• Title/Summary/Keyword: high energy physics

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Azo-Dyes Photo-Aligning; Physics and Applications

  • Chigrinov, V.G.;Kwok, H.S.;Takada, Hirokazu;Takatsu, Haruyoshi
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.759-763
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    • 2005
  • This review presents the status of our research in liquid crystal display (LCD) photo-aligning. We present the basic mechanisms of the photo-induced order in various photo-aligning materials and in azo-dye layers in particular and show that photo-aligning methods can provide a controllable pretilt angle and anchoring energy of the liquid crystal cell, as well as its high thermo and UV stability. The photo-aligning of various types of liquid crystal displays is also discussed.

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A Grid Implementation for High-Energy Physics Study (고에너지물리연구를 위한 그리드의 구축)

  • 조기현;오영도;권기환;한대희;손동철;김복주;이상산
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.04a
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    • pp.55-57
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    • 2003
  • 고에너지물리연구에서는 입자가속기에서 배출되는 막대한 양의 데이터를 저장, 처리하기 위한 계산능력과 대용량의 저장장치를 확보하는데 어려움을 겪어왔다. 또한, 실제 실험에 참여, 연구, 분석하는 인력 또한 전세계에 흩어져 있어 실험의 효율성을 떨어뜨리고 있다. 이러한 어려움을 해결하고자 차세대 인터넷이라 불리는 그리드를 활용하여 고에너지연구에서 필요로 하는 계산자원과 저장장치, 데이터에 대한 접근성 등을 확보한다는 방안이다. 이 글에서는 CERN에서 개발한 EU-DataGrid 소프트웨어를 이용한 고에너지물리 데이터 그리드의 구축 상황을 기술하였다.

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FINITE TIME BLOWUP FOR THE FOURTH-ORDER NLS

  • Cho, Yonggeun;Ozawa, Tohru;Wang, Chengbo
    • Bulletin of the Korean Mathematical Society
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    • v.53 no.2
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    • pp.615-640
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    • 2016
  • We consider the fourth-order $Schr{\ddot{o}}dinger$ equation with focusing inhomogeneous nonlinearity ($-{\mid}x{\mid}^{-2}{\mid}u{\mid}^{\frac{4}{n}}u$) in high space dimensions. Extending Glassey's virial argument, we show the finite time blowup of solutions when the energy is negative.

ENHANCED GAMMA RAY FLUX FROM THE GENERAL DIRECTION OF THE VIRGO GALAXY CLUSTER

  • FATEMI S. J.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.57-58
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    • 1996
  • There is an excess gamma flux from the general direction of the Galactic North Pole compared with that from the south when allowance is made for the contribution from CR interactions with the HI gas (Osborne et al., 1994). The extent to which it is in accord with the predictions of Wdowczyk and Wolfendale (1990 a,b) for gamma rays secondary to very high energy CR escaping from the VIRGO cluster is examined and it is claimed that the observations may well be of the order of those expected.

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A Study on the absorbed dose to water for high energy electron beams using Water equivalency of plastic phantom (고 에너지 전자선에서 물등가 고체팬톰을 이용한 물 흡수선량 측정에 관한 연구)

  • Sin, Dong-Ho;Sin, Dong-Oh;Kim, Sung-Hoon;Park, Sung-Yong;Ji, Young-Hoon;Ahn, Hee-Kyung;Kang, Jin-Oh;Hong, Seong-Eon
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2004.11a
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    • pp.166-169
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    • 2004
  • In the International Code of Practice for dosimetry TRS-398 published by International Atomic Energy Agency(IAEA), water equivalency plastic phantom may be used under certain circumstances for electron beam dosimetry for beam quality E0${\leq}$ 10 MeV. In this study, Palstic Water$^{TM}$ and Virtual Water$^{TM}$ were evaluated in order to determine fluence scaling factor hpl. Plastic phantom was evaluated for five electron energy from 6 MeV to 20 MeV. From the measured data of Palstic Water$^{TM}$, the fluence scaling factor hpl was found to be average 0.9964 and Virtual Water$^{TM}$ fluence scaling factor was 1.0156.

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New composites based on low-density polyethylene and rice husk: Elemental and thermal characteristics

  • Anshar, Muhammad;Tahir, Dahlang;Makhrani, Makhrani;Ani, Farid Nasir;Kader, Ab Saman
    • Environmental Engineering Research
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    • v.23 no.3
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    • pp.250-257
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    • 2018
  • We developed new composites by combining the solid waste from Low-Density Polyethylene in the form of plastic bag (PB) and biomass from rice husk (RH),in the form of $(RH)_x(PB)_{1-x}$ (x = (1, 0.9, 0.7, 0.5)), as alternative fuels for electrical energy sources, and for providing the best solution to reduce environmental pollution. Elemental compositions were obtained by using proximate analysis, ultimate analysis, and X-ray fluorescence spectroscopy, and the thermal characteristics were obtained from thermogravimetric analysis. The compositions of carbon and hydrogen from the ultimate analysis show significant increases of 20-30% with increasing PB in the composite. The activation energy for RH is 101.22 kJ/mol; for x = 0.9 and 0.7, this increases by 4 and 6 magnitude, respectively, and for x = 0.5, shows remarkable increase to 165.30 kJ/mol. The range of temperature of about $480-660^{\circ}C$ is required for combustion of the composites $(RH)_x(PB)_{1-x}$ (x = (1, 0.9, 0.7, 0.5)) to perform the complete combustion process and produce high energy. In addition, the calorific value was determined by using bomb calorimetry, and shows value for RH of 13.44 MJ/kg, which increases about 30-40% with increasing PB content, indicating that PB has a strong effect of increasing the energy realized to generate electricity.

Inplementation of a Hydrogen Leakage Simulator with HyRAM+ (HyRAM+를 이용한 수소 누출 시뮬레이터 구현)

  • Sung-Ho Hwang
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.1
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    • pp.551-557
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    • 2024
  • Hydrogen is a renewable energy source with various characteristics such as clean, carbon-free and high-energy, and is internationally recognized as a "future energy". With the rapid development of the hydrogen energy industry, more hydrogen infrastructure is needed to meet the demand for hydrogen. However, hydrogen infrastructure accidents have been occurring frequently, hindering the development of the hydrogen industry. HyRAM+, developed by Sandia National Laboratories, is a software toolkit that integrates data and methods related to hydrogen safety assessments for various storage applications, including hydrogen refueling stations. HyRAM+'s physics mode simulates hydrogen leak results depending on the hydrogen refueling station components, graphing gas plume dispersion, jet frame temperature and trajectory, and radiative heat flux. In this paper, hydrogen leakage data was extracted from a hydrogen refueling station in Samcheok, Gangwon-do, using HyRAM+ software. A hydrogen leakage simulator was developed using data extracted from HyRAM+. It was implemented as a dashboard that shows the data generated by the simulator using a database and Grafana.

Growth of Ti on Si(111)-)-$7{\times}7$ Surface and the Formation of Epitaxial C54 $TiSi_2$ on Si(111) Substrate (Si(111)-$7{\times}7$ 면에서 Ti 성장과 C54 $TiSi_2$/Si(111) 정합 성장에 관하여)

  • Kun Ho Kim;In Ho Kim;Jeoung Ju Lee;Dong Ju Seo;Chi Kyu Choi;Sung Rak Hong;Soo Jeong Yang;Hyung Ho Park;Joong Hwan Lee
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.67-72
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    • 1992
  • The growth of Ti on Si(111)-$7{\times}7$ and the formation of epitaxial C54 $TiSi_2$ were investigated by using reflection high energy electron diffraction(RHEED) and high resolution transmission electron microscopy(HRTEM). Polycrystalline Ti layer is grown on the amorphous Ti-Si interlayer which is formed at the Ti/Si interface by Ti deposition on Si(111)-$7{\times}7$ at room temperature (RT). HRTEM lattice image and transmission electron diffraction(TED) showed that epitaxial C54 $TiSi_2$ grown on Si substrate with 160 ML of Ti on Si(111)-$7{\times}7$ surface at RT, followed by annealing at $750^{\circ}C$ for 10 min in UHV. Thin single crystal Si overlayer with [111] direction is grown on $TiSi_2$ surface when $TiSi_2$/Si(111) is annealed at ${\sim}900^{\circ}C$ in UHV, which was confirmed by Si(111)-$7{\times}7$ superstructure.

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Electronic, Optical and Electrical Properties of Nickel Oxide Thin Films Grown by RF Magnetron Sputtering

  • Park, Chanae;Kim, Juhwan;Lee, Kangil;Oh, Suhk Kun;Kang, Hee Jae;Park, Nam Seok
    • Applied Science and Convergence Technology
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    • v.24 no.3
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    • pp.72-76
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    • 2015
  • Nickel oxide (NiO) thin films were grown on soda-lime glass substrates by RF magnetron sputtering method at room temperature (RT), and they were post-annealed at the temperatures of $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$ and $400^{\circ}C$ for 30 minutes in vacuum. The electronic structure, optical and electrical properties of NiO thin films were investigated using X-ray photoelectron spectroscopy (XPS), reflection electron energy spectroscopy (REELS), UV-spectrometer and Hall Effect measurements, respectively. XPS results showed that the NiO thin films grown at RT and post annealed at temperatures below $300^{\circ}C$ had the NiO phase, but, at $400^{\circ}C$, the nickel metal phase became dominant. The band gaps of NiO thin films post annealed at temperatures below $300^{\circ}C$ were about 3.7 eV, but that at $400^{\circ}C$ should not be measured clearly because of the dominance of Ni metal phase. The NiO thin films post-annealed at temperatures below $300^{\circ}C$ showed p-type conductivity with low electrical resistivity and high optical transmittance of 80% in the visible light region, but that post-annealed at $400^{\circ}C$ showed n-type semiconductor properties, and the average transmittance in the visible light region was less than 42%. Our results demonstrate that the post-annealing plays a crucial role in enhancing the electrical and optical properties of NiO thin films.