• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3295-3300
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• 2013

Acrolein (ACR) is a well-known carbonyl toxin produced by lipid peroxidation of polyunsaturated fatty acids, which is involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). In Alzheimer's brain, ACR was found to be elevated in hippocampus and temporal cortex where oxidative stress is high. In this study, we evaluated oxidative modification of cytochrome c occurring after incubation with ACR. When cytochrome c was incubated with ACR, protein aggregation increased in a dose-dependent manner. The formation of carbonyl compounds and the release of iron were obtained in ACR-treated cytochrome c. Reactive oxygen species scavengers and iron specific chelator inhibited the ACR-mediated cytochrome c modification and carbonyl compound formation. Our data demonstrate that oxidative damage of cytochrome c by ACR might induce disruption of cyotochrome c structure and iron mishandling as a contributing factor to the pathology of AD.

• Advances in materials Research
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• v.6 no.3
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• pp.245-255
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• 2017

High energy ball milling is employed to produce iron matrix- multiwall carbon nanotube (MWCNT) reinforced composite. The damage caused to MWCNT due to harsh ball milling condition and its influence on interfacial bonding is studied. Different amount of MWCNT is used to find the optimal percentage of MWCNT for avoidance of the formation of chemical reaction product at the matrix - reinforcement interface. Effect of process control agent is assessed by the use of different materials for the purpose. It is observed that ethanol as a process control agent (PCA) causes degradation of MWCNT reinforcements after milling for two hours whereas solid stearic acid used as process control agent, allows satisfactory conservation of MWCNT structure. It is further noted that at a high MWCNT content (~ 2wt.%), high energy ball milling leads to reaction of iron and carbon and forms iron carbide (cementite) at the iron-MWCNT interface. At low percentage of MWCNT, dissolution of carbon in iron takes place and the amount of reinforcement in iron matrix composite becomes negligibly small. However, under the present ball milling condition (ball to metal ratio~ 6:1 and 200 rpm vial speed) iron-1wt.% MWCNT composite of good interfacial bonding can retain the tubular structure of reinforcing MWCNT.

• Resources Recycling
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• v.23 no.3
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• pp.30-36
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• 2014

A large amount of waste copper slag containing about 35 ~ 45% iron has been generated and discarded every year from pyrometallurgical processes for producing copper from copper concentrate. Thus, recovery of iron from the waste copper slag is of great interest for comprehensive use of mineral resource and reduction of environment problems. In this study, a physico-chemical separation process for upgrading iron from the waste copper slag discharged as an industrial waste has been developed. The process first crushes the waste copper slag below 1 mm (first crushing step), followed by carbon reduction at $1225^{\circ}C$ for 90 min (carbon reduction step). And then, resulting material is again crushed to $-104{\mu}m$ (second crushing step), followed by wet magnetic separation (wet magnetic separation step). Using the developed process, a magnetic product containing more than 66 wt.% iron was obtained from the magnetic separation under a magnetic field strength of 0.2 T for the waste copper slag treated by the reduction reaction. At the same conditions, the percentage recovery of iron was over 72%. The iron rich magnetic product obtained should be used as a iron resource for making pig iron.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.04a
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• pp.62-63
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• 1999

Reduction 2,4,6-Trinitrotoluene by zero valent iron was studied in a batch reactor under anoxic conditions. Results showed that the removal of TNT was a pseudo-first order and the rate was dependent on the available metal surface area. Final product, presumably triaminotoluene, accumulated in the solution as well as on the metal surface. However, little amounts of aminodinitrotoluenes were detected. Therefore, it is postulated that the reduction of nitro group occurs simultaneously in all three position.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.496-501
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• 2005

The thermal degradation of ABS in the presence of iron-based metal catalysts has been studied by thermogravimetric analysis (TGA). The reaction of iron-based metal catalysts (ferric nitrate nonahydrate, ammonium ferric sulfate dodecahydrate, iron sulfate hydrate, ammonium ferric oxalate, iron(II) acetate, iron(II) acetylacetonate and ferric chloride) with ABS has been found to occur during the thermal degradation of ABS. In a nitrogen atmosphere, char formation was observed, and at $600^{\circ}C$ approximately 3~23 wt% of the reaction product was non-volatile char. The resulting enhancement of char formation in a nitrogen atmosphere has been primarily due to the catalytic crosslinking effect of iron-based metal catalysts. On the other hand, char formation of ABS in air at high temperature by iron-based metal catalyst was unsuccessful due to the oxidative degradation of the char.

• Advances in concrete construction
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• v.9 no.6
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• pp.589-596
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• 2020

In an effort to find alternate, environment friendly and sustainable building materials, the scope of possible utilization of iron slag (I-sand), generated as a by-product in iron and steel industries, as fine aggregates in reinforced cement concrete (RCC) made with manufactured sand (M-sand) is examined in this manuscript. Systematic investigations of the physical, mechanical, microstructural and durability properties of I-sand in comparison with RCC made with M-sand have been carried out on various mix designs prepared by the partial/full replacement of I-sand in M-sand. The experimental results clearly indicate the possibility of utilizing iron slag for preparing RCC in constructions without compromising on the property of concrete, durability and performance. This provides an alternate possibility for the effective utilization of industrial waste, which is normally disposed by delivering to landfills, in building materials which can reduce the adverse environmental effects caused by indiscriminate sand mining being carried out to meet the growing demands from construction industry and also provide an economically viable alternative by reducing the cost of concrete production.

• Journal of Magnetics
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• v.16 no.3
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• pp.294-299
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• 2011

Nd-Fe-B high performance magnets were prepared by die-upset forging. The effects of the deformation parameters on magnetic properties and flow stress were studied. Deformation temperatures in the range of $600{\sim}900^{\circ}C$ enable to achieve an effective anisotropy and temperature $800^{\circ}C$ proves to be suitable for deformation of Nd-Fe-B magnets. The amount of c-axis alignment along the press direction seems to depend on the amount of deformation and a saturation behavior is shown at deformation ratio of 75%. Magnetic properties are also related to strain rate, and maximum energy product is attained at an optimum strain rate of ${\varphi}=1{\times}10^{-2}s^{-1}$. By analyzing the relationship of stress and strain at different deformation temperature during die-upset forging process, deformation behavior of Nd-Fe-B magnets was studied and parameters for describing plastic deformation were obtained. Nd-rich boundary liquid phase, which is additionally decreasing the flow stress during deformation, is supposed to play the role of diffusion path and enhance the diffusion rate.

• Resources Recycling
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• v.16 no.3 s.77
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• pp.19-26
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• 2007

The bottom ash of municipal solid waste incineration generated during incineration of municipal solid waste in metropolitan area consists of ceramics, glasses, ferrous materials, combustible materials and food waste and so on. Although the ferrous material was separated by the magnetic separation before the incineration process, of which content accounts for about $3{\sim}11%$ in bottom ash. The formation of a $Fe_3O_4-Fe_2O_3$ double layer(similar to pure Fe) on the iron surface was found during air-annealing in the incinerator at $1000^{\circ}C$. A strong thermal shock, such as that takes place during water-cooling of bottom ash, leads to the breakdown of this oxidation layer, facilitating the degradation of ferrous metals and the formation of corrosion products and it existed as $Fe_2O_3,\;Fe_3O_4\;and\;FeS_2$. So, many problems could occur in the use of bottom ash as an aggregate substitutes in construction field. Therefore, in this study, the separation of ferrous materials from municipal solid waste incineration bottom ash was investigated. In the result, the ferrous product(such as $Fe_2O_3,\;Fe_3O_4,\;FeS_2$ and iron) by magnetic separator at 3800 gauss per total bottom ash(w/w.%) accounted for about 18.7%, and 87.7% of the ferrous product was in the size over 1.18 mm. Also the iron per total bottom ash accounted for about 3.8% and the majority of it was in the size over 1.18 mm.

• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.233-238
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• 1980

It was observed that the magnetic moment for iron in $[(DPGH)_2FeO_2Fe(DPGH)_2]$, the oxygenation product of a octahedral iron(Ⅱ) complex, $[Fe(DPGH)_2(NH_3_2]$, decreases with decreasing temperature from ${\mu}$ = 3.60 B.M (Bohr Magneton) per iron at $298^{\circ}$K down to ${\mu}$ = 1.65 B.M per iron at $4.2^{\circ}K$. This observation may be explained by a weak antiferromagnetic coupling between two iron(Ⅲ) atoms of intermediate spin state (S = 3/2) in the molecule with the coupling constant $J = -l cm^{-1}$.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.130-133
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• 2003

A method for separating heme-iron from hemoglobin (Hgb) hydrolysate by dialysis was developed. Recovery of heme-iron increased with increasing Hgb concentration, whereas rejection of peptide and separation effciency expressed by HP ratio (heme-iron/peptide) did not show significant differences. HP ratio increased with increases in the degree of hydrolysis of Hgb and $KH_2PO_4$ concentrations of dialysis solution. Recovery of heme-iron decreased with increase in the pH of dialysis solution due to wash-out of heme-iron across the dialysis membrane caused by increase in solubility of heme-iron. Rejections of peptide were 74.5 and 87.5% (2 and 5 kDa of cut off size, respectively), whereas recovery of heme-iron decreased from 86.5 (2 kDa) to 63.1% (25 kDa). Amounts of heme-iron and peptide of dried heme-iron product were 21.7 and 77.0%, and HP ratio and production yield were 28.2 and 6.5%, respectively.