Оптические характеристики облученных гамма-лучами полимерных сцинтилляторов

The effects of dose rate and dose of 60Co gamma-irradiation and oxidation on optical transmission and absorption spectra of plastic scintillators of BC-408 (USA), UPS-923A (Ukraine) and LHE (JINR) were studied at 300 K in air and hermetic pack at dose rates within 0.00022 до 0.0032 МGy/h and to doses 0.043 и 0.2 МGy. The irradiation increases the transmission losses in the range of 400-850 nm as the dose grows. It was not found a noticeable influence of adsorbed oxygen on the induced optical losses at the mentioned conditions.

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Sintering of Textured YBa2Cu307-x Under Intensive 60Co Gamma Irradiation

MRS Proceedings ◽

10.1557/proc-354-723 ◽

1994 ◽

Vol 354 ◽

Cited By ~ 1

Author(s):

Elvira M. Ibragimova ◽

Eldar M. Gasanov ◽

Makhmud Kalanov ◽

Marquis A. Kirk ◽

Ken C. Goretta

Keyword(s):

Gamma Irradiation ◽

Dose Rate ◽

Subsurface Layer ◽

Gamma Dose ◽

Ordered Structure ◽

Sintering Process ◽

Superconducting Properties ◽

Oxygen Sublattice ◽

60Co Gamma ◽

Sem Analyses

AbstractA study of structural and superconducting characteristics of YBa2Cu307-x ceramics sintered after and in the course of gamma-irradiation is reported. Using X-difraction and SEM analyses and transport measurements, it has been shown that mainly the subsurface layer of crystallites and intergrain contacts are affected by the irradiation by means of sorption/desorption of oxygen and ordering/disordering in oxygen sublattice, which depends on gamma dose rate and dose. The irradiation provides the sintering process with an additional superthermal energy to form the orthorhombic well-ordered structure and to obtain dense ceramics possessing strong intergrain contacts and improved and stable superconducting properties

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Comparisons of Cobalt-60 Gamma Irradiation Dose Rates on Grapefruit Flavedo Tissue and on Mexican Fruit Fly Mortality

Journal of Food Protection ◽

10.4315/0362-028x-53.4.329 ◽

1990 ◽

Vol 53 (4) ◽

pp. 329-331 ◽

Cited By ~ 7

Author(s):

GENE E. LESTER ◽

DAN A. WOLFENBARGER

Keyword(s):

Gamma Irradiation ◽

Dose Rate ◽

Electrolyte Leakage ◽

Irradiation Dose ◽

Adult Emergence ◽

Fruit Fly ◽

Anastrepha Ludens ◽

Mexican Fruit Fly ◽

Dose Rates ◽

Grapefruit Peel

Percent electrolyte leakage, a measure of membrane integrity, proved to be a good predictor (R2 = 0.99) of cobalt-60 gamma irradiation dose injury on mid-season ‘Ruby Red’ grapefruit Citrus paradisi (Macf.) flavedo tissue (peel). Percent electrolyte leakage on grapefruit peel following a dose-rate of 250 grays/1.0, 2.5, 5.0, and 25.0 min decreased as grays/min (dose-rate) decreased. Total phenols, a biochemical response to irradiation following 250 grays/1.0, 2.5, 5.0, and 25.0 min also decreased as dose-rate decreased, demonstrating that injury to grapefruit peel diminished as 250 grays of gamma irradiation/rate declined. Comparisons of 10 and 20 grays of cobalt-60 gamma irradiation showed that a dose-rate of 10 grays/0.25 min to naked 8-d old Mexican fruit fly Anastrepha ludens (Loew) larvae caused a 90% reduction of adult emergence. Whereas, at 20 grays the reduction was greater than 99% with dose-rates of 20 grays/0.25, 0.5, 1.0, or 100 min. These data show that a gamma irradiation dose capable of reducing fly emergence by >99% will maintain an inhibitory effect even at relatively lower dose-rates. Therefore, once a quarantine security treatment for Mexican fruit fly is established, a lower dose-rate will reduce adult emergence and should impart little damage to grapefruit peel tissue.

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Gamma irradiation used on adult Tetranychus urticae Koch as a quarantine treatment

Journal of Plant Protection Research ◽

10.2478/jppr-2014-0024 ◽

2014 ◽

Vol 54 (2) ◽

pp. 150-155 ◽

Cited By ~ 3

Author(s):

Shiva Osouli ◽

Karim Haddad Irani Nejad ◽

Farhoud Ziaie ◽

Mohammad Moghaddam

Keyword(s):

Gamma Radiation ◽

Gamma Irradiation ◽

Dose Rate ◽

Tetranychus Urticae ◽

Linear Trend ◽

Young Females ◽

Dose Rates ◽

Adult Females ◽

Tetranychus Urticae Koch ◽

Old Females

Abstract The effect of gamma radiation with 0, 200, 250, 300, 350, 400, and 450 Gy intensities on the longevity, total number of eggs, and the percent of hatched eggs laid by irradiated females of Tetranychus urticae Koch (Tetranychidae) was evaluated. Two different groups (0–24 h old and 48–72 h old) of adult females were irradiated. The results showed that 350 and 300 Gy doses significantly reduced the longevity of the 0–24 h old females and the 48–72 h old females. The younger females were more tolerant at lower dose rates than the older females. There was a quadratic relationship between dose rates and young females, while it was linear in older females. The total number of eggs laid by females of both ages was significantly reduced with a linear trend by 250 Gy irradiation. The eggs laid by females of both the 0–24 h olds and the 48–72 h olds lost their hatchability when the dose rate was 350 Gy. It was concluded, that applying a dose rate of 320 Gy on one of the mates (male or female) before mating, or a 300 Gy on both of them, would be sufficient to cause sterility in adult mites.

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Radiation Awareness for Endovascular Abdominal Aortic Aneurysm Repair in the Hybrid Operating Room: An Instant Operator Risk Chart for Daily Practice

Journal of Endovascular Therapy ◽

10.1177/15266028211007458 ◽

2021 ◽

pp. 152660282110074

Author(s):

Quirina M. B. de Ruiter ◽

Frans L. Moll ◽

Constantijn E. V. B. Hazenberg ◽

Joost A. van Herwaarden

Keyword(s):

Radiation Dose ◽

Dose Rate ◽

Effect Size ◽

Radiation Risk ◽

Dose Limit ◽

Access Site ◽

Femoral Access ◽

Dose Rates ◽

Rate Prediction ◽

Operator Dose

Introduction: While the operator radiation dose rates are correlated to patient radiation dose rates, discrepancies may exist in the effect size of each individual radiation dose predictors. An operator dose rate prediction model was developed, compared with the patient dose rate prediction model, and converted to an instant operator risk chart. Materials and Methods: The radiation dose rates (DRoperator for the operator and DRpatient for the patient) from 12,865 abdomen X-ray acquisitions were selected from 50 unique patients undergoing standard or complex endovascular aortic repair (EVAR) in the hybrid operating room with a fixed C-arm. The radiation dose rates were analyzed using a log-linear multivariable mixed model (with the patient as the random effect) and incorporated varying (patient and C-arm) radiation dose predictors combined with the vascular access site. The operator dose rate models were used to predict the expected radiation exposure duration until an operator may be at risk to reach the 20 mSv year dose limit. The dose rate prediction models were translated into an instant operator radiation risk chart. Results: In the multivariate patient and operator fluoroscopy dose rate models, lower DRoperator than DRpatient effect size was found for radiation protocol (2.06 for patient vs 1.4 for operator changing from low to medium protocol) and C-arm angulation. Comparable effect sizes for both DRoperator and DRpatient were found for body mass index (1.25 for patient and 1.27 for the operator) and irradiated field. A higher effect size for the DRoperator than DRpatient was found for C-arm rotation (1.24 for the patient vs 1.69 for the operator) and exchanging from femoral access site to brachial access (1.05 for patient vs 2.5 for the operator). Operators may reach their yearly 20 mSv year dose limit after 941 minutes from the femoral access vs 358 minutes of digital subtraction angiography radiation from the brachial access. Conclusion: The operator dose rates were correlated to patient dose rate; however, C-arm angulation and changing from femoral to brachial vascular access site may disproportionally increase the operator radiation risk compared with the patient radiation risk. An instant risk chart may improve operator dose awareness during EVAR.

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Enhanced Low Dose Rate Sensitivity of PNP Transistor at Extreme-Low Dose Rates

2018 18th European Conference on Radiation and Its Effects on Components and Systems (RADECS) ◽

10.1109/radecs45761.2018.9328712 ◽

2018 ◽

Author(s):

Mohan Liu ◽

Wu Lu ◽

Xin Wang ◽

Xing Yu ◽

Jing Sun ◽

...

Keyword(s):

Dose Rate ◽

Low Dose ◽

Rate Sensitivity ◽

Dose Rates ◽

Low Dose Rate

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60Co Gamma Irradiation and Annealing Effects on Transport Properties of Antimony Telluride Platelets Grown by Physical Vapor Deposition

Acta Metallurgica Sinica (English Letters) ◽

10.1007/s40195-015-0232-x ◽

2015 ◽

Vol 28 (5) ◽

pp. 559-566

Author(s):

Thankamma George ◽

A. G. Kunjomana

Keyword(s):

Gamma Irradiation ◽

Transport Properties ◽

Vapor Deposition ◽

Physical Vapor Deposition ◽

Antimony Telluride ◽

60Co Gamma ◽

Annealing Effects

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Kinetics of DNA Repair Under Chronic Irradiation at Low and Medium Dose Rates in Repair Proficient and Repair Compromised Normal Fibroblasts

Radiation Research ◽

10.1667/rade-21-00158.1 ◽

2021 ◽

Author(s):

Elena K. Zaharieva ◽

Megumi Sasatani ◽

Kenji Kamiya

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Dose Rate ◽

Dose Response ◽

Chronic Irradiation ◽

Dose Rates ◽

Chronic Radiation ◽

Damage Repair ◽

Kinetics Of ◽

Medium Dose

We present time and dose dependencies for the formation of 53BP1 and γH2AX DNA damage repair foci after chronic radiation exposure at dose rates of 140, 250 and 450 mGy/day from 3 to 96 h, in human and mouse repair proficient and ATM or DNA-PK deficient repair compromised cell models. We describe the time/dose-response curves using a mathematical equation which contains a linear component for the induction of DNA damage repair foci after irradiation, and an exponential component for their resolution. We show that under conditions of chronic irradiation at low and medium dose rates, the processes of DNA double-strand breaks (DSBs) induction and repair establish an equilibrium, which in repair proficient cells manifests as a plateau-shaped dose-response where the plateau is reached within the first 24 h postirradiation, and its height is proportionate to the radiation dose rate. In contrast, in repair compromised cells, where the rate of repair may be exceeded by the DSB induction rate, DNA damage accumulates with time of exposure and total absorbed dose. In addition, we discuss the biological meaning of the observed dependencies by presenting the frequency of micronuclei formation under the same irradiation conditions as a marker of radiation-induced genomic instability. We believe that the data and analysis presented here shed light on the kinetics of DNA repair under chronic radiation and are useful for future studies in the low-to-medium dose rate range.

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Chronic exposure to gamma irradiation at low-dose rates accelerates blood pressure decline associated with aging in female B6C3F1 mice

International Journal of Radiation Biology ◽

10.1080/09553002.2019.1552808 ◽

2019 ◽

Vol 95 (3) ◽

pp. 347-353 ◽

Cited By ~ 1

Author(s):

Daisaku Takai ◽

Akiko Abe ◽

Jun-ichiro Komura

Keyword(s):

Blood Pressure ◽

Gamma Irradiation ◽

Chronic Exposure ◽

Low Dose ◽

Dose Rates ◽

B6c3f1 Mice

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Serum Metabolomic Alterations Associated with Cesium-137 Internal Emitter Delivered in Various Dose Rates

Metabolites ◽

10.3390/metabo10070270 ◽

2020 ◽

Vol 10 (7) ◽

pp. 270

Author(s):

Heng-Hong Li ◽

Yun-Tien Lin ◽

Evagelia C. Laiakis ◽

Maryam Goudarzi ◽

Waylon Weber ◽

...

Keyword(s):

Dose Rate ◽

Cumulative Dose ◽

Low Dose ◽

Biological Effects ◽

Serum Samples ◽

Dose Rates ◽

Sphingosine 1 Phosphate ◽

Cesium 137 ◽

Dose Rate Effect ◽

Medium Dose

Our laboratory and others have use radiation metabolomics to assess responses in order to develop biomarkers reflecting exposure and level of injury. To expand the types of exposure and compare to previously published results, metabolomic analysis has been carried out using serum samples from mice exposed to 137Cs internal emitters. Animals were injected intraperitoneally with 137CsCl solutions of varying radioactivity, and the absorbed doses were calculated. To determine the dose rate effect, serum samples were collected at 2, 3, 5, 7, and 14 days after injection. Based on the time for each group receiving the cumulative dose of 4 Gy, the dose rate for each group was determined. The dose rates analyzed were 0.16 Gy/day (low), 0.69 Gy/day (medium), and 1.25 Gy/day (high). The results indicated that at a cumulative dose of 4 Gy, the low dose rate group had the least number of statistically significantly differential spectral features. Some identified metabolites showed common changes for different dose rates. For example, significantly altered levels of oleamide and sphingosine 1-phosphate were seen in all three groups. On the other hand, the intensity of three amino acids, Isoleucine, Phenylalanine and Arginine, significantly decreased only in the medium dose rate group. These findings have the potential to be used in assessing the exposure and the biological effects of internal emitters.

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