• Title/Summary/Keyword: reinforcement materials

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The Development and Acceptance of Knowledge Information in Garden of Joseon Dynasty - Focusing on the Garden and Flowering Books Compiled from the 15th and 19th Centuries - (조선시대 정원의 지식정보 전개와 수용 - 15~19세기 편찬된 정원 및 화훼 관련서적을 중심으로 -)

  • Kim, Dong-Hyun;Lee, Won-Ho
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.38 no.1
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    • pp.10-20
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    • 2020
  • This study aims to analyze the developed characteristics of the knowledge and information of gardens through garden or flowering plant books compiled in the 15th and 19th centuries of Joseon Dynasty. Diachronically analysis of the garden or flowering plant books classified the characteristics in which knowledge and information about gardens are developed by the period, and looked at the factors. The results are as follows; First, the relationship between the authors who compiled the garden or flowering plant books had similar characteristics to the genealogy of Realist School of Confucianism(實學) in the Joseon Dynasty. Kang, Hee-An's practical features influenced later realist school of confucianism scholars. Lee, Su-Gwang has accumulated knowledge of the garden through his experience of traveling the diplomatic envoy to China. Since then, Hong Man-sun's ideology has been related to Charles, a member of the Southerners. Seo Yu-gu was also able to accept Realist School of Confucianism in an integrated way through the Jungnong school's theory and interaction with the Jungsang school. Ryu, Jung-Lim's relationship with the Jungnong school emerged as he added to the 『Jeungbosanrimgyeongje(增補山林經濟)』. Second, the 『Yanghwasorok(養花小錄)』, 『Jibongyuseol(芝峯類說)』 「Hwuimok(卉木)」, 『Hangjeongrok(閑情錄)』, 『Sanrimgyeongje(山林經濟)』 「Yanghwa(養花)」, 『Jeungbosanrimgyeongje(增補山林經濟)』 「Yanghwa(養花)」, 『Hwaamsurok(花庵隨錄)』 and 『Imwongyeongjeji(林園經濟志)』 「Yewonji(藝畹志)」 contain garden plant characteristics, cultivation methods, and management methods. The 『Imwongyeongjeji(林園經濟志)』 「Seomyongji(贍用志)」, 「Iunji(怡雲志)」, 「Sangtaekji(相宅志)」 contain details on the location selection of gardens, the layout of facilities, how to create them and materials. The description of these garden or flowering plant books was found to be the most common introduction with 55 percent, followed by methodologies(42.8%), the Lichi Theory(理氣論, 15.5%), the classification(12.4%), and the convention(1.9%). Third, based on the importance of knowledge and information on gardens, the garden or flowering plant books related to the period were classified as early period, including 『Yanghwasorok(養花小錄)』, 『Jibongyuseol(芝峯類說)』 which were compiled before the 17th century. The 18th-century compiled 『Sanrimgyeongje(山林經濟)』 and 『Jeungbosanrimgyeongje(增補山林經濟)』 were classified as middle period, and the 19th-century compilation of 『Imwongyeongjeji(林園經濟志)』 was classified as late period. The garden or flowering plant books were cited the contents of ancient Chinese books, the author's experiences and opinions contained in the preceding period in later garden books. And the reinforcement of garden knowledge was made to reflect the agricultural technology and expertise developed at the time of writing. Fourth, based on analysis of the development and acceptance of knowledge information in garden by period, In the early period was dealing with floriculture as a way to explore the logic of things. Later, in the 18th century, a vast influx of garden knowledge information came from China. Among scholars, they secured justification for garden creation as part of various knowledge-seeking activities, which expanded their expertise in gardens. In response to the trend of gardening in the 19th century, professional books were written based on knowledge and information on gardens that were collected in the past, and systems were established such as the collection and management of garden plants, construction methods, enjoying methods, and self-realization.

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.

Development and Application Effect of Design-based STEAM Program for Boosting the Career Consciousness of 5~6th Grade Elementary School Students for Natural Sciences and Engineering (이공계 진로의식 신장을 위한 초등 5~6학년용 설계기반 미래 유망직업 STEAM 프로그램 개발 및 적용 효과)

  • Lim, Yoo-Na;Min, Bu-Ja;Hong, Hoo-Jo
    • Journal of The Korean Association For Science Education
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    • v.35 no.1
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    • pp.73-84
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    • 2015
  • In this research, two careers connectable with the contents of the curriculum of fifth to sixth grade elementary school students were selected among other promising future careers in biotechnology and medical engineering fields. 'Design-based promising future career STEAM program' was developed and its validity and effectiveness were verified. Reflecting recent issues, and complying with the STEAM standard (frame) instructional materials were developed through group deliberations for nine months, based on the achievement standards through an analysis of subject curriculum revised in 2009. This was prepared so that students are able to experience biotechnology and medical engineering related careers in a simulational form emphasized with creative design to make them prefer natural sciences and engineering careers and draw their interests and recognition of the relevant careers under the two disciplines. As a result of such application to STEAM Leader School students at the verification stage of the program, the contents and level of the program were verified suitable, receiving favorable reviews. And as a result of applying the developed program on other elementary school students, it was discovered that significant improvements were found in their career consciousness. Through this research, it was suggested that there is a need for a simplification of the curriculum content standards, a provision of 'standard for integration,' development of teachers' ability in reconstituting or organizing the STEAM and proceeding classes, continuous long-term support to see the effects of a policy or a program, and a reinforcement of career education integrated in the curriculum.

An Evaluation of Food Safety Sanitation Management Practices of Food Manufacturing Companies that Supply Foods to School Foodservice (학교급식 식재료 제조.가공업체의 위생관리 실태 조사)

  • Kim, Yun-Hwa;Lee, Yeon-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.10
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    • pp.1535-1544
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    • 2010
  • This study was conducted to evaluate the sanitation management practices in food manufacturing companies that supply food and food ingredients to school foodservice operations. Subjects consisted of 34 food manufacturing factories located in the Daegu and Gyeongbuk areas. Sanitation performance was self-evaluated using a Likert 5-point scale. The total mean score for factory sanitation performance was 4.72. Scores for perceived sanitation management performance in the factories were as follows: management of material (4.90); personal hygiene (4.78); management of work (4.71); management of workplace and vicinity (4.68); and food and raw material transportation (4.67). Participating companies that had HACCP certification programs scored high on the following sanitation inspection items: washing and sanitation guides, adequate equipment for correct hand washing, and sanitation of raw material delivery vans. The mean frequency for employee sanitation education was 2.8 times per month. Factory managers believed that their sanitation management programs kept their food safe and that the food was produced and delivered with a high degree of safety. However, they thought that food sanitation standardization was needed in order to supply high-quality and safe food items. In terms of traceability, 58.8% of the raw materials were traceable and 61.8% of the manufactured products were traceable. Sanitation management performance scores for the participating food manufacturing companies were high, although the soybean sprouts processing companies had comparatively low scores. Management reinforcement of employee sanitation education and a sense of duty and pride among factory employees will promote adequate and appropriate sanitation management performance for food safety and quality in factories that supply food and ingredients to school foodservice operations.

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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Structural Behavior of the Buried flexible Conduits in Coastal Roads Under the Live Load (활하중이 작용하는 해안도로 하부 연성지중구조물의 거동 분석)

  • Cho, Sung-Min;Chang, Yong-Chai
    • Journal of Navigation and Port Research
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    • v.26 no.3
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    • pp.323-328
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    • 2002
  • Soil-steel structures have been used for the underpass, or drainage systems in the road embankment. This type of structures sustain external load using the correlations with the steel wall and engineered backfill materials. Buried flexible conduits made of corrugated steel plates for the coastal road was tested under vehicle loading to investigate the effects of live load. Testing conduits was a circular structure with a diameter of 6.25m. Live-load tests were conducted on two sections, one of which an attempt was made to reinforce the soil cover with the two layers of geo-gird. Hoop fiber strains of corrugated plate, normal earth pressures exerted outside the structure, and deformations of structure were instrumented during the tests. This paper describes the measured static and dynamic load responses of structure. Wall thrust by vehicle loads increased mainly at the crown and shoulder part of the conduit. However additional bending moment by vehicle loads was neglectable. The effectiveness of geogrid-reinforced soil cover on reducing hoop thrust is also discussed based on the measurements in two sections of the structure. The maximum thrusts at the section with geogrid-reinforced soil cover was 85-92% of those with un-reinforced soil cover in the static load tests of the circular structure; this confirms the beneficial effect of soil cover reinforcement on reducing the hoop thrust. However, it was revealed that the two layers of geogrid had no effect on reducing the overburden pressure at the crown level of structure. The obtained values of DLA decrease approximately in proportion to the increase in soil cover from 0.9m to 1.5m. These values are about 1.2-1.4 times higher than those specified in CHBDC.

A Diagnostic Analysis on the Conservation Status for the Maintenance of the Front Wall of Jungjeongdang Area of Dodong-Seowon (도동서원 중정당 전면 담장의 보수를 위한 진단학적 보존 상태 분석)

  • Kim, Kyu-Yeon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.1
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    • pp.1-11
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    • 2019
  • This study was conducted to analyze the conservation status by diagnostical methology for the front wall of Jungjeongdang area of Dodong-Seowon. The study was carried out as photogrammetry and mapping - investigation of materials and conservation status - analysis and evaluation of conservation status. The results are as follows. First, in the case of photogrammetry, each photograph was took in superposition, and the distortions of the photographs were corrected and synthesized. Based on this, actual survey drawings of the wall were prepared. Second, in case of material and conservation status, the wall is in the form of Wapyeondam and the material of the head part are tile, mud and lime, and the material of the body part are mud and tile. The mud was mixed with gravel, sand and straw. At the base part, amorphous natural stones and mud were used. The remarkable damage that appears on the wall is erosion of the base part, and some disintegration appears in the body part. There is a biological patina on the head and the base, and vegetation such as lichen is concentrated on the partial body. There was superficial deposit in the head part, and some tiles were broken or lost. Deep fissures are intensively located in some part of the eastern wall. Third, in the case of analysis and evaluation of the conservation status, it is considered that by the erosion of the foundation part and the disintegration of the body part, there is a possibility that physical damage will continue to be applied to the wall, so immediate action is necessary. The distribution of biological patina and vegetation does not appear to cause great problems in the wall, but it is necessary to reduce it in view of aesthetic problems. A cracked or missing tile would need to be replaced, and deep cracks in the eastern wall appear to have been caused by subsidence, and reinforcement of the underground is necessary to prevent further damage.

Surgical Treatment of Osteoporotic Vertebral Compression Fractures at Thoraco-Lumbar Levels: Only Pedicle Screw Constructs with Polymethylmethacrylate Augmentation (흉요추부 골다공증성 척추 압박 골절의 수술적 치료: 골시멘트 보강술을 이용한 척추경 나사 고정)

  • Jun, Deuk Soo;Baik, Jong-Min;Park, Ji Hyeon
    • Journal of the Korean Orthopaedic Association
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    • v.54 no.4
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    • pp.327-335
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    • 2019
  • Purpose: To investigate the radiological efficacy of polymethylmethacrylate (PMMA) augmentation of pedicle screw operation in osteoporotic vertebral compression fractures (OVCF) patients. Materials and Methods: Twenty OVCF patients, who underwent only posterior fusion using pedicle screws with PMMA augmentation, were included in the study. The mean follow-up period was 15.6 months. The demographic data, bone mineral density (BMD), fusion segments, number of pedicle screws, and amount of PMMA were reviewed as medical records. To analyze the radiological outcomes, the radiologic parameters were measured as the time serial follow-up (preoperation, immediately postoperation, postoperation 6 weeks, 3, 6 months, and 1 year follow-up). Results: A total of 20 patients were examined (16 females [80.0%]; mean age, 69.1±8.9 years). The average BMD was -2.5±0.9 g/cm2. The average cement volume per vertebral body was 6.3 ml. The mean preoperative Cobb angle of focal kyphosis was 32.7°±7.0° and was improved significantly to 8.7°±6.9° postoperatively (p<0.001), with maintenance of the correction at the serial follow-up, postoperatively. The Cobb angle of instrumented kyphosis, wedge angle, and sagittal index showed similar patterns. In addition, the anterior part of fractured vertebral body height averaged 11.0±5.0 mm and was improved to 18.5±5.7 mm postoperatively (p=0.006), with maintenance of the improvement at the 3-month, 6-month, and 1-year follow-up. Conclusion: The reinforcement of pedicle screws using PMMA augmentation may be a feasible surgical technique for OVCF. Moreover, it appears to be appropriate for improving the focal thoracolumbar/lumbar kyphosis and is maintained well after surgery.

Analysis and Conservation of Sheet Music Featuring the National Anthem of Korea with Lyrics in Korean, Chinese, and English - Focusing on Light Blue Pigment Analysis and Conservation Treatment - (한중영문중국판 한국애국가 악보의 분석 및 보존 - 밝은 청색안료 분석과 보존처리를 중심으로 -)

  • BAE Subin;PARK Serin;LEE Hanhyoung;JEONG Heewon
    • Korean Journal of Heritage: History & Science
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    • v.57 no.3
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    • pp.104-114
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    • 2024
  • Sheet Music of the National Anthem of Korea with Lyrics in Korean, Chinese, and English is a four-sided sheet of paper folded in half. It was first introduced to Korea on November 12, 1945, by Kim Ku, the president of the Provisional Government. The sheet music was published in three languages and is a valuable document for researching the evolution of the anthem and its history. Although it was published in large quantities at the time, it is currently known as the only in Korea and has been designated and managed as a national registered heritage. The sheet music was not significantly damaged, but discoloration and physical damage suggested raised the need for conservation treatment. A pre-treatment examination of the conservation condition revealed that the artifact was received on archival film and had been folded in half for many years, leaving it vulnerable to tears at the top and bottom of the folds and partial wear and tear at the edges. In addition, the pigments used on both sides of the sheet had discolored and transferred to the opposite side. Portable X-ray fluorescence (XRF) analysis was conducted to investigate the pigments used in the sheet music cover, specifically focusing on red, black, and light blue pigments. Titanium (Ti) was detected in the light blue pigment, characterized by a powdery coloring layer. The remaining colors in the printed form were difficult to sample and could not be analyzed further. The light blue sample underwent additional analysis using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and Raman spectroscopy. Cross-validation of the results with the artifact's historical context suggested that the bright blue color observed in the 1945 sheet music is likely due to the use of anatase white pigment, rather than rutile. Furthermore, the bright blue pigment is believed to be a blend of phthalocyanine blue, a synthetic pigment introduced in 1936. Fiber analysis revealed longitudinal striations in the hemp fibers and twists in the cotton fibers, suggesting that the paper was made from a mixture of cotton and hemp fibers. Based on the findings of the condition survey, the conservation treatment for the artifact focused on minimizing moisture to avoid stressing the paper and reinforcing the physically vulnerable areas. The reinforcement paper was dyed to match the base of the artifacts, pre-coated repair paper was used for conservation, and appropriate folders and boxes were made for storage after treatment. This study is expected to serve as an important foundational resource on the materials used in modern and contemporary records.