• Journal of Astronomy and Space Sciences
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• 제9권2호
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• pp.171-182
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• 1992

Radiation due to accretion from an accretion disc around the intermediate polars and photoabsorption of this radiation in the accretion funnel have been taken into account as a phenomenological model to study the physics of the magnetic funnel in the magnetic compact star. The first results show that such a model scenario can be used to estimate some parameters in these systems. Some constraints of this model regarding to the observational data of one intermediate polar, EX Hya, are also discussed.

• Journal of Chest Surgery
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• 제19권3호
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• pp.479-483
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• 1986

Two patients with funnel chest deformity were corrected at the Department of Thoracic Surgery of Chosun University Hospital. The first case was 5 year old boy, suffering cosmetic deformity, of which hollow cavity was measured 25ml of water. He was corrected by modified Ravitch method. The second case was 12 year old boy, suffering from exertional dyspnea with symmetrical funnel chest deformity, of which hollow cavity was measured 55ml of water. He was corrected by method of sternal turnover. The surgical results of these cases were satisfactory.

• Journal of Chest Surgery
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• 제23권2호
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• pp.316-324
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• 1990

This study is a review of the early postoperative results in fifteen patients who diagnosed funnel chest and underwent the corrective surgical procedure by the sternal turnover[STO] or the sternocostal elevation[SCE] between January 1988 and February 1990. Thirteen among fifteen patients were male. Early eight patients were corrected by the STO and late seven patients by the SCE. Cosmetic result was excellent in one, fair in five, poor in two patients who received the STO and excellent in all patients corrected by the SCE. This unfavorable postoperative result in the STO group was due to the protrusion of inverted xiphisternal joint, the depression along the rejoined costal cartilages and forward tilting of the distal sternum. The lower vertebral indices measured on the lateral chest film were improved postoperatively from 0.42\ulcorner0.08 to 0.30\ulcorner0.05 in the STO group and from 0.31\ulcorner0.05 to 0.24\ulcorner0.03 in the SCE group. There was significant improvement in lower vertebral index in both groups, but it was difficult to compare the postoperative improvement between groups due to the different preoperative status. In the SCE group, the funnel index and the degree of depression measured on the computed tomography were significantly improved from 5.29\ulcorner1.72 and 3.11\ulcorner0.71 to 2.77\ulcorner0.46 and 1.63\ulcorner0.19[P<0.05], but there was no significant change in the degree of flatness postoperatively. This results suggest that sternocostal elevation is more cosmetic procedure than sternal turnover in children and in young adolescents whose funnel index measured on the computed tomography is low.

• 한국토양동물학회지
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• 제5권2호
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• pp.63-70
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• 2000

영국의 고원지대 (Moorland)의 이탄토양 (blanket bog peat soil에 서식하는 애지렁이 정량조사를 위한 수분갈때기추출법의 효율에 미치는 수온, 물의 량, 추출시간의 복합적인 효과를 조사하였다. 이탄 토양에서 애지렁이 추출을 위한 최적조건은 물의 양과 초기 수온에 관계없이 표면수의 최종 온도는 35$^{\circ}C$이고, 추출시간은 6시간이었다. O'Connor의 방법 (최종 온도 40-45$^{\circ}C$,열의 점진적인 증가, 3시간 추출)은 비교적 늪은 온도와 짧은 추출시간으로 인해, 추출효율에 변이가 심하였다. 열을 가하지 않고 장시간 추출하는 방식은 열을 가하는 방식에 비해 추출효율이 현저히 낮았다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.317-320
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• 2008

본 연구는 최근 건축물의 대형화 다양화 되어감에 따라 초고강도 콘크리트에 대한 높은 관심과 연구가 활발하게 이루어지고 있는 상황에서 국내에서도 200MP급 이상의 초고강도 콘크리트가 개발 되었고, 150MPa의 초고강도 콘크리트의 실용화 연구가 진행되고 있는 상황이다. 하지만, 100MPa급 이상의 초고강도 콘크리트는 물-결합재비가 낮기 때문에 점성이 높아 기존의 슬럼프 실험만으로는 유동성을 평가하기에는 부족하기 때문에 레올로지(rheology)를 이용한 평가와 O-lot, V-funnel 실험 평가를 하여 상관 관계를 밝힘으로써 100MPa급 이상의 초고강도 콘크리트의 실용화를 위한 기본 정보를 제공하는데 그 목적을 두었다. 실험 결과, Yield stress과 slump flow, V-funnel는 높은 상관관계가 있음을 알 수 있었고, plastic viscosity도 O-lot시간과 V-funnel시간과 높은 상관관계가 있음을 알 수 있었다.

• 한국도로학회논문집
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• 제19권5호
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• pp.77-88
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• 2017

PURPOSES : It is necessary to clarify the rheological properties of cement paste as a basic research in the development of mechanistic concrete mix design. The rheological properties of cement paste with different binder types, mix propositions, and with/without high range water reducers have been analyzed. METHODS : In this study, ordinary Portland cement, fly-ash, blast furnace slag, silica fume, and limestone powder were used as binders. The range of water-binder ratio was 0.3-0.5, and a total of 30 different mixes have been tested. The slump flow test, V-funnel test, and Dynamic Shear Rheometer (DSR) test were performed to analyze the rheological properties of cement paste. RESULTS : As a result of the slump flow test, it was found that the composition ratio of the binder contents greatly affected the paste flow when the high range water reducers were added. The results of V-funnel test showed that when the water-binder ratio was decreased without high range water reducers, the binder composition ratio had a large effect on the passing time of the V-funnel tester, but with high range water reducers the impact of the binder composition ratio was decreased. The slump flow and V-funnel have a certain relationship with the rheological factors (yield stress and plastic viscosity), but the correlation was not significant. Finally, we proposed the M-value considering the density and specific surface area of the binder. The correlation between rheological factors and M-value were better demonstrated than experimental values, but there is still a limit to predict the rheological factor in general mix design. CONCLUSIONS :In this study, the rheological properties of cement paste were analyzed. The binder type, composition ratio of binder, and with/without high range water reducers have combined to provide the complex effects on the rheological properties of cement paste. The correlation between the proposed M-value and rheological factor was found to be better than experimental results, but needs to be improved in the future.

• Journal of Chest Surgery
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• 제32권4호
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• pp.399-403
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• 1999

배경: 누두흉은 가장 흔한 흉골기형으로 대부분이 선천적으로 흉골과 그 주위의 연골을 포함한 늑골의 일부가 함몰한 기형을 말한다. 누두흉의 수술방법은 Ravitch 술식에 의한 흉골거상법과 Wada 술식에 의한 흉골반전법이 주로 시행되어 왔다. 대상 및 방법: 1983년 1월부터 1996년 12월까지 누두흉의 수술적 교정을 받은 21명을 분석하였다. 환자의 연령별 분포와 동반된 기형의 종류, 동반된 증상, 각 수술방법에 따른 교정의 정도와 합병증의 유무, 환자의 술후 만족도를 조사하였다. 수술적 방법으로는 Wada술을 17례, Ravitch 술식을 4례 실시하였다. 수술적 적응증은 미용상의 이유가 가장 많았다. 결과: 술전의 Welch index는 평균 4.188 이었고 술후 3.46으로 개선되었고 Wada 술식에서 교정도가 높았다.(P=0.046) 합병증의 빈도는 Ravitch 변형술에서 높았으나 통계적 유의성은 없었다.(P=0.54) 수술후 합병증을 보인 1례를 제외한 전례에서 환자의 만족도, 술전의 정신,신체적 결함에서 회복되었고 함몰의 교정 정도에서도 만족할만한 결과를 얻었다. 수술후 외래 추적 결과 누두흉의 재발과 사망례는 없었다. 결론: 학동기전후연령과 함몰이 대칭성인 누두흉인 경우에서 흉골반전술이 좋은 술식이 된다고 생각한다.

• 환경생물
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• 제36권2호
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• pp.99-106
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• 2018

기존에 주로 논 수서생물의 채집을 위해 사용된 방형구법과 뜰채법은 높은 노동력을 요구했기 때문에 광범위한 지역을 대상으로 한 모니터링이 어려웠다. 이 연구는 논 수서생물을 보다 신속하게 채집할 수 있는 수중트랩을 사용하여 지역 및 시기별 논 수서생물의 군집 조성을 확인하였다. 수중트랩은 논을 대표하는 수서생물 중 환경 변화를 지표하거나 수조류의 먹이가 되는 이동성이 높은 종이 포함된 분류군을 채집하는 데 유용했다. 사과우렁이과 (Ampullariidae), 미꾸라지과 (Cobitidae), 물벌레과 (Corixidae), 물방개과 (Dytiscidae), 물땡땡이과 (Hydrophilidae), 물달팽이과 (Lymnaeidae) 등 15개 분류군은 논 수서생물 군집 조성을 결정했다. 주요 분류군 중 환경 교란에 강한 깔다구과 만이 논 수서생물 군집의 시기 변화를 대표했다. 인위적인 영향에 민감한 사과우렁이과, 물땡땡이과 그리고 물방개과는 지역별로 분포가 상이했다.

• Journal of Chest Surgery
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• 제20권1호
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• pp.161-170
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• 1987

Fifty-nine cases of congenital chest wall defects experienced in the department of thoracic surgery of Seoul National University Hospital were analyzed and the relevant literatures were reviewed. They are 52 cases of funnel chest, 3 cases of pigeon breast, one case of superior sternal fissure, one case of costochondral incurvation, one case of Cantrell`s pentalogy, and one case of Poland`s syndrome. Funnel chest affected males more frequently than females by 44 to 8. All of the funnel deformities were corrected by Ravitch operation or its modification except one which was the first case of this series and was corrected by a sterno-turnover. Two cases required a mechanical ventilation for 3 days and 5 days respectively. Four minor complications which were two cases of skin wound infection and 2 cases of fluid accumulation were noted. Skin would infection was repaired by a secondary closure and fluid accumulation was treated by aspiration only. The result are all excellent without recurrence or reoperation. In 3 cases of pigeon breast, they were treated by subperichondrial resection of all of the involved costal cartilages and shortening their course with reefing sutures in the perichondrium with excellent result. The superior sternal fissure which was combined by a ventricular septal defect was treated by a simple wire closure with a good result. The costochondral incurvation was corrected by subperichondrial resection of deformed cartilages and a rib graft removed from the contralateral normal side. The Poland syndrome and the Cantrell`s pentalogy was already presented previously.

• Journal of Chest Surgery
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• 제11권3호
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• pp.246-252
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• 1978

A three year and seven month old girl with moderate depression deformity of the sternum associated with a huge well defined homogenous hazy mass density of the upper half of the right hemithorax on plain chest x-ray had developed, exertionaI dyspnea (Figs1, 2 and 3). Correction of the funnel chest was carried out with modified Ravitch procedure and resection of the intrathoracic cystic mass was performed through an anterolateral thoracotomy incision in one stage operation satisfactorily (Figs. 7 and 8). On exploration, the mass, $15{\times}12{\times}10$cm in size, was connected to the bronchus at 1cm a bove the carina by a stalk (Fig. 4). The outer surface showed abundant vasculature. The specimen was filled with mucoid material; the inner surface was much trabeculated. glistening and smooth (Fig. 5 and 6). yficroscopically, the cyst was lined with simple or pseudostratified ciliated columnar epithelium. The cystic wall was composed of loose fibrous connective tissue, muscle layers, cartilages with some lymphocytic infiltration (Fig. 9). Isolated cases of funnel chest deformity and congenital bronchogenic cystic disease are not uncommon; however, the assocbtion of the two conditions is yery rare. Therefore. report and review of the literature was done.