• Title/Summary/Keyword: composite defect

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Tendocutaneous Free Flap Transfer from Dorsum of the Foot (족배부 유리편을 이용한 생건 피부편이식)

  • Lee, Kwang-Suk;Park, Sang-Won;Byun, Young-Soo;Kang, Ki-Hoon;Kang, Oh-Yong
    • Archives of Reconstructive Microsurgery
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    • v.1 no.1
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    • pp.24-30
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    • 1992
  • Tendocutaneous free flap transfer has been usually used to treat troublesome wounds, which had extensive defect of skin and tendons, since Daniel and Taylor had reported successful free flap transfer in 1973. Among the numerous types of free flap, the dorsalis pedis flap, which could include superficial peroneal nerve, extensor tendon and second metatarsus, was widely used as composite free flap. The authors analysed 13 cases of tendocutaneous free flap transfer from dorsum of the foot which were operated at Korea University Hospital from March 1981 to August 1991. The results were as follows: 1. The average size of these flaps was $53.7cm^2$(mazimum $82cm^2$, minimum $30cm^2)$, the average number and length of tendons were 2.9(maximum, 5, minimum 1), and 9.2cm (maximum 17cm, minimum 5cm). 2. The survival rate of flaps was 100%, and functional results by Dargan's criteria were 4 in excellent, 4 good, 3 fair and 2 poor. 3. The delayed healing on donor site could prevented by the meticulous skin graft and repair of extensor retinaculum. 4. The cases of electrical burn were more worse than the traumatic cases in functional results.

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A Study of the Formation of Binary Intermediate Layer on Pd-based Hydrogen Separation Membrane Using Various Types of Metal Oxides (다양한 형태의 금속 산화물을 이용한 Pd계 복합 수소분리막의 2원계 중간층 형성에 관한 연구)

  • Hwang, In-Hyuck;Kim, Sung Su
    • Applied Chemistry for Engineering
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    • v.29 no.2
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    • pp.196-200
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    • 2018
  • In this study, the intermediate layer in Pd-based hydrogen separation membrane was synthesized to minimize the surface roughness and defects using powder-type and sol-type metal oxides. The surface properties and gas permeation characteristics were analysed by SEM and $N_2$ gas permeation test. The coating layer composed of sol type metal oxides has smooth surface, especially the layer coated by $TiO_2$ sol has little pin holes, cracks and defects. The binary layer composed of powder type and sol type metal oxides has similar flux characteristics to a single sol type layer. The Pd-based composite membrane improved by the binary intermediate layer exhibited $0.32mol/m^2s$ of the hydrogen permeation flux with a selectivity ($H_2/N_2$) of ~10,890 at 672 K and a pressure difference of 1 bar.

Evaluation of Dispersivity and Resistance of the Adhesive Joint According to Dispersion Methods of CNT (CNT 분산 방법에 따른 접착조인트의 저항 및 분산성 평가)

  • Lee, Bong-Nam;Kim, Cheol-Hwan;Kweon, Jin-Hwe;Choi, Jin-Ho
    • Composites Research
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    • v.28 no.6
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    • pp.348-355
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    • 2015
  • NDT (Non Destructive Test) of the adhesive joints is very important because their strengths have greatly affected by the worker's skill and environmental condition. Recently, the electric impedance method in which 1-2 wt% CNT was dispersed in the adhesive and the electric resistance of the adhesive joint was measured was suggested for the defect detection of the adhesive joint. The uniform dispersion of CNT in the electric impedance method is very important to make a constant electric resistance of the adhesive joint and the accuracy of defect detection depends on the uniform dispersion. In this paper, the adhesive joints in which CNT was dispersed in the adhesive by the four dispersion methods were made and their electric resistance were measured. The pre-process and evaporation process of CNT using the ultrasonic method and agitation method was used and the effective dispersion method was suggested. Also, the criteria to evaluate the dispersivity was proposed.

RECONSTRUCTION OF MANDIBULAR DEFECT WITH COMPOSIITE AUTOGENOUS ILIAC BONE AND COSTOCHONDRAL GRAFTS (자가장골 및 늑연골의 복합이식을 통한 하악골 재건술)

  • Chang, Se-Hong;Ann, Jye-Jynn;Soh, Jae-Jung;Park, Chi-Hee
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.13 no.1
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    • pp.104-109
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    • 1991
  • Loss of mandibular continuity due to neoplasm, trauma, or infection results in major esthetic and biologic compromise. The use of costochondral grafts for reconstruction of temporomandibular joint, described first by Gillies in 1920, has been accepted as a suitable method for replacing the mandibular condyle, especially in growing children. Autogenous iliac bone graft has been a satisfactory source of mandibular reconstruction since Sykoffs report in 1900. Autogenous bone grafts from the posterior aspects of the ilium provide large amount of PMCB with acceptable donor site morbidity. In timing of reconstruction, initial disease, age, medical history, growth and development, esthetic and psychologic factors should be considered. We present a case of osteosarcoma in the mandible that was treated by a hemimandibulectomy and the defect was reconstructed 20 months later with composite method of costochondral and posterior iliac bone graft.

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Reconstruction of hand using anterolateral thigh fascial free flap (전외측대퇴근막 유리피판술을 이용한 수부의 재건)

  • Kim, Ki Wan;Kim, Jin Soo;Lee, Dong Chul;Ki, Sae Hwi;Roh, Si Young;Yang, Jae Won
    • Archives of Plastic Surgery
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    • v.36 no.5
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    • pp.571-577
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    • 2009
  • Purpose: The Provision of thin and pliable tissue and the adequate coverage of tendon - gliding surface is necessary for a soft tissue defect of the hand with exposure of bone, tendon and muscle. This report will discuss our experience with anterolateral thigh fascial free flap for the reconstruction of the soft tissue defect of the hand. Methods: Between February 2004 and August 2008, seven patients with full - thickness soft tissue defects of the hand were reconstructed by means of a composite anterolateral thigh fascial free flap. There were soft tissue defects associated with trauma (n=5), scar contracture (n=1) and necrosis due to ischemia (n=1). Flaps were harvested from the anterolateral thigh as adipofascial flaps with only a small sheet of fascia and fatty tissue above it. The fascia and the skin of the donor site was closed directly and delayed split - thickness skin graft was performed. Result: All flaps survived completely. The size of the transferred flap ranged from $2{\times}4cm$ to $5{\times}8cm$. Thin flap coverage was possible without secondary debulking operations. It left minimal donor site morbidity with a linear scar. In one case, the thigh muscle herniation in the donor site was developed. Conclusion: The anterolateral thigh fascial free flap provided thin and pliable tissue which can establish a tendon - gliding mechanism, minimal bulk, minimal donor site morbidity. The disadvantages of this technique were the need for a skin graft and the muscle herniation of donor site.

Influence of vacancy defects on vibration analysis of graphene sheets applying isogeometric method: Molecular and continuum approaches

  • Tahouneh, Vahid;Naei, Mohammad Hasan;Mashhadi, Mahmoud Mosavi
    • Steel and Composite Structures
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    • v.34 no.2
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    • pp.261-277
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    • 2020
  • The main objective of this research paper is to consider vibration analysis of vacancy defected graphene sheet as a nonisotropic structure via molecular dynamic and continuum approaches. The influence of structural defects on the vibration of graphene sheets is considered by applying the mechanical properties of defected graphene sheets. Molecular dynamic simulations have been performed to estimate the mechanical properties of graphene as a nonisotropic structure with single- and double- vacancy defects using open source well-known software i.e., large-scale atomic/molecular massively parallel simulator (LAMMPS). The interactions between the carbon atoms are modelled using Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) potential. An isogeometric analysis (IGA) based upon non-uniform rational B-spline (NURBS) is employed for approximation of single-layered graphene sheets deflection field and the governing equations are derived using nonlocal elasticity theory. The dependence of small-scale effects, chirality and different defect types on vibrational characteristic of graphene sheets is investigated in this comprehensive research work. In addition, numerical results are validated and compared with those achieved using other analysis, where an excellent agreement is found. The interesting results indicate that increasing the number of missing atoms can lead to decrease the natural frequencies of graphene sheets. It is seen that the degree of the detrimental effects differ with defect type. The Young's and shear modulus of the graphene with SV defects are much smaller than graphene with DV defects. It is also observed that Single Vacancy (SV) clusters cause more reduction in the natural frequencies of SLGS than Double Vacancy (DV) clusters. The effectiveness and the accuracy of the present IGA approach have been demonstrated and it is shown that the IGA is efficient, robust and accurate in terms of nanoplate problems.

Upper eyelid reconstruction using a combination of a nasal septal chondromucosal graft and a Fricke flap: a case report

  • Lee, Ju Ho;Woo, Sang Seok;Shin, Se Ho;Kim, Hyeon Jo;Kim, Jae Hyun;Kim, Seong Hwan;Suh, In Suck
    • Archives of Craniofacial Surgery
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    • v.22 no.4
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    • pp.204-208
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    • 2021
  • Sebaceous carcinoma is a malignant neoplasm that usually arises in the sebaceous glands of the eyelids. Its pathogenesis is unknown; however, irradiation history, immunosuppression, and use of diuretics are known risk factors. The mainstay of treatment for sebaceous carcinoma of the eyelid is wide surgical resection with a safety margin of 5 to 6 mm, which often results in full-thickness defects. The reconstruction of a full-thickness defect of the eyelid should be approached using a three-lamella method: a mucosal component replacing the conjunctiva, a cartilage component for the tarsal plate, and a flap or skin graft for the skin of the eyelid. In this case, a full-thickness defect of the upper eyelid was reconstructed after tumor removal using a combination of a nasal septum chondromucosal composite graft and a forehead transposition flap, also known as a "Fricke flap." The flap was designed to include a line of the eyebrow on the lower margin of the flap to replace the eyelash removed during tumor excision. The wound healed completely, without any early or late complications, and the outcome was satisfactory.

Development of Composite Flours and Their Products Utilizing Domestic Raw Materials IV. Textural Characteristics of Noodles made of Composite Flours Based on Barley and Sweet Potato (국산원료(國産原料)를 활용한 복합분(複合粉) 및 제품개발(製品開發)에 관한 연구(硏究) 제4보 보리 및 고구마복합분(複合粉)을 이용한 면류(麵類)의 Texture 특성(特性))

  • Chang, Kyung-Jung;Lee, Su-Rae
    • Korean Journal of Food Science and Technology
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    • v.6 no.2
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    • pp.65-69
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    • 1974
  • Noodles were made from composite flours based on barley or sweet potato/wheat flour and their quality was assessed to obtain the following results. 1) In noodle sheet and dried noodle formation, barley flour could substitute 100% and sweet potato flour, 70% of wheat flour and their textural characteristics were improved by addition of glyceryl monostearate and sodium polycrylate. 2) Textural parameters such as hardness, cohesiveness and gumminess of noodle sheet and dried noodle were decreased by admixture of barley of sweet potato flour whereas they were increased by use of the additives. Noodle sheet required hardness over 6.2 and gumminess over 430 while dried noodle needed hardness over 6.8. 3) In cooked noodle, replacement of wheat flour and use of additives tended to lower the textural parameters. With respect to the cooking quality, barley flour could substitute 60% and sweet potato flour, 40% of wheat flour. 4) In organoleptic evaluation of cooked noodle with respect to its color, taste and texture, 20% replaced composite flour was not different significantly at 5% level from wheat flour and the quality defect was mainly due to discoloration of the product.

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Failure Characteristics of Scarf Patch-repaired Composite Single-lap Joints (스카프 패치로 수리한 복합재 단일겹침 체결부의 파손 특성 연구)

  • Kim, Choong-Hyun;Yoo, Jae-Seung;Byeon, Chang-Seok;Ju, Hyun-Woo;Park, Min-Young;Choi, Jin-Ho;Kweon, Jin-Hwe
    • Composites Research
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    • v.29 no.3
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    • pp.117-124
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    • 2016
  • The failure strength of composite single-lap joint repaired using scarf patch was investigated by test and finite element method. A total of 45 specimens were tested changing scarf ratio, stacking pattern, and defect size to study the failure strength and mode. Except for one case, all repaired specimens showed the equal or higher strength than the sound specimens and the effect of considered repair parameters was not remarkable. It was found through the failure mode inspection that the surface treatment for bonding was not enough in the case which failed at the lower load than the sound specimen. Three-dimensional finite element analysis was conducted to verify the test results. It was confirmed that the considered repair parameters do not significantly affect the stress distribution of the specimens. It was also observed that the applied tensile load is relieved passing through the overlapped region thickness of which is almost double. From this study, it is concluded that if the bonding procedure for adherends and patch including surface treatment for fabric layer is thoroughly followed, the strength of repaired single-lap joint can be restored up to the strength of sound one.

In Vitro and In Vivo Evaluation of Composite Scaffold of BCP, Bioglass and Gelatin for Bone Tissue Engineering

  • Kim, Woo Seok;Nath, Subrata Deb;Bae, Jun Sang;Padalhin, Andrew;Kim, Boram;Song, Myeong Jin;Min, Young Ki
    • Korean Journal of Materials Research
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    • v.24 no.6
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    • pp.310-318
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    • 2014
  • In this experiment, a highly porous scaffold of biphasic calcium phosphate (BCP) was prepared using the spongereplica method. The BCP scaffold was coated with 58S bioactive glass (BG) and sintered for a second time. The resulting scaffold was coated with gelatin (Gel) and cross-linked with [3-(3-dimethyl aminopropyl) carbodiimide] and N-Hydroxysuccinamide (EDC-NHS). The initial average pore size of the scaffold ranged from 300 to $700{\mu}m$, with more than 85 % porosity. The coating of BG and Gel had a significant effect on the scaffold-pore size, decreasing scaffold porosity while increasing mechanical strength. The material and surface properties were evaluated by means of several experiments involving scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). Cytotoxicity was evaluated using MTT assay and confocal imaging of MC3T3-E1 pre-osteoblast cells cultured in vitro. Three types of scaffold (BCP, BCP-BG and BCP-BG-Gel) were implanted in a rat skull for in vivo evaluation. After 8 weeks of implantation, bone regeneration occurred in all three types of sample. Interestingly, regeneration was found to be greater (geometrically and physiologically) for neat BCP scaffolds than for two other kinds of composite scaffolds. However, the other two types of scaffolds were still better than the control (i.e., defect without treatment).