• 한국환경농학회지
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• 제21권4호
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• pp.291-296
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• 2002

In this investigation we tried to investigate the effect of oxalic acid on the fate of native sulfate in Bt soil that contained a high kaolinitic clay by observing the distribution of two anions using soil column under the given competitive adsorption between displaced and displacing anions. To do this, the soil columns uniformly packed to a bulk density of 1.25 $g/cm^3$ with Cecil Bt soil were disected and analyzed the amounts of sulfate and oxalic acid both in solution and solid phases after flowing the designated pore volumes of oxalic acid The results showed that two sets of curves-nonlinear (> $10^3M$) and linear (> $10^3M$) curves where the solution of oxalic acid was not adiustet while the approaches to the plateau were slow when pH of oxalic acid was adjusted to 5. The cumulative amount of sulfate desorbed by successive addition of oxalic acid was nonlinearly approached to the plateau at the concentration of $10^3M$ or greater, indicating that the number of addition of oxalic acid increased with decreasing order of oxalic acid. However, the plateau did not obtain where the concentration of oxalic acid were less than $10^4M$, showing a linear increase. Therefore, we may conclude that the rate-limited desorption was involved as the concentration of oxalic acid decreased.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권6호
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• pp.551-553
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• 2004

The displacement of an entire tooth into the adjacent anatomical area is an uncommon complication of a tooth extraction. We encountered a 23-year-old woman who had previously undergone surgery under local anesthesia to remove the lower third molar about 12 weeks prior and the upper third molar was extracted 2 days prior to visiting this hospital. Upon admission, she complained of a swallowing discomfort and a mouth opening limitation. Panoramic radiograph and a CT scan revealed a displacement of the entire tooth into the lateral pharyngeal space. The tooth was retrieved via the transoral approach under general anesthesia. The removed tooth had an indentation formed by a dental bur. Therefore, it was concluded that the tooth displaced into the lateral pharyngeal space was the lower third molar. This report describes an unusual case of a third molar that was displaced into the lateral pharyngeal space with a review of the relevant literature.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.8.1-8.6
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• 2019

Background: Resorbable devices have recently been adopted in the field of orthognathic surgery with controversies about their postoperative skeletal stability. Hence, we determined the long-term skeletal stability of unsintered hydroxyapatite/poly-ʟ-lactic acid (HA/PLLA) mesh for osteofixation of mandibular sagittal split ramus osteotomy (SSRO), and compared it with that of titanium miniplate. Methods: Patients were divided into resorbable mesh and titanium miniplate fixation groups. A comparative study of the change in the mandibular position was performed with preoperative, 1-day, 6-month, and 2-year postoperative lateral cephalograms. Results: At postoperative 6 months-compared with postoperative 1 day, point B (supra-mentale) was significantly displaced anteriorly in the titanium-fixation group. Moreover, at postoperative 2 years-compared with postoperative 6 months, point B was significantly displaced inferiorly in the titanium-fixation. However, the HA/PLLA mesh-fixation group did not show any significant change with respect to point B postoperatively. Conclusions: The HA/PLLA mesh-fixation group demonstrated superior long-term skeletal stability with respect to the position of mandible, when compared with the titanium-fixation group.

• 치과방사선
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• 제18권1호
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• pp.67-73
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• 1988

This study was performed to clarify the mechanism of clicking sound and locking on temporomandibular joint and to determine the radiographic findings of them by using computed tomogram. Through the preliminary study with cadavers, the proper scanning condition and the correlatonship between the anatomy of cadaver and computed tomogram had been determined. The subjects were consisted of 10 controls and 16 patients having clicking sound or locking on temporomandibular joint. By using Hitachi-W500 as computed tomographic device, direct axial views and sagittal views reformed according to the changes in window setting and using the non-linear fraction were taken and analyzed by visual method and measuring the attenuation numbers. The obtained results were as follows: 1. The density of the anterior band of meniscus showed isodense to the surrounding muscles in normal. 2. In patient group, affected side showed increased radiopaque area anterior to condyle and underneath articular eminence as the feature of anteriorly displaced meniscus on axial and sagittal views. 3. In patient group, the condyle was rotated postero-laterally in affected side. 4. Non-linear fraction highlightened the feature of anteriorly displaced meniscus.

• Steel and Composite Structures
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• 제36권3호
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• pp.339-353
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• 2020

This study investigates the seismic performance of steel reinforced concrete (SRC) T-shaped columns under low cyclic loading tests. Based on test results of ten half-scale column specimens, failure patterns, hysteretic behavior, skeleton curves, ultimate strength, ductility, stiffness degradation and energy dissipation capacity were analyzed. The main variables included loading angles, axial compression ratios and steel ratios. The test results show that the average values of the ductility factor and the equivalent viscous damping coefficient with respect to the failure of the columns were 5.23 and 0.373, respectively, reflecting good seismic performance. The ductility decreased and the initial stiffness increased as the axial compression ratio of the columns increased. The strength increased with increasing steel ratio, as expected. The columns displaced along the web had higher strength and initial stiffness, while the columns displaced along the flange had better ductility and energy dissipation capacity. Based on the test and analysis results, a formula is proposed to calculate the effective stiffness of SRC T-shaped columns.

• 한국전자파학회논문지
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• 제20권11호
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• pp.1138-1144
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• 2009

SAR-GMTI는 고해상도 영상과 동시에 차량, 기차와 같은 지상의 이동 표적을 탐지하여 정보를 제공하는 시스템이다. 본 논문에서는 항공기 탑재 측면 관측 영상 레이다에서 지상 이동 표적을 탐지하는 DPCA 기법에 기반하여 지상 이동 표적의 도플러 특성에 따른 영상 내 심각한 위치 오차와 퍼짐 현상을 분석하였다. 그리고 표적의 속도를 거리와 방위 방향으로 나누어 영상에서 위치 오차와 퍼짐 현상을 보상하며, 추정된 표적 속도와 퍼짐의 양을 정량화하여 제안된 보상 기법의 성능을 검증한다.

• Archives of Plastic Surgery
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• 제34권4호
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• pp.524-527
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• 2007

Purpose: Globe displacement due to a blowout fracture is a rare clinical phenomenon. The authors present reduction of a globe displacement to the maxillary sinus due to trauma suffered in a fall and the reconstruction of a large defect left in the medial and inferior orbit. Methods: A 39-year-old male patient was unable to open his left eye after being struck on the periorbital area by a metal edge. Laceration was not noted in that area but we were unable to observe the intraorbital globe. A facial computed tomography (CT) scan showed that the globe was displaced through the maxillary sinus. A transconjunctival approach was used to access the infraorbital margin and the globe entrapped in the inferior margin of the orbit was successfully reduced. A large defect in the medial and inferior orbit was reconstructed using a graft from the iliac bone. Results: In 5 months after the operation, no atrophy of the globe was seen. Both sides retained a similar shape. A satisfactory functionality outcome in terms of improved extraocular muscle movement, and a satisfactory aesthetical outcome were achieved. Conclusion: The authors report the reduction of a globe displaced to the maxillary sinus following a fall and the reconstruction of the large defect left in the medial and inferior orbit.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권3호
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• pp.182-187
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• 2022

Superolateral dislocation of the condyle is a rare mandibular fracture. The treatment goal is to return the dislocated condyle to its original position to recover normal function. This study reports on superolateral dislocation of the condyle with mandibular body fracture. The mandibular body was completely separated, and the medial pole of the condyle head was fractured. The condyle segment was unstable and easily dislocated after reduction. The temporalis muscle on the condyle segment might have affected the dislocation of the condyle. A coronoidectomy was performed to disrupt the function of the temporalis muscle on the condyle segment in order to successfully reduce the dislocated condyle. Coronoidectomy is a simple procedure with minimal complications. We successfully performed a coronoidectomy to reduce the superolateral displaced condyle to its original position to achieve normal function. Coronoidectomy can be effectively used for reduction of superolaterally displaced condyles combined with severe maxilla-mandibular fractures.

• 대한소아치과학회지
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• 제50권1호
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• pp.121-130
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• 2023

소아들에게서 커다란 치성낭은 주위 해부학적 구조물뿐만 아니라 발육 중인 영구치의 변위를 일으키게 되는데 이러한 경우 적출술이나 조대술이 치료법으로 사용되어 진다. 이 증례는 상악에서 발생한 커다란 낭종으로 인해 3개 이상의 영구치와 더불어 상악동 기저부의 거상이 함께 발생한 5세 남자 환자, 10세 남자 환자 2가지 증례를 보고하고 있다. 두 증례 모두에서 합병증을 최소화하기 위해 조대술이 선택되었으며 조대술 후 맹출 유도를 위한 맞춤 제작 아크릴 폐쇄 장치(obturator), 개창술(window opening), 교정적 견인을 점진적으로 시행하여 양호한 예후를 보였기에 이를 보고하는 바이다.

• Journal of Korean Neurosurgical Society
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• 제66권5호
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• pp.598-604
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• 2023

Penetrating head injury is a serious open cranial injury. In civilians, it is often caused by non-missile, low velocity flying objects that penetrate the skull through a weak cranial structure, forming intracranial foreign bodies. The intracranial foreign body can be displaced due to its special quality, shape, and location. In this paper, we report a rare case of right-to-left displacement of an airgun lead bullet after transorbital entry into the skull complicated by posttraumatic epilepsy, as a reminder to colleagues that intracranial metal foreign bodies maybe displaced intraoperatively. In addition, we have found that the presence of intracranial metallic foreign bodies may be a factor for the posttraumatic epilepsy, and their timely removal appears to be beneficial for epilepsy control.