical processes in membranes. In this work, we elucidate the molecular mechanism of pore-mediated transmembrane lipid translocation (flip-flop) acquired from exte...

it is proposed to use a single base platform in the persian gulf considering its low depth and more appropriate environmental conditions in comparison to north sea and mexico gulf where this kind of platform is very popular. the pile of platform is responsible for transmission of environmental loads resulted from waves, currents, wind and dead loads to foundation of platform. using sacs 5.3 sof...

A technique of neutron in-plane scattering for studying the structures of peptide pores in membranes is described. Alamethicin in the inserted state was prepared and undeuterated and deuterated dilauroyl phosphatidylcholine (DLPC) hydrated with D2O or H2O. Neutron in-plane scattering showed a strong dependence on deuteration, clearly indicating that water is a part of the high-order structure o...

Soil aggregates include sand/silt/clay, water, ion and organic matter contents combined with natural dry/wet (D/W) cycling alters both the formation and function of intra-aggregate pore continuity, connectivity, dead-end storage volumes, and tortuosity. Surface aggregates in the 0-5 cm depths of most soils experience from 34 to 57 D/W cycles that exceed differences in water contents >10%. Both ...

[1] Contaminant-scavenging colloids are mobilized in the vadose zone during infiltration events, characterized by transient flow regimes. In the research reported here we develop a mathematical model in order to investigate the influences of flow transients on colloid mobilization in unsaturated media. The model solves coupled equations for unsteady pore water flow, colloid release, advective-d...

Because of its roles in human physiology, Aquaporin V (AQP5), a major intrinsic protein, has been a subject of many in vitro studies. In particular, a 2008 experiment produced its crystal structure at 2.0Å resolution, which is in a tetrameric conformation consisting of four protomers. Each protomer forms an amphipathic pore that is fit for water permeation. The tetramer has a pore along its qua...

Hydrophilic polymers alone are not quite efficient in controlling the release of highly water soluble drugs. Hydrophobic Polymer and pore forming agent have been extensively investigated for sustaining the release of drug. They provide several advantages include good stability at varying pH ranges and effectively retards the water soluble drug. In the present study it was a novel approach where...