• Title/Summary/Keyword: C1-2 instability

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Premenstrual Discomforts and Coping in University Students (여대생의 월경전 불편감과 대처에 관한 연구)

  • Ahn, Hye-Young;Hyun, Hye-Jin;Kim, Hae-Won
    • Research in Community and Public Health Nursing
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    • v.16 no.3
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    • pp.289-299
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    • 2005
  • Purpose: This study was carried out to identify premenstrual discomforts and coping patterns and their effects. Method: The participants of this study were 297 female university students in C area. The Menstrual Discomfort Questionaire (MDQ) and coping method lists were used as measurement tools. Results: There were significant differences premenstrual discomforts according to age (F=5.76, p=.003) and according to health condition (F=3.43, p=.034). The mean scores of the sub-categorical factors of premenstrual discomfort were 2.35 points for pain, 2.29 for instability and 2.25 for water retention. The worst symptoms among the subcategories of premenstrual discomfort were as follows: backache (M=2.68) in the pain subcategory, irritability (M=2.53) in the instability subcategory and swelling(M=2.40) in the water retention subcategory. Their common coping patterns were 'coping according to menstrual period', 'active behavioral coping' and 'evasional coping'. Frequently used coping methods were 'taking a rest and sleep (99.3%)' and 'taking a warm shower (86.2%)'. Effective coping methods were 'taking a rest and sleep (89.5%)' and 'taking a warm shower (87.1%)'. Conclusion: Most participants have their own coping pattern. Some methods were very effective to PMS but some were not effective to PMS. To manage PMS, effective coping methods should be encouraged for female university students. To keep up with effective coping, education and counseling should be continued. It is considered necessary to make the same research with a larger number of samples and more specified assessment.

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Optimum forming design of A350 LF2 alloy using the deformation processing map (변형 공정지도를 활용한 A350 LF2 합금의 최적성형 조건설계에 대한 연구)

  • Jung, E.J.;Yeom, J.T.;Kim, J.H.;Lee, D.G.;Pak, N.K.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.168-171
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    • 2006
  • Hot deformation behavior of A350 LF2 alloy was characterized by compression tests in the temperature range of 800-$1250^{\circ}C$ and the strain rate range of $0.001-10s^{-1}$. The microstructural evolution during hot compression was investigated and deformation mechanisms were analyzed by constructing processing map. Processing maps were generated using the dynamic material model (DMM). The combination of dynamic material model and Ziegler's instability criterion was applied to predict an optimum condition and unstable regions for hot forming.

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A Study on the transesterification reaction between diethanolamine and dimethylphthalate (디에탄올아민과 디메틸프탈레이트와의 에스테르 교환반응에 관한 연구)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.2 no.2
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    • pp.25-30
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    • 1985
  • The transesterification reaction between diethanolamine and dimethylphthalate was kinetically investigated in the presence of various metal acetate catalysts at $130^{\circ}C$. The reaction was followed by the measurement of distilled methanol from the reaction vessel. The transesterification was found to obey first-order kinetics with respect to the concentration of diethanolamine and dimethylphthalate and catalyst, respectively. The reactivities has highest value where the electronegativity and instability constand (Kij) values for the metal acetate catalysts are about 1.6.

A Study on the Transesterification Reaction between Ethanolamine and Methyl-methacrylate (에탄올아민과 메틸메타크릴레이트의 에스테르 교환반응에 관한 연구)

  • Park, Keun-Ho;Sohn, Byoung-Chung;Ryu, Chul-Mo
    • Journal of the Korean Applied Science and Technology
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    • v.2 no.2
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    • pp.31-38
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    • 1985
  • The transesterification reaction between ethanolamine and methyl-methacrylate was kinetically investigated in the presence of various metal acetate catalysts at $110^{\circ}C$. The transesterification was found to obey first-order kinetice with respect to the concentration of ethanolamine and methyl-methacrylate, respectively. By the Arrhenius plot, the activation energy has been calculated as 11.9 Kcal with lead acetate catalyst, 14.7 Kcal without catalyst. The reactivities has highest value where the electronegativity and instability constant (Kij) values for the metal acetate catalysts are about 1.6.

Characteristics of Sulfide Treated GaAs MISFETs with Photo-CVD Grown $P_3$$N_5$ Gate Insulators (유화처리와 광CVD법 질화인막을 이용한 GaAs MISFET 특성)

  • 최기환;조규성;정윤하
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.9
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    • pp.72-77
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    • 1994
  • GaAs MISFETs, with photo-CVD grown P$_{3}$N$_{5}$ gate insulator and sulfide treatment, have been fabricated and showed the instability of drain current reduced less than 22 percent for the period of 1.0s~1.0${\times}10^{4}s$. The effective electron mobility and extrinsic transconductance of the device are about 1300cm$^{2}$/V.sec and 1.33mS at room temperature. The C-V characteristics of GaAs MIS Diode and AES analysis are also discussed with respect to effect of sulfide treatment conditions.

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Local TIGRESS Simulations of Star Formation in Spiral Galaxies

  • Kim, Woong-Tae;Kim, Chang-Goo;Ostriker, Eve C.
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.51.1-51.1
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    • 2021
  • Spiral arms greatly affect gas flows and star formation in disk galaxies. We use local 3D simulations of vertically-stratified, self-gravitating, gaseous disks under a stellar spiral potential to study the effects of spiral arms on galactic star formation as well as formation of gaseous spurs/feathers. We adopt the TIGRESS framework to handle radiative heating and cooling, star formation, and ensuing supernova (SN) feedback. We find that more than 90% of star formation takes place inside spiral arms. The global star formation rate (SFR) in models with spiral arms is enhanced by less than a factor of 2 compared to the no-arm counterpart. This supports the picture that spiral arms do not trigger star formation but rather redistribute star-forming regions. Correlated SN feedback produces interarm feathers in both magnetized and unmagnetized models. These feathers live short, have parallel magnetic fields along their length, and are bounded by SN feedback in the lateral direction, in contrast to instability-induced feathers formed in our previous isothermal simulations.

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What are the Differences in Outcome among Various Fusion Methods of the Lumbar Spine?

  • Kang, Suk-Hyung;Kim, Young-Baeg;Park, Seung-Won;Hong, Hyun-Jong;Min, Byung-Kook
    • Journal of Korean Neurosurgical Society
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    • v.37 no.1
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    • pp.39-43
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    • 2005
  • Objective: For Posterior lumbar interbody fusion(PLIF) various cages or iliac bone dowels are used with or without pedicle screw fixation(PSF). To evaluate and compare the clinical and radiological results of different fusion methods, we intend to verify the effect of added PSF on PLIF, the effect of bone cages and several factors which are thought to be related with the postoperative prognosis. Methods: One hundred and ninety seven patients with lumbar spinal stenosis and instability or spondylolisthesis underwent various fusion operations from May 1993 to May 2003. The patients were divided into five groups, group A (PLIF with autologous bone dowels, N=24), group B (PLIF with bone cages, N=13), group C (PLIF with bone dowels and PSF, N=37), group D (PLIF with bone cages and PSF, N=30) and group E (PSF with intertransverse bone graft, N=93) for comparison and analyzed for the outcome and fusion rate. Results: Outcome was not significantly different among the five groups. In intervertebral height (IVH) changes between pre- and post-operation, Group B ($2.42{\pm}2.20mm$) was better than Group A ($-1.33{\pm}2.05mm$). But in the Group C, D and E, the IVH changes were not different statistically. Fusion rate of group C, D was higher than that of Group A and B. But the intervertebral height(IVH) increased significantly in group B($2.42{\pm}2.20mm$). Fusion rate of group C and D were higher than that of group A and D. Conclusion: Intervertebral cages are superior to autologous iliac bone dowels for maintaining intervertebral height in PLIF. The additional pedicle screw fixation seems to stabilize the graft and improve fusion rates.

Study on Physicochemical Properties of Pesticide. (I) Water Solubility, Hydrolysis, Vapor Pressure, and n-Octanol/water Partition Coefficient of Captafol (농약의 물리화학적 특성연구 (I) Captafol의 수용성, 가수분해, 증기압, 옥탄올/물 분배계수)

  • Kim, Jeong-Han;Lee, Sung-Kyu;Kim, Yong-Hwa;Kim, Kyun
    • Applied Biological Chemistry
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    • v.40 no.1
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    • pp.71-75
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    • 1997
  • Important physicochemical properties of captafol [N-(1,1,2,2-tetrachloro-ethylthio)cyclohex-4-ene-1,2-dicarboximide], water solubility, vapor pressure, hydrolysis and octanol/water partition coefficient(Kow) were measured based on the standard EPA and OECD methods. Water solubility of the chemical was 2.24 ppm at $25^{\circ}C$. Half-life by hydrolysis at $25^{\circ}C$ in the buffer solution of pH 3.0, pH 7.0, and pH 8.0 was 77.8 hr, 6.54 hr and 0.72 hr, respectively, demonstrating instability in alkaline solution. The half-life in acid condition was not significantly different by temperature change, however, that in neutral or alkaline solution became shorter at $40^{\circ}C$. Hydrolysis study with a reference compound, diazinon, proved that the experimental method of the present study is reliable. Vapor pressure of captafol, $8.27{\times}10^{-9}$ torr at $20^{\circ}C$, was calculated from the equation, log P=6.94-(4401.6/T) plotted on the experiment results under different temperature conditions, 40, 50, and $60^{\circ}C$. pressure of captafol, the contamination of captafol would not happen easily in environment by vaporization. High Kow value of 1,523 was observed and this might result in bioconcentration through food chain when captafol was exposed. However, affecting human health through aquatic bioaccumulation is not likely to occur due to its rapid hydrolysis in the environment.

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Forming Gas Post Metallization Annealing of Recessed AlGaN/GaN-on-Si MOSHFET

  • Lee, Jung-Yeon;Park, Bong-Ryeol;Lee, Jae-Gil;Lim, Jongtae;Cha, Ho-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.1
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    • pp.16-21
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    • 2015
  • In this study, the effects of forming gas post metallization annealing (PMA) on recessed AlGaN/GaN-on-Si MOSHFET were investigated. The device employed an ICPCVD $SiO_2$ film as a gate oxide layer on which a Ni/Au gate was evaporated. The PMA process was carried out at $350^{\circ}C$ in forming gas ambient. It was found that the device instability was improved with significant reduction in interface trap density by forming gas PMA.