• Title/Summary/Keyword: reinforcement methods

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Literatual Study on Etiological Analysis, Pathogenesis and Acupuncture Treatment of Edema (수종(水腫)의 병인병기(病因病機) 및 침구치료(鍼灸治療)에 대한 문헌적(文獻的) 고찰(考察))

  • Oh, Chang-rok;Na, Gun-ho;Choi, Bong-gyun;Yoon, Jung-sun;Lyu, Chung-yeol;Cho, Myung-rae
    • Journal of Acupuncture Research
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    • v.22 no.3
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    • pp.253-270
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    • 2005
  • Objective : The purpose of this study is to establish a category for acupuncture therapy by appropriate etiological analysis and differenciation of edema. Methods : We arrange Huang Di Nei Jing and thirty four kinds of literature about edema. Results : 1. The cause of Edema is functional disorder of lung, spleen, kidney, bladder and tri-energizer by six kinds of natural factors, internal injury and loss of nutritions. 2. Edema compartmentalize into the water of five zang organs, several kinds of edema(e,g. 5, 10, 12, 24) and yang & yin edema. 3. An ultimate cause of edema pathogenesis is the disturbance of Qi function in kidney. 4. In view of the results so far achived,'GV26(水淸)' is a vitally important acupoint in acupuncture treatment of edema.'GV26(水淸)' and 'CV9(水分)' are very useful acupoints in moxibustion. 5. In the acupuncture and moxibustion treatment of yang edema, we can use acupoints as like 'GV26(水溝)', 'S36(足三里)', 'B20(脾兪)' and 'SP9(陰陵泉)' by purgation and reduction for expelling wind, reducing fever and eliminating dampness. In an instance of yin edema, we can use acupoints as like 'CV9(水分)' 'S36(足三里)', 'CV6(氣海)', 'B20(脾兪)', 'B23(腎兪)' and 'K3(太谿)' by reinforcement for tonifying spleen yang-middle energizer-, qi-transmission and water promoting.

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MICROLEAKAGE AND WATER STABILITY OF RESIN CEMENTS

  • Choi Sun-Young;Lee Sun-Hyung;Yang Jae-Ho;Han Jung-Suk
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.3
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    • pp.369-378
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    • 2003
  • Statement of Problem: Recently, resin cements have become more widely used and have been accepted as prominent luting cements. Current resin cements exhibit less microleakage than conventional luting cements. However, the constant contact with water and exposure to occlusal forces increase microleakage even in resin cements inevitably. Most bonding resins have been modified to contain a hydrophilic resin such as 2-hydroxyethylmethacrylate (HEMA) to overcome some of the problems associated with the hydrophobic nature of bonding resins. By virtue of these modifications, bonding resins absorb a significant amount of water, and there may also be significant stresses at bonding interfaces, which may adversely affect the longevity of restorations. Therefore the reinforcement of water stability of resin cement is indispensable in future study. Purpose: This study was conducted to examine the influence of water retention on microleakage of two resin cements over the period of 6 months. Materials and Methods: 32 extracted human teeth were used to test the microleakage of a single full veneer crown. Two resin cements with different components and adhesive properties - Panavia F (Kuraray Co., Osaka, Japan) and Super-Bond C&B (Sun Medical Co., Kyoto, Japan)- were investigated. The storage medium was the physiological saline solution changed every week for 1 month, 3 months, and 6 months. One group was tested after storage for 1 day. At the end of the each storage period, all specimens were exposed to thermocycling from $5^{\circ}C$ to $55^{\circ}C$ of 500 cycles and chewing simulation of 50,000 cycles, and then stained with 50% silver nitrate solution. The linear penetration of microleakage was measured using a stereoscopic microscope at ${\times}40$ magnification and a digital traveling micrometer with an accuracy of ${\pm}3{\mu}m$. Values were analyzed using two-way ANOVA test, Duncan's multiple range tests (DMRT). Results : Statistically significant difference of microleakage was shown in the 3-month group compared with the1-day or 1-month group in both systems (p<0.05) and there were statistically significant differences in microleakage between the 3-month group and the 6-month group in both systems (p<0.05). The two systems showed different tendency in the course of increased microleakage during 3 months. In Panavia F, microleakage increased slowly throughout the periods. In Super-Bond C&B, there was no significant increase of microleakage for 1 month, but there was statistically significant increase of microleakage for the next 2 months. For the mean microleakage for each period, in the 3-month group, microleakage of Super-Bond C&B was significantly greater than that of Panavia F. On the other hand, in the 6-month group, microleakage of Panavia F was significantly greater than that of Super-Bond C&B (p<0.05). Conclusion: Within the limitation of this study, water retention of two different bonding systems influence microleakage of resin cements. Further studies with the longer observation periods in viro are required in order to investigate water stability and the bonding durability of the resin cement. CLINICAL IMPLICATIONS Microleakage at the Cement-tooth interfaces did not necessarily result in the failure of the crowns. But it is considered to be a major factor influening the longerity of restorations. Further clinical approaches for decreasing the amount of microleakage are required.

The fracture resistance of heat pressed ceramics with wire reinforcement (금속선 강화에 따른 열 가압 도재의 파절저항)

  • Jo, Deuk-Won;Dong, Jin-Keun;Oh, Sang-Chun;Kim, Yu-Lee
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.2
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    • pp.191-198
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    • 2009
  • Statement of problem: Ceramics have been important materials for the restoration of teeth. The demands of patients for tooth-colored restorations and the availability of various dental ceramics has driven the increased use of new types of dental ceramic materials. Improved physical properties of theses materials have expanded its use even in posterior crowns and fixed partial dentures. However, ceramic still has limitation such as low loading capability. This is critical for long-span bridge, because bridge is more subject to tensile force. Purpose: The wire reinforced ceramic was designed to increase the fracture resistance of ceramic restoration. The purpose of this study was to evaluate the fracture resistance of wire reinforced ceramic. Material and methods: Heat pressed ceramic(ingot No.200 : IPS Empress 2, Ivoclar Vivadent, Liechtenstein) and Ni-Cr wire(Alfa Aesar, Johnson Matthey Company, USA) of 0.41 mm diameter were used in this study. Five groups of twelve uniform sized ceramic specimens(width 4 mm, thickness 2 mm, length 15 mm) were fabricated. Each group had different wire arrangement. Wireless ceramic was used as control group. The experimental groups were divided according to wire number and position. One, two and three strands of wires were positioned on the longitudinal axis of specimen. In another experimental group, three strands of wires positioned on the longitudinal axis and five strands of wires positioned on the transverse axis. Three-point bending test was done with universal testing machine(Z020, Zwick, Germany) to compare the flexural modulus, flexural strength, strain at fracture and fracture toughness of each group. Fractured ceramic specimens were cross-sectioned with caborundum disc and grinded with sandpaper to observe interface between ceramic and Ni-Cr wire. The interface between ceramic and Ni-Cr wire was analyzed with scanning electron microscope(JSM-6360, JEOL, Japan) under platinum coating. Results: The results obtained were as follows: 1. The average and standard deviation in flexural modulus, flexural strength and fracture toughness showed no statistical differences between control and experimental groups. However, strain was significantly increased in wire inserted ceramics(P<.001). 2. Control group showed wedge fracture aspects across specimen, while experimental groups showed cracks across specimen. 3. Scanning electron microscopic image of cross-sectioned and longitudinally-sectioned specimens showed no gap at the interface between ceramic and Ni-Cr wire. Conclusion: The results of this study showed that wire inserted ceramics have a high strain characteristic. However, wire inserted ceramics was not enough to use at posterior area of mouth in relation to flexural modulus and flexural strength. Therefore, we need further studies.

A Case study and Analysis on the Up-Lift Pressure Treatment Evaluation of Underground Installations for their Efficient Adoption (사례분석을 통한 효율적 상향수압(Up-Lift Pressure) 처리공법 적용방안에 관한연구 - ◯◯ 상업지역 현장사례 중심으로 -)

  • Ko, Ok-Yeol;Kwon, Oh-Chul;Shim, Jae-Kwang;Park, Tae-Eun
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.119-129
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    • 2009
  • Building construction trends have been changed dramatically in terms of size and mass. With the need to maximize land usage, there has been an increase in the construction of high-rise buildings. This affects not only the entire construction duration and cost, but also subsequent construction activities, such as work to increase underground facilities and in reclamation land area construction. These types of site conditions require soft ground reinforcement and the proper uplift water pressure treatment. In general, two kinds of methods have been used for uplift water pressure treatment systems. However, there have been some problems arising as the result of a lack of research and analysis on underground construction techniques, and a reliance on experiments over actual survey and analysis of site conditions. This paper focused on the problems of conventional selection procedure, by analyzing drawings and proposing a kind of modeling for a reasonable procedure. The results were applied to OO project as a sample construction case to be verified in this research. The initial plan in the case project was the Rock Anchor System. However, as there were terrible miscalculations of basic site conditions that had an extraordinary influence on the underground water level, such as the site's proximity to the Han-river, it was necessary to change the plan to include apermanent drainage system. This achieved a direct construction cost reduction \ 406,702,000 and a maximum sayings of 4% of operational cost, based on the 50-year building Life Cycle Cost.

Pledget as a Useful Substitute for a Knot in Intracorporeal Continuous Gastrointestinal Suturing (복강 내 위장관 연속 손바느질에서 매듭 대용으로서의 Pledget의 유용성)

  • Kim, Jin-Jo;Song, Kyo-Young;Kim, Sung-Keun;Jun, Kyong-Hwa;Chin, Hyung-Min;Kim, Wook;Jeon, Hae-Myung;Park, Cho-Hyun;Park, Seung-Man;Lim, Keun-Woo;Park, Woo-Bae;Kim, Seung-Nam
    • Journal of Gastric Cancer
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    • v.7 no.3
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    • pp.146-151
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    • 2007
  • Purpose: Pledget is a PTFE felt that is usually used for suture reinforcement in cardiovascular surgery. In order to minimize the difficulty in intracorporeal continuous gastrointestinal suturing by reducing the number of tied knots, we have used pledget as substitute for a knot (pledget suturing). Materials and Methods: Thirty-two consecutive patients who underwent totally laparoscopic uncut Roux-en-Y gastrojejunostomy after distal gastrectomy in our institution were enrolled in this study, and the patients were divided into three groups according to the method of intracorporeal anastomosis. Basically, intracorporeal anastomosis was performed by several firings of linear staplers; however, the entry holes for the stapler at the jejunojejunostomy and the gastrojejunostomy were closed by pledget suturing in group A (8 patients), the entry hole for the stapler at jejunojejunostomy was closed by conventional suturing in group B (8 patients), and all of the entry holes for the stapler were closed by stapling in group C (16 patients). The surgical outcomes of each group were compared to each other. Results: The anastomotic time in group A was not longer than in group B, although there were more sutures used in group A, but it was longer than in group C. The number of stapler cartridges used in group A was the smallest among the three groups. In group B, there were two cases of a break of suture material during anastomosis, there were no such cases in group A. There was no complication related to anastomosis in all of the groups. Conclusion: Pledget was found to be useful for minimizing the difficulty in intracoproreal continuous gastrointestinal suturing and reducing the number of stapler cartilages used in intracorporeal anastomosis.

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Estimation of Allowable Bearing Capacity and Settlement of Deep Cement Mixing Method for Reinforcing the Greenhouse Foundation on Reclaimed Land (간척지 온실기초 보강을 위한 심층혼합처리공법의 허용지내력 및 침하량 산정)

  • Lee, Haksung;Kang, Bang Hun;Lee, Kwang-seung;Lee, Su Hwan
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.287-294
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    • 2021
  • In order to expand facility agriculture and reduce greenhouse construction costs in reclaimed land, a greenhouse foundation method that satisfies economic feasibility and structural safety at the same time is required. As an alternative, the allowable bearing capacity and settlement were reviewed when the DCM(Deep cement mixing) method was applied among the soft ground reinforcement methods. To examine the applicability of the greenhouse foundation, the allowable bearing capacity and settlement were calculated by applying the theory of Terzaghi, Meyerhof, Hansen, and Schmertmann. In case of the diameter of 800mm and the width and length of the foundation of 4m, the allowable bearing capacity was 179kN/m2 and the settlement was 7.25mm, which satisfies the required bearing capacity and settlement standards. The calculation results were verified through FEM(Finite element method) analysis using the Mohr-Coulomb material model. The allowable bearing capacity was 169kN/m2 and the settlement was 2.52mm. The bearing capacity showed an error of 5.6% compared to calculated value, and the settlement showed and error of 65.4%. Through theoretical calculations and FEM analysis, it was confirmed that the allowable bearing capacity and settlement satisfies the design criteria as a greenhouse foundation when the width and length of the foundation were 4m. Based on the verified design values, it is expected to be able to present the foundation design criteria for greenhouses through empirical tests such as bearing capacity tests and long-term settlement monitoring.

The structural analysis and design methods considering joint bursting in the segment lining (조인트 버스팅을 고려한 세그먼트 라이닝 구조해석 및 설계방법)

  • Kim, Hong-Moon;Kim, Hyun-Su;Jung, Hyuk-Il
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.6
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    • pp.1125-1146
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    • 2018
  • Segment lining applied to the TBM tunnel is mainly made of concrete, and it requires sufficient structural capacity to resist loads received during the construction and also after the completion. When segment lining is design to the Limit State Design, both Ultimate Limit State (ULS) and Service Limit State (SLS) should be met for the possible load cases that covers both permanent and temporary load cases - such as load applied by TBM. When design segment lining, it is important to check structural capacity at the joints as both temporary and permanent loads are always transferred through the segment joints, and sometimes the load applied to the joint is high enough to damage the segment - so called bursting failure. According to the various design guides from UK (PAS 8810, 2016), compression stress at the joint surface can generate bursting failure of the segment. This is normally from the TBM's jacking force applied at the circumferential joint, and the lining's hoop thrust generated from the permanent loads applied at the radial joint. Therefore, precast concrete segment lining's joints shall be designed to have sufficient structural capacity to resist bursting stresses generated by the TBM's jacking force and by the hoop thrust. In this study, bursting stress at the segment joints are calculated, and the joint's structural capacity was assessed using Leonhardt (1964) and FEM analysis for three different design cases. For those three analysis cases, hoop thrust at the radial joint was calculated with the application of the most widely used limit state design codes Eurocode and AASHTO LRFD (2017). For the circumferential joints bursting design, an assumed TBM jack force was used with considering of the construction tolerance of the segments and the eccentricity of the jack's position. The analysis results show reinforcement is needed as joint bursting stresses exceeds the allowable tensile strength of concrete. This highlights that joint bursting check shall be considered as a mandatory design item in the limit state design of the segment lining.

Comparison of Domestic and Foreign Design Standards for Overall Stability of Soil Nailed Slopes (쏘일네일 보강 비탈면의 전체 안정성에 대한 국내외 설계기준 비교)

  • Kim, Tae-Won;You, Kwang-Ho
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.6
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    • pp.5-13
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    • 2019
  • The international trend in soil nailed wall design has been evolved from the allowable stress design to limit state design and it is still currently ongoing. The design guidelines in Korea and Hong Kong still adopts the allowable stress design philosophy while those in others mostly do the limit state design. In this study, four soil nail design methods presented in the major design guidelines (U.S. FHWA GEC 7 (2015), Clouterre in France (1991), Soil nailing - best practice guidance in U.K. (CIRIA, 2005), Geoguide 7 in Hong Kong (2008) and Design standard for slope reinforcement work in Korea (KDS 11 70 15 f: 2016)) are described and analyzed in brief. The factor of safety and CDR (Capacity-to-Demand Ratio) which is used to measure the degree of conservatism of a design guide are obtained for the two cases. One is the design example presented in CIRIA (2005) and the other is in-situ loading test performed on the top of backfill of the soil nail wall to investigate the conservatism of design guidelines. It is revealed that the design method in overall stability of soil nail walls in domestic design method (CDR=0.78) is the most conservative and those by Clouterre (CDR=0.99, 1.09), Geoguide 7 (CDR=1.13, 0.97), U.S. FHWA (CDR=1.09, 1.07) and CIRIA (CDR=1.40, 1.16) in order from the second most conservative to the least conservative for the design example presented in CIRIA. For the in-situ loading test performed on the top of backfill of the soil nail wall, the order of conservatism is identical except that the places of Geoguide 7 (CDR=0.66, 0.72) and FHWA (CDR=0.73, 0.72) are changed. However, the results obtained among U.S. FHWA (2015) and Clouterre (1991) and Geoguide 7 (2008) are not so different.

Study of the Production Techniques Used in the Goryeo-period Gilt-Bronze Case for Acupuncture in the Collection of the Royal Museums of Art and History, Belgium (벨기에 왕립예술역사박물관 소장 고려시대 금동침통의 과학적 보존처리를 통한 제작기법 연구)

  • Lee, Jaesung;Park, Younghwan
    • Conservation Science in Museum
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    • v.27
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    • pp.147-164
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    • 2022
  • Over 200,000 Korean cultural heritage items are currently located abroad. They have made their way to 22 countries under different circumstances and with unique backgrounds. While some of them continue to contribute to promoting Korean culture around the world, others cannot be exhibited due to damage or poor condition. In view of these circumstances, the Overseas Korean Cultural Heritage Foundation (OKCHF) has since 2013 provided museums and art galleries abroad with support for the conservation, restoration, and utilization of the Korean cultural heritage items that they house. As a part of these efforts and on the occasion of the 120th anniversary of the diplomatic relationship between the Republic of Korea and the Kingdom of Belgium in 2021, a gilt-bronze case for acupuncture needles dating to the Goryeo period (918-1392) from the collection of the Royal Museums of Art and History (RMAH), Belgium was brought to Korea for conservation treatment. The primary purpose of this conservation treatment was to restore the original form of the relic and slow to the degree possible the progress of corrosion. The conservation treatment of the gilt-bronze case followed the fundamental order of conservation treatment: removal of corrosive substances, stabilization, and reinforcement. Since this was the first case of restoring metallic cultural properties under the abovementioned support program by the OKCHF, special methodologies distinct from those available in overseas institutions were required. Diverse scientific methods (e.g., X-ray inspection, CT scanning, 3D microscopy) were applied to identify the metalcraft techniques used in the Goryeo period. The analysis found that several designs, including lotus and scrollwork, were exquisitely engraved on the surface of the case by making dots using a round-edged chisel. A bronze plate engraved with designs was rolled into a cylindrical form. The ends were overlapped by 2 to 3 centimeters and then attached to each other by silver soldering. The overlapping ends were welded flat with nearly no gaps. As the final process in the production, the case was lavishly gilt with gold powder using amalgam gilding. The conservation treatment of the gilt-bronze case for acupunctural needles in the RMAH collection restored the original form of the relic and arrested further corrosion. Above all, it revived the historic and academic value of the overseas Korean cultural heritage through scientific analysis.

The Operation Plan of the Community-Linked Extracurricular Education program for Lifelong Education for the Persons with Disabilities Based on the Memorandum of Understanding (MOU) of Extracurricular Education between Chosun University and Daegu University (조선대학교-대구대학교 비교과 교육 업무협약(MOU) 기반 지역 연계 장애인평생교육 비교과프로그램 운영 방략)

  • Kim, Young-Jun;Kim, Wha-Soo;Rhee, Kun-Yong
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.2
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    • pp.273-280
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    • 2022
  • Based on the MOU between Chosun University and Daegu University, this study was conducted with the aim of exploring the operation strategy of a extracurricular education program on the theme of lifelong education for the disabled in community connection. In front-line university sites, extracurricular education programs are often recognized as forms and procedures to assist in subject learning at the major or liberal arts level, but they have a very important status and identity considering that they are classified as "learning competency reinforcement support", "career psychological counseling support", "employment and start-up support", "subject-linked extracurricular education". Accordingly, the extracurricular education programs has the nature and advantage of covering not only the level of the one-time trend program itself, but also various community -linked problem-solving learning, including students' major learning and employment linkage. As part of the above, this study aims to present a strategy for the operation of a extracurricular education programs with the main theme and content of "lifelong education for the disabled" by viewing Chosun University and Daegu University. The contents of the study were largely presented as "organizational operation strategy between two universities," "operation strategy of curriculum between two universities," and "comprehensive system for extracurricular education programs operation of lifelong education for the disabled between the two universities". First, the first research content, "Organized Operation Strategy between Two Universities," was schematized in detail the process of collaborating and communicating with Chosun University's center of extracurricular activities, Daegu University Lifelong Education Center, and other committees and departments. The second research content, "The Curriculum Operation Strategy between Two Universities", is a detailed schematic diagram of the learning contents, methods, and procedures to be organized in the extracurricular education program. The third study, "Comprehensive System of extracurricular education program Operation for Lifelong Education for the Disabled between Two Universities," presents the results of synthesizing the basis elements essential for operating the extracurricular education program at the level of a roadmap. As a result of the study, it was possible to see the project tasks that could be promoted in-depth through the operation of a extracurricular education program on lifelong education for the disabled through the MOU between the two universities.