• 제목/요약/키워드: complex geometry

검색결과 757건 처리시간 0.026초

Crystal Structure and Characterization of a New Eight Coordinated Cadmium Complex

  • Hakimi, Mohammad;Moeini, Keyvan;Mardani, Zahra;Khorrami, Farzaneh
    • 대한화학회지
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    • 제57권3호
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    • pp.352-356
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    • 2013
  • In this work, a new cadmium complex $[Cd(L)(CH_3COO)_2].2H_2O$ (1) with the ligand L, N,N'-bis(2-pyridinecarboxalidene)-1,2-cyclohexanediamine was prepared and identified by elemental analysis, FT-IR, Raman, $^1H$ NMR spectroscopy and single-crystal X-ray diffraction. The cadmium atom in the crystal structure of 1 has distorted triangular dodecahedral geometry by coordination of the four nitrogen atoms of L and four oxygen atoms of the two acetate ions. Two water molecules are also incorporated in the crystal network. The $O-H{\cdots}O$ hydrogen bonds present in the crystal structure of 1. In this work, three structural surveys including coordination numbers of the cadmium atom, coordination modes of L and resonance in pyridine-2-ylmethanimine-based compounds are presented.

고속 가공용 엔드밀의 형상설계에 관한 연구 (Study on the Design of End Mill Geometry for the High Speed Machining)

  • 이상규;배승민;고성림;김경배;서천석
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.67-70
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    • 2001
  • The tool geometry parameters and cutting process have complex relationships. Until now, numerous cutting tests were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter(rake angle, clearance angle, length of cutter) and cutting process(cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining

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고속가공용 엔드밀 형상설계 S/W 개발 (Development of Geometric Design S/W for High Speed End Mill)

  • 한창규;고성림;서천석;김경배
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 추계학술대회 논문집
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    • pp.422-427
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    • 2004
  • The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining and to develop a software for design of end mill geometry.

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Material structure generation of concrete and its further usage in numerical simulations

  • Husek, Martin;Kala, Jiri
    • Structural Engineering and Mechanics
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    • 제68권3호
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    • pp.335-344
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    • 2018
  • The execution of an experiment is a complex affair. It includes the preparation of test specimens, the measurement process itself and also the evaluation of the experiment as such. Financial requirements can differ significantly. In contrast, the cost of numerical simulations can be negligible, but what is the credibility of a simulated experiment? Discussions frequently arise concerning the methodology used in simulations, and particularly over the geometric model used. Simplification, rounding or the complete omission of details are frequent reasons for differences that occur between simulation results and the results of executed experiments. However, the creation of a very complex geometry, perhaps all the way down to the resolution of the very structure of the material, can be complicated. The subject of the article is therefore a means of creating the material structure of concrete contained in a test specimen. Because a complex approach is taken right from the very start of the numerical simulation, maximum agreement with experimental results can be achieved. With regard to the automation of the process described, countless material structures can be generated and randomly produced samples simulated in this way. Subsequently, a certain degree of randomness can be observed in the results obtained, e.g., the shape of the failure - just as is the case with experiments. The first part of the article presents a description of a complex approach to the creation of a geometry representing real concrete test specimens. The second part presents a practical application in which the numerical simulation of the compressive testing of concrete is executed using the generated geometry.

금속이온 착체에 의한 G4-48PyP 덴드리머 LB막의 전기적 특성 (Electrical Properties of G4-48PyP Dendrimer LB Films complex with Metal Ions)

  • 정상범;유승엽;박재철;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.769-772
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    • 2002
  • Dendrimers are well-defined macromolecules exhibiting a tree-like structure, first derived by the cascade molecule approach. Peculiar features of the dendritic geometry are the large number of end groups as well as the shape persistence in higher generations, approaching spherical geometry. And one of the most peculiar characteristics of dendritic macromolecules is their controlled molecular structure and orientation, which means that they have a practical application in achieving a highly organized molecular arrangement. We attempted to fabricate a dendrimer LB films containing 48 pyridinepropanol functional end group. As the pyridinepropanol functional group could form a complex structure with metal ions. We investigated the surface activity of dendrimer films at air-water interface compared with pure dendrimer and its complex with $Fe^{2+}$ ions into subphase. We though that metal ions are contributed to networking or branching reaction between dendrimers. And we expected that it can result in the differences on the electrical properties. We have studied the electrical properties of the ultra thin dendrimer LB films investigated by the current-voltage characteristics of metal dendrimer LB films/metal (MIM) structure.

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신속성형기술 전용 벌집구조 형상 모델링 기술 개발 (Geometric Modeling of Honeycomb Structural Geometry for Solid Freeform Fabrication)

  • 지해성
    • 한국CDE학회논문집
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    • 제4권3호
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    • pp.180-189
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    • 1999
  • Solid freeform fabrication technology, widely known as rapid prototyping an rapid tooling, can create physical part directly from digital model by accumulating layers of a given material. Providing a tremendous flexibility of a part geometry that they can fabricate, these technologies present a opportunity or the creation of new products that can not be made with existing technologies. For this to be possible, however, various design environments including different fabrication processes needs to be considered at the time of design, and finding an appropriate design solution for the new product by combining necessary design communications become increasingly complex as environmental condition become diverse. This paper proposes a geometric modeling paradigm for design and fabrication of a new product, honeycomb structural geometry.

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최적형상의 고속용 엔드밀 설계를 위한 프로그램 개발 (Development of the program for Optimal Design of High Speed Endmill)

  • 고성림;한창규;서천석;김경배
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2003년도 춘계학술대회 논문집
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    • pp.500-503
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    • 2003
  • The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining

  • PDF