• Title/Summary/Keyword: Radiation level

Search Result 1,833, Processing Time 0.035 seconds

Protective Effect of Silkworm Hemolymph against Gamma Irradiation Induced Damage in the Liver of Mice (방사선 손상 Balb/C 마우스 모델에서 누에 체액(Silkworm Hemolymph)의 간조직 보호 효과)

  • Nam, You Ree;Kang, Jung Ae;Rho, Jong Kook;Choi, Mi Hee;Utami, Hayu Tyas;Jang, Beom Su;Park, Sang Hyun
    • Journal of Radiation Industry
    • /
    • v.8 no.1
    • /
    • pp.7-10
    • /
    • 2014
  • This study was designed to evaluate the protective effect of silkworm hemolymph against ${\gamma}-irradiation$ induced damage in the liver of mice. Female Balb/C mice (6 weeks old) were exposed to ${\gamma}-irradiation$ (6 Gy) and administered orally to silkworm hemolymph ($5ml\;kg^{-1}$ BW) for 7 days post-irradiation. The body weight, spleen index, plasma aspartate transaminase (AST), plasma alanine transaminase (ALT), and liver malondialdehyde (MDA) levels were determined. Compared with irradiated control mice, the activity of plasma AST and the level of MDA were significantly decreased in mice treated silkworm hemolymph. These results show that silkworm hemolymph is found to have a protective effect against ${\gamma}-irradiation$ induced damage in mice.

Review on Regulatory and Technical Standards of Radiation Protection for Lens of the Eye (수정체 방사선 방호에 관한 규제기준 및 기술기준 검토)

  • Si Young Kim;Seok-Ju Hwang;Jae Seong Kim;Jung-Kwon Son
    • Journal of Radiation Industry
    • /
    • v.18 no.1
    • /
    • pp.1-7
    • /
    • 2024
  • The International Commission on Radiological Protection (ICRP) lowered the annual equivalent dose limit of lens of the eye for radiation workers from 150 to 20 mSv in April 2011. This trend of lowering the equivalent dose limit for radiation workers has been observed worldwide, including international organizations such as the International Atomic Energy Agency (IAEA), International Organization for Standardization (ISO) and the European Commission (EC). In 2016, the Nuclear Safety and Security Commission of South Korea published research results that included a proposal for lowering the equivalent dose limit of lens of the eye for radiation workers in line with the ICRP recommendation. However, as of now, South Korea's Nuclear Safety Act and related regulations still specify an annual equivalent dose limit of lens of the eye as 150 mSv for radiation workers. The IAEA and ISO have issued guidelines regarding radiation protection for lens of the eye and recommended a dose level for the lens of the eye at 5 or 6 mSv per year for periodic monitoring of the equivalent dose for the lens of the eye.

A Survey on the Knowledge of Radiation Safety Management (RSM) in the Context of Industrial Use of Radiation (방사선의 산업적 이용에 따른 방사선 안전관리 지식 조사)

  • Ryu, Young-Hwan;Dong, Kyung-Rae;Chung, Woon-Kwan;Cho, Jae-Hwan;Park, Yong-Soon;Jung, Hong-Ryang
    • Journal of the Korean Society of Radiology
    • /
    • v.6 no.3
    • /
    • pp.159-166
    • /
    • 2012
  • The purpose of this study was examine via a survey the knowledge related to radiation safety management (RSM) among radiation workers who operated or used a radiation generator or radioactive isotopes (radioactive isotopes, etc. hereinafter) for industrial use and to systematically analyze the changes in the survey results in order to promote a radiation safety culture for facilities where radiation is used. We administered a questionnaire to 861 radiation workers in the period from August 1 to September 5, 2011. As for the analysis method, a frequency analysis was made for the general characteristics and organization information of survey respondents, while the average and standard deviation were calculated and compared for the knowledge level of the RSM. According to the analysis results, the knowledge level of the RSM was evaluated to be high in all of the radiation workers. In conclusion, it is required to conduct a study on various factors in regards to the RSM among radiation workers. This can contribute to establishing educational programs in a timely manner to increase the awareness of safe and efficient use of radioactive materials and equipments by radiation workers.

Differences between Each Requirement for Radiation Safety Regulation Levels (방사선안전규제 요건별 인식도 차이)

  • Han, Eun Ok;Cho, Dae Hyung
    • Journal of Radiation Protection and Research
    • /
    • v.37 no.4
    • /
    • pp.219-225
    • /
    • 2012
  • This study makes differentiated regulations which can maximize the efficiency and convenience of radiation safety regulations by deriving evidence required to establish reasonable safety regulatory structure based on the determination of the levels of actual radiation safety regulations for radiation safety managers to perform radiation safety. We surveyed approximately 10% of radiation safety managers from domestic radiation-using organizations which was based on the Nuclear Safety Act and NUREG Vol. 1~21 of RS-G-1.9 (2005), NRC of IAEA, etc. The radiation safety managers showed the highest level of awareness on the requirements for exposure management ($3.32{\pm}0.910$), and the lowest level on the requirements for record keeping and storage of documents ($2.84{\pm}0.826$). Industrial organizations showed higher levels of awareness than medical organizations whose regulations should be more stringent on requirements of the status and management of radioactive sources, facilities, measurements, pollution control, measuring equipment, monitoring, education and training, and exposure management. This suggests that the actual regulations need to be re-evaluated because it is attributed to the regulations which are statistically significant difference of the levels of radiation safety regulations between industrial organizations and medical organizations. The process of developing regulatory requirements for each characteristic of domestic organizations needs to be done in future studies, as well as safety regulations to maximize convenience should be achieved if radiation safety regulations are conducted in consideration with the characteristics of each organization.

Effects of $\gamma$-Irradiation on the Antiallergic Activity of Alginate

  • Song, Eu-Jin;Lee, So-Young;Kim, Koth-Bong-Woo-Ri;Park, Jin-Gyu;Kim, Jae-Hun;Lee, Ju-Woon;Byun, Myung-Woo;Ahn, Dong-Hyun
    • Food Science and Biotechnology
    • /
    • v.17 no.5
    • /
    • pp.1003-1009
    • /
    • 2008
  • This study was performed to determine the effects of $\gamma$-irradiation on the antiallergic activity of alginate. An alginate aqueous solution was $\gamma$-irradiated at 3, 5, 7, 10, 20, and 100 kGy. First, the molecular weight (Mw) of alginate rapidly decreased as the $\gamma$-irradiation dose increased up to 20 kGy. Then, the antiallergic activity of the $\gamma$-irradiated alginate was measured. Interlukin (IL)-4 cytokine and IgE level were significantly decreased in the $\gamma$-irradiated alginate groups as compared to the control group in vitro. The mice intraperitoneally administered with the $\gamma$-irradiated alginate exhibited lower ovalbumin-specific IgE and IgG1 level in serum than the control mice. Furthermore, the $\gamma$-irradiated alginate suppressed total and ovalbumin-specific IgE secretions in the splenocytes. Increased IL-2 level was observed in the culture supernatants of the splenocytes that were obtained from the mice administerd with the $\gamma$-irradiated alginate, while IL-4 level decreased. The present study indicates that $\gamma$-irradiated alginate can suppress allergy in a mouse allergy model.

Evaluation of Diagnostic Reference Level in Interventional Procedures (인터벤션시술 진단참고수준 평가)

  • Kang, Byung-Sam;Park, Hyung-Shin
    • Journal of radiological science and technology
    • /
    • v.44 no.5
    • /
    • pp.451-457
    • /
    • 2021
  • Recently, the number of interventional procedures has increased dramatically as an alternative of invasive surgical procedure and patient radiation exposure is also increasing accordingly. In this study, we evaluated the patient dose of major interventional procedures nationwide and we established our Korean database. With these results, we tried to suggest the reference dose level for major interventional procedures. We evaluated patent dose data in the field of interventional radiology from foreign countries. Measurement of radiation dose exposure for 11 major interventional procedures was conducted using embedded DAP meters in 10,006 patients from 47 hospitals, and reference level of each interventional procedure was suggested. The DRLs of each intervenional procedure are as follows: TACE 206(Gy·cm2), AVF 12(Gy·cm2), LE intervention 43(Gy·cm2), TFCA 122(Gy·cm2), Cerebral aneurysm coil embolization 214(Gy·cm2), PTBD 22(Gy·cm2), Biliary stent 60(Gy·cm2), PCN 7(Gy·cm2), Hickman catheter 2.1(Gy·cm2), Chemoport 1.4(Gy·cm2), BAE 104(Gy·cm2). Compared with the previously established DRL in 2012, the radiation dose decreased in all 10 interventional procedures. In the future, continuous publicity and education on the radiation dose reduction will be needed.

Analysis of Importance, Understanding Level and Needs by Subject of College Students Preparing for Radiological Technologists National Examination (방사선사 국가시험 준비를 위한 대학생들의 과목별 중요도와 이해도 수준 및 요구도 분석)

  • Young-Lock, Kim;Jae-Hong, Jung;Dae-Gun, Kim
    • Journal of radiological science and technology
    • /
    • v.46 no.1
    • /
    • pp.53-61
    • /
    • 2023
  • The aim of this study analyzed the important level (IL) and understanding level (UL) including the Borich's need for students preparing of the national examination for radiological technologists at online open chatting room. A total of 254 survey were collected from a total of 1,016 students who used open chatting room from December 13 to December 16, 2022. A general characteristics were the age, gender, curriculum (3 or 4 years), grade and area. The IL, UL, learning satisfaction (LS), learning achievement (LA) and intention to continue using (ICU) were analyzed by using the 5 point Likert scale. There was no significant difference the LS, LA, and ICU according to general characteristics (p>0.05). There was a statistically significant difference a total of sixteen subjects based on the t-test results of the response values from the IL and UL (p<0.05). The total of ten subjects with the highest priority in the Locus for Focus models were the Ultrasonography, Human anatomy, Magnetic resonance imaging, Radiation therapy, Cardiovascular and intervention, Computed tomography, Human physiology, Radiographic imaging, Fluroscopic radiography, and Nuclear medicine) that the Borich's need was also the same as the top 10 ranked subjects. The LS (4.23±0.72), LA (4.18±0.73), and ICU (4.15±0.78) for open chatting room were high. This study identified the subjects most needed by college students by the Borich's need analysis. First, it is necessary to provide intensive education on subjects with high scores that are most needed by college students. Second, it is necessary to improve the teaching method for subjects with low need and low level of understanding.

Jet-Edge Interaction and Sound Radiation in Edgetones (쐐기소리에서 분류-쐐기의 상호작용과 소리의 방사)

  • ;Powell A.
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.18 no.3
    • /
    • pp.584-590
    • /
    • 1994
  • A theoretical model has been developed to analyze the jet-edge interaction and the sound radiation. The edge responding to the sinuous impinging jet is regarded as an array of dipoles and their strength is determined by the boundary condition on the edge surface. The surface pressure distribution and the edgeforce are estimated using these dipoles. Then the pressure amplitude and directivity of the sound field is obtained by summing the radiating sounds from the dipole sources. It is found that the effective source is located a little distance downstream from the edge tip. And the directivity of the sound radiation is cardioid pattern near the edge but dipole pattern far from the edge. The theoretical model is confirmed by comparing the theoretical prediction of the edgeforce and sound pressure level with available experimental data.

A Study of Electromagnetic Interference in Power Line Communication (전력선 통신에서의 전자파 장해에 관한 연구)

  • Lee Jin-Taek;Chun Dong-Wan;Park Young-Jin;Lee Won-Tae;Shin Chul-Chai
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.53 no.12
    • /
    • pp.620-625
    • /
    • 2004
  • In this paper, we studied the emissive electric field due to the communication signal and the noise in medium voltage power-line. There are many types of conductive noise in power-line channel, which gives rise to radiation. And if the DMT carrier signal was excited, the current by this term was added to the current by noise and, generate radiation. We calculated input impedance by means of signal input network model of medium voltage power-line channel for calculating these currents. We calculated currents by input impedance and, calculated the emissive electric field by this calculated currents. From the measurement results, we knew that the measured results are very similar to the calculated results and if the input signal power level was higher than -40 dBm, the emissive electric field exceeds FCC radiation limit level 69.5 dB$\mu$V/m.

The Influence of Radiation Trapping on the Metastable Population Density and Applications to Low-pressure Plasma

  • Lee, Yeong-Gwang;O, Se-Jin;Jeong, Jin-Uk
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2011.02a
    • /
    • pp.245-246
    • /
    • 2011
  • Emission lines ratios were used for diagnostics of and excited level densities in low-temperature plasmas. In this work, an optical emission spectroscopy (OES) was used to determine the electron temperature and metastable level densities in low-pressure inductively coupled plasma. The emission spectroscopy method was based on a simple collisional-radiative model. The selected lines of the Ar(4p to 4s) were influenced by the radiation trapping at relatively high pressures where the plasma become optically thick. To quantify this effect, a pressure dependence factor ${\alpha}$(P) was derived by using corrections for the measured intensities. It was found that the lower metastable level densities were obtained when ${\alpha}$(P) increased with the increasing discharge pressure. The effect of non-Maxwellian electron energy distribution functions (EEDFs) on the metastables was also presented and discussed.

  • PDF