• Title/Summary/Keyword: Field treatment

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Enhancement of Field Emission Characteristics of CuO Nanowires Formed by Wet Chemical Process (습식공정으로 형성된 구리산화물 나노와이어의 전계방출특성 향상)

  • Sung Woo-Yong;Kim Wal-Jun;Lee Seung-Min;Lee Ho-Young;Park Kyung-Ho;Lee Soonil;Kim Yong-Hyup
    • Journal of the Korean institute of surface engineering
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    • v.37 no.6
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    • pp.313-318
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    • 2004
  • Vertically-aligned and uniformly-distributed CuO nanowires were formed on copper-coated Si substrates by wet chemical process, immersing them in a hot alkaline solution. The effects of hydrogen plasma treatment on the field emission characteristics of CuO nanowires were investigated. It was found that hydrogen plasma treatment enhanced the field emission properties of CuO nanowires by showing a decrease in turn-on voltage, and an increase in emission current density, and stability of current-voltage curves. However, the excessive hydrogen plasma treatment made the I-V curves unstable. It was confirmed by XPS (X-ray Photoelectron Spectroscopy) analysis that hydrogen plasma treatment deoxidized CuO nanowires, thereby the work function of the nanowires decreased from 4.35 eV (CuO) to 4.1 eV (Cu). It is thought that the decrease in the work function enhanced the field emission characteristics. It is well-known that the lower the work function, the better the field emission characteristics. The results suggest that the hydrogen plasma treatment is very effective in achieving enhanced field emission properties of the CuO nanowires, and there may exist an optimal hydrogen plasma treatment condition.

Strain Improvement of Yeast for Ethanol Production Using a Combined Treatment of Electric Field and Chemical Mutagen N-Methyl-N'-nitro-N- nitrosoguanidine

  • Kim, Keun;Lee, Jae-Yeon
    • Journal of Microbiology and Biotechnology
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    • v.8 no.2
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    • pp.119-123
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    • 1998
  • The feasibility of using combined treatments of electric field and chemical mutagen N-methyl-N'-nitro-N-nitroso-guanidine (NTG) for the strain improvement of Saccharomyces sp. in ethanol production was examined. The treatment of electric field alone resulted in no effect on the lethality of yeast cells under the conditions of this study. However, when the electric field was applied together to the treatment of yeast cells with NTG, the electric field increased the lethal effect and auxotrophic mutation rate of NTG. The combined treatment of electric field and NTG also increased the chances of. obtaining superior yeast strains for the ethanol production from tapioca. A higher number of improved clones was obtained by the combined treatments of electric field and NTG than by the NTG treatment alone. The best clone, NF 30-9, which was also obtained by the combined treatment, produced $11.07\%$ (w/v) ethanol from tapioca slurry containing 25% (w/v) reducing sugar while the parental strain produced 9.77% (w/v).

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Evaluation of the Dose According to the Movement of Breath During Field-in-Field Technique Treatment of Breast Cancer Patients (유방암 환자의 Field-in-Field Technique 치료 시 호흡의 움직임에 따른 선량 평가)

  • Kwon, Kyung-Tae
    • Journal of radiological science and technology
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    • v.41 no.6
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    • pp.561-566
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    • 2018
  • Field-in-Field Technique is applied to the radiation therapy of breast cancer patients, and it is possible to compensate the difference in breast thickness and deliver uniform dose in the breast. However, there are several fields in the treatment field that result in a more complex dose delivery than a single field dose delivery. If the patient's respiration is irregular during the delivery of the dose by several fields and the change of respiration occurs, the dose distribution in the breast changes. Therefore, based on the computed tomography images of breast cancer patients, a human model was created by using a 3D printer (Builder Extreme 1000) to describe the volume in the same manner. A computerized tomography (CT) of the human body model was performed and a treatment plan of 260 cGy / fx was established using a 6-MV field-in-field technique using a computerized treatment planning system (Eclipse 13.6, Varian, USA). The distribution of the dose in the breast according to the change of the respiration was measured using a moving phantom at 0.1 cm, 0.3 cm, 0.5 cm amplitude, using a MOSOXIDE Silicon Field Effect Transistor (MOSFET, Best Medical, Canada) Were measured and compared. The distribution of dose in the breast according to the change of respiration showed similar value within ${\pm}2%$ in the movement up to 0.3 cm compared to the treatment plan. In this experiment, we found that the dose distribution in the breast due to the change of respiration when the change of respiration was increased was not much different from the treatment plan.

A Study on Field Applicability Evaluation of the Hydrophobic - Low Viscosity Surface Treatment Material for Pavement Preventive Maintenance (소수성 특성을 이용한 저점도 AP 표면처리재의 현장 적용성 연구)

  • Choi, Jun Seong
    • International Journal of Highway Engineering
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    • v.16 no.1
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    • pp.31-39
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    • 2014
  • PURPOSES : Surface treatment material for pavement preventive maintenance should be inspected field applicability. This study(Part II) aimed to checkup coating characteristics and performance analysis using lab and field tests. The hydrophobic - low viscosity filling material for pavement preventive maintenance is presented in Part I, which is a series of companion study. METHODS : Relative comparison between general asphalt mixtures and surface treatment asphalt mixtures are analyzed and measured for the field application such as indirect tensile strength ratio(TSR), abrasion resistance, crack propagation resistance, temperature resistance, coating thickness, permeability resistance and skid resistance in terms of british pendulum number(BPN). RESULTS : It is found that TSR, crack propagation resistance and permeability resistance is increased as against uncoated asphalt specimen. Abrasion resistance and temperature resistance is secured from the initial coating thickness point of view, which is about 0.2~0.3mm. Skid resistance on the surface treatment pavement is satisfied with the BPN criteria of national highway because of exposed aggregate and crack sill induced pavement deterioration and damage cracks. CONCLUSIONS : The hydrophobic - low viscosity surface treatment material for pavement preventive maintenance is validated on field applicability evaluation based on quantitative analysis of coating thickness and performance analysis using lab and field tests.

Design and embodiment of variableness band style magnetic field nerve stimulation system that apply $1^{trigger}$ $2^{mode}$ magnetic field treatment Probe for disease treatment

  • Kim, Whi-Young;Park, Sung-Joon
    • Journal of information and communication convergence engineering
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    • v.6 no.4
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    • pp.411-416
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    • 2008
  • When compose magnetic field curer by belt and band style and need by magnetic field ripple last month, produce self-discipline roof. Bred in muscle disease (lumbago, backbone disease, corpulence) back. Result that study, manufactured various variableness band style - magnetic field probe firstly. Can establish self-discipline treatment pulse price by disease secondly. Could seek correct variableness band punishment, - magnetic field probe relationship implementation and property in waist, and so on, shoulder, neck, arm, leg, ankle, wrist etc. by third. Could find variableness band style energy value that need in-magnetic field Probe's treatment by fourth. This research could design pulse of self-discipline in band form and apply each according to disease.

Thermally Stimulated Current from High Density Polyethylene Treated by a High Field Application (고전계인가처리된 고밀도 폴리에티렌의 열자극전류)

  • 이덕출
    • 전기의세계
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    • v.27 no.3
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    • pp.31-35
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    • 1978
  • In this paper, in order to clarify the mature of traps in polymer, the thermally stimulated current (TSC) measurements were mad on high density polyethylene by changing the condition of the high-field treatment such as the strength of the field (Fe), the treatment time (te) and the heating rate (.betha.). In addition, the TSC measured from the HDPE was compared with that from LDPE having different crystallinity. The obtained results can suggest that the trapping proceeds during the high-field treatment and the trap associated with the peak P$_{2}$ may have the closed relation to drystallinity and the release of trapped charge is enhanced by the molecular motion.

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Surface States and Field Emission Properties of Oxygen Plasma Treated Carbon Nanotubes (산소 플라즈마 처리한 탄소나노튜브의 표면상태와 전계방출 특성)

  • Lee, Sunwoo;Lee, Boong-Joo;Park, Gu-Bum;Shin, Paik-Kyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.3
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    • pp.376-379
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    • 2013
  • Multi-walled carbon nanotubes (MWCNTs) were synthesized using catalytic chemical vapor deposition (CVD) method. Oxygen plasma treatment was applied to modify surface state of the CNTs synthesized for improvement of field emission performance. Surface state of the plasma treated CNTs was studied by X-ray photoelectron spectroscopy (XPS). The surface states of the CNTs were changed as a function of plasma treatment time. The oxygen related carbon shift was moved toward higher binding energy with the plasma treatment time. This result implies that the oxygen plasma treatment changes the surface state effectively. While any shift in carbon 1s peak was not detected for the as grown CNTs, oxygen related carbon shift was detected for the plasma treated CNTs. Carbon shift implies that closed CNT tips were opened by the oxygen plasma and reacted with oxygen species. Since the field emission occurs at pentagons or dangling bonds of the CNT tips, the increase of carbon-oxygen bonds plays an important role in field emission behavior by increasing the number of electron emission sites resulting in improvement of the field emission performance.

A comparative study of dose distribution for whole brain with field-in-field technique (전뇌(Whole Brain)치료 시 Field-in-Field Technique 적용에 관한 고찰)

  • Kim Bo Kyoum;Lee Je Hee;Jung Chi Hoon;Pack Heung Deuk
    • The Journal of Korean Society for Radiation Therapy
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    • v.17 no.1
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    • pp.9-17
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    • 2005
  • Purpose : Uniform dose distribution of the target volume is very important in the radiation treatment. We will evaluate the usefulness of Field-in-Field Technique use to get uniform dose distribution of the target volume and try to find Apply possibility out to a whole brain treatment patient of various thickness. Material and method : We compare the dose distribution when we applied Field-in-Field Technique and parallel opposed fields technique. establish the treatment plan to a phantom(acryl 16cm spheral phantom) and do the measurement, assessment use the TLD and Low sensitivity film. Also the assessment did Apply possibility of Field-in-Field Technique to 20 patient object of various thickness. Result : In the case to use the parallel opposed fields at the whole brain treatment $10-12\%$ high dose region appeared but reduce to $3-4\%$ lesses when we used the Field-in-Field technique. We could get similar numerical value the film and TLD measurement result also. The change of the dose distribution appeared to its ${\pm}1{\sim}2\%$ although it applied such Field-in-Field technique to various patient so that we were identical. Conclusion : We can get uniform dose distribution of in the treatment region if we apply the Field-in-Field technique at the whole brain treatment. Also alternate can play the role of the wedge filter and 3D compensator and We are thought by minimizing the obstacle to be happened due to the high dose region when radiation treatment.

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Research about design and manufacture of Crossing High-Amplitude Magneto-Therapy own nerve system for Muscuoskeltal tissue rehalibitation treatment (근조직 재활치료를 위한 자계신경 자극시스템의 설계 및 구현)

  • Kim, Whi-Young
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.855-856
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    • 2006
  • Magnetic nerve stimulation treatment is much backward real condition than other field. Specially, successful medical treatment introduction of magnetic field (MF) can was refered long ago in Avicenna's work, and is thought as age of medicine magnetology development recently. These development is achieved through biologist and biophysicist and clinician's joint effort, but, new mountings and relationship air tassel are developed steadily. Magnetic nerve stimulation treatment field designs treatment system by each function during long wave high-amplitude (traditional magneto therapy of greatly great that strong that) short time that CMF, VMF, PMF field etc. are representative but are HPMT technology in this research and manufacture and special quality did comparative analysis.

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A Study on the Disinfection of Coliform Group in the Effluent of Sewage Plant by High Voltage Electric Field Treatment (고전압 전기장을 이용한 하수처리장 방류수 중의 대장균군 소독에 관한 연구)

  • Lee, Min-Gyu;Chung, Geun-Sik;Kam, Sang-Kyu
    • Journal of Environmental Science International
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    • v.17 no.7
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    • pp.817-826
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    • 2008
  • Using high voltage electric fields induced by high voltage AC (10-12 kV/cm, 20 kHz) and pulsed (20-30 kV/cm, 40 Hz) electric field generator as a semipermanent and environment-friendly disinfecting apparatus, the disinfection effect of coliform group in the effluent of sewage plant was investigated. The effects of electric field strength, treatment time, discharge area of a discharge tube, water quality factors (electric conductivity, pH and SS) on its death rate were examined. The death rate of coliform group was increased with increasing electric field strength and treatment time. For AC and pulsed electric field generator, the critical electric field strength was 6 kV/cm and 2 kV/cm, respectively, and the critical treatment time was 5 min and 2 min, respectively, regardless of electric field strength. Comparing the death rate of coliform group by AC and pulsed electric fields used in this study, its death rate was higher for the latter than the former, but did not increase linearly with increasing electric field strength. The results obtained for the effects of discharge area, electric conductivity, pH and SS on the death rate of coliform group using AC electric field (12 kV/cm, 20 kHz) were as follows: its death rate showed the trend to increase linearly with increasing discharge area; for the effect of electric conductivity, its death rate was increased with increasing electric conductivity, regardless of ionic species, increased with increasing cationic valency, but was similar between the same cationic valency; the pH $5{\sim}9$ used in this study did not affect its death rate; its death rate was decreased with increasing SS concentration.