• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.141-151
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• 2007

This study was focused on iron removal from illite by L-ascorbic and oxalic acids. Iron has been shown as a secondary mineral such as iron oxides and hydroxides in illite ores. It is also known as a primary agent to degrade brightness index of the ores. Methods such as physical separation and chemical leaching with strong inorganic acids have been widely used to remove the iron from the ores. However, these methods are expensive and give rise to environmental problems. In this study, we examined an alternative method using solutions with different set of combination of sulfuric, hydrochloric, L-ascorbic, and oxalic acids. Compared to chemical treatments with only inorganic acids, our results demonstrate that an addition of L-ascorbic acid in inorganic acids results in decreasing both total concentrations of the inorganic acids and time for the treatments. The treatment with 0.15 M L-ascorbic acid and 0.25 M sulfuric acid in solution for 60 min significantly improved the brightness index from 42.4% to 74.4%. This improvement is similar to that of treatment with only 2.5 M sulfuric acid alone for 150 min. Mineralogical and chemical analyses were performed to compare the effect of acid leaching on illite powders. No obvious differences are observed in the mineralogical characteristics and particle size distributions of the samples. These results suggest that the treatment with the addition of L-ascorbic acid in sulfuric acid could effectively remove iron without modifying the physicochemical properties of illite under conditions used in this study.

• Korean Journal of Agricultural Science
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• v.51 no.1
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• pp.53-61
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• 2024

A total of 180 21-day-old weaning pigs ([Yorkshire × Landrace] × Duroc) with an initial body weight of 6.44 ± 0.01 kg were randomly assigned to 9 treatments for evaluating the effects of replacing dietary inorganic copper (Cu) and zinc (Zn) with glycine (Gly) or methionine (Met)-chelated Cu and Zn on growth performance and nutrient digestibility. The experimental period was 35 days. There were four replicated pens per treatment, with five pigs (three males and two females) per pen. Dietary treatments consisted of a basal diet (CON), in which the sources of Cu and Zn were in inorganic form. The inorganic Cu and Zn in the basal diet were replaced by glycine-chelated (GC) and methionine-chelated (MC) Cu and Zn by 30, 50, 70, or 100% to form the GC1, GC2, GC3, GC4, or MC1, MC2, MC3, MC4 groups. The 100% replacement of dietary inorganic Cu and Zn with GC or MC increased (p < 0.05) average daily gain, average daily feed intake, and gain-to-feed ratio. The complete replacement of dietary inorganic Cu and Zn with GC or MC led to enhanced (p < 0.05) digestibility of dry matter, nitrogen, Cu and Zn. Thus, the replacement of inorganic Cu and Zn with GC or MC can improve the growth efficiency and nutrient utilization of weaning pigs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.675-681
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• 1998

Low density polyethlene(LDPE0 films of 50${\mu}{\textrm}{m}$ thickness were fabricated with addition of antimicrobial agents of Rheum palmatum extract, Coptis chinensis extract, sorbic acid and Ag-substitude inorganic zirconium matrix in 1% concentration. The films were compared in physical properties, tested in antimicrobial activity against some selected microorganisms on the agar plate medium and then applied for packaging fresh curled lettuce and cucumber to preserve their qualities. The films with Rheum palmatum extract, Coptis chinensis extract, and Ag-substituted inorganic zirconium matrix did not show any antimicrobial activity on the disk test against Escherichia coli, Staphylococcus aureus, Leuconostoc mesenteroides, Saccharomyces cerevisiae, Aspergillus niger, Aspergillus oryzae, Penicilluium chrysogenum, while film with sorbic acid did against E. coli, S. aureus and L. mesenteroides. The added antimicrobial agents changed the color and light transmittance of the films, but did not affect their mechanical tensile strength, heat shrinkage and wettability. For the packaged curled lettuce and cucumber stored at 5$^{\circ}C$ and 1$0^{\circ}C$, all the LDPE films impregnated with antimicrobial agents showed the reduced growth of total aerobic bacteria in the vegetables compared with control film without any additive until it reached the level around 108/g. They did not give any negative effect on other quality attributes during storage.

• Archives of Pharmacal Research
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• v.18 no.4
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• pp.231-236
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• 1995

Effects of sodium salts of various monovalent inorganic anions on transdermal permeation of salicylic acid were investigated. In in-vitro experiment using a Franz-type diffusion cell and excisicylic acid were investigated. In-vitro experiment using a Franze-type diffusion cell and excised mouse skin, the permeation-enhancing activities of the sodium salts of inoraganic anions were rougly proportional to lyotropic Hofmeister serlling abilities of the anions l F/sup -/

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.78-83
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• 2001

In this work, the surface of inorganic fillers were modified with some functional groups such as stearic acid, aliphatic long chain, vinylsilane and aminosilane to control the interaction between inorganic fillers and polymer matrix. Ethylene-vinyl acetate copolymers (EVA) with various amount of vinyl-acetate content and copolyether-ester elastomer were used as polymer matrix. The addition of inorganic fillers increases flame retardancy, but results in steep drop of electrical and mechanical properties, which may be caused by the defect in the interface between organic/inorganic hybrid composites. The hybrid composites are found to show better mechanical properties and higher volume resistivities as inorganic fillers are well dispersed and have good adhesion with polymer matrix. Also, the most effective type of functional group coated on fillers depends on the chemical structure of polymer.

• 한국전기화학회:학술대회논문집
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• 2003.07a
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• pp.169-171
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• 2003

Organic/inorganic hybrid membranes have been prepared and evaluated as polymer electrolytes in a polymer electrolyte membrane fuel cell (PEMFC). Previously, partially fluorinated poly (arylenether) was synthesized and the polymer was sulfonated by fuming sulfuric acid$(30\%\;SO_3)$. Modification of these polymers with coupling agent and inorganic materials was carried out to prepare membranes. Membranes cast from these materials were investigated in relation to the proton conductivity and weight loss at the room temperature. It was found that these membranes had a higher conductivity of $10^{-2}\;Scm^{-1}$ at the room temperature. But inorganic materials have leaked out from the hybrid membrane. If this problem is resolved, organic/inorganic hybrid membranes will become satisfactory Polymer electrolytes for the PEMFC.

• The Journal of the Korean dental association
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• v.47 no.6
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• pp.364-372
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• 2009

치주 질환으로 인하여 소실된 치주조직을 재생시키려는 여러 술식이 많이 연구되고있다. 그 중 bioactive factor의 적용은 치주조직의 재생에 있어서 우수한 치료법으로 평가되고 있으며, 이를 수용부에 적절히 적용하기 위한 운반체로 생체친화적인 중합체가 이용되고 있다. 본 연구의 목적은 PLGA를 Inorganic filler에 혼합시킨 재료를 성견의 일벽성 골내낭에 적용하여 이 재료의 생체 친화성과 생체 흡수도를 보고자 하는 것이다. 5마리의 비글견에서 제 3 소구치를 모두 발치한 뒤, 8주간의 치유기간이 지나고 제 2 소구치 원심면과 제 4 소구치 근심면에 5mm 깊이, 4mm폭의 일벽성 골내낭을 형성하였다. 좌측 defect에는 PLGA/inorganic filler matrix를 이식하였고 우측에는 아무것도 이식하지 않은 대조군으로 나누어 술 후 8주에 희생하여 치유 결과를 조직학적으로 비교 관찰하였다. 조직학적 분석 결과, 모든 결손부에서 염증의 소견이 관찰되지 않았으며 치근흡수와 유착은 발견되지 않았다. 백악질과 치조골, 치주인대를 포함한 치주조직의 재생에 있어서 대조군, 실험군 간에 조직학적으로 치유양상에 있어 차이를 많이 보이지 않았으며 PLGA/inorganic filler matrix는 8주 내에 완전히 흡수되어 결합조직이나 신생골내에서 그 흔적을 발견할 수 없었다. 이러한 결과는 PLGA/inorganic filler matrix는 생체친화성 및 생체흡수성이 우수한 재료로서 치주 조직의 재생 치료에 있어서 신체활성인자의 scaffold로 사용될 수 있는 가능성을 보여주었다.

• Journal of the Korean Ceramic Society
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• v.24 no.4
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• pp.343-348
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• 1987

The effects of salts such as aluminum sulfate as inorganic salt(2-4%), and sodium salts of citrate, tartrate, succinate, potassium tartrate and gelatin as organic salts(0.1%) on the formation of ${\alpha}$-calcium sulfate hemihydrate from by-product gypsum of phosphoric acid process under hydrothermal condition at 123$^{\circ}C$ and 133$^{\circ}C$ were investigated. Aluminum sulfate solution exhibited the catalystic effected on the crystallization of ${\alpha}$-calcium sulfate hemihydrate of which was assumed in the prismatic form, and organic salts solution exhibited little effect on the catalystic action to the crystallization, than inorganic salts. In the acidic solution with sulfuric acid(pH=2), needle like crystal of calcium sulfate hemihydrate was obtained. Hydrothermal process with aluminum sulfate solution also showed certain amounts of impurity removal such as phosphorus penataoxide from calcium sulfate hemihydrate.

• The Korean Journal of Mycology
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• v.18 no.2
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• pp.109-114
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• 1990

The effect of different carbon and nitrogen compounds on the growth and sporula­tion of Curvularia clavata Alcorn (Herberium No. IMI264075) has been studied. All the carbon sources tried were well utilized by the pathogen though glucose, and sucrose supported the best growth while glucose, maltose and sucrose the sporulation of the fungus. Of the nine nitrogen compounds, L-glutamic acid supported the best growth while aspartic acid and L-glutamic acid the sporulation of the fungus. Growth and sporulation were generally better with organic than inorganic nitrogen sources. Ammonium sulphate was the best inorganic source. A sudden drop of pH value of the culture media after 4 days of incubation did not favour good growth of the fungus.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.3
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• pp.130-136
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• 1981

Rice hull was reduced to ash by carbonization grades to illcuidate alkalinity increase and extract of inorganic nutrients in the rice hull charcoal. Alkaline reaction of water extraction was neutral at less carbonized charcoal, but much carbonized ash from 65% weight loss reached over 10 of pH value, also origin shape of rice hull was maintained until near 65% carbonized grade. Therefore, physical properties sustained good condition for seedling bed. The more charcoal carbonized to ash, the pH value and concentration of inorganic nutrient in their extracts were increased gradually. Nitric acid concentrations for neutralizing extract from charcoal were stronger in proportion to the carbonized grade but 0.1 N nitric acid solution was very reasonable to neutralize the 65% carbonized charcoal for mixing with heavy texture acidy soil(pH 5.3) of uncultivated deep horizon to transplant the tobacco seedlings. Volume ratio mixing for seedling bed is adequate at five of ash to one of acid solution. Neutralization with nitric acid solution also accelerated extraction of the inorganic nutrient in rice hull ash. Tobacco seedlings grown on bed mixed with neutralized rice hull charcoal and soil had shown better results on the agronomic measurement than alkaline ash bed, and phosphorus and cations were uptaken more amounts.