• Title/Summary/Keyword: Liner change

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A STUDY ON THE ADHESION OF A SOFT LINER CONTAINING 4-META TO THE BASE METAL ALLOY AND ITS VISCOELASTIC PROPERTY

  • Park Hyun-Joo;Kim Chang-Whe;Kim Yung-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.6
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    • pp.732-746
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    • 2003
  • Statement of problem. Soft lining materials, also referred to as tissue conditioning materials, tissue heating materials, relining materials, soft liners or tissue conditioners, were first introduced to dentistry by a plastic manufacturer in 1959. Since the introduction of the materials to the dental field, their material properties have been continually improved through the effort of many researchers. Soft lining materials have become widely accepted, particularly by prosthodontists, because of their numerous clinical advantages and ease of manipulation. Unfortunately, few reports have been issued upon the topic of increasing the bond strength between the base metal alloy used in cast denture bases and PMMA soft liner modified with 4-META, nor upon the pattern of debonding and material change in wet environment like a intra oral situation. Purpose. The purposes of this study were comparing the bond strength between base metal alloy used for the cast denture bases and PMMA soft liner modified with 4-META, and describing the pattern of debonding and material property change in wet environment like the intraoral situation. Material and Methods. This study consisted of four experiments: 1. The in vitro measurement of shear bond strength of the adhesive soft liner. 2. The in vitro measurement of shear bond strength of the adhesive soft liner after 2 weeks of aging. 3. A comparison of debonding patterns. 4. An evaluation the Relation time of modified soft liner. The soft liner used in this study was commercially available as Coe-soft (GC America.IL.,USA), which is provided in forms of powder and liquid. This is a PMMA soft liner commonly used in dental clinics. The metal primer used in this study was 4-META containing primer packed in Meta fast denture base resin (Sun Medical Co., Osaka, Japan). The specimens were formed in a single lap joint desist which is useful for evaluating the apparent shear bond strength of adhesively bonded metal plate by tensile loading. Using the $20{\times}20mm$ transparent grid, percent area of adhesive soft liner remaining on the shear area was calculated to classify the debonding patterns. To evaluate the change of the initial flow of the modified adhesive soft liner, the gelation time was measured with an oscillating rheometer (Haake RS150W/ TC50, Haake Co., Germany). It was a stress control and parallel plate type with the diameter of 35mm. Conclusion. Within the conditions and limitations of this study, the following conclusions were drawn as follows. 1. There was significant increase of bond strength in the 5% 4-META, 10% 4-META containing groups and in the primer coated groups versus the control group(P<0.05). 2. After 2 weeks of aging, no significant increase in bond strength was found except for the group containing 10% 4-META (P<0.05). 3. The gelation times of the modified soft liner were 9.3 minutes for the 5% 4-META containing liner and 11.5 minutes for the 10% 4-META liner. 4. The debonding patterns of the 4-META containing group after 2 weeks of aging were similar to those of immediaely after preparation, but the debonding pattern of the primer group showed more adhesive failure after 2 weeks of aging.

A Numerical Simulation of Regenerative Cooling Heat Transfer for the Rocket Engine (로켓엔진의 재생 냉각 열전달 해석)

  • 전종국;박승오
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.05a
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    • pp.127-130
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    • 2003
  • This paper presents the numerical thermal analysis for regeneratively cooled rocket thrust chambers. An integrated numerical model incorporates computational fluid dynamics for the hot-gas thermal environment, and thermal analysis for the liner and coolant channels. The flow and temperature fields in rocket thrust chambers is assumed to be axisymmetric steady state which is presumed to the combustion liner. The heat flux computed from nozzle flow is used to predict the temperature distribution of the combustion liner. As a result, we present the wall temperature of combustion liner and the temperature change of coolant.

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Responses to 1-MCP during Storage of Kimchi Cabbage Ryouckgwang Cultivar (배추 력광 품종의 저장 중 1-MCP에 대한 반응)

  • Hong, Sae Jin;Kim, Byung-Sup;Kim, Byeong-Sam;Eum, Hyang Lan
    • Journal of Bio-Environment Control
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    • v.27 no.2
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    • pp.125-131
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    • 2018
  • The effect of 1-methylcyclopropene (1-MCP) in the storability of kimchi cabbage at cold storage condition was investigated. Kimchi cabbage (Brassica campestris L. cv Ryouckgwang) was divided four groups, forced air cooling (FAC), FAC + 0.03 mm linear low density polyethylene liner (Liner), $FAC+2{\mu}L{\cdot}L^{-1}$ 1-MCP (1-MCP), and FAC + 1-MCP + Liner. After each treatment kimchi cabbage was stored at $2^{\circ}C$, 95% RH. Quality parameters were weight loss, soluble solids content (SSC), firmness, and color ($CIE\;L^*$, $a^*$, $b^*$, chroma, hue angle). Weight loss during storage was showed significant difference by Liner treatment. In particular FAC + 1-MCP + Liner treatment showed 12.5% reduction after 6 weeks of storage period and minimized the weight loss rate compared to other treatments. SSC of kimchi cabbage was $2.5^{\circ}Brix$ at harvest and FAC + 1-MCP + Liner treatment maintained the SSC until 3 weeks, while in other treatments gradually were increased. The firmness of kimchi cabbage was 24.0 N immediately after harvest and the firmness at harvest time tended to be maintained at 22.6 N after 6 weeks of storage in FAC + 1-MCP + Liner treatment. During the storage period, the color change of the kimchi cabbage leaf can be confirmed by $CIE\;a^*$ and hue angle value. 1-MCP treatment alone did not affect the color change, however 1-MCP + Liner treatment was able to maintain the chromaticity at harvest time while minimizing the change of $CIE\;a^*$ and hue angle. These results suggest that 1-MCP treatment is not effective for the storage of kimchi cabbage but can be maintained for up to 6 weeks when treated with Liner.

Two-dimensional Thermal Analysis for Carbonacious Thermal Liner of Rocket Nozzle with Ablation and In-depth Pyrolysis (삭마 및 내부 열분해를 고려한 로켓노즐 탄소계 내열재의 2차원 열해석)

  • 황기영;강윤구
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.2
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    • pp.37-47
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    • 1999
  • This paper describes the thermal analysis which can calculate the ablation depth and temperature distribution of the rocket nozzle liner allowing geometry change caused by the ablation of nozzle liner. In this analysis, Zvyagin's model is used for surface ablation and Yaroslavtseva's model for in-depth pyrolysis. A deforming finite-element grid is used to account for external-boundary movement due to the erosion of thermal liner. The accuracy of the present numerical method is evaluated with a rocket nozzle liner and the numerical solutions are favorably agreed with experimental data. The temporal variations of temperature and ablation depth at the thermal liner of another rocket nozzle are numerically simulated and the results are discussed. Special emphasis is given to the effects of kinetic constants for carbon-carbon and carbon-phenolic composites on the ablation depth of thermal liner.

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A study on behavior characteristics of liner plate with depth (토피고 변화에 따른 Liner Plate 거동특성에 관한 연구)

  • Jeong, Ji-Su;Ji, Young-Hwan;Cho, Hyun;Hur, In-Young;Lee, Seung-Ho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.2
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    • pp.131-139
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    • 2012
  • In this study, the numerical analysis has been conducted in order to check behavior characteristics of liner plate made of corrugated steel from urban small sized tunnel excavation. The analysis was conducted with five kinds of conditions like 5 m, 10 m, 15 m, 20 m and 25 m to examine the behavior characteristics of liner plate according to the depth of cover. Analysis results showed that the maximum axial stress and the maximum displacement occurs in the lower end of the member, and the maximum shear stress occurs in the upper part of the member. Also, change of displacement, stress shearing stress of liner plate based on various depth of cover are existed, but the difference is slight, and by increasing depth of cover, structural stability is gradually ensured.

THE RHEOLOGY OF THE SOFT LINER WITH 4-META

  • Park, Hyun-Joo;Kim, Chang-Whe
    • The Journal of Korean Academy of Prosthodontics
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    • v.40 no.3
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    • pp.269-274
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    • 2002
  • statement of problem The viscoelastic property is the most important and peculiar characteristics of soft liners. But the authorized standard is not certainly established than other dental materials. purpose of study This study is aimed to compare the initial flow of gelation of the modified soft liner with 4-META with that of PMMA soft liners using dynamic method and evaluate the clinical acceptance of the trial materials. materials and method This study consists of 3 groups with the given % of 4-META powder in the Coe soft liquid; 0%, 5%, 10% Each group was tested for 10 times to record the change of G′values during 3 hours. the gelation time was recorded by the oscillating rheometer with parallel plate with 1 rad/sec. results As the results of this study, the gelation time of modified soft liner was elongated by 5 to 6 minutes. conclusion The mean gelation time of modified soft liner could be within the range of clinically acceptable.

A Study on Improvement of Adhesion HTPB Propellant/Liner/Insulation (HTPB계 추진제/라이너/내열재의 접착력 향상에 관한 연구)

  • Park, Sungjun;Song, Jongkwon;Park, Euiyong;Rho, Taeho;Choi, Sunghan
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.4
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    • pp.92-97
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    • 2019
  • A study was conducted to improve the adhesion of propellant, liner,and insulation. Insulation was shown to be more advantageous in improving the adhesion when a barrier coat was applied compared to a bare insulation layer. It was confirmed that the adhesion strength between the insulation and the propellant improves as the thickness of the liner coating increases. The liner was cured for 24 h. If the liner is cured for a long time, it will adversely affect adhesion. Adhesion is also improved when a bonding agent is applied. As the bonding agent content increases, the adhesion improves. There is a change in the adhesive strength depending on the type of bonding agent used. HX-868 shows slightly more improved adhesion than HX-752.

A Study on the International Competitiveness of the Korea Liner Shipping Commany (우리나라 정기선사의 국제경쟁력에 관한 연구)

  • Lee, Jae-Kyu
    • Korean Business Review
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    • v.11
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    • pp.365-384
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    • 1998
  • Under the rapid change of the world shipping industry, the liner shipping company in Korea should initiate the adaptation power, counterplot for survival, and continuous development. The world shipping industry is in the middle of the wave for the liberalization and openness of it. According to this change in world shipping industry, it is the fact that government policy for shipping industry should start turning its direction from the protectionism to the liberalism. Under this kinds of situations, this study firstly treated the liner shipping company and its governmental policy of Korea and Japan. Based on those studies, analysis of the liner shipping company operation and management reality was executed. Through the execution of studies, the problems which should be solved for development occurred. Furthermore, this thesis takes two way of researches of literature and actual proof for reinforcement plan of international competitiveness. This standard time period of study is set in 1993 except the irregular liner shipping company.

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A study on the effects and repeal of the block exemption for liner conferences (EU의 정기선 해운동맹 포괄면제 폐지와 그 영향에 관한 연구)

  • Choi, Byoung-Kwon;Shin, Gun-Hoon;Lee, Byung-Mun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.45
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    • pp.165-188
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    • 2010
  • The repeal of the block exemption for liner conferences and the abolition of any "special EC antitrust regime" for the shipping industry marks an important step in European maritime competition policy. This article examines the origins and the rationale of the EC antitrust immunity granted so far to the shipping industry and explains the causes of this historical change. Moreover, based on the precedents which have appeared so far, a general assessment is offered under this new EC regime on agreements restricting competition in the liner shipping industry, in particular horizontal ones: conference and tariff/freight arrangements will be doomed, whereas the legitimacy of consortia agreements should not be cast in doubt; a case-by-case analysis will be the approach as regards exchange or dissemination of information by shipowners in the market, and the relevant case law which emerges on these matters in other industries will be the criterion for their evaluation. Finally, a few remarks are made in respect of the international dimension of the decision to outlaw liner conferences and hence carve out EU Member States from the UN Code of Conduct regime.

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On the Construction of Cotton Tyeollik in Middle of Chosun Period - Through the Process of Reconstructing Tyeollik Excavated from Lady Kim's Tomb- (조선중기 솜텰릭(첩리) 구성에 대하여 - 순천 김씨묘 갈색명주솜누비털릭 중심으로 -)

  • 장인우
    • Journal of the Korean Society of Costume
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    • v.52 no.8
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    • pp.109-122
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    • 2002
  • This study is to understand cotton Tyeollik construction of the middle Chosun Period through the reconstruction of tyeoilik which was excavated from lady kim's tomb (from sooncheon). The form of excavated Tyeollik classified into two types by the location of waistline. The structure of excavated tyeollik classified into three types by the construction(one-layer, two-layer, cotton/quilt) The form type change according to the period. The change of the form type has the close relation structure type in the tyeollik. Cotton-tyeollik belongs to the form of the front time. The construction of cotton tyeollik is similar with the one-layer Tyeollik Exception the construction of git(collar) and the size and direction of the fold. The surface pattern is composed of two-pieces but the liner is one-piece in the Git(collar). and In The size of fold surface is o.2-o.3cm, and liner is 0.5-0.8cm. The direction of fold in the liner is the contrast with the surface.