• Title/Summary/Keyword: Ca-형

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A Study on the Highest Exposure Temperatures of Exposed Reinforced Concrete Structures at Fire (화재에 노출된 철근콘크리트 구조물의 최고노출온도 추정을 위한 연구)

  • Kim, Seong Soo;Lee, Jeong Bae;Kim, Il Kon;Song, Jong Jin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.2
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    • pp.94-100
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    • 2013
  • In this paper, Machinery analysis was conducted, in order to predict highest exposure temperatures and the analyze fire damage in the case of fire on reinforced concrete structure. After analyzing differential thermal of reference materials in accordance with temperature of concrete reference core specimen, it turned out that powerful endothermic peak came resulting from evaporation of capillary water and get water untill $200^{\circ}C$, another endothermic peak came resulting from decomposition of calcium hydroxide at $520^{\circ}C$, and then mass of reference materials remarkably decreased due to endothermic reaction. Another powerful endothermic reaction came after decomposition of calcite at $720^{\circ}C$. After analyzing X-ray diffraction of reference materials in accordance with temperature of concrete reference core specimen, it turned out that calcium hydroxide existed until the temperature of $400^{\circ}C$, but CH almost disappeared and CaO appeared from $600^{\circ}C$. The production increased in proportion to the temperature. This is because that calcium hydroxide and calcite are decomposed and CaO is produced when the temperature of concrete increases with fire. It is estimated that calcium hydroxide and calcite are utterly decomposed and peak disappears, and peak of CaO is remarkably formed instead, at the temperature of $700-800^{\circ}C$.

LINE PROFILES DEPENDENT ON THE OPACITY PARAMETER IN AZ CAS (AZ Cas의 불투명도 계수에 따른 선윤곽)

  • 김경미;최규홍
    • Journal of Astronomy and Space Sciences
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    • v.10 no.2
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    • pp.146-151
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    • 1993
  • AZ Cas는 B형의 주계열 별과 확장 대기를 가진 만기형으로 이루어진 쌍성계이다. 근성점 근처에서 Roche lobe를 채운 초거성으로부터 일어나는 질량 흐름이 미치는 효과를 구하기 위해 궤도위상 0.05와 0.09에서 불투명도 계수에 따른 AZ Cas의 선윤곽을 계산하였다. 원천 함수는 Hempe(1982)의 방법을 따라 Sobolev 근사방법을 이용하였으며 불투명도 계수가 클수록 넓은 흡수 부분을 가진 강한 선윤곽을 보였다. 궤도 위상 0.05의 부분식이세 나타난 bump는 흡수선위에 포피의 산란에 의해 생긴 방출선이 중첩되어 나타난 재방출 효과인 것으로 설명된다.

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The "Orthorhombic" Metastable Phase in the System of $NaAlSi_3O_8-CaAl_2Si_2O_8$ ($NaAlSi_3O_8-CaAl_2Si_2O_8$계의 "Immm-강조형" 부안정상)

  • 정수진;임응극;김기수;김영진
    • Journal of the Korean Ceramic Society
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    • v.19 no.1
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    • pp.13-18
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    • 1982
  • The crystallization of metastable "orthorhombic" phase from the glass in the system of Na $AlSi_3O_8-CaAl_2Si_2O_8$ is studied. These crystals are crystallized in the range of composition from $Ab_80An_20$ to An100. The symmetry of these crystals show orthorhombic as a possible space group P22121. Two probable twin models are proposed. proposed.

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Geochemical Characteristics of A-type granite in Dongcheondong, Gyeongju (경주 동천동 일대에 분포하는 A-형 화강암의 지화학적 특성)

  • Myeong, Bora;Ju, Jiwon;Kim, Junghoon;Jang, Yundeuk
    • The Journal of the Petrological Society of Korea
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    • v.26 no.3
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    • pp.271-280
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    • 2017
  • The Dongcheondong granite is alkali feldspar granite in Dongcheondong, Gyeongju. The granite is coarse grained and consists of alkali feldspar, quartz, amphibole, and biotite. Alkali feldspar is perthitic orthoclase and quartz often shows undulatory extinction. Plagioclase often shows albite twins, and biotite and amphibole emplace as interstitial minerals. The Dongcheondong granite is plotted in A-type area having high ($Na_2O+K_2O)/Al_2O_3$ and low (MgO+CaO)/FeOT ratio. The Dongcheondong A-type granite has higher $SiO_2$, $Na_2O$, $K_2O$, Zr, Y, and REE contents (except for Eu) and lower $TiO_2$, $Al_2O_3$, CaO, MgO, Sr, Ba, and Eu contents than I-type granites in Gyeongsang Basin. These results show that the geochemical characteristics of the Dongcheondong A-type granite are distinguished from I-type granite in Gyeongsang Basin. A-type granite in the Dongcheondong is thought to has been generated by partial melting of I-type tonalite or granodiorite.

Hydration of Active-Belite Cement with Gypsum and Slag (석고와 슬래그를 첨가한 Active-Belite Cement의 수화특성)

  • 이성호;박동철;김남호;최상흘
    • Journal of the Korean Ceramic Society
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    • v.35 no.4
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    • pp.330-330
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    • 1998
  • Active belite cement clinkers were synthsized by using natural raw materials with borax and calcium phosphate ({{{{ {Ca }_{3 }( {PO}_{4}) }}2) In both case {{{{alpha ^、 {C }_{2 }S }} were formed but borax was more efficient. The cement syn-thesized with the addition of borax was hydrated with the addition of anhydrite(5 wt%) and slag(30wt%, 40wt% 50wt%) The addition of 50wt% slag with anhydrite was good for strength development in 7days and the compressive strength was developed to twice than no addition of slag at 28 days strength.

Genetic Studies of Redcell Types for Individual Identification and Parentage Verification in Horse Breeds. (개체식별 및 친자판정을 위한 말의 적혈구항원형에 관한 연구)

  • 조길재;조병욱
    • Journal of Life Science
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    • v.14 no.4
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    • pp.696-701
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    • 2004
  • The present study was carried out to investigate the redcell types of horse breeds. A total of 210 horses (73 Korean native horses, 118 crossbreed horses, and 19 Mongolian horses) were tested a redcell types by serological procedure, and their phenotypes and gene frequencies were estimated. The blood groups phenotypes observed with highest frequency were Aa (27.4%, 63.6%, 63.2%), Ca (97.3%, 94.9%, 89.5%), K- (97.3%, 99.2%, 84.2%), Pa (39.7%, 44.9%, 42.1%), and Ua (71.2%, 70.3%, 63.2%) in the Korean native horse, crossbreed horse, and Mongolian horse, respectively. In the D system and Q system, phenotypes observed with highest frequency were Dbcm/dghm (12.3%), Dbcm/cgm (14.4%), Dcgm/dghm (15.8%), and Qc (56.2%), Qabc (36.4%), Qc (31.6%) in the Korean native horse, crossbreed horse, and Mongolian horse, respectively Alleles observed with highest frequency were A- (0.287), Ca(0.827), Ddghm (0.226), K- (0.985), Pa (0.358), Qc (0.494), U-(0.529) in the Korean native horse, Aa (0.529), Ca (0.776), Dbcm (0.306), K- (0.995), P- (0.531), Q- (0.504), U- (0.548) in crossbreed horse, and Aa (0.421), Ca (0.895), Ddghm (0.421), K- (0.842), Pa (0.447), Qc (0.448), Ua (0.632) in Mongolian horse. Dcfgk and D- alleles were not detected in these horses. These results present basic information for estimating the genetic relationships between the Korean native horse, and developing a system for parentage verification and individual identification in these horses.