• Title/Summary/Keyword: Nature Material

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A Study on the Environmentally-Friendly Characteristic of Traditional Houses in Jeju (제주지역 전통주거건축의 자연친화적 특성에 관한 연구)

  • Lee, Chang-Hee;Park, Chung-Keun
    • Journal of the Korean Institute of Rural Architecture
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    • v.16 no.2
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    • pp.35-44
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    • 2014
  • Modern society is filled with the pursuit of material wealth and great convenience due to high technology that has been introduced to all facets of society. There is no exception to this in the field of construction. Modern construction, however, has caused environmental destruction and pollution, disturbing the coexistence of humans and nature. Therefore, this thesis aims to explore how humans and nature can maintain a mutually beneficial relationship by looking into the construction of Jeju's traditional dwelling house. This thesis examines the geographical features of Jeju and looks into how Jeju people have adapted themselves to nature. It is assumed that geographical features have created Jeju's unique environment and style of architecture and differentiated Jeju's traditional houses from those of other regions. Also, it is considered that geographical features had a large impact on traditional construction such as the floor plan and the layout of buildings. Accordingly, this thesis explores the way traditional houses protected house dwellers from the natural environment and examines the wisdom of our ancestors who took advantage of the natural environment. In addition, this thesis aims to contribute to creating Jeju's unique construction culture and environment by studying materials, structures, and forms that were applied to the traditional houses of Jeju.

Seasonal Changes in Structure and Landscape of Urban Stream Corridor - In the Case of Gongji Stream in Chuncheon- (도시하천 하도구조와 경관의 계절변화 - 춘천시 공지천을 중심으로 -)

  • Jo Hyun-Kil;Han Gab-Soo
    • Journal of Environmental Science International
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    • v.14 no.8
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    • pp.739-748
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    • 2005
  • The purpose of this study is to analyze seasonal changes in structure and landscape of Gongji stream corridor in Chuncheon, and to suggest some guidelines to contribute to creating a desirable close-to- nature stream. The study seasonally surveyed floodplain and revetment conditions, channel micro-topography, streamflow level and velocity, and vegetational cover. Flooding, water level, and vegetation were major factors of affecting seasonal changes in streambed structure and stream landscape. Small sand bars and islands were considerably disturbed by flooding and water level change. However, large islands and sand bars in the upper and middle section of the study stream remained or reappeared even after flooding. Flooding also tended to repeat channel sedimentation at the same spot. Controlling water volume of the Euiam Lake, which is adjacent to the study stream, caused higher water level downstream in the dry seasons. The majority of vegetation in sand bars and islands was washed away by the floods. Vehicle passing, crop cultivation, and ball game were other elements which disturbed vegetation in the floodplain. Creating a close-to-nature stream should reflect micro-topographical changes of channel by flooding, prevent improper vehicle entry and human use, and remove concrete material in the revetment and floodplain.

An Experimental Study on the Cement-Polymer Coatings Waterproofing Method Composed with Waste Tire Chip and Waste Glass powder (폐타이어와 폐유리 미분말을 소재로 한 무기질 탄성도막 방수공법에 관한 실험적 연구)

  • 김영삼;양승도;이성일;김윤욱;오상근
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2002.11a
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    • pp.17-22
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    • 2002
  • This Waterproofing Material which mainly consisted of 2 components of waste tire chip powder and waste glass powder. This Study is abut development of waterproofing Material, There is not tried in domestic. The most Motive of this Study wishes to recycle resources and get the economic performance for waterproofing Material The result of this Study is as followings. (1) Dense waterproofing floor is formed between waste tire chip by Coupling Agent(the most effective method to encourage adhesive strength and raise cohesion of material by combination.) (2) Expected to bring effect to shorten construction period at spot application potentially space-time in moisture aspect. Also, shortening effect of construction period and spot work are considered to be gone efficiently selecting pre-mix construction method. (3) This development Waterproofing material has elasticity that nature side compatibility of cement ingredient and plastic Emulsion have when utilize and constructs waite resources (being waste tire chip and waste glass powdered).

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Solid Electrolytes Characteristics Based on Cu-Ge-Se for Analysis of Programmable Metallization Cell

  • Nam, Ki-Hyun;Chung, Hong-Bay
    • Transactions on Electrical and Electronic Materials
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    • v.9 no.6
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    • pp.227-230
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    • 2008
  • Programmable Metallization Cell (PMC) Random Access Memory is based on the electrochemical growth and removal of electrical nanoscale pathways in thin films of solid electrolytes. In this study, we investigated the nature of thin films formed by the photo doping of copper ions into chalcogenide materials for use in programmable metallization cell devices. These devices rely on metal ions transport in the film so produced to create electrically programmable resistance states. The results imply that a Cu-rich phase separates owing to the reaction of Cu with free atoms from chalcogenide materials.

Growth and properties of LCMO/YBCO heterostructure

  • Kumar, Manish;Lee, Hyun Hwi
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.151.1-151.1
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    • 2016
  • Complex oxide heterointerfaces have been extensively explored in the past due to the novel phenomenon emerging at such interfaces that differ from their individual bulk counterparts. The integration of a ferromagnetic (FM) material with the superconducting (SC) material leading to proximity effect is one of the commonly studied phenomenon in these heterostructures. In continuation, we have stabilized the FM layer La0.7Ca0.3MnO3 (LCMO) on SC material YBa2Cu3O7-${\delta}$ (YBCO) using pulsed laser deposition technique and explored the structural, magnetic, electrical and magneto-transport properties of this heterostructure. ${\Phi}$-scan measurements confirm the epitaxial nature of LCMO/YBCO heterostructure grown on single crystalline SrTiO3 substrate. The FM transition of LCMO and SC transition of YBCO are observed in the magnetization measurements of the bilayer structure. Through electrical measurements, we understood that the proximity effect leads to lowering of the SC transition of YBCO. The role of interface in the bilayer structure is also realized through electrical transport measurements.

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Prediction of Effective Material Properties for Triaxially Braided Textile Composite

  • Geleta, Tsinuel N.;Woo, Kyeongsik;Lee, Bongho
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.2
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    • pp.222-235
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    • 2017
  • In this study, finite element modeling was used to predict the material properties of tri-axially braided textile composite. The model was made based on an experimental test specimen which was also used to compare the final results. The full interlacing of tows was geometrically modelled, from which repeating parts that make up the whole braid called unit cells were identified based on the geometric and mechanical property periodicity. In order to simulate the repeating nature of the unit cell, periodic boundary conditions were applied. For validation of the method, a reference model was analyzed for which a very good agreement was obtained. Material property calculation was done by simulating uniaxial and pure shear tests on the unit cell. The comparison of these results with that of experimental test results showed an excellent agreement. Finally, parametric study on the effect of number of plies, stacking type (symmetric/anti-symmetric) and stacking phase shift was conducted.

Nonlocal finite element modeling of the tribological behavior of nano-structured materials

  • Mahmoud, F.F.;Meletis, E.I.
    • Interaction and multiscale mechanics
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    • v.3 no.3
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    • pp.267-276
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    • 2010
  • A nonlocal finite element model is developed for solving elasto-static frictional contact problems of nanostructures and nanoscale devices. A two dimensional Eringen-type nonlocal elasticity model is adopted. The material is characterized by a stress-strain constitutive relation of a convolution integral form whose kernel is capable to take into account both the diffusion process of nonlocal elasticity and the scale ratio effects. The incremental convex programming procedure is exploited as a solver. Two examples of different nature are presented, the first one presents the behavior of a nanoscale contacting system and the second example discusses the nano-indentation problem.

A Study on the Characteristics of Dual-band Plastic Chip Antenna for Mobile Terminal using the Foamex Materials (Foamex 매질을 이용한 이동통신 단말기용 듀얼밴드 플라스틱 칩 안테나 특성에 관한 연구)

  • Lee, Young-Hun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.2
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    • pp.130-135
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    • 2005
  • In this papers, we made study for plastic chip antenna, the plastic is Foamex with the circle of PVC and its electric characteristics are dielectric constant 1.9, insulation intensity 112 KV/cm. The proposed antenna is same as the conventional antennas are usually constructed with ceramic chip, which are not fragile in nature and don't tend to break easily. Therefore the proposed antenna with its advantage is attractive for application in mobile antenna. In order to valid the proposed papers, it is implemented the antennas of four types and experimented. From the results, we conformed that the antennas are operated at the dual band which is cellular band and Korea-PCS band. And the gain of the antennas has about above -2 dB and the pattern is same as conventional antennas. From this papers, the realized antennas using Foamex material will be application for mobile phone antenna.

Efficient Fluorescence Quenching of tert-butyl substituted Phthalocyanines with Picric Acid

  • Gupta, Ankush;Kim, Meena;Park, Jong S.
    • Textile Coloration and Finishing
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    • v.26 no.4
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    • pp.277-282
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    • 2014
  • Two tert-butyl substituted phthalocyanines(Pcs), in metal-free and metallated forms, were synthesized and the fluorescence responses toward various nitro derivatives, including picric acid(PA), 2,4-dinitrotoluene(DNT), 1,4-dinitrobenzene(DNB), 4-nitrotoluene(NT), nitrobenzene(NB), 1,4-benzoquinone(BQ), and nitromethane(NM) were investigated. Among the various nitro derivatives, current Pc derivatives exhibited efficient and exclusive fluorescence quenching in the presence of picric acid, which was readily observed by a naked eye. Quenching efficiency was estimated by the Stern-Volmer relationship, in which quenching constant, KSV, was calculated to be in the range of $10^4M^{-1}$. It was also found out that the aggregational behaviors of these Pcs are heavily dependent on the nature of solvent systems, subsequently affecting the quenching efficiency.

Study on the Composite Blast Wall Test (복합 재료 폭파 방화벽 실험 연구)

  • Yang, Hyun-jung;Kang, Young-Jong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.1 no.4
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    • pp.6-12
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    • 2010
  • This study investigates how to apply composite material to the blast loading protection devices, mainly used for military purpose. Traditionally, earth-filled blast walls have been used for protecting important parts of military facilities and personnels. However these types of blast walls show difficulty in fabrication and portability because of their nature of heavy weight. Composite materials are known to have relatively higher specific stiffness and strength than any other metallic and earth-filled materials such as sand and gravels. Totally 4 times of TNT blast experiments were performed on the carbon/epoxy blast walls. After the end of each test, the improvement of blast wall was implemented to the structure. The test results show that the use of composite material in the blast protecting area is the one of very effective and reliable alternatives.

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