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Effect of adhesive hydrophobicity on microtensile bond strength of low-shrinkage silorane resin to dentin (접착시스템의 소수성이 Low-shrinkage silorane resin과 상아질의 미세인장강도에 미치는 영향)

  • Cho, So-Yeun;Kang, Hyun-Young;Kim, Kyoung-A;Yu, Mi-Kyung;Lee, Kwang-Won
    • Restorative Dentistry and Endodontics
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    • v.36 no.4
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    • pp.280-289
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    • 2011
  • Objectives: The purpose of this study was to evaluate ${\mu}TBS$ (microtensile bond strength) of current dentin bonding adhesives which have different hydrophobicity with low-shrinkage silorane resin. Materials and Methods: Thirty-six human third molars were used. Middle dentin was exposed. The teeth were randomly assigned to nine experimental groups: Silorane self-etch adhesives (SS), SS + phosphoric acid etching (SS + pa), Adper easy bond (AE), AE + Silorane system bonding (AE + SSb), Clearfil SE bond (CSE), CSE + SSb, All-Bond 2 (AB2), AB2 + SSb, All-Bond 3 (AB3). After adhesive's were applied, the clinical crowns were restored with Filtek LS (3M ESPE). The 0.8 mm ${\times}$ 0.8 mm sticks were submitted to a tensile load using a Micro Tensile Tester (Bisco Inc.). Water sorption was measured to estimate hydrophobicity adhesives. Results: ${\mu}TBS$ of silorane resin to 5 adhesives: SS, 23.2 MPa; CSE, 19.4 MPa; AB3, 30.3 MPa; AB2 and AE, no bond. Additional layering of SSb: CSE + SSb, 26.2 MPa; AB2 + SSb, 33.9 MPa; AE + SSb, no bond. High value of ${\mu}TBS$ was related to cohesive failure. SS showed the lowest water sorption. AE showed the highest solubility. Conclusions: The hydrophobicity of adhesive increased, and silorane resin bond-strength was also increased. Additional hydrophobic adhesive layer did not increase the bond-strength to silorane resin except AB2 + SSb. All-Bond 3 showed similar ${\mu}TBS$ & water sorption with SS. By these facts, we could reach a conclusion that All-Bond 3 is a competitive adhesive which can replace the Silorane adhesive system.

A Study on the Characteristics of Vegetation Landscape of Fortress of Jeonju District in Represented on the (<전주지도>에 표현된 조선 후기 전주부성의 식생경관상)

  • Kang, In-ae;Rho, Jae-hyun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.36 no.2
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    • pp.1-10
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    • 2018
  • This study aims to find out the characteristics of the vegetation landscape characteristics and system which led the formation of the urban image in Jeonju in the late Joseon period connected with urban spatial structure, using designated as treasure No. 1586 which was made in the middle of 18C. The vegetation landscape characteristics of Jeonju in the late Joseon Dynasty derived from the analysis of are summarized as follows. Firstly, the vegetation landscape system in Jeonju is composed of the natural vegetation around mountain area of Jeonju-Buseong, the independent vegetation or cluster planting forests linked with the main facilities, the Bibo-Forests connected with topographical characteristics of Jeonju, and the vegetation combined with a private garden. Secondly, planting landscape was specialized using flag species and local species. Thirdly, the garden-type plantation centered on the back yard or front of main facilities, with the background of natural vegetation landscape combined with the mountain area and the vegetation combined with a private garden, dominates vegetation landscape of Jeonju Buseong as objects. Fourthly, in order to overcome the defects of topographical characteristics, the Bibo-Forests were emphasized as an important planting landscape element in addition to the vegetation landscape elements connected with main facilities. Fifth, ecological vegetation landscape technique was taken considering the topographical characteristics. The characteristics of vegetation landscape of Jeonju Buseong, which is derived from , have an important meaning to restore and reproduce Jeonju's historical features. Especially, the vegetation communities of the non-booming concept combined with the geographical features, the ecological landscape harmonizing with the topography, the round house type landscape mixed with the private house, and the specialization of vegetation landscape using local species are important factors in securing the city image based on the historical characteristics and creating a city brand that utilizes vegetation landscape.

A Study on the Characteristics of Yuyin ShanFang in China Lǐngnán Region (중국 영남지방 여음산방 원림의 특징에 관한 연구)

  • Shi, Shi-Jun;Ahn, Gye-Bog
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.36 no.3
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    • pp.48-57
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    • 2018
  • In this study, we conducted an analysis on the actual field materials and the ancient text of January 2017. First, Yuyin ShanFang is one of the famous garden in the Lingnan Region, and its total area is $1598m^2$. Wobin called the name 'Yuyin(餘蔭)' meaning the virtues of his ancestors. Second, if we analyze the poem written by Wobin, we can classify it as a phrase expressing the world beyond the future, a poem expressing the ideas of family and romantic ideas. Third, the space spread to the south around the shrine building in the middle of the site was largely a residential space, according to the analysis of the site's layout and spatial composition. Fourth, the spatial component of the hydronic acid is analyzed. The pavilion area is the Hanchwi-Pavilion, which is designated in the Wongrim, and Gyesang-Pavilion, which is a unique range that describes the peak of the garden. Fifth, Yuyin ShanFang has five ponds that are very diverse in shape. It is characteristic of us to stand on a technical boundary. Sixth, Seokgasan was referred to as Gyeongbansan, which was named after The builder Wobin and his descendants who passed it. Seventh, Hwachang is characterized by a wooden bull window and a compound glass. Eighth, the alumni style is not as diverse as the alumni style of the Suzhou traditional garden, but it features various forms and colorful pictures on the front of the alumni. Ninth, the one-piece sculptures of the interior of a building are expressed themes such as Gilsang, Sukjeong, Daoism, Palseom, and others. Finally, Trees planted in Yuyin ShanFang are mostly tropical plants, and some of them have symbolic meaning. Because the weather here is good for growing fruit, so planted a lot of fruit trees.

A Study on the Manual Skills of Experimental Apparatuses of Preservice Elementary School Teachers (초등 예비교사의 실험 기구 조작 능력에 대한 연구)

  • Lee, So-Ree;Choi, Hyun-Dong;Lim, Jae-Keun;Shin, Se-Young;Yang, Il-Ho
    • Journal of Science Education
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    • v.35 no.1
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    • pp.80-90
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    • 2011
  • The purpose of this study is to investigate manual skills of experimental apparatuses of pre-service elementary school teachers by examining and analyzing the process of experiments conducted by pre-teachers. For this study, 24 pre-service elementary school teachers were selected as the subjects and 4 experimental apparatuses were chosen through analyzing science textbooks from 3rd grade to 6th grade in elementary school. The selected experimental apparatuses were alcohol burner, dropper, microscope, instruments for making a prepared specimen. In addition, a task was carefully chosen to conduct an investigation in real settings and a series of evaluation standards was developed. While 3 subjects conducted experiments in separated and independent space at the same time, 3 collaborators observed the experiment process and recorded whether the subject met the evaluation standards or not, using O, X. The study suggests that pre-service elementary school teachers' manual skills of experimental apparatuses were under far below our projections. Particularly, in case of alcohol burner, the subjects showed lower ability to properly light the burners - which is to brush through the lampwick with fire - and to adjust the height of tripods according to the flame. Also, when it comes to dropper, they were not held the way they were supposed to be. In addition, when designing prepared specimen, the subjects used their hands instead of tweezers and often skipped the process of dripping water drop and wiping water with an oilpaper. Moreover, they did not know how to use a microscope properly so there were many times that they could not focus a microscope, failing to observe the objects. Educational implications are discussed.

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Variation of Rice Production for Two Decades before and after Breeding Tongil Variety in Korea (수도 통일품종 육성보급 전후 20년간의 생산성 변이)

  • Eun-Woong Lee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.3
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    • pp.183-192
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    • 1982
  • The variability of rice productivity during last 2 decades (1961-1980) of ten years before and after the introduction of"Tongil" was reviewed from the epochal, regional and varietal points of view. During that period the cultivated area of paddy rice have remained almost unchanged, while the total rice production have got elevated from 3, 463 million metric tons in 1961 to 6.006 million metric tons in 1977, recording 73.4% increase. This remarkable increase in rice production is considered to be attributable much to the development and release of new high yielding variety, "Tongil", coupled with the amelioration of cultural techniques. However, in 1978 Tongil type varieties experienced the epidemic outbreak of blast disease due to the shifted race population of blast fungus and in 1980 recorded poor rice production as low as in 1960's due to the unfavorable weather stress throughout the rice growing season, giving rise to many problems awaiting solutions for securing the stabilized high production of rice. The rice yield has continued the gradual increase during last two decades but its difference between farmer and research organization have got wider from 79kg/10a during 1960 to 1971 to 101kg/l0a during 1972 to 1980, and also the inter-regional differences have been increased from 50-60kg/10a to 80kg/10a during those periods. Therefore, this proves that we have raised the upper boundary of rice yield by increasing the yield potential of rice variety but have not changed those absolute deviations. Estimates indicate that the increased rice production during that period was indebted 40 percent to the varietal improvement and 13 percent to the ameliorated agro-technologies, and the rest, 47 percent, could be ascribed to the other factors besides varieties and cultural technologies such as the improved agricultural environments, etc. Of course, even though it cannot be expected to unify the cultural environments and the cultural technologies, provided that much efforts are to be endeavored to minimize the yield difference of 20 percent between farmer and research organizations and the inter-regional yield difference of 20 percent, much increased rice production can be expected to be achieved with the current level of cultural technology and the yielding potential of the present rice varieties. In order to expedite the above effects on rice production the followings are to be put into practices consitently and steadfastly. 1. Reinforcement of breeding for varieties with high yielding potential and less susceptible to climatic-stress and pests, and of basic physicoecological studies of rice plant for improving the cultural technologies. 2. Continuous endeavor to secure the stabilized cultural environments by improving the soil fertility and increasing the drainage and irrigation facilities. 3. Political back-up to encourage the farmers' incentives for production 4. Precise surveys for agricultural statistics to facilitate the long-term planninge long-term planning.

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Using Effective Temperatures to Determine Safety Cultivation Season in Direct Seeding Rice on Dry Paddy (작물생육 유효기온 출현시기를 이용한 건답직파 벼의 지역별 안전작기 설정)

  • 최돈향;윤경민;윤성호;박무언
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.6
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    • pp.666-672
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    • 1997
  • Twenty years' daily mean air temperature data was used to calculate the critical early seeding date(CESD), the optimum heading date(OHD), the critical late heading date for stable ripening(CHDR) and the critical late ripening date(CLRD) for rice seeded on dry paddy in different agroclimatic zones in Korea. The CESD was defined as the first day with mean air temperature of 13$^{\circ}C$, and the OHD as the first day of the 40 consecutive days with mean air temperature of 22$^{\circ}C$ or above after heading. The CHDR was defined as the date after which the cumulative daily mean air temperature would be at least 76$0^{\circ}C$. Lastly, the CLRD was defined as the last day when daily mean air temperature remains above 15$^{\circ}C$. This information was used for the estimation of periods from the earliest date of seeding to optimum heading date, the latest possible date of heading and the latest possible date of ripening in respective regions. For instance, in Suwon, those respective periods mentioned were found to be 104days, 124days, and 165days.

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$CO_2$ Transport for CCS Application in Republic of Korea (이산화탄소 포집 및 저장 실용화를 위한 대한민국에서의 이산화탄소 수송)

  • Huh, Cheol;Kang, Seong-Gil;Cho, Mang-Ik
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.13 no.1
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    • pp.18-29
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    • 2010
  • Offshore subsurface storage of $CO_2$ is regarded as one of the most promising options to response severe climate change. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources, to transport to the storage sites and to store $CO_2$ into the offshore subsurface geological structure such as the depleted gas reservoir and deep sea saline aquifer. Since 2005, we have developed relevant technologies for marine geological storage of $CO_2$. Those technologies include possible storage site surveys and basic designs for $CO_2$ transport and storage processes. To design a reliable $CO_2$ marine geological storage system, we devised a hypothetical scenario and used a numerical simulation tool to study its detailed processes. The process of transport $CO_2$ from the onshore capture sites to the offshore storage sites can be simulated with a thermodynamic equation of state. Before going to main calculation of process design, we compared and analyzed the relevant equation of states. To evaluate the predictive accuracies of the examined equation of states, we compare the results of numerical calculations with experimental reference data. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the captured $CO_2$ mixture contains many impurities such as $N_2$, $O_2$, Ar, $H_{2}O$, $SO_{\chi}$, $H_{2}S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification and transport processes. This paper analyzes the major design parameters that are useful for constructing onshore and offshore $CO_2$ transport systems. On the basis of a parametric study of the hypothetical scenario, we suggest relevant variation ranges for the design parameters, particularly the flow rate, diameter, temperature, and pressure.

Geochemistry of Geothermal Waters in Korea: Environmental Isotope and Hydrochemical Characteristics I. Bugok Area (한반도 지열수의 지화학적 연구: 환경동위원소 및 수문화학적 특성 I. 부곡 지역)

  • Yun, Seong-Taek;Koh, Yong-Kwon;Kim, Chun-Soo;So, Chil-Sup
    • Economic and Environmental Geology
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    • v.31 no.3
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    • pp.185-199
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    • 1998
  • Hydrogeochemical and environmental isotope studies were undertaken for various kinds of water samples collected in 1995-1996 from the Bugok geothermal area. Physicochemical data indicate the occurrence of three distinct groups of natural water: Group I ($Na-S0_4$ type water with high temperatures up to $77^{\circ}C$, occurring from the central part of the geothermal area), Group II (warm $Na-HCO_{3}-SO_{4}$ type water, occurring from peripheral sites), Group III ($Ca-HCO_3$ type water, occurring as surface waters and/or shallow cold groundwaters). The Group I waters are further divided into two SUbtypes: Subgroup Ia and Subgroup lb. The general order of increasing degrees of hydrogeochemical evolution (due to the degrees of water-rock interaction) is: Group III$\rightarrow$Group II$\rightarrow$Group I. The Group II and III waters show smaller degrees of interaction with rocks (largely calcite and Na-plagioclase), whereas the Group I waters record the stronger interaction with plagioclase, K-feldspar, mica, chlorite and pyrite. The concentration and sulfur isotope composition of dissolved sulfate appear as a key parameter to understand the origin and evolution of geothermal waters. The sulfate was derived not only from oxidation of sedimentary pyrites in surrounding rocks (especially for the Subgroup Ib waters) but also from magmatic hydrothermal pyrites occurring in restricted fracture channels which extend down to a deep geothermal reservoir (typically for the Subgroup Ia waters). It is shown that the applicability of alkaliion geothermometer calculations for these waters is hampered by several processes (especially the mixing with Mg-rich near-surface waters) that modify the chemical composition. However, the multi-component mineral/water equilibria calculation and available fluid inclusion data indicate that geothermal waters of the Bugok area reach temperatures around $125^{\circ}C$ at deep geothermal reservoir (possibly a cooling pluton). Environmental isotope data (oxygen-18, deuterium and tritium) indicate the origin of all groups of waters from diverse meteoric waters. The Subgroup Ia waters are typically lower in O-H isotope values and tritium content, indicating their derivation from distinct meteoric waters. Combined with tritium isotope data, the Subgroup Ia waters likely represent the older (at least 45 years old) meteoric waters circuated down to the deep geothermal reservoir and record the lesser degrees of mixing with near-surface waters. We propose a model for the genesis and evolution of sulfate-rich geothermal waters.

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The investigation of the degree of the request of the education about the claim for the medical expenses in the dentistry health insurance - mainly in the Daejeon, Chungcheong area - (치과건강보험 요양급여비용 청구에 관한 교육요구도 조사 -대전·충청지역을 중심으로-)

  • Nam, Yong-Ok;Kim, Sung-Hee;Kim, Min-Ja
    • Journal of Korean society of Dental Hygiene
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    • v.11 no.3
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    • pp.325-341
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    • 2011
  • Objectives : This research has investigated the reality of the education of the claim and the degree of the education for the claimed of the dentistry recuperation organization in the Daejeon and Chuncheong are for the improvement of the problem in the medical expenses. Methods : It use as a basic data for the vitalizations of the education and performed the survey in the dentistry recuperation organization in the Daejeon and ChungCheong Nam BukDo which are registered in the evaluating organization for judging the health insurance in the present May 2010, and concluded just like the below. Results : 1. The education of the claim in the requirer in the dentistry recuperation organization, and the education of the claim was especially lacking when the dentist was studying in the university, and the dental hygienist had the similar educational experience in the school and the clinic (p<0.05) 2. Most of the requirer in the dental recuperation organization was hoping to get the education related to the claim work, but the dentist and the nurse's aid was relatively low (p<0.05) 3. For fixing the error of the claim, the participation and the extension of the judging standard of the insurance was the highest among the university subordinate dental hospital/dental hospital, but the health center was relatively low (p<0.05). 4. The dentist feels the economic burden in employing the special employee because the raising of the special judging people, compared to others, but the staffs such as the dental hygienist preferred it as one of ways to fix the error of the claim of the dental insurance (p<0.05) 5. Both dentists and the dental hygienist said proper time to teach the insurance was all needed in the school, and the clinic, but other workers relatively believed it should be held in the clinic (p<0.05). 6. The important factors to decide the participation of the lecture was in order of the contents of the lecture, the place of the lecture, the amount for the lecture, the superintendent of the lecture, whether it has gone through the educational score, and whether it has passed the conserving educational score was relatively less important in the university subordinate dentist/dentist, but the medical center was very effective as 4.50 (p<0.05) 7. Health Insurance Review and assessment service was very high as the managing department for supplying the lecture and the information, 70.5%, and the next was the Korean Dental Association/ Korean dental hygiene association, but dentists were preferring the association to manage in than the Health Insurance Review and assessment service to manage (p<0.05) 8. In preferring lecture for the inquiring the insurance, periodontal surgery was the highest as 4.51, the diagnosis standard for injection was high in the university subordinate hospital/dentists, and the more the year of the insurance inquiry, the less the doctor who was hoping for the lecture about the basic treatment. Conclusions : Taken together, it is decided that the inquiry education about the medical expense in the dentist, so the consistent and systematic education should be held to the related people, and from this, it is thought to reduce the problem of the inquiry of the medical expenses by fostering the knowledge and supplying the information which are related to the inquiry of the dentists.

The analysis of design education in "Arts & Life" (현행 고등학교 교과서 "미술과 생활" 의 디자인 교육 내용 분석)

  • 이지수;정은숙
    • Archives of design research
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    • v.17 no.3
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    • pp.221-230
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    • 2004
  • Design textbooks for general education bring our attention to the education of design as a part of whole education. In this vein, this thesis tried to analyze and discuss on the current status of design education contents included in the 7th educational curriculum of the Art & Life. This study had a historical review of the contents of arts education as well as a review of theoretical contents in art education. Also this thesis analyzed five types of Art & Life text books currently used at high schools with weight given to the design and to the status of pictorial coverage in the text books. Finally, the thesis presented problems of design education through a comparative analysis of high school arts education and design education. Through the analysis, inequality of design contents in education was reported. It was clearly attributable to the backgrounds of text book writers. For example, authors with graphic design backgrounds tended to lack product and environment design concepts, while hand craft section of text books all showed a biased contents towards traditional Korean arts. In the analysis of pictorial coverage, similar to the composition of academic contents, coverage was concentrated in the graphic design areas; inequality in quantity of pictures found with a ratio of 1 to 4. In terms of areas of arts, design contents in text books were concentrated only in arts creation chapters among the 3 major areas of arts appreciation, understanding, and creation. Design education is attained in an atmosphere of creativity and the provision of ample teaching material. It is because diverse contents will generate the development of arts. When compared to design education curriculum of U.S. and Japan, these creativity put their focus of design education in the understanding and emotional contacts, so that every application is easily attained. In terms of expression learning, creativity and diversity of material are emphasized. From Kindergarten to middle, and high school periods, apparently the care contents of deign is emphasized. A textbook in the 7th education curriculum is one of the sources for education. In designing text books, learning process should be emphasized following subjects and natures of arts so that creativity can be achieved. Therefore, a systematic approach for design research and educational development for material would be needed in textbook design.

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