• 제목/요약/키워드: Beam or Direct Radiation

검색결과 18건 처리시간 0.027초

Removal of EDCs from Industrial Sludge by Electron Beam

  • Han, Bumsoo;Kim, Jinkyu;Kim, Yuri;Jung, Seungtae;Park, Junhyung;Choi, Jangseung
    • 방사선산업학회지
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    • 제8권2호
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    • pp.71-76
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    • 2014
  • Endocrine disrupting chemicals (EDCs) and potential EDCs are mostly man-made, found in various materials such as pesticides, additives or contaminants in food, and personal care products. The high energy ionizing radiation has the ability to remove the EDCs with a very high degree of reliability and in a clean and efficient manner. The ionizing radiation interacts with EDCs both directly and indirectly. Direct interaction takes place with EDCs and the structure of EDCs is destroyed or changed. During indirect interaction, radiolysis products of water result in the formation of highly reactive intermediates which then react with the target molecules, culminating in structural changes. To confirm the radiation reduction of EDCs in industrial sludge, a pilot scale experiment up to 50 kGy of electron beam (EB) was conducted with samples from the textile dyeing industries. The experimental result showed the over 90% of reduction of Nonylphenol (NP) and Di(2-ethylhexyl) phthalate (DEHP) at around 10 kGy of absorbed doses.

국내 직달일사량 자원의 평가 연구 (An Evaluation Study of Domestic Direct(Beam) Nomal Solar Radiation Data)

  • 조덕기;이태규;김은일;전일수;이순명;조서현;오정무
    • 태양에너지
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    • 제13권1호
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    • pp.59-66
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    • 1993
  • 1990년 12월부터 전국 주요 16개지역에 측정네트�p을 구성하고, 직달일사량 자료를 수집하였다. 측정 된 자료를 토대로 지역별 표준치 설정하여 이들 자료를 집광식시스템의 설계자와 관련 연구자들에게 광범위하게 이용될 수 있도록 제시하였다. 현지 측정사업의 내용을 중심으로 지금까지의 결과를 살펴보면, 1) 우리나라의 법선면 직달일사조건은 청명한 날을 기준으로 하루에 $4,400kcal/m^2$내외이다. 2) 연평균치에 대한 계절별 일사조건은 봄과 여름이 각각 6%, 14% 높았으며, 가을과 겨울은 5%, 15% 정도 상대적으로 낮았다.

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새로운 전중추신경 방사선 조사법 ; 방사선속의 발산에 의한 선량의 불균일성을 극복하기 위한 치료 방법 (A New Technique for Whole Craniospinal Irradiation (WCSI))

  • 장혜숙
    • Radiation Oncology Journal
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    • 제9권1호
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    • pp.159-164
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    • 1991
  • 전중추신경 방사선 조사는 수아세포종, 중추신경정상피종, 중추신경임파종, 중추신경백혈병 환자 치료에 시행한다. 뇌부위에는 양면 조사야를 통하고 척추 신경부위는 후면 단일 조사야를 통해 방사선 조사한다. 이때 조사야가 인접한 부위에서 발생하는 방사선조사야의 중첩에 의한 선량의 불균일성은 큰 문제로, 특히 척추신경의 극히 한정된 방사선 인내능력으로 인해 심각한 부작용을 병발할 수 있다. 이 문제를 해결하기위한 많은 연구가 보고되고 있으나 그들이 보고한 방법에 의해서도 불균일성은 최고 $60\%\sim70\%$로 부터 최소 $15\%\sim20\%$에 이른다. 저자는 split beam (central axis beam)과 collimator rotation technique을 이용하거나 collimator/couch rotation technique을 이용하여 3조사야가 접하는 부위의 방사선량의 불균일성을 해결하고자 시도하였다. 저자의 방법으로 시행할 때 3조사야가 접하는 부위에서의 불균일성은 $5\%$정도로 감소시킬 수 있었다. 본 논문에서 저자의 방법의 장단점을 기술하였다.

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국내 태양열시스템 설치를 위한 성분일사량 분석 (Analysis of Solar Radiation Components for the Installation of Solar Thermal System in Korea)

  • 조덕기;강용혁
    • 한국태양에너지학회 논문집
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    • 제29권3호
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    • pp.12-18
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    • 2009
  • The Knowledge of the solar radiation components are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high thermodynamic efficiency achievable only at the higher temperatures. In order to estimate the performance of concentrating thermal systems, it is necessary to know the intensity of the beam radiation, as only this component can be concentrated. The Korea Institute of Energy Research(KIER) has began collecting solar radiation component data since January, 2002. KIER's component data will be extensively used by concentrating system users or designers as well as by research institutes. The theoretical analysis of solar radiation as a component has compared with the experimental data obtained by the KIER station. The Result of simulation analysis shows that the annual-average daily diffuse radiation on the horizontal surface is $1,457cal/m^2$ and daily direct radiation on the horizontal surface is $1,632cal/m^2$ for all over the 16 areas in Korea.

국내 일사량의 성분 분석 (Analysis of Solar Radiation Components in Korea)

  • 조덕기;윤창열;김광득;강용혁
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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    • pp.8-12
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    • 2009
  • The Knowledge of the solar radiation components are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high thermodynamic efficiency achievable only at the higher temperatures. In order to estimate the performance of concentrating thermal systems, it is necessary to know the intensity of the beam radiation, as only this component can be concentrated. The Korea Institute of Energy Research(KIER) has began collecting solar radiation component data since August, 2002. KIER's component data will be extensively used by concentrating system users or designers as well as by research institutes. The Result of analysis shows that the annual-average daily diffuse radiation on the horizontal surface is $1,458cal/m^2$ and daily direct radiation on the horizontal surface is $1,632cal/m^2$ for all over the 16 areas in Korea.

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일사량의 성분 분석에 관한 연구 (A Study on the Analysis of Solar Radiation Components)

  • 조덕기;전일수;이태규;강용혁;오정문
    • 한국태양에너지학회 논문집
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    • 제21권1호
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    • pp.43-49
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    • 2001
  • Informations of the solar radiation component are essential for modeling various solar energy systems. These Informations are particularly used for middle and high temperature applications, those need concentrating direct normal insolation. In order to estimate the performance of concentrating systems, it is necessary to know the intensity of the beam radiation, as only this component can be concentrated. The Korea Institute of Energy Research(KIER) has began collecting solar radiation component data since August, 1996. KIER's component data will be extensively used by concentrating system users or designers as well as by research institutes.

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Screening of Radio-resistant Lactic Acid Bacteria

  • Hwang, E-Nam;Kang, Sang-Mo;Kim, Jae-Kyung;Lee, Ju-Woon;Park, Jong-Heum
    • 한국축산식품학회지
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    • 제33권3호
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    • pp.335-340
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    • 2013
  • This study screened for radio-resistant strains lactic acid bacteria (LAB) by evaluating their capability to survive exposure to ionizing radiation. Ten strains of LAB - Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus delbruekii, Lactococcus lactis, Streptococcus thermophilus, Bifidobacterium breve, and Pediocuccos pentosaceus - were selected and subcultuted twice. The LAB was then further cultured for 3 d at $37^{\circ}C$ to reach 7-10 Log colony-forming units (CFU)/mL prior to irradiation and immediately exposed to gamma rays or electron beams with absorbed doses of 0, 1, 2, 3, 4, 5, 6, 8, and 10 kGy. Gamma irradiation gradually decreased the number of the tested viable LAB, and the effect was irradiation dose dependent. A similar effect was found in electron beam-irradiated LAB. Radiation sensitivity of LAB was calculated as $D_{10}$ values, which ranged from 0.26 kGy to 0.9 kGy and 0.5 kGy to 1.44 kGy with exposure to gamma and electron beam irradiation, respectively, in all tested LAB. L. acidophilus was the most resistant to gamma and electron beam irradiation, with $D_{10}$ values of 0.9 kGy and 1.44 kGy, respectively. These results suggest that L. acidophilus might be suitable for the preparation of probiotics as direct-fed microbes for astronauts in extreme space environments.

Dexmedetomidine for Repeated Sedation in Pediatric Sedation During Consecutive Radiation Therapy

  • Kim, Eun-Jung;Baek, Seung-Hoon;Byeon, Gyeong-Jo;Woo, Mi-Na
    • 대한치과마취과학회지
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    • 제14권4호
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    • pp.221-225
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    • 2014
  • External beam radiotherapy (EBRT) causes anxiety and claustrophobia in pediatric patients. To provide exact figures and radiation amounts, an appropriate sedation or anesthesia can be supplied. Alpha 2 agonist dexmedetomidine has been used for sedation and anesthesia in pediatric imaging. Dexmedetomidine has an advantage because it has minimal respiratory depression and no direct effects on myocardial function. We report repeated sedation with dexmedetomidine for 33 consecutive radiation therapies in 5 years old children.

마우스모델을 이용한 고속중성자선의 성장지연 및 산소증강비의 측정 (Measurement of Growth Delay and the Oxygen Enhancement Ratio of Fast Neutron Beam Using Mouse Model System)

  • 엄근용;박혜진;권은경;예성준;이동한;우홍균
    • Journal of Radiation Protection and Research
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    • 제32권4호
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    • pp.178-183
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    • 2007
  • 중성자선은 고 LET (linear energy transfer) 방사선으로 X선이나 감마선 등의 저 LET 방사선보다 세포에 더욱 큰 손상을 입힌다. 중성자에 의한 손상은 일반적으로 세포에 있어서 치명적이며, 중성자선은 X선이나 감마선에 비하여 직접작용을 통하여 세포사를 일으키는 경향이 있다. 본 연구에서는 고속중성자선의 성장지연비 및 산소증강비를 동물실험을 통하여 측정하고자 하였다. BALB-c 마우스의 우측 하지에 EMT-6 세포주를 이식한 후 종양의 평균용적이 $200-300mm^3$가 되었을 때 X선 및 고속중성자선을 조사하였다. 정상산소환경 및 저산소환경의 종양에 대하여 X선은 0, 11, 15.4 Gy를 조사하였고 고속중성자선은 0, 5, 7, Gy를 조사하였다. 방사선조사 후에는 종양의 용적을 주 3회 측정하였다. 정상산소환경 실험군의 경우 저산소환경 실험군에 비하여 X선 11 Gy를 조사하였을 때 성장지연비가 1.34였고, 15.4 Gy를 조사하였을 때 1.33였다. 고속중성자선을 조사한 경우정상산소환경 실험군이 저산소환경 실험군에 비하여 고속중성자선 5 Gy를 조사하였을 때 성장지연비는 0.94였고, 고속중성자선 7 Gy를 조사하였을 때 0.98였다. 고속중성자선의 산소증강비는 0.97이었다. 고속중성자선은 X선에 비하여 저산소환경에 있는 종양의 성장억제에 있어서 보다 효과적이었다.

Prognostic analysis of uterine cervical cancer treated with postoperative radiotherapy: importance of positive or close parametrial resection margin

  • Kim, Yi-Jun;Lee, Kyung-Ja;Park, Kyung Ran;Kim, Jiyoung;Jung, Wonguen;Lee, Rena;Kim, Seung Cheol;Moon, Hye Sung;Ju, Woong;Kim, Yun Hwan;Lee, Jihae
    • Radiation Oncology Journal
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    • 제33권2호
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    • pp.109-116
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    • 2015
  • Purpose: To analyze prognostic factors for locoregional recurrence (LRR), distant metastasis (DM), and overall survival (OS) in cervical cancer patients who underwent radical hysterectomy followed by postoperative radiotherapy (PORT) in a single institute. Materials and Methods: Clinicopathologic data of 135 patients with clinical stage IA2 to IIA2 cervical cancer treated with PORT from 2001 to 2012 were reviewed, retrospectively. Postoperative parametrial resection margin (PRM) and vaginal resection margin (VRM) were investigated separately. The median treatment dosage of external beam radiotherapy (EBRT) to the whole pelvis was 50.4 Gy in 1.8 Gy/fraction. High-dose-rate vaginal brachytherapy after EBRT was given to patients with positive or close VRMs. Concurrent platinum-based chemoradiotherapy (CCRT) was administered to 73 patients with positive resection margin, lymph node (LN) metastasis, or direct extension of parametrium. Kaplan-Meier method and log-rank test were used for analyzing LRR, DM, and OS; Cox regression was applied to analyze prognostic factors. Results: The 5-year disease-free survival was 79% and 5-year OS was 91%. In univariate analysis, positive or close PRM, LN metastasis, direct extension of parametrium, lymphovascular invasion, histology of adenocarcinoma, and chemotherapy were related with more DM and poor OS. In multivariate analysis, PRM and LN metastasis remained independent prognostic factors for OS. Conclusion: PORT after radical hysterectomy in uterine cervical cancer showed excellent OS in this study. Positive or close PRM after radical hysterectomy in uterine cervical cancer correlates with poor prognosis even with CCRT. Therefore, additional treatments to improve local control such as radiation boosting need to be considered.