• International Journal of Aeronautical and Space Sciences
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• 제11권3호
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• pp.227-233
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• 2010

In this study, a genetic algorithm was utilized to optimize the stacking sequence of a composite plate subjected to a high velocity impact. The aim is to minimize the maximum backplane displacement of the plate. In the finite element model, we idealized the impactor using solid elements and modeled the composite plate by shell elements to reduce the analysis time. Various tests were carried out to investigate the effect of parameters in the genetic algorithm such as the type of variables, population size, number of discrete variables, and mutation probability.

• Journal of Trauma and Injury
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• 제31권2호
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• pp.107-111
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• 2018

Segmental bone defects of the tibia present a challenging problem for the orthopedic trauma surgeon. These injuries are often complicated by soft tissue defects and infection. Many techniques are reported, from bone graft to bone transport. To our knowledge, bone transport over the plate in the distraction site has not been described for the treatment of tibial bone defect. We report an instance including procedure and subsequent complications after bone transport over the plate, to restore a tibial bone defect.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권2호
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• pp.131-138
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• 1999

The purpose of this study is to evaluate the effects of resorbable plate in the healing process of mandibular fracture. Reduction and rigid fixation was carried out on the artificial mandibular fracture site of the rabbits, using a resorbable screw, 1.5mm in diameter and 4.0mm in length, and an absorbable plate 1.5mm in thickness(Lactosorb$^{(R)}$). En block tissue specimens with plate were taken from the rabbits at 4, 6, 8, and 10 weeks intervals and specimen were observed with light microscope under the hematoxylin-eosin staining, to observe the inflammatory reaction and tissue healing process. The following conclusions were drawn: 1. The subject displayed good healing with no signs of detachment of the fixation plate. 2. At 4 weeks, the plate was covered by the connective tissue. Then at 6 weeks, bone regeneration was discovered around the plate. 3. During the period of healing, no inflammatory reaction or foreign body reaction, as a result of using resorbable plate, were observed. 4. At 8 weeks, the initial phase of the absorption of the plate was observed. Then at 10 weeks, macrophage were observed around the plate, indicating the absorption phase was in process. From the above results, it can be determined that when the resorbable plate is applied to rabbit, full recuperation occurs naturally in the absence of inflammatory reaction and foreign body reaction. The selected study is clinically valuable in proving this procedure.

• 한국가시화정보학회지
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• 제17권2호
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• pp.58-66
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• 2019

This study investigated heat transfer and flow characteristics of a sweeping jet issued from a rectangular nozzle with a thin plate. A thin vertical aluminum plate was attached on outlet of fluidic oscillator to increase velocity of central area with Coanda effect and enhance heat transfer performance. From visualization and PIV experiments, sweeping jet with a thin plate has larger velocity distribution in center region than that of the normal sweeping jet while oscillating frequency is similar as the normal one. Thermographic phosphor thermometry method was used to visualize the temperature field and Nu distribution of plate with impinging sweeping jet with thin plate. Four Reynolds numbers and three jet-to-wall distances were selected as parameters. It is found that heat transfer performance in the low jet-to-wall spacing was enhanced as the cooled area was expanded. However, when the jet-to-wall spacing became greater than 8dh, heat transfer performance became similar due to reduced impinging velocity.

• 한국주조공학회지
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• 제29권6호
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• pp.265-269
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• 2009

The optimum RRA heat treating conditions and SCC (stress corrosion cracking) resistance of semi-solid Al-Zn-Mg-Cu alloy fabricated by inclined cooling plate were compared with those of conventional mould cast alloys. The non-stirring method characterized by using a cooling plate can effectively eliminate dendritic structure and form a fine globular semisolid microstructure in as-cast Al-Zn-Mg-Cu alloy and the SCC resistance of semi-solid Al-Zn-Mg-Cu alloy was higher than that of conventional mold cast alloy. Also, after retrogressed treatment at RRA heat treatment of semi-solid Al-Zn-Mg-Cu alloy, retrogressed treatment time has increased more than 10 minutes at $180^{\circ}C$ to recovery the T6 heat treatment strength.

• Clinics in Shoulder and Elbow
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• 제20권4호
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• pp.222-229
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• 2017

Background: The purpose of this study was to investigate the outcomes after fixation using a 3.5-mm locking compression plate (LCP) hook plate for isolated greater tuberosity (GT) fractures of the proximal humerus. Methods: We evaluated the postoperative radiological and clinical outcomes in nine patients who were followed up at least 1 year with isolated GT fractures. Using the deltopectoral approach, we fixed the displaced GT fragments with a 3.5-mm LCP hook plate (Synthes, West Chester, PA, USA). Depending on the fracture patterns, the hook plate was fixed with or without augmentation using either tension suture or suture anchor fixation. Results: All the patient showed successful bone union. The mean time-to-union was 11 weeks. The radiological and clinical outcomes at the final follow-up were generally satisfactory. The mean visual analogue scale for pain, the University of California at Los Angeles score, the American Shoulder and Elbow Surgeons score, and the subjective shoulder value were 1.4, 30.3, 84.3, and 82.2%, respectively. The mean active forward flexion, abduction, external rotation, and internal rotation of the shoulder were $156.7^{\circ}$, $152.2^{\circ}$, $61.1^{\circ}$, and the 10th thoracic vertebral level, respectively. Only one patient presented with a postoperative complication of shoulder stiffness. The patient was treated through arthroscopic capsular release on the 5th postoperative month. Conclusions: We conclude that fixation using 3.5-mm LCP hook plates for isolated GT fractures of the proximal humerus is a useful treatment method that provides satisfactory clinical and radiological outcomes.

• 유기물자원화
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• 제25권1호
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• pp.5-13
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• 2017

기존 국내 여과판의 재질은 주로 polypropylene 소재의 여과판을 사용하였으며 그 이유는 성형성이 좋고, 가격이 저렴하며 매우 보편적으로 보급된 소재이기 때문이다. 그러나 고압에 의해 한번 뒤틀려진 polypropylene 소재 여과판은 재사용이 어려우며 가압형 고액분리모듈의 연속 운전에 문제를 야기할 수 있다. 따라서 기존 polypropylene 소재보다 성능이 뛰어난 TPU(Thermoplastic Poly Urethane) 소재개발을 위해 새로운 소재에 대해 설계된 여과판의 구조적 안정성을 해석적 기법을 통해 예측하였다. 20 bar의 압력하중 하에서 TPU를 적용한 여과판은 최대 변형량이 27.85 MPa로 나타났으며 이 값은 TPU 응력-변형률(Stress-Strain) 한계치 이하 값으로 여과판 재질에 대한 구조적 안정성을 확보하였다.

• 한국정밀공학회지
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• 제19권8호
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• pp.180-186
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• 2002

Hot Plate is the major unit that it used to remove damp of wafer surface, to strength adhesion of photoresist (PR) and to bake coated PR in FAB process of semiconductor. The badness of Hot Plate (HP) has directly influence upon the performance of wafer, it is necessary to guarantee the performance of HP. In this study, a reliability evaluation system has been designed and developed, which is to measure and to estimate thermal uniformity and flatness of HP in range of temperature 0~$250^\circC$. This system has included the techniques which measures and analyzes thermal uniformity using infrared thermal vision, and which compensates measuring error of flatness using laser displacement sensor For measuring flatness, a measurement stage of 3 axes are developed which adapts the precision encoder. The allowable error of this system in respect of thermal uniformity is less $than\pm0.1^\circC$ and in respect of flatness is less $than\pm$1mm . It is expected that the developed system can measure from $\Phi200mm\;(wafer 8＂)\;to\;\Phi300mm$ (wafer 12＂) and also can be used in performance test of the Cool Plate and industrial heater, etc.

• Journal of Radiation Protection and Research
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• 제42권3호
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• pp.141-145
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• 2017

Background: The concrete walls inside the vaults of cyclotron facilities are activated by neutrons emitted by the targets during radioisotope production. Reducing the amount of radioactive waste created in such facilities is very important in case they are decommissioned. Thus, we proposed a strategy of reducing the neutron activation of the concrete walls in cyclotrons during operation. Materials and Methods: A polyethylene plate and B-doped Al sheet (30 wt% of B and 2.5 mm in thickness) were placed in front of the wall in the cyclotron room of a radioisotope production facility for pharmaceutical use. The target was Xe gas, and a Cu block was utilized for proton dumping. The irradiation time, proton energy, and beam current were 8 hours, 30 MeV, and $125{\mu}A$, respectively. To determine a suitable thickness for the polyethylene plate set in front of the B-doped Al sheet, the neutron-reducing effects achieved by inserting such sheets at several depths within polyethylene plate stacks were evaluated. The neutron fluence was monitored using an activation detector and 20-g on de Au foil samples with and without 0.5-mm-thick Cd foil. Each Au foil sample was pasted onto the center of a polyethylene plate and B-doped Al sheet, and the absolute activity of one Au foil sample was measured as a standard using a Ge detector. The resulting relative activities were obtained by calculating the ratio of the photostimulated luminescence of each foil sample to that of the standard Au foil. Results and Discussion: When the combination of a 4-cm-thick polyethylene plate and B-doped Al sheet was employed, the thermal neutron rate was reduced by 78%. Conclusion: The combination of a 4-cm-thick polyethylene plate and B-doped Al sheet effectively reduced the neutron activation of the investigated concrete wall.

• Journal of Ceramic Processing Research
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• 제13권spc2호
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• pp.270-273
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• 2012

x mol% (x = 0 ~ 20) Na2CO3 excess Bi2.5Na3.5Nb5O18 (BNN) particles were synthesized using molten salt as a flux. The secondary phases were observed at stoichiometric ratio of BNN precursors and their intensity decreased with increasing Na contents. The results of SEM images showed that all particles existed in a platelet shape and the particle increased in size with higher increasing Na contents. Plate-like NaNbO3 particles were developed using BNN precursor obtained by a topochemical microcrystal conversion. XRD analysis of NaNbO3 particles showed that a single perovskite phase and the intensity of (h00) peaks increased with increasing Na contents in BNN precursor. SEM images showed that the size of plate-like NaNbO3 was significantly changed by controlling Na contents in BNN precursors.