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Reduction of Hydration Heat of Mass Concrete Using Coal Gasification Slag as Mixed Fine Aggregates (석탄 가스화 용융 슬래그를 혼합잔골재로 활용한 매스 콘크리트 수화열 저감)

  • Han, Min-Cheol;Kim, Jong;Choi, Il-Kyeung;Han, Jun-Hui
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.6
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    • pp.551-562
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    • 2021
  • In this study, to suggest an efficient method of using coal gasification slag(CGS), a byproduct from integrated gasification combined cycle(IGCC), as a combined fine aggregate for concrete mixture, the diverse performances of concrete mixtures with combined fine aggregates of CGS, river sand, and crushed sand were evaluated. Additionally, using CGS, the reduction of the hydration heat and the strength developing performance were analyzed to provide a method for reducing the heat of hydration of mass concrete by using combined fine aggregate with CGS and replacing fly ash with cement. The results of the study can be summarized as follows: as a method of recycling CGS from IGCC as concrete fine aggregate, a combination of CGS with crushed sand offers advantages for the concrete mixture. Additionally, when the CGS combined aggregate is used with low-heat-mix designed concrete with fly ash, it has the synergistic effect of reducing the hydration heat of mass concrete compared to the low-heat-designed concrete mixture currently in wide use.

Estimation of Setting Time of Super Retarding Mortar Using Settimeter (세티메타를 이용한 초지연 모르타르의 응결시간 추정)

  • Jeong, Yeong-Jin;Hyun, Seung-Yong;Han, Jun-Hui;Kim, Jong;Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.6
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    • pp.673-682
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    • 2023
  • This study investigates the delay in setting characteristics of mortar influenced by variations in super retarding agent(SRA) content, curing temperature, and strength levels. Utilizing a settimeter, the research introduces an objective approach to accurately determine the setting time of concrete with SRA under diverse environmental and material mixing conditions at construction sites. The findings indicate that the settimeter, in conjunction with a nonlinear regression model, can effectively estimate the setting time of super retarding mortar. Optimal management of the initial setting is recommended at approximately 45ST and the final setting around 80ST. This methodology enables more effective quality control in the setting times of super retarding concrete.

Utilization of Immersion-Drying Method for Measuring Damage Depth of Fire-Damaged High-Strength Concrete (화재로 손상된 고강도 콘크리트의 손상 깊이 측정을 위한 수중침지 건조방법의 활용)

  • Kim, Jong;Lim Gun-Su;Beak, Seung-Bok;Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.3
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    • pp.297-308
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    • 2024
  • This study presents a novel approach for evaluating fire-induced damage depth in concrete. The methodology leverages the principle that exposure to high temperatures causes internal expansion within concrete, leading to increased voids and microcracks in the damaged zones. This heightened porosity results in greater absorption rates compared to undamaged areas. By immersing fire-damaged concrete samples in water and subsequently monitoring the drying process, the depth of damage can be assessed. Differences in drying rates and color variations between damaged and undamaged areas serve as visual indicators for determining the extent of the damage. Experimental results from this water immersion method revealed damage depths of 38.7mm and 37.5mm for two different concrete mixtures. These measurements notably surpass the damage depths estimated using traditional phenolphthalein-based methods. This discrepancy suggests that utilizing the absorption rate principle, which is directly linked to the physical changes caused by thermal expansion, offers a more accurate and sensitive assessment of fire damage depth compared to methods relying solely on the presence of Portlandite for colorimetric indication.

고려왕조대 고려와 교류하였던 제국과 고려의 복식제도에 관한 연구

  • 임명미
    • Journal of the Korean Society of Costume
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    • v.20
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    • pp.31-47
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    • 1993
  • 1. The relationship between Korea and Buk-Song had maintained for 164 years(964 1126 A.D). The period of relationship was from KwangJong Year 13(4years after establishing Buk-Song), Song Tae-Cho 1 year, to HeumJong Cheong Dang 1st year(InJong 4years in Koran). Author divides into three periodic terms, and remarkable diplomatic facts are as follows. 1) KwangJong year 13(963 A.D) SungJong year 13(994 A.D) : Normal relations, Song needed Korea's armed support. 2) MokJong year 6(1003 A.D) HyunJong year 9(1018 A.D) : Not steady relations and broke up, by MunJong year 26, Dang requested to resume the diplomatic relations. 3) MunJong year 25(1017 A.D) InJong 4(1126 A.D) : Song utilized Korea as a back supporter, but Song destructed by Keum. 2. Korea was donated knightage without offcial clothing by BukSong 10 times(KwangJong year 13 SungJong year 11). However during 164 years. Song presented some clothings Korea friendly. 3. Even though Korea cound not continue the steady diplomatic relations, Korea had been influenced the social systems including cloth-ing systems by Dang. Song dynasty. 4. The author studys historical materials which show that TongilSh-Shinra adapted social systems of Dang dynasty including clothing systems, which was succeeded to Korea for 200 years. Details are as follows ; 1) Original clothing color-systems which were Ja(purpil), Cheong(blue), Hwang(yellow), Pi, called 4-clored-system, of Tongil-Shinra, was suceeded to Korea, Above mentioned clothing systems of three countries of Korean peninsula. 2) When Korea unified the certificate of Pisam holders were superior from those of Tongil-Shinra and Hoo-Bakjae. There two classes used same seried-color 'ja, (Dan, Pi), Cheong(blue), Hwang(yellow)', or 'ja, (Dan, Pi), Cheong' and lasted to KwangJong year10 as a of-ficial clothing. 3) KwangJong year 7, according to the three colored official clothing system of Hooju, accepted Hooju's KwangJong year 11, that shifted 'Ja, (Dan, Pi), Cheong, Hwang', or, Ja, (Dan, Pi) Cheong', to 'Ja, Dan, Pi, Rok(green)'. 4) The clothing systems which are ja, (Dan, Pi), Rok which established KwangJong year 11 shifted to Song's, Ja, Ju(orange), Rok, Cheong, which had happened SungJong year 14 to MokJong 1st year. 5) 4-colored systems ('Ja, Pi, Rok, Cheong (distictable : sky blue, ocean blue)' shifted to 3 colored system which established Song ShingJong 1st year, which succeeded to Nam-Song and Keum. 5. The relationship between Korea and Yo had maintained for 207 years(918 1125 A.D). The period of relationship was from TaeJo 1st year to InJong year 3. 6. Yo, and Korea were called for king(15 times), prince(7 times). 7. Korea was donated knightage by Yo. The time when HyunJong year 13, Yo donated official clothing. From that time had used to do. The author divides into three periodic terms and discrives the shifting the formal clothing systems. Details were as follows ; 1) HyunJong year 13 MunJong year 8 : Even donating clothing systems from Yo had maintained for 35 years, Yeo, Song, Yo, three countries had not have formal cloth-ing, because they had been on the strug-gling. So that Korea had followed the same way of informal clothing. 2) MunJong year 918 : Yo donated the formal clothing to Korea for the King. Diplomatic condition was in the control, so that whole three countries used formal clothing. 3) MunJong year 19 YeaJong year 3 : Korea was donated 'Kuryumyun Kujangbokje', which became the formal clothings vs China.

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Comparison of Growth Characteristics and Productivities of Hairy Vetch (Vicia villosa) Varieties (헤어리 베치의 품종별 생육 특성과 생산성 비교)

  • Lee, Joung-Kyong;Lim, Keun-Bal;Kim, Ki-Yong;Choi, Gi-Jun;Seong, Byung-Ryul;Seo, Sung;Ji, Hee-Chung;Choi, Yeon-Sik;Shin, Jeong-Nam;Park, Hyung-Soo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.27 no.4
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    • pp.249-256
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    • 2007
  • This experiment was conducted to compare the agronomic characteristics and productivity in introduced hairy vetch cultivars and developed new Korean Hairy vetch cultivars in two areas of the experimental field of Grassland and Forage Crops Division, National Institute of Animal Science from 2005 to 2006. The experiment was arranged in randomized complete block design with three replications. A total of 11 hairy vetch cultivars used in this study including 9 introduced cultivars (Penn-02, Sander, Latigo, Welta, Ostsaat, VV4712, Minnie, Barlosa and Capello) and 2 Korean cultivars (Cold green and Cheong pa). The early flowering varieties of Minnie, Barlosa, Capello and Cold green were grown as early maturity cultivars, while the late flowering varieties of Penn-02, Sander, Latigo, Welta, Ostsaat, VV4712 and Cheong pa were grown as medium and late maturity. The winter hardiness of hairy vetch was good except for Minnie, Barlosa and Capello of early maturity cultivars. In this study, dry matter yield of VV4712 was the highest of 11 hairy vetch cultivars. And dry matter yield of medium and late maturity vetch increased in the middle region while that of early maturity increased in the south. The new Korean cultivar, Cheong pa, as a medium and late maturity hairy vetch was not bad compared to introduced cultivars and Cold green as an early maturity hairy vetch was an excellent cultivar compared to introduced cultivars in both regions. Latigo in NDF (neutral detergent fiber) and Welta in ADF (acid detergent fiber) were lower than other cultivars, while Sander in IVDMD (in vitro dry matter digestibility) and CP (crude protein) content were higher than other cultivars. The results of this experiment indicated that the productivity of hairy vetch cultivars was highest in VV4712, and Cheong pa and Cold green of new Korean cultivar were the promising cultivars of hairy vetch in Korea.

Changes in oligosaccharide content during the storage period of maesil cheong formulated with functional oligosaccharides (기능성 올리고당으로 제조한 매실청의 저장기간 중 올리고당 함량 변화)

  • Bae, Moon-Joo;Yoo, Sang-Ho
    • Korean Journal of Food Science and Technology
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    • v.51 no.2
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    • pp.169-175
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    • 2019
  • This study was carried out to produce the health functional food maesil cheong by replacing sucrose with isomaltooligosaccharide and fructooligosaccharide. The substitution levels of these oligosaccharides were between 10% and 100%. A 1:1 (w/w) mixture of maesil and sugar was adopted for preparing maesil cheong. The pH of maesil cheong remained unchanged (between 2.72 and 3.00) during 90-day storage period, regardless of oligosaccharide content. Citric and malic acids were identified in maesil cheong; citric acid accounted for 71-82% of the total organic acid content. Sucrose was completely liquefied in the sample after 30 days and was hydrolyzed steadily into fructose and glucose over the storage period. More than 75% of isomaltooligosaccharides remained in maesil cheong after 90 days when sucrose was completely replaced with isomaltooligosaccharide. However, fructooligosaccharides were mostly decomposed at the end of storage period. Thus, isomaltooligosaccharides may be suitable for acidic maesil cheong products to expect its health functional effect.

Leptin Polymorphisms Associated with Carcass Traits of Meat in Korean Cattle

  • Cheong, Hyun Sub;Yoon, Du-Hak;Kim, Lyoung Hyo;Park, Byung Lae;Chung, Eui Ryong;Lee, Han Ju;Cheong, Il-Cheong;Oh, Sung-Jong;Shin, Hyoung Doo
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.11
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    • pp.1529-1535
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    • 2006
  • Leptin has been investigated as a candidate gene for fat characteristics in beef cattle. Previously, we have reported 57 sequence variants discovered in Korean cattle (Bos Taurus coreanae). In this study, we examined the association between polymorphisms of leptin and carcass traits (cold carcass weight (CWT) and marbling score (Marb)) in Korean cattle. Among 57 polymorphisms, 11 common polymorphic sites were genotyped in our beef cattle (n = 437). Statistical analysis revealed that one single nucleotide polymorphism in coding exon (c.+411T>C (A137A)) showed a significant association with the yield trait, CWT. The C-bearing genotypes (CC or CT) of c.+411T>C (A137A) showed the higher CWT (p = 0.006). c.+150C>G (S50S) also showed a significant association with the quality trait, Marb (p = 0.01). Our findings suggest that polymorphisms in leptin might be one of the important genetic factors that influence carcass yield and quality in beef cattle, especially in CWT and Marb.

The Study for Investigation of the sufficient vertical profile with reducing loading effect for silicon deep trench etching (Vertical Profile Silicon Deep Trench Etch와 Loading effect의 최소화에 대한 연구)

  • Kim, Sang-Yong;Jeong, Woo-Yang;Yi, Keun-Man;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.118-119
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    • 2009
  • This paper presents the feature profile evolution silicon deep trench etching, which is very crucial for the commercial wafer process application. The silicon deep trenches were etched with the SF6 gas & Hbr gas based process recipe. The optimized silicon deep trench process resulted in vertical profiles (87o~90o) with loading effect of < 1%. The process recipes were developed for the silicon deep trench etching applications. This scheme provides vertically profiles without notching of top corner was observed. In this study, the production of SF6 gas based silicon deep trench etch process much more strongly than expected on the basis of Hbr gas trench process that have been investigated by scanning electron microscope (SEM). Based on the test results, it is concluded that the silicon deep trench etching shows the sufficient profile for practical MOS FET silicon deep trench technology process.

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The Study of WET Cleaning Effect on Deep Trench Structure for Trench MOSFET Technology (Trench MOSFET Technology의 Deep Trench 구조에서 WET Cleaning 영향에 대한 연구)

  • Kim, Sang-Yong;Jeong, Woo-Yang;Yi, Keun-Man;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.88-89
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    • 2009
  • In this paper, we investigated about wet cleaning effect as deep trench formation methods for Power chip devices. Deep trench structure was classified by two methods, PSU (Poly Stick Up) and Non-PSU structure. In this paper, we could remove residue defect during wet. cleaning after deep trench etch process for non-PSU structure device as to change wet cleaning process condition. V-SEM result showed void image at the trench bottom site due to residue defect and residue component was oxide by EDS analysis. In order to find the reason of happening residue defect, we experimented about various process conditions. So, defect source was that oxide film was re-deposited at trench bottom by changed to hydrophobic property at substrate during hard mask removal process. Therefore, in order to removal residue defect, we added in-situ SCI during hard mask removal process, and defect was removed perfectly. And WLR (Wafer Level Reliability) test result was no difference between normal and optimized process condition.

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A Study on the Organization and Contents of "CheongKangEuiGam" (『청강의감』의 구성과 내용)

  • Oh, Junho
    • The Journal of Korean Medical History
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    • v.27 no.2
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    • pp.63-74
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    • 2014
  • The purpose of this study is to investigate the organization and contents of "CheongKangEuiGam" and raise interests in study on Oriental Medicine in the 20th century. Songjae, LeeJongHyeong was a disciple of Cheongkang and published this book in 1984 by organizing the medical theory of Cheongkang, KimYoungHoon who lived in the turbulent period from the late period of Joseon to a chaotic state of Korea after the independence of Korea. Even though it is relatively recently published, it is a very important clinical book as well as historical material to look at the aspects of Oriental Medicine in the 20th century. The book contains several notable medical thoughts. First, you can look at one perspective of the 20th century Oriental Western medical study which is initiated by the introduction of Western Medicine in classification schemes and description of disease symptoms. In addition, he uses medicinal herbs such as Cyperus rotundus L., Pinellia ternate(Thunb.) Breit., Poria cocos Wolf, Angelica gigas Nakai, Cnidium officinale, and Paeonia lactiflora Pall as important items, it is found that qi and blood depressed gallbladder is considered as the main pathology of the disease. In terms of names and meaning of prescriptions, he prefers to use mild medicinal herbs rather than intense medicinal herbs. It seems that he tries to help people's lives with cheap and effective medicinal herbs.