• Title/Summary/Keyword: composite defect

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Immediate Reconstruction of Defects Developed After Treatment of Head and Neck Tumors Using Cutaneous and Composite Flaps (두경부종양 치료 후 발생한 결손의 피판 및 복합조직이식을 이용한 재건)

  • Tark, Kwan-Chul;Lee, Young-Ho;Lew, Jae-Duk
    • Korean Journal of Head & Neck Oncology
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    • v.1 no.1
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    • pp.35-61
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    • 1985
  • The surgical treatment of advanced carcinomas and some benign tumors having clinically malignant behaviors of the head and neck region often require extensive resection, necessitating large flaps for reconstruction. Since the original upper arm flap was described by Tagliacozzi in 1597, a variety of technique such as random pattern local flap, axial flap, distant flap, scalping flap, myocutaneous flap, free flap etc. have been proposed for reconstruction of head, face and neck defects. Reconstruction of the facial defects usually require the use of distant tissue. Traditionally, nasal reconstruction has been carried out with a variety of forehead flaps. In recent years, there has been more acceptance of immediate repairs following the removal of these tumors. As a result, patients are more willing to undergo these extensive resections to improve their chances of cure, with the reasonable expectation that an immediate reconstruction will provide an adequate cosmetic result. Authors experienced 13 cases of head and neck tumor during last three and half years that required wide excision and immediate reconstruction with various flaps, not with primary closure or simple skin graft. We present our experience with varied flaps for reconstruction after wide resection of head and neck tumors 3 cases of defect of dorsum of nose or medial canthus with island forehead flaps, lower eyelid defect with cheek flap, cheek defect with Limberg flap, orbital floor defect with Temporalis muscle flap, lateral neck defects with Pectoralis major myocutaneous flap or Latissimus dorsi myocutaneous free flap, subtotal nose defect with scalping flap, wide forehead defect with Dorsalis pedis free flap and 3 cases of mandibular defect or mandibular defect combined with lower lip defect were reconstructed with free vascularized iliac bone graft or free vascularized iliac bone graft concomitantly combined with free groin flap pedicled on deep circumflex iliac vessels We obtained satisfactory results coincided wi th goal of treatment of head and neck tumors, MAXIMAL CURE RATE with MINIMAL MORBIDITY, OPTIMAL FUNCTION, and an APPEARANCE as close to normal as possible.

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Analysis of Defect Signals Inside Glass Fiber Reinforced Polymer Through Deconvolution of Terahertz Wave (테라헤르츠파의 디컨벌루션을 통한 유리섬유 복합재 내부 결함 신호 분석)

  • Kim, Heon-Su;Park, Dong-Woon;Kim, Sang-Il;Lee, Jong-Min;Kim, Hak-Sung
    • Composites Research
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    • v.35 no.1
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    • pp.8-12
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    • 2022
  • Analysis of defect signals inside glass fiber reinforced polymer (GFRP) was conducted through deconvolution of terahertz (THz) wave. The GFRP specimen with internal defects was manufactured and the THz signal was measured through the reflection mode of the Terahertz Time-Domain Spectroscopy (THz-TDS) system. For deconvolution of the measured THz signal, the peak position of the THz signal was amplified through Normalized Cross Correlation (NCC) of the incident and detected THz signals. The position and intensity of the amplified peak were extracted as impulse, and the extracted signal of the impulse position was removed from the THz original signal. By repeating the process, the critical impulses, which represent boundary of the specimen, were derived. The deconvolution process was verified by confirming that the original THz signal without noise can be restored through the convolution of the critical impulses and the incident signal. From the derived critical impulses, the thickness of the internal defect in the GFRP was calculated through the detection time of impulses within 15 ㎛ accuracy.

Various Methods of Reconstruction in Nasal Defect (코 결손 부위에 따른 다양한 재건)

  • Kim, Seok Kwun;Yang, Jin Il;Kwon, Yong Seok;Lee, Keun Cheol
    • Archives of Craniofacial Surgery
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    • v.11 no.1
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    • pp.13-18
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    • 2010
  • Purpose: Nasal defect can be caused by excision of tumor, trauma, inflammation from foreign body reaction. Nose is located in the middle of face and protruded, reconstruction should be done in harmony with size, shape, color, and textures. We report various methods of nasal reconstruction using local flaps. Methods: From March 1998 to July 2008, 36 patients were operated to reconstruct the nasal defects. Causes of the nasal defects were tumor (18 cases), trauma (11 cases), inflammation from foreign body reaction (5 cases) and congenital malformation (2 cases). The sites of the defects were ala (22 cases), nasal tip (8 cases) and dorsum (6 cases). The thickness of the defects was skin only (5 cases), dermis and cartilagenous layer (7 cases) and full-thickness (24 cases). According to the sites and thickness of the defects, various local flaps were used. Most of alar defects were covered by nasolabial flaps or bilobed flaps and the majority of dorsal and tip defects were covered by paramedian forehead flaps. Small defects below $0.25 cm^2$ were covered with composite graft or full-thickness skin graft. Results: The follow-up period was 14 months. Partial flap necrosis was observed in a case, and one case of infection was reported, it was improved by wound revision and antibiotics. Nasal reconstruction with various local flaps could provide satisfactory results in terms of color and texture match. Conclusion: The important factors of nasal reconstruction are the shape of reconstructed nose, color, and texture. Nasolabial flap is appropriate method for alar or columellar reconstruction and nasolabial island flap is suitable for tip defect. The defect located lateral wall could be reconstructed with bilobed flap for natural color and texture. Skin graft should be considered when the defect could not afford to be covered by adjacent local flap. And entire nasal defect or large defect could be reconstructed by paramedian forehead flap.

Characterization of Resistive Switching in PVP GQD / HfOx Memristive Devices (PVP GQD / HfOx 구조를 갖는 전도성 필라멘트 기반의 저항성 스위칭 소자 특성)

  • Hwang, Sung Won
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.1
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    • pp.113-117
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    • 2021
  • A composite active layer was designed based on graphene quantum dots, which is a low-dimensional structure, and a heterogeneous active layer of graphene quantum dots was applied to the interfacial defect structure to overcome the limitations. Increasing to 1.5~3.5 wt % PVP GQD, Vf changed from 2.16 ~ 2.72 V. When negative deflection is applied to the lower electrode, electrons travel through the HfOx/ITO interface. The Al + ions are reduced and the device dominates at low resistance. In addition, as the PVP GQD concentration increased, the depth of the interfacial defect decreased, and the repetition of appropriate electrical properties was confirmed through Al and HfOx/ITO. The low interfacial defects help electrophoresis of Al+ ions to the PVP GQD layer and the HfOx thin film. A local electric field increase occurred, resulting in the breakage of the conductive filament in the defect.

A Study on the Improvement Buckling Strength of Laminated Composite Plate by Taguchi Method (다구찌법을 이용한 복합적층판의 좌굴강도 개선에 관한 연구)

  • 구경민;홍도관;김동영;박일수;안찬우;한근조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1362-1365
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    • 2003
  • On this study. we improved the efficiency applying algorithm that is repeatedly using orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized buckling strength of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result optimization achievement repeatedly using statistical orthogonal array of experimental design.

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Optimal Ply Design of Laminated Composite Cantilever plate Considering Vibration (진동을 고려한 복합적층 외팔평판의 최적적층설계)

  • Gu, K.M.;Noh, Y.H.;Kim, D.Y.;Hong, D.K.;Ahn, C.W.;Han, G.J.;Park, H.S.
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1660-1665
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    • 2003
  • On this study, we improved the efficiency applying algorithm that is repeatedly using orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized 1st natural frequency of CFRP laminated composite cantilever plate by each aspect ratio. A finite element analysis on the CFRP laminated composite cantilever plate using orthogonal array is carried out, and the results are compared with those obtained by modal testing.

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Optimal Ply Design of Laminated Composite Plate with a Hole Considering Vibration (진동을 고려한 원공복합적층판의 최적적층설계)

  • 홍도관;김동영;최경호;안찬우
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.6
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    • pp.423-429
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    • 2003
  • On this study. we improved the efficiency applying algorithm that is repeatedly using table of orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized 1st natural frequency of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result of optimization achievement repeatedly using statistical table of orthogonal array of experimental design and the BFGS optimal design method.

Biodegradable Hydroxyapatite/Chitosan Composites on the Bone Defect of Canine Model

  • Kim, Jooho;Lee, Dongbin;Heo, Suyoung;Kim, Namsoo
    • Journal of Veterinary Clinics
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    • v.34 no.6
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    • pp.410-413
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    • 2017
  • Composites of hydroxyapatite (HAp) and chitosan (CS) have been successfully used in bone healing in humans and animals. However, the characteristics of HAp and CS are different. Therefore, the effects of HAp/CS composites on canine bone formation could differ according to their ratio. This study investigated the therapeutic effects of different contents ratios (100, 80:20, 60:40 wt%) on bone defects in a canine model. Thirty intrabony cylindrical defects were created in the humeruses and femurs of 5 beagle dogs, and then the defects were implanted with different composites. The evaluations were performed using radiographs obtained at 10 weeks post-surgery and by histological findings. In radiographic evaluation including the grades of bone filling, periosteal and endosteal reactions, pure hydroxyapatite composite had a significant effect on bone filling, and chitosan containing the composites showed vigorous responses at the periosteum and endosteum. In histological findings, the defect implanted with pure hydroxyapatite had healed completely into mature bony tissue with an obvious osteon structure, and the defect implanted with chitosan containing the composites had the amount of fibrous connective tissue increased significantly within the cortical bone tissue. The results indicate that hydroxyapatite/chitosan composites are therapeutically useful, promoting effective bone healing in defects when the ratio of hydroxyapatite is high and enhanced fibrous connective tissue formation at the periosteum as more chitosan is added.