Showing results for: gamma ray dose Articles
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Natural radiation level in the environment of Tehri Garhwal, Uttaranchal
The natural radiation levels were measured in about 50 residential houses of Tehri Garhwal, Uttaranchal, using an environmental radiation dosimeter in both the indoor and the outdoor atmosphere. The total gamma ray activity was found to vary from 29.74 µR/h to 41.19 µR/h with a mean of 36.5 µR/h for the indoor environment, whereas for outdoors it varied from 28.76 µR/h to 43.46 µR/h with a mean ...
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Performance of some handheld dosimeters used for gamma–ray ambient dose rate measurements
A study was carried out on the performance of some handheld dosimeters that are used for measuring ambient gamma dose rates. A CsI scintillation–based and two GM–based dosimeters were used to measure the absorbed dose rates in an indoor environment, inside a lead shield, on different floors of a building, in a desert environment and in a boat on the Arabian Gulf. The study showed that while some ...
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Dose response of polyvinyl alcohol films dyed by methyl red under gamma irradiation
Polyvinyl Alcohol (PVA) films containing Methyl Red (MR) were prepared by the cast drying of an aqueous solution of the constituents. Irradiation was performed in air at room temperature with 60Co gamma rays at a dose rate of 0.9 kGy/h. The characteristics of the films were analysed by a spectrophotometer and densitometer. The dose response of the films was described by the energy transfer model. ...
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Unusual cellular effects of small doses of radiation: a massive, persisting, dose-independent increase in yield of ultrastructural pathology in the rat nephrocyte population
Electron microscopy and optical tests were used to observe the occurrence of damaged cells in the epithelium of renal tubules in white non-breed male rats after being irradiated with gamma rays in doses of 0.25 and 1.5 Gy. The duration of the study was 6 months. The data obtained were analysed from the viewpoint of the phenomenon of 'nonstochastic effects of low doses', which had been discovered ...
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Survey of natural and artificial radioactivity in Tunisian soils
A study of the natural radioactivity and artificial radioactivity of soils due to gamma ray emitters was performed in Tunisia, as part of the national programme for environment surveillance. Seventeen sites were studied. The determination of radionuclide specific concentrations in the soil samples (0–5 cm) by gamma ray spectrometry showed the following ranges: 40K (93–319 Bq/kg), 226Ra (5–50 ...
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Effect of low doses and low dose-rates of gamma radiation on DNA damage in human peripheral blood leukocytes using comet assay
Comet assay is a sensitive technique and it provides a unique opportunity to investigate intercellular differences in DNA damage and repair in any eukaryotic cell population. This assay can be used to detect DNA single strand breaks, alkali-labile sites and incomplete DNA repair sites, under alkaline conditions and DNA double strand breaks under neutral condition. We report here our observations ...
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Study of the effect of post-irradiation with low linear energy transfer on optical and spectral response of CR-39 polymeric material
The optical properties of CR-39 polymer track detectors irradiated with high Linear Energy Transfer (LET) (alpha particles at energies 3.05 MeV and 4.86 MeV) and followed by low LET (gamma ray irradiation at different doses ranging from 0 to 200 kGy) were investigated. The chemical etching was verified for all samples. Also, the optical properties were studied with an Ultraviolet-Visible (UV-VIS) ...
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Measurements of 226Ra, 232Th and 40K using gamma spectrometry to assess a first-order exposure risk for residents of Western Haryana, India
The measurements of 226Ra, 232Th and 40K using gamma spectrometry and measurements of radon concentration and exhalation rates using solid-state nuclear track (LR-115, Type-II plastic) detectors were used to assess a first-order exposure risk for people residing in the Fatehbad and Hissar districts in Western Haryana, India. The concentrations of radium, thorium and potassium in the soil samples ...
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Study of the effect of post-irradiation with low linear energy transfer on optical and spectral response of CR-39 polymeric material
The optical properties of CR-39 polymer track detectors irradiated with high Linear Energy Transfer (LET) (alpha particles at energies 3.05 MeV and 4.86 MeV) and followed by low LET (gamma ray irradiation at different doses ranging from 0 to 200 kGy) were investigated. The chemical etching was verified for all samples. Also, the optical properties were studied with an Ultraviolet-Visible (UV-VIS) ...
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Suppression of carcinogenic processes in mice by chronic low dose rate gamma-irradiation
Effects of low dose rate radiation on the process of carcinogenesis induced by a chemical carcinogen were examined. ICR female mice, 35 or 36 mice for each group, were kept and exposed to 137Cs gamma-rays in the long-term low dose rate irradiation facility at the Central Research Institute of Electric Power Industry at a dose rate of 0.3, 0.96, or 2.5 mGy/h. Thirty-five days later, the mice were ...
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The double action of Cd2+ in the types and frequencies of chromosomal aberrations induced in human lymphocytes exposed to gamma rays
The presence of agents that prevent repair of DNA breaks caused by irradiation can induce more breaks than not. Cadmium is a factor that may cause DNA damage and also inactivate repair enzymes. This paper describes the investigation of chromosomal aberrations induced in human lymphocytes by the combined action of cadmium and gamma rays. Four groups were investigated: Cd alone, gamma radiation ...
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A chronic very low dose of gamma–rays alters cell adhesion
The biological effects of very low doses of ionising radiation are difficult to assess. We previously observed a delay of death by lymphoma in two different mouse strains continuously irradiated (γ–rays) with a dose rate of 10 cGy year−1. Cellular mechanisms likely to lead to slowing tumour growth were explored. Human lymphoid and epithelial cell lines (HL60 and MCF7) were irradiated in vitro at ...
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