• 대한수의학회지
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• 제29권2호
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• pp.11-18
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• 1989

This study was undertaken to obtain basic data of the sternal development in Korean native cattle from the earliest sternal formation to the ossification using histological and histochemical methods. Thrity three sterna were collected from a series of embryos and fetuses ranging from 11 to 225mm (estimated age 37~120days) in crown rump length. The bilateral sternal bars were observed in the 2nd group(CRL 21~3mm) of Korean cattle embryos. Those bars initiated to be fused in the 3rd group (CRL 31~4mm) and completed in the 7th group(CRL 71~80mm). The ossification centers were detected in the 8th group(CRL 81~90mm) also bilateral ossification centers were found in the same group. The typical epiphyseal plates, endochondral bone and calcium deposit were found in the 9th group(CRL 91~100mm). Osteocytes, osteoblasts, osteoclasts and myeloid cells appeared in ossification centers in the 10th group(more than CRL 101mm). The alcianophility responded markedly in the 9th group that was decreased and showed slightly positive reaction in territorial matrix of the 10th group. Marked positive reaction to PAS was observed in bony trabeculae in the 10th group. The positive reaction to calcium deposit by trichrome stain was observed initially in the hypertrophied zone of epiphyseal plate in the 9th group and was conspicuous in the calcified zone of epiphyseal plate in the 10th group. The 1st positive reaction to the von Kossa stain was observed in the 9th group.

• 한방안이비인후피부과학회지
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• 제23권2호
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• pp.1-12
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• 2010

Objective : For this study, mice on mercurial toxication were given mercuric subcutaneous injection to their abdomen factitiously. After delivering Kami- bangpungtongseong-san(KBT) extracts to the mice by oral administration, we observed changes from liver and kidney of mice. Method : The BALB/c mice were distributed into three groups: No treated group(Normal group), Mercuric chloride subcutaneous injection group(Control group), Kami-bangpungtongseong-san-treated group (Sample group). KBT Extracts were delivered orally in 7 days. We observed involution of liver, necrosis of liver and cell plate loss of liver, lipid peroxidation CYP1A1 expression. We observed involution of proximal convoluted tubules, hypertrophy of Bowman's capsule, periodic acid-Schiff(PAS)'s positive reaction of proximal convoluted tubules, heat shock protein(HSP)700's positive reaction in glomerulus. For the charting the results, image analysis was taken. The result of image analysis was verified significance by Sigmaplot 2000(P<0.05). Result : The mice' liver on mercurial toxication were relieved involution of liver, necrosis of liver, and cell plate loss of liver and also declined lipid peroxidation and CYP1A1 expression. The mice' kidney on mercurial toxication were relieved involution of proximal convoluted tubules, hypertrophy of Bowman's capsule and increasing PAS's positive reaction of proximal convoluted tubules. On the other hand it was declined HSP700's positive reaction in glomerulus. Conclusion : According to the result of study, we think that we can expect to the effect of KBT extracts' therapeutic action to tissue injuries of the mice' liver and kidney on acute mercurial toxication.

• 접착 및 계면
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• 제8권3호
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• pp.1-8
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• 2007

폴리우레탄 폼 소재에 평판형 플라즈마 전처리 방식을 적용시켜 접촉각 및 접착력을 향상시켰다. 플라즈마 반응기의 최적의 반응조건을 조사하기 위해서 반응가스(질소, 아르곤, 산소, 공기), 가스의 유량(30~150 mL/min), 그리고 반응시간(0~30초) 등을 변화시켜 전처리하여 진공식 플라즈마 방식과 비교 검토하였다. 처리 후 소재의 표면 변화는 SEM과 ATR-FTIR을 이용하여 측정하였다. 폴리우레탄 폼에서 질소의 유량이 100 mL/min이고 반응시간이 10초일 때 접촉각의 저하에 따른 가장 좋은 접착력의 결과를 보여 주었다. 결과적으로 평판형 플라즈마 조작 방식에 의한 처리로 폴리우레탄 폼의 접촉각과 접착박리강도가 개선되었음을 확인하였다.

• 한국응용과학기술학회지
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• 제35권3호
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• pp.612-621
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• 2018

본 연구에서는 전기분해 방법을 이용한 질산성질소($NO_3{^-}-N$) 분해가 $TiO_2$ nanotube plate 및 구리, 니켈, 스테인리스 스틸, 알루미늄, 주석, 티타늄을 환원전극으로 사용하였을 때 가능한지를 평가하였다. 전극의 전기화학적 특성 평가는 임피던스 측정을 하여 비교하였고, $TiO_2$ nanotube plate의 표면 분석은 주사전자현미경을 통해 SEM 및 BET 분석법을 이용한 비표면적 분석을 통해 비교하였다. 질산성질소 전해실험의 경우 90분의 실험을 진행하였으며, 실험 결과 전극 표면의 부식이 수반되지 않은 $TiO_2$ nanotube plate가 기타 금속 전극에 비해 질산성질소 환원 반응속도가 가장 뛰어난 것으로 확인되었다.

• 한국전기전자재료학회논문지
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• 제26권4호
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• pp.289-293
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• 2013

We have studied structural, optical, and electrical properties of the Ga-doped ZnO (GZO) thin films being usable in transparent conducting oxides. The GZO thin films were deposited on the corning 1737 glass plate by the RF magnetron sputtering system. To find optimal properties of GZO for transparent conducting oxides, the Ar gas in sputtering process was varied as 40, 60, 80 and 100 sccm, respectively. As reaction gas decreased, the crystallinity of GZO thin film was increased, the optical bandgap of GZO thin film increased. The transmittance of the film was over 80% in the visible light range regardless of the changes in reaction gas. The measurement of Hall effect characterizes the whole thin film as n-type, and the electrical property was improved with decreasing reaction gas. The structural, optical, and electrical properties of the GZO thin films were affected by Ga dopant content in GZO thin film.

• 한국수산과학회지
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• 제19권3호
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• pp.212-218
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• 1986

In order to isolate antioxigenic substrates, the browning reaction products of xylose and various amino acids were analysed by TLC and dialysis. Rf values of browning reaction products of xylose and hydrophobic amino acids separated on silica gel TLC plate were shown in the range of 0.38 to 0.56 and that of basic amino acids was around 0.2. Browning reaction products made from xylose and Trp were separated on TLC into four bands with Rf values of 0.25, 0.55, 0.81 and 0.91 respectively. Among these the bands with Rf values of 0.25 and 0.55 appeared having strong antioxidant activity. The band of Rf 0.55 which showed the highest activity was positive to Prochazka reagent and had an absorption maximum at 275 nm. In dialysis of the xylose-Trp browning reaction products, the undialysed fraction (inner solution) was repsponsible to the antioxidant activity, which was separated into two bands with Rf values of 0.25 and 0.55 on TLC. The inner fractions of the browning products of xylose and His or Arg were also apparent in antioxdant activity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.101-104
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• 2007

금속 분리판으로 제작된 연료전지 스택의 기계적인 거동을 유한요소 해석을 통하여 살펴보았다. 연료전지의 구성요소는 크게 금속 분리판, 가스켓, MEA, GDL, 엔드 플레이트로 나눌 수 있다. 각각의 요소들은 적절한 힘에 의하여 체결되어야 하고 이에 의해 연료전지 스택의 성능이 많아 좌우된다. 유한 요소해석을 위해 가스켓, GDL을 금속 분리판 위에서 변위에 따른 힘의 변화를 실험을 통해 구했으며, 금속 분리판의 유로 부분을 단순 평판으로 치환하여 유한 요소해석을 진행하였고, 해석 결과와 실험결과가 일치함을 확인하였다. 이를 통해 금속 분리판 스택이 체결되었을 때의 기계적 거동을 유추할 수 있다.

• 한국수소및신에너지학회논문집
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• 제31권1호
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• pp.49-56
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• 2020

Epoxy/carbon composite was used to prepare a bipolar plate for polymer electrolyte membrane fuel cell (PEMFC). Phenol novolac-type epoxy and diglycidyl ether of bisphenol A (DGEBA)-type epoxy mixture was used as a matrix and graphite powder, carbon fiber (CF) and graphite fiber (GF) were used as carbon materials. In order to improve the mechanical properties of the bipolar plate, surface-modified CF was incorporated into the epoxy/carbon composite. To determine the cure temperature of the epoxy mixture, differential scanning calorimetry (DSC) analysis was performed and the data were introduced to Kissinger equation in order to get reaction activation energy and pre-exponential factor. Tensile and flexural strength was obtained by using universal testing machine (UTM). The surface morphology of the fractured specimen and the interfacial morphology between epoxy matrix and CF or GF were observed by a scanning electron microscopy (SEM).

• Journal of Mechanical Science and Technology
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• 제15권7호
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• pp.906-920
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• 2001

This paper presents three-dimensional mean velocities, turbulent intensities and Reynolds shear stresses measured in the Y-Z plane of the gas swirl burner with a cone type baffle plate by using an X-type hot-wire probe. This experiments is carried out at the flow rate of 450ℓ/min which is equivalent to the combustion air flow rate necessary to heat release 15,000 kcal/hr in a gas furnace. Mean velocities and turbulent intensities etc. show that their maximum values exist around the narrow slits situated radially on the edge of and in front of a burner. According to downstream regions, they have a peculiar shape like a starfish because the flows going out of the narrow slits and the swirl vanes of an inclined baffle plate diffuse and develop into inward and outward of a burner. The rotational flow due to the inclined flow velocity going out of swirl vanes of a cone type baffle plate seems to decrease the magnitudes of mean velocities V and W respectively by about 30% smaller than those of mean velocity U. The turbulent intensities have large values of 50%∼210% within the range of 0.5

• 한국수소및신에너지학회논문집
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• 제18권1호
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• pp.40-45
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• 2007

Methylene blue(MB) was photocatalytically degraded with one-body photoanode and solar simulator to investigate the possible application to both environmental purification and photoelectrochemical cell for hydrogen production. Photoactive titanium dioxide was formed on both sides of Ti plate following steps such as rinsing-annealing-calcination or anodizing(20 V, 30 V)-annealing($350^{\circ}C$, $450^{\circ}C)$ after etching. The prepared titania plate($2cm{\times}2\;cm$, ca 1.6 mg $TiO_2$ on the basis of $1\;{\mu}m$ thickness) was used to degrade MB(10 ppm in 200 mL solution). The reaction tended to follow the Langmuir-Hinshelwood kinetics with zero order. Comparative experiments with Degussa P25 showed the same zero order kinetics when 2 mg of P25 had been used, while the first order kinetics when 200 mg used. This concludes the feasibility of the prepared titania plate as a material for the purification of low-level harmful organics and an electrode or a membrane for photoelectrochemical system for hydrogen production.