• Title/Summary/Keyword: Major Element

Search Result 1,575, Processing Time 0.022 seconds

Geochemistry of the Daebo Granitic Batholith in the Central Ogcheon Belt, Korea : A Preliminary Report (중부 옥천대에 분포하는 대보 화강암질 저반의 화학조성 : 예비보고서)

  • Cheong, Chang-Sik;Chang, Ho-Wan
    • Economic and Environmental Geology
    • /
    • v.29 no.4
    • /
    • pp.483-493
    • /
    • 1996
  • The tectonic environment and source characteristics of the Daebo granitic batholith in the central Ogcheon Belt were investigated based upon major and trace element geochemistry. The batholith is comprised of three granite types; a biotite granite (DBBG), K-feldspar megacryst-bearing biotite granite (DBKG), and a more mafic granodiorite (DBGD). The variations of Na and K in the granites can not be explained by simple fractional crystallization from the same primary magma. The irregular behavior of these alkali elements indicates a variety of source materials or incomplete mixing of different source materials. The large ion lithophile (LIL) element enrichment and low Ta/Hf ratios of the granites are typical characteristics of normal, calc-alkaline continental arc granitoids. Based upon REE patterns of the granites, it seems to be unreasonable to regard the felsic DBBG as a late stage differentiate formed by residual melts after the fractionation of major constituent minerals of the more mafic DBGD. Inconsistent variations in ${\varepsilon}_{Nd}(t)$ and LIL element concentrations of the granites preclude a mixing model between primitive melt and LIL element-enriched upper crustal materials. The irregular geochemical variation of the granites is taken to be largely inherited from an already heterogeneous source region.

  • PDF

THREE-DIMENSIONAL FINI6E ELEMENT ANALYSIS OF THE ENDOSSEOUS IMPLANT DESIGNS (삼차원 유한요소 해석에 의한 골내 임프란트의 구조에 관한 연구)

  • Hyun, Young-Keun;Kwon, Jong-Jin
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.35 no.1
    • /
    • pp.181-210
    • /
    • 1997
  • The stress distribution generated in the surrounding bone was calculated and compared for various geometry of the dental implants by means of the finite element methods. The models were designed to represent the screw type endosseous implants(varing the size, shape, direction of the screw thread and the angle of the body) with supporting bone and the cylinder type endosseous implants(varing the lower portion-Round type, tapered type) with supporting bone. Static mean bite forces were applied 100N vertically and 25N horizontally on the center of the implant and three dimensional finite analysis was undertaken using software ANSYS 5.1 Version. The result demonstrated that different implant shape leads to significant variations in stress distribution in the bone. In the case of variation of the screw size, direction and shape the implant model with normally directional and triangular screw implied lower stress than with upper directional or lower directional and quadrangular screw but among models a different screw size, within a variation of 0.2mm there was no meaningful difference in maximum stress. In the case of variation of angle of body the straight implied lower stress than the tapered. As a result of analysis of cylinder type, the implants with larger radius of curvature of the round form and larger diameter of the tapered form implied lower stress.

  • PDF

An Analysis of the Correlation of Engineering Education Major College Students' Technological Problem Solving Tendency between Technological Problem Solving Capability (공학 교육 전공 대학생의 기술적 문제 해결 성향과 기술적 문제 해결력 간의 상관 관계 분석)

  • Jo, Han-Jin;Kim, Taehoon
    • Journal of Engineering Education Research
    • /
    • v.16 no.6
    • /
    • pp.38-44
    • /
    • 2013
  • This study has the purpose to identify the correlation of engineering education major college students' technological problem solving tendency between technological problem solving capability. To that end, the technological problem solving tendencies of 79 students enrolled in engineering education related department in college of education, 'C' University located in Daejeon metropolitan city were examined, and the correlation of technological problem solving tendency between technological problem solving capability was analyzed through measurement of technological problem solving capability. As for the correlation among problem solving confidence a sub-element of technological problem solving tendency and technological problem solving capability, positive correlation was found in result 3, result 4 and result average. As for the correlation among approach-avoidance tendency a sub-element of technological problem solving tendency and technological problem solving capability, positive correlation was found in result 5 and result average. As for the correlation among self-control recognition degree the sub-element of technological problem solving tendency and technological problem solving capability, positive correlation was found in result 1, result 3 and result average. As for the correlation among problem solving tendency and technological problem solving capability, positive correlation was found in result 3, result 4, result 5 and result average.

A Study on Residents' Subjective Evaluation of the Elderly Housing Environment in the Suburbs of Chiba City, Japan (고령자거주요소에 대한 거주자의 주관적 평가연구 - 일본치바시근교의 유료노인시설을 대상으로 -)

  • CheHuiJohn
    • Journal of the Korean housing association
    • /
    • v.7 no.2
    • /
    • pp.139-151
    • /
    • 1996
  • The Purpose of this study is to examine residents' subjective satisfaction of the elderly housing environment and to suggest some major factors which can be used as basic design guidelines for the elderly housing. as the number of the elderly is growing in Japan For this purpose. data were collected through a questionnaire survey method, Some questions on their hope for the conditions of the elderly housing were asked to 265 old People living in the suburbs of Chiba city. Japan. Based on the findings of the statistical factor analysis, the major factors which affected on the elderly housing environment of the study can be summarized as follows ;(1)Factor1 is correlated with the space design element represented by the elderly dwelling performance and overall efficiency for the dwelling exterior space design (2)Factor2 is relative to the interior environmental element with Physiological and sensitive performance for borne services system. (3)Factor3 can be explained the moving and communication performance for Physical uneasiness of outdoor activities and request of public cultural spaces. (4)Factor4 is relative to the mental rest element with safety accidents for moving activities etc. and psychological isolation for the elderly.

  • PDF

Characteristics of Patterns on Art-Walls as an Imagery Element in Contemporary Living Spaces (국내 공동주거 공간 이미지 요소로서의 아트월 패턴 연구)

  • Park, Young-Soon;Kim, Seong-Ah;Kim, Eun-Jung;Lim, Sun-Hee
    • Korean Institute of Interior Design Journal
    • /
    • v.19 no.3
    • /
    • pp.86-94
    • /
    • 2010
  • Art-Wall is the term for a surface wall representing artistic expression by using different materials or images in interior spaces. Usually this is the focal point in an interior space and sometimes it called as an image wall. In the new millenium Art-walls began to use in living spaces. While in the early stages of the development, Art-Wall was limited in a living room, in contemporary it spread into overall living spaces using various patterns and materials. Therefore, the research on Art-Walls in contemporary living spaces is essential to understand this development. The purpose of this study is to find out characteristics of patterns on Art-Walls as an imagery element in contemporary interior spaces. To analyze the characteristic, the analysis table for Art-Walls are constructed based on classifications of wallpapers and textiles. Based on this analysis table, 89 examples of Art-Walls from four major periodicals from 2008 to 2009 were examined. As a result of the analysis, in contemporary interior spaces solid-texture pattern is most frequently appeared. Then natural motifs are the next most popular using oversized or irregular layouts. The result shows that naturalistic expression is significant in interior space in 2008 to 2009. Therefore, Art-Walls that adapted diverse patterns are an essential element in contemporary interiors to represent the major concept of the space.

The evaluation of penetration protective performance using applied element method for reinforced concrete lining (AEM을 이용한 철근콘크리트 라이닝의 관입 방호성능 평가)

  • Joo, Gun-Wook
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.21 no.3
    • /
    • pp.377-396
    • /
    • 2019
  • Explosion after penetration of a warhead in an underground structure generally causes considerable displacement, breakage and extensive damage to the target. Therefore, in order to reduce the damage effect, it is required to design an underground structure protection against penetration. In this study, major factors for improvement of penetration protection performance of reinforced concrete underground structures using applied element method are divided into strength (concrete UCS) and density (concrete thickness, reinforcement layers, reinforcement diameters, reinforcement spacings). Based on these major factors, this study performed numerical analysis of simulation of dynamic response by penetrators under various conditions and analyzed the results. The results of this study are expected to be used as basis materials to improve penetration protection performance of reinforced concrete underground structures.

Finite Element Model based on Strain Tests for Predicting Bending Strength of Small Gears for Aircraft

  • Kim, Taehyung;Seok, Taehyeon;Seol, Jin-woon;Lee, Byung-ho;Kwon, Byung-gi;Choi, Jong-yoon
    • Journal of Aerospace System Engineering
    • /
    • v.14 no.6
    • /
    • pp.91-99
    • /
    • 2020
  • This study proposes a finite element (FE) model for predicting the bending strength of small gears used in electro-mechanical actuators for aircraft. First, a strain gauge was attached to the tooth root of test gear, and the strain was measured. Subsequently, the FE model was applied to calculate the strain of the test gear, and the modeled strain was compared with the experimental strain. The results confirmed that the FE strain was very close to the experimental strain and the FE model was valid. This FE model was extended to the bending strength analysis of several small gear tooth models. The bending strengths of all the tooth models were almost identical to the ISO theoretical bending strength. Finally, the FE model was validated and the reliability of the modeled bending strength was evaluated through the strain measurement experiment.

Analysis of composite frame structures with mixed elements - state of the art

  • Ayoub, Ashraf
    • Structural Engineering and Mechanics
    • /
    • v.41 no.2
    • /
    • pp.157-181
    • /
    • 2012
  • The paper presents a review of the application of the newly proposed mixed finite element model for seismic simulation of different types of composite frame structures. To evaluate the performance of the element, a comparison with displacement-based and force-based models is conducted. The study revealed that the mixed model is superior to the others in terms of both speed of convergence and numerical stability, and is therefore considered the most practical approach for modeling of composite structures. In this model, the element is derived using independent force and displacement shape functions. The nonlinear response of the frame element is based on the section discretization into fibers with uniaxial material models. The interfacial behavior is modeled using an inelastic interface element. Numerical examples to clarify the advantages of the model are presented for the following structural applications: anchored reinforcing bar problems, composite steel-concrete girders with deformable shear connectors, beam on elastic foundation elements, R/C girders strengthened with FRP sheets, R/C beam-columns with bond-slip, and prestressed concrete girders. These studies confirmed that the model represents a major advancement over existing elements in simulating the inelastic behavior of composite structures.

Structural Variation of Alu Element and Human Disease

  • Kim, Songmi;Cho, Chun-Sung;Han, Kyudong;Lee, Jungnam
    • Genomics & Informatics
    • /
    • v.14 no.3
    • /
    • pp.70-77
    • /
    • 2016
  • Transposable elements are one of major sources to cause genomic instability through various mechanisms including de novo insertion, insertion-mediated genomic deletion, and recombination-associated genomic deletion. Among them is Alu element which is the most abundant element, composing ~10% of the human genome. The element emerged in the primate genome 65 million years ago and has since propagated successfully in the human and non-human primate genomes. Alu element is a non-autonomous retrotransposon and therefore retrotransposed using L1-enzyme machinery. The 'master gene' model has been generally accepted to explain Alu element amplification in primate genomes. According to the model, different subfamilies of Alu elements are created by mutations on the master gene and most Alu elements are amplified from the hyperactive master genes. Alu element is frequently involved in genomic rearrangements in the human genome due to its abundance and sequence identity between them. The genomic rearrangements caused by Alu elements could lead to genetic disorders such as hereditary disease, blood disorder, and neurological disorder. In fact, Alu elements are associated with approximately 0.1% of human genetic disorders. The first part of this review discusses mechanisms of Alu amplification and diversity among different Alu subfamilies. The second part discusses the particular role of Alu elements in generating genomic rearrangements as well as human genetic disorders.

Finite Element Simulation of Sheet Metal Shearing by the Element Kill Method (요소제거기법에 의한 판재 전단가공의 유한요소 시뮬레이션)

  • Ko, Dae-Cheol;Kim, Chul;Kim, Byung-Min;Choi, Jae-Chan
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.13 no.11
    • /
    • pp.114-123
    • /
    • 1996
  • The major objective of the present paper is to estabilish analytical technique in order to closely understand and analyze the actual shearing process. First of all, isothermal and non-isothermal FE-simulation of the shearing process are carried out using finite element software DEFORM. Based on preliminary simulation using DEFORM, the finite element program to analyze two dimensional shearing process is developed. The ductile fracture criterion and the element kill method are also used to estimate if and where a fracture will occur and to investigate the features of the sheared surface in shearing process. It can be seen that the developed program combined with the ductile fracture criterion and element kill method has enabled the achievement of FE-simulation from initial stage to final stage of shearing process. The effects of punch-die clearance on shearing process are also investigated. In order to verify the effectiveness of the proposed technique the simulation results are compared with the known expermental data. It is found that the results of the present work are in close agreement with the published experimental results.

  • PDF