• 접착 및 계면
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• 제4권3호
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• pp.1-8
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• 2003

철판에 도금한 아연을 구리이온으로 치환하는 치환도금법과 철판에 직접 구리를 증착하는 진공증착법으로 두께가 다른 구리박막 피복철판을 제조하여 배합고무와 접착성질을 조사하였다. 구리박막 피복철판과 배합고무의 접착세기는 제조방법에 관계없이 구리박막 두께에 따라 결정되었다. 구리박막이 75 nm보다 얇으면 안정한 접착층이 형성되어 황동판에 못지 않게 고무와 강하게 접착되었으나, 90 nm보다 두터우면 구리황화물이 지나치게 성정하여 접착세기가 약하였다.

• Elastomers and Composites
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• 제53권3호
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• pp.109-123
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• 2018

The effect of the silica content on the state and properties of silica-filled styrene-butadiene rubber/butadiene rubber (SBR/BR) compounds containing coupling and dispersion agents was evaluated by varying the content of silica from 50 to 120 phr. Bis-[(triethoxysilyl)propyl] tetrasulfide (TESPT) and zinc 2-ethylhexanoate (ZEH) were used as the coupling and dispersion agents, respectively. The maximum silica content in the pristine material was 80 phr, which increased to 120 phr upon the addition of TESPT and ZEH. The incorporation of TESPT considerably improved most of the rubber properties due to its coupling action and the suppression of silica flocculation, while further addition of ZEH resulted in additional improvements. The properties of the rubber compounds with different silica contents can be fully explained either by an enhancement of the rubber-silica interactions or by their deterioration due to an excessive amount of silica aggregates.

• 대한지역사회영양학회지
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• 제1권2호
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• pp.201-214
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• 1996

This study was aimed at evaluating the lipid status of 122 pregnant women, who were attending peripheral community clinics in low-income areas and were vulnerable in terms of public health, by anthropometric measurements, estimating dietary intakes and analyzing serum lipids content and fatty acids composition. Regarding the skinfold thickness, it has increased more significantly in suprailliac than in triceps, biceps, subscapular, which means body fat has been accumulated in central parts more than in distal parts of the pregnants. It is found that intakes of energy, protein, lipid and carbohydrate are desirable while calcium, zinc and copper are low and sodium is excessive. Regarding dietary fat intake, the energy $\%$ of fat was within the same range as RDA(20%) for adults, but energy $\%$ intake from each fatty acid was usually low, especially energy % of monoun-saturated fatty acid intake was below RDA for adult women. And intake ratio of $\omega$6$\omega$3 fatty acids was desirable. Accordingly, it is thought that dietary fat intake was balanced in quality. Serum lipids concentrations were increased with the length of pregnancy and were higher as compared with non-pregnant women. Polyunsaturated fatty acids, especially $\omega$6 fatty acids, have gradually decreased with the length of pregnancy. Serum lipids content and fatty acids composition were not greatly influenced by dietary fat but serum free fatty acid level was negatively related to energy, carbohydrate, fatty acids and cholesterol intake. On the basis of the above results, it can be predicted that lipid metabolism for mother and fetus is changed by pregnant status and multilateral research on maternal nutrition in terms of areas and income levels will have to be made. (Korean J Community Nutrition 1(2) : 201-214, 1996)

• Food Quality and Culture
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• 제1권1호
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• pp.46-57
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• 2007

The purpose of the present study was to examine the nutrient intake status of elderly dementia patients. We surveyed the dietary intake of 50 demented elderly patients receiving a regular diet, who were hospitalized in a geriatric hospital in Yongin, Gyeonggi-do. The average age of the subjects was $79.6{\pm}6.5$ for the males and $80.5{\pm}6.3$ for the females. The average heights were $169.5{\pm}6.0\;cm$ (males) and $154.6{\pm}5.2\;cm$ (females), and the average weights were $58.5{\pm}7.4$ (males) and $51.7{\pm}8.9\;kg$ (females). Depending on the type of dementia, the male patients showed significant differences in their intakes of vegetable protein, fiber, total iron, and non-heme iron between the Alzheimer's disease (AD) and the vascular dementia (VD) groups, and the female patients showed significant differences in their intakes of total protein, phosphorus, zinc, and vitamin $B_6$ between the two groups. The male patients showed significant differences in their intakes of animal-source calcium and carotene according to ability to self-feed. According to physical activity, the male patients showed significant differences in vegetable fat and vitamin A intake, and the females showed significant differences in their intakes of total protein, animal protein, fiber, ash, total calcium, vegetable-source calcium, animal-source calcium, phosphorous, total iron, non-heme iron, heme iron, sodium, vitamins $B_1$, $B_2$, $B_6$, niacin, vitamin C, folate, and potassium. We found that the patients consumed excessive protein, but low amounts of calcium, vitamin $B_2$, and folate. Also, the patients' physical activity abilities appeared to affect their nutrient intakes.

• 대한지역사회영양학회지
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• 제2권3호
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• pp.305-318
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• 1997

This study was aimed at evaluating the nutritional status of Korean lactating women, who were attending peripheral community clinics in low-income areas, by anthropometric measurement, estimating dietary intakes and analyzing the contents of breast milk components, serum lipid content and fatty acid composition. Regarding anghropometric measurements, maternal circumferences decreased significantly at the trunk but not at the limbs. The skinfold thickness on all regions had the tendency to decrease during lactation. It was found that intakes of energy, protein, lipid and carbohydrates were desirable while calcium, zinc, copper and vitamin A were low and sodium was excessive. The energy $\%$of fat was 22.41$\%$of the total energy which is higher than the RDA for adults but it is proper for lactating women, but energy $\%$ from each fatty acid was usually low and an intake ratio of $\omega$6/$\omega$3 fatty acids was desirable. Accordingly, it is thought that dietary fat intake was balanced in quality. Concentrations of the nutrients in matured human milk showed the same range as that reported form different regions with the exception of calcium and magnesium which were relatively low. Serum lipid contents were decreased with the time postpartum and the average serum lipid content of lactating women were similar to the normal range of adults. Serum polyunsaturated fatty acids. especially $\omega$6 fatty acids have gradually increased with the time postpartum, but the composition were not greatly influenced by dietary intakes.

• Journal of Nutrition and Health
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• 제39권7호
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• pp.692-698
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• 2006

The voluntary addition of vitamins and minerals to the appropriate foods may help reduce the risks associated with low intakes of these micronutrients, yet the potential of excessive intake, particularly for persons consuming very large amount of foods needs to be addressed. Using the Flynn's model to estimate the level of each vitamins and minerals that can be added safely to foods, maximum levels of fortification to conventional foods per 100 kcal portion were estimated. Critical factors in the Flynn's model included tolerable upper intake level (UL), each micronutrient intake at the $95^{th}$ percentile, the proportion of fortified foods in the diets of individuals, the proportion of foods to which micronutrients could be practically added, and a range of estimates for fractions of foods which might be actually fortified in each nutrient. Food vehicles included all foods except for fresh foods and alcoholic beverages, in general. With fortification of 50% of all potentially fortifiable foods, micrornutrients could be added safely to foods at levels per 100 kcal 1) > 100% Recommended Intake (RI) for vitamin $B_12$, 2) 1,200% RI for vitamin $B_1$ and niacin, 3) 1,000% $B_1$ for vitamins $B_2$ and $B_6$, 4) 400% RI for vitamin E, 5) 30% RI for calcium, 6) 20% RI for folic acid, iron and zinc, 7) 10% RI for manganese, 8) no fortification for magnesium, phosphorous and vitamin A, and 8) further consideration of vitamin D, copper and selenium due to insufficient evidence. Results of this study suggests a wide range of vitamins and minerals that can be added safely to foods in current diets of Koreans.

• Asian Pacific Journal of Cancer Prevention
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• 제16권1호
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• pp.9-21
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• 2015

Cancer, a serious public health problem in worldwide, results from an excessive and uncontrolled proliferation of the body cells without obvious physiological demands of organs. The gastrointestinal tract, including the esophagus, stomach and intestine, is a unique organ system. It has the highest cancer incidence and cancer-related mortality in the body and is influenceed by both genetic and environmental factors. Among the various chemical elements recognized in the nature, some of them including zinc, iron, cobalt, and copper have essential roles in the various biochemical and physiological processes, but only at low levels and others such as cadmium, lead, mercury, arsenic, and nickel are considered as threats for human health especially with chronic exposure at high levels. Cadmium, an environment contaminant, cannot be destroyed in nature. Through impairment of vitamin D metabolism in the kidney it causes nephrotoxicity and subsequently bone metabolism impairment and fragility. The major mechanisms involved in cadmium carcinogenesis could be related to the suppression of gene expression, inhibition of DNA damage repair, inhibition of apoptosis, and induction of oxidative stress. In addition, cadmium may act through aberrant DNA methylation. Cadmium affects multiple cellular processes, including signal transduction pathways, cell proliferation, differentiation, and apoptosis. Down-regulation of methyltransferases enzymes and reduction of DNA methylation have been stated as epigenetic effects of cadmium. Furthermore, increasing intracellular free calcium ion levels induces neuronal apoptosis in addition to other deleterious influence on the stability of the genome.

• Journal of Nutrition and Health
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• 제39권6호
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• pp.539-548
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• 2006

In recent years a concern of excessive intakes of vitamins and minerals from various sources is increasing, since there has been a marked increase in production and consumption of vitamin and mineral supplements and fortified foods. The purpose of this study was to assess the maximum exposure of vitamins and minerals from various sources including diet, fortified foods, and health functional foods among Koreans. As a result, the highest exposure group of most vitamins and minerals from diet was adults (30 - 49 years of age) according to 2001 Korean National Nutrition and Health Survey Report. Maximum dietary intakes of vitamin A, $B_1,\;B_2$, C, nicotinamide, calcium, phosphorus and iron were 0.5 - 7 times of the RDA for Koreans, 7th ed. Maximum intakes of vitamins and minerals from fortified foods by adults (20 - 59 years of age) were 8 - 760% of the Korean RDA. In addition, maximum exposure of vitamins and minerals from vitamin mineral health functional foods by middle aged people was 35 - 140% of the upper limits (UL: DRI for Koreans). As a consequence, maximum combined intakes of vitamin $B_6$, vitamin C, calcium, iron and zinc from the above sources including diet, fortified foods and vitamin mineral health functional foods were greater than the UL. These results would be applied for determining the safe upper limits of vitamin and mineral of health functional foods.

• 전기전자학회논문지
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• 제27권1호
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• pp.30-37
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• 2023

양자점 발광 다이오드(QD-LED)의 효율과 안정성 향상을 위해서 QD 발광층에 주입되는 전하의 균형을 이루는 것은 필수이다. 산화 아연(ZnO)은 최신 QD-LED에서 전자수송층(electron transport layer, ETL)을 구성하기 위해 가장 많이 사용되고 있으나, ZnO의 자발적인 전자 주입은 QD-LED의 성능을 크게 열화시키는 과도한 전자 주입을 유발한다. 본 연구에서는 자기조립단분자막(self-assembled monolayer, SAM) 처리를 통해 ZnO의 전자 주입 특성을 조절하여 QD-LED의 성능을 향상시켰다. 전하 균형도를 향상시킨 결과, SAM을 처리한 QD-LED는 SAM을 처리 안한 소자와 비교하여 내부 양자 효율(external quantum efficiency, EQE)이 25%, 최대 휘도는 200% 향상되었다.

• 한국식품위생안전성학회지
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• 제29권2호
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• pp.99-104
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• 2014

본 연구는 무기질이 강화된 식품(음료류, 면류, 시리얼류, 곡류가공품) 68건에 대하여 무기질류의 함량을 분석하여 표시량에 대한 검출량의 비율을 조사하였고 칼슘과 다른 무기질의 비율을 분석하였다. 칼슘, 철, 아연의 함량은 마이크로웨이브 장치로 분해 후 ICP-OES로 분석하였다. 칼슘을 강화한 음료류, 면류, 시리얼류, 곡류가공품 38건에 대한 칼슘의 검출량은 표시량의 82.2~293.1%이었다. 무기질류를 강화한 음료류, 면류, 시리얼류, 곡류가공품에 대한 철(42건)과 아연(24건)의 검출량은 각각 표시량의 83.3~301.0%, 90.1~314.1%이었다. 칼슘과 철의 분자량비는 과채주스 90.55(50.55~220.64), 과채음료 850.41, 혼합음료 553.49, 두유류 179.07(118.37~238.01), 국수 204.39(41.64~397.52), 유탕면류 296.97(121.64~868.88), 시리얼류 30.89(15.69~62.05) 그리고 곡류 가공품 7.73(0.22~49.92)이었다. 칼슘과 인의 중량비는 과채주스 1.44(0.96~1.98), 과채음료 1.92, 혼합음료 1.66, 두유류 4.23(2.25~7.72), 국수 1.14(0.28~1.97), 유탕면류 1.88(1.17~2.42), 시리얼류 1.29(0.87~2.92) 그리고 곡류가공품 0.30(0.06~1.57)이었다. 칼슘과 마그네슘의 중량비는 과채주스 1.85(0.87~5.04), 과채음료 28.72, 혼합음료 2.97, 두유류 5.27(2.93~9.36), 국수 3.97(1.34~7.57), 유탕면류 6.77(4.63~10.78), 시리얼류 4.40(2.30~12.55) 그리고 곡류가공품 1.17(0.23~7.48)이었다. 이와 같은 결과로 칼슘의 함량과 칼슘 강화식품에서 칼슘과 다른 무기질들의 비율에 대한 엄격한 관리가 필요하고 또한 과도한 영양 문제를 방지하기 위해 영양강화식품의 식품 표시 및 영양에 대한 더 많은 이해 방안이 모색되어야 한다는 것을 제안할 수 있다.