• 제목/요약/키워드: Element group

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도.토기의 과학적 분석 연구-충청 남.북도, 강원도 토기 도요지 중심으로 (The scientific analysis of potteries-Focus on the potteries excavated from kiln sites at Chungcheong Nam∙Buk-do and Gangwon-do)

  • 홍종욱;한민수;황진주;강대일
    • 보존과학연구
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    • 통권24호
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    • pp.99-130
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    • 2003
  • This research carried out composition analysis the subject of potteries from kiln site at Gangwon-do, Chungcheong Nam∙Buk-do and the followings are the results. Firstly, XRD analysis results showed that soft potteries were consisted of $\alpha$-quartz, feldspar and soil minerals while hard potteries were consisted of high temperature crystals like mullite, tridymite and cristobalite. Secondly, the firing temperatures of the soft potteries were determined using XRD analysis. It ranged from $550^{\circ}C$ to $870^{\circ}C$.While the firing temperatures of the hard potteries were divided into 3 groups; Group Ⅰ: Potteries with Mullite and Feldspar - ranged from $1000^{\circ}C$ to$1200^{\circ}C$. Group II : Potteries with Mullite and Tridymite - ranged from $875^{\circ}C$ to $1200^{\circ}C$. Group III : Potteries with Cristobalite - ranged above $1200^{\circ}C$.Thirdly, the result of correlation analysis using trace element such asSc, Rb of the potteries form Gangwon do and Chungcheong Nam.Bukdokilns allowed us to divide the area with their own characteristics into 4-groups. Using the same result, kilns sited at Chungcheong Nam.Buk-do were classified into 3-groups.

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옥천 각섬암의 Sm-Nd 동위원소연구 : 예비보고서 (Sm-Nd Isotopic Study of the Ogcheon Amphibolite, Korea: Priliminary Report)

  • 권성택;남정영
    • 자원환경지질
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    • 제24권3호
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    • pp.277-285
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    • 1991
  • We applied Sm-Nd isotopic system to so-called amphibolites occurring within the Ogcheon group to provide constraints on the age of the metasedimentary rocks and to characterize tectonic environment of basaltic magmatism. An internal mineral isochron age of $677{\pm}91Ma({\sigma})$ was obtained from a coarse-grained, intrusive, amphibolite near Mungyeong. Considering previous studies on the age of the Ogcheon group, we interpret that the isochron represents either early metamorphic or emplacement age. The depositional age of the metasedimentary rocks intruded by the amphibolite would be prior to late Proterozoic. The present study and Cambro-Ordovician fossil evidences of previous workers suggest that both Precambrian and Phanerozoic rocks are present in the Ogcheon group. Positive ${\varepsilon}$ Nd values(+2.4 to +3.5) of four whole rocks indicate mantle origin for the amphibolite. These isotopic data, along with published immobile trace element data of Cluzel et al.(1989), strongly suggest that parental rocks of the amphibolite formed in an intraplate environment rather than in island arc or midocean ridge. The age and tectonic environment of amphibolites in the Ogcheon belt suggest that the basaltic magmatism may be related to the late Proterozoic break-up of a presumed supercontinent, but not to the Triassic(?) collision between North and South China continents.

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Cu 첨가가 Mo-Cu-N 코팅의 미세구조와 기계적 특성에 미치는 영향 (Effects of Cu Addition on Microstructural and Mechanical Properties of Mo-Cu-N Coatings)

  • 김수빈;윤혜원;이한찬;문경일;홍현선
    • 한국표면공학회지
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    • 제52권4호
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    • pp.227-232
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    • 2019
  • Mo-N based coatings have been studied for enhancing mechanical characteristics of thin films. In the case of Mo-X-N coatings, the microstructure and mechanical properties can be affected by the addition of the third element. In this work, Mo-Cu-N coatings were successfully fabricated with varying the Cu content from 4.5 at% to 31 at% by the co-sputtering method. Thus, properties of the coatings were analyzed by EDS, SEM, XRD, AFM, nano indentation and scratch test techniques. From observed results, MoxN bonds were made in a nitrogen atmosphere and Cu elements were present at grain boundaries. In addition, coatings with the Cu content above 14 at% had a Cu3N peak in the XRD results. Thus, it is suggested that the formation of Cu3N phase affected the microstructure and mechanical properties of Mo-Cu-N coatings. Mechanical properties of Mo-Cu-N coatings were found to be relatively better at Cu content of about 12 at%.

인도네시아의 이슬람 급진주의: 역사적 전개과정과 이념적·실천적 특성 (Islamic Radicalism in Indonesia: Historical Development, Ideology and Praxis)

  • 김형준
    • 동남아시아연구
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    • 제19권2호
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    • pp.57-91
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    • 2009
  • The purpose of this paper is to examine historical development, ideology and praxis of Islamic radicalism in Indonesia. In the second part of this paper, radical trends under Sukarno and Suharto governments will be dealt with, focusing on three streams of Darul Islam, Dewan Dakwah Islamiyah Indonesia and Islamic secret sects. The third part investigates the surge of radical Islamic movements after the fall of Suharto regime. For this, three organizations are again selected for detailed analysis. This paper argues that, judging from active engagements of radical organizations in national and international affairs and favorable attitude of general Muslims toward them, radicalism has recently established itself as one of the major constituents of Indonesian Islam. To put it differently, the current situation signifies that under the Suharto regime, a diversification of so-called the santri has been underway. Contrary to the traditional santri group which emphasizes the fulfillment of faith in the private sphere, another group has been crystallized, which gives priority to Islamic roles in public sphere and attempts to realize these. It is difficult to pinpoint the reasons why this group has emerged. Its effect, however, can relatively easily be grasped. With the surge of this new radical stream, the rhetoric of an establishment of Islamic state and a realization of Islamic law has no longer been tabooed and has been instated as the key element in public discourse of Islam.

초등학교 과학과 검정 교과용 도서에 제시된 창의·융합 활동의 STEAM 요소 분석: 3~4학년군을 중심으로 (Analysis of STEAM Elements of Creative and Convergent Activities Presented in Elementary School Science Authorized Textbooks: Focusing on the 3rd and 4th Grade Group)

  • 김성룡;박정우;신애경
    • 대한지구과학교육학회지
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    • 제15권2호
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    • pp.224-234
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    • 2022
  • 이 연구의 목적은 2022년부터 국정 발행체제에서 검정 발행체제로 전환되는 초등학교 과학과 교과용도서의 창의·융합 활동에 나타난 STEAM 요소와 융합유형을 분석하고자 하였다. 이 연구를 위해 창의·융합 활동이 제시된 6종의 초등학교 과학 3~4학년 교과서를 선정하여 각 출판사별, 학년-학기별, 과학 분야별로 창의·융합 활동에 나타난 STEAM 요소를 분석하고 각 출판사별로 융합유형을 분석하였다. 이 연구의 결과는 다음과 같다. 첫째, 교과서의 창의·융합 활동에 나타난 STEAM 요소의 전체 빈도와 각 요소별 비율이 출판사별로 다르게 나타났다. 그러나 모든 출판사에서 과학(S) 요소를 제외한 나머지 4개의 요소 중 예술(A) 요소의 비율이 높고, 수학(M) 요소의 비율이 매우 낮은 경향은 공통적으로 나타났다. 둘째, 전체적으로 융합된 STEAM 요소의 수가 많을수록 교과서에 나타나는 비율은 낮았고, STEAM 요소의 융합유형 비율은 출판사 마다 다르게 나타났다. 셋째, 매 학년-학기별로 예술(A) 요소, 기술(T), 공학(E) 요소의 비율 편차는 크지 않았으나 수학(M) 요소의 비율 편차는 크게 나타났다. 넷째, '운동과 에너지'와 '물질' 분야에는 기술(T)과 공학(E) 요소가 많이 나타난 반면 '지구와 우주', '생명', 그리고 '통합' 분야에는 예술(A) 요소가 매우 많이 나타났다.

Peanut sprouts extract (Arachis hypogaea L.) has anti-obesity effects by controlling the protein expressions of $PPAR{\gamma}$ and adiponectin of adipose tissue in rats fed high-fat diet

  • Kang, Nam E;Ha, Ae Wha;Woo, Hye Won;Kim, Woo Kyoung
    • Nutrition Research and Practice
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    • 제8권2호
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    • pp.158-164
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    • 2014
  • BACKGROUD/OBEJECTIVES: This study aims to find out the effects of peanut sprout extracts on weight controls and protein expressions of transcription factors related to adipocyte differentiation and adipocytokine in rats under high-fat diets. MATERIALS/METHODS: Four week-old Sparague-Dawley (SD) were assigned to 4 groups; normal-fat (NF) diets (7% fat diet), high-fat (HF) diets (20% fat diet), high fat diets with low peanut sprout extract (HF + PSEL) diet (20% fat and 0.025% peanut sprout extract), and high fat diets with high peanut sprout extract (HF + PSEH) diet (20% fat and 0.05% peanut sprout extract). Body weight changes, lipid profiles in adipose tissue, and the mRNA protein expressions, such as peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$), CCAAT element binding protein ${\alpha}$ (C/EBP ${\alpha}$), leptin, and adiponectin, were determined. RESULTS: After 9 weeks of feeding, the HF + PSEH group had significantly less weight gains than the HF group (P < 0.05). However, the total dietary intakes or food efficiency ratios among groups were not significantly different. The weight of epididymal fat in HF + PSEH group, $3.61{\pm}0.5g$, or HF + PSEL group, $3.80{\pm}0.7g$, was significantly lower than the HF group, $4.39{\pm}0.4g$, (P < 0.05). Total lipids and total cholesterol in adipose tissue were significantly decreased in HF + PSEH group compared to those in the HF group, respectively (P < 0.05). PSEH supplementation caused AST and ALT levels to decrease when it compared to HF group, but it was not statistically significant. The protein expression of $PPAR{\gamma}$ in HF + PSEH group was significantly lower than the HF group (P < 0.05). Comparing with the HF group, the protein expression of adiponectin in HF + PSEH group was significantly increased (P < 0.05). The protein expressions of C/EBP ${\alpha}$ and leptin in HF + PSEH group were lower than the HF group, but it was not statistical significant. CONCLUSIONS: In conclusion, peanut sprout extract has anti-obesity effect by lowering the expressions of $PPAR{\gamma}$ which regulates the expression of adiponectin.

강-소성 유한요소법의 역추적기법을 이용한 정밀정형 쉘 노우징 부품의 성형공정 개발과 실험적 증명 (Process Development to Form Net-Shape Nosing Shells by the Backward Tracing Scheme of the Rigid-Plastic FEM and Its Experimental Confirmation)

  • 김상현;이진희;임학진
    • 대한기계학회논문집A
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    • 제20권7호
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    • pp.2118-2133
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    • 1996
  • A preform is designed by the backward tracing scheme of the rigid-plastic finite element method(FEM) for net-shape shell nosing components without machining after forming. The current process of the shell nosing requires cost-consuming machining to produce final products. Here, the backward tracing scheme of the rigid-plastic FEM, a novel method for preform design of metal forming processes, derives a sound preform for net-shape shell nosing product. The current process is simulated by the rigid-plastic finite element analysis to check the metal flow involved in the forming with a trial preform and its modified preform. The two preforms are found to be inadequate for net-shape shell nosing product. The first application of the back ward tracing scheme derives a preform producing a not-shape shell nosing product. The first application of the backward tracing scheme derives a preform producing a net-shape product numerically, but it is difficult to be formed economically as a preform. Thus an improved preform is designed by the badkward tracing scheme, which is suitable for net-shape manufacturing of the shell nosing components in view of economy of production and forming characteristics of the product. The preform in the current process and a modified preform are confirmed by a series of experiments and the results give the same deformation with the numerical ones. Finally the newly designed preform by the FEM was experimentally proved to be adequate in obtaining net-shape products.

Interaction analysis of three storeyed building frame supported on pile foundation

  • Rasal, S.A.;Chore, H.S.;Sawant, V.A.
    • Coupled systems mechanics
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    • 제7권4호
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    • pp.455-483
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    • 2018
  • The study deals with physical modeling of a typical three storeyed building frame supported by a pile group of four piles ($2{\times}2$) embedded in cohesive soil mass using three dimensional finite element analysis. For the purpose of modeling, the elements such as beams, slabs and columns, of the superstructure frame; and that of the pile foundation such as pile and pile cap are descretized using twenty noded isoparametric continuum elements. The interface between the pile and the soil is idealized using sixteen node isoparametric surface element. The soil elements are modeled using eight nodes, nine nodes and twelve node continuum elements. The present study considers the linear elastic behaviour of the elements of superstructure and substructure (i.e., foundation). The soil is assumed to behave non-linear. The parametric study is carried out for studying the effect of soil- structure interaction on response of the frame on the premise of sub-structure approach. The frame is analyzed initially without considering the effect of the foundation (non-interaction analysis) and then, the pile foundation is evaluated independently to obtain the equivalent stiffness; and these values are used in the interaction analysis. The spacing between the piles in a group is varied to evaluate its effect on the interactive behaviour of frame in the context of two embedment depth ratios. The response of the frame included the horizontal displacement at the level of each storey, shear force in beams, axial force in columns along with the bending moments in beams and columns. The effect of the soil- structure interaction is observed to be significant for the configuration of the pile groups and in the context of non-linear behaviour of soil.

Interaction analysis of a building frame supported on pile groups

  • Dode, P.A.;Chore, H.S.;Agrawal, D.K.
    • Coupled systems mechanics
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    • 제3권3호
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    • pp.305-318
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    • 2014
  • The study deals with the physical modeling of a typical building frame resting on pile foundation and embedded in cohesive soil mass using complete three-dimensional finite element analysis. Two different pile groups comprising four piles ($2{\times}2$) and nine piles ($3{\times}3$) are considered. Further, three different pile diameters along with the various pile spacings are considered. The elements of the superstructure frame and those of the pile foundation are descretized using twenty-node isoparametric continuum elements. The interface between the pile and pile and soil is idealized using sixteen-node isoparametric surface elements. The current study is an improved version of finite element modeling for the soil elements compared to the one reported in the literature (Chore and Ingle 2008). The soil elements are discretized using eight-, nine- and twelve-node continuum elements. Both the elements of superstructure and substructure (i.e., foundation) including soil are assumed to remain in the elastic state at all the time. The interaction analysis is carried out using sub-structure approach in the parametric study. The total stress analysis is carried out considering the immediate behaviour of the soil. The effect of various parameters of the pile foundation such as spacing in a group and number piles in a group, along with pile diameter, is evaluated on the response of superstructure. The response includes the displacement at the top of the frame and bending moment in columns. The soil-structure interaction effect is found to increase displacement in the range of 58 -152% and increase the absolute maximum positive and negative moments in the column in the range of 14-15% and 26-28%, respectively. The effect of the soil- structure interaction is observed to be significant for the configuration of the pile groups and the soil considered in the present study.

지반의 비선형성을 고려한 암반지진에 의한 구조물의 수평방향 탄성거동 (Elastic Horizontal Response of a Structure to Bedrock Earthquake Considering the Nonlinearity of the Soil Layer)

  • 김용석
    • 한국지진공학회논문집
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    • 제6권3호
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    • pp.53-62
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    • 2002
  • 지반조건은 구조물의 지진거동에 매우 큰 영향을 미치고 성능에 기준한 내진설계에 중요한 요소이다. 이 논문에서는 지진에 의한 지반의 비선형성을 포함한 지반의 비선형성이 구조물의 탄성지진거동에 미치는 영향을 지반 구조물 일괄해석 유한요소법과 지반의 비선형성을 구현하기 위해 Ramberg-Osgood 토질모델에 대한 근사선형 반복해석법으로 연구하였다. 연구는 말뚝기초의 유무를 고려한 주기가 변하는 선형 단자유도계에 지표에서 기록된 1940년 EI Centre지진을 적용하여 수행하였다. 연구결과에 의하면 연약지반의 비선형 특성 영향이 구조물의 탄성 지진거동에 매우 중요하곡 성능에 기준한 지반의 비선형성을 고려한 구조물의 내진설계가 필요하다는 것을 잘 보여주고 있다.