• Title/Summary/Keyword: LC

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Leakage Current Waveforms of Outdoor Polymeric Insulators and Possibility of Application for Diagnostics of Insulator Conditions

  • Suwarno Suwarno
    • Journal of Electrical Engineering and Technology
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    • v.1 no.1
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    • pp.114-119
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    • 2006
  • This paper reports the investigation results on the leakage currents (LC) on polymeric outdoor insulators. The samples used were EPDM (ethylene prophylene diene monomer) insulators used at 20 kV distribution lines. AC voltage was applied and the LC waveforms were measured under various environmental conditions (humidity and pollution). Digital data of the LC was transferred from a digital storage oscilloscope to a computer for further analysis. The LC waveform parameters such as magnitude and harmonic content (as indicated by the total harmonic distortion (THD)) were analyzed. The experimental results showed that 3rd, 5th and 7th harmonics and higher odd harmonics were observed for symmetrical-distorted LC waveforms while for unsymmetrical-distorted LC waveforms, odd and even harmonics were observed. The LC analysis indicated that there are 5 stages of insulator conditions from normal condition up to flashover correlated with different kind of LC waveforms. The results also showed that in general the magnitude of LC was good enough to show the condition of the insulators. However, under discharge condition (for example as a result of dry band arching) the LC magnitude should be combined by the THD to show a better correlation with the insulator condition. The product between THD and LC magnitude may be used as a diagnostic parameter.

Study of the Electro-Optic Characteristics Depending on Electric Characteristic of the Black Matrix in a Homogeneous Liquid Crystal Cell Driven by Fringe-Electric Field (프린즈 전기장에 의해 구동되는 수평 배향 액정셀에서 black matrix의 전기적 특성이 셀의 전기광학 특성에 미치는 영향에 관한 연구)

  • 김미숙;김향율;고재완;이승희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.11
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    • pp.1008-1013
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    • 2003
  • We have studied the effect of black matrix (BM) according to the dielectric anisotropy of liquid crystals (LCs) for a homogeneously aligned LC cell driven by fringe-electric field. The results show that for a LC with positive dielectric anisotropy (+LC) there is a large transmittance change when using a conductive BM, whereas the transmittance change is low for a LC with negative dielectric anisotropy (-LC). The conductive BM existing on top substrate produces vertical electric field, which makes the LC molecules be tilt upward from the substrate and have small twist angle for the +LC. However, for the -LC the conductive BM affects the LC distribution only slightly due to characteristic of the -LC orienting perpendicular to the field. Therefore, for the +LC the electro-optic characteristics are strongly dependent on conductivity of the BM on top substrate in a homogeneous liquid crystal cell driven by fringe-electric field.

Comparison of 2-D RP-RP MS/MS with 1-D RP MS/MS for Proteomic Analysis (단백체 분석을 위한 일차원 및 이차원 역상크로마토그래피의 비교)

  • Moon, Pyong-Gon;Cho, Young-Eun;Baek, Moon-Chang
    • YAKHAK HOEJI
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    • v.54 no.5
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    • pp.377-386
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    • 2010
  • Single-dimensional (1-D) and two-dimensional (2-D) LC methods were utilized to separate peptides from various sources followed by MS/MS analysis. Two-dimensional ultra-high performance liquid chromatography is a useful tool for proteome analysis, providing a greater peak capacity than 1-D LC. The most popular 2-D LC approach used today for proteomic research combines strong cation exchange and reversed-phase LC. We have evaluated an alternative mode for 2-D LC of peptides using 2-D RP-RP nano UPLC Q-TOF Mass Spectrometry, employing reversed-phase columns in both separation dimensions. As control experiments, we identified 129 proteins in 1-D LC and 322 proteins in 2-D LC from E. coli extract peptides. Furthermore, we applied this method to rat primary hepatocyte and a total of 170 proteins were identified from 1-D LC, and 527 proteins were identified from all 2-D LC system. The in-depth protein profiling established by this 2-D LC MS/MS from rat primary hepatocyte could be a very useful reference for future applications in regards to drug induced liver toxicity.

Vertical Alignment of Liquid Crystal on Film of Plant-based Polysaccharide Derivatives

  • Yeonsu Cho;Jihyeon Moon;DaEun Yang;Hyo Kang
    • Elastomers and Composites
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    • v.58 no.1
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    • pp.1-10
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    • 2023
  • In this study, we investigate the liquid crystal (LC) alignment of LC cells created from plant-based polysaccharide derivatives, such as guar gum. Guar gum films exhibit satisfactorily high optical transparency in the visible light region (400-750 nm). For example, the transmittance of polyimide films, which are the most typically used LC alignment layers, is 87%, whereas that of guar gum films deposited onto a glass substrate at a wavelength of 550 nm is approximately 99%. The observed LC alignment depends on the rubbing depth. For example, an LC cell comprising a guar gum film fabricated via rubbing at rubbing depths of 0.1, 0.2, 0.3, and 0.4 mm exhibits a planar LC alignment, whereas it exhibits a vertical LC alignment at a rubbing depth of 0.5 mm. Additionally, the LC alignment is shown to be correlated with the total surface energy of the guar gum films. When the total surface energy of a rubbed guar gum film exceeds 58.10 mJ/m2, an LC cell comprising the guar gum film exhibits a stable and vertical LC alignment. Therefore, guar gum can be used to realize the vertical alignment system of LC via a simple adjustment of the rubbing depth.

Molecular Cloning and Expression of Cellulase of Gene of Pseudomonas sp. in Escherichia coli (Pseudomonas sp.의 Cellulase 유전자의 대장균에의 클로닝 및 발현)

  • 정영철;김양우;노종수;성낙계;강신권
    • Microbiology and Biotechnology Letters
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    • v.18 no.6
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    • pp.633-639
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    • 1990
  • The genes for cellulases of Pseudomonas sp. LBC505 and CYC10, potent cellulase complex-producing strains, were cloned in Escherichia coli with pUC19. Recombinant plasmids pLCl and pLC2 were isolated from transformants producing cellulase by Congo red staining, and their genes cloned were 0.7 kb and 4.6 kb HindIII fragments, respectively. The inserts of pLCl and pLC2 were hybridized to chromosomal DNAs digested with HindIII from Pseudomona~ sp. LBC505 and CYC10, respectively. Immunodiffusion assays revealed that pLC1-and pLC2-encoded cellulase showed similarity with that of host strains. About 24% of cellulase activity was observed in the extracellular fraction of E. coli carrying pLC1, and its activity was higher about 1.4 times than that of LBC505. The enzymatic properties of pLC1 and pLC2 encoded cellulase were the same as those of cellulase from host strains. HPLC analysis and substrate specificity showed that cellulases were the same as those of cellulase from host strains. HPLC analysis and substrate specificity showed that cellulases cloned were endocellulase.

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The Effect of Yindong on Gout of Rats induced by Monosodium Urate (인동(忍冬)이 Monosodium Urate로 유발(誘發)된 백서(白鼠)의 통풍(痛風)에 미치는 영향(影響))

  • Lee, Hong-Jin;Cho, Chung-Sik;Kim, Chul-Jung
    • Journal of Haehwa Medicine
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    • v.17 no.1
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    • pp.83-93
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    • 2008
  • In order to study the Effects of yindong(LC) on the variation of blood and joint value the gout induced by microcrystalline sodium urate in rats, for LC is one of the important medicine on gout. After pretreatment of LC(50, 500mg/kg) for 5days, the Effects of LC was evaluated on Serum albumin, Serum globulin, glutamate dxalacetate transminase(AST), glutanate pyruvate transminase(ALT), blood urea nitrogen(BUN), Serum creatitine, Serum uric acid, xanthine oxidase activity, Erythrocyte Sedimentation Rate(ESR), WBC, platelet were measured. The results were obtained as follows : Joint value Increase ratio was not significantly decreased in all LC taken groups compared with the control group. Serum albumin was significantly different in all LC taken groups compared with the control group and Serum globulin was significantly dicreased in 500mg/kgLC taken group compared with the control group. Serum AST, ALT were significantly dicreased in 500mg/kgLC taken group compared with the control group. Serum BUN was significantly decreased in all LC taken groups and Serum creatinine was significantly decreased in 500mg/kgLC taken group compared with the control group. Serum uric acid was significantly different in 500mg/kgLC taken group, and changes in xanthine oxidase activity was significantly decreased in 500mg/kg, 50mg/kgLC taken group. ESR was significantly decreased in all LC taken groups compared with the control group. WBC, platelet count were significantly decreased in 500mg/kgLC taken group compared with the control group. From above results it may be concluded that Yindong can be used for treatment and preventive medcine of gout induced by microcrystalline sodium urate in clinic.

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10 GHz LC Voltage-controlled Oscillator with Amplitude Control Circuit for Output Signal (출력 신호의 진폭 제어 회로를 가진 10 GHz LC 전압 제어 발진기)

  • Song, Changmin;Jang, Young-Chan
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.975-981
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    • 2020
  • A 10 GHz LC voltage-controlled oscillator (VCO), which controls an amplitude of output signal, is proposed to improve the phase noise. The proposed amplitude control circuit for the LC VCO consists of a peak detector, an amplifier, and a current source. The peak detector is performed detecting the lowest voltage of the output signal by using two diode-connected NMOSFET and a capacitor. The proposed 10 GHz LC VCO with an amplitude control circuit for output signal is designed using a 55 nm CMOS process with a supply voltage of 1.2 V. Its area is 0.0785 ㎟. The amplitude control circuit used in the proposed LC VCO reduces the amplitude variation 242 mV generated in the output signal of the conventional LC VCO to 47 mV. Furthermore, it improves the peak-to-peak time jitter from 8.71 ps to 931 fs.

Electron Microscopic and Rheological Studies of Mozzarella Cheese Manufactured using Streptococcus macedonicus LC743 (Streptococcus macedonicus LC743으로 제조된 모짜렐라 치즈의 물성학적, 전자현미경적 연구)

  • Han, Noori;Park, Sun-Young;Lim, Sang-Dong
    • Journal of Dairy Science and Biotechnology
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    • v.33 no.4
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    • pp.247-252
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    • 2015
  • The aim of this study was to evaluate the electron microscopic and rheological properties of Mozzarella cheese manufactured using Streptococcus macedonicus LC743. The rheological properties of the pre-cut curd samples processed with S. macedonicus LC743 showed a weaker texture than those processed with a commercial starter, but showed a similar or stronger texture than those processed with mixed cultures (S. macedonicus LC743 plus the commercial starter). Cheese made with S. macedonicus LC743 showed higher values of hardness, springiness, cohesiveness, gumminess, and chewiness compared to those made with the commercial starter and mixed cultures. Scanning electron microscopy micrographs showed that the cheese manufactured with the commercial starter had a rough surface, whereas that manufactured with S. macedonicus LC743 had casein micelles that were agglomerated in small lumps and formed a small valley.

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Screening of Potential Compounds Promoting BDNF Production in Noradrenergic Locus Coeruleus Neurons (노르아드레날린성 신경세포에서의 BDNF 생산 증진 물질 탐색)

  • 전홍성
    • KSBB Journal
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    • v.18 no.3
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    • pp.207-210
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    • 2003
  • The locus coeruleus (LC) contains about half of the total number of noradrenergic neurons in the brain and those noradrenergic neurons from the LC innervate entire brain regions. The LC is a major common target region in several neurodegenerative disorders such as Alzheimer's, Pakinson's and Huntington's diseases. The brain-derived neurotrophic factor (BDNF) regulate neuronal cell survival and differentiation of central nervous system neurons, including LC noradrenergic neurons. In this study, various small molecules and growth factors were tested as candidates to promote the production of BDNF in LC noradrenergic neuronal cells. The molecules tested include neuropeptides, cytokines, growth factors, neurotransmitters, and intracellular signaling agents. Four small molecules or growth factors, FGF8b, BMP-4, forskolin, and dibutyryl cGMP, were found to increase the release of BDNF in LC noradrenergic neurons. Especially, BMP-4 significantly enhanced BDNF production over 2.5-fold in LC noradrenergic neurons.

A SAW-less GPS RX Front-end using an Automatic LC Calibrator (자동변환 LC 캘리브레이터를 이용한 SAW 필터 없는 GPS RX 프론트앤드 구현)

  • Kim, Yeon-Bo;Moon, Hyunwon
    • Journal of Korea Society of Industrial Information Systems
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    • v.21 no.1
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    • pp.43-50
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    • 2016
  • In this paper, new automatic LC calibrator is proposed for realizing a passive LC filter with almost constant frequency characteristic regardless of the PVT variations. The SAW-less GPS RX front-end is implemented using a 65nm CMOS process using the proposed LC calibrator. Also, new dual-mode low noise amplifier (LNA) structure is proposed to generate the RF signal required for the LC calibrator. The characteristics of the implemented GPS RX front-end show the voltage gain of about 42.5 dB, noise figure of below 1.35 dB, the blocker input P1dB of -24 dBm in case of the worst blocker signal at 1710 MHz frequency, while it consumes 7 mA current at 1.2 V power supply voltage.