• 제목/요약/키워드: Pulsed

검색결과 2,880건 처리시간 0.043초

Pulsed UV 처리수에서의 자연유기물질, 잔류염소 및 소독부산물 생성 거동 (Behavior of Natural Organic Matter(NOM), Chlorine Residual, and Disinfection By-Products(DBPs) Formation in Pulsed UV Treated Water)

  • 손진식;한지희
    • 상하수도학회지
    • /
    • 제26권5호
    • /
    • pp.685-692
    • /
    • 2012
  • UV technology is widely used in water and wastewater treatment. Many researches have been conducted on microbial disinfection and micro pollutant reduction with UV treatment. However, the study on NOM with UV has limited because low/medium pressure UV lamp is not sufficient to affect refractory organics such as NOM. Pulsed UV treatment using UV flash lamp can be operated in the pulsed mode with much greater peak intensity. The pulse duration is typically in microseconds, whereas the interval between pulses is in the order of milliseconds. The high intensity of pulsed UV would mineralize NOM itself as well as change the characteristics of NOM. Chlorine demand and DBPs formation is affected on the changed amounts and properties of NOM. The objective of this study is to investigate the effect on NOM, chlorine residual, and chlorinated DBPs formation with pulsed UV treatment.

펄스 직류 $CF_4$/ Ar 플라즈마 발생 장치의 전기적 특성 평가

  • 김진우;최경훈;박동균;송효섭;조관식;이제원
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
    • /
    • pp.236-236
    • /
    • 2011
  • 본 연구 축전 결합형 고주파 플라즈마(CCP) 식각장비에 펄스 직류(Pulse DC) 전원을 인가하여 오실로스코프(oscilloscope)를 분석하여 전기적 특성을 평가하는 것이다. 펄스 직류전원 플라즈마 시스템에서는 다양한 변수를 이해하여야 한다. 본 실험에서 사용한 공정 변수는 Pulsed DC Voltage 300~500 V, Pulsed DC reverse time $0.5{\sim}2.0{\mu}s$, Pulsed DC Frequency 100~250 kHz 이었다. 실험 결과를 정리하면 1) Pulsed DC Voltage 가 증가할수록 Input voltage의 최대값은 336~520 V, 최소값은 -544~-920 V로 변하여 피크 투 피크 (peak to peak)값은 880~1460 V로 증가였다. Input current 또한 최대값은 1.88~2.88 A, 최소값은 -0.84~-1.28 A로 변하여 피크 투피크 값은 2.88~4.24 A로 증가하였다. 이는 척에 인가되는 전류와 파워의 증가를 의미한다. 2) Pulsed DC reverse time이 증가하면 Input voltage와 Input current값이 증가했다 (Input voltage의 피크 투 피크 값은 1200~1440 V, Input current의 피크 투 피크 값은 3.56~4.56 A). 3) Pulsed DC frequency가 증가하면 주기가 짧아져 Input voltage와 Input current값이 증가 한다 (Input voltage의 피크 투 피크 값은 900~1320 V, Input current의 피크 투 피크 값은 2.36~3.64 A). 결론적으로 펄스 직류 플라즈마의 다양한 전기적 변수들은 반응기 내부에 인가되는 Input voltage와 Input current의 값에 큰 영향을 준다는 것을 알 수 있었다.

  • PDF

맥동전자장이 불완전 척수손상 흰쥐의 기능회복과 GAP-43의 발현에 미치는 영향 (The Effects of Pulsed Electromagnetic Field on Functional Recovery and Expression of GAP-43 after Incomplete Spinal Cord Injury in Rats)

  • 방현수
    • 대한물리의학회지
    • /
    • 제7권3호
    • /
    • pp.349-356
    • /
    • 2012
  • Purpose : This study was designed to investigate the effects of pulsed electromagnetic field on functional recovery and expression of GAP-43 after incomplete spinal cord injury (SCI) in rats. Methods : To confirm the damage of SCI and effects of pulsed electromagnetic field, 20 Sprague-Dawley male rats were used and divided randomly 2groups (SCI, PEMF). Incomplete SCI was induced by using modified NYU drop model. After operation, functional recovery test, immunohistochemistry and western blot analysis were measured at 1, 2, 3 weeks. Pulsed electromagnetic field were apply three weeks (one times a day, five days a week and twenty minutes a session). Results : In the this study, applications of pulsed electromagnetic field after incomplete SCI induced the significant improvement in functional recovery and expression of neurotrophic factor. The results were as follows; Foot print test, PEMF were significantly decreased than the SCI (p<.05). Expression of GAP-43, PEMF were significantly increased than the SCI at 2 and 3 weeks (p<.05). Conclusion : In conclusion, pulsed electromagnetic field were positive effect in functional recovery and expression of GAP-43 after incomplete SCI in rats.

Barrier Layers and Pulsed Laser Annealing Effects on TFEL Device with Cu and Ag co-doped SrS blue Phosphor Layer

  • Nam, Tae-Sung;Liew, Shan-Chun;Koutsogeorgis, Demosthenes C;Cranton, Wayne M
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
    • /
    • pp.910-913
    • /
    • 2003
  • In order to enhance performance, stability, and brightness of inorganic blue-light emitting EL device, barrier layer structure and pulsed laser annealing(PLA) treatment were introduced. The barrier layer structure was utilized for improving brightness of the device and instead of thermal annealing, pulsed laser annealing process was used. From this study, optimum barrier layer thickness and number of pulsed laser irradiation are established.

  • PDF

고전압.대전류 pulsed power의 이용기술 (Application Technologies of Pulsed Power with the High Voltage and Current)

  • 이형호;김영배
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1997년도 하계학술대회 논문집 E
    • /
    • pp.1678-1680
    • /
    • 1997
  • The pulsed power with the high voltage and current can be used to the fields of high speed pulses of energy in different forms such as electric current and voltage, electron beam, ion beam, x-rays, gamma rays, heat, magnetics fields, sound and shock waves. This paper is directed mainly at electrical engineers working on production and practical application of high speed pulsed power with high voltage and current.

  • PDF

A Simulation Study of a Chopping System for Extracting a Pulsed Beam from a Cyclotron

  • 김재홍;홍성광;김미정;김성준;김명진;김도균;윤종철;김종원
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
    • /
    • pp.537-537
    • /
    • 2013
  • Cyclotron-accelerated ion beams are used for various researches, such as nuclear physics, nuclear chemistry, biotechnology, and material sciences including radio-isotope production. Recently considerable applications are asked to the cyclotron development undertaken to meet user requirements of various ions'energies, intensities, and their pulsed beams. For instance, a cocktail beam acceleration technique rapidly changing the ion species and energies was developed to irradiating integrated circuit chips. Also a chopping system in a cyclotron injection line is considered for producing a pulsed ion beam with a relatively long period compared with that generated by the resonance frequency. For the research in neutron time-of-flight measurement, a single-pulsed beam with a repetition interval of the order of mili-seconds or longer is necessary to have a good resolution and to remove background events. In this paper a feasibility of pulsed beam with an external ion source is simulated by adopting a combination system of a chopper accompanying with a bunching stage in the injection line and an additional chopper after the exit of the cyclotron in order to produce beam pulses with a range of $1{\mu}s{\sim}1ms$ periods from a resonance RF cycle. The pulseperiod will be adjusted by chopping the number of beam bunches from the injected pulses in the injection line. However, the longer pulses will have reduced number of beam pulses and sacrificed beam currents. Because the beam users need an intense single pulsed beam, a careful tuning of the acceleration phase and a high-intense external ion source are necessary to achieve an intense single-pulsed beam from the cyclotron. It is essential to strictly match the acceleration phase of injected beams in the central region of the cyclotron to improve its efficiency. An effect of space charge at each pulse from the ion source will be also considered.

  • PDF

요추부 신경근통 환자에서의 박동성 고주파술의 치료 효과 (Therapeutic Efficacy of Pulsed Radiofrequency Treatment in Lumbar Radicular Pain)

  • 김영기;정일;한상희
    • The Korean Journal of Pain
    • /
    • 제21권3호
    • /
    • pp.202-205
    • /
    • 2008
  • Background: Lumbar radicular pain is a frequent and often debilitating event. Although many treatment methods have been described in several studies, the available evidences regarding efficacy is not sufficient enough to draw definitive conclusions on an optimal therapy regime. Pulsed radiofrequency (RF) treatment was found to exert a beneficial effect on intractable radicular pain in individuals. The purpose of this study was to assess the efficacy of pulsed RF of the dorsal root ganglion for chronic lumbar radicular pain. Methods: Twenty five patients with chronic lumbar radicular pain that was refractory to selective nerve root blockage met the inclusion criteria of our study and received pulsed RF treatment. The average numeric rating scale (NRS) for leg pain during usual activities and the Oswestry disability index (ODI) were measured at 1 and 3 months after the procedure. Results: Of the 25 patients accepted for pulsed RF treatment, one dropped out due to a vertebral compression fracture during this study. ODI and NRS showed a positive trend in favor of the pulsed RF treatment. No significant complications were observed during the study period. Conclusions: It appears that pulsed RF treatment of the lumbar spinal dorsal root ganglion may be an effective treatment method for patients suffering from lumbar radicular pain, and who were not responsive to selective nerve root blockage.

맥동전자장이 고지혈증 흰쥐의 혈액 성분, 항산화 효소 및 활성 산소에 미치는 영향 (The Effects of Pulsed Electromagnetic Fields on Blood components, Antioxidant enzymes and Reactive Oxygen in Hyperlipidemic Rats)

  • 방현수;정인호;이상덕
    • 디지털융복합연구
    • /
    • 제12권7호
    • /
    • pp.349-356
    • /
    • 2014
  • 본 연구는 맥동전자장이 고지혈증 관련 혈액 성분, 항산화 효소와 활성 산소에 어떠한 영향을 미치는 지를 관찰하기 위하여 실시하였다. 실험군은 정상식이군, 고지방식이군과 고지방식이-맥동전자장 적용군의 3군으로 나누었다. 맥동 전자장은 맥동 전자장 에너지 치료기를 이용하였다. 혈액 성분의 검사 항목은 혈당, 유리지방산, 중성지방 및 콜레스테롤, 인슐린이고, 항산화 효소와 활성 산소의 검사는 글루타치온, 글루타치온 환원효소, 크산틴, 과산화지질을 측정하였다. 그 결과 맥동전자장 적용은 혈액 구성성분과 GSH와 GRD를 고지장식이 수준에서 정상식이 수준으로 상승시켰으며, XO와 MDA는 고지방식이 수준에서 정상 식이 수준으로 낮추어 주는 개선효과를 나타내었다. 그러므로 맥동전자장의 적용은 고지혈증 흰쥐의 혈액성분의 변화, 항산화 효소의 증가, 활성 산화의 억제에 효과적인 치료 방법이라 할 수 있다.

백서에서 Pulsed Nd : YAG Laser에 의한 치은절제술후의 치유양상 (Wound Healing After Gingivectomy Using Pulsed Nd : YAG Laser In The Rat)

  • 김옥수;정현주
    • Journal of Periodontal and Implant Science
    • /
    • 제26권1호
    • /
    • pp.293-308
    • /
    • 1996
  • Recently, dental laser have been applied for removal of soft tissues, hemostasis and blood coagulation, removal of benign and malignant tumor, treatment of leukoplakia, aphthous ulcer and herpetic lesion, implant second surgery, removal of granulation tissue, frenectomy, clinical crown lengthening, gingivectomy, gingivoplasty, and treatment of dentin hypersensitivity. Even though the frequency of laser treatment is increasing, the research on the healing process after gingivectomy using pulsed Nd : YAG laser is very rare. The purpose of this study was to observe and compare the wound healing after gingivectomy using scalpel and pulsed Nd : YAG laser in the rat. Gingivectomy was performed using pulsed Nd : YAG laser(SUNRISE Technologies, U.S.A., 1.5 Watts, 10 pps) on the buccal gingiva of right maxillary first molar and using scalpel(No.12) on the contralateral side. Those sites treated by surgical scalpel were designated as the control, and by pulsed Nd : YAG laser as the experimental group. Animals were sacrificed at 1, 2, 3, 5, 7, 11 and 14 days postoperatively, and specimens were histologically observed under light microscope. The results were as follows : 1. Clinical observation Normal color and shape were observed at the 5th day ill the control group and the 7th day in the experimental group. 2. Histologic findings 1) In the control group, denser inflammatory infiltration was observed. 2) Epithelialization started at the 2nd day in the control group, similar to the experimental group, and completed at the 11th to the 14th day postoperatively. 3) In the experimental group, connective tissue showed the vacuole formation and degenerative change during early healing period. Healing of connective tissue was slower in the experimental group than in the control group by 2 days. 4) In the both groups, wound healing was completed at the 2nd week. From this study, gingivectomy using pulsed Nd : YAG laser seems to result in a little delayed wound healing process, compared to the gingivectomy using scalpel. Considering the clinical advantages of laser surgery, pulsed Nd : YAG laser might be useful device for gingivectomy.

  • PDF