• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.14-14
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• 2018

This Camptotheca acuminata Decne. (CA), belonging to Nyssaceae, is a deciduous tree. and has been used as Traditional Chinese medicine since ancient times. The CA produces camptothecin a natural indole alkaloid, and reported to have anti-cancer effects. But the studies on biological activities of CA leaves are insufficient. Therefore, this study confirmed various biological activities such as antioxidant, antidiabetic, anticancer, antiinflammatory and metabolism analysis by HPLC-MS/MS of CA leaves. The $RC_{50}$ values of DPPH radical scavenging activity of ethyl acetate fraction, n-Butanol fraction, methanol extraction, water fraction and n-Hexane fraction were $12.23{\pm}0.01$, $15.93{\pm}0.42$, $55.12{\pm}0.45$, $56.29{\pm}4.15$ and $427.29{\pm}6.13ug/mL$, respectively. The $IC_{50}$ values of ${\alpha}$-glucosidase inhibitory activity of ethyl acetate fraction, n-Butanol fraction, methanol extraction, n-Hexane fraction and water fraction were $24.29{\pm}0.14$, $47.86{\pm}0.45$, $54.23{\pm}1.21$ $466.76{\pm}2.21$ and $623.91{\pm}9.67ug/mL$, respectively. The nitric oxide release activity of n-Hexane fraction, methanol extraction, ethyl acetate fraction, water fraction and n-Butanol fraction were $31.49{\pm}5.74$, $29.79{\pm}0.71$, $26.89{\pm}0.71$, $8.24{\pm}5.83$ and $7.75{\pm}4.08%$ at 25 ug/mL, respectively. The anti-cancer activity of n-Hexane fraction, methanol extraction, ethyl acetate fraction, water fraction and n-Butanol fraction were $31.49{\pm}5.74$, $29.79{\pm}0.71$, $26.89{\pm}0.71$, $8.24{\pm}5.83$ and $7.75{\pm}4.08%$ at 25 ug/mL, respectively. The ethyl acetate fraction activities showed higher biological activities than other fractions. Thus, Additional studies were conducted using ethyl acetate fraction. Metabolite analysis was performed using a LCMS-8040 triple quadrupole mass spectrometer. As a result, Five compounds (1-5) were identified in the ethyl acetate fraction of the CA leave. The identification of these compounds was generated by the analysis of fragmentation methods of the negative and positive ion modes. Five compounds were identified as gallic acid (1), chlorogenic acid (2), isoquercetin (3), astragalin (4) and camptothecin (5). These results suggest that the CA leave can be used for functional materials.

• Nuclear Engineering and Technology
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• 제53권6호
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• pp.1931-1938
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• 2021

Uranium ingot is produced by metallothermic reduction of uranium tetrafluoride using magnesium or calcium as reductant. Presence of oxygen containing compounds viz. uranyl fluoride and uranium oxide in the starting uranium fluoride has a significant effect on the firing time, final temperature of the charge, slag-metal separation and hence the metal recovery. As reported in the literature, the maximum tolerable limit for uranyl fluoride in the UF₄ is 2.5 wt% and limit for uranium oxide content is in the range 2-3 wt%. No theoretical or experimental basis is available till date for these limits. Analyses have been carried out in this study to understand the effect of UO₂F₂ concentration in the starting fluoride on the final temperature of the products and thus the reduction characteristics. UF₄ having uranyl fluoride concentration, less than as well as more than 2.5 wt%, have been investigated. Thermodynamic calculations have been carried out to arrive at a general expression for the final temperature attained by the products during calciothermic reduction of UF₄. Finally, an upper limit for the oxygen containing impurities has been estimated using the CaO-CaF₂ phase diagram.

• 대한지리학회지
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• 제39권3호
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• pp.444-456
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• 2004

최근 GIS 분야에서는 GIS와 동적 프로세스 모델링에 기반한 셀룰라 오토마타(CA)의 결합을 통한 공간모델링 연구가 활발히 진행되고 있다. 그러나 선행 연구에서의 CA 모델링은 해결하고자 하는 문제의 핵심이 되는 규칙을 찾아내는 기능은 제공하지 못하고 있다. 본 연구에서는 GIS와 지식 발견 기법을 이용하여 공간 연관규칙을 추출하는 방법론을 제시하고 실제 사례에 적용하였다. 이러한 방법론의 제시는 CA 모델링의 기능을 더욱 향상시킬 것으로 기대된다. 또한 본 연구에서 사례로 적용한 도시지역 확장 외에 다양한 문제에 대한 활용이 가능할 것으로 판단된다.

• Journal of Applied Biological Chemistry
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• 제60권1호
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• pp.19-22
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• 2017

사골로부터 칼슘과 인의 용출량을 증가시킴과 동시에 칼슘의 흡수에 효과적인 비율로 칼슘과 인의 함량을 조절하기 위하여 초산과 구연산의 혼합효과를 조사하였다. 사골에 구연산과 초산을 각각 첨가하여 추출물을 제조한 결과, 구연산은 사골로부터 칼슘과 인을 유사하게 용출시키나, 초산은 인보다 칼슘을 선택적으로 용출시켰다. 초산 0.2 %와 구연산 0.1 %를 혼합하여 제조한 추출물은 초산 0.2 %의 결과에 비하여 칼슘의 용출량은 약 30 %($26.89{\rightarrow}34.22mg$) 증가하였으나 인의 용출량은 약 400 % ($3.57{\rightarrow}18.45mg$) 증가하였으며, 칼슘과 인의 비율은 7.53에서 1.85로 크게 개선되었다. 관능평가에서 맛과 전체적인 기호도는 0.2 % 초산+0.1 % 구연산을 첨가하여 제조한 시료가 증류수와 0.2 % 초산을 사용한 시료보다 우수하였다.

• Journal of Periodontal and Implant Science
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• 제30권3호
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• pp.527-538
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• 2000

Several extraction cases with advanced bone loss as a result of periodontal disease, root or labial bone fracture, extensive caries, and periapical lesions occur esthetic, functional problems and severe bone loss. Therefore, to treat these cases used several surgical methods and socket preservation among this therapies have been evaluated simple, effective and good prognosis in the implant placement. Socket preservation therapy have been used with barrier membranes or/and graft materials. Deproteinized bovine bone mineral have been evaluated ideal grafting materials. Recently, calcium-phosphate thin film coated bovine bone powders were developed in our country, but the study for these material wasn't reported. When two types of xenograft materials were implanted in extraction sockets of Beagle dogs, the effects of these were analyzed after 4 weeks and 8 weeks histological views. The results of this study were as follows. 1. In control groups, 4 weeks after implantation, the extraction sockets were filled with connective tissue which has dilated vessels and epithelial growth. And after 8 weeks, irregular connective bundles were observed. But new bone formation was not seen. 2. In Bio-Oss groups, epithelial growth was not seen and bone powder was covered with connective tissue fiber. New bone formation was found around the interproximal bone. There was no special change seen after 8 weeks, connective tissue fibers became more regular, and bone growth near bone powder was not made well. 3. In Ca-P BBP groups, epithelial cells didn't grow in the extraction sockets, there was a lot of new bone made around the bone powder after 8 weeks, new bone around bone powder was replaced with mature bone. It is thought that bone powder grafting into the extraction sockets is very useful for conservation of ridge, and Ca-P BBP is more effective in bone formation than Bio-Oss.

• 자원리싸이클링
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• 제25권5호
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• pp.50-56
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• 2016

질산용액중에서 Cyanex 301에 의한 은(Ag)의 추출 거동을 고찰하였다. Ag의 추출에 영향을 미칠 수 있는 질산 농도, 추출제 농도, 상비(O/A) 및 혼합추출제 효과 등에 대하여 조사하였고, Ca, Al, Fe, Zn, Sr 등 불순물 성분과의 분리성에 대해서도 고찰하였다. 실험결과, 질산 3.0M 용액에서 5% Cyanex 301을 사용할 경우에 Ag의 추출율 및 불순물과의 분리성면에서 가장 효과적이었다. 유기상중의 불순물 제거를 위해서 4.0 M이하 염산용액에서 세정을 실시하는 것이 효과적이었고, 티오요소를 탈거제로 사용함으로써 순수한 Ag 용액을 얻을 수 있었다.

• Korean Chemical Engineering Research
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• 제51권6호
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• pp.733-738
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• 2013

퇴적토는 미사 및 점토와 같은 미세토의 함량이 높으며, 유기물질이 많으며, 완충능이 크기 때문에 퇴적토로부터 중금속을 제거하는 것은 매우 어렵다. 본 연구에서는, 중금속으로 오염된 퇴적토에서 중금속을 제거하기 위해 2 V/cm의 일정한 전압경사를 적용한 실험실 규모의 전기동력학적 (EK) 정화공법을 사용하였다. 실험을 위해 적용한 음극 전해질로는 0.1 M의 ethylenediaminetetraacetic acid (EDTA), citric acid (CA), $HNO_3$, HCl, 그리고 수돗물을 사용하였으며, 양극 전해질로는 수돗물을 사용하여 순환시켜 주었다. 음극 전해질로 CA를 사용한 실험군에서 Ni, Cu, Zn, Pb는 각각 초기와 비교하여 92.4, 96.1, 97.1, 88.1%의 중금속 제거효율을 보였다. 높은 전압경사를 적용하게 되면, 음극 전해질내에 citrate 및 EDTA가 퇴적토로 이동이 용이하게 되며, 그로 인해 중금속-킬레이트 화합물을 형성하여 중금속의 추출률을 높일 수 있었다. 이러한 결과를 바탕으로, 높은 전압경사를 적용한 EK 실험에서 음극 전해질로 EDTA 혹은 CA를 사용하면 퇴적토로부터 중금속을 효과적으로 추출할 수 있다고 판단된다.

• Applied Biological Chemistry
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• 제9권
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• pp.71-81
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• 1968

1) 생미강(生米糠)을 n-hexane으로 탈지(脫脂)한 탈지미강(脫脂米糠)에 희(稀) HCl 또는 희(稀) $H_{2}SO_4$를 혼합(混合)하고 가끔 저어주면서 $8{\sim}12$ 시간(時間)동안 두어서 phytin을 침출(浸出)시키고 여과(濾過)하여서 침출액(浸出液)을 얻었다 .다음에 침출액(浸出液)을 염기(鹽基)로 중화(中和)하여서 phytin을 침전(沈澱)시키고 여과(濾過)하여서 phytin을 분리(分離)하였다. 이와 같이 하여서 탈지미강(脫脂米糠)으로부터 phytin을 분리(分離)함에 있어서의 여러 가지 조건(條件)에 관(關)하여 기초(基礎) 실험(實驗)을 하여 다음과 같은 결과(結果)를 얻었다. 2) 침출용(浸出用) 산액(酸液)으로써는 0.3% HCl이 좋았다. 탈지미강(脫脂米糠)에 희산(稀散)을 작용(作用)시키면 phytin 이외(以外)로 희산(稀散)에 가용성(可溶性)인 단백질(蛋白質) 당류(糖類), Vitamin B 군(群), 색소(色素)등도 상당량(相當量) 즉 탈지미강(脫脂米糠)의 $18{\sim}19%$가 침출(浸出)되어 나온다. 0.3% HCl 때 침출고형물(浸出固形物)은 탈지미강(脫脂米糠)의 30%이다. 탈지미강중(脫脂米糠中)의 염기성(鹽基性) 물질(物質)의 침출(浸出) 속도(速度)는 phytin의 그것과 차이(差異)가 있다. phytin은 탈지미강(脫脂米糠)과 희산액(稀酸液)을 혼합(混合)한 후 $1{\sim}5$시간(時間) 사이에서 주(主)로 침출(浸出)되어 나온다. 3) 침출용(浸出用) 산액량(酸液量)은 탈지미강(脫脂米糠)의 $8{\sim}10$ 배량(倍量)이 좋고 침출(浸出) 시간(時間)은 실온(室溫)에서 $8{\sim}12$ 시간(時間)이면 충분(充分)하다. 침출(浸出) 온도(溫度)는 $20{\sim}30^{\circ}C$가 좋고 그 이상(以上)이 되면 phytase의 작용(作用)이 활발(活潑)하여지므로 침출량(浸出量)이 저하(低下)된다. 4) 침출용(浸出用) 산(酸)으로써는 HCl를 사용(使用)할 때가 $H_{2}SO_4$를 사용(使用)할 때보다도 phytin 침출량(浸出量)이 많다. 0.3% HCl를 탈지미강(脫脂米糠)의 8배량(倍量) 쓰고 실온(室溫)에서 12시간(時間) 침출(浸出)시키였을때 phytin 침출율(浸出率)은 11.34%로써 이론치(理論値)의 93%였다. 5) phytin를 침전(沈澱)시키기 위한 침출액(浸出液)의 중화제(中和劑)로써는 포화(飽和) $Ca(OH)_2$ 용액(溶液)이 좋다. 침출액(浸出液)을 포화(飽和) $Ca(OH)_2$ 용액(溶液)으로 pH 7.0까지 중화(中和)하였을 때에 phytin 침전율(沈澱率)은 이론치(理論値)의 94.77%였다. 중화제(中和劑)로써 NaOH, KOH, $NH_{4}OH$를 쓸 때는 중화도(中和度)에 관계없이 침전(沈澱)이 대단히 불충분(不充分)하였다. 중화도(中和度)는 pH $6.8{\sim}7.0$이 좋다. 중화제(中和劑)로써 $NH_{4}OH$를 썼을 때가 phytin 침전(沈澱)이 제일 희고 여과(濾過)도 비교적(比較的) 쉽게 잘 되었다. 6) pH $6.0{\sim}7.2$에서 각(各) 용해도(溶解度)는 다음과 같다. K-phytate〉$NH_{4}-phytate$ > Na-phytate > Ca-phytate.

• 한국환경보건학회지
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• 제24권3호
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• pp.1-5
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• 1998

A spectrophotometric method was developed for the acidic solution stripped after an extraction of 0.5 to 2.5 ppm of Lead(II) from 50 mL of $Na_2S_2O_3$ solution into chloroform as the ion-pairs formed between their thiosulfate complexes and alkylamine, Aliquat336. Pb(II) in the stripped solution forms an complex with DDTC in pH 7.3 buffer solution, and was developed in yellow by copper replacement. The ydlow-colored solution have the maximum absorbance at 435 nm in the measurement of absorbance by UV-Visible spectrophotometer. The interference ions such as Fe(III), Hg (II), Al(III), Co, Cu, Ni, Zn, Ca, Sn, have great effects on the extraction, but they were overcomed by the usage of adequate masking agents before an extraction. At last, a good result was obtained in applying this method to synthetic water.

• Journal of the Korean Wood Science and Technology
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• 제13권3호
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• pp.49-53
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• 1985

The effects of pre-treatments, the hot water extraction of wood meal and the addition of chemical ($CaCl_2$) to wood-cement water system on the properties of wood-cement composite such as modulus of rupture (MOR), modulus of elasticity (MOE), water sorption ratio and swelling ratio of resulting boards were studied in this experiment. The wood meals through 0.83mm(20 mesh) and retained on 0.42mm(35 mesh) screen were prepared from Pinus densiflora S. at Z. and Larix leptolepsis G. For hot water extraction, 500 grams of wood meal for each species were heated to boiling with 1,500ml of distilled water in 2-liter beaker for 6 hours. Every 2 hours, the wood meals were washed with boiling distil1ed water and reheated to boiling again. After 6 hours boiling, the boiled wood particles were collected by pouring this particles on 200 mesh screen. The collected particles then washed twice with hot distilled water and dried for 24 hours in an oven at $109{\pm}20^{\circ}C$. A mixture of 663.4 grams of cement with 331.7 grams of wood meal based on oven-dry weight were dry-mixed in a plastic vessel. The mixture was kneaded with 497.6ml of distilled water in the ratio of 1.5ml of water to a gram of wood meal. To add calcium chloride to the mixture as an accelerator, $CaCl_2$ 4% solution by weight per volume, was added to pine-or larch-cement board in the ratio of 3% to cement weight. To set wood-cement board, this mixture was clamped at 30cm ${\times}$ 30cm, in thickness of 1.5cm for 3 days at room temperature, declamped and then placed at open condition for 17 days. The target density was 1.0. The four specimens sized to 5cm in width and 28cm in length were used for MOR and MOE test for each treatment. After MOR test, the tested specimens were cut to the size of 5cm ${\times}$ 5cm for water sorption and swelling test. The twenty specimens used to measure the water sorption ratio (soaking 24 hours) and ten of these were used for swelling ratio measurement The results obtained were as follows: 1) Larch was not suitable for wood-cement boards because larch-cement board developed no strength, but pine showed 97.9kg/$cm^2$ by hot water extraction. 2) To increase MOR, hot water extraction was more effective than the addition of $CaCl_2$ in pine and larch because the $CaCl_2$ addition was seemed to speed up the ratio of cement hydration without reacting with the wood substances. 3) The water sorption ratio was lowered by the addition of $CaCl_2$ to wood-cement system because the chemical additive accelerated the rate of cement hydration. 4) In pine-cement board, the swelling ratio from 0.37 to 0.42 percent was observed in length and the swelling ratio from 0.88 to 2.0 percent in thickness. As a rule, the swelling ratio of wood-cement board was very low and the swelling ratio in thickness was higher than in length.