• Composites Research
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• 제17권5호
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• pp.1-6
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• 2004

HDPE (high density polyethlyne) 라이너와 금속 boss를 가진 복합재료 압력용기가 필라멘트 와인딩 공정에 의해 개발되었다. 이 용기의 끝 부위는 dome-shape 부위 그리고 용기의 중앙부는 cylinder-shape로 형성되었다. 용기를 구성하는 재료인 HDPE, 수지 그리고 강화섬유와 같은 용기재료에 대해 환경실험이 1년 이상 실행되었다 Boss 설계는 FEM 해석으로 가스 누출을 최대한 방지해 주는 것으로 확인되었다. 실험적인 방법에 의해 가장 이상적인 fiber tension이 얻어졌고, image analyzer에 의해 측정된 섬유의 체적율, $\textrm{V}_{f}$,는 실린더에서 55.4 %, dome part에서 55.6 % 이었다. Winding pattern은 용기의 파괴가 실린더 부위에서 일어나도록 dome 부위의 복합재료 두께조절을 하도록 프로그램 되었다 경화 중 용기는 돌려졌었고 고정 내부압력 0.62 bar를 가함으로서 최종용기의 파괴압력이 28 % 향상되었다. Under-wound, fully wound된 용기의 파괴 및 피로시험결과를 충족하였다.

• Archives of Plastic Surgery
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• 제33권6호
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• pp.748-752
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• 2006

Purpose:Circular skin lesions between 10 and 35 mm in diameter generate problems often. Direct closure of the lesion risks excessive wound tension or wound dehiscence. Skin grafts heal slowly and often remain unsightly. Traditional skin flaps have a limited role. We treated this circular medium-sized skin lesion(10 - 35 mm sized) by reducing opposed multilobed(ROM) flap. Methods: ROM flap involves a series of semicircular lobes extending both cephalic and caudal from the defect. Direction of the semicircular multilobed flap is set parallel to relaxed skin tension line(RSTL) to minimize scar formation. First semicircle is drawn 60% in diameter of the defect. Second semicircles are drawn at the cephalic and caudal aspects of the original semicircles. These semicircles are 60% in diameter of the first semicircle. Additional semicircles are repeatedly drawn until the tension of skin flaps becomes free. ROM flap has a length-to-base ratio of 0.5 resulting in lower theoretical risk of end flap necrosis than a random pattern flap with a large ratio. The technique involves lobes most distant from the primary defect being transposed in turn closer to the defect. Results: The ROM flap reduces skin tension concerns, lowers the risk of flap necrosis and allows for quicker and more aesthetic healing. Results were generally good and major complications, such as dehiscence, infection, or delayed healing, did not occur. Conclusion: ROM flap repair allows the plastic surgeon an additional option when faced with a circular medium-sized skin lesion.

• Archives of Plastic Surgery
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• 제39권5호
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• pp.463-468
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• 2012

Background In the extremities of premature infants, the skin and subcutaneous tissue are very pliable due to immaturity and have a greater degree of skin laxity and mobility. Thus, we can expect wounds to heal rapidly by wound contraction. This study investigates wound healing of full-thickness defects in premature infant extremities. Methods The study consisted of 13 premature infants who had a total of 14 cases of full-thickness skin defects of the extremities due to extravasation after total parenteral nutrition. The wound was managed with intensive moist dressings with antibiotic and anti-inflammatory agents. After wound closure, moisturization and mild compression were performed. Results Most of the full-thickness defects in the premature infants were closed by wound contraction without granulation tissue formation on the wound bed. The defects resulted in 3 pinpoint scars, 9 linear scars, and 2 round hypertrophic scars. The wounds with less granulation tissue were healed by contraction and resulted in linear scars parallel to the relaxed skin tension line. The wounds with more granulation tissue resulted in round scars. There was mild contracture without functional abnormality in 3 cases with a defect over two thirds of the longitudinal length of the dorsum of the hand or foot. The patients' parents were satisfied with the outcomes in 12 of 14 cases. Conclusions Full-thickness skin defects in premature infants typically heal by wound contraction with minimal granulation tissue and scar formation probably due to excellent skin mobility.

• 대한기계학회논문집A
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• 제21권12호
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• pp.2029-2037
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• 1997

In a web winding process, the contact roll plays many important roles including air-entrainment control and WIT(Wound In Tension) regulation. The behavior of contact roll significantly affects the winding tension characteristics specifically at the time of contact when the speeds of contact roll and the winding roll are not synchronized. A mathematical model for the web, the winding roll, and the contact roll is derived. By using the model derived, a nonlinear PID(NPID) controller is designed to control the winding tension at the time of contact and separation between the contact roll and the winding roll. Computer simulation study showed that the performance of the winding system with the NPID controller significantly improved compared with that of a system with PID controller.

• Archives of Plastic Surgery
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• 제32권1호
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• pp.19-23
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• 2005

Tissue adhesives have gained popularity for quicker and painless closure of lacerations. The use of tissue glue is currently popular for the closure of superficial lacerations, especially in children. Histoacryl $Blue^{(R)}$(2-N-butylcyanoacrylate) is a topical wound closure that precludes the need for foreign bodies to close wounds. The purpose of this study was to compare the applications of Histoacryl $Blue^{(R)}$(HAB) and conventional suture, regarding cosmetic outcome. To compare the short term and long term results of various repair methods, we designed the prospective, randomized, blind study. Patients with laceration undergoing repair were randomly allocated to conventional suture, subcutaneous suture plus HAB, and HAB only groups. The exclusion criterions were large wound that require large tension for repair or avulsion wound. An independent, blinded observer assessed cosmetic result at 7-10 days after repair and 3-9 months postoperatively. Physician's satisfaction with wound appearance was recorded on 100 mm Visual Analogue Scale(VAS)(0=worst, 100=best). The difference in VAS score between conventional suture method and subcutaneous suture plus HAB methods were not significant. Tissue glue being easy to use with no complications and still resulting in equivalent cosmetic outcomes has several benefits. Especially in the case of children, the wound closure with Histoacryl $Blue^{(R)}$ could be a good alternative for repair of laceration in emergency room.

• Journal of Advanced Marine Engineering and Technology
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• 제25권1호
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• pp.87-94
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• 2001

Filament winding process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over a rotating mandrel. And now it is well established as a versatile method for storage tanks and pipe for the chemical and other industries. In this study, tensile strength of a filament wound ring specimens were evaluated by split disk test fixture and dress disk test fixture. The results obtained from experiments were compared with the theoretical values obtained by the rule of mixture. And the purpose of this paper is to suggest an appropriate test method for the evaluation of tensile properties of filament wound structures. The tensile strength of a ring specimens tested by the dress disk test showed better agreement with the theoretical values than of a ring specimen tested by the split disk test because the stress concentration in edges of s split disk test fixture is more severe than the that of dress disk test fixture. The results showed that the tensile strength of a ring specimen was influenced by the geometry of test fixture, the continuity of fibers, fiber-tension, fiber-end and stress concentration in specimen.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 추계학술대회 논문집(Proceeding of the KOSME 2000 Autumn Annual Meeting)
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• pp.15-20
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• 2000

Filament winding process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over a rotating mandrel. And it is now well established as a versatile method for storage tanks and pipe for the chemical and other industries. In this study, tensile strength of a filament wound ring specimens were evaluated by split disk test fixture and dress disk test fixture. The results obtained from experiments were compared with the theoretical values obtained by the rule of mixtures in composites . And the purpose of this paper is the suggestion of an appropriate test method for the evaluation of tensile properties of filament wound structures. The tensile strength of a ring specimen tested by the dress disk test showed better agreement with the theoretical values than that of a ring specimen tested by the split disk test because the stress concentration in edges of a split disk test fixture is more severe than that of dress disk test fixture. The results showed that the tensile strength of a ring specimen was influenced by the geometry of test fixture, the continuity of fibers, fiber-tension, fiber-end and stress concentration in specimen.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.203-207
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• 2000

Filament Winding Process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over a rotating mandrel. And now well established as a versatile method for storage tanks and pipe for the chemical and other industries . In this study, tensile strength of a filament wound ring specimens were evaluated by split disk test fixture and dress disk test fixture , The results obtained from experiments were compared with the theoretical values obtained by the rule of mixtures. And the purpose of this paper is the suggestion of an appropriate test method for the evaluation of tensile properties of filament wound structures .The tensile strength of a ring specimen tested by the dress disk test showed better agreement with the theoretical values than of a ring specimen tested by the split disk test because the stress concentration in edges of a split disk test fixture is more severe than that of dress disk test fixture. The results showed that the tensile strength of a ring specimen was influenced by the geometry of test fixture, the continuity of fibers, fiber-tension, fiber-end and stress concentration in specimen.

• Journal of Yeungnam Medical Science
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• 제36권2호
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• pp.136-140
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• 2019

Background: Epidermal cysts are the most common benign epithelial tumors in humans. The curative treatment of epidermal cyst is surgical excision. However, only few studies have investigated the cause and mechanism of postoperative complications of epidermal cysts. Therefore, this study aimed to evaluate the factors affecting complications of epidermal cyst after surgical treatment. Methods: Patients with histologically diagnosed epidermal cysts were selected from among 98 consecutive patients with excised benign cystic tumors from March 2014 to August 2017. Sex, age, size, mobility, site of occurrence, history of infection, history of incision and drainage, complications, history of reoperation, and method of overcoming complications was obtained by analyzing medical records retrospectively. Results: Five of the 98 patients had wound dehiscence due to surgical infection. Three of them underwent wound healing with conservative treatment without a second operation. The other two patients underwent a second operation and showed signs of preoperative infection. None of the factors showed statistical significance in relation to the occurrence of complications. Conclusion: Postoperative complications occurred when the excision of the epidermal cyst was performed at preoperative infection sites or at sites with high tension, so attention should be paid to postoperative care.

• Archives of Plastic Surgery
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• 제44권4호
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• pp.344-347
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• 2017

Preservation of the breast skin envelope during immediate implant-based breast reconstruction is important for producing symmetrical and natural-looking breasts. We propose the lazy S design for the closure of round-shaped wounds with the hope of improving the aesthetic outcomes and reducing the tension on the wound by preserving the skin. Additionally, the direction of tension is dispersed due to the shape of this design. Patients undergoing implant reconstruction after skin-sparing mastectomy may benefit from the lazy S design.