• Title/Summary/Keyword: Background Radiation

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Analysis of University Student Awareness of Radiation Exposures from Consumer Products

  • Kim, SeungHwan;Cho, Kunwoo
    • Journal of Radiation Protection and Research
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    • v.41 no.1
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    • pp.57-70
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    • 2016
  • Background: Since the terminology 'radioactive consumer product' is not quite familiar to the public and is often considered as negative and detrimental things, the educational curriculum is essential for establishing reliability of nuclear energy related and for the development of better communication strategy of radiation risk with the public. To provide base data which is valuable for establishing efficient curriculum of education and training about radiation safety, it is necessary to apprehend the different level of awareness of radiation exposures classified by various consumer products. Materials and Methods: On November 2014, a question investigation about asking awareness level of radiation exposure from various consumer products was done for university students who are highly educated. The object students are studied at a four-year-course universities which is located at Daejeon City. Results and Discussion: Although the average awareness level is comparatively low, the awareness of senior students, who major in radiation, nuclear related departments and male students are relatively high. On the other hand, the awareness of freshman, sophomore, junior students, who do not major in radiation, nuclear related departments and female students are relatively low. It is necessary to provide various information to avoid unnecessary concerns and misconceptions about radiation exposure. Conclusion: This paper will be an instrument for efficient establishment of curriculum of education and training related with radiation safety.

Induction Chemotherapy Plus Radiation Compared with Surgery Plus Radiation in Patients with Advanced Laryngeal and Hypopharyngeal Cancer (진행된 후두암과 하인두암의 환자에서 유도화학 요법 후 방사선 치료와 수술 후 방사선 치료의 성적 비교 및 고찰)

  • Keum Ki Chang;Lee Chang Geol;Kim Gwi Eon;Lee Kyung Hee
    • Radiation Oncology Journal
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    • v.11 no.2
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    • pp.277-283
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    • 1993
  • Background: We peformed a retroslective study in patients with previously untreated advanced (Stage III or IV) laryngeal and hypopharyngeal cancer to compare the results of induction chemotherapy followed by definitive radiation therapy (CT+ RT) with those of conventional laryngectomy and postoperative radiation therapy (OP + RT). Method: Between 1985 and 1990, twenty-four patients were treated with two or three courses of chemotherapy and radiation therapy (66-75 Gy). Twenty-five patients were received laryngectomy and radical neck dissection (except 3 patients) and postoperative radiation therapy (55~64 Gy). Result: After a median fellow-up of 20 months, the actusrial 5-year overall survival rate was $24\%$ (chemotherapy group) and $36\%,$ (op group). (P>0.1). The local control rate was the $65\%,$ (13/20) and $68.2\%,$ (15/22). (p>0.1). The rate of laryngeal preservation was $65\%$ (13/20) in chemotherapy group. Conclusion: Induction chemotherapy and definitive radiation therapy can be effective in preserving the larynx in a high percentage of patients with advanced laryngeal and hypopharyngeal cancer.

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Prediction of the Apparent Temperature of an Object under the Infrared Waveband (적외선 파장대에서의 물체의 겉보기온도 예측)

  • Jung, Jinsoo;Kauh, S. Ken;Yoo, Hoseon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.3
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    • pp.352-363
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    • 1999
  • Target detection by the infrared imager depends on the apparent temperature difference between the target and the background, so it is essential to predict apparent temperature variations for this purpose. In this study, thermal analysis program Including conduction, convection and radiation is developed and applied to a representative geometry adequate for examining the apparent temperature characteristics. The results show that the longwave emissivity in association with the background temperature affects the apparent temperature strongly but does not affect the physical temperature. It is revealed that the background temperature plays a role of tuning the apparent temperature. As the longwave emissivity decreases, the apparent temperature decreases when the target is hotter than the background, whereas it increases in the reversed situation. These findings imply that an effective surface treatment, such as painting of a less emissive material, may provide a less detection probability and contribute to preventing the target from being detected at night.

The Effects of Nanoparticles for Irradiation (방사선조사에서 나노 입자 혼합물의 영향)

  • Yea, Ji-Woon;Shin, Hyun-Jin
    • Journal of Yeungnam Medical Science
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    • v.28 no.2
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    • pp.145-152
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    • 2011
  • Background: To evaluate the changes in the radiation dose and temperature distribution on irradiated egg albumin and nanoparticle ($Fe_3O_4$) powder mixed egg albumin. Methods: A new type of phantom was designed by fabricating a $30{\times}30{\times}30cm$ acryl square inside a $3{\times}3{\times}3cm$ small square and dividing it into two parts. In the control group, only egg albumin was irradiated, and in the test group, 25 nm 20 mg/cc, 25 nm 40 mg/cc, and 1 um 40mg/cc nanoparticles with egg albumin were irradiated. The radiation isodose distributions and temperature changes were then observed. Results: No significant changes were observed in the radiation dose and temperature distribution. Conclusion: The nanoparticles were considered not to have had any effect on the radiation dose and temperature distribution under the experimental conditions. Further studies can be conducted based on the changes in the mixture material.

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Effects of Millimetric Shifts in Breast Cancer Radiotherapy on the Radiation Dose Distribution

  • Sanli, Yusuf Tolga;Cukurcayir, Funda;Abacigil, Fatma
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1197-1199
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    • 2016
  • Background: This study aimed to facilitate decision-making in cases of breast cancer radiotherapy shifts by simulating millimetric shifts and analyzing their effects on dose distribution. Methods: The study included 30 patients with left side breast cancer who were treated with three dimensional conformal radiotherapy (3D-CRT) in the Radiation Oncology Department in Hatay Public Hospital, between January 2013 and April 2015. A treatment plan shifting at three axes with six different measures was simulated. Results: The biggest difference in values was (+3mm shift) 476cGy, with a 7.7 % change for heart and 25.6% for spinal cord. The shifts in values respectively for CTV min, mean, max were -4.8%, 2.5%, 4%. The differences for lymphatic min, mean, max were 21.3%, 20.3%, -12.2%. Conclusion: The most important thing is not the treatment plan quality, but its practicality. The treatment plan must be practical and its practice must be controlled rigidly.

A Review of Organ Dose Calculation Tools for Patients Undergoing Computed Tomography Scans

  • Lee, Choonsik
    • Journal of Radiation Protection and Research
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    • v.46 no.4
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    • pp.151-159
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    • 2021
  • Background: Computed tomography (CT) is one of the crucial diagnostic tools in modern medicine. However, careful monitoring of radiation dose for CT patients is essential since the procedure involves ionizing radiation, a known carcinogen. Materials and Methods: The most desirable CT dose descriptor for risk analysis is the organ absorbed dose. A variety of CT organ dose calculators currently available were reviewed in this article. Results and Discussion: Key common elements included in CT dose calculators were discussed and compared, such as computational human phantoms, CT scanner models, organ dose database, effective dose calculation methods, tube current modulation modeling, and user interface platforms. Conclusion: It is envisioned that more research needs to be conducted to more accurately map CT coverage on computational human phantoms, to automatically segment organs and tissues for patient-specific dose calculations, and to accurately estimate radiation dose in the cone beam computed tomography process during image-guided radiation therapy.

Star Detectability Analysis of Daytime Star Sensor (주간 활용 별센서의 별 감지가능성 분석)

  • Nah, Ja-Kyoung;Yi, Yu;Kim, Yong-Ha
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.9
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    • pp.89-96
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    • 2005
  • This paper discusses the daytime atmospheric conditions and the possibility of daytime star detection with the purpose of practical use of the star sensor for daylight navigation. In order to estimate the daytime atmospheric data, we use the standard atmospheric model (LOWTRAN 7), from which atmospheric transmittance and radiance from background sky are calculated. Assuming the star sensor with an optical filter to reduce background radiation, different separation angles between the star sensor and the sun are set up to express the effect of the solar radiation. As considerations of field of view (FOV) of the star sensor, the variation of the sky background radiation and the star density of the detectable star are analyzed. In addition, the integration time to achieve a required signal-to-noise ratio and the number of the radiation-caused electrons of the charge coupled detector(CCD) working as the limit to daylight application of the star sensor are calculated.

A Discussion for Alteration of the Radiation Issues Based on the Clipping Analyses of Radiation Articles Reported in Korea

  • Kim, Joo Yeon;Youn, Dol Mi;Yoo, Ji Yup;Park, Tai Jin
    • Journal of Radiation Protection and Research
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    • v.41 no.2
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    • pp.161-165
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    • 2016
  • Background: Radiation accidents having occurred in recent containing the accident in Fukushima nuclear power plants of Japan were resulted to the increase in some public concern, anxiety and confusion for radiation or nuclear safety. The public anxiety for radiation is not being decreased though the announcements done in radiation research institutes in Korea. Therefore, this study aims at providing an effective system for radiation publicity to the public members by the clipping analysis for the radiation articles reported in the media. And, the relation between those radiation issues and the radiation perception to the public members is analyzed. Materials and Methods: The radiation articles reported by them in 2013 and 2014 have been collected, and they are then classified with the article characteristic, field and tendency. Classified articles have been reviewed by dividing as two year. The 210 articles have been compared for their tendencies, characteristics and fields by year reported, and their characteristic comparison by reported year are then reviewed. Results and Discussion: Though the frequency that the radiological accidents have occurred in worldwide is far low compared to the accidental frequencies occurred in the general industrial fields, the radiation perception is being still deteriorated because of its special problem, which is defined as exposure, contamination or radioactivity, about radiation. The basic principles for radiation communication were suggested for preventing some unnecessary misunderstanding due to the variation of understanding for radiation issues. Conclusion: It is necessary to perform a variety of strategies for the publicity in improving the radiation perception, to build a relationship with the press or the media and then to consistently interact with them. Radiation communication must be performed by radiation experts or complete charge department, and must be consistently performed and be taken predictable patterns.