• 제목/요약/키워드: CCP

검색결과 293건 처리시간 0.034초

A Study on the High Voltage CCPS Using a Resonant Frequency Tracking Type Series Resonant Inverter (공진주파수 추적형 직렬공진 인버터를 이용한 고전압 CCPS에 관한 연구)

  • Rho, Sung-Chan;Kim, Youn-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • 제19권7호
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    • pp.107-112
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    • 2005
  • RThis paper presents a high voltage capacitor charging power supply(CCPS) using a series resonant inverter. The CCPS adopted a 45[kHz] IGBT series resonant inverter using PLL control and a high-efficiency, high-voltage transformer. The performance test of the CCPS was carried out with a 14 nF load capacitor at 100[kV] output voltage and 200[Hz] repetition rate. Peak power rate of 18.75[kJ/sec] and charging time of 4.5[mS].

Modulation of Electroosmotic Flow through Skin: Effect of Poly(Amidoamine) Dendrimers

  • Kim, Hye Ji;Oh, Seaung Youl
    • Biomolecules & Therapeutics
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    • 제26권2호
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    • pp.182-190
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    • 2018
  • The objective of this work is to evaluate the effect of polyamidoamine (PAMAM) dendrimers on electroosmotic flow (EOF) through skin. The effect of size and concentration of dendrimer was studied, using generation 1, 4 and 7 dendrimer (G1, G4 and G7, respectively). As a marker molecule for the direction and magnitude of EOF, a neutral molecule, acetoaminophen (AAP) was used. The visualization of dendrimer permeation into the current conducting pore (CCP) of skin was made using G4-fluorescein isothiocyanate (FITC) conjugate and confocal microscopy. Without dendrimer, anodal flux of AAP was much higher than cathodal or passive flux. When G1 dendrimer was added, anodal flux decreased, presumably due to the decrease in EOF by the association of G1 dendrimer with net negative charge in CCP. As the generation increased, larger decrease in anodal flux was observed, and the direction of EOF was reversed. Small amount of methanol used for the preparation of dendrimer solution also contributed to the decrease in anodal flux of AAP. Cross-sectional view perpendicular to the skin surface by confocal laser scanning microscope (CLSM) study showed that G4 dendrimer-FITC conjugate (G4-FITC) can penetrate into the viable epidermis and dermis under anodal current. The permeation route seemed to be localized on hair follicle region. These results suggest that PAMAM dendrimers can permeate into CCP and change the magnitude and direction of EOF. Overall, we obtained a better understanding on the mechanistic insights into the electroosmosis phenomena and its role on flux during iontophoresis.

A study on establishment of bio-hazard analysis and critical control point for pork slaughter house (돼지도축장의 생물학적 위해요소에 대한 중요관리점 설정)

  • 옥천석;정지영;송은아;이성식
    • Korean Journal of Veterinary Service
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    • 제24권2호
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    • pp.117-126
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    • 2001
  • To ensure the safety of domestic livestock products, the government made it obligatory to enforce the hazard analysis critical control point(HACCP) in all domestic slaughterhouses. Under the HACCP, most of the hazards generated in slaughterhouses are bio-hazards, especially pathogenic bacteria. In order to reduce to the pathogenic bacteria, critical control point (CCP) is established and controled in the process of slaughter. A study was carried out to measure the level of bacterial contamination of swine carcass in 6 slaughterhouses selected. As a result, the aerobic plate counts(cfu/$\textrm{cm}^2$) of all samples was $10^2$-10 in average, except slaughterhouse C. The level of the aerobic plate counts on the surface of lower loin in slaughterhouse C was $10^4$ and it was considered that slaughterhouse C should set the process of manual transport of carcass as the CCP. Escherichia coli level was the highest in middle line cut surface. Especially, E coli level of slaughterhouses C and D were about 6.5- and 3.0-fold higher than that of other 4 slaughterhouses. Thus, it was considered that the slaughterhouses C and D should set the process of the entrails treatment as the CCP. The air contamination was measured at two point in a slaughterhouse. The air contamination level was 4-13 times higher than that of the standard Japanese slaughterhouses.

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Investigation of Spatial Distribution of Plasma Density between the Electrode and Lateral Wall of Narrow-gap CCP Source (좁은 간격 CCP 전원의 전극과 측면 벽 사이 플라즈마 분포)

  • Choi, Myung-Sun;Jang, Yunchang;Lee, Seok-Hwan;Kim, Gon-Ho
    • Journal of the Semiconductor & Display Technology
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    • 제13권4호
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    • pp.1-5
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    • 2014
  • The plasma density distribution in between the electrode and lateral wall of a narrow gap CCP was investigated. The plasma density distribution was obtained using single Langmuir probe, having two peaks of density distribution at the center of electrode and at the peripheral area of electrodes. The plasma density distribution was compared with the RF fluctuation of plasma potential taken from capacitive probe. Ionization reactions obtained from numerical analysis using CFD-$ACE^+$ fluid model based code. The peaks in two region for plasma density and voltage fluctuation have similar spatial distribution according to input power. It was found that plasma density distribution between the electrode and the lateral wall is closely related with the local ionization.

Current Source Type Pulse Generator with Improved Output Voltage Waveform for High Voltage Capacitively Coupled Plasma System (고전압 용량성 결합 플라즈마 시스템의 개선된 전압 파형 출력을 위한 펄스 전류 발생장치 회로)

  • Chae, Beomseok;Min, Juhwa;Suh, Yongsug;Kim, Hyunbae
    • The Transactions of the Korean Institute of Power Electronics
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    • 제24권3호
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    • pp.153-160
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    • 2019
  • This study proposes a current source-type pulse generator to improve output voltage and current waveforms under a capacitively coupled plasma (CCP) system. The proposed circuit comprises two parallel-connected current source-type converters. These converters can satisfy the required output waveforms of plasma processing. The parallel-connected converters operate without reverse current fault by applying a time-delay control technique. Conventional voltage source converters based on pulse power supply exhibit drawbacks in short-circuit current, and problems occur when they are applied to a CCP system. The proposed pulse power supply based on a current source converter fundamentally solves the short-circuit current problem. Therefore, this topology can improve the voltage and current accuracy of a CCP system.

Hazard Analysis, Determination of Critical Control Points, and Establishment of Critical Limits for Seasoned Laver (조미김의 제조공정별 위해요소분석, 중요관리점 결정 및 한계기준 개발)

  • Kang, Min Jeong;Lee, Hak Tae;Kim, Jung Yun
    • Culinary science and hospitality research
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    • 제21권2호
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    • pp.1-10
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    • 2015
  • The purpose of this study was to establish the critical limit of CCP (Critical Control Point) of a HACCP (Hazard Analysis Critical Control Point) system used in the production of seasoned laver products. The hazard analysis examined microbial evaluations and developed a HACCP management plan for the heating process. The results were determined to be capable of reducing the biological element of CCP via the secondary roasting process. This study examined general bacteria and pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, and Bacillus cereus at temperatures ranging from $170^{\circ}C$ to $230^{\circ}C$ and for 3.0 to 5.5 seconds at a time. Before the secondary roasting process, pathogenic microorganisms were all negative, although the presence of general bacteria was still detected. General bacteria was reduced to $1.0{\times}10CFU/g$ after the temperature was set at $230^{\circ}C$ for a period of 5.5 seconds. In conclusion, it suggested that a HACCP plan was necessary for management standard and systematic approach in the establishment of critical limit, problem resolution, verification method, education, and records management through a secondary roasting process.

Development of Large-area Plasma Sources for Solar Cell and Display Panel Device Manufacturing

  • Seo, Sang-Hun;Lee, Yun-Seong;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.148-148
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    • 2011
  • Recently, there have been many research activities to develop the large-area plasma source, which is able to generate the high-density plasma with relatively good uniformity, for the plasma processing in the thin-film solar cell and display panel industries. The large-area CCP sources have been applied to the PECVD process as well as the etching. Especially, the PECVD processes for the depositions of various films such as a-Si:H, ${\mu}c$-Si:H, Si3N4, and SiO2 take a significant portion of processes. In order to achieve higher deposition rate (DR), good uniformity in large-area reactor, and good film quality (low defect density, high film strength, etc.), the application of VHF (>40 MHz) CCP is indispensible. However, the electromagnetic wave effect in the VHF CCP becomes an issue to resolve for the achievement of good uniformity of plasma and film. Here, we propose a new electrode as part of a method to resolve the standing wave effect in the large-area VHF CCP. The electrode is split up a series of strip-type electrodes and the strip-type electrodes and the ground ones are arranged by turns. The standing wave effect in the longitudinal direction of the strip-type electrode is reduced by using the multi-feeding method of VHF power and the uniformity in the transverse direction of the electrodes is achieved by controlling the gas flow and the gap length between the powered electrodes and the substrate. Also, we provide the process results for the growths of the a-Si:H and the ${\mu}c$-Si:H films. The high DR (2.4 nm/s for a-Si:H film and 1.5 nm/s for the ${\mu}c$-Si:H film), the controllable crystallinity (~70%) for the ${\mu}c$-Si:H film, and the relatively good uniformity (1% for a-Si:H film and 7% for the ${\mu}c$-Si:H film) can be obtained at the high frequency of 40 MHz in the large-area discharge (280 mm${\times}$540 mm). Finally, we will discuss the issues in expanding the multi-electrode to the 8G class large-area plasma processing (2.2 m${\times}$2.4 m) and in improving the process efficiency.

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Studies on Preservation of Concentrated Milk by Freeze - Flow Process (Freeze - Flow Process 를 이용한 농축우유의 저장에 관한 연구)

  • Lee, Young-Chun;Shin, Dong-Bin
    • Korean Journal of Food Science and Technology
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    • 제17권6호
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    • pp.500-505
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    • 1985
  • A method to store concentrated milk in the liquid state at $-15^{\circ}C$ was developed, and quality changes during storage of milk were evaluated. Combined cryoprotectants (CCP) suitable for storing concentrated milk in the liquid state at $-15^{\circ}C$ were consisted of 17.74% sucrose, 8.87% glucose, 8.87% fructose, 2% glycerol, 0.25% sodium hexametaphosphate, 0.25% NaCl and 0.02% ascorbic acid. The amount of CCP to be added to concentrated milk to depress freezing point to $-15^{\circ}C$ was 38% by weight. Gelation due to protein denaturation was the most serious quality change during storage, which adversely affected appearance and utilization of the stored product. Gelation was observed after 3 weeks storage in the control, but it was not in milk with CCP throughout 18 weeks storage. Amount of protein precipitated increased in the control during storage, whereas there was no protein precipitated in milk with CCP. Surface color and peroxide value of the control and treatment did not change significantly during storage, and there were no marked differences between the control and treatment. These results indicated that quality of concentrated milk could be preserved, without gelation, by storing milk with CCP in the -liquid state at the frozen storage temperature. Besides, energy required for freezing preservation of milk could be significantly reduced by elimination of phase changes for freezing and thawing, and the stored product could be continuously processed for the final products without long waiting time for thawing.

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A Study on the Microbiological Analysis of BACCP in Hamburger (햄버거 제품에 대한 미생물학적 위해 요인 분석에 관한 연구)

  • 정일형;노완섭
    • The Korean Journal of Food And Nutrition
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    • 제14권5호
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    • pp.467-478
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    • 2001
  • This study was focused on the sanitary analysis of hazard factors and the establishment of critical control points on hamburger by the microbiological investigation. The degree of microorganic pollution on the ingredients and equipments for hamburger manufacturing and the variation of microorganisms at storage time and temperatures were investigated. The magnitudes of total aerobic bacteria In hamburger were highly detected to be in the order of resting placed in expressway > convenience stores > fast food stores, and coliforms were lowly detected as convenience stores > fast food stores > resting places in expressway. In investigation of basic ingredients, the degree of microorganic pollution showed highly on patty. cabbage and cucumber. In investigated result of mocroorganic distribution at the various phases in hamburger manufacturing, total aerobic bacteria counts were detected over 5.5$\times$10$^2$ CFU/g, and coliforms counts were detected over 2.0$\times$10$^2$ CFU/g. In investigated result of microorganic distribution on the instruments and equipments for hamburger manugacturing, total aerobic bacteria counts were detected over 10$\^$5/ CFU/100cm2 and coliforms counts were detected over 10$^2$CFU/100㎠. Staphylococcus aureus was detected at wagon and refrigerator. Salmonella spp. was detected at grinder and Vibrio parahaemolyticus was not detected. At various storage temperatures, total aerobic bacteria counts insreased 3.0$\times$10$^3$ CFU/g to 7.0$\times$10$^4$ CFU/g, 4.2$\times$10$\^$7/ CFU/g and 8.1$\times$10$\^$8/ CFU/g at 10$\^{C}$, 20$\^{C}$, 30$\^{C}$ after 48 hours respectively. coliform counts also increased 4.5$\times$10$^2$ CFU/g to 2.2$\times$10$^3$ CFU/g, 5.4$\times$10$\^$5/ CFU/g, 4.5$\times$10$\^$6/ CFU/g at 10$\^{C}$, 20$\^{C}$, 30$\^{C}$ after 48 hours respectively. The establishment of critical control point CCP was divided into CCP1 and CCP2 by the removing level of hazard factor, and then CCP1 was established on basic ingredients, and CCP2 was established on the phases of mixing, pouring, packaging, transporting and preserving.

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Fabrication and Electrical Properties of High Tc $A_{2}B_{2}O_{7}$ Piezoelectric Ceramics Using the Powders Prepared by the Chemical Coprecipitation Method (화학적공침법에 의한 $A_{2}B_{2}O_{7}$ 고온압전세라믹스의 제작과 전기적 특성)

  • Son, Chang-Heon;Jeon, Sang-Jae;Nam, Hyo-Duk
    • Journal of Sensor Science and Technology
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    • 제6권4호
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    • pp.316-327
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    • 1997
  • Polycrystalline $Sr_{2}Nb_{2}O_{7}$ and $La_{2}Ti_{2}O_{7}$ ceramics with very high Curie temperatures were synthesized by the chemical coprecipitation method (CCP). The powders synthesized were identified by XRD and their sintering behavior and physical properties were studied. The grain-orientation and electrical properties of sintered ceramics were investigated as a function of firing temperature. Single phase could be obtained by CCP method at temperature lower than that of the conventional method by 100 - $150^{\circ}C$. Strontium niobate, $Sr_{2}Nb_{2}O_{7}$, powder was Prepared by CCP method at temperatures as low as $800^{\circ}C$ via intermediate phase of $Sr_{5}Nb_{4}O_{15}$ formed at $700^{\circ}C$. The resulting CCP-derived powder was observed to have finer and more uniform particle size distribution than those obtained through the conventional or the molten salt synthesis method. Sintering of CCP-derived $Sr_{2}Nb_{2}O_{7}$ powder at $1500^{\circ}C$ yielded a highly dense ceramics with 97% theoretical density. Very high grain-orientation developed along the (0k0) direction was observed by SEM, which resulted in anisotropic dielectric properties of the sintered samples, with the dielectric constant values approaching those for single crystal.

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