• Journal of Chest Surgery
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• v.13 no.1
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• pp.60-65
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• 1980

We have experienced 2 cases of the hunshot wound sof the chest involving cardiac injuries at department of the thoracic surgery, Capital Armed Forces General Hospital during I year from April I 1979 to Jan. 1980. In one case of two patients , he was a 22 years old man who was transported to this emergency room 4 hour 10 minutes after having gunshot wound of the left chest by helicopter. Physical examination showed small inlet in left 3rd ICS and left parasternal border, large outlet in left 8th ICS and left scapular line, no breath sound on left side and distant heart sound. chest roentgenography demonstrated marked pleural effusion in left side and mediastinum shifted to right. As soon as chest X-ray was taken, the bleeding through penetrating wound became profuse and cardiac arrest ensued. Closed chest cardiac massage was started and vigorous transfusion continued, but no effective cardiac activity could not be obtained. The patient was pronounced dead due to exsanguinating hemorrhage from wuwpected cardiac wounds. In this critically injured patient with evidence of intrathoracic hemorrhage and suspected cardiac penetration, only emergency thoracic exploration and immediate surgical control of bleeding points might offer the maximum possibility of survival. The other case was a 23 years old man who was transferred to the emergency room 4 hours 50 minutes after having kmultiple communicated fractures of sternum and linear fracture of right mandible by a missile. Examination revealed about 30% skin loss of the anterior chest wall, weak pulse of 96 beats/min., distant heart sound and decreased breath sounds bilaterally. finding on the chest X-ray films showed multiple sternal fractures, marked pericardial effusion indicating hemopericardium. So, the patient was moved immediately to the operation room where, after endotracheal tube inserted, a median sternotomy was performced. A hemorrhagic congestion of the right upper lobe and marked bulging pericardium were disclosed. The pericardium was opened anterior to right phrenic nerve and exsanguinating hemorrhage ensued from the 0.5cm lacerated wound in the auricle of right atrium. The rupture site of right atrium was occluded with non-crushing vascular clamps and then was over sewn with interrupted sutures. It was thought to be highly possible that he was alive long enough to have cardiorrhaphy because of cardiac tamponade, which prevented exsanguinating hemorrhage. He was taken closed reduction for linear fracture of right mandible 2 weeks after repair of ruptured right auricle in dental clinic. This patient's post-operative course was not eventful.

• Polymer(Korea)
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• v.31 no.4
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• pp.289-296
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• 2007

The material factors influencing the sound absorption of the polyurethane foam were investigated with FT-IR, small-angle X-ray scattering (SAXS), and dynamic mechanical thermal analyzer (DMTA). The measurements were performed using the samples which had a similar cell structure but different absorption coefficients. It was found that the ability of the sound absorption of the polyurethane foams was closely related to the damping behavior over the transition range. In order to confirm the use of the low monol polyol (LMP) in high-performance applications, the polyurethanes based on LMP and polypropylene oxide polyol (PPG) were prepared by the solution polymerization method. The microstructure and the physical properties of these polyurethanes were compared. The PPG-based polyurethane showed a higher level of the phase-separated structure because the considerable amount of monol presented in PPG made a contribution to the increased chain mobility. However the short chains formed due to the monol species deteriorated the damping property. As a result, the LMP-based polyurethane showed the superior damping behavior as compared with the PPG-based one.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.244-247
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• 2010

Spontaneous pneumomediastinum in the absence of predisposing risk factors has been rarely observed in full-term neonates. A 3-day-old neonate, delivered vaginally at term without any perinatal complications or signs of respiratory difficulty, was referred to the Seoul National University Children's Hospital because of reduced heart sound detected during routine neonatal examination. Chest computed tomography (CT) showed air collection in the anterior mediastinum. The baby developed respiratory distress on the fourth day and required supplemental oxygen. On the seventh day, there was no sign of respiratory difficulty, and x-ray examination showed no demonstrable pneumomediastinum. Hence, careful neonatal physical examination is essential during the postnatal assessment of newborns, and spontaneous pneumomediastinum should be considered when a healthy newborn presents with reduced heart sound.

• The Journal of the Acoustical Society of Korea
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• v.34 no.2
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• pp.98-107
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• 2015

It is investigated that there exists the possibility of the false target signals induced by reverberation in an active sonar system due to the internal waves in shallow water. The rays down-refracted from the internal waves may generate strong bottom-reverberation signals, which can result in false target signals. Sound waves emitted from a source propagate 3-dimensionally. Therefore, the study of internal waves on the reverberation should be studied for azimuthal direction as well as 2-dimensional (r-z) plane. Internal-wave modelling was conducted, based on solitons which were predicted with the various conditions such as, the range of source-soliton, horizontal widths of soliton. Variable depth sonar (VDS) was assumed as a source, of which the depth was located in the minimum sound speed layer in a simulation environment. Finally, the simulation on the reverberation level with time was made based on ray-based reverberation model, and the results implied that several false-target signals could be displayed on the PPI(Plan Position Indicator) scope simultaneously with range from source to soliton, and the horizontal width of soliton.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.343-346
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• 1996

The cultured stain fungus isolated firstly from discolored wood of Pinus rigida was inoculated on wood blocks to investigate the invading pathway of the fungus. The inoculated fungus rapidly colonized in the ray parenchyma and moved radially along them. In process of time the fungus penetrated tracheids where it started to move into vertical direction. After 90 days the fungus colonized all over the wood tissue, therefore some cell lumens were filled with full of hyphae. In addition methanol extracts did not affect the invading pathway of the stain fungus.

• Korean Journal of Materials Research
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• v.26 no.10
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• pp.521-527
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• 2016

Geopolymers have many advantages over Portland cement, including energy efficiency, reduced greenhouse gas emissions, high strength at early age and improved thermal resistance. Alkali activated geopolymers made from waste materials such as fly ash or blast furnace slag are particularly advantageous because of their environmental sustainability and low cost. However, their durability and functionality remain subjects for further study. Geopolymer materials can be used in various applications such as fire and heat resistant fiber composites, sealants, concretes, ceramics, etc., depending on the chemical composition of the source materials and the activators. In this study, we investigated the thermal properties and microstructure of fly ash and blast furnace slag based geopolymers in order to develop eco-friendly construction materials with excellent energy efficiency, sound insulation properties and good heat resistance. With different curing times, specimens of various compositions were investigated in terms of compressive strength, X-ray diffraction, thermal property and microstructure. In addition, we investigated changes in X-ray diffraction and microstructure for geopolymers exposed to $1,000^{\circ}C$ heat.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.499-504
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• 2012

The high-speed train enjoys widespread acceptance as environment-friendly means of medium- to long-distance transportation. The pursuit of higher speed and lighter weight in railroad vehicles has engendered higher noise level. In particular, the environmental noise places many restrictions in the operation of high-speed railroad vehicles. This research investigates the effect of installing a skirt onto a high-speed train bogie with the top speed of 400 km/hr and using High Speed EMU for the purpose of reducing the environmental noise. In order to analyze the effect of the interior noise and environmental noise due to installation of the skirt, sound level is calculated using the Ray method and Statical Energy Analysis method. The numerical calculation predicts a reduction of approximately 2 dB in the environmental noise level, but at the cost of increase of approximately 2.5 dB in the interior noise level of the vehicle.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.325-328
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• 1996

The cultured stain fungus isolated firstly from discolored wood of Pinus rigida was inoculated on wood blocks to investigate the invading pathway of the fungus. The inoculated fungus rapidly colonized in the ray parenchyma and moved radially along them. In process of time the fungus penetrated tracheids where it started to move into vertical direction. After 90 days the fungus colonized all over the wood tissue, therefore some cell lumens were filled with full of hyphae. In addition methanol extracts did not affect the invading pathway of the stain fungus.

• The Journal of Internal Korean Medicine
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• v.22 no.3
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• pp.489-494
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• 2001

Pneumonia is the disease caused by inflammation of lung parenchyma. Major symptoms of pneumonia are fever, cough, etc and consolidation is seen in chest x-ray. When pleurisy gets in complication of pneumonia, pleural effusion occurs. Also chest pain occurs by pleurisy. Gyulhyung is the disease of which major symptom is chest pain. Sugyulhyung from in Gyulhyung, the water sound is audible from the flank side the fact that as Sugyulhyung. Symptom of Gyulhyung is similar to that of pneumonia. We diagnosed this case as Gyulhyung and administrated Banhabogryeongtang to patient. As result, there is remarkable Improvement in symptom and chest x-ray.

• The Journal of the Acoustical Society of Korea
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• v.20 no.4
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• pp.5-11
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• 2001

Acoustic characteristics of the wedge-shaped anechoic tiles, used as absorbing lining materials for an anechoic water tank, were investigated for different wedge-apex angles. The anechoic tile base has the dimensions of 400mm x 385mm x 15.5mm. In order to investigate anechoic effect, the wedge-apex angles 30° and 60° were selected by using a ray-tracing method. The reflection loss of the anechoic tiles with and without wedges were experimentally studied at normal incident sound waves in water. In this experiment, the reflection loss of wedge-shaped anechoic tiles with the optimum wedge-apex angle 30° is larger than one with the angle 60° and one without wedges. The experimental results show that the wedge-shaped anechoic tiles with the wedge-apex angle 30°, optimized by using ray-tracing method, turn out better absorbing lining materials of an anechoic water tank.