• Title/Summary/Keyword: SALT REDUCTION

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Effect of Colloidal Silica on the Solidification of Galvanized Coatings (용융아연 도금층의 응고에 미치는 콜로이달 실리카의 영향)

  • 김상헌;정원섭;김형인
    • Journal of the Korean institute of surface engineering
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    • v.33 no.5
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    • pp.381-386
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    • 2000
  • It was found that colloidal silica sprayed to the galvanized steel sheet apparently made the molten zinc layer solidified to be the randomly oriented fine grains. Its spraying effect was also little affected by steel temperature that had been considered as one of the major operating factors in this process. From the results of surface analysis, it is considered that aluminum dissolved in coating layer reduces silica to silicon by the oxidation-reduction reaction, and that the reduced silicon acts as a more effective nucleus in solidification reaction than phosphate salt, siica and alumina.

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Application of Phase-Field Theory to Model Uranium Oxide Reduction Behavior in Electrolytic Reduction Process (전해환원 공정의 우라늄 산화물 환원 거동 모사를 위한 Phase-Field 이론 적용)

  • Park, Byung Heung;Jeong, Sang Mun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.3
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    • pp.291-299
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    • 2018
  • Under a pyro-processing concept, an electrolytic reduction process has been developed to reduce uranium oxide in molten salt by electrochemical means as a part of spent fuel treatment process development. Accordingly, a model based on electrochemical theory is required to design a reactor for the electrolytic reduction process. In this study, a 1D model based on the phase-field theory, which explains phase separation behaviors was developed to simulate electrolytic reduction of uranium oxide. By adopting parameters for diffusion of oxygen elements in a pellet and electrochemical reaction rate at the surface of the pellet, the model described the behavior of inward reduction well and revealed that the current depends on the internal diffusion of the oxygen element. The model for the electrolytic reduction is expected to be used to determine the optimum conditions for large scale reactor design. It is also expected that the model will be applied to simulate the integration of pyro-processing.

Sulfur Dioxide, Mineral Contents and Physicochemical Properties Generated during Manufacture of Bamboo Salt (죽염 제조공정에 따른 이산화황, 미네랄 함량 및 이화학적 특성)

  • Kim, Hag-Lyeol;Lee, Seong-Jae;Lee, Jung-Hee;Kim, In-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.8
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    • pp.1248-1256
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    • 2014
  • The purpose of this study was to investigate the mechanisms of behind $SO_2$ formation and elevated cause of reducing power in purple bamboo salt (PBS) along with an analysis of physicochemical properties, content of sulfur compounds, oxidation reduction potential (ORP), mineral contents of salt type (MSS, mudflat solar salt; BS, bamboo salt), and addition of raw bamboo (RB). $SO_2$ content of 630 ppm was detected in PBS. $SO_2$ was not detected in MSS, BS, or RB, whereas $SO_2$ (782 ppm) from $K_2SO_4$ was detected after heating a NaCl, KCl, $MgCl_2$, $MgSO_4$, MgO, $CaCl_2$, $K_2SO_4$, and $FeSO_4$ with RB. $SO_2$ content of BS increased with baking time, and it originated from BSRB1 (13.88 ppm) to BSRB4 (109.13 ppm). $SO_3{^{2-}}$ originated only from MSSRB4 and BSRB2~BSRB4. Sulfate ion content decreased along with increasing $SO_2$ and sulfite ion contents. ORP increased with baking time of MSS and BS, and it was present at higher levels in BSRB4 (-211.40 mV) of BS than MSS. Insoluble content was higher in BS than MSS. Further, Ca, K, and Mg ion contents decreased in MSS and increased in BS with baking time. BSRB4 had 1.4 fold higher levels of Ca, 1.5 fold higher levels of Mg, and 1.8 fold higher levels of K than BS. Li, Al, Mn, Fe, and Sr in MSS as well as Al, Fe, and Ni in BS increased with baking time. Anions (Cl, $NO_3$, and Br) and heavy metals (Pb, Cd, Hg, and As) between MSS and BS were not significantly different. These results suggest that the reducing power of BS was due to $SO_2$ and sulfite ion. To increase the amounts of these compounds and reducing power, higher melting temperature and longer baking time are necessary along with BS, which is created by the addition of RB to roasted salt.

Factors contributing to the reduction of sodium intake by food manufacture and cooking venues according to the national sodium reduction policies (국가 나트륨 저감화 정책에 따른 생산 및 조리 주체별 나트륨 섭취 감소 기여 요인 분석)

  • Kim, Kirang;Park, Sohyun;Kim, Jee Young
    • Journal of Nutrition and Health
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    • v.53 no.6
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    • pp.648-662
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    • 2020
  • Purpose: Sodium intake is persistently decreasing because of the government's sodium reduction policy. This study aimed to identify foods and dishes that contributed to the reduction of sodium intake and evaluate the effects of the sodium reduction policy. Methods: The subjects were 57,809 participants in the Korea National Health and Nutrition Survey from 2010 to 2017. To identify food and dish sources of sodium intake, the food and dish groups were classified into 23 and 21 groups, respectively. Foods and dishes that contributed to sodium intake were categorized according to the production and cooking venues: production by manufacturers, home cooking, cooking at catering service, and restaurant cooking. Results: Sodium intake was 4,876 mg in 2010 to 3,477 mg in 2017, showing a 29.7% decrease in intake in 2010. Sodium intake was decreased mainly in foods produced by manufacturers and home-cooked foods. The main contributory factors to sodium from the food and dish groups differed according to the food manufacturer and cooking venue. The kimchi produced by manufacturers, cooked soup/tang/jjigae/hotpot at home and catering services, and cooked noodles/dumplings in restaurants were the main contributors to the sodium intake. Conclusion: The type of foods and dishes that contribute to sodium intake tended to expand over the years from specific foods and dishes to various groups of foods and dishes. These results provide evidence for the development and production of low-salt foods and dietary education related to low-salt intake.

Assessment of Salt Resistance and Performances of LID Applicable Plants (LID시설에 적용된 식물의 염분 저항성 및 효과 평가)

  • Choi, Hyeseon;Hong, Jungsun;Lee, Soyung;Kim, Lee-Hyung
    • Journal of Wetlands Research
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    • v.18 no.2
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    • pp.201-207
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    • 2016
  • In LID facilities treating stormwater runoff, various kinds of plants are applied for water circulation recovery and pollutant reduction. However, rapid changes of soil moisture due to the use of porous media and spread of deicing material during winter season cause slow plant growth that detrimentally leads to many problems including death of plants. Therefore, this study was performed to evaluate the salt resistance of plants, its effects on pollutants removal, and water circulation recovery. Eight different kinds of plants applicable to an LID facility were selected for the experiment, which were Bridal wreath (Spiraea japonica, S.J), Azalea (Rhododendron indicum, R.I), Dawn Redwood (Metasequoia glyptostroboides, M.G), Sweet flag (Acorus calamus A.C), Dwarf fan-shape columbine(Aquilegia flabellata, A.F), Pink (Dianthus chinensis, D.C), Pratia pedunculata (Pratia pedunculata, P.B) and Marigold (Tagetes patula, T.P). Woody plants such as S.P, R.I, and M.G appear to have less salt resistance compared to the other herbaceous plants. Specifically, M.G achieved the highest salt resistance among the other woody plants being followed by S.P, and R.I, respectively. For herbaceous plants, T.L and D.C have the higher salt resistances than that of A.C, P.B, and A.F, respectively. Regardless of the influence of salt to most of the plants, TN and TP were reduced more than 60% and the study suggests the M.G showed high pollutant removal efficiency and provided better water circulation by means of active photosynthesis and respiration due to higher growth.

Linkage Between Brown Planthopper Resistance Gene and Salt Tolerance in Rice (벼멸구 저항성 유전자와 내염성과의 연관)

  • Yang Dae Hwa;Kim Jin-Hong;Wi Seung Gon;Baek Myung-Hwa;Lim Sang Yong;Lee In Sok;Lee Kyu-Seong;Lee Myung Chul;Lim Yong-Pyo;Chung Byung Yeoup;Kim Jae-Sung
    • Journal of Life Science
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    • v.15 no.1 s.68
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    • pp.61-65
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    • 2005
  • Using two japonica rice cultivars (Ilpumbyeo and Sanghaehyanghyella), which are distinguishable by the brown planthopper (BHP) resistance maker (R208), a relationship between the BPH resistance gene (Os-Bil) and salt-tolerance was investigated. To do this, changes in the expression level of Os-Bil by the salt stress were quantified by the real-time PCR in the two cultivars, and compared with those in other two indica rice cultivars (Pokkali and IR29). In Ilpumbyeo, the expression level of Os-Bil decreased by the treatments of 50 and 200 mM NaCl in a concentration-dependent manner, and in Sanghaehyanghyella it rather increased slightly at 50 mM but decreased drastically at 200 mM. Comparably, IR29, a salt-sensitive cultivar, showed a reduction of the Os-Bil gene expression after the treatment of 100 mM NaCl, but Pokkali, a salt-tolerance cultivar, rather increased about two times in the level of Os-Bil transcripts. These results suggest that the BPH resistance gene may involve in the difference in the salt-tolerance at least between the two indica rice cultivars.

Growth Response and Changes of Nitrate and Sucrose Content in Tomato under Salt Stress Condition (염스트레스에 의한 토마토 생장반응과 식물체내 Nitrate 및 Sucrose 변화)

  • Lee, Ju-Young;Jang, Byoung-Choon;Lee, Su-Yeon;Park, Jae-Hong;Choi, Geun-Hyoung;Kim, Sam-Cwaun;Kim, Tae-Wan
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.3
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    • pp.164-169
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    • 2008
  • This experiment was carried out to find the growth response and changes of nitrate and soluble sugar content in tomato leaves with salt stress. Tomato (Solanum lycopericum) seedlings were grown under different electrical conductivity (EC) levels adjusted with $CaCl_2$ as 1, 2, and $6dS\;m^{-1}$. The growth response and contents of nitrate and soluble sugar in tomato plants were examined at 7 and 14 days after salt treatment. Leaf area and dry weight ratio of shoot to root of tomato plants were decreased as EC level increased. Photosynthetic rate of leaves was reduced under high EC level due to the stomatal closure and the reduction of transpiration rate. The soluble sugar and starch content were lower in the tomato leaves grown under high EC level. Total nitrogen and nitrate contents were decreased in high EC level, whereas the ammonium content was increased. High-salt stress induced the accumulation of salt crystal in mesophyll cells of tomato leaf.

Enhancement of L-lysine Productivity by Strain Improvement and Optimization of Fermentation Conditions in Corynebacterium glutamicum (Corynebacterium glutamicum 균주 개량 및 발효 공정 최적화에 의한 L-lysine 생산성 증진)

  • Seo, Jin-Mi;Hyun, Hyung-Hwan
    • KSBB Journal
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    • v.21 no.2
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    • pp.79-84
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    • 2006
  • In order to minimize the reduction of lysine productivity by accumulation of lysine and byproducts in the end of fed-batch fermentations, a salt-tolerant mutant C14-49-3-15-7-3-20, which could grow at high concentrations of NaCl was isolated through mutagenesis from the Corynebacterium glutamicum mother strain I. In the evaluation of L-lysine productivity by fed-batch fermentations using a 5 L jar fermenter, the salt-tolerant mutant strain C14-49-3-15-7-3-20 produced 130.6 g/L of L-lysine with a 48.6% of yield. The mother strain I produced L-lysine concentration only 104.9 g/L with a yield 41.8%, implying the improvement of L-lysine productivity by introduction of salt-tolerance character.

Effect of Repeated Wet/Dry Cycles of Salt Solution on Flexural Performance of Steel Fiber Reinforced Concrete (반복적 염수침지가 강섬유 혼입 콘크리트의 휨성능에 미치는 영향)

  • Kim, Ji-Hyun;Choi, Yu-Jin;Chung, Chul-Woo
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.6
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    • pp.553-564
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    • 2022
  • Concrete is a representative composite material that shows excellent performance in the construction field. However, it is a brittle and nonhomogeneous material and exhibits weak behavior against bending and tensile forces. To compensate for such weakens, fiber reinforcement has been utilized, and steel fiber has been recognized as one of the best material for such purpose. However, steel fiber can seriously affect the durability of concrete exposed to the marine environment due to the corrosion caused by chlorine ions. This study intended to evaluate the mechanical performance of steel fiber reinforce concrete during and after repeated wet/dry cycles in salt solution. According to the experimental results, there was no reduction in the relative dynamic modulus of concrete during the repeated wet/dry cycles in salt solution for 37 weeks. Flexural strength was not decreased after completion of repeated wet/dry cycles in salt solution. There was no sign of corrosion in steel fibers after visual observation of fractured surface. However, the flexural toughness was decreased, and this is because about half of the concrete specimen showed failure before reaching the maximum displacement of 3 mm. Although repeated wet/dry cycles in salt solution did not cause cracks in concrete through corrosion of steel fibers, specific attention is required because it can reduce flexural toughness of steel fiber reinforced concrete.