• Title/Summary/Keyword: CV characteristics

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A Study on Physical Properties of Carbon Nitride Films and Application of Sensor Materials (질화탄소막의 물리적 특성과 센서재료 응용에 관한 연구)

  • Kim, Sung-Yeop;Lee, Ji-Gong;Chang, Choong-Won;Lee, Sung-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.247-248
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    • 2006
  • Carbon nitride films were evaluated that they had many advantages for miniature micro-humidity-sensors using the standard CMOS technology humidity sensing properties and CV characteristics of the carbon nitride films have been investigated for fabricating one chip HUSFET(Humidity Sensitive Field Effect Transistor) humidity sensors Carbon nitride films were deposited on silicon substrate with meshed electrodes by reactive RF magnetron sputtering system. The capacitor-type humidity sensor revealed good humidity-impedance characteristics with a wide range of relative humidity changes, decreasing $254k{\Omega}$ to $16k{\Omega}$ according to increase of relative humidity between 5% ~ 95% and the films were very stable on the Si wafer. These results reveal that $CN_x$ thin films can be used for Si based or HUSFET structure one chip micro-humidity sensors.

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Preparation and Electrochemical Characteristics of DAAQ/CNFs Composite electrode for Supercapacitor (DAAQ가 코팅된 슈퍼커패시터용 CNFs전극 활물질의 제조 및 전기 화학적 특성)

  • Kim, Hong-Il;Choi, Weon-Kyung;Park, Soo-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1226-1229
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    • 2004
  • Supercapacitors, also known as electrochemical capacitors, are being extensively studied due to an increasing demand for energy-storage systems. These devices offer many advantages over conventional secondary batteries, which include the ability of fast charge propagation, long cycle-life and better storage efficiency. That is to say supercapacitor bridges the gap between conventional capacitors and batteries. A new type electric double layer capacitor (EDLC) also called supercapacitors. Recently, supercapacitors concerns about their high power density and energy density. So we experiment with EDLC by using carbon nanofibers (CNFs) and DAAQ(1,5-diaminoanthraquinone) electrode. The electrode for supercapacitor was prepared by synthesis of DAAQ covered CNFs. CNFs could be covered with very thin DAAQ oligomer from the results of CV, XRD, DSC, SEM images, and TEM images. Dissolved electrode active material in NMP solution has been drop-coated on carbon plate. Its electrochemical characteristics were investigated by cyclic voltammograms. And compared with different electrolyte of aqueous type. As a result, CNFs coated by DAAQ composite electrode showed relatively good electrochemical behaviors with respect to specific capacity and scan rate dependency.

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Study of the Electrochemical Redox Characteristics of Some Triazolopyrimidines

  • Maghraby, A.A. El;Elenien, G.M. Abou;Shehata, K.I.
    • Journal of the Korean Electrochemical Society
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    • v.10 no.3
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    • pp.159-168
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    • 2007
  • An electrochemical study related to the redox characteristics of Ethyl-3-acetyl-6-methyl-1, 4-diphenyl-4, 3a-dihydro-1, 3, 4-triazolino[3, 4-a] pyrimidine-5-carboxylate ester and its derivatives (1a-f) and (2a-e) in nonaqueous solvents such as 1, 2-dichloroethane (DCE), dichloromethane (DCM), acetonitrile (AN), dimethylsulphoxide (DMSO) and tetrahydrofurane (THF) using $0.1\;mol\;dm^{-3}$ tetrabutylammonium perchlorate (TBAP) as a supporting electrolyte at platinum, glassy carbon and gold electrodes, has been performed using cyclic voltammetry (CV). Controlled potential electrolysis (CPE) is also carried out to elucidate the course of different electrochemical reactions through the separation and identification of the intermediates and final electrolysis products. The redox mechanism is suggested and proved. It was found that all the investigated compounds in all solvents are oxidized in a single irreversible one electron donating process following the well known pattern of the EC-mechanism to give a dimer. On the other hand, these compounds are reduced in a single irreversible one electron step to form the anion radical, which is basic enough to proton from the media forming the radical which undergoes tautomerization and then dimerization processes to give also another bis-compound through N-N linkage formation.

Relationship of Growth Characteristics and Leaf Surface Lipid of Tobacco (잎담배의 엽면수지량과 생육형질과의 관계)

  • Jeong, Gi-Taek;Ban, Yu-Seon;Yu, Ik-Sang
    • Journal of the Korean Society of Tobacco Science
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    • v.5 no.2
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    • pp.33-38
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    • 1983
  • This experiment was conducted to investigate effects of fertilizers on leaf surface lipid(LSL) , and relationship between growth characteristics and LSL of aromatic tobacco, cv. Sohyang, grown in pots with 3 rates of N, P and K. With increasing the amount of applied nitrogen from 3 to 6kg110a, the contents of LSL per plant and per leaf area were decreased For maximum LSL Per plant and per leaf area nitrogen of 3kg/10a was required ,There were lit tie affected by P and K. Leaf weight per plant and mean leaf area were correlated significantly and positively with LSL per plant, but thickness of largest leaf negatively. Specific leaf weight and leaf dry weight /leaf fresh weight ratio were correlated significantly and positively with LSL per leaf area, but mean leaf area negatively.

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Review on the Quantitative Standards for Twirling Supplementation and Draining (염전보사의 정량적 기준에 대한 고찰)

  • Park, Jin Ah;Lee, Sang-Ryong
    • Korean Journal of Acupuncture
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    • v.33 no.4
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    • pp.149-156
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    • 2016
  • Objectives and Methods : The aim of this study was to investigate twirling and supplementation and draining by analyzing ancient acupuncture literature and modern research papers, and to discuss the quantitative standards for the procedure. Results : Twirling supplementation and draining techniques were first described in Huang do neijing, after which they were recorded in various other ancient acupuncture texts. Not only were these techniques used in the active treatment of patient historically, but they also form the foundations of modern-day acupuncture treatment. Twirling supplementation and draining techniques described in ancient literatures can be divided into Yin and Yang. Examples of Yang characteristics include Up, Male, Morning, Hands, the governor vessel, Outside, and Left. The left rotation technique is a reinforcing method performed by moving the thumb forward while rotating the needle. Examples of Yin characteristics include Down, Female, Afternoon, Foot, the conception vessel(CV), Inside, and Right. The right rotation technique is a reducing method performed by moving the thumb backward while rotating the needle. Twirling supplementation and draining has been divided for four ways by classical literature and research that worked before. the direction of acupuncture, the stimulus-quantity of acupuncture, the performance of doctor(the uses of both hands, left and right hand) and the feeling of patient. Conclusions : Therefore, continuous research is required to implement Twirling supplementation and draining in a consistent manner. In addition, more active clinical trials using the techniques are necessary as well.

A Study on the Optimization of Interfacial Pressure for the Stress Relief Cone in the Ultra-High Voltage Level Prefabricated Type Joint Box (초초고압 CV Cable용(用) 조립형 직선 접속함에서의 Stress Relief Cone 계면압력 최적화에 관한 연구)

  • Baek, J.H.;Baek, S.Y.;Lee, S.K.;Huh, G.D.;Park, W.K.
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1614-1616
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    • 1998
  • Insulation performance of major components of prefabricated joint such as epoxy insulation unit and premolded rubber cone are guaranteed by material selection design and proper manufacturing. On the other hand insulation performance of the interfaces between the premolded rubber cone and the epoxy insulation unit and the cable insulation is maintained by keeping the premolded rubber cone to close contact with such insulation by spring. Electric characteristics of a interface depend on the contact pressure, but the required characteristics are assured so far as a proper contact pressure is maintained. In this report, the interfacial pressure by pressure sensors both in the early stage and after heating cycle were measured and the simulation by FEM program were presented. The comparison of these two results show that interfacial pressure could be controlled optimally by changing the spring length and lubricant state of the interface.

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Fertilizer Placement Effect on Agronomic Characteristics of Burley Tobacco(N. tabacum L.) (시비방법이 버어리종 잎담배의 농경적 특성에 미치는 영향)

  • 조천준;배성국;임해건;김요태
    • Journal of the Korean Society of Tobacco Science
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    • v.19 no.1
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    • pp.33-39
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    • 1997
  • Recently the method of basal compound fertilizer (N : P : K = 18.2 : 9.8 : 35.0) Placement has been changed from banding to broadcasting in tobacco cultivation. The effects of the compound fertilizer placement, level of fertilizer and additional urea application on the agronomic characteristics, two chemical compositions and physical Properties of burley tobacco(Nicotiana tabacum L. cv. KB 108) were investigated at Chonju Experiment Station, Korea Ginseng and Tobacco Research Institute in 1995-1996. Six treatments consisted of (1) band (method of fertilizer Placement) + In kg/10a(compound fertilizer) + 0(additional urea applied), (2) broadcast+140+0, (3) broadcast+140+25, (4) band+180+0, (5) broadcast+180+0, and (6) broadcast +180+25. The additional urea was applied at hilling. No significant differences were detected between banding and broadcasting method of compound fertilizer Placement in field 9rowth, wield, organoleptic qualify(price Per kilogram), chemical composition and Physical properties of cured leaf, The increased compound fertilizer by 30%(40k/10a) or the additional urea application by 25kg per 10a produced slightly higher yield than the recommended amount of basal compound fertilizer without additional urea application did. It also increased the total alkaloid content of cured leaf. It is recommended that no more basal fertilizer above the recommended amount and no additional urea application are needed in burley tobacco fertilization, even though the method of basal fertilizer placement being chanced from banding to broadcasting. Key words : Nicotiana tabacum, fertilizer placement, additional urea.

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Electrochemical Characteristics of Porous Modified Silicon Impregnated with Metal as Anode Materials for Lithium Secondary Batteries (리튬 이차전지용 금속이 담지된 다공성 실리콘 음극물질의 전기화학적 특성)

  • Jang, Eun-Jung;Jeon, Bup-Ju
    • Journal of Hydrogen and New Energy
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    • v.23 no.4
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    • pp.353-363
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    • 2012
  • The relationship between the diffusivity and electrochemical characteristics of lithium secondary battery with the modified Si anode material prepared in HF/$AgNO_3$ solution was investigated. The crystallographic structure and images of the modified porous Si and modified Si/Cu was examined using the X-ray diffraction, BET and SEM. To examine the effect of metal composite and pore size distribution according to chemical etching on the electrochemical characterization, the electrodes for half cells were prepared with the modified Si, modified Si/Cu, and modified Si/Cu annealed with $600^{\circ}C$. Our results showed that the chemical diffusivity of lithium ions was related to structure and resistance of Si/Cu composite anode material. The lithium diffusivity in modified silicon compound calculated from the CV was at the range of $1{\times}10^{-12}$ to $9{\times}10^{-16}cm^2/s$. The effects of modified silicon structure and resistance on the cycling efficiency were significant.

A Novel MPPT Control of a Photovoltaic System using an FLC Algorithm

  • Ko, Jae-Sub;Chung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.11
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    • pp.17-25
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    • 2014
  • This paper proposes a novel maximum power point tracking (MPPT) system using a fuzzy logic control (FLC) algorithm for robust in-environment changing. The power available at the output of a photovoltaic (PV) cell continues to change with radiation and temperature because a solar cell exhibits nonlinear current-voltage characteristics. Therefore, the maximum power point (MPP) of PV cells varies with radiation and temperature. The MPPT methods are used in PV systems to make full utilization of the PV array output power, which depends on radiation and temperature. The conventional MPPT control methods such as constant voltage (CV), perturbation and observation (PO) and incremental conductance (IC) have been studied but these methods are problematic in that they fail to take into account the changing environment. The proposed FLC controller is based on the fuzzy control algorithm and facilitates robust control with the environmental changes. Also, the PV systems applied FLC controller is modeled by PSIM and the response characteristics of the FLC method according to environmental variations are analyzed through comparison with the performance of conventional methods. The validity of this controller is shown through response results.

Morphological Characteristics of the Green Peach Aphid, Myzus persicae (Sulzer) (Homoptera : Aphididae) Occurring in Tobacco Fields and Its Experimental Transmission of Potato Virus Y (담배 재배 포장에서 발생하는 복숭아혹진딧물의 형태적 특징 및 감자 바이러스 Y의 실험적 전염)

  • 채순용;김영호;김상석;박은경
    • Journal of the Korean Society of Tobacco Science
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    • v.17 no.1
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    • pp.49-56
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    • 1995
  • Morphology, chromosome and transmission of potato virus Y(PVY) of the green peach aphid populations collected from tobacco fields were examined. Based on the morphological characteristics, especially values of linear discriminant functions and length of ultimate rostral segment, 8 green peach aphid clones with different color morphs could be divided into two groups, namely Myzus persicae and M. nicotianae, according to the proposal by Blackman in 1987. The red (RED)-, Brown (BRN)- and green-colored (GR1, GR2) aphid clones belonged to the M. nicotianae type, while the pale green (PG1, PG2, PG3) and dark brown (DBR) clones to the M. persicae type. The karyotype of the pale green-colored clone (PG1, M. persicae type) appeared normal and was 2n=12 with no indication of chromosomal translocation. On the contrary, in the green-colored aphid clone (GR1, M. nicotianae type), translocation and dissociation of autosome 3 were often found, having karyotype of 2n=13. Both of the above aphid clones transmitted PVY-VN to tabacco plants (cv. Burley 21), but the GR1 clone had higher transmissibility than the PG1 clone.

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