• Composites Research
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• v.21 no.2
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• pp.8-14
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• 2008

Decrease of strength in composite material is generally caused by water absorption. It makes fracture of material, and loss of money or human lives. The objective of this study is to investigate the causes of decrease in strength by water absorption. Mechanism of water absorption was supposed as three steps. This mechanism is consisted of absorption into resin, absorption between resin and surface treatment agent, and delamination between fiber and resin. Conditions of test were supplied differently; kinds of fiber and resin, immersion time etc. Both of reversible reaction and irreversible reaction occurred simultaneously. Most of decrease in strength was finished at 2.5% water absorption, and the strength was recovered. At 4% water absorption, most of decrease was caused by irreversible reaction, therefore, there was a tendency not to be recovered in strength.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.1
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• pp.39-45
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• 2009

Purpose: We intended to classify the pattern and to seek the cause of fractures and/or dislocations related to middle and high school Taekwondo athletes in competition and try to get the ways for preventing them. Materials and Methods: We studied 50 fractures and dislocations of the athletes in competition, which were surveyed in 2005-2007 national middle and high school Taekwondo tournament annually. We analyzed the type and the cause of the injury, performed survey at postinjury l year in 32 cases, sought proper treatments and methods for prevention. Results: The 26 cases (52%) of foot fracture, 15 cases (30%) of hand fracture and 9 cases (18%) of forearm fracture are occurred in this study. The 9 cases (28%) of satisfaction in treatment, 15 cases (47%) of average and 8 cases (25%) of dissatisfaction are surveyed in the 32 cases. The causes of dissatisfaction are lack of rest (7 cases), excessive training (5 cases), immoderate participation of match (6 cases) and the others. The athletes were returned to the match before complete recovery in 21 cases (67%). Conclusion: The causes of fractures and dislocations in middle and high school Taekwondo athletes were stroke on upper and lower extremities and high-speed hyperflexion injury that was occurred during spraining of great toe on the floor. We consider that the athletes need the development of effective protector, improvement of equipment in stadium and enough rest and education.

• The Journal of the Petrological Society of Korea
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• v.10 no.3
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• pp.148-156
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• 2001

We report $^{230}Th/^{234}U$ disequilibrium ages of fracture-filling carbonate veins from the Ipsil and Janghangri fault zones, Gyeongju, Korea by multiple collector inductively coupled plasma mass spectrometry. The U and Th fraction was extracted from totally dissolved samples by rapid and convenient coprecipitation and ion exchange chemistry. The recovery was around 80% for Th and 70% for U. The $^{234}U/^{238}U,\;^{230}Th/^{232}Th$ ratios were analysed for this preconcentrated fraction and the U/Th ratio was directly analysed for untreated sample solution. The $^{234}U-^{230}Th$ system is in secular equilibrium for the Ipsil carbonate samples, supporting previously reported ESR ages. The detrital-corrected $^{230}Th/^{234}U$ age of the Janghangri carbonate samples is $48\pm$41 ka, which constrains the minimum age of the fracture zone.

• Journal of the Korean Institute of Gas
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• v.20 no.1
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• pp.13-22
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• 2016

This paper presents development of an appropriate procedure and flow chart to analyze shale gas production data obtained from a multi-fractured horizontal well according to flow characteristics in order to calculate an estimated ultimate recovery. Also, the technical considerations were proposed when a rate transient analysis was performed with field production data occurred to only $1^{st}$ transient flow. If production data show the $1^{st}$ transient flow from log-log and square root time plot analysis, production forecasting must be performed by applying different method as before and after of the end of $1^{st}$ linear flow. It is estimated by an area of stimulated reservoir volume which can be calculated from analysis results of micro-seismic data. If there are no bottomhole pressure data or micro-seismic data, an empirical decline curve method can be used to forecast production performance. If production period is relatively short, an accuracy of production data analysis could be improved by analyzing except the early production data, if it is necessary, after evaluating appropriation with near well data. Also, because over- or under-estimation for stimulated reservoir volume could take place according to analysis method or analyzer's own mind, it is necessary to recalculate it with fracture modeling, reservoir simulation and rate transient analysis, if it is necessary, after adequacy evaluation for fracture stage, injection volume of fracture fluid and productivity of producers.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.1-11
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• 2003

Purpose: To analysis of the result of the treatment of metastatic diaphyseal fracture of the humerus with closed interlocking intrameduallry nailing. Materials and Methods: Among surgically treated 29 patients with pathologic or impending fracture of diaphysis of the humeurs, 13 patients (16 cases) treated with closed intramedullary interlocking nail were selected for the study. The final result of pain relief and functional recovery was evaluated by modified rating system of Perez et al. Results: Primary cancer was diagnosed after fracture was developed in 2 patients and pathologic or impending fracture was occurred average period of 28.9 months after primary cancer was diagnosed. The main primary malignancies were multiple myeloma, lung cancer and breast cancer. Mean survival after humeral metastasis was 11.7 months. The final result was superior to fair in 13 of 16 cases, and poor in 3 cases with progression of tumor spread or distant dissemination to the ipsilateral fingers. Except the latter 3 patients and other 3 patients, who died before 3 months postoperatively, bony union was achieved in 10 cases. There were no complications related to surgery. Conclusion: Closed interlocking intrameduallry nailing is accomplished with brief operative time, small amount of bleeding and provides immediate stability with resultant early return of function to the arm. Additionally it allows early postoperative irradiation. However, some of our cases shows that intramedullary nailing can accelerate tumor spread and metastases elsewhere, so that serious consideration must be given in planning this treatment. In conclusion, the functional status before fracture, life expectancy, type of tumor and extent of involvement should be carefully considered to decide operative treatment of metastatic disease.

• Physical Therapy Korea
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• v.3 no.1
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• pp.57-64
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• 1996

Spinal cord injury in child often occurs without evidence of fracture or dislocation. The mechanisms of neural damage in this syndrome of spinal cord injury without radiographic abnormality(SCIWORA) include flexion, hyperextension, longitudinal distraction, and ischemia. Inherent elasticity of the vertebral column in infants and young children, among other age-related anatomical peculiarities, render the pediatric spine exceedingly vulnerable to deforming forces. The neurological lesions encountered in this syndrome include a high incidence of complete and severe partial cord lesions. Children younger than 8years old sustain more serious neurological damage and suffer a larger number of upper cervical cord lesions than children aged over 8 years. Of the children with SCIWORA. 52% have delayed onset of paralysis up to 4 days after injury, and most of these children recall transient paresthesia, numbness, or subjective paralysis. The long-term prognosis in cases of SCIWORA is grim. Most children with complete and severe lesions do not recover; only those with initially mild neural injuries make satisfactory neurological recovery.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.4
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• pp.317-320
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• 2016

A 47-year-old woman was referred for surgical treatment of osteomyelitis of the mandible. She had already undergone three previous surgeries. Pre-anesthetic airway evaluation predicted a difficult airway, due to the thin, retro-positioned mandible, tongue, and atrophic changes in the lips and soft tissue. We inserted packing gauzes in the buccal mucosa for easier mask fitting and ventilation. During direct laryngoscopic intubation with a nasotracheal tube (NTT), fracture of a thin mandible can easily occur. Therefore, we used a fiberoptic bronchoscope to insert the NTT. After surgery, we performed a tongue-tie to protect against airway obstruction caused by the backward movement of the tongue during recovery. The patient recovered without any complications. We determined the status of the patient precisely and consequently performed thorough preparations for the surgery, allowing the patient to be anesthetized safely and recover after surgery. Careful assessment of the patient and airway prior to surgery is necessary.

• Clinics in Shoulder and Elbow
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• v.1 no.1
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• pp.46-50
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• 1998

The superior shoulder suspensory complex is composed of glenoid fossa, coracoid process, coracoclavicular ligament, distal clavicle, acromioclavicular ligament, acromion. Traumatic double disruptions of this complex lose its suspensory action on the shoulder joint and result in functional loss and deformity. Careful radiologic evaluation and appropriate management are required for injuries to this complex. Ipsilateral fractures of clavicle and scapula create unstable anatomic situation on shoulder joint. Conservative treatment usually fails to achieve good functional recovery due to rotator cuff weakness, nonunion, delayed union, malunion and neurovascular injury. Authors studied the result of operative treatment of ipsilateral clavicle and scapular fractures to prevent such complications. Seven cases were treated with open reduction and internal fixations of clavicle alone or clavicle and scapula simultaneously and followed up for nineteen months(twelve months - thirty-eight months). All but one patient showed good or excellent functional result according to the scoring system of Rowe. Poor result was developed in the case which had brain injury. Rigid fixations of clavicle alone or clavicle and scapular fractures both can achieve stable reduction of the fractures and prevent sequelae. We concluded that operative treatment of ipsilateral fractures of clavicle and scapula is safe and yields predictable good results.

• Journal of Korean Neurosurgical Society
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• v.40 no.6
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• pp.441-444
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• 2006

Objective : The goal of this study is to evaluate the clinical results in six patients who underwent surgical decompression for the acute subdural hematomas[ASDH] of posterior cranial fossa. Methods : Six patients [five males and one female] who had undergone surgery for ASDH of posterior cranial fossa between 2000 and 2005, were evaluated retrospectively with regard to clinicoradiological findings and surgical outcomes. The mean age was 45.8 years [range $9{\sim}67\;years$]. Results : Preoperative computed tomography showed ASDH on cerebellar hemisphere in four patients and on midline in two. All patients had the associated lesions such as subarachnoid hemorrhage, epidural or subdural hematoma, intraventricular hemorrhage, contusion or pneumocephalus in supratentorial area. Fracture of occipital bone was noted in two patients. Of the four patients who had 13 to 15 of Glasgow coma scale score at the time of admission, three were deteriorated within 24 hours after trauma. Of these three patients, delayed subdural hematoma developed 1 hour after initial normal CT finding in one patient and increased in thickness in another one. Postoperative outcome showed good recovery in three patients and moderate disability in one. Two patients were expired. Conclusion : This study supports that early diagnosis based on strict observation and prompt surgery in the patients with ASDH in posterior fossa will lead to the best results.

• Journal of Korean Neurosurgical Society
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• v.52 no.3
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• pp.264-266
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• 2012

Injury to the bilateral internal branch of superior laryngeal nerve (ibSLN) brings on an impairment of the laryngeal cough reflex that could potentially result in aspiration pneumonia and other respiratory illnesses. We describe a patient with traumatic cervical injury who underwent bilateral ibSLN palsy after anterior cervical discectomy with fusion (ACDF). An 75-year-old man visited with cervical spine fracture and he underwent ACDF through a right side approach. During the post-operative days, he complained of high pitched tone defect, and occasional coughing during meals. With a suspicion of SLN injury and for the work up for the cause of aspiration, we performed several studies. According to the study results, he was diagnosed as right SLN and left ibSLN palsy. We managed him for protecting from silent aspiration. Swallowing study was repeated and no evidence of aspiration was found. The patient was discharged with incomplete recovery of a high pitched tone and improved state of neurologic status. The SLN is an important structure; therefore, spine surgeons need to be concerned and be cautious about SLN injury during high cervical neck dissection, especially around the level of C3-C4 and a suspicious condition of a contralateral nerve injury.