• 환경위생공학
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• 제14권4호
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• pp.143-149
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• 1999

In the tungsten industry as light source material, tungsten filament which used as light source material could form after molybdenumwire which used as the center supporter for coil shape tungsten wire was removed. This process uses hydrogen peroxide, Ozone and UV(Ultraviolet)Lamp, for the quantity of hydrogen peroxide decrease. The results were as follows : 1. An incandescent electric Lamp type : FL(FL-20) type : A standard of commodity (P.W.: $19{\pm}1.0mg$, $C.R:4.5{\pm}0.3{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time : 65Min., P.W.: 18.60mg, $C.R.:4.60{\Omega}$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide; Reaction Time : 64Min., P.W.: 18.61mg, C.R.: $4.61{\Omega}$ 2. A Fluorescent Lamp Type : GLS(GLS-40) Type : A standard of commodity(P.W.: $11.8{\pm}0.2mg$$65{\pm}1.5{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time: 72Min, P.W.:11.88mg, C.R.: $65.62\Omega$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide;Reaction Time:71Min., P.W.:11.88mg, C.R.: $65.63\Omega$

• 한국산업보건학회지
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• 제28권1호
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• pp.51-60
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• 2018

Objectives: Currently, there is only limited knowledge regarding the hazard of low-level exposure to CMR materials in workplaces. To overcome this limitation, a reference concentration for workers($RfC_w$) from among the risk assessment tools proposed by the US EPA is widely used to set a provisional workplace exposure level(PWEL) for CMR materials for which there are no established Korea Occupational Exposure Limits(KOELs) or subjective chemicals for work environment measurements as regulated by Korea Ministry of Employment and Labor(KMOEL). A simple European calculator of derived no effect level(SECO-DNEL) as proposed by REACH can also be used in place of $RfC_w$ to set the PWEL for chemicals. This study was performed to test the acceptability of using SECO-DNEL as an alternative to $RfC_w$ when setting a PWEL for low-level exposures. Methods: The $RfC_w$ and DNEL for the five CMR materials of dinitrogen oxide, catechol, 2-phenoxy ethanol, carbitol, and carbon black were calculated using the dose-response assessments of the US EPA for $RfC_w$ and REACH guidance for SECO-DNEL, respectively. They were compared using paired t-tests to determine the statistical differences between them. Results: For the five chemicals, the $RfC_w$ were 2.53 ppm, 0.10 ppm, 1.73 ppm, 1.66 ppm, and $0.05mg/m^3$, respectively, while the SECO-DNEL were 2.01 ppm, 0.11 ppm, 1.83 ppm, 1.77 ppm, $0.14mg/m^3$, respectively. There was no statistically significant difference between $RfC_w$ and SECO-DNEL. Conclusions: This study suggests that the SECO-DNEL could be applied in place of $RfC_w$ to set a PWEL for low-level exposure to chemicals, especially CMR materials. To further ensure the reliability of SECO-DNEL as an alternative tool, more chemicals should be applied for calculation and comparison with $RfC_w$.

• 산업식품공학
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• 제14권1호
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• pp.1-6
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• 2010

본 연구에서는 오가피(Acanthopanax sessiliflorus)의 열매 발효주를 제조하였고 발효 중 생리활성 성분의 함량 변화를 측정함으로써 그 특징을 규명하였다. 열매의 일반성분 조성은 수분75.74${\pm}$0.49%(w/w), 조단백질 12.51${\pm}$1.23%(w/w), 조지방 4.20${\pm}$0.51.%(w/w), 조회분 5.21${\pm}$1.64%(w/w)이었으며 주된 미네랄 성분은 칼륨(12.94${\pm}$0.08 mg/g), 칼슘 (1.53${\pm}$0.06 mg/g), 마그네슘(1.12${\pm}$0.05 mg/g) 등 이었다. 발효주 제조를 위해 설탕으로 24, 26, 28, 30, 32$^{\circ}$Brix가 되도록 가당하고 발효 한 결과 30$^{\circ}$Brix 이상 가당 하였을 경우 알콜 발효가 저해되었으므로 목적하는 최종 알콜 농도와 잔당에 따라 24-30$^{\circ}$Brix가 되도록 조절하는 것이 바람직하였다. 발효가 진행되면서 총 폴리페놀의 함량은 증가하는 경향을 보였고 20${^{\circ}C}$로 발효한 경우가 125.24${\pm}$1.86 mg/mL로 25${^{\circ}C}$(99.69${\pm}$2.11 mg/mL), 30${^{\circ}C}$(95.55${\pm}$1.54 mg/mL)에서 발효한 경우보다 더 많은 총 폴리페놀 함량을 보였다. 또한 전자공여능을 측정 한 결과 20, 25, 30${^{\circ}C}$에서 발효시 각각 85.9${\pm}$2.3, 55.7${\pm}$2.5, 55.2${\pm}$3.4%로 20${^{\circ}C}$에서 발효하였을 경우 가장 높은 전자공여능을 보였는데 이는 1%(w/v) $\alpha$-tocopherol의 전자공여능과 비슷한 수준이었다. 오가피 열매의 주된 생리활성 물질인 eleutheroside B 함량은 발효가 진행됨에 따라 증가하여 최대 146.58${\pm}$4.10 $\mu$g/mL에 이르렀다. 그러나 발효 온도에 따라 eleutheroside B 함량은 차이가 없음을 알 수 있었다. 본 연구를 통해 착색료나 동물사료로 사용되거나 폐기되는 오가피 열매가 생리활성물질을 다량 함유한 고부가가치 기능성 식품 소재로 활용될 수 있는 가능성을 제시하였다.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.314-320
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• 1999

Several bisphosphine- and bisphosphite-substituted Re-imido complexes have been prepared from Re(NPh)(PPh3)2Cl3, 1, and Re(N-C6H3-i-Pr2)2Cl3(py), 4. Compound 1 reacted with trimethyl phosphate (P(OMe)3) to give a mixture of two isomers,mer,trans-Re(NPh)(P(OMe)3)2Cl3, 2, and fac,cis-Re(NPh)(P(OMe)3)2Cl3, 2a. In this reaction, the mer,trans-isomer is a major product. Complex 1 also reacted with triethylphosphine (PEt3) to exclusively give mertrans-Re(NPh)(PEt3)2Cl3, 3. Compound 4 reacted with trimethylphosphine (PMe3) to give mer,trans-Re(N-C6H3-i-Pr2)(PMe3)2Cl3, 5, which was converted to mer-Re(N-C6H3-i-Pr2)(PMe)(OPMe3)Cl3, 6, on exposure to air. Crystallographic data for 2: monoclinic space group P21/n, a = 8.870(2) Å, b = 14.393(3) Å, c = 17.114(4) Å, β = 101.43(2)°, Z = 4, R(wR2) = 0.0521(0.1293). Crystallographic data for 5: orthorhombic space group P212121, a = 11.307(l) Å, b = 11.802(l) Å, c = 19.193(2) Å, Z = 4, R(wR2) = 0.0250(0.0593). Crystallographic data for 6: orthorhombic space group P212121, a = 14.036(4) Å, b = 16.486(5) Å, c = 11.397(3) Å, Z = 4, R(wR2) = 0.0261(0.0630).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1079-1082
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• 2004

CuPc와 ZnPc를 이용하여 이종 접합 구조에서의 광기전 특성을 연구하였다. $CuPc/C_{60}$, $XnPc/C_{60}$의 이종 접합 구조에서 $C_{60}$의 접합 두께 비율을 1:1 (20nm:20nm), 1:2 (20nm:40nm), 1:3 (20nm:60nm)로 가변하여 두께와 물질에 따른 광기전 특성 및 엑시톤 억제층의 효과를 분석하였다. 광원은 500W Xe lamp를 이용하였으며, 광원의 세기는 보정된 radiometer/photometer와 Si-photodiode로 dark, 10, 25, 60, 80 그리고 100mW/$cm^2$로 주사하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.837-838
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• 2013

• 생명과학회지
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• 제13권4호
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• pp.498-504
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• 2003

맛버섯( Pholiota nameko KACC50453)의 균사체 배양 특성에 관한 연구 결과 맛버섯 균사체의 배양에 적합한 기본 배지는 ME였으며, 최적 배양 온도는 $25^{\circ}C$, 최적 초기 pH는 5.5였다. 맛버섯 균사체 생장을 위한 최적 배지 조성은 glucose 3%(w/v),malt extrac 0.25%(w/v), yeast extract 0.25%(w/v),$KH_2PO_4$ 0.046%(w/v),$K_2HPO_4$ 0.1%(w/v),$MgSO_4$ $.$$7H_2O$0.05% (w/v)로 나타났다.기본배지(ME)와 최적배지로 액체 배양한 결과 최적 배지에서 균사생장이 양호하였다.

• 대한화장품학회지
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• 제22권2호
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• pp.132-140
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• 1996

The effect of a novel delivery system, water in oil emulsion containing chitosan hydrogel as a inner phase (W/O-C) was evaluated, and the relationships between the skin permeation, the skin primary irritation and the skin turnover rate of AHAs were discussed. We selected glycolic acid (GA), lactic acid (LA), malic acid (MA), and tartaric acid (TA) as model AHAs. The steady state fluxes of 4 AHAs across the excised hairless mouse skin increased as the molecular weights of the AHAs decreased. (GA>LA>MA>TA). The skin turnover times were shortened in all AHAs, compared with control. The skin permeation and the skin primary irritation of the LA decreased and the skin turnover time increased, as the pH increased. The maximum therapeutic index was obtained with pH 3.8, 0.5 M LA. It was suggested that the skin permeability of LA might be a main factor for prediction of the skin irritation and the skin turnover time. On the other hand, the W/O-C containing pH 3.8, 0.5 M LA indicated a good sustained release property of LA, compared with water in oil emulsion without chitosan hydrogel (W/O) or oil in water emulsion (O/W). The skin permeability and the skin irritation of AHAs from the W/O-C edcreased, compared with W/O or O/W, however the skin turnover time showed almost the same value as W/O or O/W. In conclusion, we suggest that the control of the skin permeation of AHAs would be an important tool for reducing the skin irritation and for maintaining the positive effect of AHAs, and the W/O-C system could be a potential candidate for future cosmetological application of AHAs.

• 한국재료학회지
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• 제12권5호
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• pp.407-413
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• 2002

Eutectic high chromium cast irons containing 17%Cr and 26%Cr were produced for this research by making each of them solidify unidirectionally. Abrasion wear test against SiC or $Al_2$O$_3$bonded paper was carried out using test pieces cut cross-sectionally at several distances from the chill face of castings. The wear resistance was evaluated in connection with the parameters such as eutectic colony size($E_w$), area fraction of boundary region of the colony($S_B$) where comparatively large massive chromium carbides are crystallized and, average diameter of chromium carbides in the boundary region($D_c$). The wear rate($R_w$), which is a gradient of straight line of wear loss versus testing time, was influenced by the type and the particle size of the abrasives. The $R_w$ value against SiC was found to be larger than that against A1$_2$O$_3$under the similar abrasive particle size. In the case of SiC, the $R_w$ value increased with an increase in the particle size. The $R_w$ value also increased as the eutectic colony size decreased, and that of the 17%Cr iron was larger than that of the 26%Cr iron at the same $E_w$ value. Both of the $S_B$ and $D_c$ values were closely related to the $R_w$ value regardless of chromium content of the specimens. The $R_w$ values of the annealed specimens were greater than those of the as-cast specimens because of softened matrix structures. As for the relationship between wear rate and macro-hardness of the specimens, the hardness resulting in the minimum wear rate was found to be at 550 HV30.

• 한국주조공학회지
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• 제19권1호
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• pp.33-37
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• 1999

White cast iron of 3%C-10%Cr-5%Mo-5%W was casted, and then heat treated with three different methods such as homogenizing, austenitizing and tempering to observe its effects on the microstructure, hardness and abrasive wear resistance. In uni-directional soldification, bamboo tree-like $M_7C_3$ carbide grew along with the heat flow direction, and fishbone-like $M_6C$ carbide was dispersed randomly among $M_7C_3$ carbides. While almost pearlitic structures were observed in the as-cast specimen, those of the heat treated specimens consisted of secondary carbide, retained austenite and tempered martensite. In austenitized specimen, the amounts of retained austenite were 60.88% due to the higher cooling rate encountered in forced air cooling. On the other hand, the amounts of retained austenite were reduced from 60.88% to 23.85% in tempered specimen due to the transformation of austenite into tempered martensite. The hardness of tempered specimen showed the highest value, and then decreased in the order of austenitized, as-cast and homogenized specimens. But, the abrasive wear resistance of austenitized specimen was the highest, and then decreased in the order of tempered, as-cast and homogenized specimens.