Water Permeability

The minimum tillage soil systems ― paraplow, chisel or rotary grape ― are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for soil natural fertility activation and ...

Gas injection is the second largest enhanced oil recovery process, next only to thermal processes used in heavy oil fields. To increase the extent of the reservoir contacted by the injected gas, the gas is generally injected intermittently with water. This mode of injection, called water-alternating-gas (WAG), is being widely practiced in the oil fields.This experimental study is aimed at

This paper is aimed to evaluate the engineering properties of fly ash-based geopolymer bricks. Four geopolymer brick mixtures were designed with a constant solution-to-binder ratio of 0.40 and various concentrations of sodium hydroxide solution. The engineering properties of fly ash-based geopolymer bricks consisting of compressive strength, unit weight, water absorption, water permeability, and ultrasonic pulse velocity were investigated. The microstructure of fly ash-based geopolymer bricks was also investigated by using the scanning electron microscope (SEM). Test results indicated that the compressive strength, unit weight, and ultrasonic pulse velocity (UPV) of geopolymer bricks increased, while the water absorption and water permeability of geopolymer bricks reduced with increasing NaOH concentration. Moreover, brick samples with high NaOH concentration showed a higher geopolymeric reaction of fly ash than brick samples with low NaOH concentration. All geopolymer brick samples produced in this study showed a good quality with compressive strength of above 10.1 MPa, water absorption of below 9.4%, water permeability of below 1.84 L/m 2 .h, and UPV of above 2500 m/s.

Poly(vinyl butyral) (PVB)/surfactant with high molecular weight (Pluronic F127) blend hollow fiber membranes were prepared via thermally induced phase separation (TIPS) from PVB/Pluronic F127/diluent (PEG200) system. The phase diagram of PVB/PEG200 system was obtained and the addition of Pluronic F127 to this system led to the decrease of the cloud point. In order to know the kinetic property in the

Maghemite iron oxide nanoparticles (γ-Fe 2 O 3) with a size of about 10 nm have been successfully incorporated in mixed matrix reverse osmosis membranes based on interfacial polymerization (IP) of thin film nanocomposite (TFNC) on porous polysulfone supports. TFNC elaborated in this study comprise iron oxide nanoparticles (NPs), with different concentrations varying from 0.1 to 0.9 wt%, dispersed in polyamide host matrix. The performances of the obtained TFNC were evaluated based on the water permeability and salt rejection. Results indicated that the NPs improved membrane performance under optimal NP concentration. By changing the content of the filler, better hydrophilicity was obtained; the contact angle was decreased from 74° to 29°. Also, with initial NaCl concentration of 2000 ppm and under pressure of 225 psi, the permeate water flux increased from 26 to 44 L/m 2 h at NPs concentration of 0.3% with the maintaining of high salt rejection of 98%.

Pervious concrete which is also known as the no-fines, porous, gap-graded, and permeable concrete and enhance porosity concrete has been found to be a reliable storm water management tool. By definition, pervious concrete is a mixture of gravel or granite stone, cement, water, little to no sand (fine aggregate) with or without admixtures. Pervious concrete is traditionally used in Parking areas, areas with high traffic, walk ways in parks and gardens, Residential streets, Pedestrian walkways and Green houses, Basketball and volley ball courts etc. In this study experimental investigation is carried out to study the properties of Pervious Concrete by partial replacing cement with different percentages of GGBS (0%, 20%, 40%, 50%, 60%, and 80%). To achieve optimum concrete mix various trial mixes are done by varying cement, coarse aggregate, water and super plasticizers. Once getting the optimum mix, six mix design are done by replacing cement with GGBS at 0%, 20%, 40%, 50%, 60%, 80 %. The pervious concrete mix is produced by using conventional cementitious materials, aggregates, and water. This concrete is tested for its Fresh properties such as workability and Hardened Properties such as density, void ratio, compressive strength, and water permeability. The most important property of pervious concrete is its water permeability. Currently, there is no standard experimental procedure to determine to this property. A method was therefore developed to determine the water permeability.

Understanding the selectivity of aquaporin water channels will require structural and functional studies of wild-type and modified proteins; however, expression systems have not previously yielded aquaporins in the necessary milligram quantities. Here we report expression of a histidine-tagged form of Escherichia coli aquaporin-Z (AqpZ) in its homologous expression system. 10-His-AqpZ is solubilized and purified to near homogeneity in a single step with a final yield of ∼2.5 mg/l of culture. The histidine tag is removed by trypsin, yielding the native protein with the addition of three N-terminal residues, as confirmed by microsequencing. Sucrose gradient sedimentation analysis showed that the native, solubilized AqpZ protein is a trypsin-resistant tetramer. Unlike other known aquaporins, AqpZ tetramers are not readily dissociated by 1 % SDS at neutral pH. Hydrophilic reducing agents have a limited effect on the stability of the tetramer in 1 % SDS, whereas incubations for more than 24 hours, pH values below 5.6, or exposure to the hydrophobic reducing agent ethanedithiol cause dissociation into monomers. Cys20, but not Cys9, is necessary for the stability of the AqpZ tetramer in SDS. Upon reconstitution into proteoliposomes, AqpZ displays very high osmotic water permeability (pf ⩾ 10 × 10−14 cm3 s−1 subunit−1) and low Arrhenius activation energy (Ea = 3.7 kcal/mol), similar to mammalian aquaporin-1 (AQP1). No permeation by glycerol, urea or sorbitol was detected. Expression of native and modified AqpZ in milligram quantities has permitted biophysical characterization of this remarkably stable aquaporin tetramer, which is being utilized for high-resolution structural studies.