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1
Juh�sz, A. Z. "Water vapor adsorption and capillary reactions of silicates." Colloid & Polymer Science 267, no. 11 (November 1989): 1036–54. http://dx.doi.org/10.1007/bf01410165.
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Comanns, Philipp, Falk J. Esser, Peter H. Kappel, Werner Baumgartner, Jeremy Shaw, and Philip C. Withers. "Adsorption and movement of water by skin of the Australian thorny devil (Agamidae: Moloch horridus )." Royal Society Open Science 4, no. 9 (September 2017): 170591. http://dx.doi.org/10.1098/rsos.170591.
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Moisture-harvesting lizards, such as the Australian thorny devil Moloch horridus , have remarkable adaptations for inhabiting arid regions. Their microstructured skin surface, with channels in between overlapping scales, enables them to collect water by capillarity and passively transport it to the mouth for ingestion. We characterized this capillary water transport for live thorny devils using high-speed video analyses. Comparison with preserved specimens showed that live lizards are required for detailed studies of skin water transport. For thorny devils, there was no directionality in cutaneous water transport (unlike Phrynosoma ) as 7 µl water droplets applied to the skin were transported radially over more than 9.2 mm. We calculated the total capillary volume as 5.76 µl cm −2 (dorsal) and 4.45 µl cm −2 (ventral), which is reduced to 50% filling by the time transportation ceases. Using micro-computed tomography and scanning electron microscopy of shed skin to investigate capillary morphology, we found that the channels are hierarchically structured as a large channel between the scales that is sub-divided by protrusions into smaller sub-capillaries. The large channel quickly absorbs water whereas the sub-capillary structure extends the transport distance by about 39% and potentially reduces the water volume required for drinking. An adapted dynamics function, which closely reflects the channel morphology, includes that ecological role.
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Li, Kewen, and Roland N. Horne. "An Experimental and Analytical Study of Steam/Water Capillary Pressure." SPE Reservoir Evaluation & Engineering 4, no. 06 (December 1, 2001): 477–82. http://dx.doi.org/10.2118/75294-pa.
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Summary Significant mass transfer between the steam and water phases makes it difficult to measure steam/water capillary pressure using routine methods. Because of the difficulties, few experimental data are available. A formula was derived on the basis of the Kelvin equation to calculate steam/water capillary pressure. The water-phase temperatures and pressures measured with a steady-state flow method were used to perform the calculations. The preliminary results of both drainage and imbibition steam/water capillary pressure were obtained. It was confirmed that the lowering of vapor pressure was small, but the capillary pressure was significant for the system studied. This experimental observation is consistent with thermodynamic analysis. Introduction It has often been assumed in steam numerical simulators that steam/water flow in porous media can be represented as gas (air or nitrogen)/water flow. In recent years, attention has been paid to the measurements of steam/water relative permeability.1–6 Horne et al.2 found that there were significant differences between nitrogen/water and steam/water relative permeabilities. Accordingly, there may also be significant differences between nitrogen/water and steam/water capillary pressures. To compare the two, reliable experimental data for steam/water capillary pressure are required. However, there have been few direct measurements of steam/water capillary pressure from steam/water flow experiments. Less attention has been paid to the measurements of steam/water capillary pressure, even though capillary pressure is of equal significance to relative permeability and plays an important role in controlling fluid distributions and recoveries in petroleum and geothermal reservoirs. Tsypkin and Calore7 developed a mathematical model of steam/water phase transition. They found that steam/water capillary pressure could play a stabilizing role for the vaporization front, causing a sharp zone to develop. Urmeneta et al.8 also studied the role of capillary forces in fractured reservoirs and found that capillary pressure tended to keep the vapor phase in the fracture and the liquid phase in the matrix. Using the adsorption data of Horne et al.9 for rock samples from The Geysers geothermal field, Sta. Maria and Pingol10 inferred the values of steam/water capillary pressure. They found that the steam/water capillary pressure ranged from 0 to 86,000 psi. Persoff and Hulen11 also inferred the capillary pressure from adsorption data of The Geysers rock samples and found that the steam/water capillary pressure ranged from 0 to approximately 28,000 psi. The graywacke core samples used by Persoff and Hulen11 were similar to those used by Sta. Maria and Pingol.10 The porosity was approximately 2%, and the permeability was in the nanodarcy (nd) range. The adsorption/desorption tests that have been used to infer steam/water capillary pressure are static processes in which there is no steam/water flow. In actual petroleum and geothermal reservoirs, however, capillary pressure plays an important role while steam and water flow simultaneously through the rocks. Hence, the process governing an adsorption test may not represent the mechanisms under actual fluid-flow conditions in those reservoirs. The steam/water capillary pressures from adsorption data may or may not be the same as those measured with a dynamic method in which steam and water are flowing. Very strict sealing requirements must be achieved for long periods of time during the adsorption tests, which is very difficult, especially at high temperatures. These disadvantages may be overcome by using a steady-state flow method. The main purpose of this paper was to develop a method to calculate steam/water capillary pressure using data from the experiments of steady-state steam/water flow. An X-ray computerized tomography (CT) technique was used to measure the water saturation and its distribution in the core sample. The effect of temperature on CT values used to calculate the water saturations was studied experimentally. Method Capillary Pressure. Using the Kelvin equation, steam/water capillary pressure can be calculated from the experimental data of liquid-phase pressure, temperature, and related parameters. The procedure is described in this section. The relative pressure (pv/p0) is used to characterize the capillary condensation on curved surfaces. Kelvin established the relationship between the relative pressure and the curvature of the interface, along with other properties of the fluid and the substrate. In a circular capillary tube with a radius of r, the relative pressure can be calculated using the Kelvin equation as follows:Equation 1 where p0=the vapor pressure when the vapor/liquid interface is flat; pv=the vapor pressure in a capillary tube of radius r when the vapor/liquid interface is curved; s=the interfacial tension and ?=the contact angle measured through the liquid phase; R=the gas constant; T=the absolute temperature; Mw=the molecular weight of liquid; and ?w=the density of liquid. The Kelvin equation assumes that (1) all adsorption is caused only by capillary condensation, (2) adsorbate density is equal to bulk liquid density, and (3) the validity is unimpaired at low values of r. The capillary pressure, Pc, in a circular capillary tube is also determined by the interface curvature and fluid and substrate properties and can be calculated asEquation 2 Combining Eqs. 1 and 2,Equation 3 Capillary pressure is defined as the pressure difference between the nonwetting and the wetting phases and is expressed as follows:Equation 4
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Zhang, Jiwen, Qingyi Mu, Hongjian Liao, and Jie Cao. "An unfrozen water retention curve for capturing soil density and specific surface effects." E3S Web of Conferences 195 (2020): 02018. http://dx.doi.org/10.1051/e3sconf/202019502018.
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Unfrozen water retention curve (UWRC) defines the relationship between temperature and unfrozen water content in frozen soils. Although many models have been proposed for the UWRC, these existing models cannot predict UWRC well over a wide temperatures range. In this study, a new UWRC model is proposed with explicit considerations of both capillarity and adsorption. In this model, capillarity is considered dominating when the freezing of soil pore water at higher temperatures (above -2oC), whereas the effects of adsorption pronounce at temperatures below -2oC. Moreover, effects of void ratio on the freezing of capillary water are incorporated. The proposed model was applied to predict UWRCs of silt and clay at different initial void ratios over a wide temperature range (from -50 to 0oC). Predicted results by this new model are compared with predictions by three well-known existing models. The new model can capture the density effects on UWRC. Moreover, the new model can predict better UWRC over a wide temperature range since it explicitly considers both effects of capillarity and adsorption.
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Liu, Xiang Jun, Yun Fei Shi, Mohammad Ali Kalbassi, Richard Underwood, and Ying Shu Liu. "Water vapor adsorption isotherm expressions based on capillary condensation." Separation and Purification Technology 116 (September 2013): 95–100. http://dx.doi.org/10.1016/j.seppur.2013.05.020.
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Orfanus, Tomas, Abdel-Monem Mohamed Amer, Grzegorz Jozefaciuk, Emil Fulajtar, and Anežka Čelková. "Water vapour adsorption on water repellent sandy soils." Journal of Hydrology and Hydromechanics 65, no. 4 (December 20, 2017): 395–401. http://dx.doi.org/10.1515/johh-2017-0030.
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AbstractSoil sorptivity is considered a key parameter describing early stages of water (rain) infiltration into a relatively dry soil and it is related to build-up complexity of the capillary system and soil wettability (contact angles of soil pore walls). During the last decade an increasing water repellency of sandy soils under pine forest and grassland vegetation has been frequently observed at Mlaky II location in SW Slovakia. The dry seasons result in uneven wetting of soil and up to hundredfold decrease in soil sorptivity in these vegetated soil as compared to reference sandy material, which was out of the reach of ambient vegetation and therefore readily wettable. As far as water binding to low moisture soils is governed by adsorption processes, we hypothesized that soil water repellency detected by water drop penetration test and by index of water repellency should also influence the water vapour adsorption parameters (monolayer water content, Wm, specific surface area, A, maximum adsorption water, Wa, maximum hygroscopic water MH, fractal dimension, DS and adsorption energies, Ea) derived from BET model of adsorption isotherms. We found however, that the connection of these parameters to water repellency level is difficult to interpret; nevertheless the centres with higher adsorption energy prevailed evidently in wettable materials. The water repellent forest and grassland soils reached less than 80% of the adsorption energy measured on wettable reference material. To get more conclusive results, which would not be influenced by small but still present variability of field materials, commercially available homogeneous siliceous sand was artificially hydrophobized and studied in the same way, as were the field materials. This extremely water repellent material had two-times lower surface area, very low fractal dimension (close to 2) and substantially lower adsorption energy as compared to the same siliceous sand when not hydrophobized.
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Tokay, Begum, John L. Falconer, and Richard D. Noble. "Alcohol and water adsorption and capillary condensation in MFI zeolite membranes." Journal of Membrane Science 334, no. 1-2 (May 2009): 23–29. http://dx.doi.org/10.1016/j.memsci.2009.02.010.
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Thamm, H., H. Stach, E. Jahn, and B. Fahlke. "Calorimetric Investigation of the Adsorption Properties of Microporous Aluminophosphate AlPO4−5." Adsorption Science & Technology 3, no. 4 (December 1986): 217–20. http://dx.doi.org/10.1177/026361748600300401.
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Differential heats of adsorption have been measured calorimetrically for benzene and n-hexane on AlPO4-5. Adsorption isotherms have been determined for benzene, n-hexane and H2O. The heat of adsorption for benzene on AlPO4-5 was found to be less than the heat of adsorption for n-hexane. Isotherms of all adsorbates investigated exhibited hysteresis loops. The hydrophilicity of AlPO4-5 is explained by capillary condensation and/or coordinately bonded water.
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Pham, Tien Duc, Thi Trang Do, Van Lau Ha, Thi Hai Yen Doan, Thi Anh Huong Nguyen, Thanh Duc Mai, Motoyoshi Kobayashi, and Yasuhisa Adachi. "Adsorptive removal of ammonium ion from aqueous solution using surfactant-modified alumina." Environmental Chemistry 14, no. 5 (2017): 327. http://dx.doi.org/10.1071/en17102.
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Environmental contextAmmonium ion, an inorganic pollutant in agricultural land, can induce eutrophication, impacting on water quality. We investigate the adsorption of ammonium ion on surfactant-modified alumina and demonstrate highly efficient removal of ammonium ions by the alumina from two agricultural water samples. Adsorption mechanisms are also proposed based on adsorption isotherms, surface modification and the change in surface charge. AbstractThe adsorptive removal of ammonium ions (NH4+) from aqueous solution using surfactant-modified alumina (SMA) was investigated. The optimum NH4+ adsorption removal conditions on SMA were systematically studied and found to be pH 4, contact time 180min, adsorbent dosage 30mgmL–1 and ionic strength 1mM NaCl. The equilibrium concentration of NH4+ was measured by capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D) and spectrophotometry. Surface modification of α-Al2O3 with the anionic surfactant sodium dodecyl sulfate (SDS) at high salt concentration induced a significant increase of removal efficiency. The change in surface charge and surface modification of α-Al2O3 by pre-adsorption of SDS and subsequent adsorption of NH4+ were evaluated by zeta potential measurements and Fourier-transform infrared spectroscopy. Under optimum adsorption conditions, NH4+ removal from two agricultural water samples achieved very high removal efficiencies of 99.5 and 96.5%. The adsorption of NH4+ onto SMA increases with decreasing NaCl concentration because desorption of SDS from the α-Al2O3 surface is minimised. Experimental results of NH4+–SMA adsorption isotherms at different ionic strengths can be represented well by a two-step adsorption model. Based on adsorption isotherms, surface charge effect and surface modification, we suggest that the adsorption mechanism of NH4+ onto SMA was mainly electrostatic attraction between cationic NH4+ and the negatively charged SMA surface.
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Đức, Ngô Minh. "SYNTHESIS Mg-Al HYDROTALCITE FOR ADSORPTION OF Pb2+ IN WATER." Hue University Journal of Science: Natural Science 127, no. 1A (April 2, 2018): 15. http://dx.doi.org/10.26459/hueuni-jns.v127i1a.4123.
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Hydrotalcite was synthesized using the co-precipitation method with the Mg/Al molar ratio of 3.0 and then calcined at 450 °C, for 5 h. The obtained solid was characterized by XRD, BET. As seen from results of physical characterization, the synthesized Hydrotalcite material owns large surface area of 309.3 m<sup>2</sup>/g, mean capillary diameter of 11.52 nm. Hydrotalcite application as adsorbent of heavy metal ions. The results of adsorption experiment for Pb<sup>2+</sup> in water showed that the absorption equilibrium was attained after 90 minutes at pH = 5 with maximum adsorption loading capacity of 144.93 mg/g. The synthesized adsorbent could be regenerated with HNO<sub>3</sub> (1M) solution
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Petrova, Zhanna, and Kateryna Samoilenko. "Adsorption Properties of Combined Vegetable Powders." Energy Engineering and Control Systems 7, no. 1 (2021): 38–47. http://dx.doi.org/10.23939/jeecs2021.01.038.
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Equilibrium moisture of combined vegetable powders obtained from vegetable raw materials is one of the main technological properties and it is important. Because the final moisture content and energy costs for the dehydration process depend on this indicator. To determine the equilibrium humidity of the samples of combined powders, depending on the relative humidity, the tensometric (static) method of Van Bamelen was used. As a result of researches, kinetic curves of adsorption of water vapor of mono- and combined vegetable powders, which were compared among themselves, were received. Comparison of adsorption isotherms, despite the same nature of these isotherms, show that these materials are capillary-porous colloidal bodies and have the same forms of moisture binding (adsorption, capillary and osmotic) and at the same time differ significantly from each other by equilibrium humidity. When storing composite powders in order to preserve their technological properties, it is recommended to maintain the following conditions in the room: humidity not more than 60 % at the temperature of 20 - 25 ºC and to pack hermetically.
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Maleksaeedi, Emad, and Mathieu Nuth. "Evaluation of capillary water retention effects on the development of the suction stress characteristic curve." Canadian Geotechnical Journal 57, no. 10 (October 2020): 1439–52. http://dx.doi.org/10.1139/cgj-2019-0326.
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The suction stress characteristic framework is a practical approach for relating the suction and the water-filled pore volume to the stress state of unsaturated soils. It predicts the effective stress by developing the suction stress characteristic curve from the soil-water retention curve. In this framework, the effective degree of saturation is usually calculated by the empirical water retention model of van Genuchten (published in 1980). In this paper, the use of a generalized soil-water retention model proposed by Lu in 2016, which differentiates the role of capillary and adsorption mechanisms, in the suction stress characteristic framework is studied. A redefinition of the effective degree of saturation is suggested, by choosing the retention state where capillarity approaches zero instead of the residual retention state. The validity of this assumption is examined using experimental data obtained by unsaturated shear strength and retention tests and datasets collected from the literature. The proposed definition is applicable for a variety of soils where capillarity is the dominant mechanism in producing suction stress within the range of suction 0–1500 kPa. In addition, it is observed that the generalized soil-water retention model presents a more realistic prediction of unsaturated shear strength compared with empirical water retention models.
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Shogenov, Yu Kh, A. Yu Izmailov, and Yu M. Romanovsky. "Adsorption laser meter of water transport velocity in capillary systems of a plant." Russian Agricultural Sciences 42, no. 5 (September 2016): 343–47. http://dx.doi.org/10.3103/s1068367416050232.
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Kazner, C., J. Meier, T. Wintgens, and T. Melin. "Capillary nanofiltration coupled with powdered activated carbon adsorption for high quality water reuse." Water Science and Technology 60, no. 1 (July 1, 2009): 251–59. http://dx.doi.org/10.2166/wst.2009.350.
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Direct capillary nanofiltration was tested for reclamation of tertiary effluent from a municipal wastewater treatment plant. This process can be regarded as a promising treatment alternative for high quality water reuse applications when combined with powdered activated carbon for enhanced removal of organic compounds. The nanofiltration was operated at flux levels between 20 and 25 L/(m2 h) at a transmembrane pressure difference of 2–3 bar for approximately 4,000 operating hours. The study was conducted with PAC doses in the range from 0 to 50 mg/L. The plant removal for DOC ranged from 88–98%. The sulfate retention of the membrane filtration process was between 87 and 96%. The process provided a consistently high permeate quality with respect to organic and inorganic key parameters.
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Wang, Yanbin, Shayandev Sinha, Parth Rakesh Desai, Haoyuan Jing, and Siddhartha Das. "Ion at Air–Water Interface Enhances Capillary Wave Fluctuations: Energetics of Ion Adsorption." Journal of the American Chemical Society 140, no. 40 (September 17, 2018): 12853–61. http://dx.doi.org/10.1021/jacs.8b06205.
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Yue, Jiwei, Zhaofeng Wang, and Jinsheng Chen. "Dynamic response characteristics of water and methane during isobaric imbibition process in remolded coal containing methane." Energy Exploration & Exploitation 37, no. 1 (September 13, 2018): 83–101. http://dx.doi.org/10.1177/0144598718798083.
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Addition of water to the coal is actually an isobaric imbibition process. To study the dynamic response characteristics of water and methane, the isobaric imbibition process was stimulated by a self-designed experimental device which can eliminate the reabsorbing phenomenon. The results indicate that adding water can displace absorbed gas. The displacement mechanism is attributed to the capillary effect and competitive adsorption during isobaric imbibition process. A competitive adsorption phenomenon exists between gas molecules and water molecules. Since oxygen-containing functional groups in coal and the hydrogen bond of water, water can easily occupy high-energy sites and only the low-energy sites are available for methane. The imbibition quantity increases with increasing water content or adsorption equilibrium pressure. Moreover, the imbibition quantity would reach a maximum value. The relationship between water content and maximum imbibition quantity or the maximum imbibition rate can be described by a Langmuir function under the same adsorption equilibrium pressure. The maximum imbibition quantity increases with increasing adsorption equilibrium pressure under the same water content, which also can be described by a Langmuir function. However, the maximum imbibition rate decreases with increasing adsorption equilibrium pressures under the same water content, which can be described by an exponential function. Compared to the adsorption equilibrium pressure, the water content has a greater effect on the imbibition quantity and imbibition rate. This study revealed the mechanisms of the dynamic response characteristics of water and methane during isobaric imbibition process based on the transformation form of Hagen–Poiseuille equation, adsorption force of coal and gas and adsorption force of coal and water, which can provide a new method to control gas in deep coal seams.
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Davlyud, D. N., P. D. Vorobiev, Yu V. Lipai, E. V. Vorobieva, S. V. Bucha, and A. R. Chernikova. "Hydrodynamic and adsorption properties of anionic acrylamide copolymers in water-salt media." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 55, no. 4 (December 6, 2019): 455–63. http://dx.doi.org/10.29235/1561-8331-2019-55-4-455-463.
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Rheological properties and concentration cross-overs of anionic acrylamide copolymers in saline solutions (potassium chloride) were investigated by using capillary viscometer method. Area of non-overlapping coils between the crossover concentration and the concentration of fluctuation mesh formation was determined; it was shown that with increase of salt concentration this area practically disappears, i.e. mass transfer mechanism changes near the crossover concentration. It was shown that at low concentrations of potassium chloride increasing the content of ionic groups of macromolecules leads to reduction in the crossover concentration and increase in the effective volume. It is found that the kaolin adsorption capacity decreases when polymers are adsorbed from saline solution, and the adsorption constant is significantly higher in the presence of salt than in water.
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Zhang, Yue, Tong Jiang, Li Han, Qi Dong Li, Tai Li Sun, and Xi Chuan Zhang. "Investigations of Tool Wear with Water Vapor as Coolant and Lubricant in Green Cutting." Advanced Materials Research 317-319 (August 2011): 556–59. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.556.
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Green cutting is one of the developing tends in the industry field. Water vapor can be introduced in metal cutting as coolant and lubricant due to its pollution-free, generating easily and unneeded disposal. Therefore, a special generating system is developed to produce suitable water vapor, and a simulation to the velocity of water vapor jet flow is presented. Then tool wear was investigated and a new capillary model is proposed, based on the experimental results. According to the boundary-layer theory, the kinetics equations of flow were solute. The velocity and flux of molecule are presented. In the capillary, the adsorption of tool-chip interface results in boundary lubricating film; the conical shape of capillary limits the depth of coolant and lubricant penetrating; and the negative press is the motility for coolant and lubricant penetrating. The study results show water vapor can decrease tool wear about 10% times and 20% comparing to cutting fluids and dry cutting, and water vapor could be a potential solution of green cutting.
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Chandler, Neil, John Palson, and Todd Burns. "Capillary rise experiment to assess effectiveness of an enzyme soil stabilizer." Canadian Geotechnical Journal 54, no. 10 (October 2017): 1509–17. http://dx.doi.org/10.1139/cgj-2016-0511.
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An experimental program to assess of the attributes of an enzyme soil stabilizer is described. The focus of the program was two 1 year capillary rise experiments designed to test the influence of the soil additive on the soil’s adsorption of water. The enzyme additive is typically applied to marginal clay-based soils to improve the performance of road subgrades. The study investigated the potential increase in shear strength and the reduction in swelling. The two long-term soil column tests were conducted to measure water absorption due to capillary rise for soil specimens with, and without, enzyme treatment. The test results demonstrated that the addition of the enzyme soil additive had the effect of reducing water retained in the pore spaces of a partially saturated soil. The soil treated with the enzyme additive absorbed a lower quantity of water in the capillary rise test, and at a slower rate of absorption. The results from a concurrent suite of tests suggested that partially saturated clay having lower moisture content was linked to an increase in shear strength.
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Loglio, Giuseppe, Volodymyr Kovalchuk, Alexey Bykov, Michele Ferrari, Jürgen Krägel, Libero Liggieri, Reinhard Miller, et al. "Dynamic Properties of Mixed Cationic/Nonionic Adsorbed Layers at the N-Hexane/Water Interface: Capillary Pressure Experiments Under Low Gravity Conditions." Colloids and Interfaces 2, no. 4 (November 2, 2018): 53. http://dx.doi.org/10.3390/colloids2040053.
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Capillary pressure experiments are performed in microgravity conditions on board the International Space Station to quantify the dynamic interfacial behavior of mixed adsorption layers of TTAB and C13DMPO at the water/hexane interface. While the non-ionic surfactant C13DMPO is soluble in both bulk phases, water and hexane, the cationic surfactant TTAB is only soluble in the aqueous phase. The interfacial layer is thus formed by TTAB molecules adsorbing from the aqueous phase while the C13DMPO molecules adsorb from the aqueous phase, and transfer partially into the hexane phase until both the equilibrium of adsorption and the distribution between the two adjacent liquid phases is established. The experimental constrains as well as all possible influencing parameters, such as interfacial and bulk phase compressibility, interfacial curvature, calibration of pressure and absolute geometry size, are discussed in detail. The experimental results in terms of the dilational interfacial viscoelasticity of the mixed adsorption layers in a wide range of oscillation frequencies show that the existing theoretical background had to be extended in order to consider the effect of transfer of the non-ionic surfactant across the interface, and the curvature of the water/hexane interface. A good qualitative agreement between theory and experiment was obtained, however, for a quantitative comparison, additional accurate information on the adsorption isotherms and diffusion coefficients of the two studied surfactants in water and hexane, alone and in a mixed system, are required.
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Papavasilopoulos, E. N., and D. H. Bache. "On the role of aluminium hydroxide in the conditioning of an alum sludge." Water Science and Technology 38, no. 2 (July 1, 1998): 33–40. http://dx.doi.org/10.2166/wst.1998.0097.
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This study dwells on the optimum dosage of a nonionic polymer during the conditioning of an alum sludge arising from the treatment of a coloured, upland water. Dewaterability was investigated through Capillary Suction Time (CST) and Specific Resistance to Filtration (SRF) tests, together with viscosity measurements on the liquid phase of sludge. The optimum dose associated with CST and SRF was 1.5 kg/T while for the case of viscosity behaviour it was 2.0 kg/T. From polymer adsorption studies on the sludge, it was shown that the optimum doses associated with the viscosity measurements were linked to a dose at which the adsorption capacity reached a saturation value (1.8 kg/T). The SRF and CST optima were found to correspond to a state of 70-85% of the saturation coverage. Parallel adsorption tests on alum sludge and pure precipitate showed that polymer adsorption on the precipitate was the prime determinant of the adsorption characteristics of the sludge and suggested that the optimum dose was linked to the mass of precipitate present in the sludge.
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Maris, Christophe, Alain Laplanche, Jean Morvan, and Marianne Bloquel. "Development of a Packed Precolumn for Capillary Gas Chromatographic Analysis of Amines in Acidic Aqueous Solution." Water Science and Technology 40, no. 6 (September 1, 1999): 141–48. http://dx.doi.org/10.2166/wst.1999.0283.
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This paper describes an optimization of the analysis of amines in aqueous solution. Direct injection of the acidic sample (HCl 0.12 N) is performed by the coupling of packed precolumn with a capillary column. The basic support efficiently traps residual vapors of hydrochloric acid and water at the injection time; the capillary chromatographic performance is maintained. The precolumn coupling with PoraPLOT Amines capillary column enables a separation and quantification of the lower volatile aliphatic amines (methylamine, dimethylamine, trimethylamine and ethylamine). The ammonia addition to the solution (200 ppm NH3) reduces amine adsorption in the column. The analysis repeatability is about 5% for a 50μM amine mixture and 21% for the quantification limit of 0.5 μM with a sensitive and specific nitrogen phosphor detector. The precolumn avoids using split injection (sensitivity increased). Other nitrogen compounds can be analyzed by this system: aromatic amines (aniline) and unsaturated nitrogen heterocycles (pyridine). This new technique increases the chromatographic performances in comparison with usual methods; its automation is possible.
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Wesołowska, Maria, and Anna Kaczmarek. "The Effect of Modifications on Humidity Parameters of Cement Mortar." Materials Science Forum 865 (August 2016): 178–82. http://dx.doi.org/10.4028/www.scientific.net/msf.865.178.
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Current wall constructions utilize cement mortars, the properties of which have been modified with introducing lime or plasticizers. The complex structure of these mortars as well as their very large inner area results in large differences in capillary moisture transport. Macroscopic studies do not allow to accurately predict the mortar behaviour in contact with water. Capillary rise as well as drying and freezing of water are dependent on the size and the layout of pores. The biggest adsorption capacity is featured by micropores. Moisture transport takes place in mesoporous material, and moisture adsorption takes place on the surface of such materials. Macropores mainly act as a transport medium and carry moisture to mesoporous material and micropores. In terms of mesoporous material and macropores mercury porosimetry is more suitable. Mortar structure plays an important role in the moisture transport. Mortar additives, that have been introduced in the form of lime and plasticizers, modify the distribution and size of pores. Porosimetric study results concerning selected mortars have been presented in this article. The structure changes resulting from the introduction additives to mortars have been analyzed and the impact on humidity of such mortars has been defined.
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Shakeel, Mariam, Aida Samanova, Peyman Pourafshary, and Muhammad Rehan Hashmet. "Capillary Desaturation Tendency of Hybrid Engineered Water-Based Chemical Enhanced Oil Recovery Methods." Energies 14, no. 14 (July 20, 2021): 4368. http://dx.doi.org/10.3390/en14144368.
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Several studies have shown the synergetic benefits of combining various chemical enhanced oil recovery (CEOR) methods with engineered waterflooding (EWF) in both sandstones and carbonate formations. This paper compares the capillary desaturation tendency of various hybrid combinations of engineered water (EW) and CEOR methods with their conventional counterparts. Several coreflood experiments were conducted, including EW-surfactant flooding (EWSF), EW-polymer flooding (EWPF), EW-alkali-surfactant flooding (EWASF), EW-surfactant-polymer flooding (EWSPF), and EW-alkali-surfactant-polymer flooding (EWASP). Capillary numbers (Nc) and corresponding residual oil saturation (Sor) for each scenario are compared with capillary desaturation curves (CDC) of conventional CEOR methods from the literature. The results indicate that hybrid EW–CEOR methods have higher capillary desaturation tendency compared to conventional methods. The capillary numbers obtained by standalone polymer flooding (PF) are usually in the range from 10−6 to 10−5, which are not sufficient to cause a significant reduction in Sor. However, the hybrid EW-polymer flooding approach considerably reduced the Sor for the same Nc values, proving the effectiveness of the investigated method. The hybrid EWASP flooding caused the highest reduction in Sor (23%) against Nc values of 8 × 10−2, while conventional ASP flooding reduced the Sor for relatively higher Nc values (3 × 10−3 to 8 × 10−1). Overall, the hybrid methods are 30–70% more efficient in terms of recovering residual oil, compared to standalone EWF and CEOR methods. This can be attributed to the combination of different mechanisms such as wettability modification by EW, ultralow interfacial tension by alkali and surfactant, reduced surfactant adsorption by alkali addition, and favorable mobility ratio by polymer. Based on the promising results, these hybrid techniques can be effectively implemented to carbonate formations with harsh reservoir conditions such as high salinity and high temperature.
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Boudot, Mickael, Hervé Elettro, and David Grosso. "Converting Water Adsorption and Capillary Condensation in Usable Forces with Simple Porous Inorganic Thin Films." ACS Nano 10, no. 11 (November 3, 2016): 10031–40. http://dx.doi.org/10.1021/acsnano.6b04648.
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Lanzerath, Franz, Jan Seiler, Meltem Erdogan, Heike Schreiber, Matthias Steinhilber, and André Bardow. "The impact of filling level resolved: Capillary-assisted evaporation of water for adsorption heat pumps." Applied Thermal Engineering 102 (June 2016): 513–19. http://dx.doi.org/10.1016/j.applthermaleng.2016.03.052.
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Simeski, Filip, Arnout M. P. Boelens, and Matthias Ihme. "Modeling Adsorption in Silica Pores via Minkowski Functionals and Molecular Electrostatic Moments." Energies 13, no. 22 (November 16, 2020): 5976. http://dx.doi.org/10.3390/en13225976.
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Capillary condensation phenomena are important in various technological and environmental processes. Using molecular simulations, we study the confined phase behavior of fluids relevant to carbon sequestration and shale gas production. As a first step toward translating information from the molecular to the pore scale, we express the thermodynamic potential and excess adsorption of methane, nitrogen, carbon dioxide, and water in terms of the pore’s geometric properties via Minkowski functionals. This mathematical reconstruction agrees very well with molecular simulations data. Our results show that the fluid molecular electrostatic moments are positively correlated with the number of adsorption layers in the pore. Moreover, stronger electrostatic moments lead to adsorption at lower pressures. These findings can be applied to improve pore-scale thermodynamic and transport models.
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Szewczyk, Dawid, Rune M. Holt, and Andreas Bauer. "The impact of saturation on seismic dispersion in shales — Laboratory measurements." GEOPHYSICS 83, no. 1 (January 1, 2018): MR15—MR34. http://dx.doi.org/10.1190/geo2017-0169.1.
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Previous studies found a significant increase of acoustic velocities between seismic and ultrasonic frequencies (seismic dispersion) for shales, which would have to be taken into account when comparing seismic or sonic field data with ultrasonic measurements in the laboratory. We have executed a series of experiments performed with a partially saturated Mancos shale and a Pierre shale I in which the influence of water saturation on acoustic velocities and seismic dispersion was investigated. The experiments were carried out in a triaxial setup allowing for combined measurements of quasistatic rock deformation, ultrasonic velocities, and dynamic elastic stiffness at seismic frequencies under deviatoric stresses. Prior to testing, the rock samples were preconditioned in desiccators at different relative humidities. For both shale types, we present and analyze the experimental results that demonstrate strong saturation and frequency dependence of dynamic Young’s moduli, Poisson’s ratios, and Thomsen’s anisotropy parameters, as well as P- and S-wave velocities at seismic and ultrasonic frequencies. The observed effects can be attributed to water adsorption and capillary pressure that are functions of several factors including water saturation. Water adsorption results in a reduction of surface energy and grain-contact stiffness. The capillary pressure affects the effective stress and possibly also the effective pore-fluid modulus, which may be approximated by Brie’s empirical model. Reasonable fits to the low-frequency seismic data are obtained by accounting for these two effects and applying the anisotropic Gassmann model. The strong increase in dispersion with increasing water saturation is attributed to local flow involving adsorbed (bound) water, but a quantitative description is yet to be provided.
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Anzivino, Carmine, Fuqiang Chang, Giuseppe Soligno, René van Roij, Willem K. Kegel, and Marjolein Dijkstra. "Equilibrium configurations and capillary interactions of Janus dumbbells and spherocylinders at fluid–fluid interfaces." Soft Matter 15, no. 12 (2019): 2638–47. http://dx.doi.org/10.1039/c8sm02361a.
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We numerically investigate the adsorption of a variety of Janus particles (dumbbells, elongated dumbbells and spherocylinders) at a fluid–fluid interface by using a numerical method that takes into account the interfacial deformations. We also experimentally synthesize micrometer–sized charged Janus dumbbells and let them adsorb at a water–decane interface. We find a good agreement between numerical and experimental results.
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Erko, M., D. Wallacher, A. Brandt, and O. Paris. "In-situsmall-angle neutron scattering study of pore filling and pore emptying in ordered mesoporous silica." Journal of Applied Crystallography 43, no. 1 (December 1, 2009): 1–7. http://dx.doi.org/10.1107/s0021889809044112.
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The capillary condensation and capillary emptying of water and perfluoropentane in ordered mesoporous SBA-15 silica is studied byin-situsmall-angle neutron scattering (SANS). The SANS data can be perfectly described by a simple analytical model for spatially random pore filling (Laue scattering) for the entire range of pore-filling fractions. From this it is concluded that recently proposed pore correlations due to elastic interactions between neighbouring pores upon capillary condensation do not play a role in this system. The pores fill randomly according to their size distribution, in perfect agreement with the classical Kelvin equation. The relation between the overall pore-filling fraction as determined from the volumetric sorption isotherm, and the fraction of completely filled pores as obtained from the fit of the SANS data, allows conclusions to be drawn about the thermodynamic metastability of the adsorption process.
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Barbour, S. Lee. "Nineteenth Canadian Geotechnical Colloquium: The soil-water characteristic curve: a historical perspective." Canadian Geotechnical Journal 35, no. 5 (October 1, 1998): 873–94. http://dx.doi.org/10.1139/t98-040.
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The constitutive relationship between water content or degree of saturation and suction is called the soil-water characteristic curve. The soil-water characteristic curve provides a conceptual framework in which the behavior of unsaturated soils can be understood. A historical review illustrates how the work of early researchers in soil science and geotechnical engineering laid the foundation for our current understanding of this relationship. Key elements of these early studies were a conceptual understanding of the soil-water characteristic curve as a relationship between the mass or volume of water stored within the soil and the energy in the water phase. It was on the basis of this conceptual model that current methods of measuring the soil-water characteristic curve were developed. Interpretative models for the distribution and geometry of the water phase in an unsaturated soil based on the capillary model have provided a useful conceptual model for understanding the effects of soil texture, gradation, void ratio, and compaction on the soil-water characteristic curve. The capillary model has also provided the foundation for recently developed techniques to predict the functional relationship between degree of saturation and shear strength, coefficient of permeability, coefficient of diffusion, and adsorption for unsaturated soils.Key words: unsaturated soils, soil-water characteristic curve, suction, shear strength, permeability, contaminant transport.
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Wotzka, Alexander, Majid Namayandeh Jorabchi, and Sebastian Wohlrab. "Separation of H2O/CO2 Mixtures by MFI Membranes: Experiment and Monte Carlo Study." Membranes 11, no. 6 (June 10, 2021): 439. http://dx.doi.org/10.3390/membranes11060439.
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The separation of CO2 from gas streams is a central process to close the carbon cycle. Established amine scrubbing methods often require hot water vapour to desorb the previously stored CO2. In this work, the applicability of MFI membranes for H2O/CO2 separation is principally demonstrated by means of realistic adsorption isotherms computed by configurational-biased Monte Carlo (CBMC) simulations, then parameters such as temperatures, pressures and compositions were identified at which inorganic membranes with high selectivity can separate hot water vapour and thus make it available for recycling. Capillary condensation/adsorption by water in the microporous membranes used drastically reduces the transport and thus the CO2 permeance. Thus, separation factors of αH2O/CO2 = 6970 could be achieved at 70 °C and 1.8 bar feed pressure. Furthermore, the membranes were tested for stability against typical amines used in gas scrubbing processes. The preferred MFI membrane showed particularly high stability under application conditions.
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Giner, Ignacio, Boray Torun, Yan Han, Belma Duderija, Dennis Meinderink, Alejandro González Orive, Teresa de los Arcos, et al. "Water adsorption and capillary bridge formation on silica micro-particle layers modified with perfluorinated organosilane monolayers." Applied Surface Science 475 (May 2019): 873–79. http://dx.doi.org/10.1016/j.apsusc.2018.12.221.
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Gharedaghloo, Behrad, and Jonathan S. Price. "Fate and transport of free-phase and dissolved-phase hydrocarbons in peat and peatlands: developing a conceptual model." Environmental Reviews 26, no. 1 (March 2018): 55–68. http://dx.doi.org/10.1139/er-2017-0002.
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Physical and chemical, and pore-scale to field-scale properties of peat soil affect the migration of non-aqueous phase liquids (NAPLs) and dissolved-phase solutes in contaminated peatlands in a way not anticipated based on the current understanding derived from their behavior in mineral soil systems. Peat pore surface wettability, which is determined by pore surface chemistry, has strong hysteresis and shows hydrophilic and hydrophobic behaviors during water drainage from and water imbibition into pore spaces. This leads to high residual NAPL saturation in pore spaces. Systematic reduction of pore radius size with depth associated with greater peat decomposition in a typical peat profile leads to an increase in NAPL-entry capillary pressure and a reduction in peat permeability with increasing depth. The former leads to stronger capillarity in deeper peat horizons, causing resistance to NAPL percolation compared to that in shallow ones; along with decreased permeability with depth, this results in higher NAPL mobility in shallower peat. The cumulative effect is preferential horizontal migration of NAPL in shallow less decomposed peat horizons. Occupation of peat macro-pores by NAPL dramatically decreases the effective water permeability and leads to lower rates of water infiltration and groundwater discharge in the contaminated area. With respect to dissolved-phase hydrocarbons, the dual porosity structure of peat soil, which exhibits larger pores and higher effective porosity near the surface, also favours preferential transport in the surface peat layer, and leads to increasing solute retardation with depth. In addition, adsorption of hydrocarbon solutes onto natural dissolved organic carbon present in peat pore water influences the effective adsorption of hydrocarbon solutes onto peat by reducing the apparent adsorption partitioning coefficient. The concepts and evidence presented in this manuscript suggest both free-phase and dissolved-phase hydrocarbon have restricted mobility in peatlands. On this basis, in large peatlands where ecological function is not notably impacted, a case can be made for allowing natural processes to degrade the hydrocarbon, rather than the common response of digging up and disposing of contaminated soils, which destroys the ecosystem function.
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Wang, Ru, and Pei Ming Wang. "Application of Styrene-Butadiene Rubber in Cement-Based Materials." Advanced Materials Research 306-307 (August 2011): 588–93. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.588.
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This paper summarizes the function of styrene-butadiene rubber (SBR) in cement-based materials, focusing on the achievements of the authors in recent years. The effect of SBR on the properties of cement mortar is introduced, i.e. the workability of fresh mortar such as the water-reduction and water-retention effects of SBR, the mechanical properties of hardened mortar such as the tensile bond strength, flexural and compressive strengths, flexibility and anti-impacting capacity, the waterproofness such as the capillary water adsorption and anti-penetration capacity, the microstructure such as the matrix structure and interface structure, and the cement hydration such as the calcium silicate hydrates, calcium aluminate hydrates and polymerization of [SiO4]4- tetrahedron.
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Loglio, Giuseppe, Volodymyr I. Kovalchuk, Alexey G. Bykov, Michele Ferrari, Jürgen Krägel, Libero Liggieri, Reinhard Miller, et al. "Interfacial Dilational Viscoelasticity of Adsorption Layers at the Hydrocarbon/Water Interface: The Fractional Maxwell Model." Colloids and Interfaces 3, no. 4 (December 10, 2019): 66. http://dx.doi.org/10.3390/colloids3040066.
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In this communication, the single element version of the fractional Maxwell model (single-FMM or Scott–Blair model) is adopted to quantify the observed behavior of the linear interfacial dilational viscoelasticity. This mathematical tool is applied to the results obtained by capillary pressure experiments under low-gravity conditions aboard the International Space Station, for adsorption layers at the hydrocarbon/water interface. Two specific experimental sets of steady-state harmonic oscillations of interfacial area are reported, respectively: a drop of pure water into a Span-80 surfactant/paraffin-oil matrix and a pure n-hexane drop into a C13DMPO/TTAB mixed surfactants/aqueous-solution matrix. The fractional constitutive single-FMM is demonstrated to embrace the standard Maxwell model (MM) and the Lucassen–van-den-Tempel model (L–vdT), as particular cases. The single-FMM adequately fits the Span-80/paraffin-oil observed results, correctly predicting the frequency dependence of the complex viscoelastic modulus and the inherent phase-shift angle. In contrast, the single-FMM appears as a scarcely adequate tool to fit the observed behavior of the mixed-adsorption surfactants for the C13DMPO/TTAB/aqueous solution matrix (despite the single-FMM satisfactorily comparing to the phenomenology of the sole complex viscoelastic modulus). Further speculations are envisaged in order to devise combined FMM as rational guidance to interpret the properties and the interfacial structure of complex mixed surfactant adsorption systems.
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Fotsing, Lucas, Marianne Fillet, Patrice Chiap, Philippe Hubert, and Jacques Crommen. "Elimination of adsorption effects in the analysis of water-soluble vitamins in pharmaceutical formulations by capillary electrophoresis." Journal of Chromatography A 853, no. 1-2 (August 1999): 391–401. http://dx.doi.org/10.1016/s0021-9673(99)00524-5.
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Mauer, Lisa J., Laurent Forny, Vincent D. M. Meunier, and Lynne S. Taylor. "Optimizing the Quality of Food Powder Products: The Challenges of Moisture-Mediated Phase Transformations." Annual Review of Food Science and Technology 10, no. 1 (March 25, 2019): 457–78. http://dx.doi.org/10.1146/annurev-food-032818-121224.
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Water is ubiquitous in the environment and is present to varying degrees even within dry powder products and most ingredients. Water migration between the environment and a solid, or between different components of a product, may lead to detrimental physical and chemical changes. In efforts to optimize the quality of dry products, as well as the efficiency of production practices, it is crucial to understand the cause–effect relationships of water interactions with different solids. Therefore, this review addresses the basis of moisture migration in dry products, and the modes of water vapor interactions with crystalline and amorphous solids (e.g., adsorption, capillary condensation, deliquescence, crystal hydrate formation, absorption into amorphous solids) and related moisture-induced phase and state changes, and provides examples of how these moisture-induced changes affect the quality of the dry products.
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COLLANTES, G. O., E. YARIV, and I. FRANKEL. "Effects of solute mass transfer on the stability of capillary jets." Journal of Fluid Mechanics 474 (January 10, 2003): 95–115. http://dx.doi.org/10.1017/s0022112002002495.
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The effects of mass transfer (e.g. via evaporation) of surface-active solutes on the hydrodynamic stability of capillary liquid jets are studied. A linear temporal stability analysis is carried out yielding evolution equations for systems satisfying general non- linear kinetic adsorption relations and accompanying surface constitutive equations. The discussion of the instability mechanism associated with the Marangoni effect clarifies that solute transfer into the jet is destabilizing whereas transfer in the opposite direction reduces instability. The general analysis is illustrated by a system satisfying Langmuir-type kinetic relations. Contrary to a clean system (i.e. in the absence of surfactants), reduced jet viscosity may lead to a substantial reduction in perturbation growth. Furthermore, the Marangoni effect gives rise to an overstability mechanism whereby perturbations whose dimensionless wavenumbers exceed unity grow with time through oscillations of increasing amplitude. The common diffusion-control approximation constitutes an upper bound which substantially overestimates the actual growth of perturbations. Considering solutes belonging to the homologous series of normal alcohols in water–air systems, the intermediate cases (e.g. hexanol–water–air which is ‘mixed-control’) are the most susceptible to Marangoni instability.
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Kazner, C., K. Lehnberg, L. Kovalova, T. Wintgens, T. Melin, J. Hollender, and W. Dott. "Removal of endocrine disruptors and cytostatics from effluent by nanofiltration in combination with adsorption on powdered activated carbon." Water Science and Technology 58, no. 8 (October 1, 2008): 1699–706. http://dx.doi.org/10.2166/wst.2008.542.
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Direct capillary nanofiltration also in combination with an upstream powdered activated carbon treatment was tested for high quality water reuse of tertiary effluent from a municipal wastewater treatment plant. Two endocrine disruptors (BPA and EE2) and two cytostatics (CytR and 5-FU) were spiked in concentrations of 1 to 2 μg/L to evaluate the process performance. In direct NF the real total removal of the micropollutants was between 5 and 40%. Adsorption to the membrane played a major role leading to a seemingly total removal between 35 and 70%. Addition of powdered activated carbon and lignite coke dust largely reduced the influence from adsorption to the membrane and increased the total removal to >95 to 99.9% depending on the PAC type and dose. The cytostatics showed already in direct NF a very high removal due to unspecified losses. Further investigations are ongoing to understand the underlying mechanism. The PAC/NF process provided a consistently high permeate quality with respect to bulk and trace organics.
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Karimi, Somayeh, and Hossein Kazemi. "Characterizing Pores and Pore-Scale Flow Properties in Middle Bakken Cores." SPE Journal 23, no. 04 (June 7, 2018): 1343–58. http://dx.doi.org/10.2118/187076-pa.
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Summary To understand the flow and transport mechanisms in shale reservoirs, we needed reliable core-measured data that were not available to us. Thus, in 2014, we conducted a series of diverse experiments to characterize pores and determine the flow properties of 12 Middle Bakken cores that served as representatives for unconventional low-permeability reservoirs. The experiments included centrifuge, mercury-intrusion capillary pressure (MICP), nitrogen adsorption, nuclear magnetic resonance (NMR), and resistivity. From the centrifuge measurements, we determined the mobile-fluid-saturation range for water displacing oil and gas displacing oil in addition to irreducible fluid saturations. From MICP and nitrogen adsorption, we determined pore-size distribution (PSD). Finally, from resistivity measurements, we determined tortuosity. In addition to flow characterization, these data provided key parameters that shed light on the mechanisms involved in primary production and the enhanced-oil-recovery (EOR) technique. The cores were in three conditions: clean, preserved, and uncleaned. The hydrocarbon included Bakken dead oil and decane, and the brine included Bakken produced water and synthetic brine. After saturating the cores with brine or oil, a set of drainage and imbibition experiments was performed. NMR measurements were conducted before and after each saturation/desaturation step. After cleaning, PSD was determined for four cores using MICP and nitrogen-adsorption tests. Finally, resistivity was measured for five of the brine-saturated cores. The most significant results include the following: Centrifuge capillary pressure in Bakken cores was on the order of hundreds of psi, both in positive and negative range. Mobile-oil-saturation range for water displacing oil was very narrow [approximately 12% pore volume (PV)] and much wider (approximately 40% PV) for gas displacing oil. In Bakken cores, oil production by spontaneous imbibition of high-salinity brine was small unless low-salinity brine was used for spontaneous imbibition. Resistivity measurements yielded unexpectedly large tortuosity values (12 to 19), indicating that molecules and bulk fluids have great difficulty to travel from one point to another in shale reservoirs.
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Zhang, Baoxin, Xuehai Fu, Ze Deng, and Ming Hao. "Characterization of Pore Structure and Its Relationship with Methane Adsorption on Medium-High Volatile Bituminous Coal: An Experimental Study Using Nuclear Magnetic Resonance." Journal of Nanoscience and Nanotechnology 21, no. 1 (January 1, 2021): 515–28. http://dx.doi.org/10.1166/jnn.2021.18512.
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A number of studies have used the nuclear magnetic resonance (NMR) technique to analyse pore characteristics and to discuss the influencing mechanisms of pore structure on methane adsorption. However, there are few studies on the dynamic characteristics of methane adsorption over time under the same temperature and pressure conditions, especially by using the cylindrical coal samples. In this study, scanning electron microscopy (SEM), mercury injection porosimetry (MIP), isothermal adsorption and NMR techniques were carried out on the four medium-high volatile bituminous coal samples from Shanxi Province, China. The simulation of methane adsorption was carried out with the custom adsorption instruments. Based on the experimental results and the Hodot pore size classification standard, the pore size distribution of the samples was analysed. In addition, the influence of nanopore structure and water content on methane adsorption was discussed. The results show that the T2 relaxation diagram of the four coal samples has a bimodal-triple peak, which reflects the complexity of the pore structure. Due to the clay minerals filling microfractures in the sample HX, the connectivity of the nanopores is reduced, in addition there is an obvious gap between the peaks in the relaxation diagram. After calculation of the T2 relaxation diagrams of the coals, the results can be converted into the pore size distribution map. The pores in the four samples are mainly composed of the macropores, followed by the mesopores, and the ratio of micropores and transition pores is relatively small. At Sw (saturated in 5% brine for 24 h) and Sir (dried at 333 K for 3 h) conditions, the adsorption capacity of the four samples presented a positive correlation with the effective porosity and the ratio of micropores, and presented a negative correlation with the ratio of mesopores, while the macropores contribute less to the adsorption. Compared with samples at Sw conditions, the adsorption capacity of the samples at Sir conditions shows an overall increasing trend, which is approximately 1.6 times that of the samples at Sw conditions on average. When a large amount of liquid water invades the nanopores and fractures, the water occupies the adsorption space of the methane due to the wettability effects and capillary pressure, which reduces the adsorption capacity.
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Zheng, C. G., B. L. Gall, H. W. Gao, A. E. Miller, and R. S. Bryant. "Effects of Polymer Adsorption and Flow Behavior on Two-Phase Flow in Porous Media." SPE Reservoir Evaluation & Engineering 3, no. 03 (June 1, 2000): 216–23. http://dx.doi.org/10.2118/64270-pa.
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Summary To determine the effect of water-soluble polyacrylamide polymer adsorption and flow behavior on oil recovery, relative permeability and mobility were determined from flow experiments at various polymer concentrations. A selective reduction of the relative permeability to water with respect to the relative permeability to oil was observed for both Berea and reservoir sandstone cores. Adsorbed polymer layer increases water wettability. Relative permeability reduction could be attributed to both wettability change and pore-size restriction due to the adsorbed polymer layer. An empirical model was proposed to correlate the relative permeability reduction and the amount of polymer adsorption. Depletion-layer effect results in a reduced polymer viscosity in porous media with respect to bulk solutions. Modification of the existing shear-rate model allows for accurate prediction of this effect. The integration of the new models in UTCHEM provides a more accurate tool for engineering design of polymer applications. Introduction Water-soluble polyacrylamide polymers have been used to reduce water production in oil wells and for mobility control in injection wells for decades.1 One of the attractive properties of polyacrylamides is their ability to reduce the relative permeability to water more than the relative permeability to oil in porous media. From the published field tests on well treatments by polymer adsorption in the 1970's and 1980's,1,2 only a few jobs were considered to be economically successful. Results could not be interpreted due to the lack of detailed information. At present, the importance of laboratory research and simulation study are emphasized for successful field design. The selective permeability reduction by polymer adsorption was traditionally termed as "permeability reduction" or "residual resistance factor," which is equivalent to the endpoint relative permeability. Previous laboratory results1 indicated that the maximum reduction of the endpoint relative permeability to water caused by polymer adsorption can be as high as a factor of 10, while the reduction of the endpoint relative permeability to oil is less than 2. If crosslinking or swelling agents are applied, the maximum reduction of the relative permeability to water could be more than two orders of magnitude. The mechanisms of this selective reduction have been explored by several researchers.3–5 An understanding of these mechanisms could be obtained from the selective permeability reduction by gels.6 Measurement of the residual resistance alone may provide a qualitative estimation. To model the effect of polymer adsorption, however, a measurement of the relative permeability is necessary, especially when residual saturation and the shape of the relative permeability curves change after polymer adsorption. Modification of the relative permeability by polymer adsorption has been intensively studied recently.3-5,7-10 Ali et al.4 and Barrufet and Ali,5 derived the relative permeability from drainage capillary pressure measured by an ultracentrifuge and showed that the reduction of the relative permeability caused by starch-based polymers is dependent on saturation. The reduction was interpreted as a change in lubrication along the pore walls. Direct measurement of relative permeability after polymer adsorption was also seen in Refs. 3 and 7 through 10. In water-wet porous media, it was found that the residual oil saturation remained almost the same after polymer treatment. At residual oil saturation, the quantity of adsorbed polymer per gram of rock was also found to be almost the same as at 100% water saturation, but the endpoint relative permeability reduction to water was increased in the presence of residual oil. Based on a capillary bundle model, a correlation of the relative permeability curves with polymer-layer thickness was proposed by Zaitoun and Kohler.3 However, the relationship of the polymer-layer thickness with the quantity of adsorbed polymer is still unknown, and further modification of the capillary bundle model may also be needed to model complex pore matrices. On the other hand, as polymer propagates through porous media, polymer solution will be diluted in the propagation front due to dispersion and adsorption, and the dilution could extend to the entire slug if the slug size is too small. So far, few researchers have related the variations of the relative permeability curves as a function of polymer concentration or the quantity of adsorbed polymer. Therefore, one of the objectives in the present study is to measure and correlate relative permeability curves as a function of polymer adsorption. Polymer solution mobility was also studied as a function of polymer concentration. Effective viscosity at low shear rate in porous media is lower than that in bulk solution at the same shear rate. The dependence of the depletion-layer effect on polymer concentration as well as porous media will be examined in this paper. Finally, the numerical models of relative permeability and mobility as a function of polymer concentration developed in this study will be incorporated in UTCHEM. Several cases will be studied to compare incremental oil recovery predicted by these new models with that predicted by previous descriptions of polymer behavior in porous media. A simplified layered reservoir model will be used for comparative simulation runs. Polymer flooding and near-wellbore polymer treatments will also be simulated. Results from these simulations should provide guidelines for future field strategies. Experiment Porous Media. Both strongly water-wet and mildly oil-wet cores were chosen to study the influence of wettability on polymer adsorption, two-phase relative permeability, and polymer solution mobility. The mildly oil-wet medium is a Warden reservoir sandstone core from Santa Fe field, Stephens County, Oklahoma. Two strongly water-wet media are Berea sandstone cores with different permeabilities. Table 1 summarizes the petrophysical properties of these sandstone samples. Fluids. Synthetic brines were prepared to represent reservoir brine (produced water) composition and makeup water (injection water) composition used in the Warden reservoir. Produced water has a total dissolved solid (TDS) of 31,300 ppm which contains 29 g/L NaCl, 0.94 g/L CaCl2, 0.77 g/L MgCl2, 0.11 g/L KCl, and 1.1 g/L NaHCO3, and injection water has a TDS of 1,490 ppm which contains 0.343 g/L CaCl2, 0.252 g/L MgCl2, 0.176 g/L Na2SO4, and 0.72 g/L NaHCO3
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Pan, Fei, Yin Luo, Li-Rong Zhang, and Jie Fu. "Degradation of Reactive Brilliant Red X-3B by zero-valent iron/activated carbon system in the presence of microwave irradiation." Water Science and Technology 64, no. 12 (December 1, 2011): 2345–51. http://dx.doi.org/10.2166/wst.2011.827.
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Reactive Brilliant Red X-3B in aqueous solution could be degraded rapidly by zero-valent iron/activated carbon in the presence of microwave irradiation (ZVI/AC/MW). From the analysis of ultraviolet–visible adsorption, chemical oxygen demand, total organic carbon, infrared spectra and capillary electrophoresis, we found the degradation was complete and no intermediates remained in the final solution treated for 2 min. Considering the many advantages including high degradation ratios, short reaction time, low costs, no intermediates and no secondary pollution, this method might be fit for dealing with various azo dye wastewaters on a large scale.
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Son, Han Am, and Taewoong Ahn. "Effect of Capillary Number on the Residual Saturation of Colloidal Dispersions Stabilized by a Zwitterionic Surfactant." Applied Sciences 11, no. 2 (January 7, 2021): 524. http://dx.doi.org/10.3390/app11020524.
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We investigated oil recovery from porous rock using nanoscale colloidal dispersions, formed by adsorption of an anionic polymer [poly-(4styrenesulfonic acid-co-maleic acid); PSS-co-MA] and a zwitterionic surfactant [N-tetradecyl-N, N-dimethyl-3-ammonio-1-propanesulfonate, TPS] onto silica nanoparticles. In an emulsion, colloidal dispersion enhanced the stability of the oil-water interface in the absence of particle aggregation; the hydrophobic alkyl chains of TPS shifted into the oil drop, not only physiochemically, stabilizing the oil-water interface, but also promoting repulsive particle-to-particle interaction. Core flooding experiments on residual oil saturation as a function of capillary number, at various injection rates and oil viscosities, showed that the residual oil level was reduced by almost half when the zwitterionic surfactant was present in the colloidal dispersion. Consequently, the result revealed that this colloidal dispersion at the interface provides a mechanically robust layer at the oil-water interface without particle aggregation. Thus, the dispersion readily entered the pore throat and adhered to the oil-water interface, lowering the interfacial tension and improving oil recovery.
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Son, Han Am, and Taewoong Ahn. "Effect of Capillary Number on the Residual Saturation of Colloidal Dispersions Stabilized by a Zwitterionic Surfactant." Applied Sciences 11, no. 2 (January 7, 2021): 524. http://dx.doi.org/10.3390/app11020524.
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We investigated oil recovery from porous rock using nanoscale colloidal dispersions, formed by adsorption of an anionic polymer [poly-(4styrenesulfonic acid-co-maleic acid); PSS-co-MA] and a zwitterionic surfactant [N-tetradecyl-N, N-dimethyl-3-ammonio-1-propanesulfonate, TPS] onto silica nanoparticles. In an emulsion, colloidal dispersion enhanced the stability of the oil-water interface in the absence of particle aggregation; the hydrophobic alkyl chains of TPS shifted into the oil drop, not only physiochemically, stabilizing the oil-water interface, but also promoting repulsive particle-to-particle interaction. Core flooding experiments on residual oil saturation as a function of capillary number, at various injection rates and oil viscosities, showed that the residual oil level was reduced by almost half when the zwitterionic surfactant was present in the colloidal dispersion. Consequently, the result revealed that this colloidal dispersion at the interface provides a mechanically robust layer at the oil-water interface without particle aggregation. Thus, the dispersion readily entered the pore throat and adhered to the oil-water interface, lowering the interfacial tension and improving oil recovery.
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Karmanov, Anatoliy Petrovich, Al'bert Vladimirovich Kanarsky, Lyudmila Sergeyevna Kocheva, Zosia Al'bertovna Kanarskaya, Venera Maratovna Gematdinova, Nikolay Ivanovich Bogdanovich, Ol'ga Andreyevna Patova, and Natal'ya Geliyevna Rachkova. "BIOSORBENTS BASED ON POLYSACCHARIDES. EVALUATION OF SORPTION CAPACITY IN RELATION TO URANIUM AND THORIUM." chemistry of plant raw material, no. 4 (December 27, 2019): 431–40. http://dx.doi.org/10.14258/jcprm.2019045210.
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Study of sorption of heavy natural radionuclide’s uranium and thorium from water by β-gluсancontaining sorbents obtained from biomass of yeast Saccharomyces Cerevisiae and bran of oat Avena sativa was carried out. It is shown that the content of mobile (water-soluble, exchange and acid-soluble) and fixed forms of uranium on investigated β-glucans vary considerably. It is found that the extent of irreversible sorption of uranium does not exceed 58.6%. For the first time shown that β-glucans have high sorption capacity in ratio of thorium. In the conditions of the experiments it was retrieved more than 99% of thorium from the water. The content of fixed form of thorium reaches 94% of the sorbed. Characteristics of surface and capillary-porous structure of samples were defined. The correlation relationships between rates of adsorption and specific surface of preparations were installed. An analysis of the relationship between sorption capacity and various properties of glucans leads to the conclusion that the most important role for the implementation of a strong adsorption of heavy radionuclides belongs to chemisorptions mechanisms, while the contribution of surface physical phenomena is not essential. It is shown that the highest strong adsorption of thorium is characterized by a sample representing the cell walls of yeast Saccharomyces cerevisiae. The findings suggest of β-glucans prospects in practical terms and their use as polyfunctional enterosorbеnts.
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Rueda, Edgar, Salem Akarri, Ole Torsæter, and Rosangela B. Z. L. Moreno. "Experimental Investigation of the Effect of Adding Nanoparticles to Polymer Flooding in Water-Wet Micromodels." Nanomaterials 10, no. 8 (July 29, 2020): 1489. http://dx.doi.org/10.3390/nano10081489.
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Recently, the combination of conventional chemical methods for enhanced oil recovery (EOR) and nanotechnology has received lots of attention. This experimental study explores the dynamic changes in the oil configuration due to the addition of nanoparticles (NPs) to biopolymer flooding. The tests were performed in water-wet micromodels using Xanthan Gum and Scleroglucan, and silica-based NPs in a secondary mode. The microfluidic setup was integrated with a microscope to capture the micro-scale fluid configurations. The change in saturation, connectivity, and cluster size distributions of the non-wetting phase was evaluated by means of image analysis. The biopolymer content did not affect the ability of the NPs to reduce the interfacial tension. The experiments showed that the reference nanofluid (NF) flood led to the highest ultimate oil recovery, compared to the Xanthan Gum, Scleroglucan and brine flooding at the same capillary number. In the cases of adding NPs to the biopolymer solutions, NPs-assisted Xanthan flooding achieved the highest ultimate oil recovery. This behavior was also evident at a higher capillary number. The overall finding suggests a more homogenous dispersion of the NPs in the solution and a reduction in the polymer adsorption in the Xanthan Gum/NPs solution, which explains the improvement in the sweep efficiency and recovery factor.
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Andersen, Pål Østebø. "Capillary Pressure Effects on Estimating the Enhanced-Oil-Recovery Potential During Low-Salinity and Smart Waterflooding." SPE Journal 25, no. 01 (December 18, 2019): 481–96. http://dx.doi.org/10.2118/191974-pa.
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Summary Many experimental studies have investigated smart water and low-salinity waterflooding and observed significant incremental oil recovery after changes in the injected-brine composition. The common approach to model such enhanced-oil-recovery (EOR) mechanisms is by shifting the input relative permeability curves, particularly including a reduction of the residual oil saturation. Cores that originally display oil-wetness can retain much oil at the outlet of the flooded core because of the capillary pressure being zero at a high oil saturation. This end effect is difficult to overcome in highly permeable cores at typical laboratory rates. Injecting a brine that changes the wetting state to less-oil-wet conditions (represented by zero capillary pressure at a lower oil saturation) will lead to a release of oil previously trapped at the outlet. Although this is chemically induced incremental oil, it represents a reduction of remaining oil saturation, not necessarily of residual oil saturation. This paper illustrates the mentioned issues of interpreting the difference in remaining and residual oil saturation during chemical EOR and hence the evaluation of potential smart water effects. We present a mathematical model representing coreflooding that accounts for wettability changes caused by changes in the injected composition. For purpose of illustration, this is performed in terms of adsorption of a wettability-alteration (WA) component coupled to the shifting of relative permeability curves and capillary pressure curves. The model is parameterized in accordance with experimental data by matching brine-dependent saturation functions to experiments where wettability alteration takes place dynamically because of the changing of one chemical component. It is seen that several effects can give an apparent smart water effect without having any real reduction of the residual oil saturation, including changes in the mobility ratio, where the oil already flowing is pushed more efficiently, and the magnitude of capillary end effects can be reduced because of increased water-wetness or because of a reduction in water relative permeability giving a greater viscous drag on the oil.
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Fournel, L., P. Mocho, J. L. Fanlo, and P. Le Cloirec. "External Capillary Condensation and Adsorption of VOCs onto Activated Carbon Fiber Cloth and Felt." Environmental Technology 26, no. 11 (November 2005): 1277–88. http://dx.doi.org/10.1080/09593332608618598.
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