• Title/Summary/Keyword: Radiations

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A STUDY ON THE SIMULTANEOUS MEASUREMENTS OF BETA EMITTING ISOTOPES

  • Lee, Goung-Jin;Kim, Seoung-Pyung
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.155-159
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    • 2001
  • Beta radiation is measured for an environmental monitoring purpose or for an internal radiation exposure monitoring of nuclear power plant's worker. In korea, strontium 89 and strontium 90 is measured for an environmental monitoring purpose. Also tritium and carbon 14 contained in urine is measured for an internal radiation exposure monitoring of nuclear power plant's worker. Because above isotopes emits low energy beta radiations having a wide range of energy, very complicated isotope separation preprocess is needed. In this study, two mixed beta emitting isotopes are measured simultaneously using a liquid scintillation counter(LSC) and analyzed by using a developed statistical method. Banded least square method is used to analyze the mixed spectrum, and the goodness-of-fitness test is proposed. Test results show that the developed procedure can be very useful for analyzing a mixed beta emitting isotopes.

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Relationships between LET and RBE of lonizing Radiation in the induction of Somatic Mutations of Drosophila melanogaster

  • 유미애;정운혁;이원호
    • Environmental Mutagens and Carcinogens
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    • v.7 no.2
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    • pp.103-111
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    • 1987
  • The effects of LET (linear energy transfer) of radiation on the induction of somatic chromosome mutations or gene mutations of Drosophila melanogaster were studied. For detecting somatic chromosome mutations and gene mutations, Drosophila wing spot system and eye-color spot system were used, respectively. The frequencies of somatic chromosome mutations or gene mutations induced after third instar larval treatment with 23 MeV neutrons, thermal neutrons, X-rays were examined. From these data, the RBE(relative biological effectiveness) values of 23 MeV neutrons relative to X-rays for induction of somatic chromosome mutations or gene mutations were calculated. The present results suggest that high LET radiations are efficient than X-ray in producing not only somatic chromosome mutations but also gene mutations.

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Pediatric Magnetic Resonance Enterography: Focused on Crohn's Disease

  • Lee, So Mi;Kim, Woo Sun;Choi, Young Hun
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.18 no.3
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    • pp.149-159
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    • 2015
  • Crohn's disease is a chronic idiopathic inflammatory disease of the intestines characterized by frequent relapse and remission. It often develops in children and adolescents, who are vulnerable to repeated exposure to ionizing radiations. Magnetic resonance enterography (MRE) is an increasingly important radiation-free imaging modality that is used to evaluate pediatric patients with Crohn's disease. MRE can evaluate extraluminal and extraintestinal abnormalities as well as the status of the bowel wall. In addition, MRE has an advantage in the evaluation of the small bowel involvement. MRE can be used for the initial diagnosis of Crohn's disease, and can aid in the assessment of disease activity and complications such as penetrating and fibrostenotic diseases. The aims of this article are to review the MRE technique for obtaining diagnostic and high-quality images and to discuss interpretations of imaging findings in patients with Crohn's disease.

Characteristics of Meteorological Elements and Long-wave Radiation in the Greater Daegu Area During Winter (동절기 대구지역의 기상요소와 장파복사 특성 분석)

  • Baek, Chang-Hyeon;Choi, Dong-Ho;Lee, Bu-Yong;Lee, In-Gyu
    • Journal of the Korean Solar Energy Society
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    • v.37 no.6
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    • pp.93-102
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    • 2017
  • Interpretation of relevance between long-wave radiation and meteorological elements is recognized as an essential element for understanding the underlying mechanism of urban thermal environment formation. In this study, we analyzed relation between three elements : long-wave radiation, temperature, and lower-middle class cloudiness. The correlation was analyzed through field observations. The results are as follows. (1) Temperatures and long-wave radiation increased from January to March. This phenomenon has been confirmed in urban and suburban areas. (2) Long-wave radiations showed a tendency to increase clearly with increasing cloudiness.

Temporal and Spatial Distributions of the Surface Solar Radiation by Spatial Resolutions on Korea Peninsula (한반도에서 해상도 변화에 따른 지표면 일사량의 시공간 분포)

  • Lee, Kyu-Tae;Zo, Il-Sung;Jee, Joon-Bum;Choi, Young-Jean
    • New & Renewable Energy
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    • v.7 no.1
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    • pp.22-28
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    • 2011
  • The surface solar radiations were calculated and analyzed with spatial resolutions (4 km and 1 km) using by GWNU (Gangneung-Wonju National University) solar radiation model. The GWNU solar radiation model is used various data such as aerosol optical thickness, ozone amount, total precipitable water and cloud factor are retrieved from Moderate Resolution Imaging Spectrometer (MODIS), Ozone Monitoring Instrument (OMI), MTSAT-1R satellite data and output of the Regional Data Assimilation Prediction System(RDAPS) model by Korea Meteorological Administration (KMA), respectively. The differences of spatial resolutions were analyzed with input data (especially, cloud factor from MTSAT-1R satellite). And the Maximum solar radiation by GWNU model were found in Andong, Daegu and Jinju regions and these results were corresponded with the MTSAT-1R cloud factor.

Experimental and Theoretical Study on Main Noise Sources and Its Radiations of Upwind Wind Turbines (상류형 풍력 터빈의 주요 소음원과 방사소음에 대한 실험적/이론적 고찰)

  • Lee, Gwang-Se;Cheong, Cheol-Ung;Shin, Su-Hyun;Jung, Sung-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2010.05a
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    • pp.72-73
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    • 2010
  • In this paper, the main noise sources and its radiated noise levels of upwind horizontal-axis wind turbines are experimentally and theoretically investigated. Theoretical predictions for indentifying the dominant source locations are made by using the empirical noise prediction model of Brooks et al. (1989) for the airfoil self noise. Through the comparison of theoretical results with the experimental results, turbulence-boundary-layer-trailing-edge (TBL-TE) noise is revealed to be the dominant source over all frequency range and separation and stall (S-S) noise is possibly important in the relative lower frequency range compared with TBL-TE noise.

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The Physical Methods for Induction of Anti-Bacterial Substances in the Silkworm Larva, Bombyx mori

  • Gui, Zhongzheng;Dai, Jianyi;Zhuang, Dahuan
    • International Journal of Industrial Entomology and Biomaterials
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    • v.7 no.2
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    • pp.231-233
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    • 2003
  • To understand the physical method for induction of anti-bacterial substances from the silkworm larvae, Bombyx mori, three physical methods, i.e., infrared radiation, ultraviolet radiation and ultrasonic wave, have been used in this study. The results have shown that ultrasonic wave can induce anti-bacterial sub-stances effectively than radiations in the B. mori larva. The induction of anti-bacterial substances was different from silkworm race to race. Summer-autumn silkworm race (Qiufeng${\times}$Baiyu) was easy to induce antibacterial substances. It is suggested that the ultrasonic wave is a simple and easy method for induction.

A CASE REPORT OF RADIATION THERAPY FOR ORAL SQUAMOUS CELL CARCINOMA (구강편평상피세포암에 대한 방사선 치험예)

  • Suh, Jene-Kwan;Kwon, Hak-Joo;Ahn, Choon-Kil;Lee, Yong-Oh;Shin, Moon-Hyok;Oh, Chang-Min;Lee, Jong-Kil
    • The Journal of the Korean dental association
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    • v.10 no.2
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    • pp.87-90
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    • 1972
  • The carcinoma of the maxillary sinus occupies about 0.25% of all human cancers. The radiations therapy for maxillary sinus hs not been practiced widely in this country. The authors treated a case of relatively advanced maxillary sinus cancer with combined radium and external irradiation with a succesful result. The clinical course and treatment are introduced and evaluated in detail. The authors believe that the carcinoma of the maxillary sinus is a curable disease even though it is relatively advanced one.

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Ionizing Radiations Induce Apoptosis in TRAIL Resistant Cancer Cells: in vivo and in vitro Analysis

  • Silva, Marcela Fernandes;Khokhar, Abdur Rehman;Qureshi, Muhammad Zahid;Farooqi, Ammad Ahmad
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.1905-1907
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    • 2014
  • Increasingly it is being realized that despite considerable advancements in therapeutic interventions related to treatment of cancer, satisfactory results are still difficult to achieve. Rapidly accumulating evidence has started to shed light on the fact that cancer cells escape from death via constitutive activation of pro-survival signaling cascades. Cell biology and genetics have extensively enhanced our current understanding of the molecular mechanisms that underlie loss of apoptosis in cancer cells. This review is focused on ionizing radiation mediated restoration of TRAIL mediated apoptosis as evidenced by cell culture and animal model studies. Moreover, we also bring to the limelight radiation induced expression of miRNAs and how miRNAs further control response of cancer cells to radiation.

Reconsideration of CN Radiation an d $C_2$ Dissociation Rate Coefficient ($C_2$의 해리 반응 계수와 CN 복사에 대한 재고찰)

  • Hyun, Seong-Yoon;Park, Chul;Chang, Keun-Shik
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.92-95
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    • 2008
  • We performed the theoretical calculation of CN Violet radiation using the code SPRADIAN07 to predict the Lee et al.'s experimental measurements and to reinvestigate $C_2$ dissociation rate. CN Violet radiations are calculated under the Boltzmann and non-Boltzmann distribution using two chemical reaction sets: Park-Losev-G\"{o}kcen-Tsang and Park-Losev-G\"{o}kcen-Tsang-Lee models. Our SPRADIAN07 calculations show improvement in prediction of absolute radiation intensity of CN Violet and its decay rate by Park-Losev-G\"{o}kcen-Tsang reaction set with $C_2$ dissociation rate coefficient of $k_f$ = 1.5${\times}$10$^{16}$ exp(-71,600/$T_x$) cm$^3$ mole$^{-1}$ s$^{-1}$.

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