... Title : Computational Determination of Absorbed Dose Distributions From Multiple Volumetric Gamma Ray Sources,. Corporate Author : ...

... AS INDICATORS OF ABSORBED RADIATION DOSE IN RATS. ... of doses of mixed gamma-neutron radiations or 14 ... was a function of dose over the ...

... Accession Number : ADD344981. Title : Computational Determination of Absorbed Dose Distribution From Gamma Ray Sources,. Corporate Author ...

A technique is presented for calculating the dose or energy absorbed in a material from a knowledge of the ..gamma.. radiation field and the composition of the material. The absorbed dose per unit exposure for various elements and the absorbed dose as a ...

Absorbed dose to water in a cobalt-60 gamma-ray beam has been determined using a thick-walled graphite ionization chamber. The chamber was calibrated in a graphite phantom against a graphite calorimeter, and the graphite calibration factor was converted t...

... The average absorbed dose value was 5% higher than the NRDL determination based on flux and spectrum measurements. ...

Monte Carlo calculations of the absorbed dose delivered by point source gamma emitters to tissue equivalent phantoms were performed and the results are presented in tables that include that fraction of the emitted energy absorbed by the phantom. The use of these tables makes it possible to calculate ...

A methodology has been recently developed for evaluation of doses absorbed by samples irradiated in research reactors, in which the partial doses due to thermal neutrons, epithermal neutrons, fast neutrons and gamma radiation are individually quantified. ...

The average absorbed dose and the maximum and minimum absorbed dose received by biological specimens of varying size, irradiated laterally with a known exposure dose of Co/sup 60/ gamma radiation measured in air at the midline was investigated experimentally. ...

This report documents the absorbed dose standard for photon beams in the range from 1 to 25 MeV. Measurements of absorbed dose in graphite irradiated by a beam of cobalt-60 gamma rays from an Atomic Energy of Canada Limited (AECL) E1 Dorado 6 teletherapy ...

... The system yields information on lineal energy, absorbed dose, quality factor and dose equivalent for different neutron-gamma sources. ...

This study assesses the outdoor gamma absorbed dose levels in air of the Adana's region. The measurements were taken from 130 different sample points in this area by Eberline Smart Portable (ESP-2) with SPA-6 plastic scintillation detector. The outdoor gamma absorbed dose ...

Preparation and use of ferrous sulfate-cupric sulfate dosimeters for measuring absorbed ..gamma.. and electron radiation are described. The dosimeter is suitable for accurate measurement of the absorbed dose in water irradiated with x or ..gamma.. rays or high-energy electrons. The change in ...

The determination of the degree at which ionizing radiations affect objects during radiobiological and radiation-chemical investigations, in medicine, etc., requires the knowledge of the absorbed dose. The calorimetric method is a direct method of determi...

The method presented provides a technique for calculating the absorbed dose in a material from knowledge of the radiation field, the composition of the material, and a related measurement. The procedure is applicable for x and gamma radiation, provided the energy of the photons falls in the 0.01 to 20 MeV range and the x-ray spectrum ...

The primary objective of mixed-field neutron/gamma radiation dosimetry in canine irradiation experiments conducted at the Armed Forces Radiobiology Research Institute (AFRRI) is to determine the absorbed midline tissue dose (MLT) at the region of interest...

The effects of high absorbed dose on the reusability of CaF{sub 2}:Mn thermoluminescence dosimeters (TLDs) are investigated to determine a recommended upper limit on absorbed dose for TLDs that are to be reused. This investigation examines degradation in the uniformity of response and changes in sensitivity of a ...

The frequency of chromosome aberrations in lymphocytes taken from the peripheral blood provides a useful measure of absorbed dose. The estimation of dose is affected by time in culture of the lymphocytes, by sampling error and sampling time, and by size, ...

... structures against the initial nuclear radiation produced by ... Structure Protection Coefficients (absorbed dose at receiver per unit free-field ...

Lithium-based ceramics have been proposed as tritium breeders for fusion reactors. The lithium aluminate (gamma phase) seems to be thermally and structurally stable, the damages produced by neutron irradiation depend on the absorbed dose. A method based on the measurement of neutron activation of foils through neutron capture has been ...

A standard practice is presented covering procedures for the use of thermoluminescent dosemeters to determine the absorbed dose in a material irradiated by ionizing radiation. The specific area of application is the radiation-hardness testing of electronic devices in which the material of interest is usually silicon. The method is applicable to measurement ...

The recommended practice presents a technique for calculating the dose of energy absorbed in a material from knowledge of the gamma radiation field and the composition of the material. The procedure is also applicable for x-radiation and electrons provided the effective energy of the beam is known and falls within the range from 0.10 ...

Measurements and analysis of gamma-background radiation spectrum in four different places of Qatar University campus were performed at the energy range 10 keV-3 MeV using hyper pure Ge-detector. The dependence of the detector absolute photopeak efficiency on gamma-ray energies was determined and correction of the data for that was also done. The ...

The standard method outlines a procedure for calculating the absorbed dose in a material given the material composition, the neutron fluence, and threshold-foil data related to the neutron spectrum. The method is applicable to fast-pulsed reactors of the Godiva or TRIGA type, where a substantial fraction of the neutron fluence exceeds epithermal energies ...

It is necessary during construction and subsequent operation of a commercial nuclear power reactor to evaluate the impact of the absorbed dose on the useful life of equipment and components. Routinely, the gamma contribution to this absorbed dose is evaluated, and major vendors provide ...

The preparation and use of a ceric sulfate dosimeter for accurate measurement of the absorbed dose in water irradiated with x or ..gamma.. rays or high-energy electrons are described. The ionizing radiation reduces the ceric to cerous ions, and the ceric ion concentration is measured spectrophotometrically. The method is accurate for ...

The Fricke dosimetry is used for accurate measurement of the absorbed dose in water irradiated with x- or gamma rays or high-energy electrons. The method is based on the process of oxidation of ferrous to ferric ions by ionizing radiation and can be used accurately for absorbed dose ...

Due to the Goiania radiological accident, it was necessary to develop urgently a dosimeter in order to evaluate, simultaneously, beta and gamma absorbed doses, due to /sup 137/Cs radiation. Therefore, the Dosimetric Material Production Laboratory of IPEN ...

Translated from Izmer. Tekh.; 16: No. 8, 70(Aug 1973). Errors encountered in using two ionization chambers with different hydrogen contents in the walls and gas filling for simultaneous measurement of the absorbed dose of neutrons and gamma radiation in materials are discussed. (WHK)

A theory was developed to predict the average gamma absorbed dose rates due to a continuous Gaussian plume that meanders due to variations in the wind's direction caused by large-scale eddies. Such meandering often occurs under very stable, low-wind conditions. The theory is based on Gifford's fluctuating Gaussian plume model. ...

A theory was developed to predict the average gamma absorbed dose rates due to a continuous Gaussian plume that meanders due to variations in the wind's direction caused by large-scale eddies. Such meandering often occurs under very stable, low-wind conditions. The theory is based on Gifford's fluctuating Gaussian ...

The question of estimating an integral dose of secondary radiation in the body, originating as the result of interaction between the primary x rays and gamma rays with the ground substance is discussed. The proposed method of computation enables it to approximately estimate both the total integral dose in the whole of the body ...

A study on the effect of gamma radiation dose and dose rate on the yield of copper nanoparticles produced had been done. Its objective is to show the relationship between the absorbed doses with the yield of production. The copper sulphate solution is prepared with addition of ethanol as ...

The effects of gamma radiation on Methylene Blue, Fluorescein, Rhodamine B, Fast Red S, and Brilliant Green dyes absorbed in Corning thirsty glass (code 7930) are presented. The optical absorbency follows Beer's law with radiation dose to 10/sup 9/ erg gm/sup -1/ carbon. The absorption of dyes in ...

Calculations have been made of the incident neutron and gamma-ray absorbed dose response as a function of energy in the mid-head position of a phantom model. The calculations were performed with the DOT discrete ordinates transport code in the adjoint mod...

No accepted official protocol exists for the dosimetry of the Leksell Gamma Knife (GK) stereotactic radiosurgery device. Establishment of a dosimetry protocol has been complicated by the unique partial-hemisphere arrangement of 201 individual 60Co beams simultaneously focused on the treatment volume and by the rigid geometry of the GK unit itself. This article proposes an air ...

Dose calculations for neutron therapy irradiations should be based on the dosimetrically best accessible parameters "total absorbed Dose Dt" and "gamma ray absorbed dose Dgamma". By adequate standardization it should be possible, that only one single reference parameter ...

Ceric sulfate dosimetry is used for accurate measurement of the absorbed dose in water irradiated with x- or gamma-rays or high-energy electrons. It is based on the process of reduction of ceric to cerous ions by ionizing radiation. The method is most accurate for absorbed doses in the range ...

The absorbed dose in the liver, spleen and bone marrow of Thorotrast patients was estimated for 71 autopsy cases. 232Th amounts in tissues were determined from measurements of 228Ac gamma-rays and the activity ratio of 228Ac to 232Th. In calculating the absorbed dose, Kaul's data were used as ...

The primary objective of mixed-field neutron/gamma radiation dosimetry in canine irradiation experiments conducted at the Armed Forces Radiobiology Research Institute (AFRRI) is to determine the absorbed midline tissue dose (MLT) at the region of interest in the canine. A dose conversion factor (DCF) can be applied ...

The gamma-ray altimeter, containing a gamma-radioactive source 137Cs with activity of 2.96 x 10(10) Bq, was used to detect the height of the spacecraft recovery capsule during landing. To measure the gamma-dose distribution near to the guidance section, especially at position where the useful load is located in recovery capsule, ...

Six persons were accidentally exposed to gamma rays from an /sup 192/Ir source. Since they were non-occupational persons, a means to estimate the absorbed dose was needed to be established. As three of them wore wrist watches when they were exposed to gamma rays from the /sup 192/Ir source, cumulative ...

Epidemiological studies on uranium miners are being carried out to quantify the risk of cancer based on organ dose calculations. Mathematical models have been applied to calculate the annual absorbed doses to regions of the lung, red bone marrow, liver, kidney and stomach for each individual miner arising from exposure to radon gas, ...

The effects of low doses of x radiation on the concentration of gamma globulins in blood and protein complexes absorbed on zymosan in chickens were investigated. Studies demonstrated that low doses of ionizing radiation enhanced the bactericidal properties and virus neutralizing properties of blood serum.

Commercial and speeral glass samples are used for high dose dosimetry in gamma rays of a 110 kG cobalt-60 irradiation facility. The correlation between absorbed doses and optical desities of the sample was studied. Calibration curves were obtained by usin...

A systematic study of isodose distributions and dose uniformity in sample carriers of the Portuguese Gamma Irradiation Facility was carried out using the MCNP code. The absorbed dose rate, gamma flux per energy interval and average gamma energy were calculated. For ...

A method to calculate absorbed doses at depths in the walls of a static spherical bladder from a positron emitter in the bladder content has been developed. The beta ray dose component is calculated for a spherical model by employing the solutions to the integration of Loevinger and Bochkarev point source functions over line segments ...

An attempt has been made to estimate the absorbed dose rate using both theoretical and measured mass energy attenuation coefficient of gamma for the lead compounds such as PbNO3, PbCl2, PbO2 and PbO using various gamma sources such as 22Na (511, 1274), 137Cs (661.6), 54Mn (835) and 60Co (1173, 1332 keV).

Radioactive skin contamination with {beta}- and {gamma}-emitting radionuclides may result in biologically significant absorbed doses to the skin. A specific exposure scenario of interest is a nonuniform skin dose delivered by {beta}- and {gamma}-emissions from radioactive skin contamination. ...

The results obtained from more than 1000 indoor and outdoor in situ gamma spectrometry measurements in 41 towns (from all geographic subdivisions) of the Greek mainland (not islands) are presented. From the in situ gamma spectra the absorbed dose rate in air due to uranium series, thorium series, 40K and 137Cs are ...

A method for calibrating an ion chamber in terms of absorbed dose is given which avoids the need for corrections for attenuation. The absorbed dose is measured using a carbon calorimeter, a carbon chamber, and a BaldwinFarmer chamber. The method was used with x-ray beams at 4 to 20 Mv and Co/sup 60/ ...

The results obtained from 259 indoor and outdoor in situ gamma spectrometry measurements with a portable Ge detector and 707 total gamma dose rate measurements with an NaI detector in urban areas of 16 Greek islands are presented. From the in situ gamma spectra, the absorbed ...

... Accession Number : AD0672563. Title : A CALORIMETER WITH INTERCHANGEABLE ABSORBERS FOR ABSORBED DOSE ...

... Title : MODELS FOR ESTIMATING THE ABSORBED DOSE FROM ASSIMILATION OF RADIONUCLIDES IN BODY ORGANS OF HUMANS,. ...

Dose reconstruction for citizens of Belarus affected by the Chernobyl accident showed an unexpectedly wide range of doses. Using the EPR tooth enamel dosimetry method, it has been demonstrated that when the tooth enamel dose was formed due to x-rays with effective energy of 34 keV and the additional irradiation of enamel samples was ...

The standard fluence-to-dose conversion factors in ANSI/ANS-6.1.1-1977 are based on a so-called dose equivalent (DE) formula, where the absorbed dose is modified by a quality factor, Q, which is equal to 1 for gamma rays and varies from 1 to 20 for neutro...

A dosimetric study of Thorotrast is described. Steady state activity ratios and self-absorptions of ..cap alpha..-particles in the /sup 232/ThO/sub 2/ aggregates were determined by ..cap alpha..- and ..gamma..-ray spectrometry. By using these results, the absorbed doses in 39 autopsy cases were estimated and compared with German data. ...

A new standard, expressed in terms of absorbed dose at a depth of 5g/cm/sup 2/ in a water phantom irradiated by cobalt 60 gamma photons, is determined. The procedure developed is based on a transfer method using two dosimetric techniques: Fricke dosimetry...

Equations and tabular data are presented for calculating the absorbed dose in rads when the field conditions of expcsure to radiation are known. The elements considered here are those most commonly found in low-Z organic materials, such as plastics, elastomers. lubricants, and insulating materials. The types of radiation considered are ...

Ferrous-cupric sulfate dosimetry is used for accurate measurement of the absorbed dose in water irradiated with x- or gamma-rays or high-energy electrons. It is based on the process of oxidation of ferrous to ferric ions by ionizing radiation. The method is most accurate for absorbed doses in ...

Models for estimating the absorbed dose due to an atmospheric release of radionuclides are required for the siting of, operations of, and emergency planning for nuclear facilities. In the early days of nuclear power reactors, emphasis was on the long-term dose from routine release. Currently there is interest in models to estimate the ...

A survey of the geochemical literature and unpublished data has resulted in the classification of the concentrations of the naturally occurring radioelements U, Th, and K by their associated rock types. A data base of over 2500 entries has been compiled, permitting calculation of terrestrial gamma-ray absorbed dose rates. The general ...

A survey of the geochemical literature and unpublished data has resulted in the classification of the concentrations of the naturally occurring radioelements U, Th, and K by their associated rock types. A data base of over 2500 entries has been compiled, permitting calculation of terrestrial gamma-ray absorbed dose rates. The general ...

The development of a calorimetric technique for the determination of the intensity of radiation has been previously reported. This method has been further developed and applied to the measurement of locally absorbed dose. Its use for the determination of the absorbed dose produced in tissue-equivalent ...

The natural radioactivity of some building materials commonly used in Cuba was measured by gamma spectrometry. Typical concentrations encountered so far encountered are in the ranges: 47-2511 Bq kg(-1) for (40)K; 9-71 Bq kg(-1) for (226)Ra; and 2-38 Bq kg(-1) for (232)Th. The external gamma ray absorbed doses in ...

We have examined the inherent fluorescence of pepper and cinnamon samples exposed to radiation from a 60Co gamma source. We find that in the pepper the fluorescence intensity increases with radiation dose and the ratio of fluorescence intensity at two specific wavelengths, 566 and 674 nm, increases with radiation dose. In contrast, in ...

This invention relates generally to nuclear radiation dosimetry, and more particularly to a radiochromic leuko dye dosimeter constructed and arranged to measure absorbed radiation doses, such as gamma rays, X-rays and fast neutrons, in real time; viz., as...

The method for determination of the dose rate absorbed by tissue for JINR phasotron medical proton beams on a basis of clinical dosimeter calibration with the (sup 60) Co (gamma)-source, the main parameters of detectors used for measurements of spatial do...

The absolute measurements of main dosimetric parameters in the /sup 60/Co field of ROKUS irradiation device are performed in order to create a standard irradiation field for calibration of medical dosemeters. The measurements were made by means of tissue-...

Studies reported herein have shown that a treatment of 55 exp 0 C for 1 hour or more sufficiently reduces the number of viable Ascaris eggs in seeded sludge systems. An absorbed dose of 300 kilorads gamma radiation is more than adequate for the same purpo...

Between September 1974 and December 1977 the National Bureau of Standards, in cooperation with the Bureau of Radiological Health, performed a study of the accuracy with which a prescribed absorbed dose of cobalt-60 gamma radiation is delivered to a specif...

units of R/Hr. For gamma radiation, this is roughly equivalent to a radiation absorbed dose rate in units of cGy/hour, which must also take into account any shielding present,...

...absorbed dose in soft tissue of 20 rads of combined neutron and gamma radiation at an unshielded distance of 2 meters from the reacting material...minute. Coverage of all monitored areas must be provided by two...

Presented at Sixth Tripartite Instrumentation Conference, Chalk River, Canada, April 1959. The measurement of absorbed integrated'' gamma dose in a reactor field presents abundance of complex problems. Several aspects of what seems to be the most immediate of these problems are presented. (W.L.H.)

Polyvinyl alcohol films containing congo red are useful as gamma and electron radiation dosimeters. Absorbed doses should not exceed 500 kGy. The dose response is rather linear in a higher range, e.g., 100 to 500 kGy. The film is relatively stable before and after irradiation for quite a long time against fading, ...

A mathematic model for evaluation of absorbed dose in radionuclide renography has been developed and programmed for automatic calculation in the computer. Input data to the model are readily available from the results of the renography and, hence, the method described is suitable for individual dose determinations in adults. Apart from ...

A mathematic model for evaluation of absorbed dose in radionuclide renography has been developed and programmed for automatic calculation in the computer. Input data to the model are readily available from the results of the renography and, hence, the method described is suitable for individual dose determinations in adults. Apart from ...

Accurate estimate of absorbed dose to target tumors and normal tissues in the body is an important requirement for establishing fundamental dose-response relationships for radioimmunotherapy. Two major obstacles have been the difficulty in obtaining an accurate patient-specific 3-D activity map in-vivo and calculating the resulting ...

The aim of the present study was to investigate of a possible correlation between indoor radon and indoor gamma dose rates deduced by in situ gamma spectrometry measurements by using a portable HPGe detector. Indoor radon and high resolution in situ gamma spectrometry measurements were performed in 60 apartments in ...

To evaluate neutron and gamma-ray absorbed doses in human bodies at criticality accidents, two kinds of tissue-equivalent dosimeters, a polymer-alanine dosimeter and a thermoluminescent dosimeter (TLD) made of {sup 7}Li{sub 2}{sup 11}B{sub 4}O{sub 7}, were applied to dosimetry experiments with {approx}10% enriched uranyl nitrate ...

With consideration of the special requirements which are placed on the measuremert method in gamma radiation measure ments in shut-down reactors, the selection or a suitable measurement method is discussed. The operation and properties of glass dosimeters are described. The calibration curves resulting from the measuremeats including the calibration errors arising ...

Determination of the radiation dose delivered to electronic devices and components exposed to radiation environments is basic to the assessment of system's vulnerability and hardening. In the region of the interface between materials of different composition, the radiation dose can be more than ten times that obtained by applying standard experimental or ...

External gamma irradiation of dogs with doses of 103.2 and 51.6 mC/kg combined with the effect of inhaled plutonium-239 accelerates the formation of absorbed doses in secondary organs of the radionuclide deposition by 41.7 and 2.4 times, respectively, whereas the dose of 25.8 mC/kg is ...

The dual dosimeter technique for determining both the absorbed dose of neutrons and photons in a mixed field has been applied to multiple dosimeter use. The data were analyzed by a linear regression method which yields the neutron dose from the slope and the photon dose from the intercept and an estimation of the ...

The aim of this work is to elaborate a computer code based on Monte-Carlo method for simulating the gamma rays - matter interactions, in order to evaluate doses absorbed by some biological samples. This code can be used in agricultural field as well as in...

First, attention is drawn to the fundamental definitions of force, weight, mass, work, energy, power, and the pertinent units of measurements in the cgs system. Panticularly attention is given to the eng and its relation with ev and Mev units, the mechanical equivalent of calories, and the unit of absorbed dose, the rad. In the second part the ...

Irradiation of blood products abrogates the proliferation of lymphocytes present in cellular component, which is currently the only accepted methodology to prevent transfusion-associated graft versus host disease (TA-GVHD). A range of irradiation dose levels between 15 Gy and 50 Gy is being used, but the majority of facilities are employing 15 Gy. It should, however, be ...

Radiochromic Dye Dosimeters (Gafchromic DM-100) were used to measure the absorbed doses in liquid samples exposed to a {sup 137}Cs gamma-ray source. The initial calibration of commercially available radiochromic film was performed using a {sup 60}Co gamma-ray source. When exposed to gamma-ray ...

Gamma sources are usually prepared by arranging the radioactive preparation alongside the generatrix of a hollow cylinder; determination of the distribution of the dose absorbed by a cylindrical body from such source is of great interest. Solution of this problem was carried out on the basis of assumptions published by the ...

A series of dosimetric measurements was carried out at the Antoni van Leeuwenhoek Hospital, Amsterdam, using a Philips d + T generator, which produced neutrons with energies of approximately 14 MeV. A-150 plastic ionization chambers, an A-150 plastic calorimeter, and a GM dosimeter were used to determine total absorbed dose and the photon ...

An irradiation experiment on insulation gas was carried out to evaluate ionization current and voltage holding characteristics with the gamma-rays from Co-60. The gases of air, SF{sub 6}, C{sub 2}F{sub 6}, CO{sub 2}, and mixture of air and SF{sub 6} were investigated using parallel-disk electrodes all the absorbed dose rate of up to ...

Effects of gamma radiation on indigenous strong cation and anion exchange resins have been studied in HCl medium up to a dosage of 3600 kGy. The ion exchange capacities of cation and anion exchangers decreased by around 20% at 2400 kGy of absorbed dose. Decrease in salt-splitting capacity and total exchange capacity for both cation and ...

A series of dosimetric measurements was carried out at the Antoni van Leeuwenhoek Hospital, Amsterdam, using a Philips d+T generator, which produces neutrons with energies of approximately 14 MeV. A-150 plastic ionization chambers, an A-150 plastic calorimeter, and a GM dosimeter were used to determine total absorbed dose and the photon ...

The average outdoor absorbed dose rate in air and the average annual effective dose equivalent due to terrestrial gamma radiation from 40K, 238U and 232Th in rocks in Ondo and Ekiti States, Southwestern Nigeria have been evaluated from measurements of the concentrations of these radionuclides in this environmental ...

Design and construction of an absorbed-dose calorimeter fabricated of pure carbon were completed. Measurements of the absorbed dose in carbon from a Co/sup 60/ gamma-ray beam and from 250 and 150 Kvcp x rays were completed. Parallel chemical and-ionization measurements were made for these radiations. The ...

Exact two-dimensional and asymptotic one-dimensional integral solutions were obtained for the external dose rate value due to a Gaussian plume. The relative error of the asymptotic solution was found to be less than 5% for downwind distances of 1 to 300 mean free path lengths and for crosswind distances of 0 to 40 mean free path lengths. A good agreement was observed with the ...

Analysis of the relationship of the incidence of leukemia to gamma and neutron dose among atomic bomb survivors until 1971 has been reported previously by RERF. The present inquiry was prompted by the extension of case finding to 1978 and by the recent av...

The absorbed gamma-dose rate in air at a height of 1 m above ground level was calculated from activity concentrations of gamma-emitting radionuclides in arable soil samples collected from eight locations within Sinnar State using the published Dose Rate Conversion Factors. Measurements were carried out using ...

The radiation absorbed doses from five commercially available hepatobiliary agents-Tc-99m-tagged analogs of IDA (EIDA, PIPIDA, HIDA, PBIDA, DISIDA*) have been calculated from biokinetic data in 41 normal subjects. Serial gamma images, with blood and urine samples, were obtained to calculate cumulated radioactivity in the source organs: ...

The radiation absorbed doses from five commercially available hepatobiliary agents--/sup 99m/Tc-tagged analogs of IDA (EIDA, PIPIDA, HIDA, PBIDA, DISIDA) have been calculated from biokinetic data in 41 normal subjects. Serial gamma images, with blood and urine samples, were obtained to calculate cumulated radioactivity in the source ...

The effect of irradiation temperature and absorbed dose on cross-linking and destruction of butadiene-nitrile (BDN) and fluoro rubbers and their vulcanizates in the nondeformed and strained state was studied. Irradiation of BDN and its vulcanizates with low absorbed doses caused a simultaneous rupture of ...

When there is an absence of scattering material adjacent to the skin on the exit side of a megavoltage beam the dose to the skin is less than would be calculated using depth dose tables or isodose distributions measured in ''semi-infinite'' phantoms. Ionization measurements using a thin-window parallel-plate chamber show ...

The radiation-induced UV-vis spectrum of /?-terthiophene radical cation in solid is reported. The radical cation initiates an oligomerization in the CTA matrix producing permanently coloured conjugated polarons. The specific net absorbance at 465nm is linearly related with dose up to 2�106Gy, for electrons and gamma irradiation. The ...

The energy absorbed by aluminum, carbon, or tissueequivalent (TE) material when exposed to gamma rays, fast neutrons, or 900-Mev alpha particles was measured with a microcalorimeter. The instrument was patterned after the one described by Reid and Johns, Rad. Res. 14: Spaced mylar sheets about 6-1/2 in. in diameter were mounted on one side of ...

In the case of the deposition of alpha - and BETA -active aerosols in the respiratory system, the activity of the live subject usually cannot be directly determined and only the concentration of the aerosol in the air is measured. Calculation of the average holdup time in the system from such data often leads to erroneous values. It was previously reported That from the alpha -, ...

The National Bureau of Standards is performing a study of the ability of radiation-therapy departments to deliver prescribed absorbed doses of /sup 60/Co gamma radiation to a water phantom. Batches of thermoluminescence dosimeters are mailed to participating therapy departments for irradiation under prescribed conditions. Upon return ...

Incidence and mortality from cerebrovascular diseases (CVD) (430-438 ICD-9 codes) have been studied in a cohort of 18,763 workers first employed at the Mayak Production Association (Mayak PA) in 1948-1972 and followed up to the end of 2005. Some of the workers were exposed to external gamma-rays only while others were exposed to a mixture of external ...

A systematic study was performed on the influence of the high dose gamma radiation on the kinetics of etching and the registration threshold of some plastic track detectors, like cellulose nitrate, polycarbonate and polyethyleneterephthalate. An important acceleration of the etching was observed at an absorbed ...

Experiments were carried out on the irradiation of aqueous solution of polyvinvl alcohol by gamma rays. For sufficient dose of radiaiion, the polymer molecules in the solution interlinked with each other and formed an insoluble gel. The change in degree of polymerization of the polymer with the absorbed ...

The absorbed gamma dose rate in air 1 m above soil due to natural gamma emitters and {sup 137}Cs from the Chernobyl accident was determined inside a Quercus conferta Kit ecosystem in Northern Greece by combination of Monte Carlo simulations with the MNP code and in-situ gamma spectrometry ...

The distribution of steady-state and pulsed neutron and gamma-ray dose was measured in an animal exposure volume at the TRIGA reactor. The usable volume was restricted to the lower 20 in. of an aluminum irradiation tube having an ID of 9.5 in. The tube was inserted into the pool adjacent to the reactor void tank, 134 cm from the core. Dosimetry ...

The activity concentrations and absorbed gamma dose rates due to primordial radionuclides and (137)Cs have been ascertained in 222 soil samples in 18 counties of the Trabzon province of Turkey using a HPGe detector. The mean activity concentrations of (238)U, (232)Th, (40)K and (137)Cs in soil samples were 41, 35, 437 and 21 Bq kg(-1), ...

Several legacy hydraulic oil waste streams contaminated with Aroclor 1260 and small amounts of Cesium-137 have been in storage at the Idaho National Engineering Laboratory (INEL) due to the lack of appropriate treatment facilities. The goal of this study was to demonstrate that polychlorinated biphenyls (PCBs) could be selectively decomposed in the oils. Removal of the PCB component to less than ...

Observations over a 3-yr period are reported on the blood picture in dogs exposed to chronic low-level gamma radiation, chronic low doses of Sr/sup 90/, and the combined effects of chronic external gamma exposure and internal Sr/sup 90/. All radiation doses were less than two orders higher than the ...

This work is devoted to the application of high-resolution gamma-ray spectrometry in the study of the effective dose coming from naturally occurring radionuclides, namely 40K, 232Th and 238U, present in building materials such as sand, cement, and granitic gravel. Four models were applied to estimate the effective dose and the hazard ...

Depth dose distributions for a d(14)Be neutron beam, measured separately for total and gamma absorbed dose, are presented for nine tissue substitutes and for two field sizes. These data are used to examine methods to transform depth dose curves from one material to another. Best results are ...

The activity and gamma-absorbed dose rate due to the naturally occurring radionuclides in the terrestrial environment such as (238)U, (232)Th and (40)K were determined in soil and rock samples collected around Kakrapar Atomic Power Plant site, using gamma-ray spectrometry. The mean concentration levels measured in Kakrapar soil from ...

Tissue equivalent gel phantoms have been widely studied in radiation therapy for both relative and reference dosimetry. A Fricke xylenol gel (FXG) spherical phantom was evaluated by means of magnetic resonance image method (MRI) to measure absorbed dose distribution resulted from gamma knife irradiation. The FXG phantom was prepared ...

The absorbed dose primary standard of the BEV is a graphite calorimeter. Two methods are employed for the conversion of absorbed dose to graphite into absorbed dose to water: calculation on the one hand and the use of an ionization chamber in combination ...

The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit w...

This work describes an algorithm for absorbed dose evaluation in the region of X-ray diagnostic energy based on the response of CaSO(4):Dy thermoluminescence powder detectors. The absorbed dose was calculated using Monte Carlo simulation code (MCSC) and then compared to the experimental TLD results for X-rays ...

As part of a collaborative project between the National Research Council of Canada (NRC) and the Swiss Federal Office of Metrology and Accreditation (METAS), a sealed water calorimeter was built at NRC and transferred to METAS. The calorimeter is operated at 4 degrees C and uses two thermistor probes in a sealed glass vessel containing high-purity water to measure the radiation-induced temperature ...

This study was carried out to evaluate the effect of gamma irradiation on the physical and structural properties of ?-glucan. ?-Glucan solution (10%, w/v) was exposed to a cobalt-60 source (10, 30, and 50 kGy). Gel permeation chromatography data showed that the average molecular weight of irradiated ?-glucan significantly decreased as the irradiation dose ...

The primary objective of this work was to estimate the absorbed dose distribution to the bone marrow of six multiple myeloma patients who received holmium-166 (166Ho) DOTMP (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene-phosphonic acid) for the purpose of bone marrow ablation. A methodology based on gamma camera images was ...

A study was made of the variations undergone by the binding constants of ..gamma..-irradiated DNA-9-Aminoacridine complexes. It was observed that the binding constants of the different complexes at first increase according to the absorbed dose, then decrease. This feature is presumably due to the succession of events occurring in the ...

Clinoptilolite was found to possess the structural stability to irradiation which is characteristic of other silicates. No effect of gamma irradiation on the mineral was detected by x-ray diffraction, differential thermal analysis, or distribution coefficient determinations up to an exposure of 9.6 x 10/sup 9/ r (8.4 x 10/sup 9/ rad absorbed ...

The initial yield of molecular H in gamma -irradiated aqueous solutions was measured as a function of acidity in the range from neutral to 10M H/sub 2/SO/ sub 4/. A decrease in H yield with increasing acidity was observed. It was concluded that the gross number of radicals formed per unit absorbed dose is independent of pH. ...

The main dosimetric characteristics of amethyst, Brazilian natural semi-precious stone, were investigated in this work, in order to verify the possibility of its use for gamma-radiation detection using the thermoluminescent (TL) technique. The samples were tested in X- and gamma-radiation beams, and their TL glow curves, dependences of the response on the ...

The natural radioactivity of some building materials used in cities of Darkhan, Ulaanbaatar and Erdenet in Mongolia was measured by gamma-ray spectrometry with HP-Ge-detector. The radium equivalent concentration and the gamma absorbed dose rate in air, were estimated as the external and internal hazard indices. The ...

Data were obtained on the dependence of the index of refraction (ir) of aqueous solutions of acrylamide on the absorbed dose of /sup 60/Co /gamma/-radiation. The calculated data on the dependence of ir on the degree of polymerization are reported. Using calculations of polymer models and the IR spectra, it was shown that the increase ...

Chloroaluminum phthalocyanine (ClAlPc) synthesized by adopting focused microwave synthesis approach was doped with nanocrystalline TiO2 (5% by weight) and developed into the thin film sandwiched device having ITO/ClAlPc:TiO2/Ag Schottky configuration by spin coating technique covering 1 cm2 as an active area. The so fabricated device having initial dark current of the order of 0.2 5 m A was ...