• Title/Summary/Keyword: restoration material

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Relationship between Stiffness of Restorative Material and Stress Distribution for Notch-shaped Non-carious Cervical Lesions

  • Kim, Kwang-Hoon;Park, Jeong-Kil;Son, Kwon
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.3
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    • pp.64-67
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    • 2008
  • This study investigated the influence of composite resins with different elastic moduli and occlusal loading conditions on the stress distribution of restored notch-shaped non-carious cervical lesions (NCCL) using 3D finite element analysis. Two different materials, Tetric Flow and Z100, were used as representative flowable hybrid resins for the restoration of NCCL. A static point load of 500 N was applied at the buccal and palatal cusps. The ratios of stress reduction to energy dissipation were better in the compressive state than the tensile state regardless of the restorative material. The total dissipation ratios for Tetric Flow were 1.5% and 4.2% larger than those for Z100 under compression and tension, respectively. Therefore, tensile stress poses more of a risk for tooth fracture, and Tetric Flow is a more appropriate material for restoration.

Development of a Smooth Colon Surface Restoration Method for Electronic Colon Cleansing (전자적 장세척을 위한 부드러운 장표면 복원 방법 개발)

  • Kim, Seung-Hwan;Kim, Dong-Sung
    • Journal of Biomedical Engineering Research
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    • v.32 no.3
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    • pp.251-256
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    • 2011
  • Virtual colonoscopy is favored over conventional colonoscopy because its non-invasive procedure can avoid complications that may happen in a conventional approach and because it can cleanse colon electronically instead of uncomfortable conventional colon cleansing. Electronic Colon Cleansing(ECC) has to deal with not only removing tagged fecal material but also recovering Partial Volume Effect(PVE) due to tagging material. This paper proposes an ECC method restoring inherent natural PVE while previous approaches focused only on reducing PVE due to tagged fecal material. The proposed method reduces PVE using 3-dimensional adaptive density correction and then replaces tagged fecal material into air. Next, it generates natural PVE for the replaced air adjacent to soft tissue and finally makes smooth transition of gray values for soft tissue adjacent to the replaced air. The proposed method applied to eleven patient data, and showed promising results.

Filed Applicability Evaluations of Restoration Material for Underground Cavities Formed by Ground Subsidence (지반침하로 인한 지하공동 복구재료의 현장적용성 평가)

  • Bang, Seongtaek;Baek, Seungju
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.3
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    • pp.5-11
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    • 2020
  • Recently, ground pits that have been occurring frequently in urban areas are hindering traffic flow and causing property damages and loss of human life, acting as factors that are threatening the safety of citizens. Therefore, sunken ground must be quickly restored and provisions must be made for additional damage but current domestic detailed standards regarding ground pits and accurate definitions regarding causes and measures to be taken for reoccurrences are lacking. Restoration methods of sunken ground include backfilling by reusing sunken soil or other fill material and paving the road and while this is the most often used method, this only prevents ground from sinking temporarily and can not serve as a fundamental solution. Also, additional ground pits can occur on ground that is reinforced using this method due to faulty backfill material or faulty hardening. This study used Eco-friendly High-Strength Material (EHSM) as restoration material that can be used in the restoration of underground cavities that have occurred due to ground subsidence to analyze the engineered characteristics of modified dredging clay and test pieces made from changed ratios of EHSM and weathered granite soil were uniaxial compression tests were conducted and freezing-thawing tests were conducted to study strength properties according to environmental changes of restoration material, and after tests were concluded by each level, uniaxial compression tests and dynamic elasticity tests were conducted for intensity analysis. Also, to evaluate strength characteristics of the restored ground, dynamic plate load tests were conducted to verify the improvement effectiveness of the restored ground.

Hearing Restoration Operation (청력증진술)

  • 소진명;김형곤;전승하
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1979.05a
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    • pp.3.1-3
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    • 1979
  • The aim of ear operation is to cease otorrhea and to restore hearing. The ceasation of otorrhea and the graft of tympanic membrane are reached to successful stage, and yet hearing restoration process still remains further to need a matter of development. Authors carried out 67 cases hearing restoration operation among 154 patients who had been undertaken mastoid-tympanoplasty during period of Feb. 1978 through March 1979. 54 cases have been followed for this study among 67 cases hearing restoration operation. The used material of operation are almostly incus and some cases with TORP. This paper is dealing with its surgical method and postoperative audimetric study.

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Evaluation of Railroad Restoration Technology using Quick-reaction Expansible Resins (급속 팽창성 수지를 이용한 철로침하 복원공법의 평가)

  • Shin, Eun-Chul;Son, Won-Ik;Kim, Sung-Hwan;Kan, Hyoun-Hoi
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1789-1795
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    • 2007
  • Railroad, the structure maintenance and restoration project was increased and widely performed in concrete pavement road and airport, building at downtown area, bridge abutment, and other concrete structures. Especially, the ground reinforcement technique by quick-reaction expansible resins is the most effective countermeasures against differential settlement and undesired deformation of structure. In this paper, the unconfined compressive strength and some environmental related tests were conducted to evaluate compressive strength and environmental effect of quick-reaction expansive resins and soil mixtures. Also, three case histories of concrete structure and railroad restoration project are presented. Based on the laboratory test, the quick-reaction expansible resins and soil mixture represent the sufficient compressive strength and the leachate material is satisfied the environmental regulation limits. As a result of this study, the structure restoration technology using quick-reaction expansible resins is very effective for restoration of differential settlement and deformation, and it is environmentally sustainable technology.

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Evaluation of the effects of the river restoration in Hwangji Stream, the upstream reach of the Nakdong River

  • Bong Soon Lim;Jaewon Seol;Chang Seok Lee
    • Journal of Ecology and Environment
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    • v.48 no.1
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    • pp.85-95
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    • 2024
  • Background: In Korea, riparian zones and some floodplains have been converted into agricultural fields and urban areas. However, there are essential for maintaining biodiversity, as they are important ecological spaces. There are also very important spaces for humanity, as they perform various ecosystem services in a changing environment including climate change. Due to the importance of rivers, river restoration projects have been promoted for a long time, but their achievement has been insignificant. Development should be pursued by thoroughly evaluating the success of the restoration project. Ecological restoration is to accelerate succession, a process that a disturbed ecosystem recovers itself, with human assistance. Ecological restoration can be a test bed for testing ecological theories in the field. In this respect, ecological restoration should go beyond a 'simple landscaping exercise' and apply ecological models and theories in restoration practice. Results: The cross-section of the restored stream is far from natural rivers due to its steep slope and artificial material. The vegetation profiles of the restored streams did not reflect the flooding regime of the river. The species composition of the vegetation in the restored stream showed a significant difference from that of the reference stream, and was also different from that of an unrestored urban stream. Although species richness was high and the proportion of exotic species was low in the restored stream, the effect was offset by the high proportion of gardening and landscaping plants or obligate terrestrial plants. Conclusions: Based on both the morphological and ecological characteristics of the river, the restoration effect in the restored stream was evaluated to be very low. In order to solve the problems, a systematic adaptive management plan is urgently required. Furthermore, it is necessary to institutionalize the evaluation of restoration effects for the development of river restoration projects in the future.

Analysis on the Quarry Restoration Methods in Hong Kong (홍콩의 채석장 식생복원공법에 관한 분석)

  • Park, Chong-Min;Lee, Joon-Woo;Youn, Ho-Joong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.5
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    • pp.121-132
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    • 2009
  • The agency which is responsible for work related to the restoration of vegetation on the quarry in Hong Kong is the Geotechnical Engineering Office of Civil Engineering and Development Department (CEDD). CEDD's environmental management system was certified as ISO 14001 : 2004 in 2006 and diverse instructions and technical documents about the restoration of the quarry were published and used for the performance of work and the implementation of the project. The restoration of the quarry is being carried out to respond to short-term and long-term goals. The general instructions for the restoration of vegetation says that a plant, when selected, should be self-sustainable with minimum maintenance required, have a high growth and survival rate, be tall enough to cover the rock slope faces, and preferably produce colourful flowers. These instructions prescribe the vegetation introduction technology, planting seasons, structural material of the vegetation works, maintenance and management, tree nursery operation, means of water supply, etc. This report introduced the outline of work on restoring vegetation carried out at Anderson Road, Shek O, Lam Tei, Turret Hill, Lamma, all large-sized quarries. In addition, it additzed Anderson Road's master plan. It is hoped that the Hong Kong examples so introduced are referred to in terms of institutional and technical considerations related to the nation's project for restoring quarries.

A study on the development and the physical properties of Epoxy Putty for earthenware restoration (토기 복원용 Epoxy Putty 개발 및 물성에 관한 연구)

  • Bae, Jin Soo;Cheong, Da Som;Kim, Woo Hyun;Kang, Seok In;Wi, Koang Chul
    • Journal of Conservation Science
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    • v.30 no.1
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    • pp.103-109
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    • 2014
  • This study aimed to develop materials to compensate for problems of restoration for lost parts and material problems in the conservation treatment. First, there are several problems with existing materials as follows: secondary damage due to the high shrinkage rate and low adhesive strength, sense of difference due to the severe yellowing, remelting due to irreversibility of materials, processability due to the high strength, sag due to the prolonged setting time in the work process and surface contamination of artifacts due to tools or gloves. In order to solve these problems, this study set developmental goals after understanding the types and physical properties based on epoxy resin among the currently used restoration materials of pottery and earthenware. The developed epoxy resin is epoxy putty, which is cured within 5 minutes, for earthenware restoration. In the earthenware restoration method, the epoxy putty enhanced the workability by quickly curing in paste form and compensated disadvantages such as surface contamination. In addition, the use of white micro-balloon for the epoxy stock solution made coloring easier and weight lighter, and a restoration material with low shrinkage and superior processability was developed.

Research of Restoration Material in Pottery and Porcelain Conservation (도토기 보존처리에 사용된 복원재료 연구)

  • Yang Pil-Seung;Moon Sun-Young;Park Gi-Jung
    • 한국문화재보존과학회:학술대회논문집
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    • 2005.11a
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    • pp.179-184
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    • 2005
  • Materials used for repairing and restoring both pottery and porcelain are practically organic, which makes the analysis procedure difficult in the course of time. It is, however, important in the field of conservation to analyze the material applied in the past. In consequence, this research will examine the components of the restoration materials collected in the process of ceramic conservation: the fillings using SEM-EDS and FT-IR; retouching materials; the adhesive used between the filling and retouching material.

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A Study for Making Planting Ground and Irrigation System for Greening Artificial Ground of Planter Type (화단형태의 인공지반 녹화를 위한 식재토양조성 및 관수방안 연구)

  • Kim, Sun-Hae
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.6
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    • pp.12-18
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    • 2004
  • This study is to make plans for perpendicular greening with artificial ground of planter type to improve urban environment. The experiments of this study are performed to find out the suitable soil and irrigation method for artificial ground of planter greening. Thereupon, organic or inorganic soil improvement material is mixed with soil of each planter as experiment, In result, the plants in soil mixed organic soil improvement material thrive rather than that in soil mixed inorganic material, It is to be desired that the planter equip with the irrigation system, be wider than planter and be planted shrubs for positive plant growth. As for irrigation system, drip irrigation is effective on plant growth southern exposure but Ebb and Flow is effective eastern exposure. Therefore, irrigation system should consist of two types above plus keeping water on the bottom of planter to save water and store rainwater.