• Title, Summary, Keyword: multiple cathode system

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Development of Biosensor for Simultaneous Determination of Glucose, Lactic Acid and Ethanol (포도당, 젖산 및 에탄올의 동시 측정용 바이오센서의 개발)

  • Kim, Jung-Ho;Rhie, Dong-Hee;Kim, Tae-Jin;Noh, Bong-Soo
    • Korean Journal of Food Science and Technology
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    • v.30 no.1
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    • pp.22-34
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    • 1998
  • The purpose of this study is to develop biosensor for determination of glucose, lactate, and ethanol in foods and food-stuffs simultaneously. The multiple cathode system was prepared with an oxygen electrode having one anode and hexagonal cathode. Glucose oxidase, mutarotase, lactate oxidase, alcohol oxidase and catalase were used for immobilization to determine glucose, lactate, and ethanol. These components including ethanol were simultaneously determined by the immobilized enzymes in the multiple cathode system. The determination of the components by enzyme sensor was based on the maximum slope of oxygen consumption from enzyme reaction of each sensor part. The response time for analysis was 1 min. The optimum condition for glucose, lactate and ethanol sensor was found to be 0.1 M potassium phosphate buffer, pH 7.0 at $40^{\circ}C$. Interferences of various sugars and organic acids were investigated. Less than 10% of error was found in determination of the components except organic acids. This difference was compensated by the modified equation. This system was confirmed by conventional methods. It was concluded that the multiple cathode system of this study is for an effective method to determine sugar, organic acid, ethanol simultaneously in foods.

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A Study on the Parallel Drive of Cold Cathode Fluorescent Lamp (CCFL) (냉음극 형광램프의 병렬구동에 관한 연구)

  • Kim, Cherl-Jin;Park, Hyun-Cherl;Park, Jung-Oh
    • Proceedings of the KIEE Conference
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    • pp.149-151
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    • 2008
  • This paper presents an architecture for driving multiple parallel cold cathode fluorescent lamps (CCFLs) for back lighting applications. The key to the architecture is a proposed capacitive coupling approach for lamp ignition. This system is consist of a flyback converter, a single inverter to drive multiple lamps and conductive floating reflector. The topology is capable of driving a number of parallel lamps with independent accurate lamp, current regulation and improving cost effectiveness with significant reduction in size and weight, compared to typical high frequency ac ballast. Experimental demonstration results for ten of parallel CCFLs with simultaneous ignition.

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Simultaneous measurement of oxygen permeability by using of multi-functional oxygen electrode (다기능 산소전극에 의한 산소투과특성 동시측정)

  • 이동희;정진휘;유형풍;김태진
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.532-535
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    • 2000
  • We have fabricated a sensor system for on-line monitoring the oxygen permeability and diffusivity of six different polymer films using the miniaturized 6 cathode(Ag)-single anode(Ag/AgCl) type hexagonal oxygen electrode. This system consists of multiple input front-end electronics, signal conditioning circuit using the embedded microcontroller 80C196KC, PC interface circuit and PC with the OS for microcontroller and the operating program for this system. The digital low-[ass filter was programmed and the simulated filter characteristics were enough to eliminate the noise from sensor signal. According to the experimental results, the linearity coefficients of the output voltage to oxygen partial pressure for each sensor electrode of six cathode type oxygen sensor are 0.998, 0.997, 0.998, 0.997, 0.997, 0.997 respectively, and the response times are all within 4 minutes.

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A New Current Balancing Methods of CCFL for LCD TV Backlight (LCD 백라이트를 위한 새로운 CCFL 병렬구동 인버터)

  • Lee, Soung-Ju;Kim, Ho-Jin;Lee, Hai-Don;Mok, Hyung-Soo;Choe, Gyu-Ha;Yang, Seung-Uk
    • The Transactions of the Korean Institute of Power Electronics
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    • v.11 no.4
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    • pp.371-377
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    • 2006
  • Cold cathode fluorescent lamps (CCFL) show complex characteristics, which make it difficult to drive them in parallel. In this paper, a multi-lamp driving scheme is proposed to drive multiple lamps for LCD back light to reduce output current unbalance. This propose system is composed of parallel CCFLs, series transformers. The driving system adopts only one backlight inverter to drive multi cold cathode fluorescent lamps (CCFL). Moreover the circuit introduces a multi-lamp driving transformer to reduce lamp-current imbalance. The validity of the proposed scheme is confirmed by the simulated and experimental results.

A Study on the Multiple CCFL Operation and Brightness Improvement (다수의 CCFL 구동과 휘도 향상에 관한 연구)

  • Park, Jung-Oh;Kim, Cherl-Jin;Park, Hyun-Cherl
    • Proceedings of the KIEE Conference
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    • pp.126-128
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    • 2008
  • This paper presents an architecture for driving multiple paralleled cold cathode fluorescent lamps (CCFLs) for back lighting applications. Multi CCFL operation and increase of brightness, the key to the architecture is a proposed capacitive coupling approach for lamp ignition. This system is consist of a flyback converter, a single inverter to drive multiple lamps and conductive floating reflector. The topology is capable of driving a number of parallel lamps with independent accurate lamp, The capacitive coupling the leakage inductance and stray capacitance creation which it used, current regulation and improving cost effectiveness with significant reduction in size and weight, compared to typical high frequency ac ballast. Experimental demonstration results for ten of parallel CCFLs with simultaneous ignition.

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Tribology Coating Study of Thick DLC (ta-C) Film (DLC (ta-C) 후막코팅을 위한 트라이볼로지 코팅 연구)

  • Jang, Young-Jun;Kang, Yong-Jin;Kim, Gi Taek;Kim, Jongkuk
    • Tribology and Lubricants
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    • v.32 no.4
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    • pp.125-131
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    • 2016
  • In recent years, thick ta-C coating has attracted considerable interest owing to its existing and potential commercial importance in applications such as automobile accessories, drills, and gears. The thickness of the ta-C coating is an important parameter in these applications. However, the biggest problems are achieving efficient coating and uniformity over a large area with high-speed deposition. Feasibility is confirmed for the ta-C coating thickness of up to 9.0 µm (coating speed: 3.0 µm/h, fixed substrate) using a single FCVA cathode. The thickness was determined using multiple coating cycles that were controlled using substrate temperature and residual stresses. In the present research, we have designed a coating system using FCVA plasma and produced enhanced thick ta-C coating. The system uses a specialized magnetic field configuration with stabilized DC arc plasma discharge during deposition. To achieve quality that is acceptable for use in automobile accessories, the magnetic field, T-type filters, and 10 pieces of a multi-cathode are used to demonstrate the deposition of the thick ta-C coating. The results of coating performance indicate that uniformity is ±7.6 , deposited area is 400 mm, and the thickness of the ta-C coating is up to 5.0 µm (coating speed: 0.3 µm/h, revolution and rotation). The hardness of the coating ranges from 30 to 59 GPa, and the adhesion strength level (HF1) ranges from 20 to 60 N, depending on the ta-C coating.

Parallel Operation of CCFLs Considering on Capacitive Coupling (용량성 결합을 고려한 CCFL 병렬 구동)

  • Park, Jung-Oh;Kim, Cherl-Jin;Park, Hyun-Chul
    • Proceedings of the KIEE Conference
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    • pp.1007-1009
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    • 2008
  • This paper presents an architecture for driving multiple paralleled cold cathode fluorescent lamps (CCFLs) for back lighting applications. The key to the architecture is a proposed capacitive coupling approach for lamp ignition. This system is consist of a flyback converter, a single inverter to drive multiple lamps and conductive floating reflector. The topology is capable of driving a number of parallel lamps with independent accurate lamp, current regulation and improving cost effectiveness with significant reduction in size and weight, compared to typical high frequency ac ballast. Experimental demonstration results for ten of parallel CCFLs with simultaneous ignition. This like the EEFL it will be able to use the CCFL is the thing. Also, it investigates the effect where the leakage current goes mad to the Lamp.

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Shape Optimization of a CRT based on Response Surface and Kriging Metamodels (반응표면과 크리깅메타모델을 이용한 CRT 형상최적설계)

  • Lee, Tae-Hee;Lee, Chang-Jin;Lee, Kwang-Ki
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.3
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    • pp.381-386
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    • 2003
  • Gradually engineering designers are determined based on computer simulations. Modeling of the computer simulation however is too expensive and time consuming in a complicate system. Thus, designers often use approximation models called metamodels, which represent approximately the relations between design and response variables. There arc general metamodels such as response surface model and kriging metamodel. Response surface model is easy to obtain and provides explicit function. but it is not suitable for highly nonlinear and large scaled problems. For complicate case, we may use kriging model that employs an interpolation scheme developed in the fields of spatial statistics and geostatistics. This class of into interpolating model has flexibility to model response data with multiple local extreme. In this study. metamodeling techniques are adopted to carry out the shape optimization of a funnel of Cathode Ray Tube. which finds the shape minimizing the local maximum principal stress Optimum designs using two metamodels are compared and proper metamodel is recommended based on this research.

TOPSIS-Based Multi-Objective Shape Optimization for a CRT Funnel (TOPSIS 를 적용한 CRT 후면유리의 다중목적 형상최적설계)

  • Lee, Kwang-Ki;Han, Jeong-Woo;Han, Seung-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.7
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    • pp.729-736
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    • 2011
  • The technique for order preference by similarity to ideal solution (TOPSIS) is regarded as a classical method of multiple attribute decision making (MADM), often used to solve various decision-making or selection problems. It is based on the concept that the chosen alternative should have the shortest distance from the positive ideal solution and the farthest distance from the negative ideal solution. The TOPSIS can be applied to a design process for carrying out multi-objective shape optimization wherein the best and worst alternatives are to be decided. In this paper, multi-objective shape optimization using the TOPSIS and Rational Bezier curve was applied to the funnel of a cathode-ray tube (CRT). In order to minimize the weight and first principal stress, a new multi-objective shape optimization methodology is proposed, wherein the relative-closeness coefficients of the TOPSIS are defined as the performance indices of a multi-objective function and evaluated by response surface models. This methodology enables the designer to decide on the best solution from a number of design specification groups by examining the various conflicts between the weight and the first principal stress.

Radiation measurement and imaging using 3D position sensitive pixelated CZT detector

  • Kim, Younghak;Lee, Taewoong;Lee, Wonho
    • Nuclear Engineering and Technology
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    • v.51 no.5
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    • pp.1417-1427
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    • 2019
  • In this study, we evaluated the performance of a commercial pixelated cadmium zinc telluride (CZT) detector for spectroscopy and identified its feasibility as a Compton camera for radiation monitoring in a nuclear power plant. The detection system consisted of a $20mm{\times}20mm{\times}5mm$ CZT crystal with $8{\times}8$ pixelated anodes and a common cathode, in addition to an application specific integrated circuit. The performance of the various radioisotopes $^{57}Co$, $^{133}Ba$, $^{22}Na$, and $^{137}Cs$ was evaluated. In general, the amplitude of the induced signal in a CZT crystal depends on the interaction position and material non-uniformity. To minimize this dependency, a drift time correction was applied. The depth of each interaction was calculated by the drift time and the positional dependency of the signal amplitude was corrected based on the depth information. After the correction, the Compton regions of each spectrum were reduced, and energy resolutions of 122 keV, 356 keV, 511 keV, and 662 keV peaks were improved from 13.59%, 9.56%, 6.08%, and 5%-4.61%, 2.94%, 2.08%, and 2.2%, respectively. For the Compton imaging, simulations and experiments using one $^{137}Cs$ source with various angular positions and two $^{137}Cs$ sources were performed. Individual and multiple sources of $^{133}Ba$, $^{22}Na$, and $^{137}Cs$ were also measured. The images were successfully reconstructed by weighted list-mode maximum likelihood expectation maximization method. The angular resolutions and intrinsic efficiency of the $^{137}Cs$ experiments were approximately $7^{\circ}-9^{\circ}$ and $5{\times}10^{-4}-7{\times}10^{-4}$, respectively. The distortions of the source distribution were proportional to the offset angle.