• Title/Summary/Keyword: External Dose

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Application of the Detection of External Contamination on Radiation Workers for Bed Type Whole Body Counting Using Monte Carlo Method (몬테카를로 방법을 적용한 bed type 전신계측기의 방사선작업종사자 외부오염 검출 응용)

  • Kim, Jeong-In;Lee, Byoung-Il
    • Journal of Radiation Protection and Research
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    • v.38 no.4
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    • pp.242-245
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    • 2013
  • Monte Carlo method was applied to discriminate the external contamination on radiation workers in nuclear power plants for internal dose assessment generally used with a bed type scanning detector whole body counter. Korean voxel model with internal contamination was used to estimate the detection patterns of whole body scanning. Also, the BOMAB model with various external contamination was assumed to compare with detection of radionuclides inside the human body. From the comparison of detection efficiency between front and back side up, external contamination was easily distinguished.

Evaluation Absorbed Dose During the Breast Cancer Brachytherapy in Canine Phantom (반려견 팬텀에서 유방암 근접방사선치료 시 흡수선량 평가)

  • Kim, Jung-Hoon;Lee, Deuk-Hee
    • Journal of the Korean Society of Radiology
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    • v.14 no.5
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    • pp.523-528
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    • 2020
  • The application of breast cancer, which has the highest incidence in females among cancer that is the number one cause of death for dogs, was to be evaluated the absorbed dose during brachytherapy using simulation. MCNPX program was used for simulation, and a small size canine phantom was produced to measure absorbed dose. The results of the absorbed dose was the highest at 192Ir to 1.02E-12 Gy/# for tumors, and the same tendency was shown for internal and external absorbed dose. Therefore, the selection of appropriate sources for dog breast cancer should be considered in brachytherapy, taking into account dog breeds and exposures.

In vitro Antimicrobial Effects of Silver Nanoparticles on Microorganisms Isolated from Dog with Otitis External

  • Bae, Seul-gi;Yun, Sung-ho;Oh, Tae-ho
    • Journal of Veterinary Clinics
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    • v.34 no.6
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    • pp.425-428
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    • 2017
  • Silver nanoparticles have marked antimicrobial effects on several pathogens and have been used to control bacterial growth in humans. In the present study, we evaluated the antimicrobial efficacy of silver nanoparticles against the common causative pathogens of canine otitis external through counting of colony forming units. Silver nanoparticles showed significant dose-dependent antimicrobial effects on pathogens. In addition, we conducted antimicrobial susceptibility tests and compared the antimicrobial efficacy of silver nanoparticles. Microorganisms with a high resistance to antibiotics were also resistant silver nanoparticle with low concentration ($5{\mu}g/mL$). However, in high concentration ($15{\mu}g/mL$), almost 100% reduction in the number of CFUs of these pathogens was observed.

Percutaneous Tunnel Ventriculostomy for the Hydrocephalus Complicated with Ventriculitis - Case Report - (뇌실염이 합병된 수두증환자에서 피하터널 조루술 - 증례보고 -)

  • Hwang, Sung-Nam;Cho, Jae-Young;Park, Seung-Won;Kim, Young-Baeg;Choi, Duck-Young
    • Journal of Korean Neurosurgical Society
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    • v.30 no.7
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    • pp.939-942
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    • 2001
  • Thirty nine-year-old man who required urgent shunt operation due to rapidly deteriorating visual acuity suffered from ventriculitis after aneurysmal operation. Daily dose of 20mg of vancomycin and amikyn were given intraventricularly via external ventricular catheter after failure of various kinds of systemic antibiotics. The exit of the catheter was made on the upper chest wall to prevent superinfection. External ventricular drainage could finally be switched to ventriculo-peritoneal shunt and he was discharged with clinical improvement.

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Single Dose Topical Application of Clotrimazole for the Treatment of Otomycosis: Is This Enough?

  • Dundar, Riza;Iynen, Ismail
    • Korean Journal of Audiology
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    • v.23 no.1
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    • pp.15-19
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    • 2019
  • Background and Objectives: To determine the efficacy of filling the external auditory meatus with 1% clotrimazole at a single visit for the treatment of otomycosis. Subjects and Methods: This prospective study included 40 patients who were referred to our clinic with complaints of ear itching, pain, and fullness, and were diagnosed with unilateral otomycosis. After cleaning the mycotic hyphae from the external auditory meatus, the ear canal was filled with 1% clotrimazole, using an intravenous catheter and syringe. The patients received follow-up examinations on post-treatment days 7, 15, and 45. Results: The follow-up otomicroscopic examinations revealed that 95% of the ear canals were entirely clean and that all symptoms had resolved. The post-treatment scores of pain, aural fullness and itching were significantly lower than the pre-treatment scores (p<0.01). Conclusions: Filling the external auditory meatus with 1% clotrimazole at a single visit is an easy, efficient, and cost-effective treatment for otomycosis. Additionally, high patient compliance makes this treatment superior to long-term topical therapy.

Single Dose Topical Application of Clotrimazole for the Treatment of Otomycosis: Is This Enough?

  • Dundar, Riza;Iynen, Ismail
    • Journal of Audiology & Otology
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    • v.23 no.1
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    • pp.15-19
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    • 2019
  • Background and Objectives: To determine the efficacy of filling the external auditory meatus with 1% clotrimazole at a single visit for the treatment of otomycosis. Subjects and Methods: This prospective study included 40 patients who were referred to our clinic with complaints of ear itching, pain, and fullness, and were diagnosed with unilateral otomycosis. After cleaning the mycotic hyphae from the external auditory meatus, the ear canal was filled with 1% clotrimazole, using an intravenous catheter and syringe. The patients received follow-up examinations on post-treatment days 7, 15, and 45. Results: The follow-up otomicroscopic examinations revealed that 95% of the ear canals were entirely clean and that all symptoms had resolved. The post-treatment scores of pain, aural fullness and itching were significantly lower than the pre-treatment scores (p<0.01). Conclusions: Filling the external auditory meatus with 1% clotrimazole at a single visit is an easy, efficient, and cost-effective treatment for otomycosis. Additionally, high patient compliance makes this treatment superior to long-term topical therapy.

Analysis of Domestic and Overseas Radioactive Waste Maritime Transportation and Dose Assessment for the Public by Sinking Accident (국내·외 방사성폐기물 해상운반 현황 및 침몰사고 시 일반인 선량평가 사례 분석)

  • Ga Eun Oh;Min Woo Kwak;Hyeok Jae Kim;Kwang Pyo Kim
    • Journal of Radiation Industry
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    • v.18 no.1
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    • pp.35-42
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    • 2024
  • Demand for RW transportation is expected to increase due to the continuous generation of RW from nuclear power plants and facilities, decommissioning of plants, and saturation of spent fuel temporary storage facilities. The locational aspect of plants and radiation protection optimization for the public have led to an increasing demand for maritime transportation, necessitating to apprehend the overseas and domestic current status. Given the potential long-term radiological impact on the public in the event of a sinking accident, a pre-transportation exposure assessment is necessary. The objective of this study is to investigate the overseas and domestic RW maritime transportation current status and overseas dose assessment cases for the public in sinking accident. Selected countries, including Japan, UK, Sweden, and Korea, were examined for transport cases, Japan and the U.S were chosen for dose assessment case in sinking accidents. As a result of the maritime transportation case analysis, it was performed between nuclear power plants and reprocessing facilities, from plants to disposal or intermediate storage facilities. HLW and MOX fuel were transported using INF 3 shipments, and all transports were performed low speed of 13 kn or less. As a result of the dose assessment for the public in sinking accident, japan conducted an assessment for the sinking of spent fuel and vitrified HLW, and the U.S conducted for the sinking of spent fuel. Both countries considered external exposure through swimming and working at seashore, and internal exposure through seafood ingestion as exposure pathway. Additionally, Japan considered external exposure through working on board and fishing, and the U.S considered internal exposure through spray inhalation and desalinized water and salt ingestion. Internal exposure through seafood ingestion had the largest dose contribution. The average public exposure dose was 20 years after the sinking, 0.04 mSv yr-1 for spent fuel and 5 years after the sinking, 0.03 mSv yr-1 for vitrified HLW in Japan. In the U.S, it was 1.81 mSv yr-1 5 years after the sinking of spent fuel. The results of this study will be used as fundamental data for maritime transportation of domestic RW in the future.

Region-wise evaluation of gamma-ray exposure dose in decontamination operation after a nuclear accident

  • Jeong, Hae Sun;Hwang, Won Tae;Han, Moon Hee;Kim, Eun Han;Lee, Jo Eun;Lee, Cheol Woo
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2652-2660
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    • 2021
  • The gamma-ray exposure doses in decontamination operation after a nuclear accident were evaluated with a consideration of various geometrical conditions and specific gamma-ray energies. The calculation domain is organized with three residence types and each form is divided into two kinds of geometrical arrangements. The position-wise air KERMA values were calculated with an assumption of evenly distributed gamma-ray source based on Monte Carlo radiation transport analysis using the MCNP code. The radioactivity is initially set to be unity to be multiplied by the deposition value measured in the actual accident condition. The workforce data set depending on the target object was determined by modifying the Fukushima report. The external exposure doses for decontamination workers were derived from the calculated KERMA values and the workforce analysis. These results can be used to efficiently determine the workforce required by the characteristics of the area and the structure to be decontaminated within the dose limits.

Simulating the impact of iodine as a contrast substance to enhance radiation to the tumor in a brain x-rayphototherapy

  • M. Orabi
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1671-1676
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    • 2023
  • The influence of adding iodine as a contrast substance to elevate radiation in a tumor is studied using simulation techniques of Monte-Carlo. The study is carried on a brain cancer by adopting an unsophisticated head phantom. The ionizing radiation source is an external beam of x-rays with energy range of a few tens of keV. The expected radiation dose increment due to adding the iodine is investigated by comparing the radiation in the tumor after and before adding the iodine and calculating the ratio between the two doses. Several concentrations of the contrast substance are used to quantify its impact. The change of the dose increment with the source energy is also examined. It is found that the radiation elevation in the tumor tends to saturate with increasing the iodine concentration, and for the studied domain of energies (30 keV-100 keV), the radiation dose enhancement factors (RDEF) for the different iodine concentrations (1%-9%) show peaked curves, with the peak occurring between 60 keV and 70 keV. For the highest concentration studied, 9%, the peak value is almost 7.

Implications of using a 50-μm-thick skin target layer in skin dose coefficient calculation for photons, protons, and helium ions

  • Yeom, Yeon Soo;Nguyen, Thang Tat;Choi, Chansoo;Han, Min Cheol;Lee, Hanjin;Han, Haegin;Kim, Chan Hyeong
    • Nuclear Engineering and Technology
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    • v.49 no.7
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    • pp.1495-1504
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    • 2017
  • In a previous study, a set of polygon-mesh (PM)-based skin models including a $50-{\mu}m-thick$ radiosensitive target layer were constructed and used to calculate skin dose coefficients (DCs) for idealized external beams of electrons. The results showed that the calculated skin DCs were significantly different from the International Commission on Radiological Protection (ICRP) Publication 116 skin DCs calculated using voxel-type ICRP reference phantoms that do not include the thin target layer. The difference was as large as 7,700 times for electron energies less than 1 MeV, which raises a significant issue that should be addressed subsequently. In the present study, therefore, as an extension of the initial, previous study, skin DCs for three other particles (photons, protons, and helium ions) were calculated by using the PM-based skin models and the calculated values were compared with the ICRP-116 skin DCs. The analysis of our results showed that for the photon exposures, the calculated values were generally in good agreement with the ICRP-116 values. For the charged particles, by contrast, there was a significant difference between the PM-model-calculated skin DCs and the ICRP-116 values. Specifically, the ICRP-116 skin DCs were smaller than those calculated by the PM models-which is to say that they were under-estimated-by up to ~16 times for both protons and helium ions. These differences in skin dose also significantly affected the calculation of the effective dose (E) values, which is reasonable, considering that the skin dose is the major factor determining effective dose calculation for charged particles. The results of the current study generally show that the ICRP-116 DCs for skin dose and effective dose are not reliable for charged particles.