• Title/Summary/Keyword: $T_{50},\

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Effect of SRA on Hysteresis and Eddy Current Components of Iron Loss in Non-Oriented Steels (무방향성 전기 강판 철손의 자기 이력 손실과 와전류 손실에 미치는 SRA의 영향)

  • 송창열;강이국;신용덕
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.208-211
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    • 1995
  • This proper focuses on results of relative permeability(${\mu}$$\sub$r/), core loss(W) and magnetic induction [B] measurements on some of the most commonly used core materials(PN-18, 20, 30, 60, Pohang Iron '||'&'||' Steel Co., Ltd.) In case of Stress Relief Annealing(SRA). Results of magnetic induction[B] showed weak variations but core lass reduced strongly after SRA Core loss reduced from 3.071 ∼7.819(W/kg) and 11.377~3.988[W/kg] to 2.88~5.492[W/kg] and 1.213~2.134[W/kg] at 1.5[T] 50 Hz and 1.0 [T] 50Hz respectively after SRA. This SRA process leads to significant changes In magnetic properties and core loss of non-oriented silicon steel sheet.

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Microstructure and Superconducting Properties of Ag-$Bi_{1.84}Pb_{0.34}Sr_{1.91}Ca_{2.03}Cu_{3.06}O_{10+{\delta}}$ Composites (Ag-$Bi_{1.84}Pb_{0.34}Sr_{1.91}Ca_{2.03}Cu_{3.06}O_{10+{\delta}}$ 복합체의 미세구조와 초전도특성)

  • 이민수
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.6
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    • pp.249-256
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    • 2003
  • Samples with the nominal composition, Ag-$Bi_{1.84}Pb_{0.34}Sr_{1.91}Ca_{2.03}Cu_{3.06}O_{10+{\delta}}$ high $T_{c}$ superconductors containing Ag as an additive were fabricated by a solid-state reaction method. Samples with Ag of 10 wt%, 30 wt%, and 50 wt% each were sintered at $860^{\circ}C$~$870^{\circ}C$ for 24 hours. The structural characteristics, the microstructures and the critical temperature with respect to the each samples were investigated by XRD, four-prove methode, SEM and EDS respectively. The $T_{c}\;^{zero}$ of the sample with the 50 wt% Ag additive at the surface showed 94 K.

Development of TPA-induced Ornithine Decarboxylase (ODC) Inhibitors from Plants as Cancer Chemopreventive Agents

  • Kim, Soo-Jeong;Lee, Ik-Soo;Chang, Il-Moo;Mar, Woong-Chon
    • Natural Product Sciences
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    • v.2 no.2
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    • pp.123-129
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    • 1996
  • Chemical carcinogenesis is associated with the increase of intracellular polyamine levels, and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse epidermal ODC activity are essential to skin tumor promotion by TPA. Therefore, for the discovery of new cancer chemopreventive agents, we have evaluated about 73 kinds of natural products to study inhibitory effects against ODC activity induced by TPA in T24 cell culture system. The total methanol extracts of plants fractionated into three layers (hexane, ethyl acetate and water layer) were tested and the hexane fraction of Angelica gigas $(root\;bark,\;IC_{50}:\;7.4\;{\mu}g/ml)$ and the ethyl acetate fraction of Corydalis ternata $(root,\;IC_{50}:\;7.5\;{\mu}g/ml)$ were the most effective on the inhibition of TPA-induced ODC activity, These active fractions are under investigation with further sequential fractionation using column chromatography.

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SEMIGROUP PRESENTATIONS FOR CONGRUENCES ON GROUPS

  • Ayik, Gonca;Caliskan, Basri
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.2
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    • pp.445-449
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    • 2013
  • We consider a congruence ${\rho}$ on a group G as a subsemigroup of the direct product $G{\times}G$. It is well known that a relation ${\rho}$ on G is a congruence if and only if there exists a normal subgroup N of G such that ${\rho}=\{(s,\;t):st^{-1}{\in}N\}$. In this paper we prove that if G is a finitely presented group, and if N is a normal subgroup of G with finite index, then the congruence ${\rho}=\{(s,\;t):st^{-1}{\in}N\}$ on G is finitely presented.

Glioblastoma Mimicking Herpes Simplex Encephalitis

  • Nam, Tai-Seung;Choi, Kang-Ho;Kim, Myeong-Kyu;Cho, Ki-Hyun
    • Journal of Korean Neurosurgical Society
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    • v.50 no.2
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    • pp.119-122
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    • 2011
  • We report a case of 70-year-old man with glioblastoma presenting as acute encephalitic illness. The patient exhibited sudden onset of cognitive impairment and headache for 2 days. Initial brain MRI showed left temporal lobe hyperintensity, and cerebrospinal fluid cytology revealed a mild pleocytosis. The patient had initially improved after medical treatment with a presumptive diagnosis of herpes simplex encephalitis (HSE). After 8 months, the patient complained of recurrent seizures. A follow-up brain MRI revealed marked increases in size and surrounding perilesional edema in the left temporal lesion on T2-weighted images and a new contrast-enhancing lesion on gadolinium-enhanced T1-weighted images. Stereotactic brain biopsy revealed a glioblastoma. The atypical encephalitic presentation of glioblastoma should be considered if definitive evidence for the diagnosis of HSE cannot be obtained.

A Clinical study on mutation of personality in Low back pain patients (요통환자의 인성변화에 대한 임상적 고찰)

  • Kim, Gyu-Yong
    • Journal of Korean Physical Therapy Science
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    • v.6 no.4
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    • pp.179-185
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    • 1999
  • We know that social psychologic factors important to make a decision on characteristic of back pain and prognosis. These facters have difficult to diagnosis of back pain and being protract the treatment session and which bring about a social problem caused the impairment compensation. Clinically, twenty low back pain patients, 8 organic pain group and 12 functional pain group have completed the MMPI(Minnesota Multiphasic Personality Inventory) and the results were as follows: l)Mean MMPI T-score of Hypochondriasis was 56.60(12.39, that of Depression was 57.95(7.71, and that of Hysteria was 57.50(7.15. and those of other scales were within normal range near to 50. 2)there was no significant difference between male and female groups on MMPI scales 3)The MMPI T-score of organic group was significantly higher than that of functional group on Hypochondriasis and Hysteria scale.

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Mechanism of Soil Remediation in Contaminated Area Using Vertical Drains (연직배수재(VDs)에 의한 오염지반정화 메커니즘 연구)

  • Lee Haeng Woo;Chang Pyoung Wuck;Kang Byung Yoon;Kim Hyun Tae
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.5
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    • pp.63-71
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    • 2005
  • In-situ soil remediation mechanism through the vertical drains (VDs) is analyzed with numerical model as the error and complementary error function. Results from in-situ test and analysis indicate that the contaminant concentration ratio as initial one ( C/$C_0$) increases as the radius ratio ( r/R) increases from the injection well, and also increases as the depth ratio ( z/ H) increases from the top of contaminated area. The elapse time needed to attain $50\%$ and $90\%$ clean up level ($ t_{50},\;t_{90}$) increases as the radius ratio ( r/R) and the depth ratio ( z/ H) increase. As above results, the procedure of soil flushing in contaminated area using vertical drains makes progress from the top of injection well to the bottom of extraction well.

Oxidation Behavior of UO$_2$in Air at 300~55$0^{\circ}C$

  • Kang, Kweon-Ho;Hwang, Suk-Youl;Kim, Kil-Jeong
    • Journal of Energy Engineering
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    • v.6 no.2
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    • pp.198-202
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    • 1997
  • The oxidation behavior of UO$_2$pellets was studied using a thermogravimetric analyzer and an XRD in the temperature range of 300 to 550$^{\circ}C$ in air. From XRD studies it is found that UO$_2$is converted to U$_3$O$\_$8/ and the weight gains of UO$_2$specimen are characterized by S-shape curves. After complete oxidation the specimens broke into fine powder and the average weight gain was about 3.93 wt%. The activation energy of 50% conversion of UO$_2$to U$_3$O$\_$8/ is 81.6 kJ/mol and the oxidation rate per unit time was found to be as follows dw/dt=6.54${\times}$10$\^$6/ e (equation omitted), wt%/h : at 50% conversion of UO$_2$into U$_3$O$\_$8/ where w, t and T were wt% gain, conversion time and temperature, respectively.

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Driving Forces for γ→ε Martensitic Transformation of Fe-Mn Alloys (Fe-Mn 합금의 γ→ε 마르텐사이트변태에 필요한 구동력)

  • Lee, Young-Kook;Choi, Chong-Sool
    • Journal of the Korean Society for Heat Treatment
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    • v.9 no.4
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    • pp.243-251
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    • 1996
  • Dilatometric experiment and thermodynamic calculation have been performed to determine $M_s$, $A_s$ and driving forces for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation of Fe-Mn alloys. The transformation temperatures($M_s$, $A_s$, $T_o) were decreased with increasing manganese content and were newly formulated as a function of manganese content. Driving force for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation was increased from -75J/mole to -105J/mole with increasing manganese content from 15wt.% to 25wt.%. Transformation temperature hysteresis($A_s-M_s$) was also increased from 50K to 80K with increasing mangenese content from 15wt.% to 25wt.%. The small driving force(-75J/mole~-105J/mole) and small ${\Delta}T$(50K~80K) for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation indicated that Fe-Mn alloys behave like thermoelastic martensitic alloys : We would like to call them semi-thermoelastic martensitic alloys.

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Effect of Glucosinolates of Taramira (Eruca Sativa) Oilcake on Nutrient Utilization and Growth of Crossbred Calves

  • Das, Srinibas;Tyagi, Amrish Kumar;Singhal, K.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.6
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    • pp.813-817
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    • 2003
  • Taramira (Eruca sativa) cake, an unconventional oil cake, replaced 25 and 50 per cent crude protein of mustard cake in the ration of crossbred calves in an experiment of 90 days duration. Total glucosinolate content of the three concentrate mixture was almost similar (18.19, 17.95 and $17.95{\mu}mol/g$ dry matter), however, glucouracin was the major glucosinolate of experimental diets. Similar dry matter Intake, nutrient digestibility (except those of fibre fractions) and nitrogen balances as well as similar serum $T_3$ and $T_4$ levels and growth rate in all the groups indicated that taramira cake can replace 50 per cent crude protein of mustard cake in the diet of crossbred calves.