• 한국진공학회지
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• 제7권s1호
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• pp.25-29
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• 1998

$SiO_2$ thin films embedded with Ge microcrystallites (Ge-$SiO_2$) were prepared by use of r.f. co-sputtering technique from a Ge, $SiO_2$ composite target. The size of Ge crystallites can been modulated by the experiment parameters. The optical absorption and non-linear optical properties of Ge-$SiO_2$ films were measured. The blue shift of the optical absorption edge, the saturated absorption and two-photon absorption under the condition of resonant absorption have been observed, and are discussed according to the quantum confinement effect.

• 설비공학논문집
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• 제13권12호
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• pp.1214-1222
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• 2001

The present study investigated the effect of diameter and length on the absorption performance of a vertical falling film type absorber using $LiBr-H_2$O solution of 60 wt%. The parameters were diameter of absorber (17.2, 23.4, 31.1 mm), length of absorber (771, 1150, 1528 mm), and film Reynolds numbers (50, 70, 90, 110, 130, 150). As the diameter of the absorber was increased, the absorption mass flux, Sherwood number, heat flux, and heat transfer coefficient were increased, in which Sherwood number and heat transfer coefficient were increased up to 13% and 30% respectively. As the length of the absorber was increased, the total absorption rate and heat transfer coefficient were increased by 37% and 35% respectively, while the absorption mass flux was decreased.

• 태양에너지
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• 제18권4호
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• pp.23-32
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• 1998

Fuel cells supply electric power and heat at work, and their exhaust gas is comparatively clear. So they are in the limelight as one of the co-generation systems which behave friendly with the environment. Fuel cells discharge both steam and hot water. Accordingly, if we combine absorption heat pump driven by waste heat with fuel cells, we can construct an advanced energy conserving system. The purpose of this study is the objective for evaluating the possibilities of effectively utilizing waste heat of fuel cells as a heat source for the single and double effect absorption systems. Simulation studies on single and double effect absorption have been performed for water/lithium-bromide pair. The effectiveness of introducing a waste heat source of fuel cells is demonstrated. The result of this study showed that total efficiency was about 85% at rated operation and about 75% at 75% load operation. Absorption cycle moved to more strong concentration when fuel cell operated at 75% load.

• 대한기계학회논문집B
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• 제32권9호
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• pp.669-675
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• 2008

The objectives of this paper are to examine the effect of nano-particles on the pool type absorption heat transfer enhancement and to find the optimal conditions to design a highly effective compact absorber for ammonia/water absorption system. The effect of $Al_2O_3$ nano-particles and carbon nanotube(CNT) on the absorption performance is studied experimentally. The experimental ranges of the key parameters are 20% of ammonia concentration, $0{\sim}0.08\;vol%$ (volume fraction) of CNT particles, and $0{\sim}0.06 \;vol%$ of $Al_2O_3$ nano-particles. For the ammonia/water nanofluids, the heat transfer rate and absorption rate with 0.02 vol% $Al_2O_3$ nano-particles were found to be 29% and 18% higher than those without nano-particles, respectively. It is recommended that the concentration of 0.02 vol% of $Al_2O_3$ nano-particles be the best candidate for ammonia/water absorption performance enhancement.

• 한국정보시스템학회지:정보시스템연구
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• 제23권1호
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• pp.139-159
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• 2014

Recently, theoretical interests in automatic uses, which can be activated without conscious intention, have been increased. According to previous studies, automatic uses are known to be determined by the strength of habit, the frequency of past uses, and emotional experiences such as cognitive absorption. Concerned on the influences of the above three factors on automatic uses, this paper suggested the following research questions: 'Which effect of cognitive absorption on automatic considering habit?' and 'Does the frequency of past uses always influence habit?'. In order to answer the research questions, this study suggested a research model which would explain the relationship among cognitive absorption, habit, and uses. Especially, cognitive absorption is formed as a moderating variable of the relationship between past use and habit, and the relationships among variables are longitudinally expanded. The suggested research model was empirically tested by surveying 175 'Facebook' users and analysed by partial least square (PLS), which showed the suggested hypotheses are significant. This results answered the research questions as followed: First, cognitive absorption moderates the relationship between habit and automatic use. Second, the frequency of past uses would not always influence the formulation of habit rather but may be influenced by habit.

• Preventive Nutrition and Food Science
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• 제8권1호
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• pp.1-6
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• 2003

Catechins exhibit a hypocholesterolemic effect in cholesterol-fed animals. The present study was conducted to examine whether (+)-catechin influences the absorption of cholesterol in rats. Male Sprague-Dawley rats were fed ad libitum an AIN-93G diet containing soybean oil for 5 wk. Rats with lymph cannulae were infused at 3.0 mL/h for 8 h via a duodenal catheter with a lipid emulsion containing radiolabeled cholesterol with or without (+)-catechin. Lymph was collected hourly for 8 h. The enteral infusion of (+)-catechin significantly lowered the lymphatic absorption of $^{14}$ C-cholesterol (21.1 $\pm$ 3.6% dose/B h) compared with controls infused with the lipid emulsion devoid of (+)-catechin (38.2 $\pm$ 1.2% dose/8 h). The intestinal absorption of $\alpha$-tocopherol (24.2$\pm$3.0% dose/8 h) also was significantly decreased by (+)-catechin infusion, relative to controls (32.2$\pm$2.2% dose/8 h). However, the lymphatic outputs of oleic acid and phospholipid were not affected by enteral (+)-catechin infusion. The results indicate that (+)-catechin has a profound inhibitory effect on the intestinal absorption of cholesterol and $\alpha$-tocopherol without affecting the absorption of fat.

• 한국가스학회지
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• 제3권1호
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• pp.14-20
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• 1999

[ $H_2O/LiBr$ ]계 흡수식 사이클에 압축기를 조합한 흡수압축사이클을 도입하여 증기를 단열압축시켜 그 증기의 응축열을 재생열로 이용하는 사이클에 대해서 시뮬레이션을 통하여 횹수압축사이클의 특성을 밝힌 연구이다. 기존의 흡수사이클에 압축기를 도입함에 따라 고효율 사이클을 실현할 수 있음을 제시하였으며, 흡수$\cdot$압축사이클의 구체적인 가능성을 제시하였다. 재생기에서 발생한 냉매증기를 단열압축시킨 TYPE 2는 단열압축 증기의 응축열만으로는 재생이 어려우므로 외부로부터 별도의 열량을 투입해야 하며 투입하는 외부열량에 폐열이나 2차 에너지를 이용할 수 있다면 높은 COP를 얻을 수 있어 실현가능성이 높다.

• Journal of Nutrition and Health
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• 제23권6호
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• pp.427-433
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• 1990

식이내 상이한 수준의 펙틴이 비타민 B$_{12}$의 흡수에 미치는 영향을 조사하였다. 무섬유식이를 섭취해온 흰쥐를 비타민 B$_{12}$흡수 정도를 측정하려는 전날, 무섬유, 2% 펙틴, 5% 펙틴, 그리고 10% 펙틴 식이군으로 나누었다. 다음날, 동물이 각기 배정된 식이를 섭취하는 동안, 57-Co-비타민 B$_{12}$를 구강으로 섭취시켜 그 흡수 정도를 측정하였다. 무섬유 식이와 비교하여 볼 때, 5%와 10% 펙틴 식이는 비타민 B$_{12}$의 흡수를 유의적으로 감소시켰다. 펙틴의 섭취량은 비타민 B$_{12}$의 흡수와 역상관 관계를 나타내었다.

• 전자공학회논문지D
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• 제35D권8호
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• pp.44-52
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• 1998

The theoretical modeling of transition energy and absorption coefficient for intersubband transitions in quantum wells in presented. We include, as well as hartree and exchange-correlation potentials, boht depolarization effect and exciton-like effect which play great roles in heavily doped cases where practically reasonable absorption coefficients are available. Also, the calculated results are compared with the existing experimental values for .delta.-doped Si quantum wells to check the validity of our theoretical calculation.

• 태양에너지
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• 제9권3호
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• pp.73-80
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• 1989

This paper presents as assessment based on steady-state thermodynamic analysis and computer modeling of a double effect generation absorption heating cycle for solar air-conditioning to find operating temperature ranges. The influences of component temperatures on the heating coefficients of performance and mass flow ratio have been investigated to obtain optimum operating conditions for the proposed air conditioning system. And the single and double effect absorption cycles are compared with each other over the same range of temperatures.