• 한국초지조사료학회지
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• 제16권4호
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• pp.267-274
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• 1996

This experiment was carried out to investigate the effect of pasture types(mixture and mono tall fescue pasture) and endophyte infection on the animal behavior of Korean native cattle at the Experimental Field of Grassland and Forage Crops Division, National Livestock Research Institute, Suweon, in 1994. The results obtained are sumunarized as follows: DM intake of Korean native cattle was increased with mixture and endophyte-free tall fescue for both pasture types. Mixture and endophyte-free tall fescue showed good animal preference. Daily grazing time was increased with mixture and endophyte-free tall fescue in monoculture, while annual grazing period was increased with monoculture and endophyte-infect tall fescue. Amount of drinking water of Korean native cattle was increased with tall fescue monoculture rather than mixture, however the amount of drinking water was higher with endophyte-infect tall fescue in monoculture. Salt intake of Korean native cattle was increased with mixture and endophyte-6ee tall fescue in monoculture. Rectal temperature of Korean native cattle was not influenced by pasture types and endophyte infection. Based on the results of this experiment, DM intake of Korean native cattle and daily grazing time were increased by mixture and endophyte-free tall fescue with good quality.

• 한국물환경학회지
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• 제30권2호
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• pp.220-225
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• 2014

A sequencing batch reactor (SBR) was operated to obtain thiosulfate-utilizing denitrifier cultivated with two types of electron accepter (nitrate and nitrite). Using the microbial biomass obtained from the SBR, batch tests were conducted with different nitrite concentrations (50 and 100 mg-N/L) at pH 7.0, 7.5 and 7.9 to see how free nitrous acid (FNA) negatively works on the thiosulfate-utilizing denitrification of nitrate. The specific denitrification rate (SDR) of nitrate was significantly influenced by pH and FNA. The presence of nitrite caused a remarked decrease of the SDR under low pH conditions, because of the microbiological inhibitory effect of FNA. The minimum SDR was observed when initial nitrite concentration was 100 mg-N/L at pH 7.0. Moreover. the SDR was influenced by the type of electron acceptor used during the SBR operation. Thiosulfate-utilizing denitrifier cultivated with nitrite showed smaller SDR on the thiosulfate-utilizing denitrification of nitrate than those cultivated with nitrate.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.163-166
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• 2016

Hydrophobicity is the key concept to understand the water plays in protein folding, protein aggregation, and protein-protein interaction. Traditionally, the hydrophobicity of protein is defined based on the scales of the hydrophobicity of residue, assuming that the hydrophobicity of free amino acids is maintained. Here, we explore how the hydrophobicity of constituting amino acids in protein rely on the protein context, in particular, on the total charge and secondary structures of a protein. To this end, we calculate and investigate the hydration free energy of three short proteins based on the integral-equation theory of liquids. We find that the hydration free energy of charged amino acids is significantly affected by the protein total charge and exhibits contrasting behavior depending on the protein total charge being positive or negative. We also observe that amino acids in the ${\beta}-sheets$ display more enhanced the hydrophobicity than amino acids in the loop, whereas those in the ${\alpha}-helix$ do not clearly show such a tendency. And the salt-bridge forming amino acids also exhibit increase of the hydrophobicity than that with no salt bridge. Our results provide novel insights into the hydrophobicity of amino acids, and will be valuable for rationalizing and predicting the strength of water-mediated interaction involved in the biological activity of proteins.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.884-893
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• 2019

Spent fuel racks are steel structures used in the storage of the spent fuel removed from the nuclear power reactor. Rack units are submerged in the depths of the spent fuel pool to keep the fuel cool. Their free-standing design isolates their bases from the pool floor reducing structural stresses in case of seismic event. However, these singular features complicate their seismic analysis which involves a transient dynamic response with geometrical nonlinearities and fluid-structure interactions. An accurate estimation of the response is essential to achieve a safe pool layout and a reliable structural design. An analysis methodology based on the hydrodynamic mass concept and implicit integration algorithms was developed ad-hoc, but some dispersion of results still remains. In order to validate the analysis methodology, vibration tests are carried out on a reduced scale mock-up of a 2-rack system. The two rack mockups are submerged in free-standing conditions inside a rigid pool tank loaded with fake fuel assemblies and subjected to accelerations on a unidirectional shaking table. This article compares the experimental data with the numerical outputs of a finite element model built in ANSYS Mechanical. The in-phase motion of both units is highlighted and the water coupling effect is detailed. Results show a good agreement validating the methodology.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.233-243
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• 2019

In this paper, numerical and experimental studies are performed to investigate the liquid impact on a free falling wedge. In the numerical simulation, the structure is assumed to be rigid and the elastic response is ignored. The fully nonlinear coupling between wedge and water is considered by an auxiliary function method based on the Boundary Element Method (BEM). At the intersection of the wedge surface and liquid surface, two coincident nodes are used to decouple the boundary conditions. The Eulerian free surface conditions in the local coordinate system are adopted to update the deformed free surface. In the experiments, five pressure sensors are fixed on each side of the wedge which is released from an experimental installation. Steel and aluminum wedges that have different structural elasticity are used in the experiments to investigate the influence of structural elasticity on the impact force. Numerical results are compared with experimental data and they agree very well. The influence of fluid gravity, body mass, initial entry speed and deadrise angle on the impact pressure are further investigated.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.466-477
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• 2021

There are three different well-known methods for predicting the manoeuvrability of ships: (1) free running model test, (2) direct manoeuvring simulation using CFD and (3) system-based manoeuvring simulation. In this paper, the manoeuvrability of the KVLCC2 was estimated using CFD with rigid body motion and body force propeller method. The free running manoeuvre at the different time steps were also simulated. The yaw checking ability and the turning ability of KVLCC2 were predicted using CFD and could have been confirmed that the IMO criteria was satisfied. When the results were compared with the model test and system-based method, the free running simulation showed better agreement to that of the model test. It could also be confirmed that the results vary depending on the time step. Overall, the CFD results using the body force propeller method estimated most accurately the test results.

• Journal of Nutrition and Health
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• 제40권5호
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• pp.428-434
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• 2007

본 연구에서는 무철분식이로 철분결핍성 빈혈 유발을 시킨 흰쥐에게 3주간 무철분식이를 섭취시키면서 saline, 참당귀 추출물 및 철분보충제를 투여한 후, 무철분식이를 일반식이로 대체하여 다시 3주간 같은 처리를 한 후 혈액학적 빈혈지표를 조사하여 결과를 요약하면 다음과 같다. 1) 실험동물의 체중은 무철분식이군에서 일반식이군에서 보다 유의적으로 낮게 나타났다. 무철분식이로 인한 저체중은 참당귀 추출물과 철분 보충제에 의해서 회복되지 않았다. 2) 혈액분석 결과 무철분식이는 모든 혈액 빈혈지표를 저하시켰으며, 철분보충제의 투여는 헤모글빈, 헤마토크릿, 평균 혈구 부피, 평균 혈구혈색소, 평균 혈구혈색소 농도, 총철결합능력이 유의적으로 회복시켰다. 무철분식이와 함께 투여한 참당귀 추출물은 혈액지표를 개선시키지 못하였다. 한편, 일반식이와 함께 섭취하였을 경우, 헤모글로빈, 헤마토크릿, 평균 혈구부피, 평균 혈구혈색소, 평균 혈구혈색소 농도, 총철결합능력 모두 유의적인 회복효과를 보였으나 일반식이만을 섭취한 군에서도 같은 회복효과를 보였다. 결론적으로, 장기간에 걸쳐 철분 섭취가 불량할 경우, 체중증가가 지연되며 후에 철분을 보충할 경우에도 체중의 회복은 개선되지 않았다. 철분결핍으로 인한 저체중의 경우, 철분보충제의 복용은 체중을 만회시키지 못하였으나 혈액학적 빈혈 지표들은 회복시키는 것으로 나타났다. 철분결핍 빈혈에서 식이철분이 부족할 경우, 참당귀의 회복효과는 미비한 것으로 나타났다. 향후 철분결핍 빈혈의 치료를 위한 생약제의 다양한 작용을 밝히기 위하여서는 영양학적인 관점에서 체내 이용률에 관한 심도 깊은 연구가 이루어져야 할 것으로 사료된다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2000년도 춘계학술대회
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• pp.6-7
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• 2000

Recently, free radicals such as active oxygen species, nitric oxide, etc are believed to be one of the key substances in physiological and pathological, toxicological phenomena, and oxidative damages, and all organism have defencing system against such as free radicals. Formation and extinction of free radicals may be regulated through bio-redox system, in which various enzymes and compounds should be involved in very complicated manner. Thus, direct and non-invasive measurement of in vivo free radical reactions with living animals must be essential to understand the role of free radicals in pathophysiological phenomena. Electron spin resonance spectroscopy (ESR) is very selective and sensitive technique to detect free radicals, but a conventional ESR spectrometer has large detect in application to living animals, since high frequent microwave is absorbed with water, resulting in generation of high fever in living body. In order to estimate in vivo free radical reactions in living whole animals, we develop in vivo ESR-CT technique using nitroxide radicals as spin probes. Nitroxide radicals and their reduced forms, hydroxylamines, are known to interact with various redox systems. We found that! ! the signal decay due to reduction of nitroxyl radicals is influenced by aging, inspired oxygen concentration, ischemia-referfusion injury, radiation, etc. In the present paper, I will introduce in vivo ESR technique and my laboratory recent results concerning non-invasive evaluation of free radical reactions in living mice.

• 동력기계공학회지
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• 제18권3호
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• pp.73-78
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• 2014

Recently, Free cooling system usage has increased at many buildings in intermediate and winter season. Free cooling system is used to reduce the energy consumption of refrigeration in that season. Free cooling system is refrigeration system using cooled water. In general, this system is applied with the building having refrigeration load at all time such as a data center. In this study, energy consumption of a data center taking free cooling system in Ulsan was evaluated by the software HYSYS. the main result is as in the following : free cooling system is effective from January to April and from November to December. In case of Ulsna in 2013, using free coolng system is able to spend refrigeration energy of about 15% less than existing system. According to this result, it is appropriated that free cooling system is used in building having refrigeration load at all time such as data center.

• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.8-11
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• 1999

The optimum boiling condition was determined for fish extracts by response surface model. Model equations were designed with effect of time (T) and the amount of added water (W) on the level of released free amino acid. Based on the high (>0.9) coefficient of determination and low (<0.01) level of significant, those model was approved to be significant. The added water amount of higher regression coefficient $ (\beta_2)$, showed a greater influence on releasing free amino acids than boiling time. The optimum boiling times are 6 hours for crucian carp, 5 hours for bastard halibut, 7 hours for loach and 5 hours for jacopever. The ratio of added water to sample 1 (v/w) could be applied to all fish samples at $100\pm2^{\circ}C$.