• Title/Summary/Keyword: CHO

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A Study on the Operating Characteristics for the Grid Interconnected PV System with BESS (BESS를 적용한 계통연계형 PV시스템의 운전특성에 관한 연구)

  • Lee, Kang-Yeon;Jeong, Byeong-Ho;Cho, Geum-Bae;Baek, Hyung-Lae;Jung, Hae-Duck
    • Journal of the Korean Solar Energy Society
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    • v.26 no.2
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    • pp.69-77
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    • 2006
  • Photovoltaic is an attractive technology to remote power applications, because of its reliability, low maintenance, and zero fuel requirements. In this paper represents residential PV system based on BESS(battery energy storage system) for managing the electric power, a pattern of daily operation considering the load characteristics of the house, the generation characteristics of PV power, and utility power leveling. For apply to control algorithm, we consider the load on monthly power consumption trend and daily usage pattern. As for the control of the proposed system, to increase the conversion efficiency of the PV power, bidirectional converter is used for MPPT and SPWM inverter. An experimental system is implemented, and some experimental results are provided to demonstrate the effectiveness of the proposed system.

Pharmacognostical Studies on a Folk Medicine "SinKyungCho" (민간약 신경초의 생약학적 연구)

  • Bae, Ji-Yeong;Goo, Young-Min;Park, Jong Hee;Ahn, Mi-Jeong
    • Korean Journal of Pharmacognosy
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    • v.44 no.4
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    • pp.326-331
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    • 2013
  • A Korean folk medicine, "SinKyungCho" has been used to cure common cold and rheumatis. While this crude drug has similar morphological feature to that of Rubia species, the botanical origin has never been studied pharmacognostically. Therefore, in order to clarify the botanical origin of "SinKyungCho", the morphological and anatomical characteristics of Rubia species growing in Korea, i.e. R. akane, R. chinensis var. glabrescens, R. cordifolia var. pratensis, R. cordifolia var. sylvatica were studied. Especially, differing from the other three species, R. cordifolia var. pratensis has 2-4 cork cell layers under the endodermal cell layer. R. cordifolia var. sylvatica showed the largest number of parenchyma cell layers in cortex by 8-17. While the average ratio of stele to root transverse section is over 45% for R. akane and R. cordifolia var. pratensis, the ratio is under 45% for R. chinensis var. glabrescens and R. cordifolia var. sylvatica. According to these morphological criteria, the folk medicine "SinKyungCho" from Korean traditional market was proved to be the underground part of R. akane.

Assessment of Malignancy in Brain Tumors by 3T MR Spectroscopy

  • 최보영;전신수;이재문;정성택;안창범;오창현;김선일;이형구;서태석
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2003.09a
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    • pp.76-76
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    • 2003
  • Purpose: To assess clinical proton MR spectroscopy (MRS) as a noninvasive method for evaluating tumor malignancy at 3T high field system. Methods: Using 3T MRI/MRS system, localized water-suppressed single-voxel technique in patients with brain tumors was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantificated as a relative ratio. Results: The variation of metabolites measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67$\pm$018 and 1.16:1:0.15, respectively. NAA/Cr ratio of all tumor tissues was significantly lower than that of the normal tissues (P=0.005). Cho/Cr ratio of high-grade gliomas was significantly higher than that of low-grade gliomas (P= 0.001), Except 4 menigiomas, lactate signal was observed in all tumor cases. Conclusions: The present study demonstrated that the neuronal degradation or loss was observed in all tumor tissues. Higher grade of brain tumors was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. This results suggest that clinical proton MR spectroscopy could be useful to predict tumor malignancy. Acknowledgement: This study was supported by a grant of the Mid and Long Term Nuclear R/D Plan Program, Ministry of Science and Technology, Republic of Korea.

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A Study on the Development of Hypotensive Agent (I) -Hypotensive Action and Mechanism of Junci Herba in the Rabbit- (고혈압(高血壓) 치료제(治療劑)의 개발(開發)에 관(關)한 연구(硏究)(I) -등심초(燈心草)의 혈압강하(血壓降下) 작용(作用) 및 기전(機轉)-)

  • Moon, Young-Hee;Ko, Suk-Tai;Lee, Jin-Hwan;Kim, Sung-Wun;Ha, Chun-Ja
    • Korean Journal of Pharmacognosy
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    • v.6 no.4
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    • pp.211-217
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    • 1975
  • The blood pressure response to Junci Herba water and methanol extracts in rabbit and $LD_{50}$ to Junci Herba water extract in mouse were investigated in order to develop a hypotensive agent from natural resources. $LD_{50}$ of Junci Herba water extract (WE) was 600 mg/kg in mouse, when WE was injected intraperitonealy. Junci Herba water and methanol extract, when injected into the vein of rabbit, produced a fall of blood pressure. Hypotensive effect of WE was suppressed by atropine and potentiated by phentolamine, while not affected by avil, propranolol, and phenoxybenzamine. Intravenous injection of chlorisondamine weakened the hypotensive effect of WE, and WE produced hypertensive effect in this rabbit. Intravenous injection of bretylium did not affect the hypotensive effect of WE, but WE produced hypertensive effect in this rabbit. In the rabbit treated with chlorisondamine, hypertensive effect of WE was suppressed by methysergide or bretylium, but not affected by atropine or phenoxybenzamine.

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