• Title/Summary/Keyword: Zinc

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A Basic Study on Separation of U and Nd From LiCl-KCl-UCl3-NdCl3 System (LiCl-KCl-UCl3-NdCl3 system에서 U 및 Nd 분리에 관한 기초연구)

  • Kim, Tack-Jin;Ahn, Do-Hee;Eun, Hee-Chul;Lee, Sung-Jai
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.1
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    • pp.59-64
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    • 2018
  • In case of high contents of rare earths in the LiCl-KCl salt, it is not easy to recover U and TRU metals as a usable resource form from LiCl-KCl eutectic salts generated from the pyroprocessing of spent nuclear fuel. In this study, a conversion of $UCl_3$ into an oxide form using $K_2CO_3$ and an electrodeposition of $NdCl_3$ into a metal form in $LiCl-KCl-UCl_3-NdCl_3$ system were conducted to resolve the problem. Before conducting the conversion, experimental conditions for the conversion were determined by performing a thermodynamic equilibrium calculation. In this study, almost all of $UCl_3$ disappeared in the LiCl-KCl salt when the injection of $K_2CO_3$ reached theoretical equivalent for the conversion, and then $NdCl_3$ was effectively electrodeposited as a metal form using liquid zinc cathode. After that, the LiCl-KCl salt became transparent, and uranium oxides were precipitated to the bottom of the LiCl-KCl salt. These results will be utilized in designing a process to separate U and rare earths in LiCl-KCl salt.

Inhibitory Substance Produced by Aspergillus sp. on the Snake Venom Proteinase - Isolation of Microorganism and Biological Activities of the Inhibitor - (Aspergillus 속 균주가 생성되는 사독 Proteinase에 대한 저해물질 - 균의 분리 및 저해물질의 생물학적 작용상 -)

  • Hyun, Nam-Joo;Seu, Jung-Hwn
    • Microbiology and Biotechnology Letters
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    • v.15 no.2
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    • pp.129-134
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    • 1987
  • Aspergillus sp. (MK-24) producing a biological active substance that inhibited the venom proteinase activity was isolated from soil. The substance also inhibited the activity of trypsin and coagulation of blood, but did not inhibit papain, $\alpha$-chymotrypsin and pepsin. The substance was partially purified from culture filtrate by precipitaion with acetone, and by chromatography of DEAE-Sepadex A-50 column and Amberlite IRC-50 ion exchange. The inhibitory substance was stable in the wide pH range from 2.0 to 12.0 at 37$^{\circ}C$, but not stable at $65^{\circ}C$ in the alkaline pH. Only 12% of the activity was decreased by the heat treatment at 10$0^{\circ}C$ for two hours. The inhibition on venom proteinase (Agkistrodon bromohoffi brevicaudus) was a mixed type. The inhibitory activity depended on the preincubation time and completely depressed by cupric, zinc and cobalt ions. The inhibition on the venom proteinase was appeared strongly on casein but not on ovalbumin or hemoglobin as a substrate.

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Improvement of Hot Dip Galvanizing Process by Additive to Flux Solution (플럭스액의 첨가제에 의한 용융아연도금 공정개선)

  • Moon, Kyung-Man;Jeong, Jae-Hyun;Park, Jun-Mu;Lee, Myeong-Hoon;Baek, Tae-Sil
    • Journal of the Korean institute of surface engineering
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    • v.49 no.6
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    • pp.513-520
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    • 2016
  • Many surface protection methods have been developed to apply to constructional steels which have been used under severe corrosive environments. One of these methods, hot dip galvanizing is being widely used to the numerous constructional steels such as a guard rail of high way, various types of structural steel for manufacturing ship and for some other industrial fields etc.. Recently, the cost of zinc is getting higher and higher, thus, it is considered that improvement of hot dip galvanizing process to reduce the cost of production should be developed possibly. In this study, additives such as acid cleaning solution, $NH_4OH$, $Al(OH)_3$ and $H_2O_2$ were added to flux solution, and omission of water washing treatment after acid cleaning was investigated with some types of flux solutions added with some additives mentioned above. The decrement of pH by adding the acid cleaning solution could be controlled due to neutralization reaction with addition of $NH_4OH$. The flux solution added with both $NH_4OH$ and $Al(OH)_3$ exhibited nearly the same color and pH value as those of orignal flux solution with no added, and the sample dipped to the flux solution which was added with additives mentioned above indicated a relatively good corrosion resistance compared to other samples. However, the flux solution added with $NH_4OH$, $Al(OH)_3$ and $H_2O_2$ exhibited a different color, sediment and a bad corrosion resistance. Consequently, it is considered that omission of water washing treatment may be able to perform by adding optimum additives to the original flux solution.

Chemical Composition and Antimicrobial Activities of Houttuynia cordata Thunb. (어성초의 화학성분 및 항미생물 활성)

  • Kim, Keun-Young;Chung, Dong-Ok;Chung, Hee-Jong
    • Korean Journal of Food Science and Technology
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    • v.29 no.3
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    • pp.400-406
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    • 1997
  • Chemical composition and antimicrobial activity of Houttuynia cordata Thunb. were investigated to develop a natural food preservative from it. Aspartic acid, glutamic acid, glycine and arginine were major amino acids of Houttuynia cordata Thunb., but were present in a trace amount. Free sugars were composed of glucose, fructose, sucrose and maltose and major fatty acids were linolenic acid, linoleic acid, oleic acid, and palmitic acid. Mineral elements were potassium, calcium, magnesium, iron, zinc, and copper. Antimicrobial activities were shown in acidic, neutral and phenolic fraction of Houttuynia cordata Thunb., but not in basic fraction. Among the four fractions, neutral fraction showed the strongest antimicrobial activities against microorganisms tested, such as Pseudomnas aeruginosa, Micrococcus luteus, Bacillus subtilis, Aspergillus parasiticus and Aspergillus flavus. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of the neutral fraction varied according to microoganisms tested. The lowest values of MIC (0.0075 g eq./mL) and MLC (0.10 g eq./mL) were obtained from Pseudomonas aeruginosa.

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Effects of Dietary Zinc on the Ethanol Metabolizing Enzyme Activity and Ethanol Elimination Rate in Rat (식이성 아연이 에탄을 대사 호소활성과 에탄을 제거율에 미치는 영향)

  • Jeung, Jae-Hong;Cho, Soo-Yeul
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.17 no.3
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    • pp.269-276
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    • 1988
  • 식이성 아연이 에탄올의 생체대사율에 미치는 영향을 검토코저 흰쥐에 식이중 아연의 함량(100ppm, 5ppm)을 달리하여 성장시키면서 에탄올을 4주 및 7주간 급여한 다음, 체중증가량과 에탄올의 대사에 관여한다고 알려져 있는 alcohol dehydrogenase, microsomal ethanol oxidizing system, catalase 및 aldehyde dehydrogenase의 활성변동과 혈중 에탄올 제거율을 측정한 결과는 다음과 같다. 실험기간 중 체중증가량은 대조군에 비해 Zn이 부족한 실험군에서 감소되었으며, 에탄올을 투여한 CE군과 ZnDE군은 control에 비해 현저히 감소하였다. Zn 부족한 군(ZnD)에서의 간 ADH, MEOS의 활성 및 혈액중 에탄올 제거율이 아연이 충분히 함유된 대조군에 비해 감소하였으나, catalase와 AIDH의 활성은 별다른 차이를 관찰할 수 없었다. 한편 에탄올을 투여한 CE 및 ZnDE군에서는 대조군(C 및 ZnD)에 비하여 ADH, MEOS 및 혈액중 에탄올 제거율이 증가하였으며 그 증가율은 아연을 충분히 급여한 CE군에서 아연이 부족한 ZnDE 군에 비하여 높게 나타났다. AIDH의 활성은 에탄올의 투여에 의해 CE군에서는 증가하였으나 ZnDE군에서는 별다른 변동을 관찰할 수 없었으며 catalase의 활성은 전실험군에 있어서 차이를 발견할 수 없었다.

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Comparison of Microwave and Conventional Cooking Methods on the Nutritional Composition of Potatoes -(1) Changes of Proximate Composition, Minerals and Water-soluble Vitamins- (감자의 몇가지 영양성분(營養成分)에 대한 마이크로파(波)와 재래적(在來的) 조리방법(調理方法)의 비교(比較) -1. 일반성분(一般成分), 무기질(無機質) 및 수용성(水溶性) 비타민의 변화에 대하여-)

  • Yoo, Yang-Ja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.14 no.2
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    • pp.171-176
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    • 1985
  • The effects of cooking methods by boiling, electric oven and microwave on the proximate composition, minerals and water-soluble vitamins of two major Korean potato varieties (Soomi and Namjac) were studied. The dry matter content was increased after the cooking by the methods of electric oven and microwave, however, the crude fiber content was highly decreased by both methods. The crude ash content was not affected by the cooking methods used. The potassium content was increased by electric oven and microwave methods, and iron content was increased by electric oven baking, however, the copper content was significantly decreased by the electric oven and microwave cooking methods. The macrominerals (phosphorus, magnesium, calcium) and microminerals (zinc, manganese, nickel, lead, cadmium) content present initially in potatoes have not been changed by the cooking methods employed in this study. Relative retention value of ascorbic acid was the lowest and the value of thiamin was the highest in the potatoes cooked by microwave. The retention values of riboflavin and folic acid obtained. after boiling were similar to those after microwave cooking, and both of these treatments were superior to the electric oven baking. The retention values of niacin and vitamin $B_6$ varied between 93 and 100% depending on the cooking methods used. Overall, with a few exceptions, the retention values of water-soluble vitamins in boiled and microwave cooked potatoes were superior to those of the electric oven baked.

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Chemical Composition of Maize Germs Separated in the Manufacture of Cornstarch (옥수수전분 제조공정의 부산물인 maize germ의 지질 및 아미노산 조성)

  • Cho, Sung-Hwan;Kim, Ze-Uook;Choi, Jong-Duck
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.15 no.1
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    • pp.15-21
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    • 1986
  • This study was conducted to research the industrial utilizaion of the maize germs separated in the manufacture of the cornstarch. The maize germs contained crude protein (25.3%) and crude fat (19.2%), with the 512 Kcal/100g of determined food energy values. It was found to have the valuable amounts of essential minerals, such as the content of calcium and phosphorus were low (53.0, 12.3mg%), while those of potassium (495.4mg%), magnesium (95.0mg%), zinc (48.3ppm) and manganese (45.2ppm) were plentiful. It was noted that the iodine value was 44.0, saponification value 292.3, acid value 1.5 and peroxide value about 3.3. The lipid fractions obtained by silicic acid column chromatography were mainly composed of neutral lipid, whereas, the contents of glycolipid and phospholipid were scarcely. The major fatty acids in total lipids were linoleic $(60{\sim}62.5%)$, oleic $(20{\sim}22.5%)$ and palmitic $(10{\sim}13.5%)$ acids. The content of the unsaturated fatty acids was more predominant than that of the saturated fatty acids. The content of the insoluble proteinous nitrogen (32.5%) was the most abundant. whereas, the contents of soluble proteinous nitrogen (12.7%) and peptide proteinous nitrogen (3.3%) were low. The major amino acids of the maized germs were glutamic, glycine, alanine and aspartic. It has been identified by the SDS-disc electrophoresis that the protein of maized germs had $5{\sim}6$ bands. Compared with standard substances, the molecular weight of the main protein was estimated to be $14,500{\sim}24,500$.

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Comparative Study of Food Components and Sensory Properties of Common Porphyra yezoensis and Functional Porphyra yezoensis (일반 김과 기능성 김의 식품성분과 관능평가 비교 분석에 관한 연구)

  • Seo, Hee-Young;Jung, Bok-Mi
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.10
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    • pp.1314-1319
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    • 2007
  • This study is to compare food components and the sensory properties of common and functional Porphyra yezoensis, Pyroligneous liquor, Salicornia herbacea L. and Salicornia herbacea L. treated with oak charcoal. The samples used in this study were provided by a local manufacturer. We analyzed their proximate composition, mineral content, heavy metal content and amino acids. We conducted the sensory evaluation before and after grilling Porphyra yezoenis. Common components are more plentiful in functional Porphyra yezoenis than in common except for carbohydrate and crude fiber. In the case of mineral content, generally functional Porphyra yezoensis contains much more mineral than common except for magnesium and zinc. Especially Salicornia herbacea L. treated with oak charcoal contains abundant iron. Also, Salicornia herbacea L. contains a lot of calcium potassium, copper and sodium. There is a little more heavy metal except for chromium, cadmium and lead in Salicomia herbacea L. treated with oak charcoal than in common that contains a lot of chromium, cadmium and lead, although a wide difference was not discovered between them. In the case of composed amino acid, there are much glutamic acid, glycine, isoleucine and phenylalanine in both Porphyra yezoensis. Especially alanine and phenylalanine are trebled in functional Porphyra yezoensis. Also, there are far more serine and lysine in Salicornia herbacea L. and Salicornia herbacea L. treated with oak charcoal than in common Porphyra yezoensis and Pyroligneous liquor. In the case of the sensory properties, there isn't a big difference before grilling Porphyra yezoensis; however, after grilling, most functional Porphyra yezoenis had good sensory properties results, especially Salicornia herbacea L. were better than Pyroligneous liquor.

Effect of Contamination by the Abandoned Coal Mine Drainage on the Stream Water in Keumsan, Chungnam (금산(錦山) 폐탄광지역(廢炭鑛地域)의 오염(汚染)이 하천수(河川水)에 미치는 영향(影響))

  • Kim, Myung Hee;Min, Ell Sik;Song, Suckhwan
    • Journal of Korean Society of Forest Science
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    • v.86 no.4
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    • pp.435-442
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    • 1997
  • The research was carried out to investigate the contamination of stream water by the acid mine drainage originated from the abandoned coal mines and coal waste rock in Keumsan, Chungnam. The pH, sulfate and chemical compositions in the stream water were analyzed. At the polluted sites, the pH of stream water was the strong acid, ranging from 3.46 to 4.29. The pH shows negative correlations with sulfate, manganese, copper, zinc, iron and magnesium concentrations. Sulfate concentrations of the polluted stream water, 236.73-310.53mg/l, had 10 times more than those of the non-polluted stream water. The concentrations of heavy metals, Mn and Fe, in the polluted water were 0.56 - 0.83mg/l and 5.89 - 10.58mg/l, respectively. The Mn concentrations were 20 times higher than those of the non-polluted stream water. Compared with those in the non-polluted stream water, the Mg and Ca concentrations in the polluted stream water were high because of leaching from rock and soil to water by the acidifications. Calculated AMDI(Acid Mine Drainage Index) values are low in the polluted stream water, relative to those of the non-polluted water.

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The Effect of Additives on the Properties of Zn Electrode in Zn/AgO Secondary Battery (Zn/AgO Secondary Battery용 아연 양극의 성능에 미치는 첨가제의 영향)

  • Park, Kyung-Wha;Kim, Chang-Hwan;Moon, Kyung-Man
    • Journal of the Korean Electrochemical Society
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    • v.6 no.3
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    • pp.196-202
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    • 2003
  • We investigated the effect of both 4 types additives and $0.5wt\%\;Pb_3O_4$ which have been reported to show an improvement on the performance of Zinc anode. And Experimental methods such as corrosion potential measurement, potentiodynamic polorization test and charging-discharging cycle life test were carried out in $40 wt\%$ KOH with $Pb_3O_4(0.5, \;10\;&\;2.0wt\%)$ and 4 types additives $(0.4wt\%\;of\;Ca(OH)_2$, 0.025M of Citrate, Tartrate and Gluconate). Corrosion potential was shifted to high direction and also changed to high and low direction repeatedly with increasing of $Pb_3O_4$ quantity. However by adding $0.5wt\%\;Pb_3O_4$, corrosion potential shifted to low direction and showed stable condition. Furthermore it was well known that corrosion resistance was predominantly increased compared to no addition and improved charging-discharging property with adding additives. By SEM analysis, it was concluded that the morphology of surface in case of only $0.5wt\%\;Pb_3O_4$ addition was nearly the same as that of Tartrate additive and in the other additives such as $Ca(OH)_2$, Citrate, Tartrate and Gluconate, their morphologies showed dendrite growth. Eventually it was thought that the additive of Tartrate indicated comparatively good corrosion resistance effect as well as charging-discharging property improvement among those four types additives.