• Title/Summary/Keyword: Treatment field

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Enhanced Field Emission and Luminescent Properties of Straightened Carbon Nanotubes to be Applied in Field Emission Display

  • Lee, Hyeong-Rag;Kim, Do-Hyung;Kim, Chang-Duk;Jang, Hoon-Sik
    • Journal of Information Display
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    • v.4 no.2
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    • pp.35-42
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    • 2003
  • The field emission and luminescent properties of carbon nanotubes (CNTs) that were straightened by argon ion irradiation were investigated. Argon ion irradiation permanently straightened both as-grown and screen-printed CNTs (SP-CNTs) in the presence of a strong electric field. The straightening process enhanced the emission properties of as-grown CNT films by showing a decrease in turn-on field, an increase in total emission current, and a stable emission. Recurring problems associated with SP-CNTs, such as bent or/and buried CNTs and the degradation in binder-residue-induced emission, were improved by the permanent straightening of CNTs and protruding CNTs from binders by the irradiation treatment, in addition to its surface cleaning effect. Furthermore, we confirmed that the number of emission sites increases by observing the luminescent properties of CNT films after the straightening. These findings here suggest that ion irradiation treatment is an effective method for achieving uniform field emission and to reduce the electrical aging time.

Sewage Treatment Using Electric Field Pretreatment and Metal Membrane Microfiltration Process (전기장 전처리 및 금속 정밀여과 공정을 이용한 하수처리)

  • Jung, Jongtae;Kim, Jongoh
    • Journal of the Korean GEO-environmental Society
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    • v.8 no.5
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    • pp.15-21
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    • 2007
  • This study was investigated to evaluate the effect of electric fields application for the reduction of membrane fouling, the inactivation of microorganisms and the enhancement of particle coagulation in microfiltration/coagulation. Cumulative permeate in the case with electric field treatment showed high value compared to the case without electric field. Particularly, the increase of HRT (Hydraulic retention time) showed the increase of cumulative permeate as well as the decrease of total resistance. By electric field treatment, the amount of small particle size less than 100 ${\mu}m$ is increased and the survival fraction is reduced by the increase of electric field intensity. This may be attributed to the cleavage of particle or cytological destruction resulting from the inactivation of microorganism. Coagulant dosage of PAC compared with no electric field application could also be saved about 75% for the 95% of turbidity removal at 10 kV/cm.

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Treatment Planning Correction Using MRI in the Radiotherapy of Cervical Cancer (자궁 경부암의 방사선 치료계획에서 자기공명 영상을 이용한 조사야 교정)

  • Shin, Sei-One;Cho, Kil-Ho;Park, Chan-Won
    • Journal of Yeungnam Medical Science
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    • v.12 no.2
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    • pp.203-209
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    • 1995
  • Purpose: To evaluate the role of MRI in the management of cervical cancer treated by conventional four-field whole pelvic irradiation. Method and material: Between 1993-march and 1994-february, 20 patients(4 Stage I B, 3 Stage II A, 13 Stage II B) with invasive cervical cancer were eligible for evaluation of accuracy of conventionally designed lateral treatment field without MRI determination. Results: 5 out of 20 Patients had inadequate margin without MRI. The position of uterine fundus was more important than cervix in correction of field size and the center of treatment field. Conclusion: This Preliminary data show MRI determination of uterine position prior to radiotherapy planning is essential in the case of four-field whole pelvic irradiation technique.

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Inactivation of Escherichia coli, Saccharomyces cerevisiae, and Lactobacillus brevis in Low-fat Milk by Pulsed Electric Field Treatment: A Pilot-scale Study

  • Lee, Gun Joon;Han, Bok Kung;Choi, Hyuk Joon;Kang, Shin Ho;Baick, Seung Chun;Lee, Dong-Un
    • Food Science of Animal Resources
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    • v.35 no.6
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    • pp.800-806
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    • 2015
  • We investigated the effects of a pulsed electric field (PEF) treatment on microbial inactivation and the physical properties of low-fat milk. Milk inoculated with Escherichia coli, Saccharomyces cerevisiae, or Lactobacillus brevis was supplied to a pilot-scale PEF treatment system at a flow rate of 30 L/h. Pulses with an electric field strength of 10 kV/cm and a pulse width of 30 µs were applied to the milk with total pulse energies of 50-250 kJ/L achieved by varying the pulse frequency. The inactivation curves of the test microorganisms were biphasic with an initial lag phase (or shoulder) followed by a phase of rapid inactivation. PEF treatments with a total pulse energy of 200 kJ/L resulted in a 4.5-log reduction in E. coli, a 4.4-log reduction in L. brevis, and a 6.0-log reduction in S. cerevisiae. Total pulse energies of 200 and 250 kJ/L resulted in greater than 5-log reductions in microbial counts in stored PEF-treated milk, and the growth of surviving microorganisms was slow during storage for 15 d at 4℃. PEF treatment did not change milk physical properties such as pH, color, or particle-size distribution (p<0.05). These results indicate that a relatively low electric-field strength of 10 kV/cm can be used to pasteurize low-fat milk.

A mini-review on microplastics in drinking water treatment processes (정수처리장 내의 미세플라스틱의 유입 및 처리기술 현황에 관한 고찰)

  • Choi, Byeonggyu;Kim, Jiyoon;Choi, Soohoon
    • Journal of Korean Society of Water and Wastewater
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    • v.34 no.5
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    • pp.357-371
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    • 2020
  • Microplastics have become a rising issue in due to its detection in oceans, rivers, and tap water. Although a large number of studies have been conducted on the detection and quantification in various water bodies, the number of research conducted on the removal and treatment of microplastics are still comparatively low. In the current research, the inflow and removal of microplastics were investigated for various drinking water treatment plants around the world. Addition to the investigation of filed research, a survey was also conducted on the current research trend on microplastic removal for different treatment processes in the drinking water treatment plants. This includes the researches conducted on coagulation/flocculation, sedimentation, dissolved air flotation, sand filtration and disinfection processes. The survey indicated mechanisms of microplastic removal in each process followed by the removal characteristics under various conditions. Limitations of current researches were also mentioned, regarding the gap between the laboratory experimental conditions and field conditions of drinking water treatment plants. We hope that the current review will aid in the understanding of current research needs in the field of microplastic removal in drinking water treatment.

Impact of Herbicide Oxadiazon on Microbial Activity and Nitrogen Dynamics in Soil Environment

  • Rahman, Md. Mokhlesur;Song, Kyung-Sik;Rhee, In-Koo;Kim, Jang-Eok
    • Journal of Applied Biological Chemistry
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    • v.48 no.4
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    • pp.187-192
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    • 2005
  • Influence of herbicide oxadiazon on soil microbial activity and nitrogen dynamics was evaluated. Soil samples were treated with oxadiazon at field and tenfold field rates and incubated. Organic amendment was added as an additional substrate for soil microorganisms. Tenfold field rate oxadiazon stimulated substrate-induced respiration (SIR) and dehydrogenase activity (DHA) in amended soil as compared to unamended soil and control treatment. Soil urease activity was not affected by oxadiazon treatment. In both amended and unamended soils, treatment of the herbicide at higher rate had not significant influence on $NH_4$-N and $NO_3$-N concentrations. Higher dose of oxadiazon was degraded in both soils, but dissipation rate in amended soil was higher than unamended soil, with half-lives ($t_{1/2}$) of 23.1 and 138.6 days, respectively. Recommended field rate did not affect microbial activity and nitrogen dynamics in soil ecosystem. Results showed influence of oxadiazon on cycling processes of nitrogen in soil was not significant however its effect on microbial activity was a tendency depending on addition of organic amendment to soil.

Feasibility of Shrinking Field Radiation Therapy through 18F-FDG PET/CT after 40 Gy for Stage III Non-Small Cell Lung Cancers

  • Ding, Xiu-Ping;Zhang, Jian;Li, Bao-Sheng;Li, Hong-Sheng;Wang, Zhong-Tang;Yi, Yan;Sun, Hong-Fu;Wang, Dong-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.1
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    • pp.319-323
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    • 2012
  • Objective: To explore the feasibility of shrinking field technique after 40 Gy radiation through 18F-FDG PET/CT during treatment for patients with stage III non-small cell lung cancer (NSCLC). Methods: In 66 consecutive patients with local-advanced NSCLC, 18F-FDG PET/CT scanning was performed prior to treatment and repeated after 40 Gy. Conventionally fractionated IMRT or CRT plans to a median total dose of 66Gy (range, 60-78Gy) were generated. The target volumes were delineated in composite images of CT and PET. Plan 1 was designed for 40 Gy to the initial planning target volume (PTV) with a subsequent 20-28 Gy-boost to the shrunken PTV. Plan 2 was delivering the same dose to the initial PTV without shrinking field. Accumulated doses of normal tissues were calculated using deformable image registration during the treatment course. Results: The median GTV and PTV reduction were 35% and 30% after 40 Gy treatment. Target volume reduction was correlated with chemotherapy and sex. In plan 2, delivering the same dose to the initial PTV could have only been achieved in 10 (15.2%) patients. Significant differences (p<0.05) were observed regarding doses to the lung, spinal cord, esophagus and heart. Conclusions: Radiotherapy adaptive to tumor shrinkage determined by repeated 18F-FDG PET/CT after 40 Gy during treatment course might be feasible to spare more normal tissues, and has the potential to allow dose escalation and increased local control.

The effects of Bambusae Caulis and St. John's Wort in the chronic mild stress model of depression in rats (우울증(憂鬱症)모델 흰쥐에 대한 죽여(竹茹)와 St. John's Wort의 항우울효과(抗憂鬱效果)에 대한 비교 연구)

  • Park, Se-Jin;Kim, Jong-Woo;Kim, Hyun-Taek;Chi, Sang-Eun;Kim, Wonn-Ryoung;Hwang, Ui-Wan
    • Journal of Oriental Neuropsychiatry
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    • v.15 no.2
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    • pp.53-70
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    • 2004
  • Objective : This study was designed to assess the protective effects of Bambusae caulis and St. John's Wort on the animal model of depression, induced by chronic mild stress(CMS) Method : Male Wistar rats were used for this experiment. The subjects were divided into 4 groups ( 1. CMS-drugs: Bambusae caulis administered during CMS treatment, 2. CMS-drugs: St. John's Wort administered during CMS treatment, 3. CMS-vehicle: Water administered during CMS treatment, 4. normal control group without CMS treatment ). After 3 weeks of CMS treatment, they were executed open field test and weight, sucrose intake were measured. Result : 1. CMS Bambusae caulis group showed significant difference of locomotor activities and marginal difference of start latency in comparison with other groups in open field test. 2. There was no change of weights between CMS Bambusae caulis, St. John's Wort groups and CMS control group. 3. CMS St. John's Wort group showed upper level of sucrose intake than CMS Bambusae caulis group and CMS control group. Conclusion : These results suggest that Bambusae caulis may have protective antidepressant effects in CMS model rats. And these effects could be explained by the elevated locomotor activities in open field test.

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A Study of Real Time Verification System or Radiation Therapy (방사선치료 위치 실시간 검증시스템에 관한 연구)

  • Kim, Y.J.;Ji, Y.H.;Lee, D.H.;Lee, D.H.;Hong, S.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.164-167
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    • 1997
  • The treatment setup of patients during irradiation is an important aspect in relation to the success of radiotherapy. Imaging with the treatment beam is a widely used method or verification of the radiation field position relative to the target area, prior to or during irradiation. In this paper, Real time digital radiography system was implemented or verification of local error between simulation plan and radiation therapy machine. Portal image can be acquired by CCD camera, image board and pentium PC after therapy Radiation was converted into light by a metal/fluorescent Screen. The resulting image quality is comparable to film, so the imaging system represents a promising alternative to film as a method of verifying patient positioning in radiotherapy. Edge detection and field size measurement were also implemented and detected automatically for verification of treatment position. Field edge was added to the original image or checking the anatomical treatment verification by therapy technicians. By means of therapy efficiency improvement and decrease of Radiation side effects with these techniques, Exact Radiation treatments are expected.

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Comparison of Efficiency between Individual Randomization and Cluster Randomization in the Field Trial (지역사회 임상시험시 개인별 무작위배정과 군집 무작위배정의 효율성 비교)

  • Koo, Hye-Won;Kwak, Min-Jeong;Lee, Young-Jo;Park, Byung-Joo
    • Journal of Preventive Medicine and Public Health
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    • v.33 no.1
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    • pp.51-55
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    • 2000
  • Objectives . In large-scale field trials, randomization by cluster is frequently used because of the administrative convenience, a desire to reduce the effect of treatment contamination, and the need to avoid ethical issues that might of otherwise arise. Cluster randomization trials are experiments in which intact social unit, e.g., families, schools, cities, rather than independent individuals are randomly allocated to intervention groups. The positive correlation among responses of subjects from the same cluster is in matter in cluster randomization. This thesis is to compare the results of three randomization methods by standard error of estimator of treatment effect. Methods : We simulated cholesterol data varing the size of the cluster and the level of the correlation in clusters and analyzed the effect of cholesterol-lowering agent. Results : In intra-cluster randomization the standard error of the estimator of treatment effect is smallest relative to that in inter-cluster randomization and that in individual randomization. Conclusions : Infra-cluster randomization is the most efficient in its standard error of estimator of treatment effect but other factor should be considered when selecting a specific randomization method.

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