• 한국기계가공학회지
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• 제19권8호
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• pp.104-109
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• 2020

Recently, vibration and noise have become an important issue in the auto industry. Asphalt vibration damping pads are used to reduce the noise and vibration of automobile bodies, and asphalt is used for many mass-produced parts due to its simple attachment process and low processing costs. In this study, the self-adhesion of asphalt pads using Joule heating was evaluated. To create the asphalt pad for the experiment, the asphalt pad was molded into a specific thickness by using SGACC material and rubber used in the vehicle body as a main component and a modified resin and filler. The SGACC material was 200 mm in length, 200 mm in width, and 0.7 mm in thickness. The asphalt pad was 200 mm in length, 100 mm in width, and 3 mm in thickness. The equipment was composed of a TR (Transformer) DC254kVA and a TC (Time controller) for a current of up to 20,000 A. The current for the Joule heating was set to 7.0 kA and a 3/1 cycle, for which the adhesion of the asphalt pad over the current flow time was evaluated.

• The Korean Journal of Pain
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• 제10권2호
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• pp.214-219
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• 1997

Background: Epidural neural blockade with local anesthetics combined with steroids has been in clinical trials for patients with low back pain. But pain treatment of low back pain remains somewhat problematic. Many patients with low back pain have epidural fibrosis and adhesions proved with magnetic resonance imaging(MRI) examination. These findings might play an important role in the origin of back pain. Present study was aims to investigate the effect of epidural adhesiolysis in patients with low back pain. Methods: We investigated 76 patients suspected with epidural fibrosis and adhesion was suspected. Nerve pathology was demonstrated and epidural fibrosis suspected or proved with MRI examination. 17G needle specially designed by Racz was inserted at sacral hiatus and catheter was inserted untill its tip was located at lesion site under fluoroscopic guidance. Injection of contrast dye was achieved and prospected spread of agents. Injection of 0.25% bupivacaine, triamcinolone, and 10% hypertonic saline via catheter were carried out daily for 3 days. Evaluation included assessment of pain relief (Numerical Rating Scale; NRS) post-epidural adhesiolysis 3 days, 1 week, and 3 months. We also looked for complication of epidural adhesiolysis. Results: Statistical analysis(Friedman nonparametric repeated measures test and Dune's multiple comparison test) demonstrated NRS was significantly less during 3 months after epidural adhesiolysis(P<0.05). Especially, there is a extremely significance in post-epidural adhesiolysis 3 days (P<0.001). Only four patients reported any complications the most common symptom among three persistent headache but disappeared after a few months without residual sequelae. Conclusion: We conclude epidural adhesiolysis is a safe and effective method of pain therapy for low back pain with proven lumbo-sacral fibrosis and adhesion. A direct visualization by epiduroscopy may be more useful to the resulting functional changes after epidural adhesiolysis.

• 대한수의학회지
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• 제39권6호
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• pp.1210-1217
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• 1999

This study was carried out to develop a newly designed ovum pick-up(OPU) instrument for ultrasound-guided transvaginal follicular aspiration in cows. This new instrument consists of out- & inner-layer stainless pipes and a grip with a trigger(hand) switch. Some gauge types of disposable needles and tubes can be attached to this inner pipe. With this instrument, while grasping an ovary with one hand, the other hand can handle in apiration and vacuum on/off with the least assitant's help. With this instrument the mean recovery rate of bovine follicular oocytes was 45.2%. In recovered oocytes, usable oocytes(Grade I & II) were 30.4% and this rate meant 1.4 oocytes per ovary. For 30 days after initial aspiration with this instrument, some adverse effects such as adhesion, hemorrhage, hematoma and other mass formation in/with ovaries were also examined by rectal examination, ultrasonographic and endoscopic images. Adhesion was found in one ovary 1 week after aspiration, and hemorrhagic lesion was found 1-2 days and petechia were found 3-5 days after aspiration and there was no remarkable adverse effects. It was found that this instrument could be applicable and safe for ovum pick-up in cows.

• 접착 및 계면
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• 제5권2호
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• pp.14-26
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• 2004

For reliable determination of mechanical characteristics of adhesively bonded joints used e.g. as input data for computer-aided design of complex components, the thick-adherend tensile-shear test according to ISO 11003-2 is the most important material testing method. Although the total displacement of the joint is measured across the polymer layer directly in the overlap zone in order to minimize the influence of the stepped adherends, the substrate deformation must be taken into account within the framework of the evaluation of the shear modulus and the maximum shear strain, at least when high-strength adhesives are applied. In the standard ISO 11003-2 version of 1993, it was prescribed to perform the substrate deformation correction by means of testing a one-piece reference specimen. The authors, however, pointed to the excessive demands on the measuring accuracy of the extensometers connected with this technique in industrial practice and alternatively proposed a numerical deformation analysis of a dummy specimen. This idea of a mathematical correction was included in the revised ISO 11003-2 version of 2001 but in the simplified form of an analytical method based on Hooke's law of elasticity for small strains. In the present work, it is shown that both calculation techniques yield considerably discordant results. As experimental assessment would require high-precision distance determination (e.g. laser extensometer), finite element analyses of the deformation behavior of the bonded joint are performed in order to estimate the accuracy of the obtained substrate deformation corrections. These simulations reveal that the numerical correction technique based on the finite element deformation modeling of the reference specimen leads to considerably more realistic results.

• Composites Research
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• 제25권3호
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• pp.76-81
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• 2012

대기압 플라즈마 처리를 통해 탄소나노튜브(CNT) 표면은 개질 되며 개질된 입자의 표면과 탄소섬유 강화 CNT 페놀 복합재료간에 계면접착력에 변화를 확인하였다. CNT 표면에 플라즈마 처리에 따라 표면 변화가 발생되고 표면 개질의 결과를 확인하기 위해 FT-IR을 사용하였다. 또한, 정적 접촉각 실험법을 통해 플라즈마 처리에 따른 CNT의 젖음성을 비교 평가하였다. 순수 CNT 입자의 접촉각은 $118^{\circ}$ 였으나, 플라즈마 처리를 할 경우 $60^{\circ}$도로 표면 개질을 통해 젖음성이 향상됨을 확인하였다. 탄소섬유와 CNT-페놀복합재료 간 계면접착력은 플라즈마 처리에 따라 겉보기 강성도가 증가되는 결과를 확인하였으며, 음향방출 실험법과 전기저항 측정법을 병행한 이중기지평가법을 통해 계면전단강도 (IFSS)를 계산하여 계면접착력 향상을 확인하였다.

• 한국건축시공학회지
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• 제20권1호
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• pp.35-41
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• 2020

외단열 마감 공법에서 사용되는 얇은 바름재는 아크릴 에멀젼을 주 소재로 한 마감재이다. 본 연구에서는 실란 개질 아크릴 에멀젼과 실리카 분산아크릴 에멀젼을 치환하였을때 특성을 평가하였다. 실험결과, 실란 개질 아크릴 에멀젼은 인장강도 개선에는 큰 효과는 없었으나 부착강도, 물흡수계수, 온냉반복저항성의 성능 개선에 효과적인 것으로 나타났다. 실리카 분산 아크릴 에멀젼은 인장강도 개선에 효과적이며, 10%의 치환율에서는 부착강도, 물흡수계수, 온냉반복저항성의 성능 개선에 효과적인 것으로 나타났다. 이를 통해 아크릴 에멀젼의 성능을 향상할 수 있는 복합 에멀젼을 제조할 수 있는 것으로 판단되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.78-80
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• 2014

Silicone structural glazing (SSG) is a method utilizing a silicone adhesive to attach glass, metal, or other panel material to the structure of a building. Windload and other impact loads on the facade are transferred from the glass or panel through the silicone structural sealant to the systems' framework. Silicone structural glazing systems are currently a very common method of glazing throughout the world. Locally, structural silicone glazing has become very common to achieve aesthetically pleasing and high utilization of small land for both residential and commercial building. Although structural silicone glazing has been utilized for approximately thirty years in Korea, the understanding of its technology was low and limited. Consequently, Korean projects experienced many quality issues during assembly and construction, even in very recently finished buildings. Adhesion loss and water infiltration occurred on more than one project, and the time and cost to repair these issues were substantial. In general, there are two kinds of structural silicones depending on fabrication methods. 1part structural silicone is for site glazing system and 2part structural silicone is for unitized factory glazing system. In this paper, 2part structural silicone which is very common for factory fabricating curtainwall systems was evaluated with regards to various mixing ratio. Since the structural performance of 2part sealant can be affected by mixing ratios, some extra ranges of recommended mixing ratio were evaluated to see any performance differences. Besides on cure profile, comparative evaluations for mechanical properties and adhesion develop on common building substrates were conducted.

• 접착 및 계면
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• 제13권1호
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• pp.9-16
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• 2012

접착용 테이프 박리거동에 미치는 외부효과를 알아보고, 이를 설명하는 준강체 실린더 체인(semi-rigid body cylinder chain) 모델을 제안하였다. 먼저 평면으로부터 테이프를 떼어낼 때, 테이프의 거동을 정성적으로 파악하고, 이를 토대로 준강체 실린더 체인 모형을 도식화하였다. 그 다음 테이프를 떼어내는 힘에 미치는 여러 요소들(온도, 표면거칠기, 떼어내는 속도, 각도 의존성, 테이프 폭 등)의 효과와 이들의 민감도를 분석하여 동일한 실험 기준조건을 설정하고, 이 조건에서 평면으로부터 테이프를 떼어내는 힘(벡터)의 각도 의존성을 $10^{\circ}$ 간격으로 측정하였다. 실험결과는 본 연구에서 확립한 모형이론과 실험오차범위 내에서 잘 일치하였고, 다른 요소들의 효과는 현상론적 입장에서 정성적으로 잘 설명되었다. 이러한 이유로, 본 결과는 PSA 테이프의 접착력을 시험 평가하는 모델로 활용될 수 있을 것으로 기대된다.

• Korean Journal of Acupuncture
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• 제24권3호
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• pp.117-137
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• 2007

Objectives & Methods : The purpose of this study is to observe the effects of Gentianae macrophyllase Radix herbal-acupuncture solution(GR-HAS) at Joksamni(ST36) on Collagen-induced arthritis(CIA) in DBA/1J mice. The author performed several experimental items to analyze arthritis evaluation, change of weight, spleen size and adhesion rate, change of cytokine level, IgG, IgM and anti-collagen II , change of immunocyte count, histological change of CIA mouse joint related with RA. Results : 1. In the GR-HA group, the arthritis index, the incidence of arthritis and joint edema were significantly decreased. 2. In GR-HA group, there were no weight loss and similarly maintained as normal group. Spleen size, adhesion rate and the edema and transformation of knee joint were low and similarly maintained as normal group. 3. In the GR-HA, cytokine level, IgG, IgM and anti-collagen II were significantly decreased. 4. In the GR-HA, the change of immunocyte count were similarly maintained as normal group. 5. In the histological changes of the CIA mouse joint, the cartilage destruction and synovial cell proliferation were decreased in the GR-HA(Hematoxylin and eosin stain). The collagen fiber expressions in the GR-HA were similar with that of the normal group(Masson's Trichrome stain) Conclusions : These results suggest that GR-HA at ST36 has an effect to control immune reaction and suppress inflammation, synovial cell proliferation and cartilage destruction in rheumatoid arthritis.

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.51-62
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• 2022

Lactobacillus rhamnosus SKG34 (LrSKG34), a potential probiotic strain, was successfully isolated from Sumbawa Mare's milk. Our previous studies showed that the strain is resistant to gastrointestinal conditions, possesses antioxidant activity, and lowers blood cholesterol levels. Further clarification of the potential probiotic characteristics and safety assessment are necessary. This study aimed to evaluate the adhesion of LrSKG34 to Caco-2 cell monolayers and its effect on mucosal integrity in vitro. We also examined the LrSKG34 safety profile based on antimicrobial susceptibility testing, haemolytic activity determination, Caco-2 cell monolayer translocation evaluation, and in vivo investigation of the effect of LrSKG34 on the physiology, biochemical markers, and histopathological appearance of major organs in an animal model. LrSKG34 attached to Caco-2 cell monolayers and maintained mucosal integrity in vitro. The typical resistance of lactobacilli to ciprofloxacin, gentamicin, vancomycin, trimethoprim-sulfamethoxazole, and metronidazole was confirmed for LrSKG34. No haemolytic activity was observed on blood agar plates, and no LrSKG34 translocation was observed in Caco-2 cell monolayers. Administration of LrSKG34 to Sprague-Dawley rats did not adversely affect body weight. No abnormalities in hematological parameters, serum biochemistry levels, or histopathological structures of major organs were observed in LrSKG34-treated rats. Collectively, the results implicate LrSKG34 as a promising and potentially safe probiotic candidate for further development.