• International Journal of Concrete Structures and Materials
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• 제10권2호
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• pp.249-256
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• 2016

This paper deals with the effects of silica fume content and polymer-binder ratio on the properties of ultrarapid-hardening polymer-modified mortar using silica fume and ethylene-vinyl acetate redispersible polymer powder instead of styrene-butadiene rubber latex to shorten the hardening time. The ultrarapid-hardening polymer-modified mortar was prepared with various silica fume contents and polymer-binder ratios, and tested flexural strength, compressive strength, water absorption, carbonation depth and chloride ion penetration depth. As results, the flexural, compressive and adhesion strengths of the ultrarapid-hardening polymer-modified mortar tended to increase as increasing polymer-binder ratio, and reached the maximums at 4 % of silica fume content. The water absorption, carbonation and chloride ion penetration resistance were improved according to silica fume content and polymer-binder ratio.

• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.279-283
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• 1992

Eighteen wether lambs averaging 32 kg were used to determine the effects of dietary silica, added as silicic acid, on mineral metabolism. Lambs were fed 1200 g daily of a coastal Bermuda grass based diet supplemented with either 0, .5 or 1.5% silicic acid. A 7-d total collection of urine and feces was conducted after lambs had adjusted to the dietary treatments for 19 days. Urinary excretion of silica was higher (p<.01) in lambs fed added silicic acid. Ruminal soluble concentrations of manganese tended to be lower (p<.10) and apparent absorption and retention of manganese were lower (p<.05) in lambs supplemented with silicic acid compared to control lambs. Apparent absorption and retention of calcium were slightly lower (p<.10) in silicic acid fed lambs. No differences in urinary between lambs fed .5 and those given 1.5% silicic acid. Phosphorus, magnesium, iron, zinc and copper absorption and retention were not affected by treatment.

• 한국자동차공학회논문집
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• 제6권3호
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• pp.177-186
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• 1998

For the purpose of finding out the sound field characteristics in a cavity of a rectangular enclosure with foamed aluminum lining, analytical and experimental studies are performed with random noise input. Experimental method using two-microphone impedance tube measures the absorption coefficients and the impedances of simple sound absorbing materials. Measured acoustical parameters of the test samples are applied to the theoretical analysis to predict sound pressure field in the cavity. The sound absorp- tion effects from measurements are compared to prediction in both cases with and without foamed aluminum lining in the cavity of the rectangular enclosure.

• Nutrition Research and Practice
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• 제3권1호
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• pp.9-14
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• 2009

Aloe products are one of the top selling health-functional foods in Korea, however the adequate level of intake to achieve desirable effects are not well understood. The objective of this study was to determine the intestinal uptake and metabolism of physiologically active aloe components using in vitro intestinal absorption model. The Caco-2 cell monolayer and the everted gut sac were incubated with $5-50{\mu}M$ of aloin, aloe-emodin, and aloesin. The basolateral appearance of test compounds and their glucuronosyl or sulfated forms were quantified using HPLC. The % absorption of aloin, aloe-emodin, and aloesin was ranged from 5.51% to 6.60%, 6.60% to 11.32%, and 7.61% to 13.64%, respectively. Up to 18.15%, 18.18%, and 38.86% of aloin, aloe-emodin, and aloesin, respectively, was absorbed as glucuronidated or sulfated form. These results suggest that a significant amount is transformed during absorption. The absorption rate of test compounds except aloesin was similar in two models; more aloesin was absorbed in the everted gut sac than in the Caco-2 monolayer. These results provide information to establish adequate intake level of aloe supplements to maintain effective plasma level.

• 한국산업보건학회지
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• 제30권2호
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• pp.226-235
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• 2020

Objectives: This study was to investigate the signs and notations of skin absorption, carcinogenicity, germ cell mutagenicity, and reproductive toxicity in the occupational exposure limits of Korea and of other advanced countries. Methods: Information on occupational exposure limits in Korea, the USA, the UK, Germany, and Japan was investigated through the Internet, and items marked as carcinogenicity and skin absorption were compared by country. Results: Legal occupational exposure limits have been greatly simplified. However, in the case of HSE WEL, skin absorption, carcinogenicity classification, sensitization, and in the case of DFG MAK, skin absorption, carcinogenicity, pregnancy risk group, germ cell mutagenicity, airway and skin sensitization, photo contact sensitization, and vapor pressure were provided. Conclusions: It is desirable to indicate the carcinogenicity and skin absorption within permissible limits, and to include information on critical effects in chemical substance exposure limits to uphold the right to know of industrial hygienists and workers in Korea. It is also necessary to clarify the precautions, limitations and protections for skin absorption.

• Steel and Composite Structures
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• 제21권3호
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• pp.605-628
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• 2016

The energy absorption characteristics of diamond core sandwich cylindrical columns under axial crushing process depend greatly on the amount of material which participates in the plastic deformation. Both the single-objective and multi-objective optimizations are performed for columns under axial crushing load with core thickness and helix pitch of the honeycomb core as design variables. Models are optimized by multi-objective particle swarm optimization (MOPSO) algorithm to achieve maximum specific energy absorption (SEA) capacity and minimum peak crushing force (PCF). Results show that optimization improves the energy absorption characteristics with constrained and unconstrained peak crashing load. Also, it is concluded that the aluminum tube has a better energy absorption capability rather than steel tube at a certain peak crushing force. The results justify that the interaction effects between the honeycomb and column walls greatly improve the energy absorption efficiency. A ranking technique for order preference (TOPSIS) is then used to sort the non-dominated solutions by the preference of decision makers. That is, a multi-criteria decision which consists of MOPSO and TOPSIS is presented to find out a compromise solution for decision makers. Furthermore, local and global sensitivity analyses are performed to assess the effect of design variable values on the SEA and PCF functions in design domain. Based on the sensitivity analysis results, it is concluded that for both models, the helix pitch of the honeycomb core has greater effect on the sensitivity of SEA, while, the core thickness has greater effect on the sensitivity of PCF.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.19-26
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• 2007

This paper concerns the study of absorption refrigeration and heat pump cycle to use sewage. Simulation analysis on the double-effect absorption refrigeration cycle with parallel and two-stage heat pump cycle has been performed. The working fluid is Lithium Bromide and water solution. The absorption refrigeration cycle use sewage as a cooling water for the absorber and condenser, and absorption refrigeration cycle does that as a chilled water for the evaporator of the first stage cycle. And the two-stage cycle consists of coupling double-effect with parallel and single effect cycle so that the first stage absorber and condenser produces heating water to evaporate refrigerant in the evaporator of the second stage. The effects of operating variables such as a absorber temperature on the coefficient of performance have been studied for absorption refrigeration and heat pump cycle.

• 한국운동역학회지
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• 제24권1호
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• pp.59-66
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• 2014

The purpose of this study was to investigate the effects of knee joint muscle fatigue and overweight on shock absorption during single-leg landing of adult women. Written informed consent forms, which were approved by the human subject research and review committee at Dong-A University, were provided to all subjects. The subjects who participated in this study were divided into 2 groups: a normal weight group and an overweight group, consisting of 15 young women each. Both the normal weight group and the overweight group showed that use soft landing and ankle dominant strategy. The peak vertical ground reaction force, the knee joint absorption power, and eccentric work done, as the increase of knee joint muscle fatigue level, showed a decrease. And the hip joint absorption power and eccentric work done, as the increase of weight, was less than the overweight group showed the normal weight group. In conclusion, the accumulation of the knee joint muscle fatigue and the increase of body weight may lead to an increased risk of injury during landing.

• 설비공학논문집
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• 제17권9호
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• pp.830-838
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• 2005

The present study investigated the optimization of the absorption performance of the vertical absorber tube with falling film by considering heat and mass transfer simultaneously. Effects of film Reynolds number, geometric parameters by insert device (spring) and flow pattern on heat and mass transfer performances have been also investigated. Especially, effects of coolant flow rate and the flow pattern by geometric parameters has been observed for the total heat and mass transfer rates through both numerical and experimental studies. Based on both predicted values, the optimal coolant flow rate was predicted as 1.98 L/min. The maximum absorption rate of the spring inserted tube was increased by the maximum of $20.0\%$ than those for uniform film of bare tube. Average Sherwood numbers and Nusselt numbers were increased as Reynolds numbers increased under the dynamic and geometric conditions showing the maximum absorption performance.

• 대한안전경영과학회지
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• 제20권4호
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• pp.21-37
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• 2018

The purpose of this research was to test the effects of entrepreneurship and technological innovation capability on new product performance in SMEs and the moderating role of absorption capability. For this study, Research data were collected through questionnaire instruments from the sample of 374 employees in 18 SMEs of metropolitan area. The 336 sample was selected and analyzed by hierarchical regression technique. The results showed that entrepreneurship and technological innovation capability had a positive effect on new product performance. And also found out absorption capability had the moderate roles between all the three factors of technological innovation capability factors and new product performance, but not between all the three factors of entrepreneurship and new product performance. With the research results, the implications for technical management of SMEs were discussed, and the directions for future research were suggested.