• Journal of the Korean Chemical Society
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• v.46 no.5
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• pp.444-456
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• 2002

To protect the occurrence of the oxidation of car body, we developed antioxidizing device made with sacrificial anode. Because car body is made of iron and iron-alloy and oxidation potential of Mg, Al and Zn is higher than that of iron, sacrificial anodes were made with Mg, Al and Zn. Accordingly, Mg, Al and Zn are better oxidizing than car body, iron and iron-alloy can be protected from oxidizing. We have made an antioxidizing device and evaluated their anti-corrosive effect for iron piece in the solution of hydrochloric, nitric and sulfuric acid using balance, SEM and XPS. When iron pieces were connected with antioxidizing device of car body, weight loss by oxidation was remarkably reduced and surface corrosion of iron piece was protected. It was shown that the surface of iron pieces which is not con-nected to the device was changed to iron(Ⅲ) oxide, Fe$_2$O$_3$. Therefore, if this device is attached to car body, corrosion and oxidation of car body will be reduced, considerably.

• Journal of Nutrition and Health
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• v.29 no.8
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• pp.861-866
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• 1996

Tannins in plant foods and beverages may produce antinutritional or toxic effects although some proteins with high affinity for tannins seem to function as defense mechanism to tannin toxicity. Our objectives were to investigate of tea tannins, iron and protein and to evaluate the role of proteins in tannin effects on iron solubility. Iron solubility in vitro was measured using tea with and without proteins. Mixtures of tea, protein in varying concentrations(either gelatin or bovine serum albumin), and iron(eithe 10 or 50ug/mL) were prepared. Controls contained water in place of tea. Iron bioavailability was assessed by measuring iron solubility in the simulated gastric condition with pepsin digestion. Bound iron was removed by centrifugation and soluble in tea alone. When iron concentratin was 10ug/mL, addition of small amounts of protein to tea dramatically reduced iron solubility, but solubility of iron increased in the tea mixturea as the concentration of protein was increased. The percnetage of iron that precipitated was much greater at 10ug Fe/mL than the values at 50ug Fe/mL suggesting that the iron binding sites on the tea-protein complex was saturated. These results suggest that interactions of iron with tea tannins are influenced by the concentratins of protein and iron.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.807-810
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• 2008

Permeable reactive barriers containing Zero-valent iron (ZVI) are used to purify ground-water contaminants. One of the representative contaminant is trichloroethylene (TCE). ZVI can act as a reducing agent of TCE. When ZVI is oxidized to Ferric iron, TCE reduced to Ethene, which is non-harmful matter. As a ZVI becomes ferric iron, the reducing effect decreases and iron becomes unavailable. So, constant reduction of TCE requires the regular supply of reducing agent. So, we use Iron-reducing bacteria(IRB) to extend the TCE degrading ability. We perform three experiment DI water, DI water with medium, and DI water with medium and IRB. By the experiment we try to found the dissolve ability.

• Korean Journal of Materials Research
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• v.16 no.8
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• pp.497-502
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• 2006

Recently, many attention have been focused on illite as a material for the well-being industry. Illite contains various kinds of iron bearing materials and they restrict their usage. In this study, Fe impurities in the illite produced in Yeongdong-gun, Chungcheongbuk-do were characterized and their removal experiments were performed. According to the characterization of illite raw ore, it contained 1.54 wt.%$Fe_2O_3$ due to the existence of iron oxide($Fe_2O_3$) and pyrite($FeS_2$). The raw ore was crushed into 3 mm or less using cone crusher and then ground by rod mill for the liberation of impurity mineral. For the removal of iron bearing minerals, an acid treatment, a flotation, a magnetic separation, and a flotation combined with magnetic separator were performed respectively. When the illite raw ore was treated with magnetic separation and various kinds of acid, 1.54wt.%. $Fe_2O_3$ content was reduced to 0.78 and 1.0 wt.%, respectively. On the other hand $Fe_2O_3$ content was reduced to be 0.52 wt.% after flotation. These results indicate that iron bearing minerals cannot be reduced below 0.3wt.%$Fe_2O_3$. However, combination of magnetic separation and flotation enable us to get 0.24wt.% of illite concentrate. It is concluded that, for the refinement of illite from Yeongdong-gun, the flotation combined with magnetic separation is good for high purity illite.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.218-225
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• 2007

A lactic acid bacterium capable of anaerobic respiration was isolated from soil with ferric iron-containing glucose basal medium and identified as L. garvieae by using 16S rDNA sequence homology. The isolate reduced ferric iron, nitrate, and fumarate to ferrous iron, nitrite, and succinate, respectively, under anaerobic $N_2$ atmosphere. Growth of the isolate was increased about 30-39% in glucose basal medium containing nitrate and fumarate, but not in the medium containing ferric iron. Specifically, metabolic reduction of nitrate and fumarate is thought to be controlled by the specific genes fnr, encoding FNR-like protein, and nir, regulating fumarate-nitrate reductase. Reduction activity of ferric iron by the isolate was estimated physiologically, enzymologically, and electrochemically. The results obtained led us to propose that the isolate metabolized nitrate and fumarate as an electron acceptor and has specific enzymes capable of reducing ferric iron in coupling with anaerobic respiration.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.107-110
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• 2003

Reduction of nitrate by zero valent iron (Fe$^{0}$ ) has been previously studied, but the proper treatment for the by-product of ammonium has not been reported. However, in terms of nitrogen contamination, ammonium may be regarded as another form of nitrogen contaminants since it can be oxidized to nitrate again under aerobic conditions. This study is focused on simultaneous removal of nitrate and its by-product of ammonium, with the ZanF (Zeolite anchored Fe), a product derived from zeolite modified by Fe(II) chloride followed by reduction with sodium borohydride. Batch experiments were performed without buffer at two different pH condition with ZanF, iron filing, Fe(II)-sorbed zeolite, and pure zeolite to estimate the nitrate reduction and the ammonium production. At higher pH, removal rate of nitrate was reduced in both ZanF and iron filings. ZnF removed 60 % of nitrate at initial pH of 3.3 with no production of ammonium, while iron filing showed equivalent production of ammonium to the reduced amount of nitrate. In terms of nitrogen contamination, ZanF removed about 60 % and 40 % at initial pH of 3.3 and 6, respectively, while iron filing presented negligible removal against total nitrogen including nitrate and ammonium.

• 연구논문집
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• s.28
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• pp.219-227
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• 1998

In order to investigate the interfacial structure between TiN and iron nitride, an AISI 4140 steel was nitrided to form a layer of thickness 15$\mum$ by DC ion nitriding, then the surface was bombarded with Ti ions and subsequently coated a TiN film of 5$\mum$ by arc ion plating method. The interfacial microstructure between TiN and iron nitride was characterized by optical microscope, SEM and XRD. So called black layer was observed in the duplex treatment. It was resulted from the decomposition of iron nitride during the bombardment. Its thickness was increased with increasing bombardment time at high bias voltage. But the thickness was greatly decreased when the iron nitride was bombarded with a nitrogen gas or at a reduced bias voltage. The adhesion strength of the top TiN coating was decreased with increasing thickness of the black layer. Furthermore, the reduced adhesion strength in this system was discussed in view of the interfacial structural relationship between TiN and iron nitride.

• Korean Journal of Materials Research
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• v.16 no.11
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• pp.687-691
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• 2006

Synthesis of Iron oxides by air oxidation of $FeSO_4$ solutions in the presence of NaOH, Diethylenetriamine (DETA), Butylamine (BA) and influence of ultrasonic wave were investigated by XRD, SEM and particle size analyzer. As the DETA addition increased to 0.05 mol, $Fe_3O_4$ was formed with goethite($\alpha$- FeOOH) and $Fe_3O_4$ single phase was formed above 0.18mol of DETA. As the BA addition increased, the XRD peak intensity of (020) face of lepidocrocite($\gamma$-FeOOH) was developed until the formation of $Fe_3O_4$ and reduced the size of the iron oxide particles formed. Ultrasonic wave reduced the size of the iron oxide particles but gave little effects on the iron oxide particles synthesized by amine.

• Animal cells and systems
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• v.8 no.2
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• pp.97-103
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• 2004

The cytotoxic effect of iron was examined in peritoneal macrophage to determine contributing factors by iron injection to rat. Viability was reduced by 24% by the iron-overload and by 30% by short-term iron addition. Total iron was increased by 45% in the iron-overloaded with remarkable elevation (9 to 14 fold) in the presence of $FeSO_4$. Free calcium was also increased by 19% in control and 44% in iron-overloaded group due to additional $FeSO_4$ NO and MDA were increased by 40% and 136%, respectively, with significant reduction (37%) of NAD(P)H. RCR and cytochrome c oxidase activity were lowered approximately by 10% with reduction of mitochondrial membrane potential. Addition of iron was frequently associated with altered distribution of mitochondria of high membrane potential in the iron-overloaded macrophage. These results suggest altered mitochondria with high NO and low NAD(P)H due to iron.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.393-400
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• 1999

The surface characteristics of nitrogen ion implanted iron aluminides were investigated using various electrochemical methods in $H_2$$SO_4$+KSCN and HCl solutions. Nitrogen ion implantation was performed with doses of $3.0$\times$10^{17}$ /ions/$\textrm{cm}^2$ at an energy of 150keV. Nitrogen ion implanted iron aluminides increased the corrosion potential and significantly decreased grain boundary activation, the active current density, and passive current density. Nitrogen implanted iron aluminides with Mo increased the corrosion, pitting potential, repassivation potential and │$E_{pit}$-$E_{corr}$│ value. Whereas, implanted iron aluminides containing boron reduced the pitting and repassivation potential in comparison with nitrogen implanted iron aluminides with Cr and Mo.o.