• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.327-328
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• 2006

본 연구에서는 0-3 타입의 압전 세라믹 - 고분자 복합소재를 제조하기 위해서 $Pb(Zr_{0.54}Ti_{0.48})O_3$ + 0.2 wt% $Cr_2O_3$ + 1 wt% $Nb_2O_5$ 조성을 기본 조성으로 하여, 세라믹-고분자 첨가량에 따른 복합소재의 전기적 특성과 여러 분극조건, 즉 분극온도, 분극시간, 분극전압 변화에 의한 압전 특성을 고찰하였다. 세라믹 첨가비율이 증가함에 따라 유전상수와 압전상수($d_{33}$)는 증가하였으며, 전압상수($g_{33}$)는 급격히 감소하는 경향을 보였으며, 분극시간과 분극전압도 전기적 특성에 영향을 주는 것을 확인하였다. 분극전압 5KV 인가한 고분자 15% 첨가한 복합 소재에서 유전상수 13, 압전상수 $d_{33}$ 23(${\ast}10^{-12}C/N$), 전압상수 $g_{33}$ 170($10^{-3}v.m/N$)의 우수한 특성을 나타내었다.

• 한국세라믹학회지
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• 제30권9호
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• pp.768-774
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• 1993

Sulphuric acid was intercalated in mesophase pitch based graphite fiber (Thornel P100 of Amoco), PAN based graphite fiber (M40 of Thoray) and PAN based carbon fiber (T300 ofThoray, TZ307 of Taekwang in Korea) by 0.4wt% CrO3/H2SO4 solution. The degree of crystallization of fibers increased P100, M40, TZ307, T300 fiber in order and their d002 values were 3.384, 3.424, 3.470, 3.493$\AA$, respectively. After intercalation P100 fiber formed 1 stage compound whose d002 value was 3.994$\AA$(d001=7.988$\AA$). Other fibers showed (002) reflection belonging to their 1 stage comound and prinstine fiber.

• Korean Chemical Engineering Research
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• 제43권2호
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• pp.318-323
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• 2005

초임계수 산화는 난분해성 유기화합물의 분해를 위한 공정으로 각광받고 있다. 본 연구에서는 연속반응기에서 온도 $387-500^{\circ}C$, 압력 250 bar의 초임계수 조건하에서(EDTA 분해효율) 체류시간 15.9-88.9초의 범위의 EDTA 분해효율을 측정하였다. 이때 산화제로는 과산화수소($H_2O_2$)를 사용하였다. EDTA의 분해효율은 온도 및 산화제투입량의 증가에 따라 상승하였으며, 반응물 도입유속의 감소 즉, 체류시간의 증가에 따라서 상승하였다. 본 연구결과 온도 $500^{\circ}C$, 압력 250 bar, 산화제 투입량 400%의 조건에서 최대 99.6%의 분해효율을 나타내었다. 분해효율에 미치는 온도의 영향이 산화제 투입량 증가의 영향보다 컸으며, 5,000 mg/L의 EDTA($COD_{Cr}$로서 3,063 mg/L)의 99% 이상 분해효율은 온도 $500^{\circ}C$와 압력 250 bar의 초임계수 산화조건에서 산화제투입량 200% 이상 및 체류시간 40.1초 이상에서 얻을 수 있었다.

• 한국의류학회지
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• 제25권3호
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• pp.598-605
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• 2001

The study that has been conducted is the consideration of the durability of dye, antibacterial activity, and deodorizing effects of cotton and silk textiles dyed with a botanical dying material that has been used in various ways over the years as Korean diet and folk remedies, the pomegranate. 1. The results of the K/S value of dying according to the types of mordants of textiles dyed with pomegranate extract the following have been discovered: The increase of K/S value of dying of the silk textiles appear to be higher than that of the cotton textiles. Next, silk textiles that have been treated with FeSO$_4$.7$H_2O$ appear to be at the highest. 2. The results of the color change measurement show a difference of color can be noticed according to the types of mordant. As opposed to those textiles that had been only scured textiles, all of the dyed textiles appeared to turn yellow. 3. Textiles that had been treated with $K_2$Cr$_2$O(sub)7 recorded the highest durability according to the colorfastness to light results. In the case of the cotton textiles colorfastness to washing, all appeared to show exceptional results of 3rd class or higher, excluding the textiles that had been treated FeSO$_4$.7$H_2O$. However silk textiles recorded relatively low classes of below 3rd to 4th class. For the colorfastness to washing of pollution, the results for both the cotton and silk textiles were excellent at class 4-5. The results of colorfastness to perspiration, colorfastness to rubbing, and colorfastness to dry cleaning showed comparatively exceptional results of 3rd to 4th class or higher when it came to dyed textiles. 4. According to the measurements of antibiosis, dyed textiles that had been treated with SnCl$_2$.2$H_2O$ appeared to show an exceptional bacterium decrease of approximately 70%. 5. According to the deodorizing measurements, dyed silk textiles appeared to have a higher deodorizing effect than cotton textiles. As for cotton textiles, those that had been treated with FeSO$_4$.7$H_2O$ and in the case of dyed silk textiles those that had been treated SnCl$_2$.2$H_2O$ recorded the highest deodorizing effect.

• Bulletin of the Korean Chemical Society
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• 제23권8호
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• pp.1067-1072
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• 2002

A new polystyrene-divinylbenzene resin containing 2-(2-thiazolylazo)-5-dimethylamino-phenol (TAM) functional groups has been synthesized and its sorption behavior for nineteen metal ions, including Zr(Ⅳ),Hf(Ⅳ) and U(Ⅵ) has been investigated by batch and column methods. The chelating resin showed high sorption affinity for Zr(Ⅳ) at pH 1-5 and U(Ⅵ) at pH 4. Some parameters affecting the sorption of the metal ions have been detailed. The breakthrough and overall capacities were measured under optimized conditions. The overall capacities of Zr(Ⅳ), Th(Ⅳ) and U(Ⅵ), which showed higher than the other metal ions, were 0.90,0.84 and 0.80 mmol/g, respectively. The elution order of metal ions at pH 4 was evaluated as Zr(Ⅳ) > Th(Ⅳ) > U(Ⅵ) > Cu(Ⅱ) > Hf(Ⅳ) > W(Ⅵ) > Mo(Ⅵ) > In(Ⅲ) > Sn(Ⅳ) > Cr(Ⅲ) > V(Ⅴ) > Fe(Ⅲ). Quantitative recovery of most metal ions except Zr(Ⅳ) was achieved using 2M HNO3. Desorption and recovery of Zr(Ⅳ) was successfully performed with 2 M HClO4 and 2 M HCl.

• 한국식품과학회지
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• 제28권1호
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• pp.90-98
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• 1996

한국산 사과의 대표적 품종인 뉴조나골드, 홍옥, 후지, 아오리와 Starking Delicious, Starkspur Red Delicious, Indo, Starkrimson Delicious, Golden Delicious, Yuko, Iwakkai, Orei와 시판되고 있는 100% 천연 사과 주스(5종)와 50% 사과과즙 음료(4종)의 무기질 함량은 다음과 같다. 사과에서는 Mn 0.20-2.52 ppm, Cu 0.10-1.03 ppm, Fe 0.24-9.88 ppm, Zn 0.09-1.06 ppm, Mg 21.08-99.00 ppm, Ca 15.16-99.56 ppm, K 842.10-1788.10 ppm, Na 10.32-40.53 ppm, P 24.43-90.97 ppm, Pb nd-98.05 ppb, Cd nd-36.08 ppb, Cr 2.25-123.76 ppb이었으며 K, Na, Mg, Ca 등은 함량이 높고 Pb, Cd, Cr은 미량 존재하며 품종간, 지역간 함량 차이가 크다. 또한 Mn, Cu, Fe는 품종간 유의차가 두드러지며, Pb, Cd, Cr 함량은 유의차가 없다. 뉴조나골드 품종에서는 분포가 다양하다. 전반적으로 아오리, 홍옥에서 함량이 높고, 후지 품종은 대부분 함량이 낮다. 산지별 유의성 검정을 실시한 결과, Mn, Cu, Fe는 유의차가 두드러진다. Mg, Ca, Pb, Cd, Cr, Na는 유의차 없다. 강원도 지역에서 품종별로 유의적인 차이가 두드러지게 나타나고 있다. 산지별 비교시 전반적으로 강원도, 경상도 사과의 함량이 높으며 전라, 충청 지역은 상대적으로 함량이 낮다. 100% 시판 주스의 경우 Mn 0.37-0.99 ppm, Cu 0.10-0.61 ppm, Fe 0.19-3.70 ppm, Zn 0.20-1.77 ppm, Mg 24.47-49.56 ppm, Ca 14.42-42.30 ppm, Na 14.71- 52.58 ppm, K 785.07-1440.30 ppm, P 22.01-63.56 ppm, Pb nd- 95.55 ppb, Cd nd-17.65 ppb, Cr 8.60-110.98 ppb으로 표준 주스와 100%시판 주스의 함량을 비교하면 Cu, Mg, K, Ca, Fe 함량은 표준 주스에서 더 높다. Zn, Na은 표준 주스에서 함량이 작다. Mn, Cd, Pb, Cr은 사과와 주스에서 유의차가 없다(p>0.05). 100% 시판 주스와 50% 시판 주스를 비교하면 Zn, Pb, Ca, Cr, Fe 성분은 100% 시판 주스에서 함량이 작다. K는 100% 시판 주스에서 함량이 더 많다 Fe, Pb는 100% 시판 주스에서 유의적으로 함량이 작으며 Na, Cd, Mg는 유의차가 없다(p>0.05).

• 한국세라믹학회지
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• 제25권4호
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• pp.408-414
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• 1988

This thesis is 2nd thesis from "Mechanism of Intercalation Compounds in Graphite with Hydrogen sulfate(J. Korea Cer. Soc. Vol. 22. No.6, 1985). We have oxidized natural Graphite flakes(0.1~0.2mm., Kropfm hl passau in Deutchland. S40) with a solution of CrO3 in H2SO4. Whilst persulfate ions were intercalated, too, below 7$^{\circ}C$, no evidence for intercalation of a peroxo compound was found at 22$^{\circ}C$. The reaction was interrupted after various times by filtering and washing with concentrated H2SO4. X-ray diffraction showed that the 2nd stage compound had already been formed after 2 minutes. We could only follow further oxidation to the blue stage compound which was completed after 35 minutes. We have found six distinct intermediate stage between 2nd stage and 1 stage. Experiments are described on the formation of intermediate stage color and X-ray diffraction analysis.ysis.

• 대한가정학회지
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• 제40권11호
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• pp.131-140
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• 2002

The purpose of this study is to investigate the dyeability, antibacterial activity and deodorization on cotton and silk fabrics dyed with extracted solution from gardenia. The results are as follows: 1. The K/S value of silk fabrics was higher than that of cotton fabrics, and the K/S value was slightly increased by mordanting with $SnCl_2.2H_2O$ and $K_2Cr_2O_{7}$ on cotton and silk fabrics. 2. Cotton fabrics showed yellow from GY to Y and silk fabrics showed yellow or reddish yellow from GY to Y-YR. 3. The fastness to washing of cotton fabrics was very poor and that of silk fabrics was middle or lower, excluding good fastness to wool contamination of both fabrics. The fastness to dry cleaning and rubbing of both fabrics was very good. The fastness to perspiration of cotton fabrics was middle or higher, but that of silk fabrics was much better than that of cotton fabrics. The fastness to the light of both fabrics showed very poor with 1 grade. Dyeing fastness was slightly improved by mordanting on both fabrics. 4. Silk and cotton fabrics did not show antibacterial activity, but the activity of silk fabrics was higher than that of cotton fabrics. The antibacterial activity was increased by mordanting. 5. The deodorization of dyed cotton and silk fabrics was excellent, and that of silk fabrics showed better than that of cotton fabrics.

• 환경위생공학
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• 제9권2호
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• pp.8-23
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• 1994

During the period from Mar., 1991 to Feb., 1992 66 tSP samples were collected by Hi volume air sampler at 1 sampling site in Seoul and the amount of concentration of 21 components(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Al, Ba, Ca, Cd, Cr, Cu, Fe, It Mg, Mn, Na, Ni, Pt Si, Ti, Zn, Zr ) were measured. And monthly and seasonal variation were surveyed and the principal component analysis( PCA ) were carried out with respect to these amount of pollutants, minimum of visibility and radiation on a horizontal surface. The total amount of soluble ion in water was high in order o(SO$_{4}$$^{2-}$> NO$_{3}$$^{-}$> N%'>Cl$^{-}$ and metal ion was high in order of Na> Ca>Si> Fe> Al> K> Mg> Zn> Pb> Cu>Ti> Mn > Ba> Cr> Zr> Ni> Cd. There was Seasonal variation in concentration for SO$_{4}$$^{2-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Na, Al, Ca, Bt Mg, Fe and Si. It was assumed that the components of the highest concentration on April were depend on yellow sand and the frequency of wind velocity and direction. As the results of PCA, the amount of pollution components was able to characterized with two principal components(Z$_{1}$, Z$_{2}$ ). The first principal components Z$_{1}$ was considered to be a factor indicating the pollutants originated from natural generation and The second principal components Z$_{2}$ was considered to be a factor indicating the pollutants originated from human work. The monthly concentration of pollutants in ISP, minimum of visibility and radiation on a horizontal surface was possible to evaluate by the use of these two principal components Z$_{1}$ and Z$_{2}$ .

• 한국표면공학회지
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• 제48권6호
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• pp.354-359
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• 2015

Stainless steel has poor corrosion resistance in marine environment due to the breakdown of a passive film caused by chloride. It suffers electrochemical corrosion like pitting corrosion, crevice corrosion, and stress corrosion crack (SCC) in marine environment. In general, it indicates that the passive film of $Al_2O_3$ has better corrosion resistance than that of $Cr_2O_3$ in seawater. This paper investigated the damage behavior 304 stainless steel and hot-dip aluminized 304 stainless steel in seawater solution. Various electrochemical experiments were carried out including potential measurement, potentiodynaimic experiment, Tafel analysis and galvanostatic experiment. As a result of anodic polarization experiment, higher pitting damage depth was indicated at 304 stainless steel than hot-dip aluminized 304 stainless steel. In addition, relatively higher corrosion current density was shown at hot-dip aluminized stainless steel as a result of Tafel analysis.