• Tribology and Lubricants
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• 제35권2호
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• pp.132-138
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• 2019

In this study, we demonstrate the effects of the acidic properties of montmorillonite (MMT), which is commonly used as a catalyst, on the conversion and selectivity of the dimer acid methyl ester (DAME) synthesis. We synthesize DAME by the dimerization of conjugated linoleic acid methyl ester (CLAME) and oleic acid methyl ester using MMT KSF. Incidentally, trimer acid methyl ester was formed as a by-product during the DAME synthesis. There is a necessity to adequately adjust the strength and quantity of the acid site to control the selectivity of DAME. Therefore, we vary the pH of the MMT acid by using various metal hydroxides. The purpose of this study is to increase the yield of monocyclic dimer acid methyl ester, which is a substance with adequate physical properties for industrial applications (e.g., lubricant and adhesive, etc.), using a heterogeneous catalyst. We report the dimerization of fatty acid methyl ester by using base treated-KSF, and apply it to conjugated soybean oil methyl ester. Then, we transmute the acid site properties of KSF, such as pH of 5 wt.% slurry KSF and various alkali metals (Li, Na, K, Ca). Characterization of base treated-KSF using a pH meter, x-ray diffraction, inductively coupled plasma-atomic emission spectrometer, Brunauer-Emmett-Teller surface analysis, and temperature-programmed desorption. We conduct an analysis of CLAME and DAME using nuclear magnetic resonance spectroscopy, gas chromatography, and gel permeation chromatography. Through these experiments, we demonstrate the effects of the acidic properties of KSF on the conversion and selectivity of the DAME synthesis, and evaluate its industrial potential by application to waste vegetable oil.

• 공업화학
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• 제24권6호
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• pp.633-638
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• 2013

이 연구에서는 비스-디메틸아미노메틸 포스핀산, 비스-디에틸아미노메틸 포스핀산, 비스-디부틸아미노메틸 포스핀산을 붓으로 칠한 리기다 소나무의 연소성을 시험하였다. 15 w%의 비스-디알킬아미노알킬 포스폰핀 수용액으로 리기다 소나무에 3회 붓칠하여 실온에서 건조시킨 후, 콘칼로리미터(ISO 5660-1)를 이용하여 그의 연소성을 시험하였다. 그 결과, 비스-아미노알킬 포스핀산 유도체로 처리한 시험편은 처리하지 않은 시험편에 비하여 그의 연소 억제성을 부분적으로 향상시켰다. 특히 비스-디에틸아미노메틸 포스핀산으로 처리한 시험편은 미처리 시험편에 비해 각각 낮은 총 열방출률($60.9MJ/m^2$)과 낮은 유효연소열(15.20 MJ/kg)을 나타내었다. 따라서 비스-디알킬아미노알킬 포스핀산 유도체로 처리한 시험편은 순수 리기다 소나무 시험편에 비하여 부분적으로 낮은 연소성질을 나타내었다.

• 대한치과보철학회지
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• 제41권3호
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• pp.379-386
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• 2003

Statement of problem. Resin cements are widely used in adhesive dentistry specially on all ceramic restorations. It is needed to find out adequate bonding strength between different porcelain surface treatments, commercially available porcelains, and different resin cement systems. Purpose. The purpose of this study was to evaluate shear bond strength of resin cements bonded to porcelains in three different modalities; 5 different porcelain surface treatments, 3 different resin cement systems and 3 different commercially available pressable porcelains. Material and Method. This study consisted of 3 parts. Part I examined the effect of five different surface treatments on the pressable porcelain. Fifty discs (5 mm in diameter and 3 mm in height) of Authentic porcelain were randomly divided into 5 groups (n = 10). The specimens were sanded with 320 grit SiC paper followed by 600 grit SiC paper. The specimens were treated as follow: Group 1-Sandblasting (aluminum oxide) only, Group 2 - sandblasting/ silane, Group 3 - sandblasting/ acid etching/ silane, Group 4 - acid etching only, Group 5 - acid etching/ silane. Part II examined the shear bond strength of 3 different resin cement systems (Duolink, Variolink II, Rely X ARC) on acid etching/ silane treated Authentic pressable porcelain. Part 3 examined the shear bond strength of Duolink resin cement on 3 different pressable porcelains (Authentic, Empress I, Finesse). All cemented specimens were stored in distilled water for 2 hours and tested with Ultradent shear bond strength test jig under Universal Instron machine until fracture. An analysis of variance(ANOVA) test was used to evaluate differences in shear bond strength. Result. The shear bond strength test resulted in the following: (1) Acid etched porcelains recorded greater shear bond strength values to the sandblasted porcelains. (2) Silane treated porcelains recorded greater shear bond strength values to non-silane treated porcelains. (3) There was no significant difference between sandblasting/ acid etching/ silane treated and acid etching/ silane treated porcelains. However those values were much higher than other three groups. (4) The shear bond strength with Variolink II was lower than the value of Duolink or Rely X ARC. (5) The shear bond strength of Finesse was lower than the value of Authentic or Empress I.

• 한국의류학회지
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• 제20권6호
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• pp.992-1001
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• 1996

The binding of polyethylene glycol (PEG, average molecular weight 600) to cotton fabrics was achieved by using pad-dry-cure process in the presence of citric acid, MgCl3·6H3O, DMDHEU, and TEAHCL. Treated fabrics were dyed with direct, acid, and basic dye. Wrinkle recovery angles, durable press rate, wettability, dyeability and color fastness to washing of all treated cottons were evaluated. The results of this study were as follows: 1. The wrinkle resistance of the PEG treated cottons was increased by increasing PEG and DMDHEU concentration. 2. The wettability of the PEG treated cottons was decreased by increasing PEG and DMDHEU concentration, increased by increasing TEAHCL concentration. 3. PEG/DMDHEU/TEAHCL treated cottons had greater affinity on direct, acid, and basic dye than untreated cottons, and dyeability of the modified cottons was improved compare to untreated fabrics. 4. Color fastness to washing of the PEG/DMDHEU/TEAHCL treated cottons was good except for the wash fastness of the direct dye.

• 한국환경과학회지
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• 제1권2호
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• pp.81.1-86
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• 1992

The amounts of ascorbic acid in chloroplasts treated with light and light+paraquat (PQ) were reduced by 81 and 82% of initial level, respectively at 24 hr at incubation. And those treated with dark and dark+PQ were decreased by W and 55% of the original level, respectively. Malondialdehyde (MDA) contents at 24 hr of dark and dark+PQ treatment were increased by 6 and 31% of the initial level, respectively. When chloroplasts were treated with light and light+PQ, MDA contents after 24 hr were increased by 88 and 146% of the initial level, respectively. SOD activities treated with light and light+PQ were increased by 10 and 20% of the initial level, respectively for 3 hr and thereafter reduced by 46 and 49% of the original level, respectively at 24 hr. However, the SOD activities treated with dark and dark+PQ were decreased by 37 and 30% of the initial level, respectively. It is considered that PQ triggers the oxidation of ascorbic acid, the induction of lipid peroxidation and the inactivation of SOD under light so that PQ has inhibitors effect on the pathway of plant metabolism. Key word: ascorbic acid, malondialdehyde, superoxide dismutase, paraquat, lipid peroxidation.

• 한국세라믹학회지
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• 제33권7호
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• pp.823-831
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• 1996

Due to the intrinsic low surface activation of ${\gamma}$-alumina it has been used limitely in practice. Accordingly forward enhancing its utility ${\gamma}$-alumina surface was treated with slfuricf aicd nitric acid and chloric acid respec-tively. Subsequently the effects of surface activity on the surface electrical characteristics were investigated. The ${\gamma}$-alumina was prepared by the precipitation of aluminium nitrate [Al(NO3)3.9H2O] using ammonia water as a precipitator and it was chemically treated with such acids mentioned above. The surface and morphology of the acid-treated ${\gamma}$-alumina were analysed by XRD, BET and the surface activities were measured by the amine titration methods. The interfacial properties of the ${\gamma}$-alumina dispersed in electrolyte solution were esti-mated by the surface charge density measured using potentiometric tiration. Based on the relation between surface charge density and the acid amount the following results were drawn for the surface and interfacial electrical properties ; Acidic properties of surface-treated alumina increase with anion load on alumina surface. P. Z. C decreases with acid amount on alumina surface. The surface charge densities were apart from electrolyte ionic strength. The acidity of ${\gamma}$-alumina is linearly dependent on the P. Z,.C when the ${\gamma}$-alumina was dispersed in aqueous electrolyte solution.

• 한국환경보건학회지
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• 제20권2호
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• pp.80-89
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• 1994

The effects of amphotericin B (150 $\mu$g/ml) and cycloheximide (10 $\mu$g/ml) on the biosynthesis of phospholipid and their fatty acid composition in chloroplast isolated from Chlorella were analyzed to compare with control. The levels of total lipid, phosphatidylethanolamine (PE), and phosphatidylcholine (PC) in the group treated with antibiotics were decreased. However, the biosynthesis of phosphatidylinositol (PI) was not affected by antibiotics. The major fatty acid in chloroplast envelope was linolenic acid (27.71%) in control and stearic acid (21.59%) in the group treated with amphotericin B. It was showed that the group treated with cycloheximide contained more unsaturated fatty acid than the control.

• 동의생리병리학회지
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• 제22권6호
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• pp.1495-1499
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• 2008

The purpose of this study is to investigate the effect of water extract from Artemisiae Argi Folium (WAAF) on hydrogen peroxide production within mouse macrophage Raw 264.7 Cells treated with gallic acid, EtOH, LPS, and acetaminophen. WAAF (0${\sim}$400 ug/mL) was treated with gallic acid, EtOH, LPS, acetaminophen. And the intracellular productions of hydrogen peroxide were measured by dihydrorhodamine 123 (DHR) assay. WAAF showed the restoration of the intracellular productions of hydrogen peroxide which were reduced by gallic acid, EtOH, LPS, and acetaminophen in Raw 264.7 Cells. WAAF could be supposed to have the immunological activity related with macrophage's oxidative burst.

• 한국의류학회지
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• 제27권11호
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• pp.1252-1259
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• 2003

The purpose of this study is to develop multi-functional fabrics by chitosan added on acrylic acid grafted cotton kintted fabrics. Therefore physical properties such as antimicrobial activity, deodorization rate, moisture regain, whiteness, and tensile strength of chitosan added on acrylic acid grafted cotton kintted fabrics were investigated. The results are as follows; According to increased chitosan's concentration, grafting yield was decreased. Therefore thickness of film by treated chitosan added on acrylic acid grafted cotton kintted fabric became thin. FT-IR spectra of chitosan add on acrylic acid grafted cotton kintted fabric clearly showed peaks of COOH and NH$_2$. Antimicrobial activity and deodorization rate of chitosan add on acrylic acid grafted cotton kintted fabrics were increased greatly than untreated. And their durability of laundry were good, Moisture regain of treated fabrics was higher than untreated. Whiteness and tensile strength of treated fabrics were lower than untreated.

• 동아시아식생활학회지
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• 제23권1호
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• pp.92-97
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• 2013

This study was conducted to understand the quality characteristics of salt fermented anchovies with heat treatment by measuring their chemical compositions. The heat-treated and non-heat treated salt fermented anchovies contained, respectively, 63.21 and 66.51% of moisture, 2.24 and 2.12% of total nitrogen (TN), and 1,537 and 1,520 mg/100 g of amino nitrogen (AN). In addition, heat-treated and non-heat-treated salt fermented anchovies contained 127 and 134 mg/100 g of volatile basic nitrogen (VBN), respectively. Moreover, measured the microbial level of heat-treated and non-heat-treated salt fermented anchovies was $2.58{\times}10^4$ and $3.61{\times}10^2$ CFU/mL, respectively. Also, the heat-treated and non-heat-treated salt fermented anchovies 3.65 and 0.30 units of protease activities, respectively. The total free amino acid contents in heat-treated and non-heat-treated salt fermented anchovies was 4,964 and 6,638 mg/100 g, respectively. The major free amino acid were glutamic acid, leucine, lysine, alanine, valine, isoleucine. Our results provide the characteristics of salt fermented anchovies and encourage their application for the food industry and cooking.