• 한국압력기기공학회 논문집
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• 제19권1호
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• pp.27-35
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• 2023

Pressure tubes are the main components of PHWR core and serve as the pressure boundary of the primary heat transport system. However, because pressure tubes have changed their geometrical dimensions under the severe operating conditions of high temperature, high pressure and neutron irradiation according to the increase of operation time, all dimensional changes should be predicted to ensure that dimensions remain within the allowable design ranges during the operation. Among the deformations, the diameter expansion due to creep leads to the increase of bypass flow which may not contribute to the fuel cooling, the decrease of critical channel power and finally the deration of the power to maintain the operational safety margin. This study is focused on the modeling of the expansion of the pressure tube diameter based on the operating conditions and measured diameter data. The pressure tube diameter expansion was modeled using the neutron flux and temperature distributions of each fuel channel and each fuel bundle as well as the measured diameter data. Although the basic concept of the current modeling approach is simple, the diameter prediction results using the developed methodology showed very good agreement with the real data, compared to the existing methodology.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.3-4
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• 2002

The stainless steel sheathed MgB$_2$ tapes with Cu addition were fabricated by PIT method without heat treatment. The $J_{c}$ value of 5,600 A/ $cm^{2}$and 16,000 A/$cm^{2}$ at 4.2 K and 5 T were obtained for the $MgB_{2}$ tape and 10 vol % of Cu added $MgB_{2}$ tape respectively. The $J_{c}$-B curve shows enhancement in J$_{c}$ under magnetic field, which suggests enhancement in flux pinning property with Cu addition.n.

• Toxicological Research
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• 제29권3호
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• pp.165-172
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• 2013

Acetaminophen (APAP) known as paracetamol is the main ingredient in Tylenol, which has analgesic and anti-pyretic properties. Inappropriate use of APAP causes major morbidity and mortality secondary to hepatic failure. Overdose of APAP depletes the hepatic glutathione (GSH) rapidly, and the metabolic intermediate leads to hepatocellular death. This article reviews the mechanisms of hepatotoxicity and provides an overview of current research studies. Pharmacokinetics including metabolism (activation and detoxification), subsequent transport (efflux)-facilitating excretion, and some other aspects related to toxicity are discussed. Nuclear factor erythroid 2-related factor 2 (Nrf2)-regulated gene battery plays a critical role in the multiple steps associated with the mitigation of APAP toxicity. The role of Nrf2 as a protective target is described, and potential natural products inhibiting APAP toxicity are outlined. This review provides an update on the mechanism of APAP toxicity and highlights the beneficial role of Nrf2 and specific natural products in hepatoprotection.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.645-651
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• 2004

For the connection of trans-continental railway network, it is critical to conquer the break-of-gauge problem at the borders in different countries. Up to now, the best solution seems to be the employ of the auto-changable gauge equipment. Countries, such as Russia, Japan are developing and commercializing auto-changable gauge equipment to maximize transport efficiency for the trans-continental network. The efforts to search a suitable logistical service are also underway. In this paper, technology and development trend of this equipment in several countries is indicated through inspecting and analyzing the historical and current situation of development, operating mechanism and technical problems. As the basic technology of auto-changeable gauge is not well developed in our country, the purpose of this study is to search an approach to fix the research direction, and find practical ways to international cooperation.

• 전기학회논문지P
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• 제63권1호
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• pp.19-23
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• 2014

This paper describes the electron transport characteristics in $SF_6$-He gas calculated E/N values 0.1~700[Td] by the Monte Carlo simulation and Boltzmann equation method using a set of electron collision cross sections determined by the authors and the values of electron swarm parameters obtained by TOF method. This study gained the values of the electron swarm parameters such as the electron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients for $SF_6$-He gas at a range of E/N. A set of electron collision cross section has been assembled and used in Monte Carlo simulation to predict values of swarm parameters. The result of Boltzmann equation and Monte Carlo Simulation has been compared with experimental data by Ohmori, Lucas and Carter. The swarm parameter from the swarm study are expected to sever as a critical test of current theories of low energy scattering by atoms and molecules.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2001년도 High Temperature Superconductivity Vol.XI
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• pp.62-62
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• 2001

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.397-397
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• 2011

In a low aspect ratio (LAR) tokamak reactor with a superconducting toroidal field (TF) coil, the radial build of TF coil and the shield play a key role in determining the size of a reactor. For self-consistent determination of the reactor components and physics parameters, a system analysis code is coupled with one-dimensional radiation transport code. Conceptual design study of a compact superconducting LAR tokamak reactor with aspect ratio less than 2.5 was conducted and the optimum radial build was identified. It is shown that the use of an improved shielding material and high temperature superconducting magnets with high critical current density opens up the possibility of a fusion power plant with compact size and small re-circulating power simultaneously at low aspect ratio, and that by using an inboard neutron reflector instead of breeding blanket, tritium self-sufficiency is possible with outboard blanket only and thus compact sized reactor is viable.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 전문대학교육위원
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• pp.89-92
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• 2005

Using quantitative simulations of weakly ionized plasma, we can analyze gas characteristic. In this paper, the electron transport characteristic in $CH_4$ has been analysed over the E/N range 0.1${\sim}$ 300(Td), at the 300($_{\circ}$ K) by the two term approximation Boltzmann equation method and Monte Carlo Simulation. The electron energy distribution function has been analysed in $CH_4$ at E/N=10, 100 for a case of the equilibrium region in the mean energy. The result of Boltzmann equation and Monte Carlo Simulation has been compared with experimental data by Ohmori, $Lucas^{[18]}$ and Carter. The swarm parameter from the swarm study are expected to sever as a critical test of current theories of low energy scattering by atoms and molecules.

• 천문학회보
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• 제36권1호
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• pp.33.1-33.1
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• 2011

The plasma sheet of the Earth's magnetosphere is a sheet of hot plasmas in the magnetotail region, dividing the two (northern and southern) lobes of the Earth's magnetic field. It is the key region that is often closely linked to various electromagnetic dynamics in the Earth's magnetosphere-ionosphere system. In particular, it is the region that is most crucial for substorms, which is one of the most dynamic phenomena in the Earth's magnetosphere. The question of substorm triggering remains highly controversial until today, and at the center of the controversy there are several critical physics issues of the plasma sheet. In this talk I will introduce some of the physics issues of the plasma sheet. The specific topics that this talk will cover are (i) the general properties of the plasma sheet, (ii) fast plasma jets and plasma transport problem, (iii) stability/instability problem, and (iv) effects of thin current sheet. I will also present some of our group's recent findings regarding these topics, as obtained by comprehensive analyses of various observational data. The level and content of this talk are designed to be comprehensible to not only space physicists but also the scientists in a related field such as solar and heliospheric physics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
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• pp.102-105
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• 2002

In this paper, the electron transport characteristics in $CF_4$ has been analysed over the E/N range 1${\sim}$300 [Td] by a two-term approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity, longitudinal diffusion coefficient, the ratio of the diffusion coefficient to the mobility, electron ionization and attachment coefficients, effective ionization coefficient, mean energy, collision frequency and the electron energy distribution function. The swarm parameter from the swarm study are expected to serve as a critical test of current theories of low energy electron scattering by atoms and molecules, in particular, as well as crucial information for quantitative simulations of weakly ionized plasmas.