• Title/Summary/Keyword: I-V monitoring

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Drug Interaction Between Phenytoin and Diltiazem in Rabbit (딜티아젬과 페니토인과의 약물상호작용)

  • Choi, Jun-Shik;Chang, Il-Hyo
    • Journal of Pharmaceutical Investigation
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    • v.23 no.1
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    • pp.27-32
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    • 1993
  • Pharmacokinetic drug interaction between phenytoin and diltiazem was investigated following i.v. administration concomitantly to rabbits. Diltiazem was coadministered at doses of 1, 2 and 3 mg/kg, respectively, with phenytoin (5 mg/kg) to rabbits. Plasma concentration and AUC of phenytoin were increased significantly, but volume of distribution and total body clearance were decreased significantly (p<0.05) at doses of 2 mg and 3 mg/kg of diltiazem. From the results of this experiment, it is desirable that dosage regimen of phenytoin should be adjusted and that therapeutic drug monitoring should be practiced for reduction of side or toxic effect when phenytoin should be administered with diltiazem in clinical practice.

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Estimating the Loss Ratio of Solar Photovoltaic Electricity Generation through Stochastic Analysis

  • Hong, Taehoon;Koo, Choongwan;Lee, Minhyun
    • Journal of Construction Engineering and Project Management
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    • v.3 no.3
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    • pp.23-34
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    • 2013
  • As climate change and environmental pollution become one of the biggest global issues today, new renewable energy, especially solar photovoltaic (PV) system, is getting great attention as a sustainable energy source. However, initial investment cost of PV system is considerable, and thus, it is crucial to predict electricity generation accurately before installation of the system. This study analyzes the loss ratio of solar photovoltaic electricity generation from the actual PV system monitoring data to predict electricity generation more accurately in advance. This study is carried out with the following five steps: (i) Data collection of actual electricity generation from PV system and the related information; (ii) Calculation of simulation-based electricity generation; (iii) Comparative analysis between actual electricity generation and simulation-based electricity generation based on the seasonality; (iv) Stochastic approach by defining probability distribution of loss ratio between actual electricity generation and simulation-based electricity generation ; and (v) Case study by conducting Monte-Carlo Simulation (MCS) based on the probability distribution function of loss ratio. The results of this study could be used (i) to estimate electricity generation from PV system more accurately before installation of the system, (ii) to establish the optimal maintenance strategy for the different application fields and the different season, and (iii) to conduct feasibility study on investment at the level of life cycle.

Realtime Monitoring system of Residential Photovoltaic system (태양광-풍력 복합발전시스템의 출력제어 특성에 관한 연구)

  • Lee J.I.;Suh J.S.;Yoon P.H.;Cha I.S.
    • Proceedings of the KIPE Conference
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    • 2003.07b
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    • pp.933-937
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    • 2003
  • The development of the solar and the wind power energy are necessary since the future alternative energies that have no pollution and no limitation are restricted. Currently power generation system of MW scale has been developed, but it still has a few faults with the weather condition. In order to solve these existing problems, combined generation system of photovoltaic(400w) and wind power generation system(400w) was suggested. It combines wind power and solar energy to have the supporting effect from each other However, since even combined generation system cannot always generate stable output with ever-changing weather condition, power compensation device that uses elastic energy of spiral spring to combined generation system was also added for the present study. In an experiment, when output of system gets lower than 12V(charging voltage), power was continuously supplied to load through the inverter by charging energy obtained from generating rotary energy of spiral spring operates in small scale generator

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Reliablity of Distributed Feedback Laser Diodes for High-speed Optical Communication Systems (고속 광통신 시스템용 비대칭 분포귀환형 레이져 다이오드의 신뢰성에 관한 연구)

  • Jeon, Su-Chang;Joo, Han-Sung;Yun, Il-Gu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05a
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    • pp.96-99
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    • 2005
  • As the demand of internet networks using backbone communication systems recently increased, the researches on the high-speed wideband optical communication systems are required. For high-speed optical communication systems, asymmetric sampled grating distributed feedback laser diodes (DFB-LDs) are developed and the reliability of DFB-LDs is examined. The reliability of DFB-LDs is performed by monitoring I-V and L-I characteristics and two degradation phenomena related to the electrical characteristics of LDs are observed during the life tests. The first degradation phenomenon by increasing the reverse current is considered as a formation of leakage current path enough to prevent lasing operation in lateral blocking layer near active region of lasers. The second degradation phenomenon by decreasing the forward current is considered as activation of non-radiative Auger recombination process by thermal energy and the second degradation phenomenon is recovered after the off-test period at room temperature Eventually, evaluating the reliability of DFB LDs can allow us to improved the manufacturability in high-volume manufacturing.

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ESTIMATING THE LOSS RATIO OF SOLAR PHOTOVOLTAIC ELECTRICITY GENERATION THROUGH STOCHASTIC ANALYSIS

  • Taehoon Hong;Choongwan Koo;Minhyun Lee
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.375-385
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    • 2013
  • As climate change and environmental pollution become one of the biggest global issues today, new renewable energy, especially solar photovoltaic (PV) system, is getting great attention as a sustainable energy source. However, initial investment cost of PV system is considerable, and thus, it is crucial to predict electricity generation accurately before installation of the system. This study analyzes the loss ratio of solar photovoltaic electricity generation from the actual PV system monitoring data to predict electricity generation more accurately in advance. This study is carried out with the following five steps: (i) Data collection of actual electricity generation from PV system and the related information; (ii) Calculation of simulation-based electricity generation; (iii) Comparative analysis between actual electricity generation and simulation-based electricity generation based on the seasonality; (iv) Stochastic approach by defining probability distribution of loss ratio between actual electricity generation and simulation-based electricity generation ; and (v) Case study by conducting Monte-Carlo Simulation (MCS) based on the probability distribution function of loss ratio. The results of this study could be used (i) to estimate electricity generation from PV system more accurately before installation of the system, (ii) to establish the optimal maintenance strategy for the different application fields and the different season, and (iii) to conduct feasibility study on investment at the level of life cycle.

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Investigating the Impact of Best Management Practices on Nonpoint Source Pollution from Agricultural Lands

  • ;Saied Mostaghimi
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.32 no.E
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    • pp.1-19
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    • 1990
  • Abstract Over the last several decades, crop production in the United States increased largely due to the extensive use of animal waste and fertilizers as plant nutrient supplements, and pesticides for crops pests and weed control. Without the application of animal waste best management, the use of animal waste can result in nonpoint source pollution from agricultural land area. In order to increase nutrient levels and decrease contamination from agricultural lands, nonpoint source pollution is responsible for water quality degradation. Nonpoint source pollutants such as animal waste, ferilizers, and pesticides are transported primarily through runoff from agricultural areas. Nutrients, primarily nitrogen and phosphorus, can be a major water quality problem because they cause eutrophic algae growth. In 1985, it was presented that Watershed/Water Quality Monitoring for Evaluation BMP Effectiveness was implemented for Nomini Creek Watershed, located in Westmoreland County, Virginia. The watershed is predominantly agricultural and has an aerial extent of 1505 ha of land, with 43% under cropland, 54% under woodland, and 3% as homestead and roads. Rainfall data was collected at the watershed from raingages located at sites PNI through PN 7. Streams at stations QN I and QN2 were being measured with V-notch weirs. Water levels at the stream was measured using an FW-l Belfort (Friez FWl). The water quality monitoring system was designed to provide comprehensive assessment of the quality of storm runoff and baseflow as influenced by changes in landuse, agronomic, and cultural practices ill the watershed. As this study was concerned with the Nomini Creek Watershed, the separation of storm runoff and baseflow measured at QNI and QN2 was given by the master depletion curve method, and the loadings of baseflow and storm runoff for TN (Total Nitrogen) and TP (Total Phosphorus) were analyzed from 1987 through 1989. The results were studied for the best management practices to reduce contamination and loss of nutrients, (e.g., total nitrogen and total phosphorus) by nonpoint source pollution from agricultural lands.

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Monitoring Ovarian Function by Solid- Phase Chemiluminescence Immunoassay

  • Kim, J.B.;Ku, P.S.
    • Clinical and Experimental Reproductive Medicine
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    • v.9 no.1_2
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    • pp.43-53
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    • 1982
  • 여성의 난소기능은 뇨중 Oestrone-3-glucuronide를 간편한 solid-phase 의 화학발광성 면역학적 측정법 (Chemiluminescence Imrnunoassay(CIA) 에 의하여 그 기능이 탐지될 수 있다. Oestrone-3-g1ucuronyl-6-bovine serum albumine에 대한 antiserum의 IgG fraction은 polystyrene 실험관벽에 흡착시켰으며, 항원으로서는 est r one-3- gl ucuronyI-6-aminoethyl-ethyl-isoluminol 을 항원 (antigen) 에 labeI 시킨 것이다. 시험 대상물인 뇨는 매일아침뇨(early morning urine) 을 희석 (1:1000 V/V)한 후 100mcl 를 취하여 이를 각기 이중분석액으로 택하였다. 시험관 내에서 결합반응 (1 hour at $4^{\circ}C)이 일어난 후에는 시험관내의 액체를 전부 흡입 폐기시켰으며, 항체반응이 일어난 후 ( antibody-bound fraction )에는 완충액 (400mcl)으로 한번 세척시켰다. 그후 염화수산화물(2N , 200mcl)을 가지고 $22^{\circ}C$에 60 분간 방치 혼합케 한 후 효소(microperoxidase) 와 과산화수소를 가하면서 산화작용에서 발생되는 발광양을 10초동안 측정하여 그 결과를 분석하였다. 위에 기술한 분석방법을 평가하면 다음과 같은 결론을 얻었다. Calibration curve sensitivity$3.12{\pm}0.75$ PG/tube ($mean{\pm}SD$)였고, lntra-assay precision(CV%) 9.52 (20 replicates;$38.4{\pm}3.66$nmol/1) 와 8.81 (15 replicates; $102.4{\pm}8.82$nmol/1)였다. Inter-assay precision(CV%) 은 11.9 (mean of 4 pools-7.03, 23.16, 52.11 과 117.53 nmol/1)로 2개월 동안에 걸쳐 시행되었고, 평균 비이어스(mean bias)는 -0.78 로 28에서 448 nmol 범위로서 매일아침 "뇨"의 차이분(different aliquots)은 좋은 결과를 얻었다. 건강한 여성으로부터 채취된 뇨중 Oestrone-3-glucuronide 의 농도(nmol/1)를 보면 월경주기의 여포기와 배난기 및 황체기에 있어서 각기 $40.2{\pm}9.9$ , $102.3{\pm}39.4$$84.3{\pm}13.3$nmol/1였다. 이와같은 결과는 동일한 검사뇨를 방사면역학적 방법(RIA)으로 측정 (6 menstrual cycle)한 결과와 유사한 측정치를 얻으므로서 간편하고 진보된 좋은 방법중의 하나라고 사료되는바이다.

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Effects of Fluvastatin on the Pharmacokinetics of Repaglinide: Possible Role of CYP3A4 and P-glycoprotein Inhibition by Fluvastatin

  • Lee, Chong-Ki;Choi, Jun-Shik;Bang, Joon Seok
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.3
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    • pp.245-251
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    • 2013
  • The purpose of this study was to investigate the effects of fluvastatin on the pharmacokinetics of repaglinide in rats. The effect of fluvastatin on P-glycoprotein and CYP3A4 activity was evaluated. The pharmacokinetic parameters and blood glucose concentrations were also determined after oral and intravenous administration of repaglinide to rats in the presence and absence of fluvastatin. Fluvastatin inhibited CYP3A4 activity in a concentration-dependent manner with a 50% inhibition concentration($IC_{50}$) of 4.1 ${\mu}M$ and P-gp activity. Compared to the oral control group, fluvastatin significantly increased the AUC and the peak plasma level of repaglinide by 45.9% and 22.7%, respectively. Fluvastatin significantly decreased the total body clearance (TBC) of repaglinide compared to the control. Fluvastatin also significantly increased the absolute bioavailability (BA) of repaglinide by 46.1% compared to the control group. Moreover, the relative BA of repaglinide was 1.14- to 1.46-fold greater than that of the control. Compared to the i.v. control, fluvastatin significantly increased the $AUC_{0-{\infty}}$ of i.v. administered repaglinide. The blood glucose concentrations showed significant differences compared to the oral controls. Fluvastatin enhanced the oral BA of repaglinide, which may be mainly attributable to the inhibition of the CYP3A4-mediated metabolism of repaglinide in the small intestine and/or liver, to the inhibition of the P-gp efflux transporter in the small intestine and/or to the reduction of TBC of repaglinide by fluvastatin. The study has raised the awareness of potential interactions during concomitant use of repaglinide with fluvastatin. Therefore, the concurrent use of repaglinide and fluvastatin may require close monitoring for potential drug interactions.

Radiative transfer analysis for Amon-Ra instrument

  • Seong, Se-Hyun;Ryu, Dong-Ok;Lee, Jae-Min;Hong, Jin-Suk;Kim, Seong-Hui;Yoon, Jee-Yeon;Park, Won-Hyun;Lee, Han-Shin;Park, Jong-Soo;Yu, Ji-Woong;Kim, Sug-Whan
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.28.4-29
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    • 2009
  • The 'Amon-Ra' instrument of the proposed 'EARTHSHINE' satellite is a dual (i.e. imaging and energy) channel instrument for monitoring the total solar irradiance (TSI) and the Earth's irradiance at around the L1 halo orbit. Earlier studies for this instrument include, but not limited to, design and construction of breadboard Amon-Ra imaging channel, stray light suppression and system performance computation using Integrated Ray Tracing (IRT) technique. The Amon-Ra instrument is required to produce 0.3% in uncertainty for both Sunlight and Earthlight measurement. In this study, we report accurate estimation of the output electric signal derived from the orbital variation of radiant exitance from the Sun and the Earth arriving at the aperture and detector plane of the Amon-Ra. For this, orbital irradiance are computed analytically first and then confirmed by simulation using Integrated Ray Tracing (IRT) model. Specially, the results show the arriving power at the bolometer detector surface is $1.24{\mu}W$ for the Sunlight and $1.28{\mu}W$ for the Earthlight, producing the output signal pulses of 34.31 mV and 35.47 mV respectively. These results demonstrate successfully that the arriving radiative power is well within the bolometer detector dynamic range and, therefore, the proposed detector can be used for the in-orbit measurement sequence. We discuss the computational details and implications as well as the simulation results.

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Quantitative Analysis of Vitamin B5 and B6 Using High Performance Liquid Chromatography (고속액체크로마토그래피를 이용한 비타민 B5 및 B6의 정량 분석)

  • Kim, Gi-Ppeum;Hwang, Young-Sun;Choung, Myoung-Gun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.10
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    • pp.1186-1194
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    • 2017
  • Recently, many people have demanded reliable nutritional data even for minor-components. On the other hand, an analytical method for the analyses of vitamin $B_5$ and $B_6$ is lacking. Therefore, this study attempted to validate with accuracy and precision the analysis of vitamin $B_5$ and $B_6$ using a high-performance liquid chromatography (HPLC) method. The vitamin $B_5$ and $B_6$ contents were analyzed using an Agilent 1260 series HPLC system. YMC-Pack ODS-AM ($250{\times}4.6mm$ I.D.) and YMC-Pack Pro RS $C_{18}$ ($250{\times}4.6mm$ I.D.) columns were used for the analyses of vitamin $B_5$ and $B_6$, respectively. In the case of vitamin $B_5$, the flow rate was set to 1.0 mL/min by isocratic elution using the 50 mM $KH_2PO_4$ solution (pH 3.5)/acetonitrile (ACN) (95:5, v/v) with monitoring at 200 nm using HPLC/DAD, whereas the flow rate for vitamin $B_6$ was set to 1.0 mL/min of flow rate by isocratic elution using a 20 mM $CH_3CO_2Na$ solution (pH 3.6)/ACN (97:3, v/v) with monitoring by excitation at 290 nm and emission at 396 nm using HPLC/FLD. The column temperature was set to $30^{\circ}C$. The injection volume was $20{\mu}L$ for each experiment. The specificity of the accuracy and precision for vitamin $B_5$ and $B_6$ were also validated by HPLC. The results showed high linearity in the calibration curve for vitamin $B_5$ ($R^2=0.9998^{{\ast}{\ast}}$), the limit of detection (LOD) and limit of quantitation (LOQ) were 0.4 mg/L and 1.3 mg/L, respectively, In contrast, for the calibration curve of vitamin $B_6$, which showed high linearity ($R^2=0.9999^{{\ast}{\ast}}$), the LOD and LOQ were 0.006 mg/L and 0.02 mg/L, respectively.