International Nuclear Information System (INIS)

First, absorbed dose at entrance surface was measured in routine mammography. Secondly, a possibility of dose reduction after introduction of Fuji computed radiography (FCR) system was examined. In a total of 350 mammographic studies including craniocaudal and medilateral projections, average thickness of compressed breast was less than 4 cm and most frequently recorded absorbed dose was 0.2-0.3 cGy (200-300 mrad). Minimum dose to obtain clinically acceptable mammograms in FCR system was estimated by comparing image quality of routine versus reduced dose studies. It was concluded that absorbed dose could be reduced to 1/4 of routine dose without creating significant drawback in diagnosis. (author).

International Nuclear Information System (INIS)

A method has been developed for calibration of CT-numbers to volumetric electron density distributions using tissue substitutes of known elemental composition and experimentally determined electron density. This information have been used in a dose calculation method based on photon and electron interaction processes. The method utilizes a convolution integral between the photon fluence matrix and dose distribution kernels. Inhomogeneous media are accounted for using the theorems of Fano and O'Connor for scaling dose distribution kernels in proportion to electron density. For clinical application of a calculated dose plan, a method for prediction of accelerator output have been developed. The methods gives the number of monitor units that has to be given to obtain a certain absorbed dose to a point inside an irregular, inhomogeneous object. The method for ...

British Library Electronic Table of Contents (United Kingdom)

Purpose Study the radiolysis of solid-state metoclopramide hydrochloride at various absorbed doses. Elucidate the structure of the degradation products to gain information on the radiolysis mechanisms. Methods Solid-state metoclopramide samples were irradiated at several doses with gamma rays and high-energy electrons to evaluate the influence of the dose rate. High-performance liquid chromatography with a diode array detector was used to measure the chemical potency as a function of the absorbed dose and to quantify the degradation products. The characterization of degradation products was performed by liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Results The degradation of solid-state metoclopramide after irradiation was negligible. No qualitati...

International Nuclear Information System (INIS)

Wood-polymer composites (WPC) have been prepared of pinewood with different monomers using Gamma radiation: acrylamide, butyl acrylate, butyl methacrylate, styrene, acrylonitrile, and polyester. The polymer loading was determined as a function of monomer concentration and absorbed dose. The data show that polymer loading increases by increasing the monomer concentration. In two cases, BMA and polyester, the polymer loading decreases at high concentrations. This can be explained by the increase of the viscosity. Thus the diffusion of the compound into bulk would be slower. The absorbed dose seems to play a positive role in enhancing the polymer loading by increasing the dose. The mechanical properties, tensile and compression strength, have been improved in the most cases for all monomer concentrations or absorbed doses. Using polyester there ...

International Nuclear Information System (INIS)

Building on the concepts of MIRD methods described by Webber, Watson and others at this Symposium on the Dosimetry of Administered Radionuclides, we will now consider how to apply these principles to several experimentally based open-quote macroclose quotes and multicellular models. Specifically, methods to calculate absorbed dose using different types of particulate emission (alpha, beta) with a variety of antibody carriers (IgG, F(ab')_2, Fab) for radioimmunotherapy (RIT) will be reviewed. Additionally, a discussion of direct measurement methods at the multicellular level will reveal the problems of tumor absorbed dose heterogeneity when applied to animal and clinical studies.

Energy Technology Data Exchange (ETDEWEB)

The performance of PAN-based composite absorbers was evaluated in dynamic experiments at flow rates ranging from 25--100 bed volumes (BV) per hour. Composite absorbers with active components of ammonium molybdophosphate (AMP) PAN and K-Co ferrocyanide (KCoFC) PAN were used for separating Cs from a 1 M HNO{sub 3} + 1 M NaNO{sub 3} + 2 {times} 10{sup {minus}5} M CsCl acidic simulant solution. KCoFC-PAN and two other FC-based composite absorbers were tested for separating Cs from alkaline simulant solutions containing 0.01 M to 1 M NaOH and 1 M NaNO{sub 3} + x {times} 10{sup {minus}4} M CsCl. The efficiency of the Cs sorption on the AMP-PAN absorber from acidic simulant solutions was negatively influenced by the dissolution of the AMP active component. At flow rates of 50 BV/hr, the decontamination factor of about 10{sup 3} could be maintained for treatment of 380 BV of the feed. With the KCoFC-PAN ...

International Nuclear Information System (INIS)

The purpose of this study is to evaluate the accuracy of dose calculations by three algorithms. Depth dose, OPF (Output Factor) and dose profiles were measured in a heterogeneous phantom. These values were also calculated by three algorithms of the Batho power law (BPL), Equivalent-Tissue Air Ratio (ETAR) and Convolution superposition (CS). The data were obtained for 4, 6 and 10 MV photon beams with a linear accelerator (Varian 21EX). Field size ranged from 3 x 3 cm"2 to 10 x 10 cm"2. Dose profiles of beam penumbra were also measured by a 0.125 ml ionization chamber at the point of 8, 13 and 18 cm from the surface of the phantom at intervals of 1 mm. Differences between measured and calculated depth doses were within 2% in BPL and CS, but depth doses were overestimated in ETAR. OPFs were also overestimated with the error of more than 4% in ETAR. ...

International Nuclear Information System (INIS)

A calculation method of the X-ray radiation dose (energy of gamma- radiation remains in the range of energies where the mechanism of photoelectric absorption is the prevailing one) absorbed in the absorbers of final thickness is suggested. Calculations of resorption of secondary radiation (characteristic fluorescences) in the substance and kinetic energy of photoelectrons caused by this resorption (it would be enough to consider one or two hard series) are presented. Calculation of the spectrum of photoelectron energy yield in TeInSe_2 monocrystal for 0.1-0.5 A range of X-ray radiation is conducted by the developed methods.

International Nuclear Information System (INIS)

Ionizing radiations that differ in number, size, and distribution of energy deposition events might be expected to cause different effects for the same absorbed dose. Furthermore, microdosimetry calculations suggest that large variations in biological effectiveness might be expected for internally deposited alpha-emitting radionuclides for the same absorbed dose, depending upon the specific activity and spatial distribution of the sources in tissue. The study described in this article was designed to demonstrate these phenomena in vitro. Cultured Chinese hamster ovary (CHO-K1 BH4) cells were exposed in vitro to inert, insoluble ceramic microspheres in zirconium dioxide labeled with "2"3"9Pu. The average exit energy of the 5.15 MeV alpha particle was calculated to be 4.3 MeV. Exposure times varied from four to seven hours to achieve the desired dose level.

International Nuclear Information System (INIS)

Carcinogenesis is now generally recognized to be an important detrimental effect in man after low dose irradiation. The carcinogenic action of ionizing radiation is clearly demonstrated after exposure to relatively high doses (in excess of 0.5 Gy) but for lower dose levels reliable direct observations are not available. With the introduction of special protocols for the performance of large scale screening programs by mammography the average absorbed dose in glandular tissue in the average breast can be restricted to a value of 3 mGy per mammogram. The risk for tumor induction after exposure to these low doses can never be established from human epidemiology. In order to investigate the risk of repeated exposure to small dose of ionizing radiation the induction of mammary tumors has been investigated in rats of the WAG/Rij strain after ...

International Nuclear Information System (INIS)

It needs accurate estimation of radiation level for verifying machinery and cable in Nuclear Power Plant. Therefore, in this study, we used ESR(Electron Spin Resonance) system for estimate dose of Alanine dosimeter. Alanine/ESR dosimetry, already known as a dosimetric method in medical and industrial field, was applied to estimate dose quantity at cable locations within a nuclear power plant as a part of equipment qualification program. Alanine/ESR dosimetry of absorbed dose range is 1 - 100 KGy. The alanine dosimeter is not significantly affected by temperature and fading is limited to 1% per year. The alanine dosimeters were fixed on the targeted cable or nearest position to measure dose quantity to get accurate value. Alanine dosimeters were scanned by commercially used two different ESR systems, e-scan and EMX series for alanine dosimeters. To estimate more accurate ...

International Nuclear Information System (INIS)

A method for calculation of absorbed dose distributions in three dimensions for 1-20 MeV photons is presented. The method uses convolution/superposition of photon fluence distributions with energy scattering kernels. Results for Co-60 and X-ray beams in homogeneous and inhomogeneous media are compared with measurements. Good agreement is found between calculations and measurements. 8 refs.; 3 figs.

CERN Document Server

Dimensional metrology and positioning operations are used in many fields of particle accelerator projects. This lecture gives the basic tools to designers in the field of measure by analysing the spatial layout of measurement systems since it is central to dimensional metrology as well as positioning operations. In a second part, a case study dedicated to a synchrotron storage ring is proposed from the detection of the magnetic centre of quadrupoles to the orbit definition of the ring.

International Nuclear Information System (INIS)

Thermoluminescence (TL) dosimetry was used to measure dose effects on the raw stock material of borosilicate container glass from different geographical locations. Effects were studied at times up to 60 days post-irradiation at doses from 0.15 to 20 Gy. The minimum detectable dose using this technique was estimated to be 0.15 Gy which is roughly equivalent to a 24 hr irradiation 1 cm from a 50 ng source of 60Co. Two peaks were identified in the TL glow curve, a relatively unstable peak around 125 C and a more stable peak around 225 C. Differences in TL glow curve shape and intensity were also observed for the glasses from different geographical origins. We investigate radiation induced defects in glass to further develop the technique of intrinsic dosimetry - the measurement of the total absorbed dose received by the walls of a container holding radioactive material. Intrinsic ...

Energy Technology Data Exchange (ETDEWEB)

To date, no single passive detector has been found that measures dose equivalent from ionizing radiation exposure in low-Earth orbit. We have developed the I.S.S. Passive Dosimetry System (P.D.S.), utilizing a combination of TLD in the form of the self-contained Pille TLD system and stacks of CR-39 plastic nuclear track detector (P.N.T.D.) oriented in three mutually orthogonal directions, to measure total dose and dose equivalent aboard the International Space Station (I.S.S.). The Pille TLD system, consisting on an on board reader and a large number of Ca{sub 2}SO{sub 4}:Dy TLD cells, is used to measure absorbed dose. The Pille TLD cells are read out and annealed by the I.S.S. crew on orbit, such that dose information for any time period or condition, e.g. for E.V.A. or following a solar particle event, is immediately available. Near-tissue equivalent CR-39 ...

International Nuclear Information System (INIS)

Techniques for reducing computation time in 3D photon dose calculations are addressed with specific emphasis given to the convolution/superposition approach. A single polyenergetic superposition model calculating absorbed dose per incident photon fluence (Gy cm"2) was developed in terms of TERMA and a total energy deposition kernel (a total point spread function). A novel approach was devised for reducing calculation time. The method, named the CF method, was based on the use of a conventional, fast model (here a modified power-law method was used) for the generation of 3D dose distributions on a fine dose matrix. Superposition calculations were carried out on a coarse matrix and calculation speed was increased simply by reducing the number of calculations. A set of correction factors was derived on the coarse grid from the ratio of the dose values from ...

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The importance of cellular dosimetry in both diagnostic and therapeutic nuclear medicine is becoming increasingly recognized. Experimental range-energy relations for electrons and alpha particles, along with derived geometric reduction factors, are used to calculate cellular absorbed fractions for these radiations. The resulting absorbed fractions are employed to calculate cellular S-values for several radionuclides. Cellular absorbed fractions for monoenergetic electron sources with energies ranging from 0.1 keV to 1 MeV, distributed uniformly in the source region, are calculated for several target {l_arrow} source combinations including cell{l_arrow}cell, cell{l_arrow}cell surface, nucleus{l_arrow}nucleus, nucleus {l_arrow}cytoplasm and nucleus {l_arrow}cell surface. Similar data are also provided for monoenergetic alpha particle sources with energies ranging from 3 to 10 MeV. S-values are also conveniently tabulated for ...

International Nuclear Information System (INIS)

Radon concentration measurements were carried out using solid-state nuclear track-etch detectors (SSNTDs) type CA 80-15 cellulose nitrate films, in a Pleistocenic cave at Petralona, in Halkidiki, Northern Greece, at 55 km from the city of Thessaloniki. Radon levels as high as 88 kBqxm"-"3 (2.38 nCi x l"-"1) have been recorded inside the cave equivalent to 11.90 WL in terms of occupational exposure to radon and its decay products. Absorbed dose rates were performed using TL dosimeters, type TLD-200 (CaF_2-Dy) in a continuous monitoring program (integrated measurements). Dose rate levels as high as 110 nGy x h"-"1 were recorded inside the cave. In interpreting the high levels of radiation doses, radioactivity measurements regarding the naturally occurring "2"3"8U, "2"3"2Th and "4"0K radionuclides were carried out in various speleothems found at different sites in the cave. (author)

Energy Technology Data Exchange (ETDEWEB)

Simulations and experiments have been carried out to explore using a plastic scintillator as a dosimetry probe in the vicinity of a pulsed bremsstrahlung source in the range 4 to 20 MeV. Taking advantage of the tissue-equivalent properties of this detector in conjunction with the use of a fast digital signal processor near real-time dosimetry was shown to be possible. The importance of accounting for a broad energy electron beam in bremsstrahlung production, and photon scattering and build-up, in correctly interpreting dosimetry results at long stand-off distances is highlighted by comparing real world experiments with ideal geometry simulations. Close agreement was found between absorbed energy calculations based upon spectroscopic techniques and calculations based upon signal integration, showing a ratio between 10 MeV absorbed dose to 12 MeV absorbed dose of 0.66 at a distance of ...

International Nuclear Information System (INIS)

The Monte Carlo transport codes LAHET and MCNP were used to calculate energy fluence spectra at three neutron therapy facilities. The results compare very favourably with measured data. Kerma spectra and the ratio of ICRU muscle tissue kerma to A-150 kerma, along the carbon to oxygen kerma ratio, were determined. Absorbed dose rate calculations are in reasonable agreement with measured values. Use of these codes to study modifications to existing therapy beams is briefly discussed. (author).

International Nuclear Information System (INIS)

With accurate calculation algorithms in inverse planning for beamlet-based intensity modulated radiotherapy (IMRT), it takes time to calculate the dose matrix, which represents the dose distribution of each beamlet element to each voxel for unit fluence. To reduce the calculation time, coarse or approximate algorithms are often a choice, but this results in a final dose distribution that cannot reflect the real value. In addition, it is necessary to test if a coarse algorithm is capable of calculating the dose matrix of beamlets. In this work, simulated dynamics optimization algorithm was applied to optimize the segment weight to minish the dose error from the dose matrix calculation. After calculating the dose matrix by ray-tracing algorithm which takes into account just the primary component of absorbed ...

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Several short-lived, high-energy beta emitters are being proposed as the radionuclide components for molecular-targeted potential cancer therapeutic agents. The laboratory mice used to determine the efficacy of these new agents have organs that are relatively small compared to the ranges of these high-energy particles. The dosimetry model developed by Hui et al. was extended to provide realistic beta-dose estimates for organs in mice that received therapeutic radiopharmaceuticals containing 90Y, 188Re, 166Ho, 149Pm, 64Cu, and 177 Lu. Major organs in this model included the liver, spleen, kidneys, lungs, heart, stomach, small and large bowel, thyroid, pancreas, bone, marrow, carcass, and a 0.025-g tumor. The study as reported in this paper verifies their results for 90Y and extends them by using their organ geometry factors combined with newly calculated organ self-absorbed fractions from PEREGRINE and MCNP. PEREGRINE and MCNP agree to within 8% ...

International Nuclear Information System (INIS)

Following the publication (Stenhouse and Baxter, Nature; 267:828 (1977)) of the levels of bomb "1"4C and the residence times of carbon in the human body, excess radiation burdens from this radioisotope are evaluated under the assumption that no radiation dose, however small, can be regarded as entirely harmless biologically. The estimated annual absorbed dose attributable to "1"4C both natural and man-made for 1953-1973 and similar predicted figures for 1975-2025 are shown graphically. The cumulated doses to gonads (over 30 yr) and to bone marrow and bone-lining cells (over 60 yr) and also estimates of the biological damage to reproductive cells from "1"4C #beta#-irradiation (30 yr accumulated dose) are presented. It is concluded from both genetic and somatic considerations, that the potential human radiation burden due to artificially produced "1"4C calculated using the assumptions ...

Energy Technology Data Exchange (ETDEWEB)

Graft copolymerization of sodium styrene sulfonate (SSS) onto electron beam (EB) irradiated poly(vinylidene fluoride) (PVDF) films was investigated to find out a simple preparation process for sulfonic acid proton exchange membranes with respect to monomer concentration, absorbed dose, temperature, film thickness and storage time. The reaction order of the monomer concentration and absorbed dose of grafting was found to be 2.84 and 1.20, respectively. The overall activation energy for graft copolymerization reaction was calculated to be 11.36 kJ/mol. The initial rate of grafting was found to decrease with an increase in the film thickness. The trapped radicals in the irradiated PVDF films remained effective in initiating the reaction without considerable loss in grafting level up to 180 days, when stored under -60 {sup o}C. The presence and distribution of polystyrene sulfonate grafts in the obtained ...

International Nuclear Information System (INIS)

The X-band EPR spectra of unirradiated and "6"0 Co gamma ray irradiated cardamom (Elettaria cardamomum L. Maton, Zingiberaceae), ginger ((Zingiber officinale Rosc., Zingiberaceae), saffron (Crocus sativus L., Iridaceae), and curry have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones, most probably due to the presence of semiquinones, previously reported to have paramagnetic properties. After gamma ray irradiation at absorbed dose up to 11.3 kGy we have noticed in all spices the presence of complex EPR spectra consisting of a superposition of at last two different paramagnetic species whose amplitude increase monotonously with the absorbed dose. A 100 deg. C isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that form the initial spectra, but even ...

Energy Technology Data Exchange (ETDEWEB)

Gel dosimetry is a new dosimetry method applied in radiation therapy. Gel dosimeters consist of a radiation sensitive gel, which can integrate absorbed doses from several radiation sources or beams. The dose to the gel can be evaluated by magnetic resonance imaging (MRI), a procedure that is the focus of the present thesis. A robust tool for the evaluation of the nonuniformity in MRI has been developed, the Deviation Image method. Unlike previously presented methods, the Deviation Image method includes all nonuniformity variations across a phantom surface and is insensitive to stochastic noise. Methods for the estimation of stochastic noise were analyzed in terms of sensitivity to nonuniformities. A method that averages the stochastic noise level over five regions over the phantom surface, and a method that assesses the stochastic noise level from the background, were found to be the methods of choice. Pronounced MR image ...

International Nuclear Information System (INIS)

The somatic and genetic radiation exposure of patients undergoing Digital Subtraction Angiography (DSA) and traditional Film Arteriography (FA) of cranial, cervical, thoracic and abdominal vascular territories are compared. The radiation doses absorbed within the critical organs - red bone marrow, lung, thyroid gland and female breast - and in the gonads were measured using an anthropomorphic Alderson phantom. A Somatic Dose Index was calculated in order to estimate the somatic radiation risk. The somatic radiation exposure depends upon the location of the critical organs with respect to the entrance site of the x-ray beam, and can be reduced by an appropriate choice of the angiographic projection. Under this condition, the radiation exposure of the patient during DSA can be lower than during FA. For renal DSA an a.p. projection, the use of an abdominal compression device and careful caudal shielding of the field are ...

British Library Electronic Table of Contents (United Kingdom)

Purpose To study the chemical modifications induced upon irradiation of solid human insulin at radiosterilization doses and investigate the influence of the absorbed dose on radiolysis. Materials and Methods Volatile radiolytic products were monitored by gas chromatography coupled with mass spectrometry (GC-MS) and non-volatile products by two different high performance liquid chromatography (HPLC) methods: the formation of higher molecular weight proteins was assessed by size exclusion liquid chromatography whereas assays for related compounds and chemical potency tests were carried out using reverse-phase HPLC-UV. Conformational changes were investigated by measurements of circular dichroism. Results After gamma irradiation at 10?kGy, the recovery of insulin was 96.8%; higher molecular w...

International Nuclear Information System (INIS)

In October last year the first intercomparison of measurements of the soil radon concentrations between various laboratories in Slovakia was realised. The organisation of this intercomparison was conducted by the Slovak Legal Metrology in Banska Bystrica together with the Slovak National Accreditation Service in Bratislava (SNAS). The scientific guarantee of the exercise was the State metrological Centre for radon quantities, which is working at the Research base of Slovak Medical University in Bratislava. The main objective of the intercomparison was to verify the correctness of the methods for the soil radon measurements of the authorised laboratories for radon volume activities in soil air. The intercomparison (signed as SLM ILC 3/03) was performed as a 'circular' metrology comparison, in accordance with a methodical directive MSA 0117-98, published by SNAS. Six laboratories were participating on the intercomparison and ...

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This study evaluates the effect of gamma radiation on the viability of fungi and actinomycetes that contaminate medicinal plants. The relationship between the total lipids of some fungi and actinomycetes and their sensitivity to gamma radiation is also investigated. The data reveal that the viable counts of these florae decrease approximately exponentially with the radiation dose, the effective dose for the elimination of these microorganisms being about 5 kGy for all the medicinal plants under study. Response of pure cultures of fungi and actinomycetes isolated from medicinal plants to increasing absorbed doses of gamma radiation indicate that an increase in radioresistance is in the following order: Streptomyces rimosus, Fusarium solani, Nocardia kuroishii. F. oxysporum, A. fumigatus, A. flavus, A. parasiticus and A. ochraceus. The total lipid contents of molds and actinomycetes have been reported to ...

International Nuclear Information System (INIS)

Dairy products doubly labeled with 45Ca and 47Ca were used to evaluate an extrinsic labeling procedure for calcium bioavailability determination. Nonfat milk, yogurt, and fresh cheese curd were prepared from caprine milk that was intrinsically labeled with 45Ca. The products were then labeled extrinsically with 47Ca and administered to rats by gavage. The 47Ca to 45Ca ratio in bone and teeth averaged about 1.00 with either milk, yogurt, or CaCl2, but the ratio was about 1.04 when dosed with cheese curd. Ca absorption, determined by whole-body counting of 47Ca, was lower (P less than 0.05) in cheese curd (59%) than in either milk (69%), yogurt (72%), or CaCl2 (72%). Expressed as percent of dose, the absorption of 47Ca was highly correlated with bone 47Ca (r = 0.973) and with bone 45Ca (r = 0.946). Correlation between tibia 47Ca and tibia 45Ca was r = 0.923. For the dairy products tested, our results indicated that extrinsic 47Ca was ...

KoreaScience (Korea)

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International Nuclear Information System (INIS)

the cotton leaf worm, Spodoptera littoralis (boisd.) were irradiated with 100,150 and 200 Gy to induce inherited sterility. the effects of the tested doses applied to these pupae through three consequent fillial generations and the retarded influence on their F_1,F_2 and F_3 generations progeny were examined . irradiation of parental male induced damage to their daughter females ovaries. the overioles of females among P_1 ,F_1 and F_2 generations showed that the follicular epithelial cells appeared abnormal beside their limited separation from developing oocytes which became shrinked, semi absorbed or completely absorbed leaving vacuoles. the nurse cells were reduced or absent in some parts. damage was obvious through the first and second generations especially at 150 and 200 Gy. in the third generation, ovaries were not greatly affected

International Nuclear Information System (INIS)

Full text: Optically stimulated luminescence (OSL) dating of individual sand-sized grains of quartz has advanced significantly over the past decade opening up new vistas in luminescence geochronology. Today, single-grain OSL dating can be used to constrain the burial ages of many deposits, including fluvial sediments, glaciofluvial material and archaeological sediments. It also provides a means of examining the stratigraphic integrity of archaeological sites where sediment mixing might have occurred. An OSL age is calculated by dividing the burial dose (the dose absorbed by the grain since it was last exposed to sunlight) by the environmental dose rate (the rate of supply of ionizing radiation to the grain over the period of burial). To obtain reliable OSL ages, therefore, an accurate estimate of the dose rate is required for each sample. Here we describe our OSL dating campaign at ...

Energy Technology Data Exchange (ETDEWEB)

New values of the factors required to convert the reading of a radiation dosemeter calibrated in terms of air kerma (or exposure) into absorbed dose to water for medium-energy x-radiation were given in a code of practice published by the International Atomic Energy Agency in 1987. These are not considered to possess sufficient support from other sources. It is therefore recommended that the F-factors given or codes of practice should continue to be used. Values of backscatter factors for low-energy x-radiation (below 140 kV) in Supplement 17 of the British Journal of Radiology appear to be inaccurate. New values based on Monte Carlo calculations, and supported by new experimental data, are given for use in radiotherapy. (author).

Energy Technology Data Exchange (ETDEWEB)

It was developed a new formulation of macro aggregates of Samarium 153 ({sup 153} Sm-MH) for the arthropaties treatment. The radio pharmaceutic was prepared by reaction of Samarium 153 chloride (SmCl{sub 3}) in aqueous environment with sodium boron hydride in NaOH 0.5 N. The microscopic analysis shown that the particles have an average size of 4% m (range 1-14 {mu} m). The velocity of sedimentation was 0.008 cm/min with high stability in vitro in human serum. The biological studies in healthy rabbits, shown that the complex is retained inside the articulation still eight days after of the administration of the radiopharmaceutical. Likewise, it is presented the data of absorbed dose in the different target organs, which was determined by thermoluminescent dosimetry (TLD) through the use of a REMCAL phantom (radiation equivalent manikin calibration). (Author)

Energy Technology Data Exchange (ETDEWEB)

With the exception of the 1945 Hiroshima and Nagasaki nuclear weapon explosions and the 1986 Tchernobyl reactor accident, most of the radiation accidents concerns the medical and the traditional industrial sectors. The seriousness of the accident is directly function of the absorbed dose. The paper, first, gives the definition of a radiologic accident with its specific criteria and pathological manifestations. Then, some famous historical accidents are reviewed from the discovery of X-rays to recent acute irradiations due to the careless manipulation of radiation sources. From this analysis, three main causes are put forward: the dysfunction of nuclear medicine apparatuses, the victims` lack of training and knowledge of the risks, and the non-identification or the loss of radiation sources. (J.S.). 1 photo.

International Nuclear Information System (INIS)

A tissue-equivalent dosimetry system has been developed for use in absorbed dose determinations with physical models of Reference Man. The dosimeter used was a thermo-luminescent dosimeter (TLD) powder which was mixed with a 'tissue-equivalent' material and modeled to closely approximate an organ's geometry and absorption properties. A separation procedure was developed by which the TLD powder was washed and the 'tissue-equivalent' material, a wax, was dissolved and extracted following the irradiation of the model. The procedure was tested to determine losses of powder, homogeneity of the powder's distribution throughout the wax, the effects of the separation procedure upon the powder and the statistical behavior of the procedure. The results of these tests established the feasibility of the procedure. A full-scale model of the pancreas was tested and the results supported the validity of the technique. (author)

Energy Technology Data Exchange (ETDEWEB)

In the case of total skin electron therapy without the beam guide, the electron beam is scattered just outside the gantry exit, dose uniformity in the field is broken, and dose is spread outside the light field. The aims of this study were to measure the mean energy of the off-axis incident electron beam without the beam guide and to establish a reference for the clinical situation. For the measurement, a 4 MeV electron beam was selected among several energies from the linear accelerator. A scintillating fiber beam energy monitor measured the mean energy of the incident electron beam. This energy monitor is a small, light-weight piece of equipment composed of a wedge absorber, scintillation fiber, and photodiode. We found the relationship between electron energy and the indicated value of the energy monitor by means of the estimation of correction factors for five different kinds of electron energy. The preferable linear ...

Energy Technology Data Exchange (ETDEWEB)

The effect of a complexon therapy scheme including early (in 1 h) administration of Na/sub 3/Ca DTPA and subsequent administration of Na/sub 3/Zn DTPA or Na/sub 3/Ca DTPA at a dose of 25 ..mu..Cimol/kg/day by three 2-week courses (5 times a week) with 2-week interruptions was studied in experiments on 541 male rats after intraperitoneal administration of /sup 239/Pu citrate complex (95 kBq/kg). The treatment resulted in a 3-fold lessening of the content of /sup 239/Pu and absorbed doses in the skeleton, a significant prolongation of the mean survival time (MST) from 452 to 593 days (Na/sub 3/Zn DTPA) and 643 days (Na/sub 3/Ca DTPA), and in a decrease of the osteosarcoma incidence from 76.4 to 32.6-41.2%. The ratio of osteosarcomas per 1 Gy retained in rats (0.076-0.083 %) did not differ from that in untreated animals.

Energy Technology Data Exchange (ETDEWEB)

Non-uniform radionuclide distribution in tumours will lead to a non-uniform absorbed dose. The aim of this study was to investigate how tumour control probability (TCP) depends on the radionuclide distribution in the tumour, both macroscopically and at the subcellular level. The absorbed dose in the cell nuclei of tumours was calculated for {sup 90}Y, {sup 177}Lu, {sup 103m}Rh and {sup 211}At. The radionuclides were uniformly distributed within the subcellular compartment and they were uniformly, normally or log-normally distributed among the cells in the tumour. When all cells contain the same amount of activity, the cumulated activities required for TCP = 0.99 (A-tilde{sub TCP=0.99}) were 1.5-2 and 2-3 times higher when the activity was distributed on the cell membrane compared to in the cell nucleus for {sup 103m}Rh and {sup 211}At, respectively. TCP for {sup 90}Y was not affected by different ...

International Nuclear Information System (INIS)

Brachytherapy is used for treating certain types of cancer by inserting radioactive sources into tumours. CDTN/CNEN is developing brachytherapy seeds to be used mainly in prostate cancer treatment. Dose calculations play a very significant role in the characterization of the developed seeds. The current state-of-the-art of computation dosimetry relies on Monte Carlo methods using, for instance, MCNP codes. However, deterministic calculations have some advantages, as, for example, short computer time to find solutions. This paper presents a software developed to calculate doses in a two-dimensional space surrounding the seed, using a deterministic algorithm. The analysed seeds consist of capsules similar to IMC6711 (OncoSeed), that are commercially available. The exposure rates and absorbed doses are computed using the Sievert integral and the Meisberger third order polynomial, respectively. The software ...

International Nuclear Information System (INIS)

Measurement results are interpreted as (sets of) values attributed to measurands, i.e., quantities (intended to be measured), i.e., properties (having a magnitude that can be expressed as a number and a reference). This relatively simple conceptual structure hides some important issues for measurement science, that the lecture will tentatively explore with a systematic reference to the International vocabulary of metrology - Basic and general concepts and associated terms (VIM) and its possible future developments.

International Nuclear Information System (INIS)

For the determination of the elemental composition of insoluble endogenous fractions from gastrointestinal tract by SRXRF (XRF experimental beam line, VEPP-3, INP SU RAS, Novosibirsk), an analytical method was developed for producing epithelial tissue in vivo. The metrological characteristics were determined using a number of international biological standards.

International Nuclear Information System (INIS)

Full text: A semiempirical algorithm for absorbed dose calculation at off-axis points in irregular beams was implemented. It is well known that semiempirical methods are very useful because of their easy implementation and its helpfulness in dose calculation in the clinic. These methods can be used as independent tools for dosimetric calculation in many applications of quality assurance. However, the applicability of such methods has some limitations, even in homogeneous media, specially at off axis points, near beam fringes or outside the beam. Only methods derived from tissue-air-ratio (TAR) or scatter-maximum-ratio (SMR) have been devised for those situations, many years ago. Despite there have been improvements for these manual methods, like the Sc-Sp ones, no attempt has been made to extend their usage at off axis points. In this work, a semiempirical formalism was introduced, based on the works of Venselaar et al. ...

Energy Technology Data Exchange (ETDEWEB)

Molybdenum is an essential element for living organisms. Moreover its radionuclides may represent an incorporation risk for members of the public and/or radiation workers after a nuclear accident or a release of radioactive materials. However, only few reliable data on Mo biokinetics in humans were available. The results of recent tracer kinetic investigations with stable isotopes have shown several differences from the ICRP data with regard to the processes of intestinal absorption and of excretion. As a consequence, the dose coefficients calculated with a revised biokinetic model deviate from the ICRP estimates. By ingestion of {sup 99}Mo radionuclides with solid food, for example, the dose to the colon may be higher of a factor up to 1 order of magnitude, due to the fraction of non-absorbed material which traverses the gastro-intestinal tract. (orig.) [Deutsch] Molybdaen ist einerseits ein fuer Lebewesen essentielles ...

Energy Technology Data Exchange (ETDEWEB)

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and has very limited therapeutic options. Recently, it has been found that hyaluronic acid (HA) shows selective binding to CD44 receptors expressed in most cancer histotypes. Since the trend in cancer treatment is the use of targeted radionuclide therapy, the aim of this research was to label HA with rhenium-188 and to evaluate its potential use as a hepatocarcinoma therapeutic radiopharmaceutical. Methods: {sup 188}Re-HA was prepared by a direct labelling method to produce a ReO(O-COO){sub 2}-type coordination complex. {sup 188}Re-HA protein binding and its stability in saline, phosphate buffer, human serum and cysteine solutions were determined. Biokinetic and dosimetric data were estimated in healthy mice (n=60) using the Medical Internal Radiation Dose methodology and mouse model beta-absorbed fractions. To evaluate liver toxicity, alanine aminotranferase (AST) and ...

KoreaScience (Korea)

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KoreaScience (Korea)

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International Nuclear Information System (INIS)

The Seismic Proving Test of Heavy Component with Energy Absorbing Supports has been conducted to prove the reliability of advanced seismic technology, supporting heavy component such as PWR steam generator with large capacity energy absorbing supports under the sponsorship of Ministry of Economical Trade and Industry. If energy absorbing supports are adopted for NPP heavy components, support structure of facility will be much simplified due to their seismic energy absorbing effect. The paper describes the results of lead damper element test and seismic test at Tadotsu Laboratory, using 1/2.5 scale PWR Steam Generator model supported by Lead Extraction Damper (LED) and development of characteristics evaluation formula of energy absorbing support. (author)

Energy Technology Data Exchange (ETDEWEB)

Natural radioactive materials under certain conditions can reach hazardous radiological levels. The natural radionuclide ({sup 238}U, {sup 232}Th, {sup 40}K) contents of rock samples at various locations in the North Tushki area were investigated using gamma-spectrometric analysis. Estimates of the measured radionuclide content have been made for the absorbed dose rate of gamma radiation. The equivalent radium (R{sub eq}) and the external hazard index (H{sub ex}) which resulted from the natural radionuclides in soil are also calculated and tabulated. The studied samples have been collected from various rock exposures in the North Tushki area. The distribution of major oxides, U and Th were studied. It is found that the enrichment and depletion of the major oxides are mainly due to the effect of hydrothermal alteration, which caused mobility of some major oxides, which increases some elements and decreases others. It is important to mention that ...

International Nuclear Information System (INIS)

Alanine/EPR Dosimetry system is classified as a reference-standard dosimeter which used to calibrate radiation environments and to calibrate routine dosimeters in absorbed dose range of 1 to 105 Gy. Characteristics of Alanine/EPR dosimetry system are better suitable than routinely used personnel dosimeters for the long term radiation measurement in harsh condition of Nuclear power plant : This system is not significantly affected by temperature and humidity and also has low fading rate. About 1 year ago, Alanine and Lithium compound dosimeters were installed at Wolsung unit 1 for the environment monitoring as a part of equipment qualification program. 35 positions which are most severe and representative cable positions were chosen for radiation and temperature monitoring. The recovered alanine dosimeter in the period of maintenance was measured by E-scan alanine analyzer system, Meanwhile measurement result shows extremely high radiation level ...

International Nuclear Information System (INIS)

The admissibility of nuclear forensics measurements and opinions derived from them in US Federal and State courts are based on criteria established by the US Supreme Court in the case of Daubert v. Merrell Dow and the 2000 Amendment of Rule 702 of the Federal Rules of Evidence. These criteria are being addressed by new efforts that include the development of certified reference materials (CRMs) to provide the basis for analytical method development, optimization, calibration, validation, quality control, testing, readiness, and declaration of measurement uncertainties. Quality data is crucial for all stages of the program, from R and D, and database development, to actual casework. Weakness at any point in the program can propagate to reduce the confidence of final conclusions. The new certified reference materials will provide the necessary means to demonstrate a high level of metrological rigor for nuclear forensics evidence and will form a foundation for legally ...

International Nuclear Information System (INIS)

Surface quality is one of the most important criteria for establishing the optimum cutting parameters needed to perform a machining process. Usually, the evaluation of the degree of the surface finishing requires to apply metrological techniques which involve times out in the production. As a consequence of this, a loss in both the economy of the process and the fiability of the tests reproducibility can be produced. In this work a relation between cutting force and surface roughness has been studied for the turning process of an Al-Cu alloy. From this relation, the surface quality of the machined samples can be evaluated by using the cutting forces values acquired during the cutting process. (Author) 8 refs.

International Nuclear Information System (INIS)

A number of ion exchange materials are being evaluated as part of the Tank Waste Remediation System (TWRS) Pacific Northwest Laboratory (PNL) Pretreatment Project for the removal of "1"3"7Cs from aqueous tank wastes. Two of these materials are organic resins; a phenol-formaldehyde resin (Duolite CS-100) produced by Rohm and Haas Co. (Philadelphia, Pennsylvania) and a resorcinol-formaldehyde (RF) resin produced by Boulder Scientific Co. (Mead, Colorado). One of the key parameters in the assessment of the organic based ion exchange materials is its useful lifetime in the radioactive and chemical environment that will be encountered during waste processing. The focus of the work presented in this report is the radiation stability of the CS-100 and the RF resins. The scope of the testing included one test with a sample of the CS-100 resin and testing of two batches of the RF resin (BSC-187 and BSC-210). Samples of the exchangers were irradiated with a "6"0Co source to a total ...

International Nuclear Information System (INIS)

The patients studied were referred for routine abscess localization with indium-111 labelled autologous leukocytes. One series (n=15) was studied at 1 day after reinjection of labelled cells and a second series (n=9) was studied between 4 hours and 4 days after reinjection of labelled cells. The leukocytes were isolated by a gravity sedimentation method and labelled with In-111 oxinate according to Roevekamp and co-workers. The labelled cell suspension administered to the patient contained between 11 and 15 MegaBq (300-400 microCi). The indium-111 concentration in the liver and spleen was quantitated using a scintillation camera and an on-line computer system. Phantom studies were carried out to obtain conversion factors from geometric mean counts to MegaBq of activity for both liver and spleen. Once determined, the amount of activity in liver and spleen was corrected for physical decay of In-111 and expressed as a percentage of the administered activity. Additionally in the 2nd series ...

Energy Technology Data Exchange (ETDEWEB)

The optically stimulated luminescence (OSL) results a highly appropriate dosimetric technique for readings of absorbed radiation 'in alive' and 'in situ', as well as in real time. The CVD diamond on the other hand presents excellent qualities like radiation reader thanks to its reproducibility, radiation resistance, biocompatibility and non toxicity. The present work studies the answer of two diamond films pure and polluted with nitrogen (750 ppm) grown by the Chemical Vapor Deposition method (CVD) on silicon substrate (001) irradiated with beta (Sr-90) in the 0.833-100 Gy interval. The optical stimulation was carried out by 40 seconds with infrared laser (830 nm, 0.36 W/cm{sup 2}) and the filter BG-39 (300-600 nm) coupled the PM. The intensity and the decay of the hyperbolic type of the LOE curves were similar in both samples, for the non doped diamond were observed trapping states in 200-380 C being compared with those that it ...

Energy Technology Data Exchange (ETDEWEB)

The present study was designed to investigate, in more detail, the mechanism of lead transport by the gastrointestinal tract and particularly the similarities or dissimilarities between lead and calcium in this process. The absorption of these metals was determined in 3-week-old white Leghorn cockerels, raised on a commercial diet or special diets, using an in vivo ligated loop procedure. The dose administered into the loop usually contained 0.5 ..mu..Ci /sup 203/Pb (and/or 0.1 ..mu..Ci /sup 47/Ca), 0.01 mM lead acetate (and/or 1 mM CaCl/sub 2/) in 0.5 ml of 0.15 M NaCl, pH 6.5. It was shown that lead is rapidly taken up by the intestinal tissue, and only slowly transferred into the circulation whereas calcium, also accumulated rapidly by the tissue, is rapidly released from the tissue in the serosal direction. The absorption processes of these cations show similar responses to various experimental conditions (low calcium intake, age of the animal, pH of the ...

Energy Technology Data Exchange (ETDEWEB)

The radionuclide characteristics of light-water-reactor (LWR) spent fuel play key roles in the design and licensing activities for radioactive waste transportation systems, interim storage facilities, and the final repository site. Several areas of analysis require detailed information concerning the time-dependent behavior of radioactive nuclides including (1) neutron/gamma-ray sources for shielding studies, (2) fissile/absorber concentrations for criticality safety determinations, (3) residual decay heat predictions for thermal considerations, and (4) curie and/or radiological toxicity levels for materials assumed to be released into the ground/environment after long periods of time. The crucial nature of the radionuclide predictions over both short and long periods of time has resulted in an increased emphasis on thorough validation for radionuclide generation/depletion codes. Current radionuclide generation/depletion codes have the capability to follow the ...

International Nuclear Information System (INIS)

Random motion of a particle, emitting and absorbing tachyons, is investigated. It is shown that if bradyon is in equilibrium with neutral gas, i.e. it absorbs and emits tachyons, which do not have any charges, tha particle with each absorption-emittance of a tachyon changes its energy and momentum, never varying its own mass, and as a result it moves like a brownian particle. Thus, bradyon, interacting with tachyon gas, increases its momentum continuously in agreement with the Einstein-Fokker-Planck type equation.

Energy Technology Data Exchange (ETDEWEB)

The effects of fine-particle C, such as diesel soot, on the optical properties of urban haze in the visible wavelength range were explored to determine the dominant effects and to see if simple parameters (such as visual range in green) provide an adequate measure of these effects. It is known that fine-particle C absorbs more strongly in the blue than in the red, so that when it is mixed with a white pigment, the resulting gray can appear somewhat brown. The possibility of a similar effect in urban hazes was investigated, but found not to occur. When the sun is overhead, the near-horizon sky chromaticities caused by mixtures of fine-particle C and non-absorbing aerosol can also be produced by non-absorbing aerosols alone. It is shown that absorbing aerosol will darken the horizon sky, and a simple equation for the radiance of the horizon sky is derived. The effect of absorbing ...

International Nuclear Information System (INIS)

... dose rates inhalation iodine 134 krypton 88 nuclear decay quality factor

International Nuclear Information System (INIS)

The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm"-"3 or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant applications. Many of the design features and the end application itself set these TGS systems ...

International Nuclear Information System (INIS)

To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that 1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; 2) approximately equal detection rates were obtained for the three X-ray filter sets, although results with the tungsten filter were ...

International Nuclear Information System (INIS)

The differing susceptibility of individuals to the toxic effects of chronic lead exposure has never been fully understood. As the major intake of lead in the human is from food and beverages, any variation between individuals of the quantity of lead absorbed from the gut, and of the distribution and excretion of this lead, may account for the differences in individual susceptibility. The food and beverages themselves may have an influence, and to investigate their effects on absorption, distribution and excretion of lead, experiments were performed on normal subjects using a short lived radionuclide of lead, "2"0"3Pb, and instruments generally available in Nuclear Medicine. Lead absorption between different individuals showed a wide variation when "2"0"3Pb was taken as a single dose between meals. Minerals were found to be mainly responsible for affecting absorption when one subject ingested "2"0"3Pb in control meals from which one dietary ...

International Nuclear Information System (INIS)

Natural radioactive materials under certain conditions can reach hazardous radiological levels. The natural radionuclide ("2"3"8U, "2"3"2Th, "4"0K) contents of rock samples at various locations in the North Tushki area were investigated using gamma-spectrometric analysis. Estimates of the measured radionuclide content have been made for the absorbed dose rate of gamma radiation. The equivalent radium (R_e_q) and the external hazard index (H_e_x) which resulted from the natural radionuclides in soil are also calculated and tabulated. The studied samples have been collected from various rock exposures in the North Tushki area. The distribution of major oxides, U and Th were studied. It is found that the enrichment and depletion of the major oxides are mainly due to the effect of hydrothermal alteration, which caused mobility of some major oxides, which increases some elements and decreases others. It is important to mention that the study area is ...

Energy Technology Data Exchange (ETDEWEB)

The transfer of 203Pb and/or 47Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). 203Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of 203Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of 203Pb by intestinal tissue but did accelerate 203Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased 47Ca tissue levels and increased 47Ca absorption. In rachitic chicks, the rate of absorption of 203Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in al segments was similar, indicting the order of cholecalciferol effectiveness as duodenum greater than or equal to jejunum greater than ileum. An acute dose of 1,25(OH)2D3 ...

Energy Technology Data Exchange (ETDEWEB)

The absorbed dose delivered to the patient in brachytherapy is directly proportional to the source strength in terms of the reference air-kerma rate (RAKR). Verification of this quantity by the hospitals is widely recognized as an important part of a quality assurance program. An external audit was performed on behalf of the Secondary Standard Dosimetry Laboratory at the Swedish Radiation Protection Authority (SSI). The aim was to investigate how accurately the source-strength in 192Ir brachytherapy is determined at Swedish hospitals. The SSI reference well-type ion chamber and calibrated equipment were used to measure the RAKR of an 192Ir source in each of the 14 Swedish afterloading units. Comparisons with values determined by vendors and hospitals were made. Agreement in values of RAKR as determined by SSI, hospitals and vendors were in all cases within the +-3% uncertainty (at a coverage factor of k=2), typically guaranteed by the vendors. ...

British Library Electronic Table of Contents (United Kingdom)

The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, wh...

British Library Electronic Table of Contents (United Kingdom)

The Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, developed an alignment strategy to specify elemental depth profiling in vertical sidewall layers on structured wafers. For this purpose, PTB's irradiation chamber for 200?mm and 300?mm silicon wafers was used to combine total-reflection X-ray fluorescence (TXRF) and grazing incidence XRF (GIXRF) techniques by employing monochromatized undulator radiation of the BESSY II electron storage ring. 3-D test structures were fabricated to develop an optimal alignment strategy allowing for depth profiling in such nanolayers. The test structures consisted of silicon bars with widths/spacings either in the ?m or in the nm range. In order to be able to differentiate the sidewalls more easily from the remainder of ...

CERN Document Server

Modeling artificial scanning electron microscope (SEM) and scanning ion microscope images has recently become important. This is because of the need to provide repeatable images with a priori determined parameters. Modeled artificial images are highly useful in the evaluation of new imaging and metrological techniques, like image-sharpness calculation, or drift-corrected image composition (DCIC). Originally, the NIST-developed artificial image generator was designed only to produce the SEM images of gold-on-carbon resolution sample for image-sharpness evaluation. Since then, the new improved version of the software was written in C++ programming language and is in the Public Domain. The current version of the software can generate arbitrary samples, any drift function, and many other features. This work describes scanning in charged-particle microscopes, which is applied both in the artificial image generator and the DCIC technique. As an example, the performance ...

Energy Technology Data Exchange (ETDEWEB)

A shock absorber mechanism and method for use on the leg structure of a jack-up offshore drilling rig is described. It is mounted on the bottom of each existing leg of a drilling rig and comprises a pointed piston member which is positioned on the bottom of the leg structure and projects downwards through the can/footing of the rig leg. The piston member is held in place by a resilient tension member which is designed to absorb shock forces during vertical/axial impact of the leg structure when contact is made with the ocean floor. (author).

International Nuclear Information System (INIS)

Full text: Thermoluminescence (TL) is a phenomenon of light emission caused by heating a pre-irradiated material. When ionizing radiation hits a TL material, electrons are freed from some atoms and moved in the material, leaving behind 'holes' of positive charge. Subsequently when the TL material is heated, the electrons and the 'holes' re-combine, and release the extra energy in the form of light. The light intensity can be measured, and related to the amount of energy initially absorbed through exposure to the ionizing radiation. In nineteen sixties thermoluminescence dosimeters (TLD) became popular for dosimetric applications in view of their small size, sensitivity and accuracy. Consequently, in early seventies, several countries started adopting of TLD for personnel monitoring. The idea of introducing TLD to replace the then prevalent film dosimeter for personnel monitoring in India was mooted and successfully implemented by Dr. K G Vohra. Limitations of ...

Science.gov (United States)

This paper presents the development and evaluation of field- controllable, semi-active magneto-rheological fluid (MRF) shock absorbers for a mountain bicycle. Recent trends in the bicycle industry show a movement towards semi-active suspension systems. Two new MRF dampers are designed and tested with the intent of being used on the front and rear suspension of a modern mountain bicycle. The MRF shock absorbers are designed to emulate the performance of the original equipment manufacturer shock absorbers in passive mode. Application of an input electric current to the MRF shock absorber causes a dramatic increase in the damping capacity. Procedures and results are presented for the design and experimental characterization of these MRF dampers.

Science.gov (United States)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this ...

Energy Technology Data Exchange (ETDEWEB)

An emergency shutdown system for high-temperature gas-cooled pebble-bed reactors is proposed in addition to the common absorber rod shutdown system. This system is based on the strongly absorbing effect of small boronated graphite spheres (called KLAK), which trickle in case of emergency by gravity from the top reflector into the reactor core. The inner reflector of the Siemens-Argonaut reactor was substituted by an assembly of spherical Arbeitsgemeinschaft Versuchsreaktor fuel elements, and the shutdown effect was examined by installing well-defined KLAK nests inside this assembly. The purpose was to develop and prove a calculational procedure for determining criticality values for assemblies of large fuel spheres and small absorbing spheres.

Energy Technology Data Exchange (ETDEWEB)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positiond in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts radiation from the front of the absorber. With this arrangement, a ...

International Nuclear Information System (INIS)

In the WWER-440 reactor the primary piping consists of six horizontal loops going radially from the pressure vessel, each loop having a horizontal steam generator. In this reactor type the relatively long primary piping with many curved sections requires special attention in order to successfully eliminate the consequences of the design basis accident. Emergency supports are located in appropriate places to restrict the movements of the pipe. Under normal conditions there is a gap of some centimeters between the pipe and a support so that in the pipe can be deformed freely under changing loads. This paper deals with those energy-absorbing structures used at the Loviisa Nuclear Power Plant for protection against impact loading. Places and circumstances where energy-absorbing structures are employed are specified. Development and design of impact absorber elements are discussed and impact tests are described. (Auth.).

International Nuclear Information System (INIS)

The behaviour of the packaging materials under radiation field has a great importance in radiation processing, because, in most cases, they are finally responsible for the preservation of the beneficent changes achieved in irradiated products. For example, in radiation sterilisation and food irradiation, the packages must preserve the sterilisation, respectively the sanitisation. They must preserve also the physical barrier feature. The radiation effects on plastics were extensively studied in the last decades for nuclear industry and more recently for radiation processing. The two major effects of nuclear radiation on polymeric materials are the degradation and cross-linking. The degradation consists in breaking of macromolecules after interaction with nuclear particles, amplified by the free radicals which persist long periods, especially in crystalline polymers. Oxygen could penetrate the sample and interact with free radicals so that the degradation process continues after the ...

International Nuclear Information System (INIS)

The single-axis portion of a three-axis superconducting gravity gradiometer has been completed in the course of this research. The theory of the superconducting gravity gradiometer has been generalized and put into a Lagrangian formulation. A condition for frequency-independent common mode balance combined with a multi-stage vibration isolation scheme has enabled a stable operation of the gradiometer for prolonged periods. In a preliminary test, the gradiometer has exhibited a noise level of 1-2 E Hz"-/sup 1/2/ below 1 Hz, limited by seismic noise, where 1 E = 10"-"9 m s"-"2 m"-"1. To perform a test of the inverse square law, the single-axis gradiometer is mounted with its axis tilted from the vertial by an angle tan"-"1 #sq root#2. The device is then turned incrementally by 120"0 around the vertical to carry the gradiometer from one axis to the other two axes of an orthogonal coordinate system. A lead pendulum weighing 1600 kg forms a periodic monopole source of gravity. The ...

Science.gov (United States)

Examples are used to demonstrate that a shift in the point of emphasis is necessary with regard to radiation hazard in medicinal X-ray diagnosis. The parameters employed in this study to calculate somatic dose (SD) and somatically significant dose (SSD) m...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

A simple dose-saving procedure for the diagnosis of congenital hip dysplasia employing a diaphragm in nearfocus position is presented. Doses to the skin and the gonads were measured with a phantom for the new and other techniques. With optimal techniques the skin dose is smaller than 2 mR and the gonadal doses lie around 0.1 mR for both male and female patients. An estimate of the dose burden from undesired radiation is appended. (orig.).

Energy Technology Data Exchange (ETDEWEB)

One of the main disadvantages of solar air collectors in practical applications is their relatively low efficiency. In this experimental investigation, the shape and arrangement of absorber surfaces of the collectors were reorganized to provide better heat transfer surfaces suitable for the passive heat transfer augmentation techniques. The performance of such solar air collectors with staggered absorber sheets was tested. The experimental results show that it is possible to provide 10 to 25% enhancement in the efficiency compared to the conventional solar air collectors. (authors)

Energy Technology Data Exchange (ETDEWEB)

In studying the absorption of carbon dioxide by absorbents impregnated with alkanol amines, researchers used a laboratory-scale packed column to determine the overall gas-phase mass-transfer coefficients and enhancement factors. A model derived for the mechanism of the chemical reaction taking place in the interfacial layer accounts for the effect of the reaction upon the absorption rate better than other models.

Energy Technology Data Exchange (ETDEWEB)

LEDF(Large Equipment Dismantling Facility) is the solid waste processing technology development facility that carries out high-volume reduction and low dosage processing. The high-volume reduction processing of the high dose {alpha}-waste configured with combustible waste, pvc and rubber, spent ion exchange resin, and noncombustible waste have been planned the incinerating and melting facility using the in-can type high frequency induction heating in LEDF. This test is intended to clarify the design data. It was confirmed that the incinerating and melting performance, molten solid properties and exhaust gas processing performance with pilot testing equipment and bench scale equipment. The result of this test are as follows. 1. Processing speed is 6.7 kg/h for the combustible waste, 13.0 kg/h for the ion exchange resin, and 30.0 kg/h for the noncombustible waste. For above optimum processing conditions are as follows. Operating temperature is 1000degC for the ...

Energy Technology Data Exchange (ETDEWEB)

The Effective Dose Equivalent Concept defined by the International Commission on Radiological Protection in 1977 considers the risk from irradiation including both hereditary and somatic effects. This paper will deal with the definition of a concept for somatic effects only, the somatically significant dose equivalent. This is defined as the dose equivalent which if received by every member of the population, would be expected to produce the same total somatic injury to the population as does the actual dose equivalent received by various individuals. The somatically effective dose equivalent for a particular radiopharmaceutical is the weighted sum of the average dose equivalent to various organs. The dose equivalent to various organs can be derived from an extended MIRD formalism also considering the rest of body excluding the source ...

Energy Technology Data Exchange (ETDEWEB)

number of technical requirements and performance criteria can drive stellarator costs, e.g., tight tolerances, accurate coil positioning, low aspect ratio (compactness), choice of assembly strategy, metrology, and complexity of the stellarator coil geometry. With the completion of a seven-year design and construction effort of the National Compact Stellarator Experiment (NCSX) it is useful to interject the NCSX experience along with the collective experiences of the NCSX stellarator community to improving the stellarator configuration. Can improvements in maintenance be achieved by altering the stellarator magnet configuration with changes in the coil shape or with the combination of trim coils? Can a mechanical configuration be identified that incorporates a partial set of shaped fixed stellarator coils along with some removable coil set to enhance the overall machine maintenance? Are there other approaches that will simplify the concepts, improve access for ...

Science.gov (United States)

In the recent work [Proc. of SPIE 7801, 7801-2/1-12 (2010), Opt. Eng. 50(5) (2011), in press], we have reported on improvement of the Developmental Long Trace Profiler (DLTP), a slope measuring profiler available at the Advanced Light Source Optical Metrology Laboratory, achieved by replacing the bulk pentaprism with a mirror based pentaprism (MBPP). An original experimental procedure for optimal mutual alignment of the MBPP mirrors has been suggested and verified with numerical ray tracing simulations. It has been experimentally shown that the optimally aligned MBPP allows the elimination of systematic errors introduced by inhomogeneity of the optical material and fabrication imperfections of the bulk pentaprism. In the present article, we provide the analytical derivation and verification of easily executed optimal alignment algorithms for two different designs of mirror based pentaprisms. We also provide an analytical description for the mechanism for reduction ...

International Nuclear Information System (INIS)

Coal output in China increased from 872mt in 1985 to 1080mt in 1990, representing an annual growth rate of 4.37% . As the biggest coal burning country, it gives out a large amount of CO_2 and other pollutants into air, resulting in serious air pollution and sharing a great part in creating the global greenhouse effect. On the other hand, China faces severe energy shortage. Coal will remain the most important energy resource for a long time, Using the method of econometrics, this paper analyses the relations between China's energy production, consumption increase and national economic growth in the list forty years, makes comparisons with other countries, and points out problems of China's energy consumption increase and economic development. On this basis the strategy for developing China's energy industry is put forward, In the end, the authors advance that the leading position of energy industry in the national economy must be established and economic developing speed in China must ...

International Nuclear Information System (INIS)

We demonstrate detection of a single core-shell magnetite-silica nanoparticle (outer diameter #approx#120 nm, moment #approx#10"4#mu#_B) using an Nb dc superconducting quantum interference device (SQUID) with the loop size of 350 nm operational at T < 10 K. The system noise was minimized down to 0.2 #mu##PHI#_0 Hz"-"1"/"2 using a cryogenic SQUID series array pre-amplifier. Initial measurements of an individual magnetic nanoparticle were performed and a clear change of the noise spectra of the nano-SQUID was detected at low frequencies in the presence of the nanoparticle. Similar behaviour was confirmed with an FePt nanoparticle with a larger magnetic moment (diameter #approx#150 nm, moment #approx#10"6#mu#_B). Thus, we demonstrate a magnetic sensor based on a dc nano-SQUID and enabling detection of small moments (potentially down to a few electron spins). Such a sensor is of considerable significance for nanomagnetic metrology and quantum information processing ...

Energy Technology Data Exchange (ETDEWEB)

A modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays [Proc. SPIE 7077-7 (2007), Opt. Eng. 47, 073602 (2008)] has been proven to be an effective MTF calibration method for a number of interferometric microscopes and a scatterometer [Nucl. Instr. and Meth. A616, 172 (2010)]. Here we report on a further expansion of the application range of the method. We describe the MTF calibration of a 6 inch phase shifting Fizeau interferometer. Beyond providing a direct measurement of the interferometer's MTF, tests with a BPR array surface have revealed an asymmetry in the instrument's data processing algorithm that fundamentally limits its bandwidth. Moreover, the tests have illustrated the effects of the instrument's detrending and filtering procedures on power spectral density measurements. The details of the development of a BPR test sample suitable for calibration of scanning and transmission electron ...

Energy Technology Data Exchange (ETDEWEB)

We suggest and describe the use of a binary pseudo-random (BPR) grating as a standard test surface for measurement of the modulation transfer function (MTF) of interferometric microscopes. Knowledge of the MTF of a microscope is absolutely necessary to convert the measured height distribution of a surface undergoing metrology into an accurate power spectral density (PSD) distribution. For an'ideal' microscope with an MTF function independent of spatial frequency out to the Nyquist frequency of the detector array with zero response at higher spatial frequencies, a BPR grating would produce a flat 1D PSD spectrum, independent of spatial frequency. For a'real' instrument, the MTF is found as the square root of the ratio of the PSD spectrum measured with the BPR grating to the'ideal,' spatial frequency independent, PSD spectrum. We present the results from a measurement of the MTF of MicromapTM-570 interferometric ...

International Nuclear Information System (INIS)

A survey to determine the annual genetically significant dose and mean bone-marrow dose to the Australian population from radiological procedures has been undertaken. For diagnostic radiology the following were carried out: determination of the frequency of a procedure; measurement of patient doses using TLD and processing of data and calculation of gonadal and bone-marrow doses.

International Nuclear Information System (INIS)

Objective: To develop a computerized method of internal dose estimation on radiation protection. Methods: Based on MIRD mathematic model of the organs and by means of the programming language of MS Visual Basic 6.0, a computer program of dose estimation in internal radiation was developed for radiation protection. Results: The computerized method of dose estimation for internal radiation was completed. Conclusions: This computerized method is very convenient for internal radiation dose estimation of several aspects. It can also be used in radiation accident. (authors)

International Nuclear Information System (INIS)

A brief description of the physical process of dose enhancement effects produced by X-ray radiation on materials is given, with emphasis on the influence on electronic devices. The damages caused by X-ray radiation dose enhancement is more serious than that of #gamma#-ray with higher energy.

UK PubMed Central (United Kingdom)

Voxel-based prescriptions of deliberately non-uniform dose distributions based on molecular imaging, so-called dose painting or theragnostic radiation therapy, require specification of a transformation...Full Text Available

UK PubMed Central (United Kingdom)

Experiments were conducted to determine the dose response of rat bladder urothelium to a range of different single and fractionated intravesicular doses of the carcinogen, N-methyl-N-nitrosourea (MNU)....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The risks to human health from small doses of ionizing radiation raise questions which remain largely unanswered. This paper begins by explaining the historical background to this subject; it goes on to discuss recent developments and concludes with a personal view of the dose-reponse relationship. (author).

UK PubMed Central (United Kingdom)

Purpose:To investigate the clinical usage of dose verification of Helical Tomotherapy plans by using 2D-array ion chambers, and to develop an efficient way to validate the dose delivered...Full Text Available

International Nuclear Information System (INIS)

Using nitrogen-13 initial measurements have been made of rumen ammonia-nitrogen pool size and turnover, and rate of incorporation of ammonia into microbial protein. It is also feasible to measure the rate of incorporation of absorbed ammonia into urea and the appearance of label in saliva.

Science.gov (United States)

The Bureau of Mines performed chemical research to elaborate details of sulfur chemistry pertaining to the citrate flue gas desulfurization process in which sulfur dioxide (SO2), absorbed (as bisulfite ion) in a buffered sodium citrate solution, is reduce...

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) interim examination and maintenance (IEM) cell is used for the remote disassembly of irradiated fuel and material experiments. The absorber open-test assembly (AOTA) is a 12-m (40-ft)-long instrumented absorber (control-rod-material) test assembly. Its primary purpose is to characterize the FFTF control-rod-material reaction rate during reactor operation. Instrumentation allowed temperature and pressure measurements at various locations in several absorber pins during reactor operation. After residing several months in the reactor, the assembly was transferred to the IEM cell by the closed-loop ex-vessel machine (CLEM) for separation of the irradiated portion of the experiment from the instrument stalk. After separation, the 3.6-m (12-ft)-long assembly was processed through the sodium removal system and shipped off-site for examination. This success allowed the timely completion of a major ...

Science.gov (United States)

Mist eliminators for flue gas desulphurisation units remove liquid droplets entrained in the flue gas leaving the SO/sub 2/-absorber vessels. The commercial designs currently available are described.

Energy Technology Data Exchange (ETDEWEB)

High-purity and doped GaAs films have been grown by Liquid-phase epitaxy (LPE) for development of a blocked impurity band (BIB) detector for far-infrared radiation. The film growth process developed has resulted in the capability to grow GaAs with a net active impurity concentration below 1 x 10{sup 13} cm{sup -3}, ideal for the blocking layer of the BIB detector. The growth of n-type LPE GaAs films with donor concentrations below the metal-insulator transition, as required for the absorbing layer of a BIB detector, has been achieved. The control of the donor concentration, however, was found to be insufficient for detector production. The growth by LPE of a high-purity film onto a commercially grown vapor-phase epitaxial (VPE) n-type GaAs doped absorbing layer resulted in a BIB device that showed a significant reduction in the low-temperature dark current compared to the absorbing layer only. Extended optical response was ...

Science.gov (United States)

Page 1. Page 2. Page 3. Page 4. Page 5. Page 6. Page 7. Page 8. Page 9. Page 10. Page 11. Page 12. Page 13. Page 14. Page 15. Page 16. Page ...

Energy Technology Data Exchange (ETDEWEB)

Only half of the carbon dioxide produced by burning fossil fuels stays in the atmosphere. It is thought that the oceans absorb the rest. To understand the world's climate it is necessary to know how the atmosphere, ocean and biosphere interact.

International Nuclear Information System (INIS)

Tachyons fired into and absorbed by rotating black holes can violate the second and third laws of black hole physics. It is suggested that apparent break-downs of these laws in astrophysical black holes can indicate the existence of cosmic tachyons. (author).

International Nuclear Information System (INIS)

It is answered to a previous letter by Basano, and shown that the difficulties met by that author within ''Extended relativity'' do not exist, but are due to the erroneous assumption that a certain condition for tachyons to be absorbed by a macro-object is sufficient (whilst it is only a necessary one).

International Nuclear Information System (INIS)

Organ and tissue doses and integral doses in patients due to diagnostic x-ray examinations of the chest and of the head will be presented. These data have been obtained by measuring the dose distributions in man phantoms by LiF-dosimetry. The data will be compared with data obtained by Monte-Carlo calculations. To obtain average organ doses for a special type of examination for the population or for a specified subpopulation in the variation of the exposure, data due to the different techniques used by the different radiologists has to be known. Such data will be presented. The results of the investigation will be discussed in connection with the concept of the 'somatic significant.

Energy Technology Data Exchange (ETDEWEB)

This dissertation deals with membrane gas absorption in the application of CO{sub 2} removal by aqueous alkanolamines, using microporous PTFE hollow fiber membranes. A new lab-scale apparatus was constructed and an extensive experimental study executed to determine the performance of the membrane gas absorber, with aqueous solutions of monoethanolamine (MEA) and methyldiethanolamine (MDEA) as absorbents. The important operation parameters CO{sub 2} partial pressure, gas velocity, liquid velocity, temperature and liquid CO{sub 2} loading were systematically varied within the range typically experienced in a process for exhaust gas CO{sub 2}-removal

UK PubMed Central (United Kingdom)

The purpose of this study is to explain the unplanned longitudinal dose modulations that appear in helical tomotherapy (HT) dose distributions in the presence of irregular patient breathing....Full Text Available

Science.gov (United States)

A doubly Q-switched laser with both an acousto-optic (AO) modulator and a GaAs saturable absorber can obtain a more symmetric and shorter pulse with high pulse peak power, which has been experimentally proved. The key parameters of an optimally coupled doubly Q-switched laser with both an AO modulator and a GaAs saturable absorber are determined, and a group of general curves are generated for what we believe is the first time, when the single-photon absorption (SPA) and two-photon absorption (TPA) processes of GaAs are combined, and the Gaussian spatial distributions of the intracavity photon density and the initial population-inversion density as well as the influence of the AO Q-switch are considered. These key parameters include the optimal normalized coupling parameter, the optimal normalized GaAs saturable absorber parameters, and the normalized parameters of the AO Q-switch, which can maximize the output energy. ...

International Nuclear Information System (INIS)

A total dose hardening treatment is applied to SIMOX buried oxides. Total ionizing dose radiation testing is performed on fully-depleted transistors fabricated on both hardened and non-hardened substrates. At 200 krads x-ray dose, the front gate shift is reduced from -0.7 to -0.2 V for FETs built on the hardened wafers.

International Nuclear Information System (INIS)

Brief item.

International Nuclear Information System (INIS)

... radiation effects human populations low dose irradiation neoplasms radiation

International Nuclear Information System (INIS)

Russian 2009 p. 118 Ukraine Mazilov, AV Stadnik, IA NSC 'Kharkiv

Energy Technology Data Exchange (ETDEWEB)

Dose-dependent behavior of the infrared stimulated luminescence (IRSL) decay from NaCl has been studied experimentally using only one aliquot irradiated with a range of 2-200 Gy {beta}-radiation doses. It was observed that the maximum IRSL intensity has not changed by an increase in dose though the total intensity increased as expected. Considering the possible implications of our findings for dosimeter, the results were compared with the other studies and discussed.

International Nuclear Information System (INIS)

... pathological changes patients radiation protection radiotherapy diseases

International Nuclear Information System (INIS)

The risks from radiation exposure during radiological diagnosis has usually been estimated in relation to genetic changes. Relevant information has been expressed as the genetically significant dose. In this paper we attempt to produce an analogous measure for evaluating the somatic risk in the form of a somatically significant dose index for radiological and CT examinations. It is shown that, for both types of examination, the two risk factors may be entirely different. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Collective dose equivalent and population dose from occupational exposures in Japan, 1988 were estimated on the basis of a nationwide survey. The survey was conducted on annual collective dose equivalents by sex, age group and type of radiation work for about 0.21 million workers except for the workers in nuclear power stations. The data on the workers in nuclear power stations were obtained from the official report of the Japan Nuclear Safety Commission. The total number of workers including nuclear power stations was estimated to be about 0.26 million. Radiation works were subdivided as follows: medical works including dental; non-atomic energy industry; research and education; atomic energy industry and nuclear power station. For the determination of effective dose equivalent and population dose, organ or tissue doses were measured with a phantom experiment. ...

International Nuclear Information System (INIS)

... populations radiation doses RADIOACTIVE MATERIALS. SOMATICALLY

Energy Technology Data Exchange (ETDEWEB)

Single doses of lead (trace to 445 mg/kg) were administered per os to suckling and adult mice. Both groups exhibited dose-independent lead retention when doses of 4 to 445 mg/kg were administered. However, developmental differences in the fraction of initial dose (FID) retained were evident for all doses administered. A much larger FID was retained in both age groups following administration of carrier-free /sup 203/Pb. The results are consistent with a mechanism of gastrointestinal lead absorption comprising two or more processes. Developmental differences were also observed in organ lead concentration relative to whole body concentration for kidneys, skull and brain 6 days following lead administration. Lead retentions (relative to whole body retention) in brain and in bone were linearly related to dose of lead administered in both suckling and adult age ...

International Nuclear Information System (INIS)

Background: the authors report on the conception and first clinical application of a donut-shaped high-dose configuration for proton therapy (PT). This approach allows one to intensify target volume dose coverage for targets encompassing a critical, dose-limiting structure - like here, the cauda equina -, whilst delivering minimal dose to other healthy structures surrounding the target, thereby reducing the integral dose. Methods and results: intensity-modulated PT methods (IMPT) for spot scanning were applied to create and deliver a donut-shaped high-dose configuration with protons, allowing treating > 75% of the target with at least 95% of the prescribed dose of 72.8 CGE, whilst restricting dose to the cauda equina to 60-65 CGE. Integral dose was lower by a factor of 3.3 as compared to ...

International Nuclear Information System (INIS)

An attempt was made to quantify the radiation risk of diagnostic radiology. After a general introduction of terms as radiation damage, radiation risk and effective dose equivalent, based on publications of the ICRP, somatic dose indexes were computed for several radiologic investigations, that comprise organ doses committed to red bone marrow, lung, female breast and thyroid with and without considering the rest of the body. The dose for the rest of the body was assumed to be equal to the dose received by the red bone marrow, that is also distributed over the whole body. Neglecting the exposure of the rest of the body resulted in an insignificant increase in the estimated somatic risk, with its experimental determination not being necessary. (author).

Energy Technology Data Exchange (ETDEWEB)

In 1978 the Marshall Islands Radiological Safety Program was organized to perform radiation measurements and assess radiation doses for the people of the Bikini, Enewetak, Rongelap and Utirik Atolls. One of the major field components of this program is whole- body counting (WBC). WBC is used to monitor the quantity of gamma- emitting radionuclides present in individuals. A primary objective of the program was to establish {sup 137}Cesium body contents among the Enewetak, Rongelap and Utirik populations. {sup 137}Cs was the only gamma-emitting fission radionuclide detected in the 1,967 persons monitored. {sup 137}Cs body burdens tended to increase with age for both sexes, and were higher in males. The average {sup 137}Cs dose Annual Effective Dose for the three populations was as follows: For Enewetak, the dose was 22{+-}4 {mu}Sv. For Utirik, the dose was 33{+-} 3 {mu}Sv. Since 1985 ...

Energy Technology Data Exchange (ETDEWEB)

Safety assessments for clearance of H-beam and valves, main radioactive metal wastes in Kori nuclear power plants, were carried out to derivate a decontamination factor for satisfying the dose limits of clearance level (Maximum individual dose: 10 {mu}Sv/y, collective dose: 1 man{center_dot}Sv/y) in Korea. Maximum individual dose and collective dose were evaluated by internal dose conversion factor which based on the concept of effective dose in ICRP publication 60. The results of maximum individual dose and collective dose is 139 {mu}Sv per year and 0.166 man{center_dot}Sv per year about H-beam, and 158 {mu}Sv per year and 0.468 man{center_dot}Sv per year about valves respectively. Demand decontamination factor satisfied with, which is respectively more than 13.9 and 15.8 for satisfying clearance ...

International Nuclear Information System (INIS)

The determination of the dose to organs from diagnostic x rays has become important because of reports of radiation injury to patients from fluoroscopically guided interventional procedures. We have modified a convolution/superposition-based treatment planning system to compute the dose distribution for kilovoltage beams. We computed lung doses using this system and compared them to those calculated using the CDI3 organ dose calculation program. We also computed average lung doses from a simulated radiofrequency ablation procedure and compared our results to published doses for a similar procedure. Doses calculated using this system were an average of 20% lower for AP beams and 7% higher for PA beams than those obtained using CDI3. The ratio of the average dose to the lungs to the skin dose from the ...

CERN Document Server

Lyman-limit absorption systems can play many important roles during and after cosmological reionization. Unfortunately, due to the prohibitively large dynamic range required, it is impossible to self-consistently include these systems in cosmological simulations. Using fast and versatile semi-numeric simulations, we systematically explore the spatial distribution of absorption systems during and following reionization. We self-calibrate the resulting number of absorbers to the mean free path (mfp) of the ionizing ultraviolet background (UVB), and present results at a given mfp and neutral hydrogen fraction. We use a simple optical depth criterion to identify the locations of absorbers. Our approach is fairly robust to uncertainties such as missing subgrid structure. Unlike at lower redshifts where the UVB is relatively uniform, at higher redshifts the fluctuations in the UVB and the HII morphology of reionization can drive the large-scale ...

Science.gov (United States)

A possible receiver configuration is a cavity in which a falling sheet of solid particles is directly irradiated by the concentrated solar flux passing through the aperture. Regardless of the particular geometry, the radiative transfer within the falling particle curtain must be studied in order to determine the net radiative heating rate for the particles. A discrete ordinate radiative transfer model has been developed to predict the radiative coupling within the falling particle curtain. The model determines how much energy is absorbed by the particles, how much is transmitted to the rear wall of the receiver, and determines the effects of particle scattering and thermal emission on the net radiation absorbed by the particles. The model accounts for the directional nature of the radiation field, particle scattering, and the wavelength dependence of the optical properties. The discrete ordinate model has been used to assess the influence of ...

Energy Technology Data Exchange (ETDEWEB)

Peeled Avena sativa coleoptile sections have been used to study the control of solute uptake under conditions where the uptake is not limited by the cuticular barrier. In the presence of 2% sucrose, auxin enhances the rate at which the total osmotic solutes increase, but this appears to be a response to the increased growth rate, inasmuch as the auxin effect is eliminated when growth is inhibited osmotically. When sections are incubated in sucrose or in 10 millimolar NaCl, the osmotic concentration increases until a plateau is reached after 8 to 24 hours. Auxin has no effect on the initial rate of increase in osmotic concentration. This difference in steady-state osmotic concentration is, in part, a response to auxin itself, as it persists when auxin-induced growth is inhibited osmotically. The upper limit for osmotic concentration does not appear to be determined by the turgor pressure, inasmuch as a combination of sucrose and NaCl gave a higher plateau osmotic concentration than did ...

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Basic experimental investigations were carried out with an aqueous solution of a mixture of KOH and NaOH for use as an absorbent in absorption heat pumps. Due to its thermophysical properties this mixture allows temperature lifts from evaporator to absorber of more than 75 K (135 F) in a single-stage absorption chiller. Thermophysical and hydrodynamical properties of the solution were measured. Vapor-liquid-equilibrium data and specific heat capacities were determined for concentrations ranging from 35% up to 75% and temperatures up to 200 C (392 F). From these data the enthalpy of the solution was calculated. Additionally the crystallization temperatures, the density, and the viscosity of the solution were determined. The experimental equipment is described. The data are presented as polynomials and diagrams including experimental accuracy. An apparatus was constructed to measure heat and mass transfer coefficients of the absorption process ...

International Nuclear Information System (INIS)

Objective: To develop software for assessment of dose to thyroid gland in emergencies resulting in the release of radioiodine. Methods: Based on procedures for thyroid monitoring and dose assessment introduced in IAEA publications (IAEA-TECDOC-1092 and EPR-MEDICAL-2005), a software was developed with Visual Basic 6.0 program to computerized the methods of thyroid dose estimation. Results: The intake of radioiodine and committed equivalent dose to thyroid could be estimated rapidly and accurately with the present software. Conclusion: The present software provide a practical and rapid tool for estimating thyroid doses received in emergencies resulting in the release of radioiodine by emergency workers and members of public, which is necessary for recommendation of further actions. (authors)

Energy Technology Data Exchange (ETDEWEB)

When evaluating the risks of oncogenesis and cancer mortality following exposure to the radiations of the atomic bombs (A-bombs), the medical X-ray doses received by the A-bomb survivors must also be estimated and considered. Using a human phantom, dosimetry was performed to estimate the X-ray doses received by A-bomb survivors during medical examinations at the Radiation Effects Foundation (RERF) as part of the long-term follow-up on the Adult Health Study (AHS). These examinations have been estimated to represent nearly 45% of the survivors' cumulative medical irradiation dose. Doses to the salivary glands, thyroid gland, lung, breast, stomach and colon were measured using thermoluminescent dosemeters. The results, which are reported here, will aid in estimating organ doses received by individual AHS participants. (Author).

International Nuclear Information System (INIS)

Lifetime of minority charae carriers in the Si and Ge p-n unctions has been measured by pulse method of conductivity modulation of base. Its dependence on the X-ray radiation dose has been investigated. Dependence of current transmission coefficients on the dose has been measured and their sharp decrease at low doses and the following saturation at high doses have been observed. Linear dependence of lifetime on X-ray radiation dose has been obtained. Resulting from the comparison of regularities of the change of lifetime due to current characteristics, it has been shown that X-ray radiation leads to the formation of the surface defects, influencing the change of current characteristics as well as to stationary structural defects, causing the decrease of lifetime of the charge carriers with the increase of X-ray radiation dose.

Energy Technology Data Exchange (ETDEWEB)

This study investigated dose to bone tissue in electron beam therapy. Measurements were made using films and thermoluminescent dosimeters in a polystyrene phantom containing bone inhomogeneity for 15-MeV, 12-MeV, and 9-MeV electron beams. An increase in dose of approximately 18%, 12%, and 11%, for the three electron energies respectively, relative to the dose in polystyrene, was found for bone material having an electron density (relative to water) of 1.73. Measurements were also made using films for 15- and 9-Mev electrons in a phantom with a mandibular bone and teeth. A dose enhancement in bone of approximately 10% and 7%, respectively, for the two energies was found in the phantom where the electron density of bone was about 1.60. These results suggest that injury to bone is possible in those clinical situations where high doses of electrons are used for therapy.

International Nuclear Information System (INIS)

The Monte Carlo method is used to analyse the dose fall-off at the exit surface of a megavoltage photon beam. The convolution/superposition method of dose calculation using Monte-Carlo-generated homogeneous photon kernels is shown to be in error for exit dose calculation. Instead, photon kernels that incorporate modelling of the exit surface were generated, also using Monte Carlo, to analyse the problem, and the calculated dose fall-off using these kernels agrees well with measured data. In addition, the physics underlying the characteristics of the dose fall-off is analysed based on complete Monte Carlo modelling. Practical improvements to the convolution/superposition method are suggested. (Author).

Energy Technology Data Exchange (ETDEWEB)

A solar energy desalination process utilizing solar radiation directly for the evaporation of salt water is described. Ambient air takes on water vapor as the air passes through an evaporative medium. It is then directed between a saline water-covered, solar absorbing surface and a solar collecting housing. The resulting heated and moisture-saturated air is cooled in a heat exchange means where condensation of fresh water occurs. Simultaneously, cool salt water is utilized as the cooling water in the heat exchange means, and takes on the heat of condensation given up by the condensing vapor. The heated salt water from the heat exchange means is partially directed over the solar absorbing surface, and at least a portion of it is also directed to wet the evaporative medium. Several optional sub-processes are described for operation of the system during periods of reduced insolation, and an alternative process is described for operation of the ...

Science.gov (United States)

A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

Energy Technology Data Exchange (ETDEWEB)

In this work, a comprehensive model has been developed for the absorption of carbon dioxide into promoted hot potassium carbonate solution. The model, which is based on penetration theory, incorporates an extensive set of important reactions and takes into account the coupling between mass transfer and chemical kinetics. The penetration theory provides an appropriate absorption rate and enhancement factor for the chemical absorption. Operating data for carbon dioxide absorption into DEA-hot potassium carbonate solution has been compared with model predictions. The impact of parameters such inlet temperature of lean solution, promoter concentration, liquid split fraction, hot feed location and type of promoter on the performance of a split-flow absorber have been examined. The use of other promoters is an efficient way to enhance the carbon dioxide absorption, which has been discussed in this paper.

Energy Technology Data Exchange (ETDEWEB)

The interaction of thermal radiation with conduction and convection in thermally developing absorbing, emitting, non-gray gas particulate turbulent suspension flow through a circular tube is investigated. The contribution of thermal radiation is obtained through evaluation of the total hemispherical emittance of the particulate cloud and through evaluation of single band absorptances for molecular gases, modified to account for the interaction with the particles. The governing differential equation is derived as a (nonlinear) energy equation, coupled with integral equations to find the thermal radiation contributions. The energy equation is solved numerically by an implicit finite difference with its iterative procedure. Qualitative results for Nusselt numbers are shown for a variety and range of parameters, such as optical thickness of particulates and single molecular gas bands, relative gas band position and band width, and temperature ratios (heated as well as ...

Energy Technology Data Exchange (ETDEWEB)

The absorption of carbonyl sulfide in aqueous methyldiethanolamine (MDEA) was studied over a range of temperatures and MDEA concentrations. MDEA is commonly used for selective absorption of hydrogen sulfide in the presence of carbon dioxide. However, sulfur in the form of COS may also be present and it is necessary that estimates of absorption rates of this compound be made. The objective of this study is to determine the physiochemical properties needed to predict COS absorption rates in aqueous MDEA. Free gas solubility and the diffusivity of COS in MDEA solutions were measured over the temperature range 15 to 40{sup 0}C for MDEA concentrations up to 30 weight per cent using the nitrous oxide analogy method. Solubilities were measured volumetrically in an equilibrium cell and diffusivities were measured using a laminar liquid jet absorber. The kinetics of the reaction between COS and MDEA were studied by measuring absorption rates in a single wetted-sphere ...

Energy Technology Data Exchange (ETDEWEB)

We present a collisional-radiative approach of the theoretical analysis of laser-induced breakdown spectroscopy (LIBS) plasmas. This model, which relies on an optimized effective potential atomic structure code, was used to simulate a pure aluminum plasma. The description of aluminum involved a set of 220 atomic levels representative of three different stages of ionization (Al{sup 0}, Al{sup +} and Al{sup ++}). The calculations were carried for stationary plasmas, with input parameters (n{sub e} and T{sub e}) ranging respectively between 10{sup 13-18} cm{sup -3} and 0.3-2 eV. A comparison of our atomic data with some existing databases is made. The code was mainly developed to address the validity of the local thermodynamic equilibrium (LTE) assumption. For usual LIBS plasma parameters, we did not reveal a sizeable discrepancy of the radiative equilibrium of the plasma towards LTE. For cases where LTE was firmly believed to stand, the Boltzmann plot outputs of this code were used to ...

International Nuclear Information System (INIS)

The nuclear activity was conducted for many years in Romania under Traditional Safeguards (TS) and has developed in good conditions the specific nuclear safeguards. Now there is a good opportunity to improve the performance and quality of the safeguards activity and at the same time to increase the accountancy and control of nuclear materials by passing to Integrated Safeguards (IS) implementation. The legal framework is the Law 100/2000 for ratification of the Protocol between Romania and International Atomic Energy Agency (IAEA), additional completion to the Agreement between the Socialist Republic of Romania Government and IAEA relating to safeguards. It is part of the Treaty on the non-proliferation of nuclear weapons published in the Official Gazette no. 3/31 January 1970, and the Additional Protocol published in the Official Gazette no. 295/ 29.06.2000. The first discussion about Integrated Safeguards (IS) between the Nuclear Fuel Plant (FCN) representatives and IAEA inspectors ...

International Nuclear Information System (INIS)

For the lifetime evaluation of plasma facing materials in fusion experimental machines, it is essential to investigate their surface behavior and their temperature responses during an off-normal event such as the plasma disruptions. An infrared thermometer with a sampling speed as fast as 1x10"-"6 s/data, namely, the high-speed infrared thermometer (HSIR), has been developed by the National Research Laboratory of Metrology in Japan. To evaluate an applicability of the newly developed HSIR on the surface temperature measurement of plasma facing materials, high heat flux beam irradiation experiments have been performed with three different materials under the surface heat fluxes up to 170 MW/m"2 for 0.04 s in a hydrogen ion beam test facility at the Japan Atomic Energy Research Institute. As for the results, HSIR can be applicable for measuring the surface temperature responses of the armor tile materials with a little modification. It is also confirmed that surface ...

International Nuclear Information System (INIS)

The Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, developed an alignment strategy to specify elemental depth profiling in vertical sidewall layers on structured wafers. For this purpose, PTB's irradiation chamber for 200 mm and 300 mm silicon wafers was used to combine total-reflection X-ray fluorescence (TXRF) and grazing incidence XRF (GIXRF) techniques by employing monochromatized undulator radiation of the BESSY II electron storage ring. 3-D test structures were fabricated to develop an optimal alignment strategy allowing for depth profiling in such nanolayers. The test structures consisted of silicon bars with widths/spacings either in the ?m or in the nm range. In order to be able to differentiate the sidewalls more easily from the remainder of the structures, they were provided with an additional silicon nitride layer. Four structure types of different bar width and density parameters on two 200 mm silicon wafers were ...

UK PubMed Central (United Kingdom)

For intensity modulated radiation treatment (IMRT) dose reconstruction, multileaf collimator (MLC) log files have been shown applicable for deriving delivered fluence maps. However, MLC log files are...Full Text Available

International Nuclear Information System (INIS)

We developed a new TLD array for precise dose measurement and verification of the spatial dose distribution in small radiation targets. It consists of a hemicylindrical, tissue-equivalent rod made of polystyrene with 17 parallel moulds for an exact positioning of each TLD. The spatial resolution of the TLD array was evaluated using the Leskell spherical phantom. Dose planning was performed with KULA 4.4 under stereotactic conditions on axial CT images. In the Leksell gamma unit the TLD array was irradiated with a maximal dose of 10 Gy with an unplugged 14 mm collimator. The doses delivered to the TLDs were rechecked by diode detector and film dosimetry and compared to the computer-generated dose profile. We found excellent agreement of our measured values, even at the critical penumbra decline. For the 14 mm and 18 mm collimator and for the 11 mm collimator ...

UK PubMed Central (United Kingdom)

The pharmacokinetics of ceftriaxone were investigated in six healthy mainland Chinese adults (four males and two females). A single 1.0-g dose was administered intravenously or intramuscularly in a...Full Text Available

UK PubMed Central (United Kingdom)

AimsTo assess the tolerability and pharmacokinetic profile of single and repeat doses of the oral matrix metalloproteinase inhibitor marimastat in healthy male volunteers.Full Text Available

International Nuclear Information System (INIS)

The achievements made in the field of radiation protection over the past 20 years are outlined. Risk analysis as applied to medicine is considered and genetic significant doses, genetic risks, somatic effective doses and somatic risks are discussed. (C.F.).

UK PubMed Central (United Kingdom)

BackgroundThe aim of this study was to compare and to validate different dose calculation algorithms for the use in radiation therapy of small lung lesions and to optimize the treatment...Full Text Available

UK PubMed Central (United Kingdom)

AbstractMilk residues and performance were evaluated in lactating cows that were fed up to 10 times the recommended dose of monensin. Following an acclimatization period of 14 d, during...Full Text Available

International Nuclear Information System (INIS)

For the risk estimate of fatal malignancies, an effective dose was proposed on the basis of the assumption that the risk should be equal whether the whole body irradiated uniformly or whether there is non-uniform irradiation. The effective dose was defined by the product of organ or tissue doses and a weighting factor representing the proportion of risk factor for a fatal malignancy resulting from organ or tissue irradiation to the total malignant factor. The risk of malignancies can be derived by multiplying the malignant significant factor by the product of the risk factor and the effective dose. For the genetic risk, a significant factor was a relative child expectancy and organ or tissue doses were gonad doses. And, for the leukemogenic risk, a significant factor was the leukemia significant factor and organ or tissue dose was mean bone ...

UK PubMed Central (United Kingdom)

Objective:In this article, we describe a successful low-dose, off-label usage of drotrecogin alfa (Xigris), given at 18 mcg/kg per hour, in a patient with severe sepsis who had an...Full Text Available

International Nuclear Information System (INIS)

Rats were exposed to aerosols of "2"3"3U and "2"3"2U nitrate in a study of the long-term biological effects. Preliminary radiation dose estimates show lung > skeleton > kidney in each dose group.

UK PubMed Central (United Kingdom)

1. The effect of three single doses of nifedipine on exercise-induced asthma has been examined in 11 asthmatic subjects. 2. On four separate days patients undertook 6 min of exercise on a treadmill...Full Text Available

International Nuclear Information System (INIS)

IMRT optimization requires a fast yet relatively accurate algorithm to calculate the iteration dose with small memory demand. In this paper, we present a dose calculation algorithm that approaches these goals. By decomposing the infinitesimal pencil beam (IPB) kernel into the central axis (CAX) component and lateral spread function (LSF) and taking the beam's eye view (BEV), we established a non-voxel and non-beamlet-based dose calculation formula. Both LSF and CAX are determined by a commissioning procedure using the collapsed-cone convolution/superposition (CCCS) method as the standard dose engine. The proposed dose calculation involves a 2D convolution of a fluence map with LSF followed by ray tracing based on the CAX lookup table with radiological distance and divergence correction, resulting in complexity of O(N"3) both spatially and temporally. This simple algorithm is orders ...

Energy Technology Data Exchange (ETDEWEB)

This volume presents the collations tables of a six volume comparative epidemiological survey of the effects of low level radiation dose. Data are collated for the effects observed in the following irradiated groups:- Preconception irradiation, intra-uterine irradiation, childhood irradiation, adult irradiation. (UK).

Energy Technology Data Exchange (ETDEWEB)

Ionising radiation induces stable free radicals in chicken bones and in the shell of chicken eggs which can be detected, by the electrons spin resonance (ESR) technique, well beyond the shelf-life of the food and can be used for dosimetry. The method usually adopted to evaluate ``a posteriori`` the dose given during the ionising radiation treatment of food, is the dose additive method. To assess the dose, the ESR signal amplitude of the irradiated food (bone or egg shell in the present case) is measured and then the dose-effect relationship is obtained by re-irradiating the sample with some additive doses (usually of 1 kGy). The dose-effect curve is back-extrapolated and the initial given dose determined. At the Istituto Superiore di Sanita (ISS), Rome, Italy, a research programme was approved two years ago aimed to, (1) study new ...

UK PubMed Central (United Kingdom)

IntroductionThe optimal dialysis dose for the treatment of acute kidney injury (AKI) is controversial. We sought to evaluate the relationship between renal replacement therapy (RRT)...Full Text Available

UK PubMed Central (United Kingdom)

Background/AimTobacco use reduces the effect of non-surgical periodontal therapy. Host-modulation with low-dose doxycycline (LDD) might favour repair and promote...Full Text Available

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

The authors give a survey of the somatic radiation risk in X-ray diagnostics. A somatic dose index is calculated for different examination methods containing the organ doses to the red bone marrow, the lung, the female breast, and the thyroid gland and evaluating their somatic significance. If this somatic dose index by which the individual radiation risk is described, is multiplied by the examination frequencies per year in the German Federal Republic, one gets the somatically significant dose index, which is a measure of the collective somatic radiation risk. In this sense, mammography has the highest, and dental radiography the lowest collective radiation risk.

Science.gov (United States)

... Title : Serum Creatine Phosphokinase Activity after Intramuscular Injection: The Effect of Dose, Concentration, and Volume. ...

Energy Technology Data Exchange (ETDEWEB)

Health physicists from the Brookhaven National Laboratory (BNL) visited the Savannah River Site (SRS) as one of 12 facilities operated by the Department of Energy (DOE) contractors with annual collective dose equivalents greater than 100 person-rem (100 person-cSv). Their charter was to review, evaluate and summarize as low as reasonably achievable (ALARA) techniques, methods and practices as implemented. This presentation gives an overview of the two selected ALARA practices implemented at the SRS: Administrative Exposure Limits and Goal Setting. These dose control methods are used to assure that individual and collective occupational doses are ALARA and within regulatory limits.

International Nuclear Information System (INIS)

An important unresolved issue in outcomes analysis for lung complications is the effect of poor or completely lacking heterogeneity corrections in previously archived treatment plans. To estimate this effect, we developed a novel method based on Monte Carlo (MC) dose calculations which can be applied retrospectively to RTOG/AAPM-style archived treatment plans (ATP). We applied this method to 218 archived nonsmall cell lung cancer lung treatment plans that were originally calculated either without heterogeneity corrections or with primitive corrections. To retrospectively specify beam weights and wedges, beams were broken into Monte Carlo-generated beamlets, simulated using the VMC++ code, and mathematical optimization was used to match the archived water-based dose distributions. The derived beam weights (and any wedge effects) were then applied to Monte Carlo beamlets regenerated based on the patient computed tomography densities. Validation ...

Energy Technology Data Exchange (ETDEWEB)

Contributions to the population dose due to medical applications of ionising radiation are presented. It appears that contributions due to radiotherapy and X ray diagnosis are of comparable magnitude. To account for the age dependency of the radiation risks, contributions in terms of somatically significant dose equivalent are calculated as 0.3 mSv per caput per annum for X ray diagnosis and as 0.2 mSv per caput per annum for radiotherapy, the latter referring to only doses to organs outside the target volume. (author).

International Nuclear Information System (INIS)

Doses to the salivary glands, thyroid gland, breast, lung, stomach and colon during mass radiological gastric screening, mass radiographic chest screening, upper gastrointestinal series and computed tomography were determined by exposing a female human phantom to simulated radiological X-ray examinations as performed in community hospitals. The doses were measured using thermoluminescent dosemeters, and the results will be used to document organ doses received by participants in the Atomic Bomb Casualty Commission/Radiation Effects Research Foundation Adult Health Study. (Author).

International Nuclear Information System (INIS)

... americium 241 americium 242 beta decay chain reactions integral doses mass

International Nuclear Information System (INIS)

Background and purpose: The low density of lung tissue causes a reduced attenuation of photons and an increased range of secondary electrons, which is inaccurately predicted by the algorithms incorporated in some commonly available treatment planning systems (TPSs). This study evaluates the differences in dose in normal lung tissue computed using a simple and a more correct algorithm. We also studied the consequences of these differences on the dose-effect relations for radiation-induced lung injury. Materials and methods: The treatment plans of 68 lung cancer patients initially produced in a TPS using a calculation model that incorporates the equivalent-pathlength (EPL) inhomogeneity-correction algorithm, were recalculated in a TPS with the convolution-superposition (CS) algorithm. The higher accuracy of the CS algorithm is well-established. Dose distributions in lung were compared using isodoses, ...

Science.gov (United States)

However, market based pricing doses not apply where the pricing .... the reimbursable work, market based pricing does not apply. 040202. ...

International Nuclear Information System (INIS)

A compartment model is described which is currently used by the Ministry of Agriculture, Fisheries and Food to calculate collective radiation exposure due to liquid radioactive wastes discharged to sea from UK nuclear sites. Collective dose is a useful indicator of the radiological impact of a disposal practice and is one of the quantities needed to show compliance with the ICRP system of dose limitation. The model has been used for the purposes of the Sizewell Inquiry to predict the collective radiation exposure from reactor operation at Sizewell and, on the basis of current Sellafield experience, correlations between dose and discharge for disposals of fuel reprocessing wastes. (author).

International Nuclear Information System (INIS)

The radiation burden of the people of the GDR in relation to biomedical radiography altogether as well as organ doses, gonad doses and genetically significant doses in detail are outlined. The concepts of radiation protection and standards of radiographic examination are demonstrated. Possibilities of influencing radiation exposure by scientifically based indication of X-ray examination, application of new and improvement of usual examination techniques are discussed with regard to quality assurance and control. Proposals concerning the reduction of radiation exposure of the GDR population are presented.

International Nuclear Information System (INIS)

As a series of estimations of population doses and of risk estimates from medical exposures in Japan, the malignancy significant dose (MSD) and the fatal malignant risk from beam therapy were estimated based on a nationwide survey of radiotherapeutic treatments, using a malignancy significant factor and a weighting factor determined from the data on the cancer mortality among the atomic bomb survivors in Nagasaki. The effective dose was defined as a sum of the product of the weighting factor and the organ or tissue doses with respect to the malignant diseases. The organ or tissue doses were determined with ionization chambers placed at the positions of their center in a MixDp-phantom simulated lung tissues by a block of cork, using a telecobalt unit, a conventional X-ray unit and a medical linear accelerator. The organ or tissue doses were categorized into three ...

International Nuclear Information System (INIS)

This paper introduces an occupational exposure information system in detail, which is developed and in operation presently by Daya Bay nuclear power plant. It is presented in the paper that individual dose monitoring items and method, design and classification of database configuration, statistics and analysis of individual dose, and management of staff entering and exiting controlled area. The system is instructive to analysing individual dose and optimizing radiation protection measures. (authors)

International Nuclear Information System (INIS)

Analytical expressions for thermoluminescence (TL) dating based on the modified Zimmerman model were derived. The non-linear behaviour of TL sensitivity is reexamined and is found to be due to electron capturing competitions in both test-dose excitation and the readout stages. A curve fitting method is proposed to determine the paleodose for the additive dose dating method. The multiple activation technique is also investigated, from which the paleodose should be regarded as an upper limit.

Energy Technology Data Exchange (ETDEWEB)

Biomedical science researchers often express frustration that health physics practices vary widely between individual institutions. A survey examining both internal and external dose assessment practices was devised and mailed to fifty institutions supporting biomedical science research. The results indicate that health physics dose assessment practices and policies are highly variable. Factors which may contribute to the degree of variation are discussed. 2 tabs.

International Nuclear Information System (INIS)

This article introduces the composition, monitoring methods and working principles of environmental #gamma# dose rate continuous monitoring system at Guangdong Daya Bay Nuclear Power Station. The #gamma# dose rate monitoring status after modification of measurement conditions is introduced too.

UK PubMed Central (United Kingdom)

BackgroundSeveral studies have demonstrated the efficacy of artemisinin-combination therapy (ACT) across malaria zones of the world. Fixed dose ACT with shorter courses and fewer...Full Text Available