• 제목/요약/키워드: L.W.O.S.T

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The Analysis ol Temperature Distribution by the Fuse Element Shape (퓨우즈 엘리먼트의 형상에 따른 온도분포해석)

  • Park, D.K.;Lee, S.H.;Kim, Y.R.;Choi, T.S.;Lee, J.C.;Park, K.B.;Koo, K.W.;Kim, J.S.;Han, S.O.
    • Proceedings of the KIEE Conference
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    • 대한전기학회 1996년도 하계학술대회 논문집 C
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    • pp.1688-1690
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    • 1996
  • In this paper, by using the Finite Element Method, we analysed the melting and clearing characteristic of fuse elments shapes. The melting characteristics and the effects of temperature conduction by fuse element shames was studied. We compared the actul testing results by the clearing device with the simulation result.

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Temperature Dependent Characteristics of a Combined Discharge Type Ozonizer (CDO)

  • Fayzur Rahman;B. J. Chun;Lee, K. S.;Lee, D. I.
    • KIEE International Transactions on Electrophysics and Applications
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    • 제3C권3호
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    • pp.106-112
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    • 2003
  • A combined discharge type ozonizer was designed and manufactured. The increase or decrease of temperature greatly influences the characteristics of ozone concentration ( $O_{3con}$), ozone generation ( $O_{3g}$) and ozone yield ( $O_{3Y}$) of a discharge type ozonizer. The characteristics of ozone concentration, ozone generation and ozone yield rate were investigated by varying the gas flow rate (Q), the discharge power ( $W_{d}$) and the temperature (T). At T=25[$^{\circ}C$] the values of $O_{3con}$ were found as 5632, 4200, 2500 and l800[ppm] at Q = 1, 2, 4 and 6[l/min] respectively. At the same temperature the corresponding values of $O_{3g}$ were found as 662, 988, 1176 and l270[mg/h] and those of $O_{3Y}$ were found as 67, 102, 119 and 135[g/kWh] respectively. When the temperature is decreased to -50[$^{\circ}C$], the values of $O_{3con}$ were found as 9000, 6700, 4000 and 2800[ppm] respectively at Q = 1, 2, 4 and 6[l/min]. At the same value of temperature the corresponding values of $O_{3g}$ were found as 1220, 1576, 1882 and 2050[mg/h] and those of $O_{3Y}$ were found as 120, 159, 188 and 202[g/kWh] respectively. Hence as the temperature was decreased from 25 to -50[$^{\circ}C$], the efficiencies of ozone generation were increased by 79, 55, 58 and 49[%] respectively at Q = 1, 2, 4 and 6[l/min].]. 6[l/min].].

Solid-liquid phase equilibria on the GdBa2Cu3O7-δ stability phase diagram in low oxygen pressures (1 - 100 mTorr)

  • Lee, J.W.;Lee, J.H.;Moon, S.H.;Yoo, S.I.
    • Progress in Superconductivity and Cryogenics
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    • 제14권4호
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    • pp.28-31
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    • 2012
  • We report the solid-liquid phase equilibria on the $GdBa_2Cu_3O_{7-{\delta}}$ (GdBCO) stability phase diagram in low oxygen pressures ($PO_2$) ranging from 1 to 100 mTorr. On the basis of the GdBCO stability phase diagram experimentally determined in low oxygen pressures, the isothermal sections of three different phase fields on log $PO_2$ vs. 1/T diagram were schematically constructed within the $Gd_2O_3-Ba_2CuO_y-Cu_2O$ ternary system, and the solid-liquid phase equilibria in each phase field were described. The invariant points on the phase boundaries include the following three reactions; a pseudobinary peritectic reaction of $GdBCO{\leftrightarrow}Gd_2O_3$ + liquid ($L_1$), a ternary peritectic reaction of $GdBCO{\leftrightarrow}Gd_2O_3+GdBa_6Cu_3O_y$ + liquid ($L_2$), and a monotectic reaction of $L_1{\leftrightarrow}GdBa_6Cu_3O_y+L_2$. A conspicuous feature of the solid-liquid phase equilibria in low $PO_2$ regime (1 - 100 mTorr) is that the GdBCO phase is decomposed into $Gd_2O_3+L_1$ or $Gd_2O_3+GdBa_6Cu_3O_y+L_2$ rather than $Gd_2BaCuO_5+L$ well-known in high $PO_2$ like air.

Effect of AC Electric Field on Decreasing Liftoff Height in Laminar Lifted Jet Flames (층류 부상 화염의 화염부상 높이 감소 구간에서 교류 전기장이 인가된 화염에 관한 영향)

  • Seo, B.H.;Van, K.H.;Kim, G.T.;Park, J.;Keel, S.I.;Kim, S.W.;Chung, S.H.
    • Journal of the Korean Society of Combustion
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    • 제22권3호
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    • pp.17-22
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    • 2017
  • An experimental study has been conducted to elucidate the effect of AC electric field on behaviors of laminar lifted flame in nitrogen-diluted methane coflow-jets. Our concerns are focued on the regime to show a decrease in liftoff height, $H_L$ with increasing nozzle exit velocity, $U_O$ (hereafter, $decreasing-H_L$). The $H_L$ with $U_O$ near flame extinction were measured by varying the applied AC voltage, $V_{AC}$ and frequency, $f_{AC}$ in a single electrode configuration. The behavior of $H_L$ with a functional dependency of $V_{AC}$ and $f_{AC}$ was categorized into two regime : (I) $H_L$ decreased for nozzle diameter, D = 1.0 mm, and (II) $H_L$ increased in the increase of $f_{AC}$ for a fixed $V_{AC}$ in a D = 4.0, 8.4 mm. The lifted flames in $decreasing-H_L$ region was unstable in high voltage regimes while the $H_L$ showed a decreasing tendency with $U_O$ except them. Such behaviors in $H_L$ were also characterized by functional dependencies of related physical parameters such as $V_{AC}$, $f_{AC}$, $U_O$, fuel mole fraction ($X_{F.O}$) and D.

Clinical Study on 1 Case of patient with Urinary Retention (요폐환자(尿閉患者) 1례(例)에 대한 임상적(臨床的) 고찰(考察))

  • Kim, Jae-Hyeng;Cho, Chung-Sik;Kim, Chul-Jung
    • Journal of Haehwa Medicine
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    • 제14권1호
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    • pp.43-49
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    • 2005
  • One case of patient with urinary retention was reported in this clinical study. After the study, the results were as follows: 1. Anulesis belongs to l$\acute{o}$ng-bi(癃閉) in oriental medicine and the patient of this case belongs to chronic anulesis. 2. The patient of this case was thought as broke out anuresis by vesical nerve palsy of diabetic bladder pathy and sequela of stroke, and ischuria of long lie down 3. The patient of this case changeable process is supposed to urinary frequency, 'bi(閉)', 'l$\acute{o}$ong(癃)', urinary incontinence and urinary frequency. 4. First time of drug treatment is GAMIPHALJENG-SAN(ji$\bar{a}$-w$\grave{e}$i-b$\bar{a}$-h$\bar{e}$ng-s$\check{a}$n) by oral administration that action of alleviate a fever, water utilization and metaphase, convalescence time of drug treatment is PHALMIWANGAMI (b$\bar{a}$-w$\grave{e}$i-w$\acute{a}$n-ji$\bar{a}$-w$\grave{e}$i), YIKLUENG-TANG(yi-ling-t$\bar{a}$ng), CHUKYOO-TANG(s$\grave{u}$-ni$\grave{a}$o-t$\bar{a}$ng) that action of recreation. 5. Accupuncture treatment is s$\bar{a}$n-x$\bar{i}$ng-xuw$\acute{e}$, zw$\acute{u}$-s$\bar{a}$n-li, qi-h$\check{a}$i, gu$\bar{a}$n-yu$\acute{a}$n, zh$\bar{o}$ng-ji by mild supplementing and reducing manipulation of needle and heat accupuncture is qi-h$\check{a}$i, gu$\bar{a}$n-yu$\acute{a}$n, zh$\bar{o}$ng-ji-xu$\acute{e}$. 6. The other treatment is a sitz bath that prevent of urinary tract infection, and relieve of initial acute auresis by using of urethral catheterization.

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Comparative analysis of the magnetic and the transport properties of electron- and hole-doped manganite films

  • Kim, K.W.;Prokhorov, V.G.;Flis, V.S.;Park, J.S.;Eom, T.W.;Lee, Y.P.;Svetchnikov, V.L.
    • Proceedings of the Korean Vacuum Society Conference
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.226-226
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    • 2010
  • Microstructure, magnetic and transport properties of as-deposited electron-doped $La_{1-x}Ce_xMnO_3$ and hole-doped $La_{1-x}Ce_xMnO_3$ films prepared by pulse laser deposition, with x = 0.1 and 0.3, have been investigated. The microstructural analysis reveals that the $La_{1-x}Ce_xMnO_3$ films have a column-like microstructure and a strip-domain phase with a periodic spacing of about 3c, which were not found for the $La_{1-x}Ce_xMnO_3$ ones. At the same time, the experimental results manifest that there is no fundamental difference in the magnetic and the transport properties between electron- and hole-doped manganite films, except the appearance of ferromagnetic response in the low-doped $La_{0.9}Ce_{0.1}MnO_3$ film at temperatures above the Curie point. The observed magnetic behavior, typical for the Griffiths-like phase, for this film is explained by the percolation mechanism of the ferromagnetic transition and by the presence of strip-domain phase which stimulates the magnetic phase separation.

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Mossbauer Study of nano-sized (Li_{0.5x}Fe_{0.5x}Zn_{1-x})Fe_2O_4$ particles

  • J. C. Sur;Kim, T. S.;T. Y. Ha;Lee, J. K.;S. H. Gee;Y. K. Hong;Park, M. H.;D. W. Erickson;P. J. Lamb
    • Proceedings of the Korean Magnestics Society Conference
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    • 한국자기학회 2002년도 동계연구발표회 논문개요집
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    • pp.92-93
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    • 2002
  • The substituted lithium ferrites combine useful ferromagnetic properties with high Curie temperature ranging from 55$0^{\circ}C$ to 85$0^{\circ}C$, [1] high saturation magnetization, [2] and low microwave dielectric loss.[3] Saturation magnetization of (Z $n_{1-x}$ F $e_{x}$)A[L $i_{0.5x}$F $e_{ 2-0.5x}$]$_{B}$ $O_4$ increased with zinc concentration, followed by a decrease at x = 0.7.[4] This is attributed to a dilution of the A-site with zinc which initially causes an increase in saturation magnetization due to the dominance of the B-site. (omitted)d))d)d))

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Reel-to-reel Deposition of $Y_2O_3$ Buffer Layer on Ni-W Metal Substrates by the RF-sputtering (RF-스퍼터링법을 이용하여 Ni-W 금속기판에 연속공정으로 증착된 $Y_2O_3$ 완충층 특성 연구)

  • Chung, K.C.;Jeong, T.J.;Choi, G.C.;Kim, Y.K.;Wang, X.L.;Dou, S.X.
    • Progress in Superconductivity
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    • 제11권2호
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    • pp.100-105
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    • 2010
  • Reel-to-reel deposition of $Y_2O_3$ has been performed on Ni-5%W metal substrates using the RF-sputtering method. The epitaxial orientation of $Y_2O_3$ buffer layers to the base bi-axially textured substrate was well identified using ${\theta}-2{\theta}$, out-of-plane ($\omega$), and in-plane ($\phi$) scans in X-ray diffraction analysis. The optimization of $Y_2O_3$ seed layers in reel-to-reel fashion were investigated varying the deposition temperature, sputtering power, and pressure for its significant roles for the following buffer stacks and superconducting layers. $Y_2O_3$ were all grown epitaxially on bi-axially textured metal substrates at 380 watts and 5 mTorr in the temperature range of $600-740^{\circ}C$ with higher $Y_2O_3$ (400) intensities at ${\sim}710^{\circ}C$. It was found that the $\Delta\omega$ values were $1-2^{\circ}$ lower but the $\Delta\phi$ values were above $1^{\circ}$ higher than that of Ni-W substrates. As the sputtering power increased from 340 to 380 watts, $\Delta\omega$ and $\Delta\phi$ values showed decreased tendency. Even in the small window of deposition pressure of 3-7 mTorr, the $Y_2O_3$ (400) intensities increased and $\Delta\omega$ and $\Delta\phi$ values were reduced as sputtering pressure increased.

Reliability Enhancement of Hybrid Superconducting Fault Current Limiter adopting Power Electric Device (전력용 반도체 소자를 적용한 하이브리드 초전도 한류기 동작 신뢰도 향상)

  • Sim, J.;Park, K.B.;Lim, S.W.;Kim, H.R.;Lee, B.W.;Oh, I.S.;Hyun, O.B.
    • Progress in Superconductivity and Cryogenics
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    • 제9권3호
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    • pp.57-61
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    • 2007
  • The current limiting characteristics of hybrid SFCL with additional power electronic devices was investigated in order to improve operation reliabilities. The hybrid SFCL developed consists of a superconducting trigger (S/T) part, a fast switch (F/S) module and a current limiting (C/L) part. Although hybrid SFCL had shown a excellent current limiting characteristics, this device was rather vulnerable to the residual arc currents which could exist during fast switch operation. This undesirable arc should be extinguished as quickly as possible in order to implement perfect fault current commutation. So, in order to eliminate the residual arcs between fast switch contacts, the power electronic devices (IGBT or GTO) were connected in series between the S/T part and the interrupter of the F/S module. According to the fault tests conducting with an input voltage of $270\;V_{rms}$ and a fault current of $5\;kA_{rms}$, The power electronic devices could perfectly remove the arc generated between the contacts of the interrupter within 4 ms after the fault occurred. From the test analysis, it was confirmed that the hybrid SFCL could enhance the operation reliability by adopting additional power electronic devices.