• Clean Technology
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• v.16 no.3
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• pp.162-171
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• 2010

The objective of this study is to develop cleaning agents for the indoor water supply pipe which is environmentally friendly and suitable for removing scale by using various organic acids, inorganic acids, and some additives. Among various organic acids, oxalic acid, citric acid, and malic acid showed good cleaning efficiency of iron oxides which were main components of the indoor water supply pipe scale. Several cleaning agents were formulated by adding chemical additives into these organic acids and evaluated for removal of iron oxides. In this study, it was found that nonionic surfactants were excellent for the removal of iron oxide scale among various additives. Two types of cleaning agents($F_1$, $F_2$) with comparatively high solvent power for iron oxides were formulated in this study. The cleaning agents $F_1$ made by organic acids and some additives were formulated to be safe and environmentally friendly, but seemed to have disadvantage due to their comparatively low cleaning efficiency of iron oxide than $F_2$. But, the cleaning agents $F_2$ prepared by adding inorganic acid a little to $F_1$ showed comparatively good cleaning efficiency of iron oxide and could be recommended for removing hard scale of iron oxides in the indoor water supply pipe. Thus, it is considered that the formulated cleaning agents should be selected based on the extent of scale in the indoor water supply pipe.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.219-223
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• 2001

Effects of hemoglobin (Hgb) concentration and degree of hydrolysis (DH) of Hgb on the separation of heme-iron were examined to produce highly enriched heme-iron from Hgb hydrolysate. Separation efficiency of Hgb hydrolysate with different DH was studied at wide pH range (pH $1.0{\sim}11.0$). Separation efficiency expressed as heme-iron/peptide ratio increased with decreasing Hgb concentration. When 5% Hgb (pH 10.0) was hydrolyzed using commercially available Esperase for 5 h at $50^{\circ}C$, DH was 25%. The precipitation of heme-iron-enriched peptides were remarkably high at pH range $3{\sim}6$. Optimal pH range for heme-iron with high heme-iron/peptide ratio shifted to acidic pH with increasing DHs of Hgb. The enriched heme-iron fraction in the precipitates showed a single band through urea-SDS-PAGE, with a molecular mass of 1 kDa. In the dry heme-iron product produced in a pilot bioreactor, content of heme-iron and heme-iron/peptide ratio were 27.1 and 38.7%, respectively, and production yield was 9.3%.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.1-1
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• 2011

We developed a new generalized synthetic procedure, called as "heat-up process," to produce uniform-sized nanocrystals of many transition metals and oxides without a size selection process. We were able to synthesize uniform magnetite nanocrystals as much as 1 kilogram-scale from the thermolysis of Fe-oleate complex. Clever combination of different nanoscale materials will lead to the development of multifunctional nano-biomedical platforms for simultaneous targeted delivery, fast diagnosis, and efficient therapy. In this presentation, I would like to present some of our group's recent results on the designed fabrication of multifunctional nanostructured materials based on uniform-sized magnetite nanoparticles and their medical applications. Uniform ultrasmall iron oxide nanoparticles of <3 nm were synthesized by thermal decomposition of iron-oleate complex in the presence of oleyl alcohol. These ultrasmall iron oxide nanoparticles exhibited good T1 contrast effect. In in vivo T1 weighted blood pool magnetic resonance imaging (MRI), iron oxide nanoparticles showed longer circulation time than commercial gadolinium complex, enabling high resolution imaging. We used 80 nm-sized ferrimagnetic iron oxide nanocrystals for T2 MRI contrast agent for tracking transplanted pancreatic islet cells and single-cell MR imaging. We reported on the fabrication of monodisperse magnetite nanoparticles immobilized with uniform pore-sized mesoporous silica spheres for simultaneous MRI, fluorescence imaging, and drug delivery. We synthesized hollow magnetite nanocapsules and used them for both the MRI contrast agent and magnetic guided drug delivery vehicle.

• Journal of Oriental Neuropsychiatry
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• v.7 no.1
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• pp.15-37
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• 1996

This thesis investigates 220 female students ranging from 19 to 26 years old attending universities in the Wonju area to determine the correlations between mental health and the density of serum iron . According to their serum iron levels, they were divided into three groups and analyzed with the GARS Scale Assessment and the THI Test Assessment. The results are as follows;1. On the comprehensive GARS Scale tests, for all groups, task, occupation and levels of university-related frustration(1) marked the highest scores.2. On the comparative assessment of each group's GARS Scale scores, Group A showed higher stress perception in terms of personal relationship(2,3) than any orther groups. 3. On the comprehensive THI test scores coverring all groups, Multiple subjective symptoms(I) marked the highest scores. 4. On the comparative assessment of each group's THI test scores, Group A showed higher Multiple subjective symptoms(I) and Irregularities of life(G) than any orther groups.5. Comparing and analyzing the GARS Scale Assessment and the THI Test, we found that Group A showed high stress perception, which may cause psychosomatic diseases such as 'yu zheng(鬱證;melancholia). With those results, we can see that the contant of serum iron is correlated to stress perception and the condition of mental health. In the future studies using the GARS Scale and the THI Test, it will be necessary to examine more subject groups in terms of multi-aspects and to investigate the standard group in more detail.

• Journal of environmental and Sanitary engineering
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• v.17 no.1
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• pp.57-62
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• 2002

Carbon cast iron and Zinc coated steel were the most widely used portable water of supply and distribution Pipeline system. The leaching of red water in portable water could produce sericus environmental sanitary problems. Due to the red water was the most alternative to inner scale of metal pipeline. So this study was conducted the impact of red water on scale products, and was evaluated by the corrosive metal contaminants of 20 fears over. Surface tests, metal surface composition measurements of samples XRF, XRD, and SEM(EDS), analysis were used to investigate the corrosion characteristies of carbon cast iron and Zinc coated steel. As the contaminants of Fe increased the red water of carbon castiron pipe increased due to the scale products amount of $Fe_2O_3$ (Hemite).

• Journal of the Korean institute of surface engineering
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• v.50 no.2
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• pp.85-90
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• 2017

The carbon steel formed the thick, somewhat porous, loosely adherent iron oxide scale when oxidized at $500-800^{\circ}C$ for 15 h in air. It formed the thicker, more porous, nonadherent scale consisting of FeS plus iron oxides in $Ar/1%SO_2$-mixed gas. It formed the much thicker, more porous, nonadherent scale consisting of FeS plus iron oxides in Ar/0.1% $H_2S$-mixed gas. However, the aluminized carbon steel formed the thin, protective $Al_2O_3$ surface scale even in $Ar/1%SO_2$-, and $Ar/0.1%H_2S$-mixed gas. Aluminizing drastically improved the corrosion resistance in (O, S, H)-containing gas.

• Journal of Korea Foundry Society
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• v.1 no.2
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• pp.2-9
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• 1981

Graphite spheroidization and scaling resistance of cast iron containing 5-10% Al were investigated. It is impossible to obtain spheroidal graphite in cast iron containing Al with 8 % and over, but possible to obtain spheroidal graphite even in cast iron with an Al content of about 10 % by increasing Si content. In the scaling test carried out under the heating condition of $950^{\circ}C$ in air for total of 50 hours, the scaling resistance of cast iron containing Al with 8 % and over was remarkably superior, and also spheroidal graphite cast iron was superior to flake graphite cast iron. The scale became thinner more compacts and more protective with increasing Al content.

• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.323-329
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• 2017

Purpose: Biocompatible capsules have recently been highlighted as a novel platform for delivering various components, such as drug, food, and agriculture pesticides, to overcome the current limitations of living systems, such as those in agriculture, biology, the environment, and foods. However, few active targeting systems using biocompatible capsules and physical forces simultaneously have been developed in the agricultural engineering field. Methods: Here, we developed an active targeting delivery platform that uses biocompatible alginate capsules and controls movements by magnetic forces for agricultural and biological engineering applications. We designed and fabricated large-scale biocompatible capsules, using custom-made nozzles ejecting alginate solutions for encapsulation. Results: To develop the active target delivery platforms, we incorporated iron oxide nanoparticles in the large-scale alginate capsules. The sizes of alginate capsules were controlled by regulating the working conditions, such as concentrations of alginate solutions and iron oxide nanoparticles. Conclusions: We confirmed that the iron oxide particle-incorporated large-scale alginate capsules moved actively in response to magnetic fields, which will be a good strategy for active targeted delivery platforms for agriculture and biological engineering applications, such as for the controlled delivery of agriculture pesticides and biocontrol agents.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.3
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• pp.12-17
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• 2020

The mechanical properties of the propellant with yellow iron oxide were slightly increased compared to the propellant with red iron oxide. The propellant with yellow iron oxide used two types of AP. As the ratio of small particles of AP increased, the burning rate increased. The propellant may be applied to the propellant under operating conditions of 17.5 mm/sec or less having a pressure index of 0.5. The burning rate downs in the mixer scale-up. The stress at maximum load of propellant decreased and the strain at maximum load increased in the mixer scale-up. The yellow iron oxide did not affect the adhesive force between the insulation/liner/propellant.

• Environmental Engineering Research
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• v.10 no.4
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• pp.165-173
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• 2005

Nano-sized iron particles were synthesized by reduction of $Fe^{3+}$ in aqueous solution under two reaction conditions, aerobic and anaerobic, and the reactivity of iron was tested by reaction with trichloroethene (TCE) using a batch system. Results showed that iron produced under anoxic condition for both synthesis and drying steps gave rise to iron with higher reduction reactivity, indicating the presence of oxygen is not favorable for production of nano-sized iron deemed to accomplish reactivity enhancement from particle sized reduction. Nano-sized iron sample obtained from the anoxic synthesis condition was further characterized using various instrumental measurements to identity particle morphology, composition, surface area, and particle size distribution. The scanning electron microscopic (SEM) image showed that synthesized particles were uniform, spherical particles (< 100 nm), and aggregated into various chain structures. The effects of other synthesis conditions such as solution pH, initial $Fe^{3+}$ concentration, and reductant injection rate on the reactivity of nano-sized iron, along with standardization of the synthesis protocol, are presented in the companion paper.