• 한국세라믹학회지
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• 제18권2호
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• pp.105-111
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• 1981

The iron precipitates were prepared by adding sodium carbonate solution to ferrous chloride and ferric chloride solutions to pH=9 and pH=4.5, respectively. The thermal reaction of the iron precipitates was investigated by means of TGA, DTA and X-ray diffraction. In the former the crystallization of $\alpha$-$Fe_2O_3$ begins at about 35$0^{\circ}C$, while in the latter at about 30$0^{\circ}C$, during the calclnation in air. In the iron precipitate from ferrous chloride solution, the activation energy for the crystallite-growth or $\alpha$-TEX>$Fe_2O_3$ in air is about 7.6$\times$104J/mole between 800 and 100$0^{\circ}C$. As the result of X-ray diffration for the reduction product of hematite, it was found that maghemite, magnetite and wustite are formed and that hematite is transformed to magnetite through maghemite.

• 미생물학회지
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• 제10권1호
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• pp.1-8
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• 1972

This experiment was carried out to investigate the physiological characteristics of isolated bacteria, Ferrobacillus ferooxidans from copper mine water in Korea. The results obtained were as follows ; 1. The optimum pH range for the growth of these bacteria was 2.0-3.0 and optimum temperature was $20^{\circ}C$-$30^{\circ}C$. 2. The oxidation curves of ferrous iron to the ferric iron ran parallel with the growth curves. 3. The optimum nitrogen concentration was 400-800 ppm and the minimal flow rate of air for the maximal growth of the bactria was 70 ml air/min./200ml medium. 4. The growth of these bacteria was inhibited by the absence of ferrous iron and by the addition of sulfur. 5. Ferrous iron at a concentration of 9000 ppm, appeared to be optimum for the most rapid growth of Ferrobacillus ferrooxidans.

• Advances in concrete construction
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• 제6권5호
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• pp.545-560
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• 2018

The ever-increasing cost of natural sand and the environmental impacts of extracting manufactured sand (quarry sand) calls for exploring the potential to use alternative materials as fine aggregates in concrete. Copper slag and ferrous slag are industrial by products obtained from the smelting process of copper and iron respectively. A large quantity of copper slag and ferrous slag end up being disposed as waste in landfills and this poses a serious threat to the environment. Copper slag and ferrous slag have similar physical and chemical properties as natural sand and also exhibit pozzolanic activity. This paper studies the technical feasibility of industrial by-products such as copper slag and ferrous slag to replace the fine aggregate in concrete by evaluating the workability, strength and durability characteristics of concrete. The test results indicate that the strength properties are not affected by 40% or 100% replacement of quarry sand with iron slag or copper slag. However, 40% replacement of quarry sand with iron slag or copper slag in concrete is recommended considering the durability aspects of concrete.

• 한국기계가공학회지
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• 제2권1호
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• pp.39-44
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• 2003

In the present industry, there are necessary to cut not only iron metals but also non-ferrous metals such as aluminum, brass, plastic and wood(Paulownia) therefore it had been made the studies of non-ferrous metals by many scientists. The purpose of this study is to conduct the basic experiment about influencing of the feedrate adjustment and the change of the side rake angle at turning of non-ferrous metals. As the results, the surface roughnesses and Cutting force adjustments were on the decrease with a side-rake angle and feedrate diminution in the case of the plastic, brass, aluminum, and paulownia.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.929-934
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• 1997

In the present industry, there are necessary to cut not only iron metals but also non-ferrous metals such as aluminum, brass, plastic and wood(Paulownia).therefore it had been made the studies of non-ferrous metals by many scientists. we hope this kind of study will continue. The purpose of this study is to conduct the basic experiment about influencing of the feedrate adjustment and the change of the side rake angle at turning of non-ferrous metals. As the results, the surface roughnesses and Cutting force adjustments were on the decrease with a side-rake angle and feedrate diminution in the case of the plastic, brass, aluminum, and paulownia

• 한국식품과학회지
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• 제19권1호
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• pp.23-28
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• 1987

Silicic acid chromatography로 순수정제한 대두유 의 향미안정성에 미치는 인지방질의 영향을 조사하였다. 1ppm ferrous iron을 첨가한 순수정제 대두유에 300ppm 의 phosphatidyl choline(PC), phosphatidyl ethanolamine(PE), phosphatidyl inositol(Pl), phosphatidic acid(PA), phosphatidyl glycerol(PC), cardiolipin(CL)을 개별적으로 첨가하여 $60^{\circ}C$의 오븐에서 10일간 저장한후, 시료병 윗 공간내의 총휘발성물질양 및 산소의 잔유량으로써 향미안정성을 측정하였다. 1ppm의 철분을 함유한 시료의 향미안정성은 인지방질을 첨가함으로써 개선되었는데, 이는 인지방질의 금속이온에 대한 chelating효과에 기인한 것으로써, PA. PE, PC, PG, CL, Pl의 순으로 효과적이었다. 그러나 철분을 함유하지 않은 순수정제 대두유에 인지방질을 첨가했을 경우, 그 향미안정성은 감소하였다. 즉 금속 이온이 없을 경우 인지방질은 산화촉진효과를 나타내었는데, 이는 인지방질의 극성부분으로 인하여, 유지의 계면에 용존산소의 농도가 증가하는 데에서 기인하는 것으로 생각한다. 그러므로, 유지의 향미안정성을 개선시키기 위하여는 유지내 인지방질의 농도를 금속이온을 chelating시킬 적당량만을 유지하는 것이 바람직한 것으로 생각된다.

• Applied Biological Chemistry
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• 제14권3호
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• pp.177-182
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• 1971

0.02M EDTA-2Na와 $Na_2S_2O_4$에 의한 벼잎의 철을 분별정량하는 새방법을 적고이병잎을 사용검정하였다. 1) 시도한 방법은 환원철($Fe^{++}$), 산화철($Fe^{+++}$), 침전철(PFe) 및 결합철(BFe)로 분별 정량할 수 있고 식물조직의 생리적상태를 잘 나타내었다. 2) 생리적으로 가장 알맞은 철풀의 패턴은 $Fe^{+++}>PFe>BFe>Fe^{++}$이고 보통인 때 $PFe>Fe^{+++}>BFe>Fe^{++}$이고 부적합한 때 $BFe>Fe^{+++}>PFe>Fe^{++}$이며 독작용이 있을 경우 $BPe>PFe>Fe^{+++}>Fe^{++}$임이 추정된다. 3) 전철에 대한 각철의 백분율은 환원철이 10이하 산화철과 침전철이 $20{\sim}40$이며 결합철은 $20{\sim}50$이었다. 4) 잎의 상부가 하반부에 비해 불건전한 증상임에도 언제나 환원철이 많은 것은 상반부에 환원철이 크게 관여하는 활동적 대사계가 있는 것을 의미한다.

• 한국재료학회지
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• 제20권6호
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• pp.301-306
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• 2010

The chemical formula of magnetite ($Fe_3O_4$) is $FeO{\cdot}Fe_2O_3$, t magnetite being composed of divalent ferrous ion and trivalent ferric ion. In this study, the influence of the coexistence of ferrous and ferric ion on the formation of iron oxide was investigated. The effect of the co-precipitation parameters (equivalent ratio and reaction temperature) on the formation of iron oxide was investigated using ferric sulfate, ferrous sulfate and ammonia. The equivalent ratio was varied from 0.1 to 3.0 and the reaction temperature was varied from 25 to 75. The concentration of the three starting solutions was 0.01mole. Jarosite was formed when equivalent ratios were 0.1-0.25 and jarosite, goethite, magnetite were formed when equivalent ratios were 0.25-0.6. Single-phase magnetite was formed when the equivalent ratio was above 0.65. The crystallite size and median particle size of the magnetite decreased when the equivalent ratio was increased from 0.65 to 3.0. However, the crystallite size and median particle size of the magnetite increased when the reaction temperature was increased from $25^{\circ}C$ to $75^{\circ}C$. When ferric and ferrous sulfates were used together, the synthetic conditions to get single phase magnetite became simpler than when ferrous sulfate was used alone because of the co-existence of $Fe^{2+}$ and $Fe^{3+}$ in the solution.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.807-810
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• 2008

영가철(ZVI)를 사용하는 투수성 반응벽체(PRB, Permeable reactive barrier)는 TCE(Trichloroethylene)와 같은 난분해성 유기물질이 포함된 지하수를 처리하는데 사용될 수 있다. 여기서 ZVI(Zero-valent iron)가 Ferric iron으로 산화되면서 TCE를 ethene으로 환원시킨다. Ferric iron으로 변화된 iron은 환원과정을 통해 Ferrous iron으로 다시 재생을 시켜야 PRB의 처리수명을 연장시킬 수 있다. Ferric iron을 Ferrous iron으로 환원시키기 위해서 철환원 박테리아(IRB, Iron-reducing bacteria)를 이용한다. 이번 연구에서는 IRB가 Ferric iron을 환원시키기 위해서 Ferric iron을 용해를 한다는 concept으로 실험을 해보았다. 실험은 증류수(DI water, De-ionized water), DI-water에 배지를 포함한 용액, 그리고 DI-water에 배지 및 IRB가 포함된 용액, 이 3가지 조건으로 수행했다. 실험결과 $Fe^{3+}$의 용해가 IRB가 포함된 용액, 배지가 포함된 용액, 증류수 순으로 잘 되는 것으로 나타났다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.118-121
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• 2002

The kinetics and stoichiometry of the reduction of hexavalent chromium (Cr(Ⅵ)) with ferrous iron (Fe(II)) were examined in systems with and without aquifer solids. Cr(Ⅵ) reduction was rapid in the absence of solids, but demonstrated slower and more complex kinetics in the presence of aquifer solids. The aquifer solids removed Fe(II) from solution and a portion of the reducing capacity of Fe(II) was transferred to the aquifer solids. The solid phases were then able to continue to remove Cr(Ⅵ). This suggests in-situ treatment of Cr(Ⅵ) by Fe(II) injection would be feasible in the aquifer environment. In general, re-oxidation of reduced chromium by molecular oxygen was not observed in our systems over time periods of nearly one year.