• Title/Summary/Keyword: Electric field treatments

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Effect of Liquid Surface Treatments on Field Emission Properties of Carbon Nanotube Cathodes

  • Lee, Ji-Eon;An, Young-Je;Shin, Heon-Cheol;Chung, Won-Sub;Cho, Young-Rae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.486-489
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    • 2007
  • Carbon nanotube (CNT) cathodes having a trench structure similar to the structure of the gated triodetype cathode were successfully fabricated by a screenprinting method with multi-walled carbon nanotubes. We observed that a liquid method not only readily removes the organic residues on the CNT films, but also satisfactorily protrudes the CNTs out of the electrode surface. The CNT cathodes prepared by the liquid method showed a turned-on field of $1.4\;V/{\mu}m$. The emission current density of them was about $3.1\;mA/cm^2$ at the electric field of $3\; V/{\mu}m$. The liquid method appears to be a promising surface treatment of CNT cathode for gated triode-type FEDs applications.

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The Relaxation of Nonlinear Optical Properties in a Poled Polymer (극화된 고분자에서 비선형 광학특성의 완화)

  • Jung, Chi-Sup
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.6
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    • pp.491-496
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    • 2010
  • The relaxation behavior of aligned electric dipoles in a mixed polymer of P2ANS with P(VDF-TrFE) is studied with optical second harmonic generation (SHG). In this work, a macroscopic noncentrosymmetry of the spin coated film was achieved by an electrical poling. The relaxation of induced polar order of nonlinear optic(NLO) chromophores after poling leads to an insufficient long-term stability of NLO properties. In this work, we develop a new technique to suppress such kind of dipole relaxation in a poled polymer. We found that the poled dipoles in a NLO polymer were effectively immobilized by the internal electric field created by a thermally annealed ferroelectric polymer. The long-term stability in a mixed system of NLO polymer/ferroelectric polymer was successively accomplished by a series of thermal treatments applied to the mixed polymer system at a temperature of $140^{\circ}C$ for at least 1hour after poling.

Methods for improving meat protein digestibility in older adults

  • Seung Yun Lee;Ji Hyeop Kang;Da Young Lee;Jae Won Jeong;Jae Hyeon Kim;Sung Sil Moon;Sun Jin Hur
    • Journal of Animal Science and Technology
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    • v.65 no.1
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    • pp.32-56
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    • 2023
  • This review explores the factors that improve meat protein digestibility and applies the findings to the development of home meal replacements with improved protein digestion rates in older adults. Various methods improve the digestion rate of proteins, such as heat, ultrasound, high pressure, or pulse electric field. In addition, probiotics aid in protein digestion by improving the function of digestive organs and secreting enzymes. Plant-derived proteases, such as papain, bromelain, ficin, actinidin, or zingibain, can also improve the protein digestion rate; however, the digestion rate is dependent on the plant enzyme used and protein characteristics. Sous vide processing improves the rate and extent of protein digestibility, but the protein digestion rate decreases with increasing temperature and heating time. Ultrasound, high pressure, or pulsed electric field treatments degrade the protein structure and increase the proteolytic enzyme contact area to improve the protein digestion rate.

Physiological Changes of Saccharomyces cerevisiae by High Voltage Pulsed Electric Field Treatments (고전압 펄스 전기장 처리에 의한 Saccharomyces cerevisiae의 생리적 변화)

  • Park, Hee Ran;Yoon, So Jung;Park, Han-Sul;Shin, Jung-Kue
    • Korean Journal of Food Science and Technology
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    • v.45 no.5
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    • pp.590-597
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    • 2013
  • High voltage pulsed electric fields (PEF) treatment is a promising non-thermal processing technology that can replace or partially substitute for thermal processes. The aim of this research was to investigate the microbial inactivation mechanisms by PEF treatment in terms of physiological changes to Saccharomyces cerevisiae. PEF was applied at the electric field strength of 50 kV/cm, treatment time of 56 ${\mu}s$ and temperature of $40^{\circ}C$. The microbial cells treated with PEF showed loss of salt tolerance on the cell membrane and collapse of the relative pH gradient on in-out of cells. Cell death or injury resulted from the breakdown of homeostasis, decreased $H^+$-ATPase activity, and loss of glycolysis activity.

Effects of Cacti on the Protection against Low Frequency Electromagnetic Waves Radiated from Computer Monitor (컴퓨터 모니터 발생 전자파 차단에 미치는 선인장의 효과 유무)

  • Son, Ki-Cheol;Ryu, Myung-Hwa;Park, Woong-kyu
    • Horticultural Science & Technology
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    • v.17 no.6
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    • pp.773-776
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    • 1999
  • Effects of cacti and a few indoor plants on the protection of the harmful electromagnetic waves (ELF: extremely low frequency and VLF: very low frequency bands) radiated from the monitor of computer were investigated in indoor condition. The front screen of monitor evoked the highest amounts of electromagnetic waves as compared to other positions. Therefore, plants and other objects were placed on the front or side of monitor in order to measure electromagnetic waves. It was shown that all plants including cacti did not have any effect on the reduction of magnetic waves in both ELF and VLF, regardless of species and varieties, sizes, and dispositions. In the case of electric waves, however, there was a little reduction by cacti, depending upon several treatments mentioned before, but the measured values did not reach below values ruled by TCO (Tjatemannens Central Organization, Swedish Confederation of Professional Employees; electric field: 10 V/m and 1 V/m in ELF and VLF, respectively).

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Analysis of an External Stimulator's Impact on the Heart (체외 전기자극기가 심장에 미치는 영향의 분석 및 평가)

  • Kim, Mun-Soo;Choe, Seung-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.11
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    • pp.1213-1217
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    • 2011
  • Electric stimulators are used for various treatments, such as for pain relief and to improve rehabilitation in and out of the hospital. However, if the stimulation pulse affects the patient's heart, it can cause critical cardiac disorders such as arrhythmia or ventricular fibrillation. As a result, it must be ensured that the transmission length of the stimulation pulse does not exceed the proper range in the design of an electric stimulator. Furthermore, every anticipated risk factor must be monitored in in-vitro and in-vivo experiments. A new stimulator was designed to supply continuous 0.001 J stimulation pulses at a rate of 60 pulses per second. To evaluate the safety of the new electric stimulator and to measure its energy transfer and pulse transmission length, we built a conduction model that was filled with saline and measured the electric field at various positions in response to real stimulations. In an animal experiment with two pigs, heart disorders were induced by applying electric stimulation to tissues near the heart. These heart disorders were different from the result obtained with 9 V DC stimulation.

Effect of High Voltage Pulsed Electric Fields on Extraction of Purple Sweet Potato Pigment (자색 고구마 색소의 추출에 미치는 고전압 펄스 전기장의 영향)

  • Shin, Jung-Kue;Shin, Hae-Hun
    • Food Science and Preservation
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    • v.14 no.2
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    • pp.165-169
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    • 2007
  • High voltage pulsed electric fields (PEF) is a promising technology for the nonthermal extraction of effective components from biological materials. Plant cells were ruptured with PEF at ambient or refrigerated temperature for a short treatment time of second or microsecond. Treatments of coarsely ground purple sweet potato (PSP) with PEF(30 kV/cm, 500 Hz) resulted in maximum extraction yield of 65% as compared with 45-50% for control. An increase in electric field strength (from 10kV/cm to 35kV/cm) and frequency (from 100Hz to 500Hz) resulted in increased amount of extracted pigments, but treatment time is not affected on pigment extraction. Starch granules were not detected and large intracellular spaces were visible between the cells on light and scanning election microscopy of PEF treated PSP. This result suggests that PEF have potential to use on extraction of pigments from plant cells.

A Study on Safety Accidents at Construction Work Sites of Railway (철도 건설공사 현장의 안전사고에 관한 연구)

  • Bang, Myung-Seok;Choi, Soo-Hwan
    • Journal of the Korean Society of Safety
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    • v.25 no.5
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    • pp.33-38
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    • 2010
  • Railway is one of popular transportation systems. Due to the safety and in time, the transportation by train is preferred to the others for a long time. However, accidents under railway construction get more serious problems than in case of the other system, because it is the largest mass transportation system. Especially, the railway construction is composed of different kinds of construction works such as civil, architect, electric and mechanic. It is closely/complicatedly connected with various workers, large machines and facilities, regulations etc. In this study the data on safety accidents are corrected during 6 years(2004~2009) and analyzed by time(year, month, week, day, a.m or p.m), place, field, type etc. Results shows that there exists remakable trends on accidents, so efficient treatments should be prepared considering this trend.

Analysis of Soil Properties and Microbial Communities for Mine Soil Vegetation (폐광산지역 토양 식생복원 과정 내 토양특성 및 미생물 군집 변화 분석)

  • Park, Min-Jeong;Yoon, Min-Ho;Nam, In-Hyun
    • Journal of Soil and Groundwater Environment
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    • v.20 no.3
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    • pp.83-91
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    • 2015
  • Mine soil contamination by high levels of metal ions that prevents the successful vegetation poses a serious problem. In the study presented here, we used the microbial biocatalyst of urease producing bacterium Sporosarcina pasteurii or plant extract based BioNeutro-GEM (BNG) agent. The ability of the biocatalysts to bioremediate contaminated soil from abandoned mine was examined by solid-state composting vegetation under field conditions. Treatment of mine soil with the 2 biocatalysts for 5 months resulted in pH increase and electric conductivity reduction compared to untreated control. Further analyses revealed that the microbial catalysts also promoted the root and shoot growth to the untreated control during the vegetation treatments. After the Sporosarcina pasteurii or plant extract based BNG treatment, the microbial community change was monitored by culture-independent pyrosequencing. These results demonstrate that the microbial biocatalysts could potentially be used in the soil bioremediation from mine-impacted area.

Applications of Low-voltage Ohmic Process Combined with Temperature Control System to Enhance Salting Process of Pork

  • Hong, Geun-Pyo;Chun, Ji-Yeon;Choi, Mi-Jung
    • Food Science of Animal Resources
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    • v.32 no.3
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    • pp.293-300
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    • 2012
  • This study investigated the effects of a low-voltage ohmic heating process (2.5 and 3.8 V/cm) on the thawing characteristics and NaCl diffusion of pork. The thawing rate of pork was dependent on the applied voltages and brine salinities, and few differences were obtained in pork quality parameters (color, water-holding capacity, and shear force) regarding the different treatments. The NaCl concentration of pork after ohmic thawing was higher than that following brine-immersion thawing, however, the NaCl diffusion did not differ from when fresh meat was immersed in brine. For application of the ohmic process in fresh pork, various ohmic pulses were generated in order to prevent the meat from overheating, and the results indicated that the ohmic process was a better way to enhance NaCl diffusion compared with immersing pork at high temperature. Although the mechanisms involved in NaCl diffusion at low-voltage electric field strength were unclear, the present study demonstrated that the ohmic process has a potential benefit in the application of meat processing.