• Title/Summary/Keyword: ferrous iron

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The Changing Patterns of Demand-Supply and Role of Mineral Resources in Economic Growth during Industrialization of the Republic of Korea (한국공업화과정(韓國工業化過程)에서의 광물자원(鑛物資源)의 수급구조변화(需給構造變化)와 경제성장(經濟成長)에 있어서의 역할(役割))

  • Yun, Suckew
    • Economic and Environmental Geology
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    • v.18 no.1
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    • pp.65-92
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    • 1985
  • A total of 12 mineral commodities significant in domestic output, economy and/or strategy of the Republic of Korea are chosen to examine the structural changes in production and demand-supply of these minerals during the last two decades of her industrialization. These include iron and manganese ores as the raw materials for iron and steel making, copper, zinc and tungsten ores among other non-ferrous metallic minerals, limestone (cement), kaolin, talc, pyrophyllite and graphite among other non-metallic minerals, and anthracite coal as the only domestic source of fossil energy. These are reviewed historically in time-series based on the statistical data which are tabulated and graphed in terms of domestic output, export, import, apparent demand-supply, its increasing rate, and self-sufficiency rate of each commodity. The increasing rates of demand-supply (IRDS) of some more important commodities are compared with those of Gross Domestic Production (GDP) and Economic Growth Rate (EGR) to evaluate how the IRDS contributed to the GDP and EGR. The major results revealed are as follows: Among the 12 commodities, the domestic output of 8 commodities appeared to have grown with steady upward trends: they are ores of lead, zinc and tungsten, limestone (cement), kaolin, talc, pyrophyllite and anthracite coal. Two commodities, ores of iron and copper, continued with unchanging or slightly declining trends and varied fluctuations, in spite of their cardinal importance to the heavy industry and strategy of Korea. The remaining two, graphite and manganese ore, have gradualy declined in domestic output in which the former has still enough resource potential but the latter has not and virtually ceased its domestic output. Trade patterns for mineral commodities in the Republic of Korea during the last two decades have changed greatly, being marked by a shift from mineral-exporting to mineral importing, mainly because of increasing consumption of mineral raw materials for industrialization rather than beceuse of decreasing output of domestic mineral commodities in quantity. In terms of trade patterns, the 12 commodities concerned in this study can be classified into the following four groups. The 1st group - ores of lead and tungsten have only been exported without imports. The 2nd group - amorphous graphite, and pyrophyllite have mainly been exported but partly been imported. The 3rd group - kaolin, talc and crystalline graphite have equally been exported and imported, but quantity of imports have rapidly been increased with time. The 4th group - ores of iron, manganese and zinc have shifted from exports to imports during the industrialization, particularly owing to the initiation of iron and steel making by the Pohang Iron and Steel Company in the middle 1970' s and the new establishment of the Onsan Zinc Refinery in the late 1970' s. All of the 12 commodities under considerations were far above 100% in self-sufficiency rate before or in the early 1960' s. Recently, however, most of them have been declined to below 100% except for those of limestone (cement) and pyrophyllite. It is particularly serious to identify that the self-sufficiency rates of the three important metallic minerals, iron, copper and manganese ores in 1982 appeared to be 5.1%, 0.5%, and 0.01%, respectively. The average self-sufficiency rate of the total domestic minerals produced in 1982 was 14.4% (in value) for that year. Mining industry appeared to be extremely high in its intermediate demand rate whereas its intermediate input rate to be quite low indicating that mineral raw materials have been exerted strong forward linkage effects upon the other industries rather than backward linkage effects. In comparing the curves of increasing rates of demand-supply of several major minerals - iron ore, manganese ore, copper ore, limestone (cement), kaolin, and anthracite coal - with those of Gross Domestic Production and Economic Growth Rate drawn on every graph, it is clearly shown that the curves of increasing rates of demand-supply comprise around 6 to 7 periods of cycles which roughly harmonious with those of the curves of GDP and EGR, except for the curve of anthracite coal of which the configuration seems to have resulted from the (artificial) government's mineral policy rather than from economic free market mechanism. The harmonic feature of these curves well suggests that the increasing rates of demand-supply of major minerals have been significantly contributed to the GDP and EGR. In addition, the wider amplitudes of the iron, manganese and copper curves than those of the limestone (cement) and kaolin curves indicate that the contribution of the former, metallic commodities, has been greater than that of the latter, non-metallic commodities.

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Antioxidant Activity of Some Yogurt Starter Cultures

  • Kim, H.S.;Chae, H.S.;Jeong, S.G.;Ham, J.S.;Im, S.K.;Ahn, C.N.;Lee, J.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.2
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    • pp.255-258
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    • 2005
  • Several commercial yogurt starter cultures (L. acidophilus LA5, L. casei 01, L. acidophilus LA100, L. bulgaricus LB207 and L. rhamnosus GG744) were investigated for antioxidant activity by using in vitro assays. From the results of the present work, all strains tested showed varying degrees of antioxidant activity. L. bulgaricus LB207 showed the highest antioxidant activity, with a linoleic acid peroxidation inhibition of 81.3%. Hydroxy radical scavenging activity, ferrous iron chelating activity, reducing power and superoxide dismutase (SOD) activity were also studied. L. bulgaricus LB207 showed the highest hydroxy radical scavenging activity and L. casei 01 showed the highest chelating activity. L. bulgaricus LB207 and L. acidophilus LA100 showed good reducing power. All the strains in this study showed low SOD activity. The results of the present work suggest that antioxidant activity of L. bulgaricus LB207 due to its strong hydroxy radical scavenging activity and reducing power.

Characteristics of Protein Foam Agent by Stabilizer on the Ship Fire Extinguishment (선박화재 적용 단백포 소화약제의 안정제에 따른 소화특성)

  • Lee, Eungwoo;Shin, Changsub
    • Journal of the Korean Society of Safety
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    • v.30 no.4
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    • pp.79-85
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    • 2015
  • Onboard fire extinguishing system is important to protect cargo and human lives and every oil tanker has foam type fire extinguishing system. Because of environmental problem, agent which contains materials such as Perfluorinated compounds are regulated and the development of the environmental friendly agent is required. The protein foam has less environmental pollution problem and has an excellent fire extinguish performance to oil fire. In the research, bivalency metal salts were added as stabilizer to increase fire resistance and stability of the foam. Ferrous sulfate, Iron chloride and Nickel chloride were used and to adjust to vessel, sea water was applied. As a stabilizer increased, the expansion ratio was raised. However 25% drainage time was decreased over 2.0 wt.% which is knowable that the foam brokes easily. The amount of generated foam was measured to check fluidity of foam and it appeared that when $FeSO_4$ 1.2 wt.% was added, the amount of generated foam reached large and also the 25% drainage time was high. To evaluate the fire extinguishing performance for oil fire, the small scale oil fire test was executed. When $FeSO_4$ 1.2 wt.% was added, fire extinguishing time was in its shortest which informs fluidity of foam and stability are important factors on fire extinguishing efficiency.

Effects of Jwagyuyeum and Woogyuyeum on Free Radical Generating Enzyme Activities and Lipid Peroxidation in Rat's Kidney (흰쥐의 신(腎)에서 과산화지질(過酸化脂質) 생성(生成) 및 Oxygen Free radical 생성계(生成系) 효소(酵素) 활성(活性)에 미치는 좌귀음(左歸飮)과 우귀음(右歸飮)의 영향(影響))

  • Yoon, Cheol-Ho;Jeong, Ji-Cheon;Shin, Uk-Seob
    • The Journal of Internal Korean Medicine
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    • v.17 no.1
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    • pp.265-277
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    • 1996
  • Jwagyuyeum and Woogyuyeum, being known to reinforce Kidney-yin and -yang, were tested for the effects of on free radical generating enzyme and lipid peroxidation in rat's kidney. In vitro, levels of lipid peroxide in tissues of brain were proportionally decreased to concentration of extracts prepared from Jwagyuyeum and Woogyuyeum. They were much more decreased, when lipid peroxidation was induced with ferrous iron (Fe+2), In vivo, after both herbs were administered to the rat, levels of lipid peroxide in kidney were decreased only in Jwagyuyeum. The enzyme activities and the ratio of type conversion of xanthine oxidase were decreased only in Jwagyuyeum. But, We can't see special changes in Woogyuyeum. The enzyme activities of aldehyde oxidase was lowered in both herbs, especially Jwagyuyeum was much more done. These results suggest that Jwagyuyeum and Woogyuyeum decrease the activities of free radical generating enzymes such as xanthine oxidase and aldehyde oxidase which form lipid peroxide.

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Assessment of Field Applicability of a Zero Discharge and Reuse System (무방류 재이용 시스템 현장 적용성 평가)

  • Cho, Kyung-Sook;Lee, Kwang-Ya
    • Current Research on Agriculture and Life Sciences
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    • v.29
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    • pp.75-81
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    • 2011
  • This study performed field examinations of a zero discharge and reuse system developed by Hong and Choi(2009). The system installed one of villages located in Hyoryeong-myeon, Gunwee-gun for the experiments. The zero discharge and reuse system consists of anoxic, FES (Ferrous Electricity System), Oxic, Cralifier processes for water treatments. The main feature of the system is to remove phosphorous by using Fe-ionizing module within the FES process. The water purification performances of the system were evaluated, while any defects for using the system were investigated through the field monitoring. It was found that the removal capacities of T-P, T-N, and BOD of the system meet the required water quality with outstanding performance from T-P by obtaining the results of over 90 % removal rates. The efficiency of T-P removal rate of the system found to be greatly influenced by whether using an automatic washing system to the Fe-ionizing module and conducting replacement of iron plate within a proper period.

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Characterization of Naphthalene-Degrading Pseudomonas Species Isolated from Pollutant-Contaminated Sites: Oxidative Stress During their Growth on Naphthalene

  • Kang, Yoon-Suk;Kim, Young-Jun;Jeon, Che-Ok;Park, Woo-Jun
    • Journal of Microbiology and Biotechnology
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    • v.16 no.11
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    • pp.1819-1825
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    • 2006
  • Four naphthalene-degrading bacteria (Pseudomonas sp. strains O1, W1, As1, and G1) were isolated feom pollutant-contaminated sites. Examination of their substrate utilization and analyses of key naphthalene-catabolic regulatory genes revealed that the pathway and regulation of naphthalene-degradation in all four strains resemble those of NAH7 from P. putida G7. Superoxide anion production, superoxide dismutase activity, and catalase activity during their growth on naphthalene-amended medium increased significantly, compared with those with glucose-amended medium. Addition of ascorbate, an antioxidant, or ferrous iron ($Fe^{2+}$) increased the growth rates of all tested microorganisms on naphthalene. Northern blot and HPLC analyses showed that both nahA gene expression and naphthalene degradation increased under those conditions. Our data suggest that naphthalene degradation can impose severe oxidative stress, and defenses against oxidative stress would play an important role in the metabolism of naphthalene.

Recovery of Gallium from Steelmaking Dust (제강더스트로부터 갈륨의 회수)

  • 양종규;이성식;김종화;황영길
    • Resources Recycling
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    • v.2 no.4
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    • pp.27-32
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    • 1993
  • A process has been studied to recover gallium from steelmaking dust which had several hundreds ppm of gallium. Aqueous solution containing 38 mg/l gallium was obtained by leaching of dust with 2.25 mol/l sulfuric acid. The leach liquor contained iron and zinc about 1,000 times greater than gallium. Gallium was then concentrated by ion exchanger of chelating resin with functional group of amino carboxylic acid after reduction of ferric ion to ferrous ion and pH adjustment. Gallium was concentrated to be 13 g/l in the resulting eluate by double ion exchanges. The liquor was further treated to remove impurities by solvent extraction technique empolying TOMAC as extractant. The galluim with 99% purity was finally obtainable.

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Effects of Jwagyuyeum and Woogyuyeum on Free Radical Generating Enzyme Activities and Lipid Peroxidation in Senile Rat's Liver (좌귀음(左歸飮)과 우귀음(右歸飮)이 노화(老化) Rat의 간(肝) 과산화(過酸化) 지질(脂質) 생성(生成) 및 활성산소(活性酸素) 생성계(生成系) 효소(酵素) 활성(活性)에 미치는 영향(影響))

  • Yoon, Cheol-Ho;Jeong, Ji-Cheon
    • The Journal of Internal Korean Medicine
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    • v.16 no.1
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    • pp.62-80
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    • 1995
  • Jwagyuyeum and Woogyuyeum, being known to reinforce Kidney-yin and -yang, were tested for the effects of on free-radical generating enzyme and lipid peroxidation. In vitro, levels of lipid peroxide in tissues of liver were proportionally decreased to concentration of extracts prepared from Jwagyuyeum and Woogyuyeum. They were much more decreased, when lipid peroxidation was induced with ferrous iron (Fe+2). In vivo, after both herbs were administered to the rat, levels of lipid peroxide in liver were decreased only in Jwagyuyeum. And, enzyme activities of xanthine oxidase and aldehyde oxidase in liver were not changed. It was guessed that Jwagyuyeum and Woogyuyeum inhibited lipid peroxidation directly, or acted on free radical resolving enzymes which decrease lipid peroxide. Consequently both herbs, particularly in Jwagyuyeum might delay aging.

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Effects of Organic Materials on Soil Chemical Properties (유기물(有機物)의 시용(施用)이 토양(土壤)의 화학적(化學的) 성질(性質)에 미치는 영향(影響))

  • Oh, Wang-Keun
    • Korean Journal of Soil Science and Fertilizer
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    • v.11 no.3
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    • pp.161-174
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    • 1979
  • A review was made on the effect of organic matter application on the chemical characteristics of soils such as pH, solubilities of minerals, and cation exchange capacity mainly at flooded rice soils. The review can be summarized as follows: 1. Application of organic material such as rice straw and compost in flooded rice soil leads to a temporary lowering of soil pH at the earlier stage of soil reduction, due to the production of various organic acids and carbonic acid. This temporary lowered pH is replaced with the production of alkaline substances such as ammonia as the reduction of soil proceeds. 2. Incorporation of organic materials intensifies the ferrous iron, dissolving various minerals, virtually to the increase in electrical conductivity of soils. 3. Organic materials also play an important role in dissolving soil minerals through the production of various chelating agents. 4. Application of soil organic matter significantly increases cation exchange capacity of soils. 5. Continuous application of rice straw or compost leads to the increase in soil organic matter content to some extent, up to the level of equilibrium. In soils low in organic matter the equilibrium level is attained with five years continuous application of compost. 6. The manner of chemical fertilizer application influences the accumulation of organic matter applied in soils. Low levels of fertilization lowers the accumulation while high levels of fertilization accerelates the accumulation.

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Antioxidant Activity and Tolerance to Reactive Oxygen Species of Lactobacillus spp. (Lactobacill spp. 의 황산화 효과 및 활성산소에 대한 내성)

  • Kim, H.S.;Jeong, S.G.;Chae, H.S.;Ham, J.S.;Ahn, C.N.;Lee, J.M.
    • Journal of Animal Science and Technology
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    • v.46 no.6
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    • pp.1007-1012
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    • 2004
  • The four Lactobacillus spp. were investigated for their antioxidant properties, including antioxidant activity, tolerance to reactive oxygen species, hydroxy radical scavenging activity and ferrous iron che1ating activity. Also, activities of superoxide dismutase and glutathione peroxidase were investigated. From the results of this work, the intact cell and cell lysate of L. casei KCTC 3260 were exhibited highest antioxidant activity. L. casei KCTC 3260 also showed strong tolerance to reactive oxygen species. This strain showed highest glutathione peroxidase activity among the tested strains.