• Asian-Australasian Journal of Animal Sciences
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• 제12권5호
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• pp.752-757
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• 1999

Studies were made of digestion of timothy (Pheleum pretense) hay, tall fescue (Festuca elatior) hay, and rice (Oryza sativa) straw in pure cultures of rumen anaerobic fungus, Neocallimastix frontails MCH3. The fungus was inoculated on ground forages (1%, w/v) in an anaerobic medium and incubated at $39^{\circ}C$. Incubation was continued for 24, 48, 72 and 96 h. The losses of dry matter, xylose and glucose of forage during incubation were determined at the end of these incubation periods. Xylose and glucose were considered to be released from xylan and cellulose, respectively. The digested xylan to digested cellulose (X/C) ratios of the substrate were calculated. Xylanase and carboxymethyl cellulose (CMCase) of culture supernatant and residual substrate was measured at the same time. The X/C ratios in the cultures on timothy hay and rice straw were greater than 0.5 in the first 24-h incubation period. The values were smaller than 0.3 in tall fesque. The ratio of xylanase activity to that of CMCase in the first 24-h incubation period correlated well with the traits in X/C ratio. However xylanase activity was still superior to CMCase in the following incubation period (48 to 96 h), although the glucose (designated as cellulose) was more intensively digested than xylose (designated as xylan). The production of these polysaccharidases appeared to correlate with substrate cell-wall sugar composition, xylose to glucose ratios, at the beginning of fast growing period.

• 전산구조공학
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• 제8권4호
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• pp.159-171
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• 1995

한 cycle의 이력곡선 loop을 완전히 표현하기 위해서는 pinch force, drift offset, effective stiffness, unloading, reloading, tangential stiffness 등의 변수가 필요하게 된다. 각 이력 loop에 대해 이들 변수들은 에너지 소산정도에 따라 변위와 축력의 함수로 표현될 수 있다. 본 논문에서는 먼저 16개의 전단벽 실험에서 얻어진 이력곡선 데이타를 분석하여 앞에 기술된 모든 변수를 표준화된 변위(.DELTA/.DELTA.y)의 함수로 표현했으며 이를 바탕으로 이력곡선의 포락선으로 표현되는 힘-변위관계를 예측할 수 있는 6개의 step을 제시하였다. 제시된 기법으로 구해진 비탄성 힘-변위관계는 실험곡선과 비교되었으며 내진설계에 있어서 가장 중요한 요소중 하나인 구조물의 비탄성 힘-변위관계를 예측하는 편리한 기법으로 이용될 수 있음을 보였다.

• The Plant Pathology Journal
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• 제33권3호
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• pp.238-248
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• 2017

Pokkah Boeng is a serious disease of sugarcane, which can lead to devastating yield losses in crop-producing regions, including southern China. However, there is still uncertainty about the causal agent of the disease. Our aim was to isolate and characterize the pathogen through morphological, physiological, and molecular analyses. We isolated sugarcane-colonizing fungi in Fujian, China. Isolated fungi were first assessed for their cell wall degrading enzyme capabilities, and five isolates were identified for further analysis. Internal transcribed spacer sequencing revealed that these five strains are Fusarium, Alternaria, Phoma, Phomopsis, and Epicoccum. The Fusarium isolate was further identified as F. verticillioides after Calmodulin and EF-$1{\alpha}$ gene sequencing and microscopic morphology study. Pathogenicity assay confirmed that F. verticillioides was directly responsible for disease on sugarcane. Co-inoculation of F. verticillioides with other isolated fungi did not lead to a significant difference in disease severity, refuting the idea that other cellulolytic fungi can increase disease severity as an endophyte. This is the first report characterizing pathogenic F. verticillioides on sugarcane in southern China.

• Journal of Chest Surgery
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• 제16권2호
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• pp.175-183
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• 1983

Ventricular aneurysm which was first described by John Hunter on 18th century, has been experienced by many surgeons after successful using of cardiopulmonary bypass by Cooley on 1958. According to Gorlin, the definition of ventricular aneyrysm is portion of the ventricle which is not motile at systole (akinesis) or which has paradoxical dilatation at systole(dyskinesis). The ventricular aneurysm is classified to anatomical and functional. The anatomical ventricular aneurysm is devided into true or false again. Average age incidence is ranged from 49 to 60 and male predominance is reported. The cause is ischemic coronary artery disease in almost cases but hypertropoc cardiomyopathy, congenital abscence of myocardium, complication after mitral valvular replacement and trauma may also cause the ventricular aneurysm. Angina pectoris and congestive heart failure are most common clinical manifestations Ventricular tachycardia and systemic embolization are also complained. Using cardiopulmonary bypass, aneurysmectomy alone or combination with coronary artery revasculization are currently done for surgical treatment with steady improvenment of mortality. The first patient was 33 years old man who had true type of ventricular aneurysm on inferior wall the left ventricle near apex with protruded huge organized thrombus. The thromboembolic phenomenon was noted on both lower extremities. Under cardiopulmonary bypass, aneurysmectomy and thrombectomy were done. The aneurysmal orifice was repaired with Teflon buttless suture. The second patient was 30 years old female who had large true type of ventricular aneurysm on inferior wall of the left ventricle. Under cardiopulmonary bypass, aneurysmectomy with repair of aneurysmmal orifice defect by means of double layered Dacron patch was done with reinforce by outer silastic sheet covering. She was discharged from hospoital at post op. 15th day uneventfully.

• 한국해안·해양공학회논문집
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• 제21권3호
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• pp.224-229
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• 2009

케이슨식 안벽의 Level I 신뢰성설계를 위한 부분안전계수를 산정하였다. 일계신뢰도법에 의한 부분안전계수는 한계상태함수의 확률변수에 대한 민감도, 목표신뢰도지수, 확률특성치 및 설계특성치 등의 함수로써 표현하였으며 전면조위와 잔류수위에 대해서는 현행설계법과의 연계성을 유지하기 위하여 수정부분안전계수를 새롭게 정의하였다. 수치해석을 통하여 목표신뢰도지수에 대한 부분안전계수를 산정하였으며 지진계수의 확률분포는 극치분포를 사용하였다. 지진계수의 설계치를 적용함에 있어서 재현주기가 길수록 부분안전계수가 작게 산정됨을 확인하였다.

• 한국유체기계학회 논문집
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• 제7권6호
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• pp.45-54
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• 2004

Governing equations and numerical solution methods are derived for the analysis of a combination-type-staggered-labyrinth seal used in high performance steam turbines. A bulk flow is assumed for each combination-type-staggered-labyrinth cavity. Axial flow through a throttling labyrinth strip is determined by Neumann's leakage equation and circumferential flow is assumed to be completely turbulent in the labyrinth cavity. Moody's wall-friction-factor formula is used for the calculation of wall shear stresses. For the reaction force developed by the seal, linearized zeroth-order and first-order perturbation equations are developed for small motion near the centered position. Integration of the resultant first-order pressure distribution along and around the seal defines the rotordynamic coefficients of the combination-type-staggered-labyrinth seal. Theoretical results of leakage and rotordynamic characteristics for the IP4-stage seal of USC (ultra super critical) steam turbine are shown with the effect of sump pressure, the number of throttling labyrinth strip, and rotor speed.

• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2290-2298
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• 2020

The damage of first wall material in fusion reactor due to the bubbles caused by plasma has been studied by introducing a relation between the von Mises equivalent stress and the temperature field. The locations and shapes of the bubbles and the synergetic effect between the different bubbles under steady operational conditions have been studied using the finite elements method. Under transient heat loads, plastic deformations have been found to occur, and are significantly enhanced by the presence of the bubbles. The calculated concentration locations of von Mises equivalent stress are well consistent with the observed crack positions of the tungsten surface in many test experiments. Our simulations show that the damage of the bubbles is not severe enough to lead to catastrophic failure of the tungsten armor; however, it can cause local and gradual detachment of tungsten surface, which provides a reasonable explanation for the observed pits and rough or hairy surface morphology etc. Considering the transient heat loads, the lower bound of the security thickness of the tungsten tile is estimated to be greater than 2 mm.

• 대한기계학회논문집B
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• 제25권3호
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• pp.405-413
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• 2001

The present study investigates convective heat/mass transfer and flow characteristics inside a rotating two-pass rectangular duct. A naphthalene sublimation technique is employed to determine the detailed local heat transfer coefficients using the heat and mass transfer analogy. The objective of this study is to determine the effects of turning geometry with rotation for 0.0$\leq$Ro$\leq$0.24. The results reveal that the sharp-turn corner has the larger pressure drop and lower heat transfer in the post-turn region than those of the round-turn corner. The strong secondary flow enhances heat transfer for the round-turn corner. Coriolis force induced by the rotation pushes the high momentum core flow toward the trailing wall in the first passage with radially outward flow and toward the leading wall in the second passage with radially inward flow. Consequently, the high heat transfer rates are generated on the trailing surface and the leading surface in the first and second passage, respectively. However, the strong secondary flow due to the turning dominates the flow pattern in the second passage, thus the heat transfer differences between the leading and trailing surfaces are small with the rotation.

• 대한두개안면성형외과학회지
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• 제10권2호
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• pp.67-70
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• 2009

Purpose: Anatomical basis around orbit can be helpful in periorbital surgery, and there are many articles about measurement between periorbital reference points. In 1967, Jones and Evans measured the orbital wall thickness of Asian cadavers and this article has been cited more than 50 times. But there is no research in orbital thickness in Vivo. Author's idea was based on difference between live human and human cadaver. Material & Method: We conducted this study from 63 consecutive blow out fracture patients between January, 2000 to june, 2005 by collecting the bone fragments and measured the thickness of that fragment using vernia calipers. Anatomically, orbital floor is separated two area by inferior orbital fissure and we measured each area. Three areas were zone I (medial wall), zone II (medial to inferior orbital fissure) and zone III (lateral to inferior orbital fissure). Result: When the overall results were considered, the thickness of Zone I (medial wall of orbit) was average $0.131{\pm}0.006mm$ in male and $0.129{\pm}0.007mm$ in female and Zone II (medial side of orbital floor) was $0.251{\pm}0.005mm$ in male and $0.245{\pm}0.006mm$ in female, Zone III (lateral side of orbital floor) was $0.237{\pm}0.006mm$ in male and $0.226{\pm}0.006mm$ in female. There were no statistical difference between orbital wall thickness of male and female. Also, orbital wall thickness of adults measured $0.130{\pm}0.005mm$, $0.250{\pm}0.005mm$, $0.232{\pm}0.006mm$ in Zone I, Zone II, Zone III and $0.128{\pm}0.006mm$, $0.233{\pm}0.005mm$, $0.215{\pm}0.007mm$ in Zone I, Zone II, Zone III from childs, and there were no statistical difference between adult and child. Conclusion: This article is the first study about Korean orbital wall thickness, and can be helpful to periocular surgery.

• Spatial Information Research
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• 제14권3호
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• pp.349-361
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• 2006

국내외적으로 농촌 경관에 대한 관심과 함께 경관에 대한 관리 및 보전에 노력을 기울이고 있다. 천혜의 자연조건과 함께 아름다운 농촌경관을 유지하고 있는 제주도에서도 경관의 중요성을 인식하여 제주국제자유도시특별법 및 동법 시행조례로서 경관관리를 하고 있다. 그러나 이러한 경관관리에 대한 노력에도 무분별한 건축물의 난립 등으로 인하여 경관훼손이 가해져 체계적인 관리방안이 시급한 처지이다. 이러한 농촌경관 가운데에서도 대표적인 경관을 구성하는 돌담의 훼손이 심각히 진행되어지고 있지만 현재의 경관관리는 조망지역의 가시권에 대해서만 초점을 맞추고 있고 중요한 경관요소에 대해서는 경관평가 항목에 포함되어 있지 않아 돌담 경관의 훼손에 대해 아무런 조치를 취할 수 없는 실정에 있다. 이러한 배경 하에 본 연구는 제주도 돌담이 경관 요소로서 가지고 있는 중요한 내재적 가치를 정립하였고 또한 기존의 가시권 중심의 조망지점 경관분석에서 훼손 가능성을 경관분석에 적용함으로서 보전측면을 강화한 경관평가를 제안하였다. 또한 GIS를 활용하여 돌담 경관 실태와 훼손정도를 추정하여 GIS 기술의 활용여부도 검토하였다. 이 연구를 위해 제주도의 대표성을 지니는 한경, 애월, 신촌 등 여섯 군데의 농촌지역을 사례지역으로 정하였으며 이 지역에 대한 경관분석을 실시하였다.