The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform
Ahmed Abou-shady - One of the best experts on this subject based on the ideXlab platform.
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Reclaiming salt-affected soils using electro-remediation technology: PCPSS evaluation
Electrochimica Acta, 2016Co-Authors: Ahmed Abou-shadyAbstract:Reclaiming salt-affected soil in arid and semi-arid countries is currently considered a substantial challenge because of water supply deficiencies. Traditionally, salts are removed from soil using either continuous or intermittent washing, which consumes considerable amounts of water. Our motivation for this study is to develop a process for decreasing the reclamation period and total amount of water, and improving the sustainability of reclamation. Recently, we have developed a new generation of soil electro-remediation techniques known as the perforated cathode pipe soil electrokinetic remediation (SEKR) system (PCPSS) for heavy metal removal. PCPSS was investigated for reclaiming salt-affected soils collected from the El-Sallam canal region Egypt. In the present study, enhancement of Na+removal was firstly investigated using a Taguchi Approach orthogonal array (L9OA). The results indicated that the influential factors improved Na+removal in the following order: cathode pipe operating time > voltage > cathode gap > Hydrostatic Head; additionally, the vertical removal above the cathode gap was operating time > Hydrostatic Head > voltage > cathode gap. A confirmation experiment demonstrated that Mg2+removal was as high as 41.7% followed by Na+with 23% removal. Ca2+removal was the lowest (6.6%), likely due to the formation of insoluble CaSO4. K+also showed low removal (8.4%), likely because of its comparatively low concentration. The removed cations show the following sequence: Mg2+> Na2+> K+> Ca2+. A large percent of Cl-was removed (53.3%), whereas SO42- showed the lowest removal (5.1%). The accumulative electroosmosis flow was proportional to the voltage followed by operating time, Hydrostatic Head, and cathode gap, respectively.
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New process for ex situ electrokinetic pollutant removal. I: Process evaluation
Journal of Industrial and Engineering Chemistry, 2012Co-Authors: Ahmed Abou-shady, Changsheng PengAbstract:Abstract Soil electrokinetic remediation (SEKR) is a proven technique for treating inorganic, organic, and radionuclide pollutants, particularly in fine-grained soils. The main obstacle to implementing SEKR is the high pH zone adjacent to the cathode surface, which adversely affects electromigration and electroosmosis mechanisms. There have been many attempts to overcome this drawback, but most of the intended solutions are impractical due to excessive cost or the need for chemical additives. We developed a new process for soil electrokinetic treatment in which the cathode is a vertical perforated pipe inserted into the soil. The removals of Pb 2+ and Zn 2+ from kaolinite were evaluated using the Taguchi approach, in which the effects of five four-level parameters (operation time, electrical potential, cathode gap, concentration, and Hydrostatic Head) were analyzed. The perforated cathode pipe SEKR system (PCPSS) was designed to investigate vertical soil electrokinetic remediation, which has not been extensively studied. The obtained results showed that increasing the cathode gap and Hydrostatic Head enhanced electroosmosis role. Satisfactory removal of Zn 2+ (93.9%) was achieved, however the maximum removed Pb 2+ was 42.7%. The removed Pb 2+ and Zn 2+ above the cathode gap was much better than the cathode. The effects of cathode gap, concentration, and Hydrostatic Head did not exhibit any influence on current passing.
A. D. Kirwan - One of the best experts on this subject based on the ideXlab platform.
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The nonlinear dynamics of a small lens
Soviet journal of physical oceanography, 1992Co-Authors: A. D. KirwanAbstract:A theory for lenses whose geometric and internal deformation radii are comparable is developed. By constraining the lenses to be elliptical, it is possible to treat the nonlinear terms in the hydrodynamic equations in a complete fashion. This means that thes terms are balanced exactly by the local, Coriolis, and Hydrostatic Head gradient accelerations. Two examples of the dynamical evolution of such a lens are presented. The first considers the motion in the absence of any external flow. The second examines the dynamical response of the lens to large-scale deformation. The principal conclusion of the study is that the inclusion of the nonlinear terms in the dynamical balance induces fluctuations in the internal wave band of the hydrodynamic fields.
Peng Zhang - One of the best experts on this subject based on the ideXlab platform.
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Influences of Hydrostatic bath pressure, van der Waals pressure, and fountain pressure on the heat transfer in a bath of superfluid helium
Heat Transfer Research, 2020Co-Authors: Ruzhu Wang, Peng ZhangAbstract:Considering the basic heat transfer rules of superfluid helium and the phase diagram of helium, pressure effects on heat transfer to HeII are especially studied. If the bath pressure is less than λ-pressure (Pλ), special peak heat flux density relations are shown to correlate bath pressure, Hydrostatic Head, and modified pressure items (van der Waals pressure and fountain pressure). If the bath pressure is greater than λ-pressure (P > Pλ), a generalized formula of peak flux density of HeIIp bath is shown. © 1999 Scripta Technica, Heat Trans Asian Res, 29(1): 15–21, 2000
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Pressure effect on the heat transfer in bath of superfluid helium
Cryogenics, 1998Co-Authors: Ruzhu Wang, Peng ZhangAbstract:Abstract Considering the basic heat transfer rules of superfluid helium and the phase diagram of helium, pressure effects on heat transfer to HeII are especially studied. If the bath pressure is less than λ -Pressure ( P λ ), special peak heat flux density relations are shown to correlate bath pressure, Hydrostatic Head and modified pressure items (van der Waals pressure and fountain pressure). If the bath pressure is greater than λ -pressure( P>P λ ), a generalized formula of peak flux density of HeIIp bath is shown.
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Pressure effect on the heat transfer in bath of superfluid helium
Proceedings of the Sixteenth International Cryogenic Engineering Conference International Cryogenic Materials Conference, 1997Co-Authors: Ruzhu Wang, Peng Zhang, Jingyi WuAbstract:Publisher Summary Engineering applications of superfluid helium (HeII) has been focused on by cryophysical and cryogenic researcher after the superconducting magnet has been successfully cooled by superfluid helium, several kinds of subcooled superfluid helium cryostat have been successively developed. This chapter discusses the influence of various types of pressures (bath pressure, Hydrostatic Head, Van-derwaals pressure and fountain pressure) on the heat transfer in a bath of HeII. If the bath pressure is less than λ-Pressure (P λ), special peak heat flux density relations are shown to correlate bath pressure, Hydrostatic Head and modified pressure items (Van-der-waals pressure and fountain pressure). If the bath pressure is greater than λ –pressure (P>P λ), a generalized formula of peak flux density of pressurized superfluid (HeIIp) bath is addressed in the chapter.
Ruzhu Wang - One of the best experts on this subject based on the ideXlab platform.
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Influences of Hydrostatic bath pressure, van der Waals pressure, and fountain pressure on the heat transfer in a bath of superfluid helium
Heat Transfer Research, 2020Co-Authors: Ruzhu Wang, Peng ZhangAbstract:Considering the basic heat transfer rules of superfluid helium and the phase diagram of helium, pressure effects on heat transfer to HeII are especially studied. If the bath pressure is less than λ-pressure (Pλ), special peak heat flux density relations are shown to correlate bath pressure, Hydrostatic Head, and modified pressure items (van der Waals pressure and fountain pressure). If the bath pressure is greater than λ-pressure (P > Pλ), a generalized formula of peak flux density of HeIIp bath is shown. © 1999 Scripta Technica, Heat Trans Asian Res, 29(1): 15–21, 2000
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Pressure effect on the heat transfer in bath of superfluid helium
Cryogenics, 1998Co-Authors: Ruzhu Wang, Peng ZhangAbstract:Abstract Considering the basic heat transfer rules of superfluid helium and the phase diagram of helium, pressure effects on heat transfer to HeII are especially studied. If the bath pressure is less than λ -Pressure ( P λ ), special peak heat flux density relations are shown to correlate bath pressure, Hydrostatic Head and modified pressure items (van der Waals pressure and fountain pressure). If the bath pressure is greater than λ -pressure( P>P λ ), a generalized formula of peak flux density of HeIIp bath is shown.
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Pressure effect on the heat transfer in bath of superfluid helium
Proceedings of the Sixteenth International Cryogenic Engineering Conference International Cryogenic Materials Conference, 1997Co-Authors: Ruzhu Wang, Peng Zhang, Jingyi WuAbstract:Publisher Summary Engineering applications of superfluid helium (HeII) has been focused on by cryophysical and cryogenic researcher after the superconducting magnet has been successfully cooled by superfluid helium, several kinds of subcooled superfluid helium cryostat have been successively developed. This chapter discusses the influence of various types of pressures (bath pressure, Hydrostatic Head, Van-derwaals pressure and fountain pressure) on the heat transfer in a bath of HeII. If the bath pressure is less than λ-Pressure (P λ), special peak heat flux density relations are shown to correlate bath pressure, Hydrostatic Head and modified pressure items (Van-der-waals pressure and fountain pressure). If the bath pressure is greater than λ –pressure (P>P λ), a generalized formula of peak flux density of pressurized superfluid (HeIIp) bath is addressed in the chapter.
Tim Biggins - One of the best experts on this subject based on the ideXlab platform.
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Waterproofing Underground Concrete Structures
1990Co-Authors: Tim BigginsAbstract:Abstract : Waterproofing is a relatively impervious membrane, coating, or sealer used in concealed locations to prevent water from entering or passing through either horizontal or vertical building materials. Waterproofing is designed to exclude water even when the water is under a Hydrostatic Head. Waterproofing is often confused with clear water repellants and bituminous dampproofing. Clear water repellants are intended to reduce water penetration into building materials by capillary action. They are normally used on exterior wall surfaces above grade to prevent damage of horizontal concrete by water, sodium chloride or other ice melting chemicals. Some clear water repellants coatings may also prevent soiling and staining and are frequently used on limestone and concrete for that purpose. Clear water repellents will not prevent the passage of water under a Hydrostatic Head of from air pressure. Bituminous dampproofing is a coating that is used to prevent building materials from absorbing moisture that may migrate further into the building structure.
