• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 춘계 학술대회논문집
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• pp.91-95
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• 2005

A heat dissipation modeling method of EEE parts is developed for thermal design and analysis of an satellite electronic equipment. The power consumption measurement value of each functional breadboard is used for the heat dissipation modeling method. For the purpose of conduction heat transfer modeling of EEE parts, surface heat model using very thin ignorable thermal plates is developed instead of conventional lumped capacity nodes. The thermal plates are projected to the printed circuit board and can be modeled and modified easily by numerically preprocessing programs according to design changes. These modeling methods are applied to the thermal design and analysis of CTU and verified by thermal cycling and vacuum tests.

• Elastomers and Composites
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• 제54권3호
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• pp.201-208
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• 2019

Superabsorbent hydrogel (SAH) is a lightly crosslinked hydrophilic functional polymer material comprising a flexible chain structure, which can absorb and retain high amounts of water or aqueous fluids even under high pressure. Therefore, it is important to improve their characteristics such as absorption performance, residual monomer content, and water permeability. SAH nanocomposites were prepared using clay mineral as an inorganic filler and the influence of post-treatment processes such as quenching and aging process on their properties was studied. In addition, surface-crosslinking process was applied to improve the absorption performance associated with mechanical properties and water permeability. The structure of the SAH was characterized using attenuated total reflectance Fourier transform infrared spectroscopy, X-ray diffraction analysis, and scanning electron microscopy.

• 한국산학기술학회논문지
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• 제14권10호
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• pp.4747-4752
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• 2013

MR 유체의 물리적 특성은 자기장에 의해 영향을 받으며, 베이스 오일에 마이크로 크기의 자성 파우더가 분산되어 있다. 그러므로 오일과 파우더의 밀도 차이로 MR 댐퍼에 사용되는 MR 유체의 분산 안정성은 중요한 문제이다. 본 실험연구에서는 MR 댐퍼에 사용되는 MR 유체의 화학적 조성에 따른 물리적 특성을 규명해보고자 MR 유체를 제조하여 분산 안정성과 물리적 특성을 조사하였다. 216종의 MR 유체는 자성파우더(2종), 계면활성제(2종), 베이스오일(2종), 특성첨가제(3종), 밀도(3종), 점도(3종)을 이용하여 제조되었다. 실험결과로부터 SEM, 자속밀도, MR 유체의 상등액과 침강층의 분산 자료를 확보하였다.

• Journal of Animal Science and Technology
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• 제65권3호
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• pp.652-663
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• 2023

The rumen fluids contain a wide range of bacteria, protozoa, fungi, and viruses. The various ruminal microorganisms in the rumen provide nutrients by fermenting the forage they eat. During metabolic processes, microorganisms present in the rumen release diverse vesicles during the fermentation process. Therefore, in this study, we confirmed the function of rumen extracellular vesicles (EVs) and their interaction with the host. We confirmed the structure of the rumen EVs by transmission electron microscope (TEM) and the size of the particles using nanoparticle tracking analysis (NTA). Rumen EVs range in size from 100 nm to 400 nm and are composed of microvesicles, microparticles, and ectosomes. Using the Caenorhabditis elegans smart animal model, we verified the interaction between the host and rumen EVs. Exposure of C. elegans to rumen EVs did not significantly enhance longevity, whereas exposure to the pathogenic bacteria Escherichia coli O157:H7 and Staphylococcus aureus significantly increased lifespan. Furthermore, transcriptome analysis showed gene expression alterations in C. elegans exposed to rumen EVs, with significant changes in the metabolic pathway, fatty acid degradation, and biosynthesis of cofactors. Our study describes the effect of rumen EV interactions with the host and provides novel insights for discovering biotherapeutic agents in the animal industry.

• Journal of Trauma and Injury
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• 제35권3호
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• pp.209-214
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• 2022

We describe a case of hyperbaric oxygen therapy (HBOt) as an adjunct to treatment of a crush injury to the hand. A 34-year-old male paramedic was involved in a motor vehicle accident and admitted for diagnosis and surgical treatment. He sustained a crush injury to his right hand and presented with significant muscle damage, including multiple fractures and dislocations, an avulsion injury of the flexor tendons, and amputation of the distal phalanx of the little finger. He underwent reconstructive surgery and received HBOt over the following days. In the following 2 months, he lost the distal and middle phalanges of the little finger and recovered hand function. Posttraumatic compartment syndrome responds well to HBOt, which reduces edema and contributes to angiogenesis, as well as promoting the cascade of healing events. High-energy trauma causes massive cell destruction, and the blood supply is usually not sufficient to meet the oxygen demands of viable tissues. Hyperbaric oxygenation by diffusion through interstitial and cellular fluids increases tissue oxygenation to levels sufficient for the host's responses to injury to work and helps control the delayed inflammatory reaction. HBOt used as an adjunct to surgical treatment resulted in early healing and rehabilitation, accelerating functional recovery. The results suggest that adjunctive HBOt can be beneficial for the treatment of crush injuries of the hand, resulting in better functional outcomes and helping to avoid unnecessary amputations.

• 한국정밀공학회지
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• 제25권10호
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• pp.48-57
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• 2008

MR Fluid, one of functional fluids, is developed for the application to automobile products. MR CDC damper using MR fluid has following principles. When ar electric current is applied to the solenoid, apparent viscosity of MR fluid passing through the annular gap which acts as magnetic circuits varies directly as the intensity of the current. These devices have a simple structure and excellent lime response characteristics, emerging as the alternatives of the conventional semi-active suspension systems. In this study, a design procedure of the magnetic circuit through the solenoid fore and the flux ring functioning as a magnetic path is investigated so as to optimize the design and performance of MR CDC dampers for the vehicles. In addition, an operating point on the B-H curve, the magnetization according to the variation in the annular gap, the pole piece width and the density of MR fluid are studied to design the optimal piston head within the restrained dimension range.

• 생약학회지
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• 제51권1호
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• pp.1-29
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• 2020

Diabetes mellitus, commonly known as diabetes, is a group of metabolic disorders characterized by high blood sugar levels over a prolonged period. Diabetes has been found to show many acute complications such as cardiovascular disease, stroke, chronic kidney disease, foot ulcer and damage to eyes. Korean ginseng (Panax ginseng) has been traditionally known to normalize the functional deficiencies of the lung, spleen and stomach, and thus improve the secretion of body fluids, thereby quenching thirst, suggesting it to be effective in the treatment of diabetes. Experimental studies (in vitro and in vivo) have recently shown that Korean ginseng and its extracts exhibit antidiabetic effects, and also insulin secretion and sensitizing effects related to blood glucose control. Moreover, clinical trials on antidiabetic effects of Korean ginseng have been reported to show blood glucose control, improvement of insulin resistance, reduction of postprandial blood glucose level and improvement of serum lipids (TG, TC, LDL-C). These will be critically examined by means of in vitro studies, cell experiment, animal models and human trials with a focus on understanding of molecular mechanisms.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.269-274
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• 1995

For the screening of a new functional exopolysaccharide, sugar composition and rheological properties of exopolysaccharide produced from Xanthomonas sp. EPS-1 were investigated. The average molecular weight of exopolysaccharide was determined to be approximately 2.l $\times$ 10$^{6}$ dalton. The new exopolysaccharide EPS-1 was composed of mannose, glucose, galactose and gluco- samine. IR analysis showed that the exopolysaccharide EPS-1 was assumed to be polymer with carbohydrates. NMR analysis showed that exopolysaccharide EPS-1 was presumed to be 4 units of sugar and trace of CH$_{3}$ group. Exopolysaccharide EPS-1 solution showed a characteristic of non-Newtonian fluid properties. At the concentration of 1.0%, the consistency index and the flow behavior index were shown at 10.8352 poise-sec and 0.4419, respectively. All dispersions were pseudoplastic fluids described accurately by Power-law model. Exopolysaccharide EPS-1 was highly viscous at low concentration, with good stability over a wide range of pH 5 to 13. The excellent compatibility of exopolysaccharide EPS-1 was represented with salts such as sodium chloride.

• 대한한의학원전학회지
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• 제23권1호
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• pp.1-10
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• 2010

Wi Syndrome(痿證) mainly occurs from fluid damages[津液損傷] caused by heat in Gi(氣) phase of the Five viscera, while it sometimes come from the outside. Although the symptoms are presented in the limbs, the disorder roots in the Five viscera, most deeply located in the human body, Therefore, to approach the disorder, we must apply differentiation of the Five viscera in diagnosis. The Lungs, as the head of the Five viscera control the production and distribution of bodily fluids in the body. Functional disorder of the Lungs bring about Wi Syndrome regardless of it being in the Gi phase. Also, psychological depression leads to Wi Syndrome, In other words, depression and uneasiness easily results in the state of Gi blocking and fluid exhaustion in this modern society where there is less manual labor and excessive use of the brain. Besides Gi blockage, the top muscle[宗筋] theory is another important mechanism in the occurrence of Wi Syndrome. Moreover, the disorder is related to Yangmyeong(陽明), which is the sea of food, Chungmaek(衝脈) which is the sea of meridian, in addition to Immaek(任脈), Dokmeak (督脈) and Deameak(帶脈) which are all involved in Wi Syndrome. In conclusion, the Wi Syndrome happens when various factors involved lose balance and harmony with each other.

• 한국해안해양공학회지
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• 제11권1호
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• pp.1-6
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• 1999

해안 및 해양에 설치되어 있는 해저관로는 원유, 가스, 물과 이들의 혼합된 유체들을 전달하기 위한 수단으로 사용되고 있다. 관로 내부 유체의 열과 압력 차이는 해저관로의 팽찰을 야기시킨다. 해전관로 팽창은 관로와 연결되는 구조물들에 응력을 유발시킨다. 작용 응력이 연결 부재의 항복점을 초과하거나 전체 시스템의 허용변형을 초과할 경우 구조물에 손상이 발생된다. 해안 및 해양에 설치되는 해저관로는 주로 위험 물질이나 유독 유체를 포함하기 때문에 만약 이런 유체의 유출이 발생될 경우 인명 피해는 물론 큰 경제적 손실을 가져온다. 비록 해저관로는 시간적/공간적 제약 없이 유체를 전달할 수 있지만, 이런 관로 설계시 안전하게 그 기능을 수행할 수 있도록 고려되어야 한다. 본 논문에서는 해저관로의 열변형 해석에 사용되는 여러 개의 이론을 조사하였고, 관로의 요소들이 관로 팽창에 미치는 영향에 대해 조사하였다.