• 제목/요약/키워드: Nanoscale Structure

검색결과 159건 처리시간 0.044초

Mixture rule for studding the environmental pollution reduction in concrete structures containing nanoparticles

  • Tabatabaei, Javad;Nourbakhsh, Seyed Hesam;Siahkar, Mahdi
    • Coupled systems mechanics
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    • 제9권3호
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    • pp.281-287
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    • 2020
  • Nanotechnology is an upcoming technology that can provide solution for combating pollution by controlling shape and size of materials at the nanoscale. This review provides comprehensive information regarding the role of nanotechnology in pollution control at concrete structures. Titanium dioxide (TiO2) nanoparticles are a good item for concrete structures for diminishing the air polluting affect by gasses of exhaust. In this article, the mixture rule is presented for the effect of nanoparticles in environmental pollution reduction in concrete structures. The compressive strength, elastic modulus and reduction of steel bars in the concrete structures are studied. The Results show that TiO2 nanoparticles have significant effect on the reduction of environmental pollution and increase of stiffness in the concrete structures. In addition, the nanoparticles can reduce the use of steel bars in the concrete structure.

블록 공중합체를 이용한 CoCrPt 나노점 배열의 자기적 성질 연구 (MAGNETIC PROPERTIES OF CoCrPt NANODOTS ARRAY MADE BY PS-PMMA BLOCK COPOLYMER TEMPLATE)

  • Jeong, Jong-Ryul;Im, Mi-Young;Shin, Sung-Chul;Park, Dae-Geun;Kwon, Ki-Young;Jung, Hee-Tae;Yang, Seung-Man
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2002년도 동계연구발표회 논문개요집
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    • pp.34-35
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    • 2002
  • CoCrPt alloy films are attracting wide attention for applications to high-density magnetic recording media and hard magnetic layer in spin valve structure due to their high coercivity and strong magnetocrystalline anisotropy. Diblock copolymer templates are one of the most promising candidates for nanoscale patterning otherwise inaccessible by lithographic procedures [1]. In this study, we have investigated magnetic properties of Co$\sub$68/Cr$\sub$18/Pt$\sub$14/ nanodot arrays made by self-assembling polystyrene-block-methyl methacrylate ((PS-b-PMMA), (Mn = 82.5 Kg/mol, with a 1.12 polydispersity)) diblock copolymer. (omitted)

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Voltage Optimization of Power Delivery Networks through Power Bump and TSV Placement in 3D ICs

  • Jang, Cheoljon;Chong, Jong-Wha
    • ETRI Journal
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    • 제36권4호
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    • pp.643-653
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    • 2014
  • To reduce interconnect delay and power consumption while improving chip performance, a three-dimensional integrated circuit (3D IC) has been developed with die-stacking and through-silicon via (TSV) techniques. The power supply problem is one of the essential challenges in 3D IC design because IR-drop caused by insufficient supply voltage in a 3D chip reduces the chip performance. In particular, power bumps and TSVs are placed to minimize IR-drop in a 3D power delivery network. In this paper, we propose a design methodology for 3D power delivery networks to minimize the number of power bumps and TSVs with optimum mesh structure and distribute voltage variation more uniformly by shifting the locations of power bumps and TSVs while satisfying IR-drop constraint. Simulation results show that our method can reduce the voltage variation by 29.7% on average while reducing the number of power bumps and TSVs by 76.2% and 15.4%, respectively.

수퍼커패시터용 Co/PVA복합전극의 전기화학적특성 (Electrochemical characteristics of Co/PVA composite electrode for supercapacitor)

  • 이희우;김한주;;박수길
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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    • pp.577-580
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    • 2001
  • Very fine cobalt oxide ambigel powder were prepared using a unique solution chemistry associated with the sol-gel process. The mesoporous structure of the initial gel is maintained by removing fluid under conditions where the capillary forces that result extraction are either low or no existent, are either low or nonexistent. Controling both the pore and solid architecture on the nanoscale offers a strategy for the design of supercapacitor. But $CoO_{x}$ have the low voltage, so we experiment using CO/PVA composite electrode.

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다양한 합성방법으로 제조된 망간옥사이드 전극들의 수퍼커패시터에 대한 응용 (Application on Supercapacitor of Manangese Oxide Electrodes Prepared by Various Synthesis Methods)

  • 김한주;신달우;김용철;김성호;박수길
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.606-609
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    • 2000
  • We describe the preparation of a manganese oxide polymorph in which the solid-pore architecture of the material is controllably varied. All MnO$_2$ gels derived from a KMnO$\_$4/-based sol-gel synthesis. The mesoporous structure of the initial gel is maintained by removingore fluid under conditions where the capillary forces that result fro extraction are either low or no existent. are either low or noexistent. Controlling both the pore and solid architecture on the nanoscale offers a strategy for the design of supercapacitor.

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Micro Metal Injection Molding Using Hybrid Micro/Nano Powders

  • Nishiyabu, Kazuaki;Kakishita, Kenichi;Osada, Toshiko;Tanaka, Shigeo
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.36-37
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    • 2006
  • This study aims to investigate the usage of nano-scale particles in a micro metal injection molding ($\mu$-MIM) process. Nanoscale particle is effective to improve transcription and surface roughness in small structure. Moreover, the effects of hybrid micro/nano particles, Cu/Cu and SUS/Cu were investigated. Small dumbbell specimens were produced using various feedstocks prepared by changing binder content and fraction of nano-scale Cu particle (0.3 and $0.13{\mu}m$ in particle size). The effects of adding the fraction of nano-scale Cu powder on the melt viscosity of the feedstock, microstructure, density and tensile strength of sintered parts were discussed.

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Programmable Metallization Cell에서 칼코게나이드 물질의 열처리에 따른 특성 (Properties on Annealing of Chalcogenide Materials at Programmable Metallization Cell)

  • 최혁;김현구;남기현;구용운;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.164-164
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    • 2007
  • Photodiffusion of silver into chalcogenide thin film is one of the most interesting effects that occurs in chalcogenide glass as it theatrically changes the properties of the initial material and forms a ternary. Programmable Metallization Cell(PMC) Randon Access Memory use for photodiffusion of mobile metal is based on the electrochemical growth and removal of nanoscale metallic pathway in thin film of solid electrolyte. This paper investigates the annling properties on Ag-doped $Ge_{25}Se_{75}$ thin film structure and describes the electrical characteristics of PMC-RAM. The composition of the intercalation products containing Ag is confirmed using X-ray diffraction which shows the formation of Ag-doped $Ge_{25}Se_{75}$.

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Transparent Conducting Nanodomes for Efficient Light Management

  • Hong, Seung-Hyouk;Yun, Ju-Hyung;Park, Hyeong-Ho;Kim, Joondong
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.314.1-314.1
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    • 2013
  • Transparent conducting nanoscale-domes were periodically patterned on a Si substrate by nanoimprint method. Transparent conductor of indium-tin-oxide (ITO) was shaped as a nanodome, which effectively drives the incident light effectively into a light-absorber and therefore induces a substantially enhanced photo-response. An ITO nanodome is electrically isolated from the neighboring nanodomes. This structure benefits to provide a low contact between a Si substrate and a front metal electrode giving an efficient electrical path. The ITO nanodome device showed a significantly enhanced photo-response of 6010 from the value of 72.9 of a planar ITO film. The electrical and optical advantage of an ITO nanodome is suitable for various photoelectric applications.

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Large amplitude free torsional vibration analysis of size-dependent circular nanobars using elliptic functions

  • Nazemnezhad, Reza;Rabiei, Mohaddese;Shafa'at, Pouyan;Eshaghi, Mehdi
    • Structural Engineering and Mechanics
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    • 제77권4호
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    • pp.535-547
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    • 2021
  • This paper concerns with free torsional vibration analysis of size dependent circular nanobars with von kármán type nonlinearity. Although review of the literature suggests several studies employing nonlocal elasticity theory to investigate linear torsional behavior, linear/nonlinear transverse vibration and buckling of the nanoscale structures, so far, no study on the nonlinear torsional behavior of the nanobars, considering the size effect, has been reported. This study employs nonlocal elasticity theory along with a variational approach to derive nonlinear equation of motion of the nanobar. Then, the nonlinear equation is solved using the elliptic functions to extract the natural frequencies of the structure under fixed-fixed and fixed-free end conditions. Finally, the natural frequencies of the nanobar under different nanobar lengths, diameters, nonlocal parameters, and amplitudes of vibration are reported to illustrate the effect of these parameters on the vibration characteristics of the nanobars. In addition, the phase plane diagrams of the nanobar for various cases are reported.

분자동역학을 이용한 다양한 구조물 위의 수액적의 특성에 대한 연구 (A Study of Characteristics of Water Droplets on Various Nanoscale Structures Using Molecular Dynamics)

  • 이광호;권태우;하만영
    • 설비공학논문집
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    • 제30권1호
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    • pp.33-43
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    • 2018
  • This study numerically investigated statistic and dynamic behaviors of the water droplet on plate with or without various structured-pillars at nano-scale by molecular dynamics simulation. This study considered smooth plate, plate with the rectangular-structured pillar, and the plate with dual-structured pillar under various characteristic energy conditions. The static behavior of water droplet depending on the plate shape, plate surface energy, and the pillar characteristics were examined. After the water droplet reaches its steady state, this study investigated the dynamic behavior of the water droplet by applying a constant force. Finally, this study investigated the static and dynamic behaviors of the water droplet by measuring its contact angle and contact angle hysteresis. As a result, we found that the structure was more hydrophobic.