• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.219-222
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• 2004

The effects of short fiber and particle hybrid reinforcement on fatigue crack propagation behaviors in aluminum matrix composites have been investigated. Single and hybrid reinforced 6061 aluminum containing same 20 $Al_2O_3\;volume\%$ with four different constituent ratios of short fibers and particles were prepared by squeeze casting method and tested to check the near-threshold and stable crack growth behavior. The fatigue threshold of the composites increased with portion of particle contents and showed the improved crack resistance especially in low stress intensity range. Addition of particle instead of short fiber also increased fracture toughness due to increase of inter-reinforcement distance. These increase in both fatigue threshold and fracture toughness eventually affected the fatigue crack growth behavior such that the crack growth curve shift low to high stress intensity factor value. Overall experimental results were shown that particle reinforcement was enhanced the fatigue crack resistance over the whole stress intensity factor range.

• 생약학회지
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• 제24권3호
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• pp.219-222
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• 1993

An antihyperglycemic compound in a model of alloxan induced diabetic rats was isolated from the root bark of Aralia elata. The compound identified to be oleanolic acid $28-O-{\beta}-_D-glucopyranoside$ was active at a dose of 100 mg/kg p.o. in the rats. It also has increased the contents of liver glycogen which were lowered by injection of alloxan in the rats.

• Journal of the Korean Wood Science and Technology
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• 제39권4호
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• pp.370-380
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• 2011

본 연구는 녹차 생잎 채취지의 토양의 성질과 채취시기별(우전-세작-중작) 녹차 생잎에 대한 화학성분 및 무기물 성분을 분석하였다. 먼저 조사지역의 토양의 성질을 살펴보면 대부분이 배수가 양호하고 인산이 풍부한 사양토와 양토로 구성되어 있었다. 녹차 생잎에 대한 성분 분석에 있어서는 섬유질, 탄닌, 비타민 C와 총카테킨 함량은 채취시기가 늦어질수록 증가한 반면 총질소, 총아미노산, 데아닌, 카페인 등은 대체로 감소하는 경향을 보였다. 무기물 함량에 있어서는 채취시기가 늦어질수록 Mg, Ca, Mn은 증가하였으나 Na, K, B는 감소하였다. 그리고 화학성분 중 총질소, 엽록소, 총유리아미노산, 데아닌, 카페인, 총카테킨과 무기물 중 나트륨, 마그네슘, 칼슘, 붕소, 세레늄에 있어서는 우전과 세작 간에 거의 함량 차이를 보이지 않았다.

• Preventive Nutrition and Food Science
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• 제17권2호
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• pp.141-151
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• 2012

The objectives of this research were to evaluate antioxidant activities and nutritional components, including phenolic acid, catechin, organic acid, sugar, and amino acid, of persimmon juice from persimmons grown in different regions around Korea. Persimmon (Diospyros kaki) exhibits potent antioxidant effects in DPPH, ABTS, reducing power, and FRAP methods of analysis. The levels of nutritional constituents showed significant differences among all the samples. In particular, tartaric acid, glucose, gallic acid, epicatechin gallate and aspartic acid were observed to be the predominant component for each of their general chemical groups, with total average contents of 1876.51 mg/kg, 62.69 g/kg, 12.73 mg/kg, 208.99 mg/kg, and 31.84 mg/100 g, respectively. Interestingly, persimmons from the Hadong region presented the highest sugar (130.60 g/kg), phenolic acid (42.27 mg/kg), and catechin (527.97 mg/kg) contents in comparison with other regional samples. Moreover, this location exhibited the greatest antioxidant activity with highest total phenolic (298.01 mg GAE/kg) and flavonoid (32.11 mg/kg RE) contents. Our results suggest that strong antioxidant activities of persimmons correlate with high phenolic acid and catechin contents, particularly gallic acid and epicatechin gallate. Additionally, these two compounds may be key factors when considering the useful ingredients of persimmon.

• 한국토양비료학회지
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• 제43권3호
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• pp.296-303
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• 2010

Chromium as a constituent of rocks occurs naturally in the environment in varying concentrations. However, the human activity has changed the geochemical cycle of chromium in the environment and has caused the chromium accumulation in soils. Korean soils revealed a wide range of chromium contents depending on parent material and land use. The total chromium contents of volcanic ash soils in Jeju, which were determined using $HNO_3$ + $HClO_4$ + HF, ranged from 434 to 1,164 mg $kg^{-1}$. The 'ecological' total chromium contents extracted using conc. HCl + conc. $HNO_3$ (aqua regia) in the same soils varied in a lower range of 50-189 mg $kg^{-1}$ (averaged percentage of aqua regia contents in $HNO_3$ + $HClO_4$ + HF contents: 14.9%). Serpentine soils in Andong showed a 'ecological' total chromium content of 309 mg $kg^{-1}$ and against it granitic soils in Andong only 20 mg $kg^{-1}$. In uncontaminated forest soils of Korea, the 'ecological' total chromium contents varied from 4.89 to 106 mg $kg^{-1}$ and the soluble chromium contents determined using 0.1 M HCl ranged from 0.01 to 0.64 mg $kg^{-1}$ (averaged percentage of 0.1 M HCl contents in aqua regia contents: 0.4%). Arable lands contained more soluble chromium than reported in forest soils (averaged soluble chromium: 0.36 and 0.09 mg $kg^{-1}$, respectively). In particular, the soluble chromium contents in greenhouse, orchard and upland soils were higher than in contaminated soils near mine and industrial site (maximum contents: greenhouse 15.3 mg $kg^{-1}$; upland 12.1 mg $kg^{-1}$; orchard 8.29 mg $kg^{-1}$; mine site 4.76 mg $kg^{-1}$; industrial site 2.80 mg $kg^{-1}$). On the basis of these results a accumulation of chromium in some specific arable lands can be assumed, probably by long-continued applications of fertilizers or soil amendments containing chromium. In Korean Enforcement Decree of the Soil Environment Conservation Act soil standards for total chromium do not exist yet.

• 한국식품조리과학회지
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• 제11권4호
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• pp.386-395
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• 1995

미나리(Oenanthe javanica D.C)의 향기성분의 추출방법, 부위별 및 열처리 방법에 따라 미나리의 향기 성분을 분석한 결과는 다음과 같다. 수증기 증류법에 의해 추출된 성분은 23종의 성분, Head space법에서는 8종의 성분, Ether 추출법에서는 16종의 성분, Tenax-GC법에서는 9종의 성분이 확인되어 향기성분 조성은 추출방법에 따라 상당한 차이를 나타냈고, 수증기 증류법에 의해 추출하였을때 가장 많은 종류의 성분이 검색되었다. 부위별 미나리 향기성분을 분석한 결과, 향기성분의 함량은 줄기와 잎에서 각각 41.71 mg%, 85.37 mg%로 잎에서의 함량이 줄기보다 더 높았다. 줄기 부위에서는 hydrocarbon류 14종, aldehyde류 5종, alcohol류 4종으로 23종의 성분을 잎 부위에서는 hydrocarbon류 21종, aldehyde 5종, alcohol류 4종, ester 1종으로 31종의 성분을 확인하였으며, 잎 부위가 줄기에 비하여 비교적 다양한 종류의 향기 성분이 검출되었다. 줄기에서는 octanal 함량이 가장 높았고, limonene, sabinene, -terpinene, -myrcene 함량이 높았으며, 잎에서는 octanal 함량이 가장 높았고, isobicyclogermacrene, limonene, -farnesene, undecaethiol, -terpinene, sabinene, elemene, -myrcen 함량이 높았으며, 이들이 미나리의 중요한 향기성분이라 할 수 있다. 또한 열처리 방법에 따라 미나리의 향기성분 조성이 변화되었으며, 1000 $m\ell$에서 열처리한 미나리가 생시료 미나리의 향기성분과 가장 유사하였고 향기 성분 함량이 가장 높았다.

• 한국식품영양학회지
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• 제22권3호
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• pp.352-356
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• 2009

흑후추와 백후추 원두에서 HPLC에 의한 piperine 함량, 가열처리 전후의 시료에 대한 Soxhlet법을 이용한 휘발성 기름성분 함량, SDE(Linkens-Nikens type simultaneous steam distillation and extraction apparatus)법을 이용한 총 휘발성 물질 함량 등을 측정하였다. 그 결과, 흑후추와 백후추의 구성성분차이, 인도네시아와 인도의 산지 기후조건 및 품종 차이 등에 따른 편차는 인정되었으나 전체적으로 일정한 범위 내에서 차이를 나타내었다. 후추에서 맛의 차이는 맛 성분의 차이보다는 휘발성 물질의 함량 차이가 큰 영향을 미쳐 냄새를 일반적으로 맛으로 착각하는 경향이 있는 것으로 판단된다. 이로부터 상호간의 측정결과를 비교평가해 본 결과 일정 수준의 비례적 관계를 갖는 것으로 나타나 현장의 품질관리 등에서 간편하고 신속하게 결과를 측정할 수 있는 Soxhlet법에 의한 휘발성 기름 성분 함량 측정법을 후추의 중요한 품질평가 방법의 하나로 활용할 수 있을 것으로 기대되는 결과를 얻었다.

• 한국초지조사료학회지
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• 제8권3호
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• pp.169-174
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• 1988

An experiment was conducted to determine the feeding value of Arundinella hirat silage making by different methods ie., added starch 3%, formic acid 1% (FA), anhydrous ammonia ($NH_3$) 3%, and dried poultry waste (DPW) 3%. The samples were analyzed organic acid, cell wall constituent (NDF), cell contents (NDS), lignincutin-silica (ADL), hemicellulose (H: CHO) and in vitro dry matter digestibility (DMD) by pepsin-cellulase technique. The feeding value of silages were compared with corn siiage. The results are summarized as follows; 1.Formic acid treated to silage was lower pH(4.0), but anhydrous ammonia (8.37) and DPW added silage (8.72) were higher than that of the other treatment silages. 2.Fermentative quality of corn silage, starch, DPW, $NH_3$, control and FA treated silage were marked 100,81, 77,63,62 and 58, respectively. 3.Silage with $NH_3$, (23.57%) and DPW (10.42%) of content of protein were higher than that of other treated silages. 4.Silage with $NH_3$, was significantly lower contents of NDF, but did not ADF of among the treated silages. 5.In the contents of ADL, starch added silage was significantly decreased (p < 0.05), but did not the other treatment. 6.DMD of in vitro by pepsin-cellulase of silage with starch was increased three folds as equal to corn silage but did not increased the other treated silages. 7.Correlationship of latic acid an total acid, and NDS were a positive but lactic acid and NDF was a negative correlation.

• 한국식품영양학회지
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• 제35권6호
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• pp.521-530
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• 2022

This study was conducted to compare the quality characteristics of commercial tofu products from the market in Korea. Seventeen types of commercial tofu samples were taken and their physicochemical properties, including soluble solid contents, salinity, pH, total acidity and moisture (total solid contents), were analyzed. The hardness of tofu was negatively correlated with the moisture contents of tofu (r=-0.667^**). The commercial tofu showed pH 5.80~6.24, total acidity of 0.016~0.034%, soluble solids of 1.50~3.45°Brix, salinity of 1.20~2.30%, and moisture content of 79.91~87.57%, respectively. All 17 tofu samples sold in the Korean market were prepared using crude MgCl₂ and sea water as a coagulant. The quality characteristics vary depending on the constituent's of soybeans, and the ratio and amount of coagulants of tofu used. The origin of soybean seeds affected the yellowness of tofu; tofu made from imported soybean showed a higher b value than domestic soybean. These results are expected to be useful for understanding trends in the domestic tofu industry.

• 한국식품조리과학회지
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• 제2권2호
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• pp.8-15
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• 1986

This study was carried out to investigate changes of the lipid contents and the fatty acid composition in shank during heating time and frozen storage. 1. The total lipid contents of raw shank were about 3.57% and decreased stepwise during heating time 30, 60, 90 min and frozen storage(24hrs) The contents of neutral lipid, glycolipid and phospholipid were 70.71%, 6.36%, and 22.93% in raw shank, and neutral lipid contents were decreased, whereas Phospholipid contents were increased according to heating tide. In frozen storage, neutral lipid and glycolipid contents were increased, while phospholipid contents were decreased. 2. Lipids of shank possessed about 8 kinds of fatty acid as the constituent by gas-liquid chromatography analysis. The main fatty acids were oleic acid, palmitic acistearic acid and linoleic acid: the fatty acids of total lipids in raw shank were 43.48% of oleic acid, 23.13% of palmitic acid,12.00% of stearic acid and 6.75% of linoleic acid. Also the fatty acids were 43.32% of oleic acid, 23.26% of palmitic acid, 9.30% of stearic acid 2.15% of linoleic acid in neutral lipid, 22.63% of oleic acid, 8.44% of palmitic acid, 11.98% of stearic acid, 27.01% of linoleic acidin glycolipid, 39.38% of oleic acid, 15.89% of palmitic acid, 15.55% of stearic acid, 17.49% of linoleic acid in phospholipid. 3. The fatty acid pattern of total lipid, neutral lipid, glycolipid and phospholipid was not any changes, whereas there was a difference in the fatty acid contents: palmitic acid and stearic acid of total lipid were decreased in the 30 min and 60 min heating but increased in 90min heating, and linoleic acid of neutral lipid was increased stepwise during heating time and frozen storage. Also palmiict acid of glycolipid was increased gradually and linoleic acid in heating time 30, 60 min was higher than 90 min and frozen storage. Among fatty acids in phoapholipid, oleic acid was increased during heating time, while decreased in frozen storage, and linoleic acid was not any change but linolanic acid was increased. UFA/SFA of phospholipid was the highest when heating time was 60 min. From above results, it was found that when heating time was 60 min beneficial nutritionally, comparing with changes of fatty acid composition according to the heating time aid frozen storage.