• 한국발생생물학회지:발생과생식
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• 제4권1호
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• pp.1-6
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• 2000

광학, 주사 및 투과전자현미경을 이용하여 무지개송어(Oncorhynchus mykiss) 성숙난자의 방사대와 난문 및 정자가 난문으로부터 난세포질까지 침투하는 과정의 미세구조를 조사하였다. 무지개송어의 난문은 깔때기 모양의 전정부와 방사대를 가로 지르는 나사선 모양의 도관으로 구성되어 있었다. 난문은 윗부분은 편평하면서 긴 도관 모양을 가지고 있었고, 난문벽은 시계방향(우선형)의 구조를 나타내었다. 난문 주변부에 있는 난표면에는 정자를 접촉시키는 데 필요한 유인물 질을 분비하는 무수한 많은 돌출물이 원을 이루면서 존재하였다. 침투 초기단계에 난문의 도관에 있는 한 마리의 정자는 난표면에 수직상태로 확인되었고, 곧이어 수정이 이루어진지 250초가 경과하자 정자두부는 사라지게 되었다. 정자두부가 난내부로 침투한 이후에 난표면에 있던 돌출물의 상호연결부위는 관찰되지 않았다. 다른 부위로 정자가 침투하는 지를 살펴보았지만 그러한 흔적은 확인되지 않았다. 난문의 수정추의 형태적인 구조를 관찰한 결과 이 미세구조물은 단 한 마리의 정자만을 허용함으로써 다정자침입을 방지하는 것으로 확인되었다.

• 한국임상수의학회지
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• 제30권1호
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• pp.80-85
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• 2013

Twenty one cows in Goyang and Paju cities were referred due to displacement of the abomasum and foreign body in the rumen. Omentopexy and rumenotomy through a right flank celiotomy were performed for treatment of abomasal displacement and the foreign body removal in the rumen. The right paralumbar fossa is clipped and prepared surgically. Local anesthesia is instituted by performing inverted L block. The abdomen was entered through 25 to 30 cm vertical incision in the right paralumbar fossa starting 4 to 5 cm ventral to the transverse processes of the lumbar vertebrae. A 14-gauge needle with rubber tubing attached is inserted to relieve the gaseous pressure and to facilitate further exploration and manipulation. The rumen was gently pulled out of the abdominal cavity and incision was made at the omentum. Rumenotomy was done and retrieved the foreign body. After the rumen was rinsed with sterile saline, the rumen wall was closed by a Lembert suture technique. The omentum was closed by a simple continuous suture. Right flank omentopexy was performed for the surgical correction of abomasal displacement. Recovery results among 21 cows included 9 excellent, 5 good, 2 fair and 5 bad. It was considered that operation of abomasal displacement and foreign body removal in the rumen through right flank celiotomy was a good surgical technique to reduce expenses, surgical pain, and surgery time.

• 터널과지하공간
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• 제28권2호
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• pp.142-155
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• 2018

${\bigcirc}{\bigcirc}$광산은 광체주변에 미고결된 층서가 불규칙하게 발달되어 있다. 본 연구는 효율적인 루프볼트(roof bolt) 시공을 위하여 불규칙한 층서의 두께를 체계적으로 배열하고 이에 대응하는 지보시스템을 제시한 것이다. 층서별 두께를 조합한 81개의 경우의 수를 강건설계에 의하여 9개의 사례로 한정하여 지보설계를 하였다. 각 사례에 대하여 천반하중으로 작용할 수 있는 하중고를 층서의 특성과 RMR에 의하여 결정하였다. 하중고에 의한 하중범위를 블록형상과 아치형상으로 가정하여 계산하였다. 두 방법의 평균하중으로 루프볼트의 지보력을 감안한 지보설계를 하였다. 지보설계에 대한 수치해석 결과 케이블 볼트는 선단정착 방식보다 전면접착 방식이 천반유지에 더 효과적인 것으로 분석되었다. 시공결과 천반의 컨트롤은 가능하였으나 갱도측벽의 변형으로 천반 전체가 하부로 조금씩 침강하는 현상을 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권3호
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• pp.320-325
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• 2005

Effect of period of adaptation and levels of monensin were studied for microbial fermentation/ digestibility to find out the optimum period of adaptation of monensin in rumen and suitable level of monensin in wheat straw+concentrate and wheat straw+UMMB diet. The mean digestibility of dry matter was decreased upto T-3 treatment (49.17%), however, digestibility of DM was affected upto period (P-2). NDF digestibility was affected due to treatment under P1 and P2 (p<0.05). Average digestibility of ADF was increased to 53.33% at T-3 level of monensin and P4 days of adaptation. TVFA (mmole/100 ml) were decreased from 9.49 in T-1 to 7.70 in T-7. Periods were not effectives except P2 (14 days of adaptation). Similarly, total gas was decrease with the increase of monensin levels in diet. Although acetate percentage in TVFA was not affected either due to level of monensin or period of adaptation but propionate was increased due to increase in monensin at 21 days of adaptation (P-3). Butyrate (%) was decreased significantly in T-2 to T-6 as compared to T-1 group. Total gas was significantly (p<0.01) higher in group T-1 (control) and it reduced significantly in T-5, however, differences in gas production between group T-3, T-5 and T-7 at P-1 was not significant. Methane production was reduced on P-3 and P-4 level of adaptation due to treatment. The overall result indicated that 21 days of adaptation with monensin was sufficient to mask the inhibiting effect of monensin to cell wall digestibility and 35 ppm monensin is optimum to reduce methane production and increase propionate productions.

• 해양환경안전학회지
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• 제15권2호
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• pp.127-133
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• 2009

묘도-광양간 현수교는 광양항에 진입하는 항로에 위치해있으므로 큰 배들에 대하여 충돌 방지공이 필요하다. 본 논문은 선박충돌을 고려하여 위험도 분석과 비선형 수치해석을 실시하였다. 위험도 분석 결과 충돌 방지공 설치 이전에는 연간 파괴확률이 기준치인 0.0001을 초과하여 충돌 방지공이 필요한 것으로 분석되었다. 따라서, 선박의 충돌을 방지하기 위해서 인공섬과 콘리트트 블록으로 만든 방파제 벽을 사용하여 설계하였다. 계획된 충돌 방지공 설치 후 비선형 수치해석 결과 교량에 미치는 하중이 교량의 내하력 이내로 나타나 선박 충돌시에도 교량의 안정성이 확보되는 것으로 나타났다.

• 수산해양기술연구
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• 제47권1호
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• pp.1-9
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• 2011

In order to investigate the cause and magnitude of scale effect occurring in the model experiments of fishing nets, five pairs of Nylon pyramid nets and one pair of PE ones in which all the two nets paired were equal each other in the factors determining their flow resistance, i. e., the ratio d/l of diameter d to length l of bars, the angle f between two adjacent bars, the attack angle q of nettings to the water flow, and the wall area S of nets, and different in the values of d and l were prepared. Then, the nets were attached to the circular steel frame alternately and their flow resistances with shapes in water were measured on the sea ascribing no turbulent flows by using the tension meter made of a block bearing for the experiment. All the Nylon nets were spreads out easily in water to form a circular cone at relatively low velocity of water and showed the resistance smaller a little in the nets with larger d and l than them with smaller d and l, because the filtration of water through meshes become easier in nets especially with larger l. But PE nettings were not spread out sufficiently on account of their small flexibility and showed higher resistance especially in them with thicker twines. Therefore, the difference in bar length or mesh size and flexibility of nettings between prototype and model nets are regarded to become factors ascribing scale effect. Especially the influence of the difference in mesh size may become large significantly in actual model experiments because the mesh size of model nets is decided at much larger value than that given by scale ratio and so the difference of mesh size between the two nets become much larger than that between nets used in this experiment.

• 한국화재소방학회논문지
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• 제11권1호
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• pp.21-35
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• 1997

The natural convection and combined heat transfer induced by fire in a rectangular enclosure is numerically studied. The model for this numerical analysis is partially opened right wall. The solution procedure includes the standard k-$\varepsilon$ model for turbulent flow and the discrete ordinates method (DOM) is used for the calculation of radiative heat transfer equation. In numerical study, SIMPLE algorithm is applied for fluid flow analysis, and the investigations of combustion gas induced by fire is performed by FAST model of HAZARD I program. In this study, numerical simulation on the combined naturnal convection and radiation is carried out in a partial enclosure filled with absorbed-emitted gray media, but is not considered scattering problem. The streamlines, isothermal lines, average radiation intensity and kinetic energy are compared the results of pure convection with those of the combined convection-radiation, the combined heat transfer. Comparing the results of pure convection with those of the combined convection-radiation, the combined heat transfer analysis shows the stronger circulation than those of the pure convection. Three different locations of heat source are considered to observe the effect of heat source location on the heat transfer phenomena. As the results, the circulation and the heat transfer in the left region from heating block are much more influenced than those in the right region. It is also founded that the radiation effect cannot be neglected in analyzing the building in fire. And as the results of combustion gas analysis from FAST model, it is found that O2 concentration is decreased according to time. While CO and CO2 concentration are rapidly increased in the beginning(about 100sec), but slowly decreased from that time on.

• 한국전자파학회논문지
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• 제24권6호
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• pp.586-594
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• 2013

본 논문에서는 도파관 슬롯 배열 안테나 설계 시 분기 도파관 내에서 결합 슬롯과 복사 슬롯 간의 원하지 않는 고차 모드 결합을 줄일 수 있는 슬롯 커플러용 결합 요소를 제안하였다. 제안된 소자는 수직 교차하는 두 도파관이 공유하는 도파관 광벽에 위치한 중심 종방향 션트-시리즈 결합 슬롯과 이를 여기시키는 비대칭 복합아이리스로 구성된다. 먼저 HFSS를 사용하여 커플러 구조의 산란 계수를 구하고, 결합 슬롯의 T - 회로망 등가 회로의 파라미터를 추출하였다. 또한, 소자의 구조적인 치수를 변화시키면서 공진 길이 및 정규화 어드미턴스와같은 공진 특성을 분석하였다. 결합 슬롯으로부터 ${\lambda}_g/4$ 떨어진 단락 블록을 갖는 커플러를 설계 제작하여 측정한 실험 결과는 모의실험 결과와 잘 일치하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제37권8호
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• pp.843-848
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• 2013

LNG 수요의 증가에 따라, LNG FPSO (부유식 생산저장 하역설비) 선박 및 LNG 선박의 건조도 지속적으로 증가하고 있고, 다양한 형태의 저장탱크 설계가 시도되고 있다. 본 논문에서는 LNG를 저장하는 선박 화물창 내부탱크의 방식으로 5~9% Ni강재를 적용하고, 단열재를 우레탄폼 블록 대신에 펄라이트 분말을 충전하는 새로운 선박 탱크 형식을 제안하였다. 펄라이트 단열재의 적용 가능성을 위하여 필수적으로 검토되어야 하는 펄라이트의 내부탱크 벽체에 가하는 압력, 압력 흡수를 위하여 적용되는 탄성 블랭킷의 특성, 블랭킷의 적정 설계두께, 내부탱크 설계압력 등 설계 인자들을 분석하였다. 연구결과로, 블랭킷의 두께설계 기준은 내부탱크 단열간격의 1/4~1/3 사이가 되어야 하고 적정 두께는 30% 정도가 되었으며, 탱크 설계압력 기준은 블랭킷 두께에 따라 1,500 Pa 이하가 되어야 하는 것으로 얻어졌다.

• Journal of Korean Neurosurgical Society
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• 제52권5호
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• pp.491-494
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• 2012

We report a rare complication of iatrogenic spinal intradural following minimally invasive extradural endoscopic procedues in the lumbo-sacral spines. To our knowledge, intradural cyst following epiduroscopy has not been reported in the literature. A 65-year-old woman with back pain related with previous lumbar disc surgery underwent endoscopic epidural neuroplasty and nerve block, but her back pain much aggravated after this procedure. Postoperative magnetic resonance imaging revealed a large intradural cyst from S1-2 to L2-3 displacing the nerve roots anteriorly. On T1 and T2-weighted image, the signal within the cyst had the same intensity as cerebrospinal fluid. The patient underwent partial laminectomy of L5 and intradural exploration, and fenestration of the cystic wall was accomplished. During operation, the communication between the cyst and subarachnoid space was not identified, and the content of the cyst was the same as that of cerebrospinal fluid. Postoperatively, the pain attenuated immediately. Incidental durotomy which occurred during advancing the endoscope through epidural space may be the cause of formation of the intradural cyst. Intrdural cyst should be considered, if a patient complains of new symptoms such as aggravation of back pain after epiduroscopy. Surgical treatment, simple fenestration of the cyst may lead to improved outcome. All the procedures using epiduroscopy should be performed with caution.