• 한국식품영양과학회지
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• 제27권6호
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• pp.1253-1261
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• 1998

Effects of dietary cholesterol and taurine supplementation on hepatic total and phospholipid fatty acid compositions were evaluated in rats fed one of the following semisynthetic diets for 5 weeks : control diet(CD, cholesterol free and taurine free diet); high cholesterol diet(HCD, CD＋1.5% cho lesterol); high cholesterol, high taurine diet(HCHTD, HCD＋1.5% taurine). Diet induced changes in hepatic total fatty acid compositions were very similar to those in hepatic phospholipid fatty acid compositions. The HCD significantly decreased the percentage of total saturated fatty acids(SFA), and increased the percentage of total monounsaturated fatty acids(MUFA) of hepatic total lipids and phospholipids as compared to the values for the control rats(p<0.001). HCHTD significantly elevated the percentage of $\Sigma$SFA and lowered the percentage of $\Sigma$MUFA compared to the values for the HCD(p<0.001). Percentages of hepatic total and phospholipid 18:3$\omega$3, 20:5$\omega$3, 18:2$\omega$6 and 20:3$\omega$6 were significantly higher in rats fed the HCD than the values for the control rats, and the percentages of their elongation and desaturation products(22:5$\omega$3, 22:6$\omega$3, 20:4$\omega$6, 22l:4$\omega$6 and 22: 5$\omega$6) were significantly lower in rats fed the HCD compared to those for the control rats. HCD significantly lowered the Δ5 desaturation(20:3$\omega$6⇒20:4$\omega$6) and Δ4 desaturation(22:4$\omega$6⇒22:5$\omega$6) indices, and the elongation index of $\omega$3 fatty acid(20:5 $\omega$3⇒22:5$\omega$3) in rat liver. HCHTD reversed the cholesterol induced changes in the compositions of $\omega$3 and $\omega$6 fatty acids. These results suggest the possibility that dietary cholesterol and taurine supplementations affect plasma and liver lipid levels, at least in part, by changing the hepatic phospholipid fatty acid compositions and thereby modulating the physical characteristics of the membrane and the activities of microsomal enzymes involved in lipid metabolism.

• Elastomers and Composites
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• 제43권4호
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• pp.241-252
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• 2008

올레인산으로 유기변성된 ZnAl-LDH(SO-ZnAl LDH)를 합성하여 브롬화 에폭시 수지(BER) 및 산화안티몬을 포함하는 난연 ABS 컴파운드에 첨가하였다. 난연 ABS 컴파운드는 동일방향으로 회전하는 이축압출기를 통해 제조되었고 난연성 및 기계적 성질을 측정하기 위한 시편으로 사출성형 되었다. ABS 나노복합재료의 XRD 패턴에서는 피크가 나타나지 않았다. SOZnAl LDH를 포함하는 난연 ABS 나노복합재료는 TGA 시험 결과 향상된 내열성을 보였다. 그러나, 난연 ABS 나노복합재료들은 UL 94 수직시험(1.6 mm 두께)시 등급을 얻지 못했다. BER를 1.5 wt% 이상 더 첨가한 경우들에서만 UL 94 V0 등급을 얻을 수 있었다. SO-ZnAl LDH의 첨가량에 비례하여 난연 ABS 나노복합재료의 노치드 아이조드 충격강도, 인장탄성률 및 신율은 증가하였으나 유동지수는 감소하였다.

• 한국염색가공학회지
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• 제18권4호
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• pp.20-27
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• 2006

Lyocell is a not only environmentally-friendly but also very advantageous fiber. When Lyocell is soaked in water, its wet tenacity does not decrease and elongation and moisture regain of it are better than cotton. However, one drawback of lyocell is its fibrillation. The fibrills of lyocell were generated during wet process such as scouring and dyeing deteriorates the dyeing color depth and the appearance of fabric. The purpose of this study was to decrease the fibrillation tendency of lyocell fabric using crosslinking agent, epichlorohydrine(ECH). The effects of NaOH scouring and ECH crosslinking were observed. The different types of ECH addition methods to lyocell and the various concentrations of ECH in crosslinking reaction onto dyeing characteristic and fibriallation were investigated. Weight loss and whiteness index of crosslinked lyocell by ECH were examined. K/S values of ECH treated lyocell fabrics dyed with reactive dye were measured and SEM images of untreated and treated lyocells were observed extensively to define the fibrillation tendency. The results were as follows ; 1) ECH treatment showed the effect of weight loss and scouring because ECH crosslinking reaction was conducted in alkaline condition. 2) The increase in ECH concentration from 5 to 30% does not affected K/S value changes. 3) ECH crosslinking can effectively prevent the fibrillation tendency of lyocell.

• 한국염색가공학회지
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• 제3권2호
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• pp.16-24
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• 1991

The textile fabric have the functions of sanitation, decoration, wearing style and washing in the practical use. Among various texitle fiber, silk has less utilities than synthetic fiber in practical use although silk has good benefits of the high quality. Thus no textile fiber, neither natural nor synthetic, has all the functions. In this sence, many blend yarns have been improved various functions of fabric. However, this has been disturbed with the problem of dyeing, especially in the case of blend fabric of silk. In this study, we dyed silk/PET blend fabric in one step useing one bath dyeing method by acid dyes/disperse dyes. The results of the experiments can be summarized as follows; 1) Yellow index of silk fabric treated at $130^{\circ}C$ increased about 7.8 (color difference 4.5 NBS) and whiteness decrease about 5%. 2) Both elongation and tensile strength of silk fabric treated at $130^{\circ}C$ of pH 5-6 decreased about 10% and tensile strength of silk spun yarn treated at $60^{\circ}C$ of pH 10 have little changed. 3) While silk/PET blend frbric dyeing, silk soiling of disperse dyes causes from difference of dyeing rate and degree of silk soiling with dyes. 4) Fastness and soiling of silk/PET blend fabric dyed by one bath dyeing method of acid dyes/disperse dyes was same as two bath dyeing method.

• 한국운동역학회지
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• 제21권2호
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• pp.207-213
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• 2011

The purpose of this study was to investigate changes in elastic properties of tendon structure of human ankle dorsiflexor following eccentric exercise. Six male subjects(age: $27.3{\pm}2.0$ years, height: $180.3{\pm}1.4$ cm, weight: $82.6{\pm}5.3$ kg) and three female subjects(age: $26.7{\pm}2.9$ years, height: $170.0{\pm}4.2$ cm, weight: $66.6{\pm}1.4$ kg) performed a single bout eccentric exercise consisting of 120 repetitions of maximum eccentric contractions. Prior to and following the eccentric exercise, isometric ankle dorsiflexion strength along with longitudinal ultrasound image of the tibialis anterior(TA) were collected. Muscle strength decreased about 30% after eccentric exercise. From the muscle strength vs. aponeurosis elongation curve, we obtained an index of stiffness. Stiffness of deep aponeurosis of the TA was assessed and found to be decreased from $87.4{\pm}33.56$ N/mm to $73.1{\pm}23.52$ N/mm. The results of this study suggest that decrease in stiffness of the TA aponeurosis following eccentric exercise might have significant implications to functions of the muscle-tendon complex and the involved joint motion and provide better understanding of eccentric exercise in the fields of training and rehabilitation.

• 한국강구조학회 논문집
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• 제9권2호통권31호
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• pp.193-204
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• 1997

본 연구에서는 먼저 강한 지진하중에 의해 발생되는 구조물의 파괴와 관련되어 있는 중요한 물리적 인자들의 상호관계를 정량화하기 위하여 반복하중을 받는 구조성분들에 대한 소성피로 문제에 대해서 검토하였으며, 강한 지진과 같은 극심한 반복하중하에서 구조성분들에 대한 극저사이클 피로파괴의 새로운 개념이 도입되었다. 또한 강구조물 요소에 대한 극저사이클 피로파괴 실험을 실시하였다. 실험은 수회에서 20회사이의 반복하중재하 과정에서 궁극적인 파괴를 실현하기 위하여 시도 되었다. 시험체는 H형강의 플랜지 단면처럼 강부재내의 않은 평판요소를 의미하는 직사각형 평판을 사용하였다. 이 시험체에는 비탄성좌굴, 소성신장 또는 이들 2가지의 조합이 발생한 후 부재가 완전히 파괴에 이를때까지 축방향 반복하중을 가하였다. 그 결과 극저사이클 피로하중에 의한 극한파괴상태는 구조요소단면 최외단에서의 최대변형율과 밀접하게 관련되어 있슴을 알 수 있었다.

• 한국재료학회지
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• 제14권10호
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• pp.713-718
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• 2004

To study the dynamic strain aging behavior of Zr-0.4Sn-1.5Nb-0.2Fe sample tube for nuclear fuel cladding in the range of pressurized water reactor (PWR) operation temperature, the tensile tests of the tube specimens, which had been finally heat-treated at $470^{\circ}C\;and\;510^{\circ}C$, had been carried out with the strain rate $1.67{\times}10^{-2}/s\;and\;8.33{\times}10^{-5}/s$ at the various temperatures from room temperature to $500^{\circ}C$. It was observed that the elongation of the specimens got shortened as the temperature increased from $200^{\circ}C\;to\;340^{\circ}C$. The specimens that were finally heat-treated at $470^{\circ}C$ showed a plateau more remarkably on the plot of yield strength-temperature than those heat-treated at $510^{\circ}C$. In the range of $310\sim400^{\circ}C$, the strain rate sensitivity of the specimens finally heat-treated at $510^{\circ}C$ was $30.4\%\sim33.7\%$ lower but the work hardening exponent index of the specimens was a little higher than that without dynamic strain aging effect.

• 폴리머
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• 제27권5호
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• pp.502-507
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• 2003

메탈로센 선형 저밀도 폴리에틸렌 (m-LLDPE)과 저밀도 폴리에틸렌 (LDPE)을 용응 블렌딩 방법으로 블렌드를 제조하여 열적 거동 및 물성을 관찰하였다. LDPE/m-LLDPE1 블렌드는 LDPE조성이 50% 이상이면 두 개의 용융 피크가 관찰된 반면 다른 블렌드들은 단일한 용융 피크를 나타내었다. m-LLDPE에서 공단량체 함량이 감소할수록 용융 온도와 상대 결정화도가 증가하였다. 공단량체 함량이 2 wt%인 m-LLDPE1이 초기 탄성률이 가장 높게 관찰되었고, 공단량체 함량이 증가함에 따라 감소하였다. 블렌드에서 조성에 따른 초기 탄성률의 변화는 상대 결정화도의 거동과 유사하게 나타났다. 블렌드의 파괴 신율은 LDPE/m-LLDPE1과 LDPE/m-LLDPE2 블렌드에서 평균값보다 낮은 파괴 신율을 나타내었었다. m-LLDPE2의 용융 지수가 가장 높게 관찰되었고 공단량체 함량이 증가함에 따라 감소하는 경향을 나타내었다.

• 한국작물학회지
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• 제44권2호
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• pp.122-128
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• 1999

Three rice cultivars, Namweonbyeo (early maturing), Hwaseongbyeo (medium maturing) and Dongjinbyeo (medium-late maturing) were trans-planted with 3 different seedling ages to investigate their growth habits and to improve the cultural method in paddy fields in the southern plain area of the Honam region in 1993. The 10-day old seedlings had more vigorous elongation of plant height and higher tillering ability but lower effective tiller rate, when compared with 35-day or 40-day old seedlings. Leaf area index and top dry weight were lower in 10-day old seedlings up to 40 days after transplanting but thereafter, were not different among seedlings ages. CGR was later in 10-day old seedlings, up to 30 days after transplanting, but in 30 to 40 days after transplanting, it was reversed. RGR was the highest in infant seedlings to 40 days after trans-planting, while in 50 days after transplanting, it was reversed. Panicle number and spikelet number per square meter were the highest in 40-day old seedlings, next highest in 35-day old seedlings and the lowest and in adult seedlings up to 40 days after transplanting, while spikelet number per panicle was vice versa. Milled rice yield did not vary significantly by seedling ages, but among the varieties, it was less in Hwaseongbyeo compared with Naweonbyeo and Dongjnbyeo.

• 폴리머
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• 제28권6호
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• pp.531-537
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• 2004

다양한 하프-에스터 아크릴레이트를 합성하기 위하여 다양한 산 무수물에 2-하이드록시에틸 아크릴레이트 (2-hydroxyethyl acrylate)를 반응시켰다. 합성된 하프-에스터 아크릴레이트에 지방족 에폭시 화합물인 네오펜틸글리콜 디글리시딜에테르 (neopentylglycol diglycidylether)를 반응시켜 광경화형 에폭시 변성 아크릴레이트를 제조하였다. 점도는 헥사하이드로프탈산 무수물 (hexahydrophthalic anhydride)을 사용하여 반응시킨 네오펜틸글리콜 디글리시딜에테르-헥사하이드로프탈산 무수물 (NP-HA)이 가장 높았다. 또한 헥사하이드로프탈산 무수물을 사용한 네오펜틸글리콜 디글리시딜에테르-헥사하이드로프탈산 무수물의 광경화물은 비교적 다른 산 무수물을 사용하여 제조한 에폭시 변성 아크릴레이트의 광경화물보다 경도, 인장 강도가 우수하였으며, 5% 무게 감소 온도도 높은 것으로 보아 열적으로 안정하다는 것을 알 수 있었다. 황변 지수값은 숙신산 무수물 (succinic anhydride)을 사용하여 반응시킨 네오펜틸글리콜 디글리시딜에테르-숙신산 무수물 (NP-SA)이 가장 낮았다.