• Title/Summary/Keyword: mixed salt

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Fates of water and salts in non-aqueous solvents for directional solvent extraction desalination: Effects of chemical structures of the solvents

  • Choi, Ohkyung;Kim, Minsup;Cho, Art E.;Choi, Young Chul;Kim, Gyu Dong;Kim, Dooil;Lee, Jae Woo
    • Membrane and Water Treatment
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    • v.10 no.3
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    • pp.207-212
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    • 2019
  • Non-aqueous solvents (NASs) are generally known to be barely miscible, and reactive with polar compounds, such as water. However, water can interact with some NASs, which can be used as a new means for water recovery from saline water. This study explored the fate of water and salt in NAS, when saline water is mixed with NAS. Three amine solvents were selected as NAS. They had the same molecular formula, but were differentiated by their molecular structures, as follows: 1) NAS 'A' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain, 2) NAS 'B' with symmetrical structure and having the hydrophilic group (NH) at the middle of the straight carbon chain, 3) NAS 'C' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain but possessing a hydrophobic ethyl branch in the middle of the structure. In batch experiments, 0.5 M NaCl water was blended with NASs, and then water and salt content in the NAS were individually measured. Water absorption efficiencies by NAS 'B' and 'C' were 3.8 and 10.7%, respectively. However, salt rejection efficiency was 98.9% and 58.2%, respectively. NAS 'A' exhibited a higher water absorption efficiency of 35.6%, despite a worse salt rejection efficiency of 24.7%. Molecular dynamic (MD) simulation showed the different interactions of water and salts with each NAS. NAS 'A' formed lattice structured clusters, with the hydrophilic group located outside, and captured a large numbers of water molecules, together with salt ions, inside the cluster pockets. NAS 'B' formed a planar-shaped cluster, where only some water molecules, but no salt ions, migrated to the NAS cluster. NAS 'C', with an ethyl group branch, formed a cluster shaped similarly to that of 'B'; however, the boundary surface of the cluster looked higher than that of 'C', due to the branch structure in solvent. The MD simulation was helpful for understanding the experimental results for water absorption and salt rejection, by demonstrating the various interactions between water molecules and the salts, with the different NAS types.

Preparation of La0.5Nd0.5Ni5 Alloy by an Electrochemical Reduction in Molten LiCl (LiCl 용융염에서 전해환원법을 통한 La0.5Nd0.5Ni5 합금 제조)

  • Lim, Jong Gil;Jeong, Sang Mun
    • Korean Chemical Engineering Research
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    • v.53 no.2
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    • pp.145-149
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    • 2015
  • The electrochemical behavior of $Nd_2O_3-La_2O_3-NiO$ mixed oxide including rare earth resources has been studied to synthesize $La_{0.5}Nd_{0.5}Ni_5$ alloy in a LiCl molten salt. The $Nd_2O_3-La_2O_3-NiO$ mixed oxide was converted to $NiNd_2O_4$ (spinel) and $LaNiO_3$ (perovskite) structures at a sintering temperature of $1100^{\circ}C$. The spinel and perovskite structures led a speed-up in the electrolytic reduction of the mixed oxide. Various reaction intermediates such as Ni, $NiLa_2O_4$ were observed during the electrochemical reduction by XRD analysis. A possible reaction route to $La_{0.5}Nd_{0.5}Ni_5$ in the LiCl molten salt was proposed based on the analysis result.

Effect of Salting Methods on Component and Quality Characteristics of Eggplants (가지의 절임방법에 따른 성분변화)

  • Yoon, Kyung-Young;Hong, Ju-Yeon;Shin, Seung-Ryeul
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.6
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    • pp.786-790
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    • 2006
  • This study was carried out to analyze the physicochemical properties according to salting methods of eggplants exported mainly to Japan. Moisture contents of Chukyang and Shikibu were decreased after 3 days of salting regardless of salting methods. The decrease of moisture content in mixed treatment of rice husk and salt was higher than that of salt treatment after 7 days of salting. Ash contents of Chukyang and Shikibu were increased according to extended salting time regardless of salting methods. The Brix of Chukyang and Shikibu without salting were $4.0^{\circ}brix\;and\;5.0^{\circ}brix$, respectively, and were increased according to extended salting time regardless of kinds and salting methods. pH of Chukyang and Shikibu without salting were 6.04 and 6.00, respectively. Extended the salting time from 0 to 7 days did not result in a pH change. Reducing sugar contents of Chukyang and Shikibu were increased according to extended salting time, the increase of reducing sugar content in mixed treatment of rice husk and salt was higher than that of salt treatment during salting. Soluble protein contents of Chukyang and Shikibu without salting were 1.40 g and 1.85 g, respectively. Extended the salting time from 0 to 7 days resulted in gradual increase in soluble protein content of Chukyang and Shikibu.

A Study on the Micellization of Sodium Dodecyl Sulfate in 𝜔-Phenylakylammonium Salt Solution (𝜔-Phenylalkylammonium Salt의 수용액에서 Sodium Dodecyl Sulfate의 미셀에 관한 연구)

  • Ryu, Yeanho;Oh, Jung Hee
    • Applied Chemistry for Engineering
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    • v.8 no.6
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    • pp.1041-1047
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    • 1997
  • The influence of $\omega$-phenylalkylammonium salt on the critical micelle concentration (CMC) of SDS has been examined using the electric conductivity method. CMC of SDS exhibited the tendency to decrease with the length of alkyl group of additives. The effect of temperature on CMC of SDS in additive solutions has been observed in the range of $18^{\circ}C-50^{\circ}C$. The free energy(${\Delta}G_m^{\circ}$) for the micellization of SDS is negative and the entropy(${\Delta}S_m^{\circ}$) is a large positive value. The enthalpy(ΔHm0is positive in low temperature($18^{\circ}C$) and negative in high temperature($>25^{\circ}C$). In the prensence of organic additives, the micellization of SDS was considered as a spontaneous process and to involve a phase transition. The values of ΔGm0has shown the tendency to increase but the values of ${\Delta}S_m^{\circ}$ and ${\Delta}H_m^{\circ}$ to decrease with the length of alklyl group of additive salts. The changes in ${\Delta}\kappa$(difference of specific conductivity) with increasing mole ratio of additives in the mixed solutions indicated the formation of mixed micelles between SDS and additives. The effect of the length of alkyl chain on the micellization of SDS demonstrated the penetration of organic additives into the palisade layer of the SDS micelle.

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Effect of AlF3 on Zr Electrorefining Process in Chloride-Fluoride Mixed Salts for the Treatment of Cladding Hull Wastes (폐 피복관 처리를 위한 염소계-불소계 혼합용융염 내 지르코늄 전해정련공정에서 삼불화알루미늄의 효과 연구)

  • Lee, Chang Hwa;Kang, Deok Yoon;Lee, Sung-Jai;Lee, Jong-Hyeon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.2
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    • pp.127-137
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    • 2019
  • Zr electrorefining is demonstrated herein using Zirlo tubes in a chloride-fluoride mixed molten salt in the presence of $AlF_3$. Cyclic voltammetry reveals a monotonic shift in the onset of metal reduction kinetics towards positive potential and an increase in intensity of the additional peaks associated with Zr-Al alloy formation with increasing $AlF_3$ concentration. Unlike the galvanostatic deposition mode, a radial plate-type Zr growth is evident at the top surface of the salt during Zr electrorefining at a constant potential of -1.2 V. The diameter of the plate-type Zr deposit gradually increases with increasing $AlF_3$ concentration. Scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) and X-ray photoelectron spectroscopy (XPS) analyses for the plate-type Zr deposit show that trace amount of Al is incorporated as Zr-Al alloys with different chemical compositions between the top and bottom surface of the deposit. Addition of $AlF_3$ is effective in lowering the residual salt content in the deposit and in improving the current efficiency for Zr recovery.

The Changing Process of the Tidal Landforms in Hampyeung Bay, Southwest Korea (함평만의 간석지 해안지형의 변화)

  • KIM, Nam-Shin;LEE, Min-Boo
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.4
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    • pp.223-233
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    • 2011
  • The aims of this study is about distribution characteristics of tidal coastal landforms, and that changing process in the Hampyeung Bay, which has a semi-enclosed bay like basin shape without inflow of stream, the mouth of open sea is narrow and forms with wide ends toward inland sea. The source of deposits are moved materials by tidal currents and from coastal slopes. Main landform elements of study area consist of tidal flat, tidal channels, intertidal sand bar, sea cliffs, and sea terrace. Tidal flats is classified with mud flat and mixed flat by grain size composition. Mud flats have developed at the shoreline area that tidal flat is closed to the continuity of gentle slope, and mixed flat developed at the foot of the sea cliffs and sea terraces. Quaternary deposits were identified in the coastal materials sedimented by the sea-level change. According to the analysis of grain size composition during last ten years, sands and silt has increased 2% and 6% respectively, clay has been decreased by 9%. The concaved tidal flats are colonized by salt plants. Areal changes of salt plants expanded near four times from 2.4km2 at the year 2001 to 9.3km2 at the year 2009. During the same periods, mean grain size became coarser from 6.5φ to 4.5φ at the salt plants area.

The Worldwide Trend of waste Treatment Technology and DAEWOO-TS Gasification & Melting System (세계의 폐기물처리기술 동향과 DAEWOO-TS 열분해 가스화 용융기술)

  • 허일상;김우봉
    • Environmental Analysis Health and Toxicology
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    • v.16 no.2
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    • pp.103-114
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    • 2001
  • Worldwide trend of waste treatment technology is rapidly transferring from "incineration system" to "gasification & melting system" which can derive the resources from waste and charge no more environmental burden to nature. And therefore it is necessary for our country to adopt gasification & melting system urgently to present the land pollution and lack of landfill area. Among several gasification and melting processes Daewoo-Thermoselect gasification and melting system is the representative process which can transfer waste to resources such as sin-gas, molten slag, metal hydroxide, mixed salt and sulfur through the process of compaction, degasification, gasification and melting.

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The Gasification & Melting Treatment Technology of Waste (폐기물 열분해 가스화용융 기술)

  • Huh, Il-Sang
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.133-138
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    • 2005
  • The worldwide trend of waste treatment technology is rapidly transferring from "incineration system" to "gasification & melting system" which can derive the resources from waste and charge no more environmental burden to nature. And therefore it is necessary to adopt gasification & melting system to prevent the land pollution and to solve the problem of landfill area. Among several thermal waste treatment processes gasification and melting system is the representative process which can transfer waste to resources such as syn-gas, molten slag, metal hydroxide, mixed salt and sulfur through the process of compaction, pyrolysis, gasification and melting.

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Study on Simultaneous Material Transport through Charged Mosaic Membrane

  • Myeongkwan Song;Lee, Jang-Oo;Akira Yamauchi;Wongkang Yang
    • Proceedings of the Membrane Society of Korea Conference
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    • 2004.05a
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    • pp.109-112
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    • 2004
  • The charged mosaic membranes having cation and anion exchange mixed groups within membrane were researched. The composite charged mosaic membrane was investigated from simultaneous transport such as solute and solvent flux. On the other hand, the reflection coefficient and salt flux coefficient were estimated by taking account of the cross constants of the phenomenological equation.(omitted)

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Spectrophotometric determination of acetylsalicylic acid with copper-$\alpha$-picolin complex in tetrachloromethane ($\alpha$-picolin동에 의한 aspirin의 용매 흡광도 정량법)

  • 백남호;박만기
    • YAKHAK HOEJI
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    • v.13 no.2_3
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    • pp.80-83
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    • 1969
  • Acetylsalicylic acid gives a water-insoluble violet complex with $<\alpha>$-Picolin-Cu(II) reagent. The Complex is extractable well with a mixture of $<\alpha>$-Picolin-tetrachloromethane solution. The Complex salt dissolved in the mixed solution shows a maximum absorption at 620 m$<\mu>$. It has a melting point at $171^{\circ}C-$173^{\circ}C and molar ratio of Acetylsalicylic acid: Cu(II): $<\alpha>$-Picolin was estimated as 2:1:2 by continuous variation method and chelate titration method.

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