• Title/Summary/Keyword: 교대작용

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Mineralogy and Genesis of Manganese Ores from the Eosangcheon Mine, Korea (어상주광산(魚上川鑛山)의 망간광석(鑛石)에 대(對)한 광물학적(鑛物學的) 및 성인적연구(成因的硏究))

  • Kim, Soo Jin;Kim, Seong Hoon
    • Economic and Environmental Geology
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    • v.15 no.4
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    • pp.205-219
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    • 1982
  • The Eosangcheon manganese ore deposits occur as supergene weathering deposits along quartz porphyry dikes developed in the Ordovician Heungweolri dolomite and Samtaesan limestone formations. The manganese ores are composed of manganese oxide minerals and associated other minerals. Rancieite and todorokite are abundantly found, and birnessite, nsutite, pyrolusite and chalcophanite are found in minor quantities. Associated other minerals are calcite, gypsum, goethite, lepidocrosite, quartz, and sericite. Microscopic, chemical, X-ray powder diffraction, infrared absorption spectroscopic and differential thermal analyses have been made for manganese oxide minerals and associated other minerals. The relationship of birnessite and rancieite was studied by means of X-ray powder diffraction and infrared absorption spectroscopic analyses. It is assumed that these minerals are closely related to each other in crystal structure, but separate species. The manganese oxide minerals were formed mainly by replacement, precipitation from solution, and recrystallization in the supergene weathering environment. The trend of formation of manganese oxide minerals is: (Rhodochrosite)-(todorokite)-(birnessite, rancieite)-(nsutite, pyrolusite, chalcophanite).

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Regional-scale metasomatism of Al, K, and Na during stauroliteandalusite- grade contact metamorphism, in the southwestern Nova Scotia, Canada (십자석-홍주석 접촉 변성과정에 수반된 Al, K, Na의 광역적 변성교대작용 - 캐나다 노바스코시아주 서남부의 예 -)

  • Sang-Gi Hwang
    • The Journal of the Petrological Society of Korea
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    • v.6 no.1
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    • pp.52-64
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    • 1997
  • Pelitic rocks of southwestern Nova Scotia have been affected by widespread contact metamorphism due to the intrusion of the Shellburne Pluton, with aureole up to 15 km wide. Well-preserved pseudomorphic textures indicate that common staurolite and andalusite metacrysts formed at the expense only of plagioclase, muscovite and biotite. Excess components (K, Na and Ca) from such replacement reactions imply extensive metasomatism throughout the contact aureole. Modal analysis of a typical andalusite-bearing rock indicates a one-to-one volume ratio of product to reactant. However the products of the replacement reactions contain approximately three times more aluminum than the reactants, indicating that the regional metasomatism also involved aluminum.

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Geochemical Characteristics of Clinopyroxenes in the Upper Mantle Rocks under the Baegryeong Island and the Boeun (백령도와 보은 지역의 상부맨틀암석 내의 단사휘석의 지화학적 특징)

  • Kil Young Woo;Lee Seok Hoon
    • Journal of the Mineralogical Society of Korea
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    • v.18 no.1
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    • pp.61-72
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    • 2005
  • Modal and chemical compositions of clinopyroxnes in spinel peridotites from the Baegryeong Island and the Boeun, enclosed in Miocene alkali basalt, are important for understanding the pre-eruptive temperature condition and chemical processes such as mantle depletion and enrichment. All spinel peridotites show transitional texture between protogranular and porphyroclastic textures. Temperature ranges of spinel peridotites from the Baegryeong Island and the Boeun at 15 kb are 773∼1188℃ and 705∼1106℃, respectively. The spinel peridotites from the Baegryeong Island and the Boeun have undergone the 1∼10% and 1∼4% fractional melting, which were determined by using primitive mantle-normalized Y and Yb of clinopyroxenes. LREE enrichment patterns of clinopyroxene indicate that these rocks from both areas have undergone cryptic mantle metasomatism without new minerals.

Experimental Study on Characteristics of Deformation for Concrete Track on Railway Bridge Deck End induced by Bridge End Rotation (철도교량 단부 회전에 따른 콘크리트 궤도의 변형특성에 관한 실험적 연구)

  • Lim, Jongil;Song, Sunok;Choi, Jungyoul;Park, Yonggul
    • Journal of the Korean Society for Railway
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    • v.16 no.3
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    • pp.217-225
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    • 2013
  • In this study, by considering the rail fastening support distance and the distance between the bridge and the abutment, the behavior of concrete track installed on a railway bridge end deck and the bridge end rotation were analyzed. In order to analyze the track-bridge interaction, bridge and abutment specimens with concrete track structures were designed and used in laboratory testing. At a constant fastening support distance, an increase in the bridge end rotation caused an increase in the displacement of the rail. Therefore, the displacement of the rail directly affects the rail and clip stress. Further, it is inferred that the results of multiple regression analysis obtained using measured data such as angle of bridge end rotation and fastening support distance can be used to predict the track-bridge interaction forces acting on concrete track installed on railway bridge deck ends.

Magnetite and Scheelite-Bearing Skarns in Ulsan Mine, Korea (울산 광산의 철-텅그스텐 스카른화작용)

  • Choi, Seon-Gyu;Imai, Naoya
    • Economic and Environmental Geology
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    • v.26 no.1
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    • pp.41-54
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    • 1993
  • The Ulsan Fe-W deposit, which can be classified as a calcareous skarn deposit, is represented by ore pipe consisting principally of magnetite and lesser amounts of scheelite with minor sulphides, sulphosaits, arsenides, sulpharsenides, etc. At Ulsan mine, metasomatic processes of skarn growth may be divided broadly into two stages based on the paragenetic sequence of calc-silicate minerals and their chemical composition; early and late skarn stages. Early stage has started with the formation of highly calcic assemblages of wollastonite, diopsidic clinopyroxene and nearly pure grossular, which are followed by the formation of clinopyroxenes with salite to ferrosalite composition and grandite garnets with intermediate composition. Based on these calc-silicate assemblages, the temperatures of early skarn formations have been in the ranges of $550^{\circ}$ to $450^{\circ}$. The calc-silicate assemblages formed during the earlier half period of late skarn stage show the enrichment of notable iron and slight manganese, and the depletion of magnesium; clinopyroxenes are hedenbergitic, and grandite garnets are andraditic. The formation temperatures during this skarn stage are inferred to have been in the range of $430^{\circ}$ to $470^{\circ}C$ at low $X_{CO_2}$ by data from fluid inclusions of late andraditic garnets. The later half period of late skarn stage is characterized by the hydrous alteration of pre-existing minerals and the formation of hydrous silicates. The main iron-tungsten mineralization representing prominent deposition of magnetite immediately followed by minor scheelite impregnation has taken place at the middle of early skarn stage, while complex polymetallic mineralization has proceeded during and after the late skarn stage. Various metals and semimetals of Fe, Ni, Co, Cu, Zn, As, Mo, Ag, In, Sn, Sb, Te, Pb and Bi have been in various states such as native metal, sulphides, arsenides, sulphosaits, sulpharsenides and tellurides.

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Longitudinal Dynamic Behavior of KASR-Bridge Installed Creep-Couplers (Creep-Coupler가 설치된 KHSR 교량으 종방향 동적거동)

  • 곽종원
    • Journal of the Earthquake Engineering Society of Korea
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    • v.4 no.4
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    • pp.111-116
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    • 2000
  • 경간사이에 creep-coupler가 설치된 경부 고속철도 교량에 TGV-K 열차의 제동에 의한 교량의 종방향 동적거동을 해석하였다. 교량은 40m 길이의 2경간 연속교이며, 종방향 충격 하중을 인접 경간 혹은 교대로 전달하기 위한 목적으로 인접하고 있는 두 교량 사이의 creep-coupler가 설치되었다. 철도교의 경우에는 레일에 대한 종방향 축력검토가 매우 중요하므로, 이를 지지하고 있는 교량의 하부구조(교각과 기초)의영 향을 고려한 교량의 동적거동해석이 요구된다. 본 연구에서는 TGV-K의 실제 제동하중에 의한 KHSR(Korea high speed railway)에 건설중인 실제교량의 동해석을 하부구조와 동특성치를 고려하여 수행하였다. TGV-K는 객차사이에 대차가 위치하므로 전체 열차의 모델링이 한꺼번에 이루어 져야한다. 동핵석을 위해서 열차의 3차원 수치모델링이 이루어졌다. TGV-K의 제동은 동력차의 전기적인 제동에 의한 회생제동력(regenerative braking force)과 객착의 기계적인 판제동(disk braking)으로 이루어진다. 이러한 제동작용의 고려에 실제 TGV-K의 제동함수가 사용되었다.

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홍제사 화강암질편마암체의 성인과 공존하는 흑운모, 백운모 및 녹니석 사이의 화학적 평형

  • 이상헌
    • The Journal of the Petrological Society of Korea
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    • v.3 no.1
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    • pp.49-75
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    • 1994
  • The Hognjesa granitic rocks can be subdivided into biotite granitic gneiss and microcline- perthite granitic gneiss according to their mineralogy and textures, which change gradationally each other. They consist mainly of biotite, muscovite, chlorite, microcline, plagioclase, perthite and quartz accompanied with sillimanite, garnet, and tourmaline in places. The replacement and/or alteration phenomena and relationships of coexisting minerals suggest that the granitic gneisses might be formed by regional metamorphism of upper amphibolite facies and granitization by partial melting accompanied to the regional metamorphism, and again at later effected by regional metamorphism of epidote-amphibolite or greenschist facies. The biotite, muscovite and chlorite formed during these metamorphism, show nearly similar chemical compositions, respectively, regardless to the rock phases and stages of formation. They show relatively stable chemical equilibrium between coexisting pairs. The granitization which formed granitic gneisses may be seemed to occur regionally by partial melting accompanied to the first regional metamorphism.

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Effect on Respiratory Function of the General Adult by Gait Training Based on the Way in a Speed Pattern (속도 방식에 따른 보행훈련이 일반 성인의 호흡기능에 미치는 영향)

  • Jeong, Hyung-Yoon;Cho, Woon-Soo;Choi, Ah-young;Kim, Yong-Seong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.10
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    • pp.515-522
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    • 2018
  • The purpose of this study was to determine the effect of gait training based on the way in a speed pattern on the respiratory function of general adults. A total of 37 people were divided into three groups to conduct fast, standard, and interval gait training. For gait training, a treadmill was used. Three groups were trained for 60 minutes, three times per week, for a period of 6 weeks. Inspiration pressure, maximum inspiration volume, and the size of diaphragm movement were measured. Repeated Measures ANOVA was used to compare times, groups, and interactions. For inspiratory pressure, maximum inspiration volume, and size changes in diaphragm movement, there were significant differences depending on the time and interaction between times and groups. For size changes in diaphragm's movement, there was a significant difference between interval gait training group and standard gait training group. Therefore, interval gait training had effects on size changes in diaphragm movement.

Simplified Analysis Formula for the Launching Superstructure of ILM Bridge (압출가설시 ILM교량 상부구조의 단순 해석식)

  • Moon, Seung-Il;Jang, Jae-Youp;Lee, Hwan-Woo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2011.04a
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    • pp.450-453
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    • 2011
  • 압출공법(incremental launching method)은 교대 배후에 거더 제작장소를 설치하고, 콘크리트를 이어쳐서 교량거더를 제작하고, 이것을 잭(jack)으로 밀어내는 가설방법이다. 이 공법에 의해 시공되는 교량의 상부단면은 시공 중에 지간의 중앙부와 지점부에 일시적이나마 모두 위치하게 된다. 따라서 단면들은 자중에 의해 발생되는 최대 정모멘트와 최대 부모멘트, 그리고 최대 전단력을 모두 경험하게 되는 구조적 특성을 가지고 있다. 한편 거더의 캔틸레버 작용을 감소시키기 위하여 거더의 선단에 압출추진코(launching nose)를 부착시킨다. 상부단면에 발생하는 이 일시적인 응력의 크기는 압출추진코의 단면특성에 따라 달라진다. 본 논문에서는 압출추진코와 상부단면의 상호작용에 관한 해석식의 정확성을 유지하고, 활용도를 높이기 위해서 압출추진코를 유사등단면(강성;등단면, 중량;변단면)으로 가정하여 단순화된 해석식을 제안하였고, 압출추진코의 단면이 등단면으로 가정한 기존 해석식의 정확성을 향상시키기 위해서 다이아프램의 중량을 집중하중으로 치환시켜 변형된 등단면 해석식을 제안하였다. 그리고 제안된 2개의 해석식의 정확성과 활용성을 판단하기 위해 실제 ILM교량 설계자료들을 통해 전산구조해석 프로그램과, 기존 해석식들과 비교 분석 하였다.

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Influence of Rail Supporting Spacing of Railway Bridge Deck Ends on Bridge-Track Interaction Forces (교량-궤도 작용력에 대한 교량 단부에서의 레일지지점간격의 영향)

  • Choi, Jun-Hyeok
    • Journal of the Korean Society for Railway
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    • v.17 no.4
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    • pp.245-250
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    • 2014
  • This paper, as a study for the serviceability design of railway bridges with concrete track, presents the effects of design parameters of tracks and bridges on the forces acting on the rail supports of the track. To calculate the forces acting on the track, an unequal spacing discrete supported model with different spacing of rail supports was induced. Design parameters are the rail support spacing of expansion joints above abutments or piers of bridges, the distance from the support of a girder to the last rail support on the end of the girder, and the number of additional rail supports. The causes of the displacement of track are axial force, unit vertical displacement, and unit rotation. From the analysis, the maximum compressive force and the maximum uplifting force acting on the rail supports were determined and the effects of the rail support spacing on the forces acting on the track were presented.