• 제목/요약/키워드: Material basis

검색결과 1,695건 처리시간 0.031초

Utilization of Some Industrial Wastes for Producing of Polymeric Composite Materials

  • Hojieva, Alohida;Rustamov, Abduvali;Ahmedov, Akmal
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2003년도 International Symposium on Clean Environment
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    • pp.95-98
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    • 2003
  • Polymeric composite materials on the basis of some industrial wastes are obtained. Some physical parameters of experimental samples are determined. The analysis of exploitative properties of these polymer composite materials allows recommending them as a heat-insulating material in constructions.

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Spherical Particles Formation in Lubricated Sliding Contact -Micro-explosion due to the Thermally-activated Wear Process-

  • Kwon, O.K.
    • Tribology and Lubricants
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    • 제11권5호
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    • pp.1-9
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    • 1995
  • The mechanism of various spherical particles formation from wide range of tribo-systerns is suggested and deduced by the action of micro-explosion on the basis of the thermally-activated wear theory, in which the flash temperature at contact could be reached clearly upto the material molten temperature due to the secondary activation energy from the exothermic reactions involving lubricant thermo-decomposition, metals oxidation, hydrogen reactions and other possible complex thermo-reactions at the contacts. Various shapes of spherical particles generated from the tribosystem can be explained by the toroidal action of micro-explosion accompanied with the complex thermo-chemical reactions at the contact surfaces or sub-surfaces.

Theoretical Investigation of Edge-modified Zigzag Graphene Nanoribbons by Scandium Metal with Pyridine-like Defects: A Potential Hydrogen Storage Material

  • Mananghaya, Michael
    • Bulletin of the Korean Chemical Society
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    • 제35권1호
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    • pp.253-256
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    • 2014
  • Functionalization of zigzag graphene nanoribbon (ZGNR) segment containing 120 C atoms with pyridine (3NV-ZGNR) defects was investigated on the basis of density-functional theory (DFT) calculations, results show that edge-modified ZGNRs by Sc can adsorb multiple hydrogen molecules in a quasi-molecular fashion, thereby can be a potential candidate for hydrogen storage. The stability of Sc functionalization is dictated by a strong binding energy, suggesting a reduction of clustering of metal atoms over the metal-decorated ZGNR.

철근콘크리트 장주의 극한저항력 (Ultimate Resisting Capacity of Slender RC Columns)

  • 곽효경;김진국
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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    • pp.275-282
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    • 2001
  • In this paper, nonlinear analyses of RC (Reinforced Concrete) columns are conducted, and an improved criterion to estimate the design load carrying capacity of slender RC columns is proposed. To simulate the material nonlinearty including the cracking of concrete, the layer model is adopted, and the initial stress matrix is considered for the simulation of P- effect. After correlation studies with previous numerical results to verify the efficiency of the developed numerical model, many parameter studies are followed, and a regression formula which can give more exact resisting capacity of slender RC columns is introduced on the basis of the obtained numerical results.

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폴리머 침투콘크리트 보의 거동 (Behavior of Polymer-Impregnated Concrete Beams)

  • 변근주;이상민;유동우;이용진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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    • pp.67-73
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    • 1992
  • Polymer-Impregnated Concrete(PIC) is a new polymer-concrete composite material which consist of basic cement concrete and polymer. The mechanical properties and behavior of PIC depend on the type of polymers and the impregnation techniques. In general, the polymer impregnation can improve the strength, durability and ductility of normal concrete. The objective of this study is to develop the analytical procedure for analyzing the structural responces of polymer-impregnated concrete beams with different polymer loading by using finite element method on the basis of experimental results.

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PC장대교량의 정밀안전시공을 위한 시공계측관리시스템의 개발에 관한 연구 (A Study on Development of Monitoring System for Precise Consturction of Large Scale Prestressed Concrete Bridges)

  • 오병환;김의성;최인혁;양인환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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    • pp.520-525
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    • 1996
  • Recently, the prestressed concrete long-span bridegs are increasingly built at various locations in the world. The mechanical and structural behavior of prestressed concrete bridges is very complex because of nonlinear and time-dependent material behavior and sequential change of structural system due to stepwise construction. These factors may cause construction errors with respect to design value and monitoring system is needed to minimize or to protect construction errors. This study presents the basis development of monitoring system for precise construction of large scale prestressed concrete bridges.

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압축링-유막간의 접촉압력 거동에 관한 유한요소해석 (Finite Element Analysis of Contact Pressure Behavior in Compression Ring-Oil Film)

  • 김청균;김한구;한동철
    • Tribology and Lubricants
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    • 제11권4호
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    • pp.53-57
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    • 1995
  • The contact pressure behavior is examined by means of a finite element analysis. The oil film between the piston ring and cylinder liner is analyzed on the basis that it behaves like a polymer material. The calculated results indicate that a shape of sloping edge with a straight line, which is designated as a Model III, shows a good performance on the contact pressure behavior for the increased speed. Obviously, the ring face profiles play an important role on the contact pressure between compression ring and oil film.

Finite element fracture reliability of stochastic structures

  • Lee, J.C.;Ang, A.H.S.
    • Structural Engineering and Mechanics
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    • 제3권1호
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    • pp.1-10
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    • 1995
  • This study presents a methodology for the system reliability analysis of cracked structures with random material properties, which are modeled as random fields, and crack geometry under random static loads. The finite element method provides the computational framework to obtain the stress intensity solutions, and the first-order reliability method provides the basis for modeling and analysis of uncertainties. The ultimate structural system reliability is effectively evaluated by the stable configuration approach. Numerical examples are given for the case of random fracture toughness and load.

시뮬레이션을 이용한 다층 P.C.B. 생산공정의 운영분석 (Analysisi of Multi-Layer P.C.B. Manufacturing Process by Simulation)

  • 김만식
    • 한국시뮬레이션학회논문지
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    • 제1권1호
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    • pp.17-24
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    • 1992
  • The capacity of the drilling process in Multi-Layer PCB fabrication can be affected by various process parameters determining material flows in the unit operations. The ratio of mass-lamination to pin lamination and the number of stacks as the most critical paramaters, among them, were chosen on the basis of exhaustive field evaluation to study their effects on the capacity of the process. The best alternative condition for maximum capacity of the process was selected by simulation of process.

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건설기계 정보화시스템 구축을 위한 운행기록장치 활용방안 (Study on Utilization of Digital Tacho Graph in Construction Machinery Information Systemm)

  • 윤겸주;이승철
    • 자동차안전학회지
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    • 제8권2호
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    • pp.17-23
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    • 2016
  • Construction of our machine "Digital Tacho Graph" toghether with development and intergrated management system information is attached under Traffic Safety Law in article submission. This machine "Digital Tach Graph" has been mandated on a priority basis. The entire machine is constructed with specialised components to collect data that can retrive basic information. To obtain the components to perfect the information to optimize the device and system.