• 한국해양공학회지
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• 제30권5호
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• pp.349-355
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• 2016

Divinycell, which functions as both insulation and a supporting structure, is generally applied in the NO96-type liquefied natural gas (LNG) insulation system. Polymer-material-based Divinycell, which has a high strength and low weight, has been widely used in the offshore, transportation, wind power generation, and civil engineering fields. In particular, this type of material receives attention as an insulation material because its thermal conductivity can be lowered depending on the ambient temperature. However, it is difficult to obtain research results for Divinycell, even though the component materials of the NO96-type LNG cargo containment system, such as 36% nickel steel (invar steel), plywood, perlite, and glass wool, have been extensively studied and reported. In the present study, temperature and strain-rate dependent compressive tests on Divinycell were performed. Both the quantitative experimental data and elastic recovery are discussed. Finally, the mechanical characteristics of Divinycell were compared to the results of polyurethane foam insulation material.

• 대한토목학회논문집
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• 제44권2호
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• pp.133-139
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• 2024

본 연구는 현재 내진 구조 분야에서 압축부재로 사용되고 있는 폴리우레탄의 한계를 극복하기 위해 폴리케톤이라는 신소재 제안을 목적으로 한다. 기존 폴리우레탄은 우수한 탄성 특성을 지녔음에도 불구하고 구조물에 발생하는 변위를 회복하기에는 부족한 경향이 있다. 반면, 폴리케톤은 뛰어난 강도 성능을 보유함과 동시에 친환경 소재로 주목받고 있다. 이러한 장점을 가진 폴리케톤의 압축특성 평가를 위하여 기존에 사용되고 있던 폴리우레탄과의 비교실험을 진행하고자 한다. 단순압축실험과 반복 하중 조건에서의 실험 속도 변화를 통해 폴리케톤의 속도 의존성을 파악하고, 추가적으로 선행압축을 적용하여 압축거동 특성을 확인하였다. 폴리케톤은 폴리우레탄에 비하여 약 10배가량 높은 압축강도를 나타내었으며 비교적 작은 변위에서는 14배가량 높은 변형 회복능력으로 폴리케톤의 우수한 회복특성을 입증하였다.

• 복식문화연구
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• 제19권2호
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• pp.334-345
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• 2011

A study on compressive garments guarantee the required pressure and form depending on the type of disease and the state of injury can be used in the preventive treatment of cardiovascular disease. This research is to provide a preliminary data to develop medical clothing products, especially knitted compression garments. Starting from analyzing knitted structure of imported pressure goods to apply to test samples, 11 kinds of knitted stretchy fabrics were manufactured under the various knitting conditions, then their tensile, mechanical and hand properties were measured. In comparison size changes by knitting structure, tuck stitch applied structure showed an increase in course direction and decrease in wale direction. Float stitch applied structure indicated the contraction of size in width because of unformed loops and floated yarn on the technical back of fabric. As a result of tensile properties in tuck and float applied structure, tensile strength was increased in the course direction. On the other hand, the more loops overlapped due to the tuck and float stitch, the more decreased their elongation and elastic recovery were. In case of mechanical properties, as the tuck and float stitch were overlapped double or triple the bending and shearing properties were risen. Accordingly, the drape of fabric becomes stiff, and its surface becomes rough and uneven. The measurements of hand properties showed that the value of KOSHI, FUKURAMI NUMERI in tuck and float applied structure are higher than the plain structure. This results from the relationship between the mechanical and hand properties.

• 대한기계학회논문집A
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• 제41권2호
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• pp.157-164
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• 2017

패러럴 슬라이드 게이트밸브는 복합발전플랜트 배열회수보일러와 증기터빈 사이에 위치하여 증기유동의 흐름을 제어하는 밸브로서 운전기간 동안 기동, 부하변동 및 정지 등의 운전이 반복적으로 이루어진다. 따라서, 각 기동운전 중에 밸브 두께 방향의 온도 차이로 인하여 발생하는 큰 압축 열응력으로 인한 피로손상 및 구조건전성에 대한 평가가 필요하다. 본 논문에서는 배열회수보일러의 주중기 밸브로 설치되는 16인치 패러럴 슬라이드 게이트밸브의 피로수명 평가를 위한 열구조해석 및 ASME B&PVC VIII-2에서 제시된 탄성응력해석 및 등가응력에 기반한 피로수명 평가를 수행하였다.

• 지질공학
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• 제33권4호
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• pp.599-609
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• 2023

국내 항만 방파제의 내진보강시 현장여건, 현장상황 등으로 회수율이 불확실한 경우가 많아 문제점이 지속적으로 발생하고 있다. 따라서, 본 연구에서는 저유동성 몰탈주입 공법 적용 후 그라우팅 확인방법으로 시추조사를 통한 회수율 및 개량체의 압축강도를 분석하였으며, 추가적으로 다운홀 테스트 및 토모그래피로 탄성계수를 확인하여 지반개량 후 연약지반의 보강 증대 효과를 확인하고자 하였다. 실험결과, 다운홀테스트의 경우 BH-1번과 3번공에서 심도 28.0 m까지에 대한 지반의 평균 전단파속도는 229 m/s에서 288 m/s로 증가하였고, 심도 30.0 m까지에 대한 지반의 평균 전단파속도는 224 m/s에서 282 m/s로 증가하는 경향을 보였다. 이는 보강후 지반의 강성이 증대되어 나타난 결과로 판단된다. 토모그래피 탐사 결과, Site1번의 시료의 연약지반의 Vs가 113 m/s에서 214 m/s, Site2번 시료의 Vs는 120 m/s에서 224 m/s로 증가하였다. 이는 전단파속도에 따른 암질의 분류에서 Vs값이 180~360 m/s를 만족하는 값으로 내진보강 후의 지반의 강성이 단단한 흙으로 보강됨을 확인할 수 있다.

• Archives of Plastic Surgery
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• 제36권4호
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• pp.512-515
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• 2009

Purpose: Neurofibromatosis(NF) is an autosomal - dominant systemic disease. Up to fifty percent of patients with NF are reported to have concomitant vascular abnormalities. In the resection of a larger NF, the risk of uncontrolled hemorrhage is much higher due to the difficulty of hemostasis of large vessels within the tumor. We ligated the base of the giant NF with a simple loop - shaped ligation before removal of the giant NF in both buttocks. And then we could successfully reduce the amount of hemorrhage during the operation. Methods: A 46 - year - old female patient presented for giant masses of both gluteal area, which has been growing slowly for the last ten years. Each mass was about $30{\times}20cm$ in size. After designing the elliptical resection margin, we tightened the tumor base by using continuous loop - shaped suture ligation(weaving the thread up and down in a loop - shaped pattern, leaving a space of 2 cm between each loop) with a straight needle and prolene 2 - 0. After skin incision, we proceeded the dissection toward the central and inferior side of the mass obliquely while we avoided breaking large vascular sinuses. We resected the tumor in a wedged - shape. Subcutaneous tissue was sutured layer by layer and skin was closed by vertical mattress and interrupted suture. The loop - shaped ligation of the base was removed and compressive dressing was done with gauzes and elastic bandages. Results: Postoperative complications such as infection, hemorrhage, hematoma, and dehiscense did not occur. Perioperatively the patient was sufficiently transfused with five units of blood and two units of fresh frozen plasma. During the subsequent 1 year follow - up, the functional and cosmetic result was excellent. Conclusion: A continuous loop - shaped suture ligation procedure along the base of the giant NF effectively reduced the amount of hemorrhage during the operation, made dissection and ligation of vessels easily and quickly, and shorten the operating time and postoperative recovery time.