• Title/Summary/Keyword: low radiation

Search Result 2,615, Processing Time 0.032 seconds

Comparison of health outcomes according to intervention compliance in male Korean workers with metabolic syndrome (실천지침 이행률에 따른 대사증후군 중재 효과 비교: 직장인 남성 대사증후군을 대상으로)

  • Nam, Kyung-Hui;Kang, Ji-Yeon;Lee, Yeon-Ju;Sung, Sook-Hee;Chang, Youn-Koun;Lee, Ji-Young;Park, Ill-Keun;Choi, Tae-In
    • Journal of Nutrition and Health
    • /
    • v.46 no.2
    • /
    • pp.156-165
    • /
    • 2013
  • This study examined how achievement of session goals contributes to outcomes of subjects after participation in a 12-week lifestyle intervention program in men with metabolic syndrome (MetS). Thirty office workers with MetS, aged $47.2{\pm}6.6$ years, participated in this study, from March to July, 2011. The intervention program included face-to-face counseling five times during the 12-week period. Counselors and subjects designed session goals for each round. The average of the goal achievement rate was calculated based on compliance for each round. The subjects were divided into three groups according to their tertiles of achievement rate: Low-compliance group (LC, < 59%), medium-compliance group (MC, 59-70%), and high-compliance group (HC, > 70%). Anthropometry, biochemical index, and nutrient intake were examined at baseline and at the end of the 12-week intervention program. After the intervention, diastolic blood pressure (DBP) showed a significant decrease in the LC group, and waist circumference (WC) showed a significant decrease in the MC group. Systolic blood pressure (SBP), DBP, and low-density lipoprotein cholesterol (LDL) showed a significant decrease in the HI group. Changes in SBP and DBP were significantly lower in the HC group than in the MC group (p < 0.05, p < 0.01). Changes in LDL were significantly lower in the HC group than in the MC group (p < 0.05). Results for intake of total energy, protein, fat, and sodium, as well as rates of carbohydrate and fat intake, showed a significant decrease in all participants (p < 0.05). The change in fiber was significantly higher in the HC group than in the MC group (p < 0.05). The change of fruit serving size showed a significant increase in the HC group (p < 0.01). The number of risk factors for MetS showed a significant decrease in the LC and HC groups (p < 0.05), however, no significant mean differences were observed among the three groups. In conclusion, participation in this intervention program resulted in positive effects on risk factors for MetS, nutrient intake, and dietary habits, especially in the High-compliance group.

Evaluation of Fabricated Semiconductor Sensor for Verification of γ-ray Distribution in Brachytherapy (근접치료용 방사성 동위원소의 선량분포 확인을 위한 디지털 반도체 센서의 제작 및 평가)

  • Park, Jeong-Eun;Kim, Kyo-Tae;Choi, Won-Hoon;Lee, Ho;Cho, Sam-Joo;Ahn, So-Hyun;Kim, Jin-Young;Song, Yong-Keun;Kim, Keum-bae;Huh, Hyun-Do;Park, Sung-Kwang
    • Progress in Medical Physics
    • /
    • v.26 no.4
    • /
    • pp.280-285
    • /
    • 2015
  • In radiation therapy fields, a brachytherapy is a treatment that kills lesion of cells by inserting a radioisotope that keeps emitting radiation into the body. We currently verify the consistency of radiation treatment plan and dose distribution through film/screen system (F/S system), provide therapy after checking dose. When we check dose distribution, F/S systems have radiation signal distortion because there is low resolution by penumbra depending on the condition of film developed. In this study, We fabricated a $HgI_2$ Semiconductor radiation sensor for base study in order that we verify the real dose distribution weather it's same as plans or not in brachytherapy. Also, we attempt to evaluate the feasibility of QA system by utilizing and evaluating the sensor to brachytherapy source. As shown in the result of detected signal with various source-to-detector distance (SDD), we quantitatively verified the real range of treatment which is also equivalent to treatment plans because only the low signal estimated as scatters was measured beyond the range of treatment. And the result of experiment that we access reproducibility on the same condition of ${\gamma}$-ray, we have made sure that the CV (coefficient of variation) is within 1.5 percent so we consider that the $HgI_2$ sensor is available at QA of brachytherapy based on the result.

Calculation of Low-Energy Reactor Neutrino Spectra for Reactor Neutrino Experiments

  • Riyana, Eka Sapta;Suda, Shoya;Ishibashi, Kenji;Matsuura, Hideaki;Katakura, Jun-ichi
    • Journal of Radiation Protection and Research
    • /
    • v.41 no.2
    • /
    • pp.155-159
    • /
    • 2016
  • Background: Nuclear reactors produce a great number of antielectron neutrinos mainly from beta-decay chains of fission products. Such neutrinos have energies mostly in MeV range. We are interested in neutrinos in a region of keV, since they may take part in special weak interactions. We calculate reactor antineutrino spectra especially in the low energy region. In this work we present neutrino spectrum from a typical pressurized water reactor (PWR) reactor core. Materials and Methods: To calculate neutrino spectra, we need information about all generated nuclides that emit neutrinos. They are mainly fission fragments, reaction products and trans-uranium nuclides that undergo negative beta decay. Information in relation to trans-uranium nuclide compositions and its evolution in time (burn-up process) were provided by a reactor code MVP-BURN. We used typical PWR parameter input for MVP-BURN code and assumed the reactor to be operated continuously for 1 year (12 months) in a steady thermal power (3.4 GWth). The PWR has three fuel compositions of 2.0, 3.5 and 4.1 wt% $^{235}U$ contents. For preliminary calculation we adopted a standard burn-up chain model provided by MVP-BURN. The chain model treated 21 heavy nuclides and 50 fission products. The MVB-BURN code utilized JENDL 3.3 as nuclear data library. Results and Discussion: We confirm that the antielectron neutrino flux in the low energy region increases with burn-up of nuclear fuel. The antielectron-neutrino spectrum in low energy region is influenced by beta emitter nuclides with low Q value in beta decay (e.g. $^{241}Pu$) which is influenced by burp-up level: Low energy antielectron-neutrino spectra or emission rates increase when beta emitters with low Q value in beta decay accumulate Conclusion: Our result shows the flux of low energy reactor neutrinos increases with burn-up of nuclear fuel.

Accumulation of Chlorogenic Acid as a near UV-shielding Compound in Cauliflower Grown under Enhanced UV-B Radiation

  • Shibata, Hitoshi;Tanaka, Tomoyuki;Yonemura, Takeshi;Sawa, Yoshihiro;Ishikawa, Takahiro
    • Journal of Photoscience
    • /
    • v.9 no.2
    • /
    • pp.436-438
    • /
    • 2002
  • Since solar radiation contains wavelength essential for photosynthesis accompanying with near-UV light, UV-B effects on biological parameters and acclimation mechanisms are influenced by photosynthetically active radiation (PAR). Therefore, to elucidate near-UV shielding mechanism in higher plants, we cultivated cauliflower under usual solar radiation and increased UV-B from fluorescent lamps, two- or three-fold excess over continuously estimated UV-B dose in PAR during daytime, using computer regulated systems. Increased UV-B radiation had little effect on growth expressed as fresh weigh and leaf area. Water soluble low molecular weight compounds showing absorption in near UV region were enhanced according to the irradiated UV-B dose. One of compounds in cauliflower leaves was identified as chlorogenic acid. This was found to have no near-UV photosenSitizerable activity and is known to have an ability to scavenge a wide species of active oxygen. Another pro-oxidant compound that generates superoxide anion radical under near-UV irradiation was not induced by increased UV-B during cultivation, and identified as lumazine, a degradation product from folic acid.

  • PDF

Implementation of Electronic Personal Dosimeter Using Silicon PIN Photodiode (실리콘 핀 포토다이오드를 이용한 능동형 방사선 피폭 전자선량계의 구현)

  • 이운근;백광렬;권석근
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.9 no.4
    • /
    • pp.296-303
    • /
    • 2003
  • A personal portable type electronic dosimeter using silicon PIN photodiode and small GM tube is recently attracting much attention due to its advantages such as an immediate indication function of dose and dose rate, alerting function, and efficient management of radiation exposure history and dose data. We designed and manufactured a semiconductor radiation detector aimed to directly measure X-ray and v-ray irradiated in silicon PIN photodiode, without using high-priced scintillation materials. Using this semiconductor radiation detector, we developed an active electronic dosimeter, which measures the exposure dose using pulse counting method. In this case, it has a shortcoming of over-evaluating the dose that shows the difference between the dose measured with electronic dosimeter and the dose exposed to the human body in a low energy area. We proposed an energy compensation filter and developed a dose conversion algorithm to make both doses indicated on the detector and exposed to the human body proportional to each other, thus enabling a high-precision dose measurement. In order to prove its reliability in conducting personal dose measurement, crucial for protecting against radiation, the implemented electronic dosimeter was evaluated to successfully meet the IEC's criteria, as the KAERI (Korea Atomic Energy Research Institute) conducted test on dose indication accuracy, and linearity, energy and angular dependences.

A Study on Enforcement Effects of Radiation Safety Control Regulations for Diagnostic X-ray Equipments (진단용 방사선안전관리 현황에 관한 연구)

  • Sung, Mo-Il;Park, Myeong-Hwan;Kwon, Duk-Moon;Lee, Joon-Il
    • Journal of radiological science and technology
    • /
    • v.22 no.1
    • /
    • pp.73-78
    • /
    • 1999
  • The purposes of this study are to analyze the realities after enforcements of safety control regulations for diagnostic X-ray equipments and to suggest means for an improvement of low radiation safety control. A questionnaire survey for medical radiologic technologists was carried out to determine enforcement effects of the safety control regulations. The results of analysis from the survey are as follows. That is, most of the respondents realized the importance of the radiation safety control system, but about a half of them revealed that the regulations were not well observed in accordance with their purposes. Only 43.9% of the respondents took an active part in quality control and safety control of radiation. And respondents responsibility, sex, age, and knowledge for safety control were important indicators for observations of the regulations. Trainings for the safety control regulations are needed to ensure safety control and proper usage of diagnostic X-ray equipments. And management of organizations using diagnostic X-ray equipments have to understand and stress the importance of radiation safety control system.

  • PDF

Inspection of the spot welding using IR sensor (적외선 감지 센서를 이용한 점 용접부의 검사)

  • Lim, Dae-Cheol;Park, In-Tae;Kang, Hyoung-Shik;Gweon, Dae-Gab
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.16 no.1 s.94
    • /
    • pp.132-140
    • /
    • 1999
  • This paper suggests a monitoring method for the pulsed laser spot welding of the thin metal sheets using a point IR(InfraRed) sensor. A new criterion was introduced and the experimental results guaranteed the efficiency. The ideal radiation feature was derived from the mathematical model and was simulated. The radiation feature is robust to withstand the change of measuring condition and can be used to detect the absorbed laser energy. In an experiment, the radiation feature was examined for the differect laser energy. The pulse width and the laser power was variated and the radiation feature was examined. In the other experiment, the relationship between the weld strength and radiation feature was examined. Artificial Neural Network(ANN) was employed to find out the relationship. The correlation coefficient between the real strength and the estimated strength is high as 0.94 and the mean square error is low as 0.64 kgf learned parts. Another group of the welds was used to appraise the learning efficiency. The correlation coefficient between the measured and the estimated weld strength is high as 0.91.

  • PDF

Development of Radiation Heat Shield of Monopropellant Thruster for Spacecraft (우주비행체 단일추진제 추력기의 복사 열차폐막 개발)

  • 이균호;유명종;최준민;김수겸
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.34 no.10
    • /
    • pp.92-98
    • /
    • 2006
  • An 1 lbf of NASA standard monopropellant thruster, MRE-1, is used for KOMPSAT (Korea Multi-Purpose Satellite) which is launched in 2006 and provides reliable and cost-effective means for attitude and maneuvering control system. The monopropellant thruster obtains required thrust by thermal decomposition process of propellant through catalyst bed. During firing, the decomposition plays a role of a heat source that may occur an excessive radiation heat transfer to peripheral structures and electronics in relatively low temperature condition.Therefore, the radiation heat shield is needed to prevent the critical radiative heat exchange between thruster and satellite during firing. This paper summarizes an overall development process of radiation heat shield from the design engineering up to the manufacturing.

A Nuclear Event Detectors Fabrication and Verification for Detection of a Transient Radiation (과도방사선 검출을 위한 핵폭발 검출기 제작 및 검증)

  • Jeong, Sang-Hun;Lee, Seung-Min;Lee, Nam-Ho;Kim, Ha-Chul;Cho, Seong-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.62 no.5
    • /
    • pp.639-642
    • /
    • 2013
  • In this paper, proposed NED(nuclear event detectors) for detection of a transient radiation. Nuclear event detector was blocked of power temporary for defence of critical damage at a electric device when a induced transient radiation. Conventional NED consist of BJT, resistors and capacitors. The NED supply voltage of 5V and MCM(Multi Chip Module) structures. The proposed NED were designed for low supply voltage using 0.18um CMOS process. The response time of proposed NED was 34.8ns. In addition, pulse radiation experiments using a electron beam accelerator, the output signal has occurred.

Two Cystic Cavernous Angiomas after Radiotherapy for Atypical Meningioma in Adult Woman : Case Report and Literature Review

  • Ruggeri, Andrea Gennaro;Donnarumma, Pasquale;Pichierri, Angelo;Delfini, Roberto
    • Journal of Korean Neurosurgical Society
    • /
    • v.55 no.1
    • /
    • pp.40-42
    • /
    • 2014
  • A correlation between radiation therapy and cavernoma has been suspected since 1994. Since then, only a few cases of radio-induced cavernomas have been reported in the literature (85 patients). Most of them were children, and the most frequent original tumour had been medulloblastoma. The authors report a case of two cystic cavernous angiomas after radiation therapy for atypical meningioma in adult woman. This is the first case of cavernous angioma after radiotherapy for low grade meningioma. A 39-year-old, Latin american woman was operated on for a frontal atypical meningioma with intradiploic component and adjuvant radiotherapy was delivered (6000 cGy local brain irradiation, fractionated over 6 weeks). Follow-up MR imaging showed no recurrences of the tumour and no other lesions. Ten years later, at the age of 49, she consulted for progressive drug-resistant headache. MR imaging revealed two new well defined areas of different signal intensity at the surface of each frontal pole. Both lesions were surgically removed; the histopathological diagnosis was cavernous angioma. This is the first case of cavernous angioma after radiation therapy for atypical meningioma : it confirms the development of these lesions after standard radiation therapy also in patients previously affected by non-malignant tumours.