• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.405-411
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• 2000

This study reviews qualitatively the flow characteristics around th tidal gap during seadike closures using a three-dimensional model for shallow water equations. The Princeton Ocean Model(POM) was adapted and applied to the Sihwa Seadike which was closed in 1994. The simulated flow patterns around the gap showed that tidal velocities increase with the cross-sectional area during ebb tide. The accelerated flow extended to wider zones passing the gap, and shock waves were generated. Vertical tidal velocity profiles were affected as the bottom scours developed beyond normal conditions.

• Nuclear Engineering and Technology
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• 제39권3호
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• pp.161-170
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• 2007

Metal fuel, which was abandoned in the 1960's in favor of oxide fuel, has since then proven to be a viable fast reactor fuel. Key discoveries allowed high burnup capability and excellent steady-state as well as off-normal performance characteristics. Metal fuel is a key to achieving inherent passive safety characteristics and compact and economic fuel cycle closure based on electrorefining and injection-casting refabrication.

• Journal of Chest Surgery
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• 제20권3호
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• pp.451-457
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• 1987

Reoperations following cardiac surgery have an increased risk of the danger of damaging the heart, great vessels or extracardiac grafts because of adhesions to the sternum. We experimentally evaluated 3 different methods for pericardial closure. A standardized procedure for induction of pericardial adhesions was carried out in 30 rabbits. For closure of pericardium, animals were divided into 3 groups, 10 animals respectively: Croup 1 [simple pericardial closure]The pericardium was primarily resuture; Group 2 [Core-Tex surgical membrane as a pericardial substitute]- A Gore-Tex surgical membrane was interposed between the sternum and the heart; and Group 3 [pericardial tension releasing technique]-Three longitudinal overlapping incisions were made on the right side of the pericardium while the midline incison was sutured. Animals were put to death 4 weeks postoperatively and the pericardial space was examined for pericardial adhesions and epicardial reactions. The extent of adhesions and reactions were graded as: I-none; II-minimal; III-moderate; and IV-severe. Histologic studies of the pericardium, the pericardial substitute and the epicardium were also performed. The results were as follows: 1. In group 1 [simple pericardial closure], the degree of pericardial adhesions were grade I in 1 animal, grade II in 2, grade III in 4 and grade IV in 3. Epicardial reactions were grade I in 1 animal, grade II in 3, grade III in 5 and grade IV in 1. Histologic examination revealed thick fibrous tissue that obliterated the pericardial space in 7 animals. 2. In group 2 [Gore-Tex surgical membrane as a pericardial substitute], the degree of pericardial adhesions were grade I in 3 animals, grade II in 3, grade III in 2 and grade IV in 2. The degree of epicardial reactions were grade II in 1 animal, grade III in 5 and grade IV in 4. Histologic studies revealed a thin layer of dense fibrous tissue which covered the Gore-Tex surgical membrane and thick loose fibrous tissue on the epicardium just beneath the substitute. 3. In group 3 [pericardial tension releasing technique], the degree of pericardial adhesions were grade I in 3 animals, grade II in 4, grade III in 2 and grade IV in 1. The degree of epicardial reactions were grade 1 in 4 animals, grade II in 4 and grade III in 2. Severe epicardial reactions were not observed in this group. Histologic examination showed normal epicardium in 4 animals and the epicardium of the other 6 animals only revealed very thin fibrous layer compared to group I and group II. Pericardial adhesions more than grade III were 70% in group 1, 40% in group 2 and 30% in group 3. Pericardial adhesions were reduced in group 2 and group 3 compared to group 1, but statistically not significant. Epicardial reactions more than grade III were 60% in group 1, 90% in group 2 and 20% in group 3. Epicardial reactions were significantly reduced in group 3 compared to group 2. Author`s modified pericardial releasing technique provides marked augment of pericardial surface area and facilitates tension-free pericardial closure. Furthermore, pericardial adhesion and epicardial reaction will be reduced with the pericardial tension releasing technique.

• 대한치과마취과학회지
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• 제1권1호
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• pp.26-31
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• 2001

The wide deep penetrating wound of maxillofacial region should be early closed under emergency general anesthesia for the prevention of complications of bleeding, infection, shock & residual scars. But, if the emergency general anesthesia wound be impossible because of pneumoconiosis, obstructive pulmonary disease & hypovolemic shock, early primary closure should be done under local anesthesia by use of much amount of the anesthetic solution. The maximum dose of dental lidocaine (2% lidocaine with 1 : 100,000 epinephrine) is reported to 7 mg/kg under 500 mg (13.8 ampules) in normal adult. But the maximum permissible dose of dental lidocaine can be changed owing to the general health, rapidity of injection, resorption, distribution & excretion of the drug. The blood level of overdose toxicity is above $4.0{\mu}g/ml$ in central nervous & cardiovascular system. The injection of dental lidocaine 1-4 ampules is attained to the blood level of $1{\mu}g/ml$ in normal healthy adult. The duration of anesthetic action in the dental 2% lidocaine hydrochloride with 1 : 100.000 epinephrine is 45 to 75 minutes and the period to elimination is about 2 to 4 hours. Therefore, authors selected the following anesthetic methods that the first injection of 6 ampules is applied into the deeper periosteal layer for anesthetic action during 1 hour, the second injection into the deeper muscle & fascial layer, the third injection into the superficial muscle and fascial layer, the fourth injection into the proximal skin & subcutaneous tissue and the fifth final injection into the distal skin & subcutaneous tissue. The total 26-28 ampules of dental lidocaine were injected into the wound as the regular time interval during 5-6 hours, but there were no systemic complications, such as, agitation, talkativeness, convulsion and specific change of vital signs and consciousness.

• Journal of Chest Surgery
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• 제28권2호
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• pp.136-142
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• 1995

A clinical study was performed on 69 cases of isolated PDA surgically treated at the Department of Thoracic and Cardiovascular surgery of Kyung-Hee University Hospital from Mar. 1986 to Feb. 1994. Retrospective clinical analysis of these patients were as follows: 1.23 males and 46 females ranged in age from 16 days to 49 years. [mean 8.69yrs.,sex ratio M:F=1:2 2. Chief complaints were frequent URI in 44%, dyspnea on exertion in 16%,palpitation in 8%, easy fatigability in 6%, and no subjective symptoms in 26%. 3. On auscultation, typical continuous machinery murmur heard in 84%, and systolic murmur in 16% on Lt 2nd or 3rd intercostal space. 4. Simple chest x- ray showed increased pulmonary vascularity in 67%, cardiomegaly in 61%,and within normal limit in 16%. 5. EKG findings were LVH in 42%, biventricular hypertrophy in 17%, RVH in 3%, and within normal limit in 38%. 6. Echocardiogram was performed from all patient, and direct visualization of ductus in 93% 7. Cardiac catheterization was performed in 39 patients. The mean value of the results were;Differance SaO2[MPA-RV =11.03$\pm$ 5.26%,Qp/Qs=2.44$\pm$1.35,systolic pulmonary arterial pressure=40.69 $\pm$ 17.69mmHg. 8. 66 patients were operated through the left posterolateral thoracoctomy ; closure of ductus by double ligation in 43 cases, triple ligation in 23 cases.3 patients were operated by simple closure under cardiopulmonary bypass. 9. There was no death associated with the operation. The operative complications were atelectasis in 8 cases, pneumonia in 4 cases recannalization in 2 cases, and hoarseness in one case. 10. Systemic diastolic pressure was increased 8.12$\pm$ 0.13mmHg, and pulse pressure was decreased about 9.52 $\pm$ 1.87mmHg.

• Archives of Plastic Surgery
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• 제41권4호
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• pp.403-406
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• 2014

Background Perforations in the nasal septum (NSP) give rise not only to disintegration of the septum anatomy but also impairment in normal nasal physiology. The successes of these surgical techniques are usually equated to anatomical closure of the perforation. The goal of this study is to evaluate the subjective and objective results of our surgical technique for septal perforation surgery. Methods All NSPs in the six patients were closed by inferior turbinate flap. The Nasal Obstruction Symptom Evaluation (NOSE) instrument was used to evaluate the preoperative and postoperative subjective sensation of nasal obstruction. Measurement of preoperative and postoperative nasal airway resistance was performed using active anterior rhinomanometry which is an objective test. Wilcoxson signed rank test and Spearman correlation test were used to analyze correlation between NOSE scores and rhinomanometric measurements. Results The full closure of the septal perforations was noted in 100% of patients. The total NOSE score was 14 preoperatively and one postoperatively. The improvement in NOSE scores was statistically significant ($P{\leq}0.002$). The mean preoperative total resistance (ResT150) value was $0.13Pa/cm^3s^{-1}$, which is below the normal range ($0.16-0.31Pa/cm^3s^{-1}$), while the mean postoperative ResT150 value was $0.27Pa/cm^3s^{-1}$. The correlation between the improvement in NOSE scores and improvements in ResT150 values was statistically significant. Conclusions Surgical approaches should aim to solve both the anatomical and physiological problems of NSP. The application of subjective and objective tests in the postoperative period will help surgeons assess the applied techniques.

• 대한치과보철학회지
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• 제32권4호
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• pp.565-572
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• 1994

According to the classification of dental arch form and the analysis of patterns of chewing movement, the patterns of chewing movement in each group were evaluated and compared with those of the normal group. Results were summarized as follows ; 1. Opening phase in chewing movement In the group which the maxillary second molar positionsbuccal side, the chewing patterns which have the Vertical Guide Openings in frontal plane, the Posterior Guide Openings in hjorizontal plane were observed. In the group which the maxillary premolars position lingual side, the chewing paterns which have the Protrusive Shift Openings in horizontal plane and sagittal plane were observed. 2. Closing phase in chewing movement. In each group except for the normal group, the chewing patterns which have the Concave Closure in frontal plane and in Horizontal plane were observed. In the group which the maxillary premolars position buccal side, the chewing patterns which have the Lateral Guide Closure in frontal plane and in horizontal plane, the Vertical Guide Closre in sagittal plane were observed: From the results, as the characteristics of the dental arch form have appeared in chewing movement, the close relationships were found between dental arch form and chewing movement. It is suggested that the evaluation of dental arch form is effective in the diagnosis of function of stomatognathic system.

• 대한기계학회논문집A
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• 제21권10호
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• pp.1694-1701
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• 1997

The residual safety assessment of steel structures, an important subject in practice, is given to much attention. Life prediction in the planning course of steel structures under fatigue loading is mainly based on fatigue design criteria resulting from S-N curves. But for any reason cracks have to be assumed due to fabrication failures or fatigue loading in service which can lead total fracture of structures. The life prediction can be carried out by means of fracture mechanics using Paris-Erdogan equation($da/dN=C {\cdot}{\Delta}K^m$). The paper presents results from charpy test to interpret transition behaviour of charpy energy($A_V$) in a wide temperature range and from constant-load-amplitude test to measure fatigue crack growth of various steels widely used in steel bridges since beginning of 20 centuries in Europe. In the normal service temperature range of steel bridges, the steel S355M shows higher maximum charpy energy($A_{Vmax}$) and lower transition temperature($T_{AVmax/2}$) than other steels considered. The C and m of Paris-Erdogan equation on the steels appear to be correlated, and to be affected by the R-ratios due to crack closure, especially at a low fatigue crack growth rate. Scanning electron microscopy analysis was carried out to interpret an influence of the crack closure effects on the correlation of C and m.

• 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.

• Clinical and Experimental Pediatrics
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• 제54권2호
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• pp.86-89
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• 2011

Traumatic ventricular septal defect (VSD) resulting from blunt chest injury is a very rare event. The mechanisms of traumatic VSD have been of little concern to dateuntil now, but two dominant theories have been described. In one, the rupture occurs due to acute compression of the heart; in the other, it is due to myocardial infarction of the septum. The clinical symptoms and timing of presentation are variable, so appropriate diagnosis can be difficult or delayed. Closure of traumatic VSD has been based on a combination of heart failure symptoms, hemodynamics, and defect size. Here, we present a case of a 4-year-old boy who presented with a traumatic VSD following a car accident. He showed normal cardiac structure at the time of injury, but after 8 days, his repeated echocardiography revealed a VSD. He was successfully treated by surgical closure of the VSD, and has been doing well up to the present. This report suggests that the clinician should pay great close attention to the patients injured by blunt chest trauma, keeping in mind the possibility of cardiac injury.