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Showing 1 to 20 of 29 for “"Hydraulic Pressure"”.
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Effects of transmembrane hydraulic pressure on the performance of forward osmosis membranes, The
… was evaluated at increasing transmembrane hydraulic pressure to address the knowledge gap between accepted laboratory conditions and proposed operating conditions of O and G FO membrane treatment modules; future FO membrane elements will operate with elevated feed pressure to overcome …
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The effect of very high hydraulic pressure on the permeability and salt rejection of reverse osmosis membranes
… membrane can maintain excellent rejection at pressures as high as 172 bar. However, it was also demonstrated that there was a significant drop in permeability at high pressures - likely due to membrane compaction. A simple visco-elastic model was shown to be able to model the overall shape of …
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Hydraulic Mechanisms of Concrete-Tie Rail Seat Deterioration
… and this research investigates three of them: hydraulic pressure cracking, hydro-abrasive erosion, and cavitation erosion. A laboratory test apparatus and procedure were devised to measure the surface water pressure in a laboratory rail seat using tie pads of differing material composition and …
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Electrokinetic and Chemical Aspects of Transport of Chloride Brines Through Compacted Smectite Layers at Elevated Pressures (Electroosmosis, Streaming, Conductivity)
… and of streaming potential. Confining pressure (CP) in these room temperature experiments was 5000 pounds per square inch (psi), differential hydraulic pressure (DHP) across the clay was 2000 psi, and mean hydraulic pressure (MHP) was 2300 psi. These values of CP and MHP are approximate …
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Stability of tunnels in water saturated shale under cyclic stresses: investigation on the coupling between mechanical and seepage characteristics
… simulations, and field monitoring. In-situ hydraulic pressure and geostress tests were conducted, and shale samples were retrieved and processed into standard cylindrical and cubic specimens in the laboratory. Considering the stress and hydrogeological conditions during tunnel excavation, …
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Compressibilidade unidimensional da argila cinza do Rio de Janeiro em Botafogo
… to consolidation caused by reduction of hydraulic pressure of a confined watertable. The equipment utilized, a hydraulic oedometer manufactured by W. Farrance Co. permitted the use of back pressure and the measurement of porewater pressure on the non-drained surface. Comparisons are made …
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The `Electric' Pascal: Absolute and Dynamic Calibration Techniques
This article describes a pressure generation technique that has been applied to the task of calibrating hydraulic pressure transducers. The technique combines principles given by the Lorentz Force and Faraday's Law of Induction to generate a hydrostatic pressure within a cavity. The time history of …
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Organic fouling of desalination membranes
… desalination systems, quantifies the effect of pressure on fouling, and elucidates mechanisms of foulant removal. An experimental apparatus was created to simulate operating conditions in full-scale RO, forward osmosis (FO), and membrane distillation (MD) desalination systems and compare the …
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Internal frost damage in concrete - experimental studies of destruction mechanisms
… different existing destruction theories like the hydraulic pressure theory and the microscopic ice lens theory. The aim was not to build a quantitative model for internal frost destruction.
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Permeability and strength of artificially controlled porous media
Oil well industry has been using hydraulic fracturing to open new channels and thus increase well productivity. Materials known as Proppants are injected into the fracture to keep the channels conductive after the applied hydraulic pressure is removed. But the proppants used to date are often …
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Design, development and validation of a novel mechanical occlusion device for transcervical sterilization
… occlusion of the fallopian tubes were proved by hydraulic pressure testing of the implanted uteri using saline and methylene blue solution. Initial results suggest that the device provides a safe, effective and instant method of permanent female sterilization. Further work is ongoing for in-vivo …
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Artificial Recharge of Groundwater with Recycled Municipal Wastewater in the Pajaro Valley
… used as a seawater intrusion barrier to exert hydraulic pressure on seawater, preventing it from flowing inland. As evidenced by several case studies, clogging can be significant in direct injection wells, but well design and maintenance can effectively address clogging. Surface spreading …
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FORMABILITY OF SHEET-METAL UNDER LATERAL PRESSURE
… made by subjecting circular metal diaphragms to hydraulic pressure on one side. Also, the effects of using different die-shoulder radii on the bulge-forming process, bulge geometry, principal strains, membrane stresses, and formabil- ity are studied. A simple theoretical model is formulated and …
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Investigating the adsorption and transport of water in MFI zeolite pores for water desalination
… zeolite pore network by applying an increasing hydraulic pressure and measuring the change in volumetric displacement. We were able to corroborate the adsorbed pore volume from the TGA experiments and estimated that the pore volume filled was ~72% for a 23 Si/Al ratio MFI zeolite and ~34% for an …
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Bioresorbable Osmotic Pump for Long–term Contraception
… membrane, and the increased internal pressure from the expansion causes the drug formulation to be pushed out through the orifice on the other side. To our best knowledge, bioresorbable osmotic pump implants have never been introduced. The contraceptive drug Levonorgestrel Drug …
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Alternative groundwater resources in North-central Texas for the development of the Barnett Shale gas play
Texas water resources are under pressure due to population growth expected in the coming decades, increasing industrial demands, and frequent periods of drought. With this increasing demand for limited water resources it is important to explore alternative water sources within the State. One of …
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Liposome-Mediated DNA Transfer
… The first method involved the use of high pressure to increase transfection efficiency in cell lines as a potential way to produce transgenics through embryonic stem cells. The second method used artificial insemination with liposome-treated sperm in an effort to produce transgenic animals. …
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Investigation of Reactive Electrokinetic Processes for Permeability Reduction in Hardened Cement Paste
… as a function of competing transport processes (hydraulic pressure flow, electroosmosis, and ionic conduction). Model predictions correlated well with observed cement paste microstructures and permeability measurements. In addition to conducting hydraulic permeability tests, impedance …
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Development of energy efficient membrane distillation systems
… membrane technology which runs at relatively low pressure, which can withstand high salinity feed streams, and which is potentially more resistant to fouling, MD could be used for desalination where reverse osmosis is inadequate. The use of thermal energy, and the ease of construction at small …
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Fracturing processes and induced seismicity due to the hydraulic fracturing of rocks
Hydraulic fracturing is a method used routinely in oil and gas exploitation and in engineered geothermal systems. While used frequently, there are aspects of hydraulic fracturing, such as the propagation of the newly-created fractures and interaction between natural and newly-created fractures, …
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