• Title/Summary/Keyword: Field treatment

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Enhancement of Dewaterability of Sewage Sludge by Ultrasonification and Electric Field Treatment (초음파와 전기장 처리에 의한 하수슬러지 탈수성 향상)

  • Mo, Woojong;Han, Jisun;Ahn, Changmin;Yoon, Soonuk;Seok, Heejung;Kim, Changgyun
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.1
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    • pp.23-30
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    • 2013
  • The sludge disposal is a major economic factor in the sewage treatment facility operation. Moreover, since the ocean dumping will be prohibited by Korean environmental law from 2013, sludge should be eliminated or sludge volumetric reduction should be performed urgently. In this study, improvement of the sewage sludge dewaterability was investigated by ultrasound and electric field treatment. Sludge was treated by a single or in combination of either the electric field or ultrasound on a pilot pretreatment facility, then it was dewatered by lab-scale filter press. The operating input energy of ultrasound device was varied from 225~1,200 kJ/L and electric field device was varied from 4.5~24 kJ/L. The water contents of dewatered sludge cake treated with ultrasound (1,200 kJ/L) and combination of ultrasound/electric field (1,224 kJ/L) were decreased 10~12% by comparing non-treated sludge. At that time, water contents were 65~66%. The combination treatment of ultrasound/electric field was effective to reduce water content of dewatered sludge cake, however, water content was not changed by a single treatment of electric field because of low energy density.

Effects of Carbon Nitride Surface Layers and Thermal Treatment on Field-Emission and Long-Term Stability of Carbon Nanotube Micro-Tips (질화탄소 표면층 및 열처리가 탄소 나노튜브 미세팁의 전계방출 및 장시간 안정성에 미치는 영향)

  • Noh, Young-Rok;Kim, Jong-Pil;Park, Jin-Seok
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.1
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    • pp.41-47
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    • 2010
  • The effects of thermal treatment on CNTs, which were coated with a-$CN_x$ thin film, were investigated and related to variations of chemical bonding and morphologies of CNTs and also properties of field emission induced by thermal treatment. CNTs were directly grown on nano-sized conical-type tungsten tips via the inductively coupled plasma-chemical vapor deposition (ICP-CVD) system, and a-$CN_x$ films were coated on the CNTs using an RF magnetron sputtering system. Thermal treatment on a-$CN_x$ coated CNT-emitters was performed using a rapid thermal annealing (RTA) system by varying temperature ($300-700^{\circ}C$). Morphologies and microstructures of a-$CN_x$/CNTs hetero-structured emitters were analyzed by FESEM and HRTEM. Chemical composition and atomic bonding structures were analyzed by EDX, Raman spectroscopy, and XPS. The field emission properties of the a-$CN_x$/CNTs hetero-structured emitters were measured using a high vacuum (below $10^{-7}$ Torr) field-emission measurement system. For characterization of emission stability, the fluctuation and degradation of the emission current were monitored in terms of operation time. The results were compared with a-$CN_x$ coated CNT-emitters that were not thermally heated as well as with the conventional non-coated CNT-emitters.

Software Development and Clinical Application of a Multileaf Collimator on Linear Accelerator (치료용 가속기에 대한 Multileaf Collimator의 소프트웨어 개발 및 임상적용)

  • Chung, Kap-Soo
    • Journal of radiological science and technology
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    • v.22 no.1
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    • pp.61-66
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    • 1999
  • The use of multileaf collimator(MLC) to replace conventional field-shaping techniques is not in itself expected to improve the local control of malignancy. The purpose for using MLCs in conventional radiation oncology is to improve the efficiency of treatment delivery. For effective clinical application of MLCs to shaped radiation field, field outline must be translated into MLC leaf position tables. The intended leaf positions contained in these tables must then be communicated to the control computer that drives the MLC. There are currently at least three techniques utilized by manufacturers of MLCs and treatment planning systems for doing this. The Varian series use a workstation employing a manual digitizer and light box especially. It has a third level MLC configuration and also has the option of placing the wedges above or below the block tray. The C language are used for development of software and three leaf coverage have been used for positioning MLC loaves at the nominal field boundary. The fit of the leaf shape to treatment target volumes are optimized by the rotation of the direction in leaf travel. The clinical application of this software are investigated for Varian MLCs used in linear accelerator of Yonsei Cancer Center. The advantage of the results with using this software is to prescribe and calculate exposed and blocked area in MLCs field.

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Field Emission Properties of Screen Printed Carbon Nanotubes (스크린 프린팅된 탄소나노튜브의 전계방출 특성)

  • Lee, Yang-Doo;Lee, Jung-Ah;Moon, Seung-Il;Park, Jeung-Hoon;Han, Jong-Hun;Yoo, Jae-Eun;Lee, Yun-Hi;Nahm, Sahn;Ju, Byeong-Kwon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.5
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    • pp.541-544
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    • 2004
  • Multi- wall carbon nanotubes(MWNTs) were synthesized by thermal chemical vapor deposition. The paste for screen printing was composed of MWNTs, organic vehicle and glass frit. Carton nanotube paste was screen-printed on ITO(indium tin oxide) deposited soda lim을 glass, and then heat treatment was performed. Before the surface treatment, turn on field of derive was 2.6 V/$\mu\textrm{m}$. After the surface treatment, the value was changed into 1.8 V/$\mu\textrm{m}$. The anode current of the derive with 2.83 V/$\mu\textrm{m}$(turn on field) was changed 4 $\mu\textrm{A}$ into 390 $\mu\textrm{A}$ at 1,700 V. Adsorption effect of MWNTs onto phosphor of anode plate was observed by the field emission measurement and resulted in bad effects on properties of devices lifetime and emission lighting.

Biological Waste Water Treatment with Solar Thermal Energy (저온 태양열 이용 생물학적 오수 처리)

  • Chung, Mo;Lee, Dong-Won;Kim, Jeong-Bae;Yoon, Eung-Sang;Byun, Moo-Ryong;Byun, Moon-Won
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.559-562
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    • 2006
  • A low-temperature solar thermal system assisting a biological nitrogen treatment reservoir was designed and field-tested. A large tank whose temperature was maintained at about $25{\sim}30^{\circ}C$ to enhance the performance of a biological nitrogen treatment process was heated by an array of flat plate solar collectors. Test results revealed that the overall collector efficiency was above 50% for the most cases tested. This high efficiency was possible owing to the relatively low collector temperature that can be traced back to the reservoir temperature. A substantial enhancement in nitrogen treatment was observed as a result of maintaining the reservoir temperature higher.

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A Fluctuation of Soil Microflora in Upland Soil Treated with Metalaxyl, Carbofuran and Simazine (Metalaxyl, Carbofuran, Simazine을 처리한 밭토양에서의 미생물수의 변동)

  • Lee, Wang-Hyu;Kim, Ju-Hee
    • Korean Journal of Environmental Agriculture
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    • v.17 no.3
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    • pp.220-226
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    • 1998
  • The effects of metalaxyl(granule), carbofuran(granule) and simazine(water soluble powder) on the soil microflora were conducted at field soil between Iksan and Chonju province. Pesticides were divided into 0.5, 1, 1.5 and 2.0 times of normal of field, respectively. The number of fluorescent Pseudomonas was ranged from $10^3$ to $10^6/g$ in both field soil treated with cabofuran. Pseudomonas concentration of Chonju field soil slowly increased and approached the maximum level at 56 day after treatment(DAT). It showed the higher at 14DAT than other DAT in Iksan field soil treated with metalaxyl or simazine, whereas it increased again at 112 DAT in metalaxyl treatment. Cabofuran treatment of both field soil showed maximum Pseudomonas number at 28 DAT compared to that of other treatments. In Chonju field soil, those Pseudomonads of metalaxyl and simazine treatment increased the highest level at 7 DAT. Simazine treatment decreased it's number from the beginning of experiment. In both soil, metalaxyl treatment decrease the general fungi number at 7 DAT, but increase at 14 and 56 DAT in Iksan field soil. However it increased at 56 DAT in Chonju field soil. Cabofuran treatment of Iksan field soil tended to decrease general fungi number at 28 DAT, but was ranged from 1.0 to $8.6{\times}104/g$ for the rest of experimental period. It started to increase at 56 DAT simazine treatment of Iksan. General bacterial concentration both soil treated with cabofuran was belong to $26.6{\sim}29.6{\times}106$. It was the highest at 56 DAT, but was not significantly different. General actinomyces number was highly increased at 7 and 112 DAT compared to that of other DAT. Pseudomonas putida or P. fluorescens from both field soil was separated and identified 10 to 30 of all 104 Pseudomonas, respectively. All isolated microorganisms showed chemical resistance of 100ppm metalaxyl, cabofuran and simazine treatment.

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A Case of Combined Korean Medicine Treatment for Homonymous Hemianopia and Prosopagnosia after Ischemic Stroke (동측 반맹과 안면실인증을 호소하는 뇌경색 환자 한방복합치료 1례)

  • Kim, Geun Young;Park, Hojung;Lee, Yu Jin;Cho, Ki-Ho;Moon, Sang-Kwan;Jung, Woo-Sang;Kwon, Seungwon;Jin, Chul
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.22 no.1
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    • pp.21-30
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    • 2021
  • ■ Background Patients with posterior cerebral artery infarction could complain of visual field defects or prosopagnosia that does not recognize a person's face. However, there has been no standardized treatment for these symptoms. ■ Case report A 57-year-old male patient complained homonymous hemianopia and prosopagnosia after posterior cerebral artery infarction. After combined Korean medicine treatment for 49 days, subjective visual field was improved and the discomfort associated with visual field defect and the disability of recognizing people was decreased. Evaluations were took place by assessing visual field using Automated Perimetry and Confrontation visual field exam. Discomfort caused by visual field defects or prosopagnosia was evaluated by visual analog scale. The patient was treated with acupuncture, moxibustion, and herbal medications. ■ Conclusion The present case report suggests that combined Korean medicine treatment might be effective to resolution of homonymous hemianopia and prosopagnosia after stroke.

Improved Surface Morphologies of Printed Carbon Nanotubes by Heat Treatment and Their Field Emission Properties

  • Lee, Hyeon-Jae;Lee, Yang-Doo;Cho, Woo-Sung;Kim, Jai-Kyeong;Lee, Yun-Hi;Hwang, Sung-Woo;Ju, Byeong-Kwon
    • Journal of Information Display
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    • v.7 no.2
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    • pp.22-25
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    • 2006
  • This paper presents heating process for obtaining standing carbon nanotube emitters to improve field-emission properties from the screen-printed multiwalled carbon nanotube (MWCNT) films. In an atmosphere with optimum combination of nitrogen and air for heat treatment of CNT films, the CNT emitters can be made to protrude from the surface. This allows for high emission current and the formation of very uniform emission sites without special surface treatment. The morphological change of the CNT film by this technique has eliminated additional processing steps, such as surface treatment which may result in secondary contamination and damage to the film. Despite its simplicity the process provides high reproducibility in emission current density which makes the films suitable for practical applications.

Field Experiments of Scientific Conservation Treatment for Bangudae Petroglyphs in Ulsan, South Korea (울산반구대암각화 보존처리를 위한 현장적용실험)

  • Lee, Tae-jong;Oh, Jung-hyeon;Kim, Sa-dug
    • 보존과학연구
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    • s.33
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    • pp.69-83
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    • 2012
  • Field experiments for Conservation damage on selected spots were carried out prior to direct conservation treatments for Bangudae Petroglyphs in Ulsan. It was found that there is a big difference in treatment effects according to the treatment technique and application rather than on the treatment material use. Based on the results of this study, a plan for the conservation treatment of Bangudae Petroglyphs will be suggested by providing new materials and application techniques for cracks, adhesive application and consolidation by conducting artificial weathering tests and continued monitoring.

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Effects of Pulsed Electric Field on Meat Tenderization and Microbial Decontamination: A Review

  • Se-Ho Jeong;Han-Beak Lee;Dong-Un Lee
    • Food Science of Animal Resources
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    • v.44 no.2
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    • pp.239-254
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    • 2024
  • This review sought to categorize studies on meat tenderization and safety through pulsed electric field (PEF) treatment, with a particular focus on reconciling conflicting findings regarding the tenderization effect (i.e., the primary outcome of PEF treatment) and to discuss the underlying mechanisms of these effects. While the tenderization effect may vary depending on the homogeneity of PEF treatment and variations in the conditions of texture measurements, the protein associated with tenderization was degraded by PEF treatment in most studies. PEF technology enables the delivery of a high voltage for a brief duration, typically in the microsecond range, making it a non-thermal technology. One of the distinct advantages of PEF is its ability to preserve the freshness of meat due to its exceptionally short treatment time. While PEF studies have traditionally centered on pasteurizing liquid foods, research on its application to meat is steadily expanding. Therefore, this review aims to elucidate the mechanisms of PEF and provide current insights into the applications of this technology for meat tenderization and microbial inactivation.