• Title/Summary/Keyword: alkali salts

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Employing high-temperature gas flux in a residual salt separation technique for pyroprocessing

  • Kim, Sung-Wook;Heo, Dong Hyeon;Kang, Hyun Woo;Hong, Sun-Seok;Lee, Sang-Kwon;Jeon, Min Ku;Hur, Jin-Mok;Choi, Eun-Young
    • Nuclear Engineering and Technology
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    • v.51 no.7
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    • pp.1866-1870
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    • 2019
  • Residual salt separation is an essential step in pyroprocessing because its reaction products, as prepared by electrochemical unit processes, contain frozen residual electrolyte species, which are generally composed of alkali-metal chloride salts (e.g., LiCl, KCl). In this study, a simple technique that utilizes high-temperature gas flux as a driving force to melt and push out the residual salt in the reaction products was developed. This technique is simple as it only requires the use of a heating gun in combination with a gas injection system. Consequently, $LiNO_3-ZrO_2$ and $LiCl-ZrO_2$ mixtures were successfully separated by the high-temperature gas injection (separation efficiency > 93%), thereby demonstrating the viability of this simple technique for residual salt separation.

Degradation mechanisms of concrete subjected to combined environmental and mechanical actions: a review and perspective

  • Ye, Hailong;Jin, Nanguo
    • Computers and Concrete
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    • v.23 no.2
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    • pp.107-119
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    • 2019
  • In-service reinforced concrete structures are simultaneously subjected to a combination of multi-deterioration environmental actions and mechanical loads. The combination of two or more deteriorative actions in environments can potentially accelerate the degradation and aging of concrete materials and structures. This paper reviews the coupling and synergistic mechanisms among various deteriorative driving forces (e.g. chloride salts- and carbonation-induced reinforcement corrosion, cyclic freeze-thaw action, alkali-silica reaction, and sulfate attack). In addition, the effects of mechanical loads on detrimental environmental factors are discussed, focusing on the transport properties and damage evolution in concrete. Recommendations for advancing current testing methods and predictive modeling on assessing the long-term durability of concrete with consideration of the coupling effects are provided.

The Effect of Metallic Oxides on the Formation Rates and Rigidities of the Elastic Sodium Alginate-$CaSO_4{\cdot}1/2H_2O$ Gel. (Sodium Alginate-$CaSO_4{\cdot}1/2H_2O$ 彈性體의 生成速度 및 彈性에 미치는 金屬酸化物의 影響)

  • Shin, Hong-Dae;Huh, Yeonn;Kim, Uun-Sik
    • Journal of the Korean Chemical Society
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    • v.9 no.1
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    • pp.16-22
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    • 1965
  • The time-lag-effect of alkali salts on the gelation of sodium alginate-$CaSO_4{\cdot}$1/2 $H_2O$ is compared with Miyake's data, and then the formation rate of the elastics measured by the continuous method (an improved Schwedoff's method) and the change of rigidity with metallic oxides are studied as follows: (1) The gelation processes of sodium alginate and $CaSO_4{\cdot}$1/2 $H_2O$-aqueous sol are studied by measuring, continuously the increases of tensions ofsamples. (2) The time-lag-effect of $Na_3PO_4$ on the formation rate of the elastic gel is larger than that of $Na_2CO_3$, but the difference between the effects of the two alkali salts on the rate is found not so greater than predicted in Miyake's data. (3) Any regularities of the effect on the rate by metallic oxides are not observed. The increasing effects of the rates of $SiO_2$ and MgO are relatively large, and that of ZnO is relatively small. However, $Al_2O_3$, $Sb_2O_3$ and $TiO_2$show some decreasing effects. As a result it is noted that the regularities do not depend on the effect of oxide species and their amounts. (4) It is not found proportionality between the rigidity and the gelation rate. However, the increasing effect of the rigidity with the addition of metallic oxides can be observed. The rigidity increasing rate of MgO is the largest of them.

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Changes of Properties in Cinnamon Extracts Prepared by Enzyme Hydrolysis and Addition of Salts, Sugars and Antioxidant Synergists (효소분해와 염과 당 및 항산화 작용 상승제의 첨가에 의한 계피 추출액의 특성 변화)

  • Kim, Na-Mi;Do, Jae-Ho;Lee, Jong-Soo;Kim, Woo-Jung
    • Applied Biological Chemistry
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    • v.37 no.4
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    • pp.272-276
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    • 1994
  • The dried cinnamon was extracted with enzymes, salts, sugars and additives in order to find the most effective extraction material. Enzymatic hydrolysis of cinnamon suspension with cellulase, hemicellulase, pectinase, ${\beta}-1.4-glucosidase$, tannase and lipase showed a little increase of their cinnamic aldehyde contents. Solid yield, antioxidant activity and degree of browning were increased in hemicellulase treatment. Acid and alkali extraction of cinnamon showed a some increase in solid yields and antioxidant activity was increased by addition of glucose and Na-ascorbate. Cinnamic aldehyde contents and degree of browning were increased in extraction with Na-citrate addition.

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Counterion Specific Conformational Transition and ion Selective Transport of a Poly(L-glutamic acid)/PVA Blend Membrane (Poly(L-glutamic acid)/PVA 블렌드막의 대이온 선택적인 구조전이와 이온투과 특성)

  • 허양일
    • Polymer(Korea)
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    • v.24 no.6
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    • pp.802-809
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    • 2000
  • Counterion-specific helix formation and ion-selective transport of alkali metal chlorides (LiCl, NaCl, KCl, CsCl) were investigated for a poly(L-glutamic acid)(PLGA)/poly (vinyl alcohol)(PVA) blend membrane immersed in aqueous ethanol. The counterion specificity for helix formation of PLG alkali metal salts in the membrane was Li>Na>K>Cs. This specificity is ascribed to a contact ion-pair formation between the PLG carboxyl anion and the bound counterion, which depends on the energy balance between the electrostatic interaction and the desolvation. In aqueous ethanol, an appreciable ion-selectivity was observed for the permeability coefficient, i.e. Li$^{+}{\cdot}$Cl$^{-}$) formation between counterion and coion, and the latter to a specific interaction of diffusing counterions with polymer charges.

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Characterization of Glycine Metal Salts for $CO_2$ Absorption (이산화탄소 흡수를 위한 글리신 금속염의 특성 연구)

  • Lim, Yun-Hui;Park, Young Koo;Jo, Young-Min
    • Applied Chemistry for Engineering
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    • v.23 no.3
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    • pp.284-288
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    • 2012
  • This work deals with the chemical characterization of glycine aqueous solution in $CO_2$ absorption. Three alkali elements were impregnated into the glycine in order to facilitate the formation of amino functionalities. The analysis by IR revealed the transformation of ammonium ions to the amino group. In addition, the NMR analysis showed that the substitution of metal cations to the chemical shift of hydrogen and carbon atoms in glycine; in order of lithium glycinate, sodium glycinate and potassium glycinate depending on the electro negativity. Meanwhile, the $CO_2$ absorption at room temperature was the highest in primary amine solution, but at the increasing temperature sodium glycinate could capture more $CO_2$ than that of the pure amine solution.

Effect of Al Alloy Composition on Physical and Crystallographical Properties of Plasma Electrolytic Oxidized Coatings I. Physical Properties of PEO Layer (플라즈마 전해 산화 코팅에 있어서 알루미늄 합금 모재 성분의 물리적, 결정학적 영향 I. PEO 층의 물성)

  • Kim, Bae-Yeon;Lee, Deuk-Yong;Kim, Yong-Nam;Jeon, Min-Seok;Song, Jun-Kwang;Kim, Sung-Youp;Kim, Kwang-Youp
    • Journal of the Korean Ceramic Society
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    • v.47 no.3
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    • pp.256-261
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    • 2010
  • Physical properties of Plasma electrolytic oxidized 8 different types of Al alloys, A-1100, A-2024, A-5052, A-6061, A-6063, A-7075, ACD-7B and ACD-12 were investigated. The electrolyte for PEO was $Na_2SiO_3$ solutions with NaOH and some alkali earthen metal salts. Porous layer near the surface of PEO coating was not found, and surface roughness Ra50 was below 2.5 ${\mu}m$. Surface roughness was affected by growth rate of plasma electrolytic oxidized layer, not by Si content in Al alloy.

Preparation of Fine Silk Powder and It′s Application for Surface Modification (폐견사류의 미세분말화 및 표면 가공제 적용)

  • 이용우;이광길;여주홍;김종호
    • Journal of Sericultural and Entomological Science
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    • v.43 no.1
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    • pp.41-48
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    • 2001
  • The purification, dissolution and powdering of stained waste silk obtained from weaving and dyeing process were studied for the surface modification of textile fabric and plastic materials. The whiteness of stained waste silk could be improved through degumming and bleaching with sodium hydrosulfite. The water-soluble fibroin solution can be obtained by dissoving the degummed waste silk in a boiling solution of 50% calcium chloride for 60 minutes. The salts and heavy metals contained in fibroin solution were removed by electric dialysis, wool fiber filtration and gel filtration chromatography. The fibroin powder was prepared by using a fine grinder after the alkali treatment for weakening the silk fiber. The fine fibroin powder of particle size around 30 ㎛ was obtained with a ultra fine-mill, while it was finer below 10 ㎛ with a ball-mill. The dissolved or powdered silk was applied to the surface of fabric with addition of the binder (a urethane resin). The moisture content of polyester and nylon fabrics treated with the silk solution was improved due to hygroscopic property of silk. The fine fibroin powder mixed with the binder ws coated on the surface of synthetic film by use of the air pressed sprayer. It was revealed that the hygroscopicity as well as the softness of fibroin powder coated film was much improved. Therefore, it is thought that the fine silk fibroin powder is applicable as an coating agent for the surface modification of plastic and synthetic leather.

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Effect of Al Alloy Composition on Physical and Crystallographical Properties of Plasma Electrolytic Oxidized Coatings II. Crystallographic Analysis of PEO Layer (플라즈마 전해 산화 코팅에 있어서 알루미늄 합금 모재 성분의 물리적, 결정학적 영향 II. PEO 층의 결정상 분석)

  • Kim, Bae-Yeon;Lee, Deuk-Yong;Shin, Min-Chul;Shin, Hyun-Gyoo;Kim, Byeong-Kon;Kim, Sung-Youp;Kim, Kwang-Youp
    • Journal of the Korean Ceramic Society
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    • v.47 no.4
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    • pp.283-289
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    • 2010
  • Physical properties of Plasma electrolytic oxidized 8 different kinds of Al alloys, A-1100, A-2024, A-5052, A-6061, A-6063, A-7075, ACD-7B and ACD-12 were investigated. The electrolyte for PEO was $Na_2SiO_3$ and NaOH and some alkali earthen metal salts system solution. $\eta$-alumina, as well as $\gamma$-alumina, was main crystal phase, which were ever reported. Also, $Al_{4.95}Si_{1.05}O_{9.52}$ was found only in this research. So we can conclude that the process conditions of PEO apparatus and composition and concentration of its electrolyte affects crystal structure and physical properties of PEO layers much more than the compositions of Al alloy.

Characteristics of Hemolysin from Bacillus thuringiensis subsp. israelensis (Bacillus thuringiensis subsp. israelensis 균주의 Hemolysin 성질)

  • 황지연;김광현
    • Microbiology and Biotechnology Letters
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    • v.15 no.6
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    • pp.425-429
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    • 1987
  • The extra-cellular hemolysin from Bacillus thuringiensis subsp. israelensis was purified in the process of suiting with (NH$_4$)$_2$SO$_4$, Sephadex G-200 gel filtration, and DEAE-cellulose column chromatography. The purified hemolysin had molecular weight of approximately 47,000 dalton on SDS-polyacrylamide gel electrophoresis. The activity of purified hemolysin on human red blood cells was increased by thiol agents, but that was Inhibited by cholesterol, protease treatment, and metal salts such as CuSO$_4$, and FeSO$_4$, respectively.

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