WorldWideScience

Sample records for nondestructive dose determination

  1. Concealed identification symbols and nondestructive determination of the identification symbols

    Science.gov (United States)

    Nance, Thomas A.; Gibbs, Kenneth M.

    2014-09-16

    The concealing of one or more identification symbols into a target object and the subsequent determination or reading of such symbols through non-destructive testing is described. The symbols can be concealed in a manner so that they are not visible to the human eye and/or cannot be readily revealed to the human eye without damage or destruction of the target object. The identification symbols can be determined after concealment by e.g., the compilation of multiple X-ray images. As such, the present invention can also provide e.g., a deterrent to theft and the recovery of lost or stolen objects.

  2. Nondestructive NMR technique for moisture determination in radioactive materials

    International Nuclear Information System (INIS)

    Aumeier, S.; Gerald, R.E. II; Growney, E.; Nunez, L.; Kaminski, M.

    1998-01-01

    This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei ( 3 H, 3 He, 239 Pu, 241 Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO 2 and UO 2 systems. The total moisture was quantified by means of 1 H NMR detection of H 2 O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96

  3. Dose determination in computed tomography

    International Nuclear Information System (INIS)

    Descamps, C.; Garrigo, E.; Venencia, D.; Gonzalez, M.; Germanier, A.

    2011-10-01

    In the last years the methodologies to determine the dose in computed tomography have been revised. In this work was realized a dosimetric study about the exploration protocols used for simulation of radiotherapy treatments. The methodology described in the Report No. 111 of the American Association of Medical Physiques on a computed tomograph of two cuts was applied. A cylindrical phantom of water was used with dimensions: 30 cm of diameter and 50 cm of longitude that simulates the absorption and dispersion conditions of a mature body of size average. The doses were determined with ionization chamber and thermoluminescent dosimetry. The results indicate that the dose information that provides the tomograph underestimates the dose between 32 and 35%.

  4. Evaluation of the MIT-Scan-T2 for non-destructive PCC pavement thickness determination.

    Science.gov (United States)

    2008-07-01

    The MIT-Scan-T2 device is marketed as a non-destructive way to determine pavement thickness on both : HMA and PCC pavements. PCC pavement thickness determination is an important incentivedisincentive : measurement for the Iowa DOT and contractors. Th...

  5. Non-Destructive Technique for Determining Mango Maturity

    OpenAIRE

    Salengke; Mursalim

    2013-01-01

    Mango (Mangifera indica L.) is an important tropical fruit that has great potential in international markets. Currently, major markets for mango include North America, Europe, and Japan. The acceptance of exported mango in destination countries depends largely on eating quality, which is affected by maturity at harvest. Mango maturity can be judged visually, based on skin color, or determined chemically based on soluble solids content, acid content, and solids:acid ratio....

  6. Determination of in-depth contamination in concrete using a non-destructive technique

    International Nuclear Information System (INIS)

    Boden, S.; Cantrel, E.

    2007-01-01

    The decommissioning of the BR3 (Belgian Reactor 3) approaches its final phase, in which the building structures are being decontaminated and either denuclearized for possible reuse or demolished. Apart from the presence of naturally occurring radionuclides in building materials, other radionuclides might be present due to activation or contamination. The BR3 bioshield has been exposed to rather high neutron leakage fluxes during the reactor operation and is therefore activated. Building structure contamination usually results from leakages during reactor operation, releases due to maintenance works or even dismantling operations. In case of in-depth contamination in concrete it is important to know the exact in-depth profile before decontamination, in order to minimize the amount of radioactive waste that will be produced during the decontamination process and to optimize both the decontamination process and the final control measurements. Common non-destructive analyses used in decommissioning are usually based on the measurement of beta radiation, using e.g. hand-held plastic scintillators. This kind of measurement technique can not be used to determine in-depth contamination. Therefore, most of the decontamination specialists currently base themselves on the results of the radiological analysis of samples taken by core drilling. The use of such a destructive method implies a number of disadvantages: it is time consuming and therefore costly and the different sample preparation steps can conceivably lead to cross-contamination. Moreover, one only receives results of a limited number of points, while the in-depth contamination is usually very inhomogeneously distributed and the relationship between in-depth contamination and surface contamination and/or dose rate (hotspot detection) is generally rather poor.The objective therefore is to test the use of the ISOCS (In Situ Object Counting System) for the determination of contamination depth

  7. The use of magnetic Barkhausen noise analysis for nondestructive determination of stresses in structural elements

    International Nuclear Information System (INIS)

    Silva Junior, Silverio Ferreira da; Mansur, Tanius Rodrigues; Cruz, Julio Ricardo Barreto

    2007-01-01

    The knowledge about the stress state acting in structural elements has significant importance in the structural integrity evaluation of a specific component. The magnetic Barkhausen noise analysis can be used for this purpose. As a nondestructive testing method, it presents the advantage of not promote any changes in the tested component. In this paper, a study about the use of this new nondestructive test method for stress measurements is presented. The test system configuration and the reference standards used for this purpose, as well as the optimum test parameters determination are discussed. The experiments were carried out in ASTM A-36 steel, used for structural components manufacturing. A structure of this material was loaded and the resulting stresses were determined from strain gage measurements and Barkhausen noise analysis. The results obtained have showed a good sensitivity of the magnetic Barkhausen noise to stress changes occurred in the material. The main advantages and limitations of this test method for stress measurements are presented. (author)

  8. Nondestructive and intuitive determination of circadian chlorophyll rhythms in soybean leaves using multispectral imaging

    Science.gov (United States)

    Pan, Wen-Juan; Wang, Xia; Deng, Yong-Ren; Li, Jia-Hang; Chen, Wei; Chiang, John Y.; Yang, Jian-Bo; Zheng, Lei

    2015-01-01

    The circadian clock, synchronized by daily cyclic environmental cues, regulates diverse aspects of plant growth and development and increases plant fitness. Even though much is known regarding the molecular mechanism of circadian clock, it remains challenging to quantify the temporal variation of major photosynthesis products as well as their metabolic output in higher plants in a real-time, nondestructive and intuitive manner. In order to reveal the spatial-temporal scenarios of photosynthesis and yield formation regulated by circadian clock, multispectral imaging technique has been employed for nondestructive determination of circadian chlorophyll rhythms in soybean leaves. By utilizing partial least square regression analysis, the determination coefficients R2, 0.9483 for chlorophyll a and 0.8906 for chlorophyll b, were reached, respectively. The predicted chlorophyll contents extracted from multispectral data showed an approximately 24-h rhythm which could be entrained by external light conditions, consistent with the chlorophyll contents measured by chemical analyses. Visualization of chlorophyll map in each pixel offers an effective way to analyse spatial-temporal distribution of chlorophyll. Our results revealed the potentiality of multispectral imaging as a feasible nondestructive universal assay for examining clock function and robustness, as well as monitoring chlorophyll a and b and other biochemical components in plants. PMID:26059057

  9. Calculation methods for determining dose equivalent

    International Nuclear Information System (INIS)

    Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

    1987-11-01

    A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. Critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 [1] methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed. The effective dose equivalent determined using ICRP-26 methods is significantly smaller than the dose equivalent determined by traditional methods. No existing personnel dosimeter or health physics instrument can determine effective dose equivalent. At the present time, the conversion of dosimeter response to dose equivalent is based on calculations for maximal or ''cap'' values using homogeneous spherical or cylindrical phantoms. The evaluated dose equivalent is, therefore, a poor approximation of the effective dose equivalent as defined by ICRP Publication 26. 3 refs., 2 figs., 1 tab

  10. Nondestructive determination of nutritional information in oilseed rape leaves using visible/near infrared spectroscopy and multivariate calibrations

    NARCIS (Netherlands)

    Liu Fei, [No Value; Nie PengCheng, [No Value; Huang Min, [No Value; Kong WenWen, [No Value; He Yong, [No Value

    Nitrogen, phosphorus and potassium content are the three most important nutritional parameters for growing oilseed rape. We investigated visible and near infrared (Vis/NIR) spectroscopy combined with chemometrics for the fast and nondestructive determination of nutritional information in oilseed

  11. Nondestructive Determination of Reinforcement Volume Fractions in Particulate Composites : Ultrasonic Method

    International Nuclear Information System (INIS)

    Jeong, Hyun Jo

    1998-01-01

    A nondestructive ultrasonic technique is presented for estimating the reinforcement volume fractions of particulate composites. The proposed technique employs a theoretical model which accounts for composite microstructures, together with a measurement of ultrasonic velocity to determine the reinforcement volume fractions. The approach is used for a wide range of SiC particulate reinforced Al matrix (SiC p /AI) composites. The method is considered to be reliable in determining the reinforcement volume fractions. The technique could be adopted in a production unit for the quality assessment of the metal matrix particulate composite extrusions

  12. Determination of organ doses and effective doses in radiooncology

    International Nuclear Information System (INIS)

    Roth, J.; Martinez, A.E.

    2007-01-01

    Background and Purpose: With an increasing chance of success in radiooncology, it is necessary to estimate the risk from radiation scatter to areas outside the target volume. The cancer risk from a radiation treatment can be estimated from the organ doses, allowing a somewhat limited effective dose to be estimated and compared. Material and Methods: The doses of the radiation-sensitive organs outside the target volume can be estimated with the aid of the PC program PERIDOSE developed by van der Giessen. The effective doses are determined according to the concept of ICRP, whereby the target volume and the associated organs related to it are not taken into consideration. Results: Organ doses outside the target volume are generally < 1% of the dose in the target volume. In some cases, however, they can be as high as 3%. The effective doses during radiotherapy are between 60 and 900 mSv, depending upon the specific target volume, the applied treatment technique, and the given dose in the ICRU point. Conclusion: For the estimation of the radiation risk, organ doses in radiooncology can be calculated with the aid of the PC program PERIDOSE. While evaluating the radiation risk after ICRP, for the calculation of the effective dose, the advanced age of many patients has to be considered to prevent that, e.g., the high gonad doses do not overestimate the effective dose. (orig.)

  13. A nondestructive testing device for determining 235U enrichment in power reactor fuel elements

    International Nuclear Information System (INIS)

    Liu Lanhua; Liu Nangai

    1990-07-01

    The development and application of a nondestructive testing device are presented, which is used for determining the 235 U enrichment in the mixed fuel of fuel elements with UO 2 pellets. The testing efficiency is improved because the passive gamma ray method and a hole-bored NaI crystal and four channel multichannel analyzer are used. The false discrimination rate is reduced as the average comparing method is taken. This device is simple in structure and easy in operation. It has provided a new testing tool for the fuel elements production in China. This device has successfully been used in Qinshan Nuclear Power Plant in testing its fuel elements

  14. Nondestructive determination of burnup and fissile isotope balance in spent fuel assemblies of water cooled reactors

    International Nuclear Information System (INIS)

    Pinel, J.

    1983-03-01

    Two non-destructive methods for measuring fuel assemblies in storage pools have been developed: a gamma fuel scanning method, using the 134 Cs - 137 Cs and 144 Ce gamma rays, and the measurement of the neutron flux emitted by the fuel assembly. For interpreting the measurement, we have used calculated correlations to establish a connection between the measured phenomena and the parameters to be determined. A measurement campaign involving 58 assemblies from the C.N.A. reactor was conducted in the reprocessing plant of LA HAGUE. The results obtained show that the objectives can be achevied within an industrial environment [fr

  15. An accurate and nondestructive GC method for determination of cocaine on US paper currency.

    Science.gov (United States)

    Zuo, Yuegang; Zhang, Kai; Wu, Jingping; Rego, Christopher; Fritz, John

    2008-07-01

    The presence of cocaine on US paper currency has been known for a long time. Banknotes become contaminated during the exchange, storage, and abuse of cocaine. The analysis of cocaine on various denominations of US banknotes in the general circulation can provide law enforcement circles and forensic epidemiologists objective and timely information on epidemiology of illicit drug use and on how to differentiate money contaminated in the general circulation from banknotes used in drug transaction. A simple, nondestructive, and accurate capillary gas chromatographic method has been developed for the determination of cocaine on various denominations of US banknotes in this study. The method comprises a fast ultrasonic extraction using water as a solvent followed by a SPE cleanup process with a C(18) cartridge and capillary GC separation, identification, and quantification. This nondestructive analytical method has been successfully applied to determine the cocaine contamination in US paper currency of all denominations. Standard calibration curve was linear over the concentration range from the LOQ (2.00 ng/mL) to 100 microg/mL and the RSD less than 2.0%. Cocaine was detected in 67% of the circulated banknotes collected in Southeastern Massachusetts in amounts ranging from approximately 2 ng to 49.4 microg per note. On average, $5, 10, 20, and 50 denominations contain higher amounts of cocaine than $1 and 100 denominations of US banknotes.

  16. Possibilities of nondestructive determination of fluorine in coal and biological materials by IPAA

    International Nuclear Information System (INIS)

    Randa, Zdenek; Mizera, Jiri; Chvatil, David

    2009-01-01

    The possibilities of nondestructive determination of fluorine in coal and biological materials by instrumental photon activation analysis (IPAA) were studied. The determination was based on counting the non-specific 511 keV annihilation gamma rays of 18 F, a pure positron emitter which is the product of the photonuclear reaction 19 F(γ, n) 18 F. The simultaneous formation of some additional positron emitters, particularly 45 Ti and 34m Cl, is an interfering factor. When using correction standards for Ti and Cl and optimization of the beam energy and irradiation-decay-counting times, fluorine could be determined by IPAA in selected coal and biological samples at the ten ppm level. The feasibility of additional optimization for further improvements of the proposed IPAA procedure are discussed

  17. Calculation methods for determining dose equivalent

    International Nuclear Information System (INIS)

    Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

    1988-01-01

    A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed

  18. Non-destructive testing method for determining the solvent diffusion coefficient in the porous materials products

    Science.gov (United States)

    Belyaev, V. P.; Mishchenko, S. V.; Belyaev, P. S.

    2018-01-01

    Ensuring non-destructive testing of products in industry is an urgent task. Most of the modern methods for determining the diffusion coefficient in porous materials have been developed for bodies of a given configuration and size. This leads to the need for finished products destruction to make experimental samples from them. The purpose of this study is the development of a dynamic method that allows operatively determine the diffusion coefficient in finished products from porous materials without destroying them. The method is designed to investigate the solvents diffusion coefficient in building constructions from materials having a porous structure: brick, concrete and aerated concrete, gypsum, cement, gypsum or silicate solutions, gas silicate blocks, heat insulators, etc. A mathematical model of the method is constructed. The influence of the design and measuring device operating parameters on the method accuracy is studied. The application results of the developed method for structural porous products are presented.

  19. Non-destructive local determination of doping additions and main components in single crystals

    International Nuclear Information System (INIS)

    Ehksperiandova, L.P.; Blank, A.B.; Kukhtina, N.N.; Afanasiadi, L.I.

    1994-01-01

    Procedures for local non-destructive determination of elements in optical and scintillation single crystals are developed. They are applied for determination of the main components (in cadmium tungstate) and doping additions (tellurium in zinc selenide, europium in gadolinium silicate). The metrological characteristics of the developed micro-analysis methods are estimated. Segregation of the main components and doping additions in the objects under consideration are investigated. Tellurium is found to be distributed uniformly on the cross-sections of bulk zinc selenide single crystals. The segregation of europium along gadolinium silicate ingots is almost absent. On the cross-section surface of cadmium tungstate single crystals the microregions are found characterized by the prevailing contents of cadmium or tungsten

  20. Determination of plutonium content in TRR spent fuel by nondestructive neutron counting

    International Nuclear Information System (INIS)

    Chen, Y.-F.; Sheu, R.-J.; Chiao, L.-H.; Yuan, M.-C.; Jiang, S.-H.

    2010-01-01

    For the nuclear safeguard purpose, this work aims to nondestructively determine the plutonium content in the Taiwan Research Reactor (TRR) spent fuel rods in the storage pool before the stabilization process, which transforms the metal spent fuel rods into oxide powder. A SPent-fuel-Neutron-Counter (SPNC) system was designed and constructed to carry out underwater scan measurements of neutrons emitting from the spent fuel rod, from which the 240 Pu mass in the fuel rod will be determined. The SAS2 H control module of the SCALE 5.1 code package was applied to calculate the 240 Pu-to-Pu mass ratio in the TRR spent fuel rod according to the given power history. This paper presents the methodology and design of our detector system as well as the measurements of four TRR spent fuel rods in the storage pool and the comparison of the measured results with the facility declared values.

  1. Nondestructive determination of residual fuel on leached hulls and dissolver sludges from LWR fuel reprocessing

    International Nuclear Information System (INIS)

    Wuerz, H.; Wagner, K.; Becker, H.J.

    1990-01-01

    In reprocessing plants leached hulls and dissolver sludges represent rather important intermediate level α-waste streams. A control of the Pu content of these waste streams is desirable. The nondestructive assay method to be preferred would be passive neutron counting. However, before any decision on passive neutron monitoring becomes possible, a characterization of hulls and sludges in terms of Pu content and neutron emission is necessary. For the direct determination of Plutonium on hulls and in sludges, as coming from reprocessing, an active neutron measurement is required. A simple, and sufficiently sensitive active neutron method which can easily be installed uses a stationary 252 Cf neutron source. This method was used for the characterization of hulls and sludges in terms of Plutonium content and total neutron emission in the Karlsruhe reprocessing plant WAK

  2. Determination of nuclear fuel burnup by non-destructive gamma spectroscopy

    International Nuclear Information System (INIS)

    Soares, A.J.

    1979-01-01

    The determination of nuclear fuel burnup by the non-destructive gamma spectroscopy method is studied. A MTR (Materials Testing Reactor) -type fuel element is used in the measurement. The fuel element was removed from the reactor core in 1958 and, because of the long decay time, show only one peak in is gamma spectrum at 661.6 Kev. Corresponding to 137 Cs. Measurements are made at 330 points of the element using a Nal detector and the final result revealed that the quantity of 235 U consumed was 3.3 +- 0,8 milligram in the entire element. The effect of the migration of 137 Cs in the element is neglected in view of the fact that it occurs only when the temperature is above 1000 0 C, which is not the case in IEAR-1. (Author)

  3. Non-destructive determination of trace-element concentrations. Annual progress report, September 1977

    International Nuclear Information System (INIS)

    Gordon, G.E.; Zoller, W.H.; Walters, W.B.

    1977-01-01

    Equipment has been assembled at the National Bureau of Standards (NBS) reactor by the University of Maryland group in cooperation with the NBS staff in order to initiate studies of a new analytical technique, neutron-capture prompt γ-ray activation analysis. According to this technique one observes prompt γ-rays while the sample is under neutron bombardment, rather than observing γ rays from decay of radioactive species produced. It is expected that this technique will make possible the non-destructive determination of a number of elements in several classes of samples that cannot be measured by present analytical methods. A beam thimble has been built for insertion into the reactor. A beam stop and target holder have been designed and are under construction. The detection system has been designed and is on order. The pulse-height analyzer system has been obtained and debugged and most of the software needed has been written

  4. A comparison between destructive and non-destructive techniques in determining coating thickness

    Science.gov (United States)

    Haider, F. I.; Suryanto; Ani, M. H.; Mahmood, M. H.

    2018-01-01

    Measuring coating thickness is an important part in research works related to coating applications. In general, techniques for measuring coating thickness may be divided into destructive and non-destructive methods which are commonly used depending on the applications. The objective of this study is to compare two methods measuring the coating thickness of electroplating copper coating on the austenitic stainless-steel substrate. The electroplating was carried out in a solution containing 200 g/L CuSO4, 100 g/L H2SO4 at room temperature and current of 40mA/cm2 during 20, 40, 60, 80 and 100 mins as coating periods. And the coating thickness was measured by two methods, cross sectional analysis as a destructive technique and weight gain as a non-destructive technique. The results show that at 20 mins coating time interval, the thickness measured by cross sectional method was 16.67 μm and by weight gain method was 17.37 μm, with difference of 0.7 μm and percentage error of 4.11%. This error increased to 5.27% at 100mins time interval, where the values of the thickness measured by cross sectional and weight gain were 86.33 μm and 81.9 μm respectively, and the difference was 4.43 μm. Moreover, though the weight gain method is fast and gives the indication for the termination of a coating process, information regarding the uniformity, porosity and the presence of cracks cannot be obtained. On the other hand, determining the coating thickness using destructive method will damage the sample.

  5. Determination of Flaw Type and Location Using an Expert Module in Ultrasonic Nondestructive Testing for Weld Inspection

    Science.gov (United States)

    Shahriari, D.; Zolfaghari, A.; Masoumi, F.

    2011-01-01

    Nondestructive evaluation is explained as nondestructive testing, nondestructive inspection, and nondestructive examination. It is a desire to determine some characteristic of the object or to determine whether the object contains irregularities, discontinuities, or flaws. Ultrasound based inspection techniques are used extensively throughout industry for detection of flaws in engineering materials. The range and variety of imperfections encountered is large, and critical assessment of location, size, orientation and type is often difficult. In addition, increasing quality requirements of new standards and codes of practice relating to fitness for purpose are placing higher demands on operators. Applying of an expert knowledge-based analysis in ultrasonic examination is a powerful tool that can help assure safety, quality, and reliability; increase productivity; decrease liability; and save money. In this research, an expert module system is coupled with ultrasonic examination (A-Scan Procedure) to determine and evaluate type and location of flaws that embedded during welding parts. The processing module of this expert system is implemented based on EN standard to classify welding defects, acceptance condition and measuring of their location via echo static pattern and image processing. The designed module introduces new system that can automate evaluating of the results of A-scan method according to EN standard. It can simultaneously recognize the number and type of defects, and determine flaw position during each scan.

  6. Characterization of airborne particulate matter in Santiago, Chile. Part 5: non-destructive determination by x-ray fluorescence

    International Nuclear Information System (INIS)

    Poblete, V.H.; Hurtado, O.; Toro, P.

    1995-01-01

    A procedure for non-destructive analysis of airborne particular matter using X ray fluorescence is presented. The elements Fe, Pb and Zn were determined and their concentration compared with the results reported by other techniques. The homogeneity of the distribution of Fe in the samples was investigated. (author). 4 refs, 5 figs

  7. Nondestructive determination of the modulus of elasticity of Fraxinus mandschurica using near-infrared spectroscopy

    Science.gov (United States)

    Yu, Huiling; Liang, Hao; Lin, Xue; Zhang, Yizhuo

    2018-04-01

    A nondestructive methodology is proposed to determine the modulus of elasticity (MOE) of Fraxinus mandschurica samples by using near-infrared (NIR) spectroscopy. The test data consisted of 150 NIR absorption spectra of the wood samples obtained using an NIR spectrometer, with the wavelength range of 900 to 1900 nm. To eliminate the high-frequency noise and the systematic variations on the baseline, Savitzky-Golay convolution combined with standard normal variate and detrending transformation was applied as data pretreated methods. The uninformative variable elimination (UVE), improved by the evolutionary Monte Carlo (EMC) algorithm and successive projections algorithm (SPA) selected three characteristic variables from full 117 variables. The predictive ability of the models was evaluated concerning the root-mean-square error of prediction (RMSEP) and coefficient of determination (Rp2) in the prediction set. In comparison with the predicted results of all the models established in the experiments, UVE-EMC-SPA-LS-SVM presented the best results with the smallest RMSEP of 0.652 and the highest Rp2 of 0.887. Thus, it is feasible to determine the MOE of F. mandschurica using NIR spectroscopy accurately.

  8. An integrated approach for determining plutonium mass in spent fuel assemblies with nondestructive assay

    International Nuclear Information System (INIS)

    Swinhoe, Martyn T.; Tobin, Stephen J.; Fensin, Mike L.; Menlove, Howard O.

    2009-01-01

    There are a variety of reasons for quantifying plutonium (Pu) in spent fuel. Below, five motivations are listed: (1) To verify the Pu content of spent fuel without depending on unverified information from the facility, as requested by the IAEA ('independent verification'). New spent fuel measurement techniques have the potential to allow the IAEA to recover continuity of knowledge and to better detect diversion. (2) To assure regulators that all of the nuclear material of interest leaving a nuclear facility actually arrives at another nuclear facility ('shipper/receiver'). Given the large stockpile of nuclear fuel at reactor sites around the world, it is clear that in the coming decades, spent fuel will need to be moved to either reprocessing facilities or storage sites. Safeguarding this transportation is of significant interest. (3) To quantify the Pu in spent fuel that is not considered 'self-protecting.' Fuel is considered self-protecting by some regulatory bodies when the dose that the fuel emits is above a given level. If the fuel is not self-protecting, then the Pu content of the fuel needs to be determined and the Pu mass recorded in the facility's accounting system. This subject area is of particular interest to facilities that have research-reactor spent fuel or old light-water reactor (LWR) fuel. It is also of interest to regulators considering changing the level at which fuel is considered self-protecting. (4) To determine the input accountability value at an electrochemical processing facility. It is not expected that an electrochemical reprocessing facility will have an input accountability tank, as is typical in an aqueous reprocessing facility. As such, one possible means of determining the input accountability value is to measure the Pu content in the spent fuel that arrives at the facility. (5) To fully understand the composition of the fuel in order to efficiently and safely pack spent fuel into a long-term repository. The NDA of spent fuel can

  9. Nondestructive and in situ determination of graphene layers using optical fiber Fabry–Perot interference

    International Nuclear Information System (INIS)

    Li, Cheng; Peng, Xiaobin; Liu, Qianwen; Fan, Shangchun; Gan, Xin; Lv, Ruitao

    2017-01-01

    Thickness measurement plays an important role for characterizing optomechanical behaviors of graphene. From the view of graphene-based Fabry–Perot (F–P) sensors, a simple, nondestructive and in situ method of determining the thickness of nanothick graphene membranes was demonstrated by using optical fiber F–P interference. Few-layer/multilayer graphene sheets were suspendedly adhered onto the endface of a ferrule with a 125 µ m inner diameter by van der Waals interactions to construct micro F–P cavities. Along with the Fresnel’s law and complex index of refraction of the membrane working as a light reflector of an F–P interferometer, the optical reflectivity of graphene was modeled to investigate the effects of light wavelength and temperature. Then the average thickness of graphene membranes were extracted by F–P interference demodulation, and yielded a very strong cross-correlation coefficient of 99.95% with the experimental results observed by Raman spectrum and atomic force microscope. The method could be further extended for determining the number of layers of other 2D materials. (paper)

  10. Determination of the radionuclide release factor for an evaporator process using nondestructive assay

    International Nuclear Information System (INIS)

    Johnson, R.E.

    1998-01-01

    The 242-A Evaporator is the primary waste evaporator for the Hanford Site radioactive liquid waste stored in underground double-shell tanks. Low pressure evaporation is used to remove water from the waste, thus reducing the amount of tank space required for storage. The process produces a concentrated slurry, a process condensate, and an offgas. The offgas exhausts through two stages of high-efficiency particulate air (HEPA) filters before being discharged to the atmosphere 40 CFR 61 Subpart H requires assessment of the unfiltered exhaust to determine if continuous compliant sampling is required. Because potential (unfiltered) emissions are not measured, methods have been developed to estimate these emissions. One of the methods accepted by the Environmental Protection Agency is the measurement of the accumulation of radionuclides on the HEPA filters. Nondestructive assay (NDA) was selected for determining the accumulation on the HEPA filters. NDA was performed on the HEPA filters before and after a campaign in 1997. NDA results indicate that 2.1 E+4 becquerels of cesium-137 were accumulated on the primary HEPA 1700 filter during the campaign. The feed material processed in the campaign contained a total of 1.4 E+l6 Bq of cesium-137. The release factor for the evaporator process is 1.5 E-12. Based on this release factor, continuous compliant sampling is not required

  11. Dose-rate determination by radiochemical analysis

    International Nuclear Information System (INIS)

    Mangini, A.; Pernicka, E.; Wagner, G.A.

    1983-01-01

    At the previous TL Specialist Seminr we had suggested that α-counting is an unsuitable technique for dose-rate determination due to overcounting effects. This is confirmed by combining α-counting, neutron activation analysis, fission track counting, α-spectrometry on various pottery samples. One result of this study is that disequilibrium in the uranium decay chain alone cannot account for the observed discrepancies between α-counting and chemical analysis. Therefore we propose for routine dose-rate determination in TL dating to apply chemical analysis of the radioactive elements supplemented by an α-spectrometric equilibrium check. (author)

  12. Nondestructive determination of residual fuel on leached hulls and dissolver sludges from LWR fuel reprocessing

    International Nuclear Information System (INIS)

    Wuerz, H.; Wagner, K.; Becker, H.J.

    1990-01-01

    In reprocessing plants leached hulls and dissolver sludges represent rather important intermediate level α-waste streams. A control of the Pu content of these waste streams is desirable. The nondestructive assay method to be preferred would be passive neutron counting. However, before any decision on passive neutron monitoring becomes possible a characterization of hulls and sludges in terms of Pu content and neutron emission is necessary. For the direct determination of plutonium on hulls and in sludges, as coming from reprocessing, an active neutron measurement is required. A simple, and sufficiently sensitive active neutron method which can easily be installed uses as stationary Cf-252 neutron source. This method was used for the characterization of hulls and sludges in terms of plutonium content and total neutron emission in the WAK. Meanwhile a total of 28 batches of leached hulls and 22 batches of dissolver sludges from reprocessing of PWR fuel have been assayed. The paper describes the assay method used and gives an analysis of the error sources together with a discussion of the results and the accuracies obtained in a reprocessing plant. (orig./HP)

  13. Determination of sterilizing dose of lincocine drug

    International Nuclear Information System (INIS)

    Adawi, M.A.; Shamma, M.; Al-Mousa, A.

    1998-01-01

    There are too many antibiotics that have been studied on their dry solid state to determine their safe sterilizing dose by decreasing their bio burden in order to reach the sterility assurance level (SAL) needed. The sterilizing radiating dose of lincocine was determined according to information about their bio burden and radiating sensitivity at the sterility assurance level 10-6. The study of bio burden has shown that the contamination was fungal (Pemicillium sp.) and by applying the same tests to the raw materials of lincocine it came out that the cause of contamination was bad storage and that the radiating dose required to decrease the bio burden was 5.5 kGy. (author)

  14. Specific features of the determination of the pellet-cladding gap of the fuel rods by non-destructive method

    International Nuclear Information System (INIS)

    Amosov, S.V.; Pavlov, S.V.

    2002-01-01

    This report describes the specific features of determining the pellet-cladding gap of the irradiated WWER-1000 fuel rods by nondestructive method. The method is based on the elastic radial deformation of the cladding up to its contact with the fuel. The value of deformation of cladding till its contacting fuel when radial force changes from F max to 0 is proposed as a measuring parameter for determination of the diametrical gap. Because of the features of compression method, the obtained gap value is not analog of the gap measured on micrograph of the fuel rod cross-section. Results of metallography can provide only qualitative evaluation of its method efficiency. Comparison of the values determined by non-destructive method and metallography for WWER-1000 fuel rods with burnup from 25 to 55 MWd/kg U testified that the results of compression method can be used as a low estimate of the pellet-cladding gap value. (author)

  15. Dose determination on buildup region using photodiodes

    International Nuclear Information System (INIS)

    Khoury, H.J.; Lopes, F.J.; Melo, F. de A.

    1989-01-01

    A clinical dosemeter using photodiode BPW-34 was developed, allowing the determination of dose on buildup region. The measures were made with X-rays beam of linear accelerator and with gamma radiation of cobalt 60. The results were compared with others made in a ionization chamber. (C.G.C.) [pt

  16. An accurate method for determining residual stresses with magnetic non-destructive techniques in welded ferromagnetic steels

    International Nuclear Information System (INIS)

    Vourna, P

    2016-01-01

    The scope of the present research work was to investigate the proper selection criteria for developing a suitable methodology for the accurate determination of residual stresses existing in welded parts. Magnetic non-destructive testing took place by the use of two magnetic non-destructive techniques: by the measurement of the magnetic Barkhausen noise and by the evaluation of the magnetic hysteresis loop parameters. The spatial distribution of residual stresses in welded metal parts by both non-destructive magnetic methods and two diffraction methods was determined. The conduction of magnetic measurements required an initial calibration of ferromagnetic steels. Based on the examined volume of the sample, all methods used were divided into two large categories: the first one was related to the determination of surface residual stress, whereas the second one was related to bulk residual stress determination. The first category included the magnetic Barkhausen noise and the X-ray diffraction measurements, while the second one included the magnetic permeability and the neutron diffraction data. The residual stresses determined by the magnetic techniques were in a good agreement with the diffraction ones. (paper)

  17. Determination of environmental radioactivity for dose assessment

    International Nuclear Information System (INIS)

    Nakoaka, A.; Fukushima, M.; Takagi, S.

    1980-01-01

    A method was devised to determine detection limits for radioactivity in environmental samples. The method is based on the 5 mrem/yr whole-body dose objective established by the Japan Atomic Enerty Commission and is valid for assessing the internal dose from radionuclides in the environment around a nuclear facility. Eleven samples and 15 radionuclides were considered. Internal dose was assumed to be one-half of the total dose (5 mrem/yr) and was assessed using the critical pathway method. Needed detection limits (NDLs) were established to confirm the dose of 5 mrem/yr when there was more than one radionuclide per sample. The NDLs for γ-emitters were 10 -5 pCi/l. for air; 10 -3 pCi/l. for seawater; 10 -1 pCi/l. for drinking water; 10 0 pCi/kg for vegetables and fish; 10 0 pCi/l. for milk; and 10 1 pCi/kg for molluscs, crustaceans, seaweeds, soil and submarine sediments. The NDLs for β-emitters were 1-1/100 of those for γ-emitters. (author)

  18. Nondestructive Determination of Cu Residue in Orange Peel by Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Hu Huiqin; Huang Lin; Liu Muhua; Chen Tianbing; Yang Ping; Yao Mingyin

    2015-01-01

    Laser induced breakdown spectroscopy (LIBS) is an emerging tool with rapid, nondestructive, green characteristics in qualitative or quantitative analyses of composition in materials. But LIBS has its shortcomings in detect limit and sensitivity. In this work, heavy metal Cu in Gannan Navel Orange, which is one of famous fruits from Jiangxi of China, was analyzed. In view of LIBS's limit, it is difficult to determinate heavy metals in natural fruits. In this work, nine orange samples were pretreated in 50-500 μg/mL Cu solution, respectively. Another one orange sample was chosen as a control group without any pollution treatment. Previous researchers observed that the content of heavy metals is much higher in peel than in pulp. So, the content in pulp can be reflected by detecting peel. The real concentrations of Cu in peels were acquired by atomic absorption spectrophotometer (AAS). A calibration model of Cu I 324.7 and Cu I 327.4 was constructed between LIBS intensity and AAS concentration by six samples. The correlation coefficient of the two models is also 0.95. All of the samples were used to verify the accuracy of the model. The results show that the relative error (RE) between predicted and real concentration is less than 6.5%, and Cu I 324.7 line has smaller RE than Cu I 327.4. The analysis demonstrated that different characteristic lines decided different accuracy. The results prove the feasibility of detecting heavy metals in fruits by LIBS. But the results are limited in treated samples. The next work will focus on direct analysis of heavy metals in natural fruits without any pretreatment. This work is helpful to explore the distribution of heavy metals between pulp and peel. (paper)

  19. Nondestructive Determination of Cu Residue in Orange Peel by Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Hu, Huiqin; Huang, Lin; Liu, Muhua; Chen, Tianbing; Yang, Ping; Yao, Mingyin

    2015-08-01

    Laser induced breakdown spectroscopy (LIBS) is an emerging tool with rapid, nondestructive, green characteristics in qualitative or quantitative analyses of composition in materials. But LIBS has its shortcomings in detect limit and sensitivity. In this work, heavy metal Cu in Gannan Navel Orange, which is one of famous fruits from Jiangxi of China, was analyzed. In view of LIBS's limit, it is difficult to determinate heavy metals in natural fruits. In this work, nine orange samples were pretreated in 50-500 μg/mL Cu solution, respectively. Another one orange sample was chosen as a control group without any pollution treatment. Previous researchers observed that the content of heavy metals is much higher in peel than in pulp. So, the content in pulp can be reflected by detecting peel. The real concentrations of Cu in peels were acquired by atomic absorption spectrophotometer (AAS). A calibration model of Cu I 324.7 and Cu I 327.4 was constructed between LIBS intensity and AAS concentration by six samples. The correlation coefficient of the two models is also 0.95. All of the samples were used to verify the accuracy of the model. The results show that the relative error (RE) between predicted and real concentration is less than 6.5%, and Cu I 324.7 line has smaller RE than Cu I 327.4. The analysis demonstrated that different characteristic lines decided different accuracy. The results prove the feasibility of detecting heavy metals in fruits by LIBS. But the results are limited in treated samples. The next work will focus on direct analysis of heavy metals in natural fruits without any pretreatment. This work is helpful to explore the distribution of heavy metals between pulp and peel. supported by National Natural Science Foundation of China (No. 31460419) and Major Project of Science and Technology of Jiangxi, China (No. 20143ACB21013)

  20. On determining dose rate constants spectroscopically

    International Nuclear Information System (INIS)

    Rodriguez, M.; Rogers, D. W. O.

    2013-01-01

    Purpose: To investigate several aspects of the Chen and Nath spectroscopic method of determining the dose rate constants of 125 I and 103 Pd seeds [Z. Chen and R. Nath, Phys. Med. Biol. 55, 6089–6104 (2010)] including the accuracy of using a line or dual-point source approximation as done in their method, and the accuracy of ignoring the effects of the scattered photons in the spectra. Additionally, the authors investigate the accuracy of the literature's many different spectra for bare, i.e., unencapsulated 125 I and 103 Pd sources. Methods: Spectra generated by 14 125 I and 6 103 Pd seeds were calculated in vacuo at 10 cm from the source in a 2.7 × 2.7 × 0.05 cm 3 voxel using the EGSnrc BrachyDose Monte Carlo code. Calculated spectra used the initial photon spectra recommended by AAPM's TG-43U1 and NCRP (National Council of Radiation Protection and Measurements) Report 58 for the 125 I seeds, or TG-43U1 and NNDC(2000) (National Nuclear Data Center, 2000) for 103 Pd seeds. The emitted spectra were treated as coming from a line or dual-point source in a Monte Carlo simulation to calculate the dose rate constant. The TG-43U1 definition of the dose rate constant was used. These calculations were performed using the full spectrum including scattered photons or using only the main peaks in the spectrum as done experimentally. Statistical uncertainties on the air kerma/history and the dose rate/history were ⩽0.2%. The dose rate constants were also calculated using Monte Carlo simulations of the full seed model. Results: The ratio of the intensity of the 31 keV line relative to that of the main peak in 125 I spectra is, on average, 6.8% higher when calculated with the NCRP Report 58 initial spectrum vs that calculated with TG-43U1 initial spectrum. The 103 Pd spectra exhibit an average 6.2% decrease in the 22.9 keV line relative to the main peak when calculated with the TG-43U1 rather than the NNDC(2000) initial spectrum. The measured values from three different

  1. Nondestructive Testing

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Harold [Argonne National Laboratory

    1969-01-01

    A nondestructive test is an examination of an object in any manner which will not impair the future usefulness of the object. This booklet discusses a few basic methods of nondestructive testing, and some of their characteristics. In addition, it discusses possible future methods for nondestructive testing by taking a quick look at some of the methods now under study.

  2. Non-destructive automated express method for determining the inclination of chromium-nickel steels IGC

    International Nuclear Information System (INIS)

    Nazarov, A.A.; Kamenev, Yu.B.; Kuusk, L.V.; Kormin, E.G.; Vasil'ev, A.N.; Sumbaeva, T.E.

    1986-01-01

    Methods of automated control of 18-10-type steel inclination to IGC are developed and a corresponding automated testing complex (ATS) is created. 08Kh18N10T steel samples had two variants of thermal treatment: 1) 1200 deg (5 h), 600 deg (50 h); 2) 1200 deg (5 h). Methods of non-destructive automated control of 18-10-type steel inclination to IGC are developed on the basis of potentiodynamic reactivation (PR) principle. Automated testing complex is developed, which has undergone experimental running and demonstrated a high confidence of results, reliability and easy operation

  3. Determination of absorbed dose in reactors

    International Nuclear Information System (INIS)

    1971-01-01

    There are many areas in the use and operation of research reactors where the absorbed dose and the neutron fluence are required. These include work on the determination of the radiolytic stability of the coolant and moderator and on the determination of radiation damage in structural materials, and reactor experiments involving radiation chemistry and radiation biology. The requirements range from rough estimates of the total heating due to radiation to precise values specifying the contributions of gamma rays, thermal neutrons and fast neutrons. To meet all these requirements a variety of experimental measurements and calculations as well as a knowledge of reactor radiations and their interactions is necessary. Realizing the complexity and importance of this field, its development at widely separated laboratories and the need to bring the experts in this work together, the IAEA has convened three panel meetings. These were: 'In-pile dosimetry', held in July 1964 (published by the Agency as Technical Reports Series No. 46); 'Neutron fluence measurements', in October 1965; and 'In-pile dosimetry', in November 1966. The recommendations of these three panels led the Agency to form a Working Group on Reactor Radiation Measurements and to commission the writing of this book and a book on Neutron Fluence Measurements. The latter was published in May 1970 (Technical Reports Series No. 107). The material on neutron fluence and absorbed dose measurements is widely scattered in reports and reviews. It was considered that it was time for all relevant information to be evaluated and put together in the form of a practical guide that would be valuable both to experienced workers and beginners in the field

  4. Nanogram determination of arsenic in biological reference materials by non-destructive Compton suppression neutron activation analysis

    International Nuclear Information System (INIS)

    Petra, M.; Landsberger, S.; Swift, G.

    1990-01-01

    Non-destructive epithermal neutron activation analysis in conjunction with Compton suppression has been applied to determine arsenic in seven biological standard reference materials from the National Institute of Standards and Technology. The accuracy is in excellent agreement with all the certified values and compilation results. For four of the materials detection limits between 1-4 ng/g were easily achieved while for three others they ranged from 18-50 ng/g. Overall analytical precision typically varied between 2-4% for five of the reference materials while for two other it was between 12-16%. These methods clearly demonstrate that through a judicious approach of anti-coincidence techniques, nanogram quantities of arsenic can be reliably determined without the need for labor intensive chemical separations. (orig.)

  5. Determination of Na, Mn and Cu in cocoon, raw silk and degummed silk by nondestructive activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Maki, Y; Ishiguro, Y [Industrial Research Inst. of Kanagawa Prefecture, Yokohama (Japan)

    1976-01-01

    The sodium, manganese and copper contained in cocoons, raw silk and degummed silk thread were determined by the nondestructive activation analysis. After each sample was irradiated with the thermal neutron flux of 5 x 10/sup 11/n/cm/sup 2/.sec, its ..gamma..-ray spectrum was measured with a NaI(Tl) detector. With the photoelectric peaks at 511 keV (/sup 64/Cu), 1368 keV (/sup 24/Na) and 847 keV (/sup 56/Mn), each element was quantitatively determined and its content was obtained. The measurement of the ..gamma..-ray spectra of samples with a Ge (Li) detector proved the presence of An, Sb, Fe, Zn, Cr, Sc, Co, etc. Large amounts of Na and Cu were detected in the sericin portion of cocoons, and the adhesion of Cu from a reeling-off machine to raw silk was also observed during the process of degumming cocoons to make raw silk.

  6. Nondestructive determination of uranium-235 enrichment in gas ultracentrifugation enrichment plants

    International Nuclear Information System (INIS)

    Lauppe, W.D.; Richter, B.; Stein, G.

    1990-02-01

    Based on similar studies in the USA and the UK, two γ spectroscopic techniques were propagated by the IAEA, after they had been sucesssfully tried at Capenhurst (GB) centrifuge plant. It was assumed by the IAEA that these methods would be transferable to the Almelo and Gronau plants, even without knowledge of the specific plant parameters there. The scope of this research project covered the study and further development of the proposed γ-spectroscopic measuring methods for applicability in the GUC plant in Gronau. The research came within the terms of reference of Task C.14.7 of the IAEA and BMFT (German Federal Ministry of Research and Technology)'s joint research and development programme. When the funded project first started, the Gronau plant was not yet on stream. The initial measurements were therefore, taken in Almelo, where conditions were similar to those in Gronau. The report describes the underlying problems which occur in relation to the non-destructive measuring of 235 U enrichment under the specific boundary conditions in Almelo and Gronau. The results illustrate the limitations of application of the measuring techniques, even after adjustment to actual conditions in Almelo and Gronau. It is not always possible to obtain a reliable yes/no answer in favour of slightly enriched uranium, particularly in product lines with extreme boundary conditions, irrespective of the technique applied. (orig.) [de

  7. Determining organ dose: the holy grail

    International Nuclear Information System (INIS)

    Samei, Ehsan; Tian, Xiaoyu; Segars, W.P.

    2014-01-01

    Among the various metrics to quantify CT radiation dose, organ dose is generally regarded as one of the best to reflect patient radiation burden. Organ dose is dependent on two main factors, namely patient anatomy and irradiation field. An accurate estimation of organ dose requires detailed modeling of both factors. The modeling of patient anatomy needs to reflect the anatomical diversity and complexity across the population so that the attributes of a given clinical patient can be properly accounted for. The modeling of the irradiation field needs to accurately reflect the CT system condition, especially the tube current modulation (TCM) technique. We present an atlas-based method to model patient anatomy via a library of computational phantoms with representative ages, sizes and genders. A clinical patient is matched with a corresponding computational phantom to obtain a representation of patient anatomy. The irradiation field of the CT system is modeled using a validated Monte Carlo simulation program. The tube current modulation profiles are simulated using a manufacturer-generalizable ray-tracing algorithm. Combining the patient model, Monte Carlo results, and TCM profile, organ doses are obtained by multiplying organ dose values from a fixed mA scan (normalized to CTDI vol -normalized, denoted as h organ ) and an adjustment factor that reflects the specific irradiation of each organ. The accuracy of the proposed method was quantified by simulating clinical abdominopelvic examinations of 58 patients. The predicted organ doses showed good agreement with simulated organ dose across all organs and modulation schemes. For an average CTDI vol of a CT exam of 10 mGy, the absolute median error across all organs was 0.64 mGy (-0.21 and 0.97 for 25th and 75th percentiles, respectively). The percentage differences were within 15%. The study demonstrates that it is feasible to estimate organ doses in clinical CT examinations for protocols without and with tube current

  8. Non-destructive determination of photosynthetic rates of eight varieties of cassava (Manihot esculenta Crantz)

    International Nuclear Information System (INIS)

    Amadu, A. A.

    2015-07-01

    Cassava is an important food security crop in Ghana and in the wake of climate change there is the need for plant breeders to develop varieties with high water use efficiency as well as high photosynthetic rate in order to adapt to the changing climate. Thus, the photosynthetic rates of eight cassava (Manihot esculenta Crantz) varieties were non-destructively evaluated using photosynthesis meter miniPPM300, from June 2014 to May 2015, with the aim of selecting varieties with high photosynthetic rate for future breeding programmes. The mean photosynthetic rate varied depending on the varieties ranging from 40.5 μmol/m 2 s in Bosom nsia to 45.2 μmol/m 2 s in Gbenze. However, the presence of African cassava mosaic disease (ACMD) marginally reduced the photosynthetic rate to below 40 μmol/m 2 s in all the varieties. Similarly, the chlorophyll content index (CCI) as measured by chlorophyll meter and spectrophotometer also varied from one variety to another; it was low in Nandom (17.9 CCI) and high in Gbenze (39.93 CCI) using the chlorophyll meter and was also reduced by the presence of the virus. Although, the stomatal density varied between the varieties it was not influenced by virus infection. Furthermore, ACMD significantly decreased the leaf surface area from 5705.8mm 2 in uninfected plants to 1251.6mm 2 in infected plants, consequently reducing the number and weight of tubers produced 11 month after planting (MAP). Molecular Testing of the viruses using virus specific primers JSP001/JSP002, EAB555F/EAB555R, EACMV1e/EACMV2e at 6 MAP and 11MAP, showed that the mosaic symptoms were caused by African Cassava Mosaic virus disease. Cassava varieties with high photosynthetic efficiency and low virus infection can be used in cassava improvement programmes in Ghana. (au)

  9. Simple Linear Regression and Reflectance Sensitivity Analysis Used to Determine the Optimum Wavelength for Nondestructive Assessment of Chlorophyll in Fresh Leaves Using Spectral Reflectance

    Science.gov (United States)

    The accuracy of nondestructive optical methods for chlorophyll (Chl) assessment based on leaf spectral characteristics depends on the wavelengths used for Chl assessment. Using spectroscopy, the optimum wavelengths for Chl assessment (OWChl) were determined for almond, poplar, and apple trees grown ...

  10. Opto-thermal transient emission radiometry for rapid, non-destructive and non-contact determination of hydration and hydration depth profile in the skin of a grape

    NARCIS (Netherlands)

    Guo, X.; Bicanic, D.D.; Keijser, K.; Imhof, R.

    2003-01-01

    .The concept of optothermal transient emission radiometry at a wavelength of 2.94 µm was applied to non-destructively determine the level of hydration and the profile of hydration in the skin of intact fresh grapes taken from top and bottom sections of the same bunch.

  11. A practical approach to determine dose metrics for nanomaterials.

    Science.gov (United States)

    Delmaar, Christiaan J E; Peijnenburg, Willie J G M; Oomen, Agnes G; Chen, Jingwen; de Jong, Wim H; Sips, Adriënne J A M; Wang, Zhuang; Park, Margriet V D Z

    2015-05-01

    Traditionally, administered mass is used to describe doses of conventional chemical substances in toxicity studies. For deriving toxic doses of nanomaterials, mass and chemical composition alone may not adequately describe the dose, because particles with the same chemical composition can have completely different toxic mass doses depending on properties such as particle size. Other dose metrics such as particle number, volume, or surface area have been suggested, but consensus is lacking. The discussion regarding the most adequate dose metric for nanomaterials clearly needs a systematic, unbiased approach to determine the most appropriate dose metric for nanomaterials. In the present study, the authors propose such an approach and apply it to results from in vitro and in vivo experiments with silver and silica nanomaterials. The proposed approach is shown to provide a convenient tool to systematically investigate and interpret dose metrics of nanomaterials. Recommendations for study designs aimed at investigating dose metrics are provided. © 2015 SETAC.

  12. Rapid determination of fluorine in coral skeletons by non-destructive neutron activation analysis using 20F

    International Nuclear Information System (INIS)

    Ramos, A.A.; Ohde, S.; Sirirattanachai, S.; Snidvongs, A.

    2003-01-01

    A rapid non-destructive technique has been proposed for the determination of fluorine in coral skeletons by thermal neutron activation analysis, using the short half-life 20 F nuclide (11.0 s). About 0.2-0.5 g samples were irradiated for 10 seconds in a Triga Mark II Reactor. Soon after the irradiation (25-35 s), measurements of γ-rays were performed with each sample and standard. The method has the drawback of low sensitivity (∼20 ppm of F), and the manual operation employed in the cooling step could lead to less precise measurements. Fluorine in coral standards was determined within ∼8% of analytical precision. The result obtained for the dolomite standard was fairly consistent with literature values, but those for the limestone standard showed to be considerably higher than the reported values. The present method was applied for the determination of fluorine in modern corals from Khang Khao Island, Thailand and Okinawa, Japan. Two core samples of an ancient reef from Funafuti Atoll were measured for fluorine to compare with modern samples. In order to understand the environmental media in which coral grew, the partition of fluorine between seawater and coral skeletons is also discussed. (author)

  13. Determination of effective dose of antimalarial from Cassia ...

    African Journals Online (AJOL)

    However, further investigation is required to determine an effective dose of the administered extract for a higher inhibitory effect and increasing effectiveness of the extract. Material and Methods: To determine the effective dose of ethanol extract of C. spectabilis leaves, a "4-day suppressive test"of Peter was performed with ...

  14. Uranium and thorium loadings determined by chemical and nondestructive methods in HTGR fuel rods for the Fort St. Vrain Early Validation Irradiation Experiment

    International Nuclear Information System (INIS)

    Angelini, P.; Rushton, J.E.

    1979-01-01

    The Fort St. Vrain Early Validation Irradiation Experiment is an irradiation test of reference and of improved High-Temperature Gas-Cooled Reactor fuels in the Fort St. Vrain Reactor. The irradiation test includes fuel rods fabricated at ORNL on an engineering scale fuel rod molding machine. Fuel rods were nondestructively assayed for 235 U content by a technique based on the detection of prompt-fission neutrons induced by thermal-neutron interrogation and were later chemically assayed by using the modified Davies Gray potentiometric titration method. The chemical analysis of the thorium content was determined by a volumetric titration method. The chemical assay method for uranium was evaluated and the results from the as-molded fuel rods agree with those from: (1) large samples of Triso-coated fissile particles, (2) physical mixtures of the three particle types, and (3) standard solutions to within 0.05%. Standard fuel rods were fabricated in order to evaluate and calibrate the nondestructive assay device. The agreement of the results from calibration methods was within 0.6%. The precision of the nondestructive assay device was established as approximately 0.6% by repeated measurements of standard rods. The precision was comparable to that estimated by Poisson statistics. A relative difference of 0.77 to 1.5% was found between the nondestructive and chemical determinations on the reactor grade fuel rods

  15. Determination of Absorbed Dose in Large 60-Co Fields Radiotherapy

    International Nuclear Information System (INIS)

    Hrsak, H.

    2003-01-01

    Radiation in radiotherapy has selective impact on ill and healthy tissue. During the therapy the healthy tissue receives certain amount of dose. Therefore dose calculations in outer radiotherapy must be accurate because too high doses produce damage in healthy tissue and too low doses cannot ensure efficient treatment of cancer cells. A requirement on accuracy in the dose calculations has lead to improvement of detectors, and development of absolute and relative dosimetry. Determination of the dose distribution with use of computer is based on data provided by the relative dosimetry. This paper compares the percentage depth doses in cubic water phantoms of various dimensions with percentage depth doses calculated with use of Mayneord factor from the experimental depth doses measured in water phantom of large dimension. Depth doses in water phantoms were calculated by the model of empirical dosimetrical functions. The calculations were based on the assumption that large 6 0C o photon field exceeds the phantom's limits. The experimental basis for dose calculations by the model of empirical dosimetrical functions were exposure doses measured in air and dose reduction factors because of finite phantom dimensions. Calculations were performed by fortran 90 software. It was found that the deviation of dosimetric model was small in comparison to the experimental data. (author)

  16. Determining Plutonium Mass in Spent Fuel with Nondestructive Assay Techniques -- Preliminary Modeling Results Emphasizing Integration among Techniques

    International Nuclear Information System (INIS)

    Tobin, S.J.; Fensin, M.L.; Ludewigt, B.A.; Menlove, H.O.; Quiter, B.J.; Sandoval, N.P.; Swinhoe, M.T.; Thompson, S.J.

    2009-01-01

    There are a variety of motivations for quantifying Pu in spent (used) fuel assemblies by means of nondestructive assay (NDA) including the following: strengthen the capabilities of the International Atomic Energy Agencies to safeguards nuclear facilities, quantifying shipper/receiver difference, determining the input accountability value at reprocessing facilities and providing quantitative input to burnup credit determination for repositories. For the purpose of determining the Pu mass in spent fuel assemblies, twelve NDA techniques were identified that provide information about the composition of an assembly. A key point motivating the present research path is the realization that none of these techniques, in isolation, is capable of both (1) quantifying the elemental Pu mass of an assembly and (2) detecting the diversion of a significant number of pins. As such, the focus of this work is determining how to best integrate 2 or 3 techniques into a system that can quantify elemental Pu and to assess how well this system can detect material diversion. Furthermore, it is important economically to down-select among the various techniques before advancing to the experimental phase. In order to achieve this dual goal of integration and down-selection, a Monte Carlo library of PWR assemblies was created and is described in another paper at Global 2009 (Fensin et al.). The research presented here emphasizes integration among techniques. An overview of a five year research plan starting in 2009 is given. Preliminary modeling results for the Monte Carlo assembly library are presented for 3 NDA techniques: Delayed Neutrons, Differential Die-Away, and Nuclear Resonance Fluorescence. As part of the focus on integration, the concept of 'Pu isotopic correlation' is discussed and the role of cooling time determination.

  17. Non-destructive determination of trace-element concentrations. Annual progress report, August 1979

    International Nuclear Information System (INIS)

    Gordon, G.E.; Zoller, W.H.; Walters, W.B.

    1979-08-01

    Development and testing of the neutron-capture prompt γ-ray activation analysis method continued. A wide range of NBS Standard Reference Materials, USGS Standard Rocks, and other materials have been analyzed in order to identify elements whose lines can be observed, to determine interferences and detection limits for each important γ ray of observable elements and to measure concentrations of observable elements for comparison with certified or other previous results. In most crustal samples, concentrations of 16 to 20 elements can be determined

  18. A critical analysis of methods for rapid and nondestructive determination of wood density in standing trees

    Science.gov (United States)

    Shan Gao; Xiping Wang; Michael C. Wiemann; Brian K. Brashaw; Robert J. Ross; Lihai Wang

    2017-01-01

    Key message Field methods for rapid determination of wood density in trees have evolved from increment borer, torsiometer, Pilodyn, and nail withdrawal into sophisticated electronic tools of resistance drilling measurement. A partial resistance drilling approach coupled with knowledge of internal tree density distribution may...

  19. Nondestructive determination of the load bearing capacity of rigid pavement structures. Zerstoerungsfreie Tragfaehigkeitsbestimmung fuer starre Deckenkonstruktionen

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, U. (Bauakademie, IHLGB, Berlin (Germany))

    1991-01-01

    Actual parameters of the bearing capacity of traffic areas are in case of intensive use an indispensable necessity for the determination of the remaining use value with the aim to optimize reinforcing layers and reconstruction periods. Until now there is only one adequate measuring method for flexible layers. With the Rollig load test (RLT) initial data can be gained for the calculation of the load bearing capacity of rigid pavement structures. The method is described with the example of an airplane runway. (BWI).

  20. Determination of barium content in ground water by nondestructive neutron activation method

    International Nuclear Information System (INIS)

    Abdullaev, A.A.; Kutbedinov, A.; Khakhimov, S.; Zakhidov, A.Sh.

    1981-01-01

    The technique for instrumental neutron activation determination of barium microquantities in ground waters is described. The water sample (0.3-0.5 l) is evaporated in sand bath at approximately 95 deg C, dry residual is packed in silver foil, it is soldered with standards in a quartz ampule and irradiated during 20 hours in 1.10 13 n/cm 2 xs thermal neutron flux and it is hold during 10-15 days for decay of interfering radioisotopes Na 24 , K 42 , Cl 38 . Then the sample is repacked and B 133 and Ba 131 activities are measured (Tsub(1/2)=10.7 years and 11.5 days respectively) according to 356 and 496 keV gamma-peaks respectively by means of gamma spectrometer with 60-cm 3 Ge(Li)-detector. The sensitivity of barium determination is nx10 - 9 g/ml, relative mean-square error is 10-18%. The efficiency of the method constitutes 20-25 samples per 6-hour working day in calculation for one analyst without account of radiation interval and holding after radiation

  1. Wide-range neutron dose determination with CR-39

    International Nuclear Information System (INIS)

    Arneja, A.R.; Waker, A.J.

    1995-01-01

    Optical density measurements of CR-30 irradiated with 252 Cf neutrons and chemically etched with 6.5 N KOH solution have been used to determine neutron absorbed doses between 0.1 and 10 Gy. Optimum etching conditions will depend upon the absorbed dose. Since it is not always possible to know the range of absorbed dose on a CR-39 dosemeter collected from personnel and area monitor stations in a criticality accident situation, a three-step two-hour chemical etch at 60 o C has been found to be appropriate. If after a total of six hours of chemical etching the optical density is found to be below 0.04 for 500 nm light (transmission > 90%) then further treatment in the form of electrochemical etching can be carried out to determine the lower absorbed dose. In this manner, absorbed doses below 0.1 Gy can be determined by counting tracks over a unit area. (author)

  2. Non-destructive test method of determination of surface defects in objects

    International Nuclear Information System (INIS)

    Gibbons, C.B.; Sewell, M.H.; Taber, R.C.

    1975-01-01

    In the radiographic method, adsorbed radioactive gas, e.g. krypton 85, is used to determine surface defects such as failures, cracks, and breaks on, e.g. nozzle turbine blades. The surface defects preferably retain the radioactive gas. The defects can be identified by means of a radiographic silver halide emulsion or dispersion made intensive to high energy radiation which is put on the surface or held at a distance to it. Piazine, thiuram disulphide, nitro-1,2,3-benzothiazole or a combination of thiuram disulphide and piazine are amongst others suitable as desensitizing agents. To prevent the adsorbed gases from diffusing out of the defects, the surface can be coated with an insulating mass of e.g. a polymer. The silver halide emulsions are in the form of single, double, or ammoniac emulsions. (DG/LH) [de

  3. Dose Rate Determination from Airborne Gamma-ray Spectra

    DEFF Research Database (Denmark)

    Bargholz, Kim

    1996-01-01

    The standard method for determination of ground level dose rates from airborne gamma-ray is the integral count rate which for a constant flying altitude is assumed proportional to the dose rate. The method gives reasonably results for natural radioactivity which almost always has the same energy...

  4. Determination of the Optimum Harvest Window for Apples Using the Non-Destructive Biospeckle Method

    Directory of Open Access Journals (Sweden)

    Anna Skic

    2016-05-01

    Full Text Available Determination of the optimum harvest window plays a key role in the agro-food chain as the quality of fruit depends on the right harvesting time and appropriate storage conditions during the postharvest period. Usually, indices based on destructive measurements are used for this purpose, like the De Jager Index (PFW-1, FARS index and the most popular Streif Index. In this study, we proposed a biospeckle method for the evaluation of the optimum harvest window (OHW of the “Ligol” and “Szampion” apple cultivars. The experiment involved eight different maturity stages, of which four were followed by long cold storage and shelf life to assist the determination of the optimum harvest window. The biospeckle activity was studied in relation to standard quality attributes (firmness, acidity, starch, soluble solids content, Streif Index and physiological parameters (respiration and ethylene emission of both apple cultivars. Changes of biospeckle activity (BA over time showed moderate relationships with biochemical changes during apple maturation and ripening. The harvest date suggested by the Streif Index and postharvest quality indicators matched with characteristic decrease in BA. The ability of biospeckle method to characterize the biological state of apples was confirmed by significant correlations of BA with firmness, starch index, total soluble solids and Streif Index, as well as good match with changes in carbon dioxide and ethylene emission. However, it should be noted that correlations between variables changing over time are not as meaningful as independent observations. Also, it is a well-known property of the Pearson’s correlation that its value is highly susceptible to outlier data. Due to its non-selective nature the BA reflected only the current biological state of the fruit and could be affected by many other factors. The investigations showed that the optimum harvest window for apples was indicated by the characteristic drop of

  5. Determination of the Optimum Harvest Window for Apples Using the Non-Destructive Biospeckle Method.

    Science.gov (United States)

    Skic, Anna; Szymańska-Chargot, Monika; Kruk, Beata; Chylińska, Monika; Pieczywek, Piotr Mariusz; Kurenda, Andrzej; Zdunek, Artur; Rutkowski, Krzysztof P

    2016-05-10

    Determination of the optimum harvest window plays a key role in the agro-food chain as the quality of fruit depends on the right harvesting time and appropriate storage conditions during the postharvest period. Usually, indices based on destructive measurements are used for this purpose, like the De Jager Index (PFW-1), FARS index and the most popular Streif Index. In this study, we proposed a biospeckle method for the evaluation of the optimum harvest window (OHW) of the "Ligol" and "Szampion" apple cultivars. The experiment involved eight different maturity stages, of which four were followed by long cold storage and shelf life to assist the determination of the optimum harvest window. The biospeckle activity was studied in relation to standard quality attributes (firmness, acidity, starch, soluble solids content, Streif Index) and physiological parameters (respiration and ethylene emission) of both apple cultivars. Changes of biospeckle activity (BA) over time showed moderate relationships with biochemical changes during apple maturation and ripening. The harvest date suggested by the Streif Index and postharvest quality indicators matched with characteristic decrease in BA. The ability of biospeckle method to characterize the biological state of apples was confirmed by significant correlations of BA with firmness, starch index, total soluble solids and Streif Index, as well as good match with changes in carbon dioxide and ethylene emission. However, it should be noted that correlations between variables changing over time are not as meaningful as independent observations. Also, it is a well-known property of the Pearson's correlation that its value is highly susceptible to outlier data. Due to its non-selective nature the BA reflected only the current biological state of the fruit and could be affected by many other factors. The investigations showed that the optimum harvest window for apples was indicated by the characteristic drop of BA during pre

  6. Entry of Nd+3 ions into the LiYF4 matrix and determination of Nd+3 concentration by the nondestructing spectrophotometric method

    International Nuclear Information System (INIS)

    Tkachuk, A.M.; Poletimova, A.V.; Petrova, M.A.; Egorov, V.Yu.; Korolev, N.E.

    1991-01-01

    Entering of Nd 3+ ions into LiYF 4 lattice was investigation. Nondestructive spectrophotometric method for determining activator concentration in the crystal was developed. It enables to determine both the average integral concentration in the active element. Absorption cross sections were determined for a series of reference lines λ i with the lowest polarization degree. Values of β(λ i ) coefficients, enabling to determine the average neodymium concentration in the sample, are presented. Coefficient of neodymium entering into LiYF 4 lattice was determined: K nd =0.31+-0.02

  7. Determining effective radiation mutagen dose for garlic (Allium sativum L.)

    International Nuclear Information System (INIS)

    Taner, Y.; Kunter, B.

    2004-01-01

    This study was carried out to get database for future garlic mutation breeding studies. For this aim, 0, 5, 10, 15, 20, 25 and 30 Gy doses of Cs 137 (gamma-ray) were applied on garlic cloves as a physical mutagen. 50 cloves were used for each dose. Sixty days after treatment, germination rate and shoot development of cloves were determined. The Effective Mutagen Dose (ED 50 ) was calculated by regression analyses. According to the results, 4.455 Gy dose was found to be effective as ED 50 . (author)

  8. Dose Determination of Activated Charcoal in Management of ...

    African Journals Online (AJOL)

    measured by high performance liquid chromatography (HPLC) for dose determination of activated ... paracetamol, benzodiazepines and alcohol [11]. .... Stability. The stability (short term) of standard and amitriptyline sample solutions was ...

  9. Non-destructive Determination of Martensitic Content by Means of Magnetic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Niffenegger, M.; Bauer, R.; Kalkhof, D

    2003-07-01

    The detection of material degradation in a pre-cracked stage would be very advantageous. Therefore the main objective of the EC 5th Framework Programme Project CRETE (Contract No. FIS5-1999-00280) was to assess the capability and the reliability of innovative NDT-inspection techniques for the detection of material degradation, induced by low cycle fatigue (LCF) and neutron irradiation of metastable austenitic and ferritic low-alloy steel. Within work package WP6 and WP7 several project partners tested aged or irradiated samples, using various advanced measuring techniques, such as acoustic, magnetic and thermoelectric ones. These indirect methods require a careful interpretation of the measured signal in terms of micro-structural evolutions due to ageing of the material. Therefore the material had to be characterized in its undamaged, as well as in its damaged state. Based on results from former investigations, main attention was paid to the content of martensitic phase as an indicator for fatigue. Since most NDT-methods are considered as indirect methods for the detection of martensite, neutron diffraction was applied as a reference method for a quantitative determination of martensite. The material characterization performed at PSI and INSA de Lyon is published in the PSI Bericht Nr. 03-17, July 2003, (ISSN 1019-0643). The present report only describes the magnetic methods applied at PSI for the detection of material degradation and summarises the results obtained in WP3 of the CRETE project. The report is issued simultaneously as a PSI report and the CRETE work package WP3 report. At PSI the following magnetic methods were applied to LCF specimens: (1) Ferromaster for measuring the magnetic permeability, (2) Eddy current impedance measuring by means of a Giant Magneto Resistance sensor (GMR), (3) Remanence field measurements using high sensitive Fluxgate and SQUID sensors. With these methods three sets of fatigue specimens, made from different metastable

  10. Method and apparatus for determining the dose value of neutrons

    International Nuclear Information System (INIS)

    Burgkhardt, B.; Piesch, E.

    1976-01-01

    A method is provided for determining the dose value of neutrons leaving a body as thermal and intermediate neutrons after having been scattered in the body. A first dose value of thermal and intermediate neutrons is detected on the surface of the body by means of a first detector for neutrons which is shielded against thermal and intermediate neutrons not emerging from the body. A second detector is used to measure a second dose value of the thermal and intermediate neutrons not emerging from the body. A first correction factor based on the first and second values is obtained from a calibration diagram and is applied to the first dose value to determine a first corrected first dose value. 21 Claims, 6 Drawing Figures

  11. Determination of crossed gamma doses for garlic improvement (Allium Sativum)

    International Nuclear Information System (INIS)

    Perez Talavera, S.; Labrada, A.; Savin, V.

    1991-01-01

    The determination of four Cuban varieties of garlic was made so as to optimized the use of ionizing radiations in Cuba to breed vegetatively propagated crops such as garlic. The dose-effect regresion equation characterizing the radioinhibition zone of each crop was presented. We used a criteria to select the irradiation dose to be used in mutation breeding techniques based on obtaining height variability in the productive indicators, a survival and a number of garlic cloves high enough to allow and adequate reproduction of M1 plants. It was verified that this small inhibitor doses of radiations produced a higher percentage of good variability than the medium and high doses. With the use of small inhibitor doses (GR10-GR20) on the Guadalupe-15 garlic variety, 65 variety plants were obtained., 93.7% out of this number is higher than the control in the indicators considered

  12. Fast neutron radiation inactivation of Bacillus subtilis: Absorbed dose determination

    International Nuclear Information System (INIS)

    Song Lingli; Zheng Chun; Ai Zihui; Li Junjie; Dai Shaofeng

    2011-01-01

    In this paper, fast neutron inactivation effects of Bacillus subtilis were investigated with fission fast neutrons from CFBR-II reactor of INPC (Institute of Nuclear Physics and Chemistry) and mono-energetic neutrons from the Van de Graaff accelerator at Peking University. The method for determining the absorbed dose in the Bacillus subtilis suspension contained in test tubes is introduced. The absorbed dose, on account of its dependence on the volume and the form of confined state, was determined by combined experiments and Monte Carlo method. Using the calculation results of absorbed dose, the fast neutron inactivation effects on Bacillus subtilis were studied. The survival rates and absorbed dose curve was constructed. (authors)

  13. Nondestructive determination of plutonium mass in spent fuel: preliminary modeling results using the passive neutron Albedo reactivity technique

    International Nuclear Information System (INIS)

    Evans, Louise G.; Tobin, Stephen J.; Schear, Melissa A.; Menlove, Howard O.; Lee, Sang Y.; Swinhoe, Martyn T.

    2009-01-01

    There are a variety of motivations for quantifying plutonium (Pu) in spent fuel assemblies by means of nondestructive assay (NDA) including the following: strengthening the capability of the International Atomic Energy Agency (LAEA) to safeguard nuclear facilities, quantifying shipper/receiver difference, determining the input accountability value at pyrochemical processing facilities, providing quantitative input to burnup credit and final safeguards measurements at a long-term repository. In order to determine Pu mass in spent fuel assemblies, thirteen NDA techniques were identified that provide information about the composition of an assembly. A key motivation of the present research is the realization that none of these techniques, in isolation, is capable of both (1) quantifying the Pu mass of an assembly and (2) detecting the diversion of a significant number of rods. It is therefore anticipated that a combination of techniques will be required. A 5 year effort funded by the Next Generation Safeguards Initiative (NGSI) of the U.S. DOE was recently started in pursuit of these goals. The first two years involves researching all thirteen techniques using Monte Carlo modeling while the final three years involves fabricating hardware and measuring spent fuel. Here, we present the work in two main parts: (1) an overview of this NGSI effort describing the motivations and approach being taken; (2) The preliminary results for one of the NDA techniques - Passive Neutron Albedo Reactivity (PNAR). The PNAR technique functions by using the intrinsic neutron emission of the fuel (primarily from the spontaneous fission of curium) to self-interrogate any fissile material present. Two separate measurements of the spent fuel are made, both with and without cadmium (Cd) present. The ratios of the Singles, Doubles and Triples count rates obtained in each case are analyzed; known as the Cd ratio. The primary differences between the two measurements are the neutron energy spectrum

  14. Measured dose to ovaries and testes from Hodgkin's fields and determination of genetically significant dose

    International Nuclear Information System (INIS)

    Niroomand-Rad, A.; Cumberlin, R.

    1993-01-01

    The purpose of this study was to determine the genetically significant dose from therapeutic radiation exposure with Hodgkin's fields by estimating the doses to ovaries and testes. Phantom measurements were performed to verify estimated doses to ovaries and testes from Hodgkin's fields. Thermoluminescent LiF dosimeters (TLD-100) of 1 x 3 x 3 mm 3 dimensions were embedded in phantoms and exposed to standard mantle and paraaortic fields using Co-60, 4 MV, 6 MV, and 10 MV photon beams. The results show that measured doses to ovaries and testes are about two to five times higher than the corresponding graphically estimated doses for Co-60 and 4 MVX photon beams as depicted in ICRP publication 44. In addition, the measured doses to ovaries and testes are about 30% to 65% lower for 10 MV photon beams than for their corresponding Co-60 photon beams. The genetically significant dose from Hodgkin's treatment (less than 0.01 mSv) adds about 4% to the genetically significant dose contribution to medical procedures and adds less than 1% to the genetically significant dose from all sources. Therefore, the consequence to society is considered to be very small. The consequences for the individual patient are, likewise, small. 28 refs., 3 figs., 5 tabs

  15. Determination of the dose and dose distribution in radiation-linked polyolefins

    International Nuclear Information System (INIS)

    Andress, B.; Fischer, P.; Repp, H.H.; Roehl, P.

    1984-01-01

    The method serves the determination of the radiation dose and dose distribution in polyolefins cross-linked by electron beams; the cross-linking takes place in the presence of an additive which is inserted in the polyolefin by radiation. After the cross-linking the fraction of the additive which is not inserted will be extracted from the polyolefin and afterwards the total extinction of the polyolefin will be determined by photometry. This process allows in particular the determination of the quality of the irradiation conditions for the electron-beam cross-linking of medium-voltage cables insulated by polyolefins. (orig.) [de

  16. Determination of organ doses in radiographic imaging and diagnostic radiology

    International Nuclear Information System (INIS)

    Rathjen, M.

    1981-01-01

    Earlier publications on diagnostic radiation exposure commonly presented data on the gonadal dose. This emphasis on the genetic radiation risk is no longer valid in view of recent radiobiological findings; equal attention should be paid to the somatic radiation risk which is manifested by the induction of malignant neoplasms, e.g. in the lungs, red bone marrow, thyroid and female breast (ICRP 26). The permissible radiation doses for these organs and the gonals for routine diagnostic radiology are determined. A formula is established on the basis of terms from relevant publications (e.g. open-air dose, backscattering factor) and from the author's own measurements in an Alderson-Rando phantom (depth dose curves, dose decrements). The measurements were carried out using CaP 2 thermoluminescence dosemeters, and the organ doses for the various techniques of X-ray examination were calculated by computer. Calculations of this type will enable the radiologist to determine the patient exposure quickly and easily from the records kept according to Sect. 29 of the X-ray Ordinance. Experimental value from relevant publications are compared with the author's own results. (orig./HP) [de

  17. Determination of dose equivalent with tissue-equivalent proportional counters

    International Nuclear Information System (INIS)

    Dietze, G.; Schuhmacher, H.; Menzel, H.G.

    1989-01-01

    Low pressure tissue-equivalent proportional counters (TEPC) are instruments based on the cavity chamber principle and provide spectral information on the energy loss of single charged particles crossing the cavity. Hence such detectors measure absorbed dose or kerma and are able to provide estimates on radiation quality. During recent years TEPC based instruments have been developed for radiation protection applications in photon and neutron fields. This was mainly based on the expectation that the energy dependence of their dose equivalent response is smaller than that of other instruments in use. Recently, such instruments have been investigated by intercomparison measurements in various neutron and photon fields. Although their principles of measurements are more closely related to the definition of dose equivalent quantities than those of other existing dosemeters, there are distinct differences and limitations with respect to the irradiation geometry and the determination of the quality factor. The application of such instruments for measuring ambient dose equivalent is discussed. (author)

  18. Determination of tolerance dose uncertainties and optimal design of dose response experiments with small animal numbers

    International Nuclear Information System (INIS)

    Karger, C.P.; Hartmann, G.H.

    2001-01-01

    Background: Dose response experiments aim to determine the complication probability as a function of dose. Adjusting the parameters of the frequently used dose response model P(D)=1/[1+(D 50 /D) k ] to the experimental data, 2 intuitive quantities are obtained: The tolerance dose D 50 and the slope parameter k. For mathematical reasons, however, standard statistic software uses a different set of parameters. Therefore, the resulting fit parameters of the statistic software as well as their standard errors have to be transformed to obtain D 50 and k as well as their standard errors. Material and Methods: The influence of the number of dose levels on the uncertainty of the fit parameters is studied by a simulation for a fixed number of animals. For experiments with small animal numbers, statistical artifacts may prevent the determination of the standard errors of the fit parameters. Consequences on the design of dose response experiments are investigated. Results: Explicit formulas are presented, which allow to calculate the parameters D 50 and k as well as their standard errors from the output of standard statistic software. The simulation shows, that the standard errors of the resulting parameters are independent of the number of dose levels, as long as the total number of animals involved in the experiment, remains constant. Conclusion: Statistical artifacts in experiments containing small animal numbers may be prevented by an adequate design of the experiment. For this, it is suggested to select a higher number of dose levels, rather than using a higher number of animals per dose level. (orig.) [de

  19. Studies of absorbed dose determinations and spatial dose distributions for high energy proton beams

    International Nuclear Information System (INIS)

    Hiraoka, Takeshi

    1982-01-01

    Absolute dose determinations were made with three types of ionization chamber and a Faraday cup. Methane based tissue equivalent (TE) gas, nitrogen, carbon dioxide, air were used as an ionizing gas with flow rate of 10 ml per minute. Measurements were made at the entrance position of unmodulated beams and for a beam of a spread out Bragg peak at a depth of 17.3 mm in water. For both positions, the mean value of dose determined by the ionization chambers was 0.993 +- 0.014 cGy for which the value of TE gas was taken as unity. The agreement between the doses estimated by the ionization chambers and the Faraday cup was within 5%. Total uncertainty estimated in the ionization chamber and the Faraday cup determinations is 6 and 4%, respectively. Common sources of error in calculating the dose from ionization chamber measurements are depend on the factors of ion recombination, W value, and mass stopping power ratio. These factors were studied by both experimentally and theoretically. The observed values for the factors show a good agreement to the predicted one. Proton beam dosimetry intercomparison between Japan and the United States was held. Good agreement was obtained with standard deviation of 1.6%. The value of the TE calorimeter is close to the mean value of all. In the proton spot scanning system, lateral dose distributions at any depth for one spot beam can be simulated by the Gaussian distribution. From the Gaussian distributions and the central axis depth doses for one spot beam, it is easy to calculate isodose distributions in the desired field by superposition of dose distribution for one spot beam. Calculated and observed isodose curves were agreed within 1 mm at any dose levels. (J.P.N.)

  20. Ir-192 HDR transit dose and radial dose function determination using alanine/EPR dosimetry

    International Nuclear Information System (INIS)

    Calcina, Carmen S Guzman; Almeida, Adelaide de; Rocha, Jose R Oliveira; Abrego, Felipe Chen; Baffa, Oswaldo

    2005-01-01

    Source positioning close to the tumour in high dose rate (HDR) brachytherapy is not instantaneous. An increment of dose will be delivered during the movement of the source in the trajectory to its static position. This increment is the transit dose, often not taken into account in brachytherapeutic treatment planning. The transit dose depends on the prescribed dose, number of treatment fractions, velocity and activity of the source. Combining all these factors, the transit dose can be 5% higher than the prescribed absorbed dose value (Sang-Hyun and Muller-Runkel, 1994 Phys. Med. Biol. 39 1181-8, Nath et al 1995 Med. Phys. 22 209-34). However, it cannot exceed this percentage (Nath et al 1995). In this work, we use the alanine-EPR (electron paramagnetic resonance) dosimetric system using analysis of the first derivative of the signal. The transit dose was evaluated for an HDR system and is consistent with that already presented for TLD dosimeters (Bastin et al 1993 Int. J. Radiat. Oncol. Biol. Phys. 26 695-702). Also using the same dosimetric system, the radial dose function, used to evaluate the geometric dose degradation around the source, was determined and its behaviour agrees better with those obtained by Monte Carlo simulations (Nath et al 1995, Williamson and Nath 1991 Med. Phys. 18 434-48, Ballester et al 1997 Med. Phys. 24 1221-8, Ballester et al 2001 Phys. Med. Biol. 46 N79-90) than with TLD measurements (Nath et al 1990 Med. Phys. 17 1032-40)

  1. Dose determination of 600 MeV proton irradiated specimens

    International Nuclear Information System (INIS)

    Gavillet, D.

    1991-01-01

    The calculation method for the experimental determination of the atomic production cross section from the γ activity measurements are presented. This method is used for the determination of some isotope production cross sections for 600 MeV proton irradition in MANET steel, copper, tungsten, gold and titanium. The results are compared with some calculation. These values are used to determine the dose of specimens irradiated in the PIREX II facility. The results are discussed in terms of the irradiation parameters. A guide for the use of the production cross section determined in the dosimetry experiment are given. (author) tabs., refs

  2. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Kleiman, Norman Jay [Columbia University

    2013-11-30

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

  3. Nuclear fuel and/or fertile material element suitable for non-destructive determination of burn-up

    International Nuclear Information System (INIS)

    Muench, E.

    1976-01-01

    The invention refers to a nuclear fuel and/or fertile material element suitable for non-destructive burn-up analysis, where an isotope or a mixture of isotopes capable of being activated is provided for measuring the intensity of radiation emitted from radioactive nuclides, especially the intensity of gamma rays. The half-life of radioactive decay of the isotope or the mixture mentioned above after being activated is sufficiently large compared with the irradiation of the fuel and/or fertile material element in the nuclear reactor. (orig.) [de

  4. Committed effective dose determination in southern Brazilian cereal flours.

    Science.gov (United States)

    Scheibel, V; Appoloni, C R

    2013-01-01

    The health impact of radionuclide ingestion from foodstuffs was evaluated by the committed effective doses determined in eight commercial samples of South-Brazilian cereal flours (soy, wheat, cornmeal, cassava, rye, oat, barley and rice flours). The radioactivity traces of (228)Th, (228)Ra, (226)Ra, (40)K, (7)Be and (137)Cs were measured by gamma-ray spectrometry employing an HPGe detector of 66 % relative efficiency. The efficiency curve has taken into account the differences in densities and chemical composition between the matrix and the certified sample. The highest concentration levels of (228)Th and (40)K were 3.5±0.4 and 1469±17 Bq kg(-1) for soy flour, respectively, within the 95 % confidence level. The lower limit of detection for (137)Cs ranged from 0.04 to 0.4 Bq kg(-1). The highest committed effective dose was 0.36 μSv.y(-1) for (228)Ra in cassava flour (adults). All committed effective doses determined at the present work were lower than the International Atomic Energy Agency dose limit of 1 mSv.y(-1), to the public exposure.

  5. Committed effective dose determination in southern Brazilian cereal flours

    International Nuclear Information System (INIS)

    Scheibel, V.; Appoloni, C. R.

    2013-01-01

    The health impact of radionuclide ingestion from foodstuffs was evaluated by the committed effective doses determined in eight commercial samples of South-Brazilian cereal flours (soy, wheat, cornmeal, cassava, rye, oat, barley and rice flours). The radioactivity traces of 228 Th, 228 Ra, 226 Ra, 40 K, 7 Be and 137 Cs were measured by gamma-ray spectrometry employing an HPGe detector of 66 % relative efficiency. The efficiency curve has taken into account the differences in densities and chemical composition between the matrix and the certified sample. The highest concentration levels of 228 Th and 40 K were 3.5±0.4 and 1469±17 Bq kg -1 for soy flour, respectively, within the 95 % confidence level. The lower limit of detection for 137 Cs ranged from 0.04 to 0.4 Bq kg -1 . The highest committed effective dose was 0.36 μSv.y -1 for 228 Ra in cassava flour (adults). All committed effective doses determined at the present work were lower than the International Atomic Energy Agency dose limit of 1 mSv.y -1 , to the public exposure. (authors)

  6. How accurately can the peak skin dose in fluoroscopy be determined using indirect dose metrics?

    International Nuclear Information System (INIS)

    Jones, A. Kyle; Ensor, Joe E.; Pasciak, Alexander S.

    2014-01-01

    Purpose: Skin dosimetry is important for fluoroscopically-guided interventions, as peak skin doses (PSD) that result in skin reactions can be reached during these procedures. There is no consensus as to whether or not indirect skin dosimetry is sufficiently accurate for fluoroscopically-guided interventions. However, measuring PSD with film is difficult and the decision to do so must be madea priori. The purpose of this study was to assess the accuracy of different types of indirect dose estimates and to determine if PSD can be calculated within ±50% using indirect dose metrics for embolization procedures. Methods: PSD were measured directly using radiochromic film for 41 consecutive embolization procedures at two sites. Indirect dose metrics from the procedures were collected, including reference air kerma. Four different estimates of PSD were calculated from the indirect dose metrics and compared along with reference air kerma to the measured PSD for each case. The four indirect estimates included a standard calculation method, the use of detailed information from the radiation dose structured report, and two simplified calculation methods based on the standard method. Indirect dosimetry results were compared with direct measurements, including an analysis of uncertainty associated with film dosimetry. Factors affecting the accuracy of the different indirect estimates were examined. Results: When using the standard calculation method, calculated PSD were within ±35% for all 41 procedures studied. Calculated PSD were within ±50% for a simplified method using a single source-to-patient distance for all calculations. Reference air kerma was within ±50% for all but one procedure. Cases for which reference air kerma or calculated PSD exhibited large (±35%) differences from the measured PSD were analyzed, and two main causative factors were identified: unusually small or large source-to-patient distances and large contributions to reference air kerma from cone

  7. Dose rate determining factors of PWR primary water

    International Nuclear Information System (INIS)

    Terachi, Takumi; Kuge, Toshiharu; Nakano, Nobuo

    2014-01-01

    The relationship between dose rate trends and water chemistry has been studied to clarify the determining factors on the dose rates. Therefore dose rate trends and water chemistry of 11 PWR plants of KEPCO (Kansai Electric Power Co., Inc.) were summarized. It is indicated that the chemical composition of the oxide film, behaviour of corrosion products and Co-58/Co-60 ratio in the primary system have effected dose rate trends based on plant operation experiences for over 40 years. According to plant operation experiences, the amount of Co-58 has been decreasing with the increasing duration of SG (Steam Generator) usage. It is indicated that the stable oxide film formation on the inner surface of SG tubing, is a major beneficial factor for radiation sources reduction. On the other hand, the reduction of the amount of Co-60 for the long term has been not clearly observed especially in particular high dose plants. The primary water parameters imply that considering release and purification balance on Co-59 is important to prevent accumulation of source term in primary water. In addition, the effect of zinc injection, which relates to the chemical composition of oxide film, was also assessed. As the results, the amount of radioactive Co has been clearly decreased. The decreasing trend seems to correlate to the half-life of Co-60, because it is considered that the injected zinc prevents the uptake of radioactive Co into the oxide film on the inner surface of the components and piping. In this paper, the influence of water chemistry and the replacement experiences of materials on the dose rates were discussed. (author)

  8. Nondestructive analysis and development

    Science.gov (United States)

    Moslehy, Faissal A.

    1993-01-01

    This final report summarizes the achievements of project #4 of the NASA/UCF Cooperative Agreement from January 1990 to December 1992. The objectives of this project are to review NASA's NDE program at Kennedy Space Center (KSC) and recommend means for enhancing the present testing capabilities through the use of improved or new technologies. During the period of the project, extensive development of a reliable nondestructive, non-contact vibration technique to determine and quantify the bond condition of the thermal protection system (TPS) tiles of the Space Shuttle Orbiter was undertaken. Experimental modal analysis (EMA) is used as a non-destructive technique for the evaluation of Space Shuttle thermal protection system (TPS) tile bond integrity. Finite element (FE) models for tile systems were developed and were used to generate their vibration characteristics (i.e. natural frequencies and mode shapes). Various TPS tile assembly configurations as well as different bond conditions were analyzed. Results of finite element analyses demonstrated a drop in natural frequencies and a change in mode shapes which correlate with both size and location of disbond. Results of experimental testing of tile panels correlated with FE results and demonstrated the feasibility of EMA as a viable technique for tile bond verification. Finally, testing performed on the Space Shuttle Columbia using a laser doppler velocimeter demonstrated the application of EMA, when combined with FE modeling, as a non-contact, non-destructive bond evaluation technique.

  9. Methods of determining the effective dose in dental radiology

    International Nuclear Information System (INIS)

    Thilander-Klang, A.; Helmrot, E.

    2010-01-01

    A wide variety of X-ray equipment is used today in dental radiology, including intra-oral, ortho-pan-tomographic, cephalo-metric, cone-beam computed tomography (CBCT) and computed tomography (CT). This raises the question of how the radiation risks resulting from different kinds of examinations should be compared. The risk to the patient is usually expressed in terms of effective dose. However, it is difficult to determine its reliability, and it is difficult to make comparisons, especially when different modalities are used. The classification of the new CBCT units is also problematic as they are sometimes classified as CT units. This will lead to problems in choosing the best dosimetric method, especially when the examination geometry resembles more on an ordinary ortho-pan-tomographic examination, as the axis of rotation is not at the centre of the patient, and small radiation field sizes are used. The purpose of this study was to present different methods for the estimation of the effective dose from the equipment currently used in dental radiology, and to discuss their limitations. The methods are compared based on commonly used measurable and computable dose quantities, and their reliability in the estimation of the effective dose. (authors)

  10. Neuromuscular dose-response studies: determining sample size.

    Science.gov (United States)

    Kopman, A F; Lien, C A; Naguib, M

    2011-02-01

    Investigators planning dose-response studies of neuromuscular blockers have rarely used a priori power analysis to determine the minimal sample size their protocols require. Institutional Review Boards and peer-reviewed journals now generally ask for this information. This study outlines a proposed method for meeting these requirements. The slopes of the dose-response relationships of eight neuromuscular blocking agents were determined using regression analysis. These values were substituted for γ in the Hill equation. When this is done, the coefficient of variation (COV) around the mean value of the ED₅₀ for each drug is easily calculated. Using these values, we performed an a priori one-sample two-tailed t-test of the means to determine the required sample size when the allowable error in the ED₅₀ was varied from ±10-20%. The COV averaged 22% (range 15-27%). We used a COV value of 25% in determining the sample size. If the allowable error in finding the mean ED₅₀ is ±15%, a sample size of 24 is needed to achieve a power of 80%. Increasing 'accuracy' beyond this point requires increasing greater sample sizes (e.g. an 'n' of 37 for a ±12% error). On the basis of the results of this retrospective analysis, a total sample size of not less than 24 subjects should be adequate for determining a neuromuscular blocking drug's clinical potency with a reasonable degree of assurance.

  11. A single-aliquot OSL protocol using bracketing regenerative doses to accurately determine equivalent doses in quartz

    International Nuclear Information System (INIS)

    Folz, Elise; Mercier, Norbert

    1999-01-01

    In most cases, sediments show inherent heterogeneity in their luminescence behaviours and bleaching histories, and identical aliquots are not available: single-aliquot determination of the equivalent dose (ED) is then the approach of choice and the advantages of using regenerative protocols are outlined. Experiments on five laboratory bleached and dosed quartz samples, following the protocol described by Murray and Roberts (1998. Measurement of the equivalent dose in quartz using a regenerative-dose single aliquot protocol. Radiation Measurements 27, 171-184), showed the hazards of using a single regeneration dose: a 10% variation in the regenerative dose yielded some equivalent dose estimates that differed from the expected value by more than 5%. A protocol is proposed that allows the use of different regenerative doses to bracket the estimated equivalent dose. The measured ED is found to be in excellent agreement with the known value when the main regeneration dose is within 10% of the true equivalent dose

  12. A single-aliquot OSL protocol using bracketing regenerative doses to accurately determine equivalent doses in quartz

    CERN Document Server

    Folz, E

    1999-01-01

    In most cases, sediments show inherent heterogeneity in their luminescence behaviours and bleaching histories, and identical aliquots are not available: single-aliquot determination of the equivalent dose (ED) is then the approach of choice and the advantages of using regenerative protocols are outlined. Experiments on five laboratory bleached and dosed quartz samples, following the protocol described by Murray and Roberts (1998. Measurement of the equivalent dose in quartz using a regenerative-dose single aliquot protocol. Radiation Measurements 27, 171-184), showed the hazards of using a single regeneration dose: a 10% variation in the regenerative dose yielded some equivalent dose estimates that differed from the expected value by more than 5%. A protocol is proposed that allows the use of different regenerative doses to bracket the estimated equivalent dose. The measured ED is found to be in excellent agreement with the known value when the main regeneration dose is within 10% of the true equivalent dose.

  13. A non-destructive, ultrasonic method for the determination of internal pressure and gas composition in an LWR fuel rod on-going and future programme

    International Nuclear Information System (INIS)

    Ferrandis, J.; Leveque, G.; Villard, J.

    2006-01-01

    Several possible non-destructive methods have been investigated in the past to measure the internal gas pressure e.g., measurement of 85 Kr directly, or after accumulation in the plenum by freezing with liquid nitrogen. However no satisfactory resolution to the problem has been found, so at present there is no rapid and accurate method of determining the fission gas pressure in a fuel rod without puncturing the cladding. This procedure is time-consuming and expensive and as a consequence a relatively small number of measurements are generally made compared with the number of fuel rods irradiated. In this paper it is proposed a new method for the measurement of pressure that is: Non-destructive; Non-invasive (i.e., allows re-irradiation of the measured rod); Easy to operate - directly in the reactor pool; Can be used on the critical path; Is inexpensive compared with the methods currently in use. This method is also being adapted to the on line measurement of fission gas release on fuel irradiation in research reactors. This method is based on the application of acoustic technology

  14. Dose determination in irradiated chicken meat by ESR method

    International Nuclear Information System (INIS)

    Polat, M.

    1996-01-01

    In this work, the properties of the radicals produced in chicken bones have been investigated by ESR technique to determine the amount of dose applied to the chicken meats during the food irradiation. For this goal, the drumsticks from 6-8 weeks old chickens purchased from a local market were irradiated at dose levels of 0; 2; 4; 6; 8 and 10 kGy. Then, the ESR spectra of the powder samples prepared from the bones of the drumsticks have been investigated. Unirradiated chicken bones have been observed to show a weak ESR signal of single line character. CO-2 ionic radicals of axial symmetry with g=1.9973 and g=2.0025 were observed to be produced in irradiated samples which would give rise to a three peaks ESR spectrum. In addition, the signal intensities of the samples were found to depend linearly on the irradiation dose in the dose range of 0-10 kGy. The powder samples prepared from chicken leg bones cleaned from their meats and marrow and irradiated at dose levels of 1, 2, 3, 4, 5, 6, B, 10, 12,14, 16, 1B, 20 and 22 kGy were used to get the dose-response curve. It was found that this curve has biphasic character and that the dose yield was higher in the 12-1B kGy dose range and a decrease appears in this curve over 18 kGy. The radical produced in the bones were found to be the same whether the irradiation was performed after stripping the meat and removing the marrow from the bone or before the stripping. The ESR spectra of both irradiated and non irradiated samples were investigated in the temperature range of 100 K-450 K and changes in the ESR spectra of CO-2 radical have been studied. For non irradiated samples (controls). the signal intensities were found to decrease when the temperature was increased. The same investigation has been carried out for irradiated samples and it was concluded that the signal intensities relative to the peaks of the radical spectrum increase in the temperature range of 100 K-330 K, then they decrease over 330 K. The change in the

  15. Calibration of ionization chambers and determination of the absorbed doses

    International Nuclear Information System (INIS)

    RANDRIANTSEHENO, H.F

    1996-01-01

    In order to further improve the accuracy of dosimetric measurements in radiation therapy, the IAEA and WHO supported the establishment of Secondary Standard Dosimetry Laboratory (SSDLs). These SSDLs bridge the gap between the primary measurement standards and the user of ionizing radiation by providing the latter with calibrations against the SSDLs' secondary standards and by giving technical advice and assistance. However, a properly calibrated dosimeter is just necessary first condition for the determination of the dose. It has been demonstrated that the success or failure of radiation treatment depends on the absorbed dose delivered to the tumour and that this should not vary by more than a few per cent from described values. [fr

  16. Concepts for dose determination in flat-detector CT

    International Nuclear Information System (INIS)

    Kyriakou, Yiannis; Deak, Paul; Langner, Oliver; Kalender, Willi A

    2008-01-01

    Flat-detector computed tomography (FD-CT) scanners provide large irradiation fields of typically 200 mm in the cranio-caudal direction. In consequence, dose assessment according to the current definition of the computed tomography dose index CTDI L=100mm , where L is the integration length, would demand larger ionization chambers and phantoms which do not appear practical. We investigated the usefulness of the CTDI concept and practical dosimetry approaches for FD-CT by measurements and Monte Carlo (MC) simulations. An MC simulation tool (ImpactMC, VAMP GmbH, Erlangen, Germany) was used to assess the dose characteristics and was calibrated with measurements of air kerma. For validation purposes measurements were performed on an Axiom Artis C-arm system (Siemens Medical Solutions, Forchheim, Germany) equipped with a flat detector of 40 cm x 30 cm. The dose was assessed for 70 kV and 125 kV in cylindrical PMMA phantoms of 160 mm and 320 mm diameter with a varying phantom length from 150 to 900 mm. MC simulation results were compared to the values obtained with a calibrated ionization chambers of 100 mm and 250 mm length and to thermoluminesence (TLD) dose profiles. The MCs simulations were used to calculate the efficiency of the CTDI L determination with respect to the desired CTDI ∞ . Both the MC simulation results and the dose distributions obtained by MC simulation were in very good agreement with the CTDI measurements and with the reference TLD profiles, respectively, to within 5%. Standard CTDI phantoms which have a z-extent of 150 mm underestimate the dose at the center by up to 55%, whereas a z-extent of ≥600 mm appears to be sufficient for FD-CT; the baseline value of the respective profile was within 1% to the reference baseline. As expected, the measurements with ionization chambers of 100 mm and 250 mm offer a limited accuracy, whereas an increased integration length of ≥600 mm appeared to be necessary to approximate CTDI ∞ in within 1%. MC

  17. Concepts for dose determination in flat-detector CT

    Science.gov (United States)

    Kyriakou, Yiannis; Deak, Paul; Langner, Oliver; Kalender, Willi A.

    2008-07-01

    Flat-detector computed tomography (FD-CT) scanners provide large irradiation fields of typically 200 mm in the cranio-caudal direction. In consequence, dose assessment according to the current definition of the computed tomography dose index CTDIL=100 mm, where L is the integration length, would demand larger ionization chambers and phantoms which do not appear practical. We investigated the usefulness of the CTDI concept and practical dosimetry approaches for FD-CT by measurements and Monte Carlo (MC) simulations. An MC simulation tool (ImpactMC, VAMP GmbH, Erlangen, Germany) was used to assess the dose characteristics and was calibrated with measurements of air kerma. For validation purposes measurements were performed on an Axiom Artis C-arm system (Siemens Medical Solutions, Forchheim, Germany) equipped with a flat detector of 40 cm × 30 cm. The dose was assessed for 70 kV and 125 kV in cylindrical PMMA phantoms of 160 mm and 320 mm diameter with a varying phantom length from 150 to 900 mm. MC simulation results were compared to the values obtained with a calibrated ionization chambers of 100 mm and 250 mm length and to thermoluminesence (TLD) dose profiles. The MCs simulations were used to calculate the efficiency of the CTDIL determination with respect to the desired CTDI∞. Both the MC simulation results and the dose distributions obtained by MC simulation were in very good agreement with the CTDI measurements and with the reference TLD profiles, respectively, to within 5%. Standard CTDI phantoms which have a z-extent of 150 mm underestimate the dose at the center by up to 55%, whereas a z-extent of >=600 mm appears to be sufficient for FD-CT; the baseline value of the respective profile was within 1% to the reference baseline. As expected, the measurements with ionization chambers of 100 mm and 250 mm offer a limited accuracy, whereas an increased integration length of >=600 mm appeared to be necessary to approximate CTDI∞ in within 1%. MC simulations

  18. Non-destructive Determination of Disintegration Time and Dissolution in Immediate Release Tablets by Terahertz Transmission Measurements.

    Science.gov (United States)

    Markl, Daniel; Sauerwein, Johanna; Goodwin, Daniel J; van den Ban, Sander; Zeitler, J Axel

    2017-05-01

    The aim of this study was to establish the suitability of terahertz (THz) transmission measurements to accurately measure and predict the critical quality attributes of disintegration time and the amount of active pharmaceutical ingredient (API) dissolved after 15, 20 and 25 min for commercial tablets processed at production scale. Samples of 18 batches of biconvex tablets from a production-scale design of experiments study into exploring the design space of a commercial tablet manufacturing process were used. The tablet production involved the process steps of high-shear wet granulation, fluid-bed drying and subsequent compaction. The 18 batches were produced using a 4 factor split plot design to study the effects of process changes on the disintegration time. Non-destructive and contactless terahertz transmission measurements of the whole tablets without prior sample preparation were performed to measure the effective refractive index and absorption coefficient of 6 tablets per batch. The disintegration time (R 2  = 0.86) and API dissolved after 15 min (R 2  = 0.96) linearly correlates with the effective refractive index, n eff , measured at terahertz frequencies. In contrast, no such correlation could be established from conventional hardness measurements. The magnitude of n eff represents the optical density of the sample and thus it reflects both changes in tablet porosity as well as granule density. For the absorption coefficient, α eff , we observed a better correlation with dissolution after 20 min (R 2  = 0.96) and a weaker correlation with disintegration (R 2  = 0.83) compared to n eff . The measurements of n eff and α eff provide promising predictors for the disintegration and dissolution time of tablets. The high penetration power of terahertz radiation makes it possible to sample a significant volume proportion of a tablet without any prior sample preparation. Together with the short measurement time (seconds), the potential to

  19. Hyperglycemia in critical patients: Determinants of insulin dose choice

    Directory of Open Access Journals (Sweden)

    Aline Klitzke Paliosa

    Full Text Available Summary Objective: To identify factors that can determine the choice of intermittent subcutaneous regular insulin dose in critically ill patients with hyperglycemia. Method: Cross-sectional study in a general adult ICU with 26 beds, data collected between September and October 2014. The variables analyzed were: sex, age, previous diagnosis of diabetes mellitus, use of corticosteroids, use of lactulose, sepsis, fasting, enteral nutrition, use of dextrose 5% in water, NPH insulin prescription and blood glucose level. Patients with one or more episodes of hyperglycemia (blood glucose greater than 180 mg/dL were included as a convenience sample, not consecutively. Those with continuous insulin prescription were excluded from analysis. Results: We included 64 records of hyperglycemia observed in 22 patients who had at least one episode of hyperglycemia. The median administered subcutaneous regular human insulin was 6 IU and among the factors evaluated only blood glucose levels were associated with the choice of insulin dose administered. Conclusion: Clinical characteristics such as diet, medications and diagnosis of diabetes mellitus are clearly ignored in the decision-making regarding insulin dose to be administered for glucose control in critically ill patients with hyperglycemia.

  20. Study of development of non-destructive method for determining FGR from high burned PWR type fuel rod

    International Nuclear Information System (INIS)

    Yanagisawa, Kazuaki; Miyanishi, Hideyuki; Kitagawa, Isamu; Iida, Shozo; Ito, Tadaharu; Amano, Hidetoshi.

    1991-11-01

    Experimental study was made to evaluate the FGR (Fission Product Gas Release) from high burned PWR type fuel rods by means of non-destructive method through measurement of the gamma activity of 85 Kr isotope which was accumulated in the fuel top plenum. Experimental result shows that it is possible to know the amounts of FGR at fuel plenum by the equations given in the followings. FGR = 0.28C/V f or FGR = 0.07C where, FGR (%) is the amounts of Xe and Kr released from UO 2 fuel, C (counts/h) the radioactivity of 85 Kr at plenum of the tested fuel rod and V f (ml) the plenum volume of the tested fuel rod, respectively. The present study was made by using 14 x 14 PWR type fuel rods preirradiated up to the burn-up of 42.1 MWd/kgU, followed by the pulse irradiation at Nuclear Safety Research Reactor of Japan Atomic Energy Research Institute (JAERI). The FGR of the tested segmented fuel rods were measured by puncturing and found to range from 0.6% to 12% according to the magnitude of the deposited energy given by pulse. Estimated experimental error bands against the above equations were within plus minus 30%. (author)

  1. A Semiempirical Approach to the Determination of Daily Erythemal Doses.

    Science.gov (United States)

    Silva, Abel A; Yamamoto, Ana L C; Corrêa, Marcelo P

    2018-02-15

    The maintenance of ground-based instruments to measure the incidence of ultraviolet radiation (UVR) from the Sun demands strict and well-developed procedures. A piece of equipment can be out of service for a couple of weeks or months for calibration, repair or even the improvement of the facilities where it has been set up. However, the replacement of an instrument in such circumstances can be logistically and financially prohibitive. On the other hand, the lack of data can jeopardize a long-term experiment. In this study, we introduce a semiempirical approach to the determination of the theoretical daily erythemal dose (DED t ) for periods of instrumental absence in a tropical site. The approach is based on 5 years of ground-based measurements of daily erythemal dose (DED) linearly correlated with parameters of total ozone column (TOC) and reflectivity (R PC ) from the Ozone Monitoring Instrument (OMI) and the cosine of solar zenith angle at noon (SZA n ). Seventeen months of missing ground-based data were replaced with DED t , leading to a complete 5-year series of data. The lowest and the highest values of typical DED were 2411 ± 322 J m -2 (1σ) (winter) and 5263 ± 997 J m -2 (summer). The monthly integrated erythemal dose (mED) varied from 59 kJ m -2 (winter) to 162 kJ m -2 (summer). Both of them depended mainly on cos(SZA n ) and R PC . The 12-month integrated erythemal dose (12-ED) ranged from 1350 kJ m -2 to 1546 kJ m -2 , but it can depend significantly on other atmospheric parameter (maybe aerosols) not explicitly considered here. © 2018 The American Society of Photobiology.

  2. Non-destructive Engineering

    International Nuclear Information System (INIS)

    Ko, Jin Hyeon; Ryu, Taek In; Ko, Jun Bin; Hwang, Yong Hwa

    2006-08-01

    This book gives descriptions of non-destructive engineering on outline of non-destructive test, weld defects, radiographic inspection radiography, ultrasonic inspection, magnetic particle testing, liquid penetrant testing, eddy current inspection method, strain measurement, acoustic emission inspection method, other non-destructive testing like leakage inspection method, and non-destructive mechanics for fault analysis such as Griffiths creaking theory, and stress analysis of creaking.

  3. Determining absorbed dose of Ramsar people from natural radioactivity

    International Nuclear Information System (INIS)

    Ismaieli; Abdolreza

    1999-01-01

    Radiation exposure versus natural resources of environment is in external form. Especially, in some regions of the world radionuclides assembling in soils caused background of high radioactivity. Ramsar is one of these regions. The main purpose is to estimate gamma radiation exposure inside and outside of residential buildings in Ramsar and the suburbs and to present exposure map of Ramsar; also estimating internal exposure of radon gas and obtaining effective dose of Ramsar population. There for, SAPOS 90M gamma monitor and RSS-112 and Na I(Tl) scintillator were used. To determine the concentration of 226 Ra, 232 Th, 40 K in soil and building materials gamma spectrometer and Germanium detector were used. In addition to exposure rate of different sections of Ramsar and its suburbs, 200 residential houses with high exposure rate and more than 600 ones with normal exposure rate were determined. The results of measurement were respectively 11μRh -1 to 3 μRh -1 in indoor region and 11μRh -1 to 2μR -1 in indoor regions. Annual gamma exposure was 5.99+-18.01 mSv. Maximum of annual gamma exposure rate of this region is 131 mSv. The estimated radon dose, through previous measurement is approximated to 14.67+-39.14 mSv annually. normal exposure is respectively 8μRh -1 to 17μRh -1 in outdoor regions and 10μRh -1 to 130μRh -1 in indoor regions. Annual exposure rate of gamma radiation is 0.68+-0.01 mSv and estimated radon gas from indoor and outdoor exposure for effective dose is 2.34+ 0 .02 mSv

  4. A radon progeny sampler for the determination of effective dose

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, S.B. [Australian Radiation Laboratory, Victoria (Australia)

    1997-12-01

    The design and simulated performance is described of a two-stage sampler (HE-Sampler) for {sup 222}Rn progeny. This HE-Sampler has a collection efficiency optimised to match the particle size dependency of the radon progeny dose conversion factor (DCF), derived from the latest Respiratory Tract Model of the International Commission on Radiological Protection, as implemented in the computer code RADEP. The He-Sampler comprises a wire screen pre-separator, matched to the nasal deposition, and a wire screen collector, matched to the respiratory tract collection. This HE-Sampler allows for the estimation of the radiation dose from the inhalation of {sup 222}Rn progeny, derived from two concurrent alpha particle activity measurements, one on the HE-Sampler screen collector and one on a reference filter sample. As a first approximation, the DCF is proportional to the collected fraction. The HE-Sampler response was simulated for a range of radon progeny size distributions to determine the error in the estimated DCF values. The simulation results show that the HE-Sampler is relatively insensitive to variations in sampling rate and in the screen parameters, particularly for environmental exposure. (Author).

  5. Absorbed dose determination in photon fields using the tandem method

    International Nuclear Information System (INIS)

    Marques Pachas, J.F.

    1999-01-01

    The purpose of this work is to develop an alternative method to determine the absorbed dose and effective energy of photons with unknown spectral distributions. It includes a 'tandem' system that consists of two thermoluminescent dosemeters with different energetic dependence. LiF: Mg, Ti, CaF 2 : Dy thermoluminescent dosemeters and a Harshaw 3500 reading system are employed. Dosemeters are characterized with 90 Sr- 90 Y, calibrated with the energy of 60 Co and irradiated with seven different qualities of x-ray beams, suggested by ANSI No. 13 and ISO 4037. The answers of each type of dosemeter are adjusted to a function that depends on the effective energy of photons. The adjustment is carried out by means of the Rosenbrock minimization algorithm. The mathematical model used for this function includes five parameters and has a gauss and a straight line. Results show that the analytical functions reproduce the experimental data of the answers, with a margin of error of less than 5%. The reason of the answers of the CaF 2 : Dy and LiF: Mg, Ti, according to the energy of the radiation, allows us to establish the effective energy of photons and the absorbed dose, with a margin of error of less than 10% and 20% respectively

  6. Determination of Entrance Skin Doses and Organ Doses for Medical X Ray Examinations

    International Nuclear Information System (INIS)

    Tung, C.J.; Cheng, C.Y.; Chao, T.C.; Tsai, H.Y.

    1999-01-01

    A national survey of patient doses for diagnostic X ray radiographs is planned in Taiwan. Entrance skin doses and organ doses for all installed X ray machines will be investigated. A pilot study has been carried out for the national survey to develop a protocol for the dose assessment. Entrance skin doses and organ doses were measured by thermoluminescence dosemeters and calculated by Monte Carlo simulations for several X ray examinations. The conversion factor from free air entrance absorbed dose to entrance skin dose was derived. A formula for the computation of entrance skin doses from inputs of kV p , mA.s, source to skin distance, aluminium filtration, and generator rectifying was constructed. Organ doses were measured using a RANDO phantom and calculated using a mathematical phantom. All data will be passed to the Atomic Energy Council for developing a programme of national survey and regulatory controls for diagnostic X ray examinations. (author)

  7. Determination of uranium in soil with emphasis on dose assessment

    International Nuclear Information System (INIS)

    Vidic, A.; Ilic, Z.; Deljkic, D.; Repinc, U.; Benedik, Lj.; Maric, S.

    2005-01-01

    Uranium is present naturally in the earth crust and has three isotopes with long half-lives. These isotopes are 2 38U (99.27% natural abundance), 2 35U (0.72% natural abundance) and 2 34U (0.006% natural abundance). Isotope 2 35U is a valuable fuel for nuclear power plants. During the manufacture of nuclear fuel the concentration of 2 35U is increased. Depleted uranium (DU) is a waste product of this enrichment process and typically contains about 99.8% 2 38U , 0.2% 2 35U and 0.0006% 2 34U in mass. Due to its high density and other physical properties, DU is used in munitions designed to penetrate armour plate. DU weapons were used during the Balkan war in Bosnia and Herzegovina. It was estimated, that nearly 10,000 projectiles were fired or 3 tonnes of DU used in BandH. The aim of this work was to determine uranium radioisotopes in soil and air collected in Hadzici (near Sarajevo). The investigated area is a former military base used for the production and maintenance of tanks and other heavy military vehicles. During a NATO attack in 1995, about 1,500 rounds were fired at the site. The specific activities of 2 38U found in soil ranged from 28 Bq/kg to 55 Bq/kg. We found higher specific activities in some foci, in the range from 143 Bq/kg to 810 Bq/kg. The specific activities of uranium isotopes in the air were determined using simple dust loading approach. The results served to calculate the annual effective dose that could be received by individual workers at the site and by general population from the surrounding area. Radioactivity measurements in the environment of Hadzici showed that the annual effective dose for general population was less than 20 micro Sv.(author)

  8. Determining profile of dose distribution for PD-103 brachytherapy source

    International Nuclear Information System (INIS)

    Berkay, Camgoz; Mehmet, N. Kumru; Gultekin, Yegin

    2006-01-01

    Full text: Brachytherapy is a particular radiotherapy for cancer treatments. By destructing cancerous cells using radiation, the treatment proceeded. When alive tissues are subject it is hazardous to study experimental. For brachytherapy sources generally are studied as theoretical using computer simulation. General concept of the treatment is to locate the radioactive source into cancerous area of related tissue. In computer studies Monte Carlo mathematical method that is in principle based on random number generations, is used. Palladium radioisotope is LDR (Low radiation Dose Rate) source. Main radioactive material was coated with titanium cylinder with 3mm length, 0.25 mm radius. There are two parts of Pd-103 in the titanium cylinder. It is impossible to investigate differential effects come from two part as experimental. Because the source dimensions are small compared with measurement distances. So there is only simulation method. In dosimetric studies it is aimed to determine absorbed dose distribution in tissue as radial and angular. In nuclear physics it is obligation to use computer based methods for researchers. Radiation studies have hazards for scientist and people interacted with radiation. When hazard exceed over recommended limits or physical conditions are not suitable (long work time, non economical experiments, inadequate sensitivity of materials etc.) it is unavoidable to simulate works and experiments before practices of scientific methods in life. In medical area, usage of radiation is required computational work for cancer treatments. Some computational studies are routine in clinics and other studies have scientific development purposes. In brachytherapy studies there are significant differences between experimental measurements and theoretical (computer based) output data. Errors of data taken from experimental studies are larger than simulation values errors. In design of a new brachytherapy source it is important to consider detailed

  9. Determination of Absorbed Dose Using a Dosimetric Film

    International Nuclear Information System (INIS)

    Scarlat, F.; Scarisoreanu, A.; Oane, M.; Badita, E.; Mitru, E.

    2009-01-01

    This paper presents the absorbed dose measurements by means of the irradiated dosimetric reference films. The dose distributions were made by MULTIDATA film densitometer using RTD-4 software, in INFLPR Linear Accelerator Department

  10. Determination of the integral dose in CT of the neurocranium

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, H.; Mandl, H.; Hofmann, W.; Grobovschek, M.

    1985-12-01

    The amount of exposure of the cranium is calculated on the basis of the measured dose distribution in craniocaudal direction and on the axial planes of the Alderson phantom. The integral dose of the cranium and the local dose at sensitive organs are used as a measure of radiation exposure. (orig.).

  11. Equivalent dose determination in foraminifera: analytical description of the CO2--signal dose-response curve

    International Nuclear Information System (INIS)

    Hoffmann, D.; Woda, C.; Mangini, A.

    2003-01-01

    The dose-response of the CO 2 - signal (g=2.0006) in foraminifera with ages between 19 and 300 ka is investigated. The sum of two exponential saturation functions is an adequate function to describe the dose-response curve up to an additional dose of 8000 Gy. It yields excellent dating results but requires an artificial doses of at least 5000 Gy. For small additional doses of about 500 Gy the single exponential saturation function can be used to calculate a reliable equivalent dose D E , although it does not describ the dose-response for higher doses. The CO 2 - -signal dose-response indicates that the signal has two components of which one is less stable than the other

  12. Determination of the radiation dose to the body due to external radiation

    International Nuclear Information System (INIS)

    Drexler, G.; Eckerl, H.

    1985-01-01

    Section 63 of the Radiation Protection Ordinance defines the basic requirement, determination of radiation dose to the body. The determination of dose equivalents for the body is the basic step in practical monitoring of dose equivalents or dose limits with regard to individuals or population groups, both for constant or varying conditions of exposure. The main field of monitoring activities is the protection of persons occupationally exposed to ionizing radiation. Conversion factors between body doses and radiation quantities are explained. (DG) [de

  13. Handbook of nondestructive evaluation

    National Research Council Canada - National Science Library

    Hellier, Charles

    2013-01-01

    "Fully revised to cover the latest nondestructive testing (NDT) procedures, this practical resource reviews established and emerging methods for examining materials without destroying them or altering their structure...

  14. Non-destructive γ-spectrometric determination of mercury and gold in sea water after preconcentration by lead sulphide

    International Nuclear Information System (INIS)

    Alexandrov, S.

    1976-01-01

    A method is described for determination of mercury and gold in sea-water, based on preconcentration of these elements by retention on a column of lead sulphide at pH1 (nitric and sulphuric acids), and γ-spectrometry. Mercury (0.8 +-0.2 μg/l) and gold (6 +- 3 ng/l) have been determined in a sample from the Black Sea, taken near Varna. (author)

  15. Boron dose determination for BNCT using Fricke and EPR dosimetry

    International Nuclear Information System (INIS)

    Wielopolski, L.; Ciesielski, B.

    1995-01-01

    In Boron Neutron Capture Therapy (BNCT) the dominant dose delivered to the tumor is due to α and 7 Li charged particles resulting from a neutron capture by 10 B and is referred to herein as the boron dose. Boron dose is directly attributable to the following two independent factors, one boron concentration and the neutron capture energy dependent cross section of boron, and two the energy spectrum of the neutrons that interact with boron. The neutron energy distribution at a given point is dictated by the incident neutron energy distribution, the depth in tissue, geometrical factors such as beam size and patient's dimensions. To account for these factors can be accommodated by using Monte Carlo theoretical simulations. However, in conventional experimental BNCT dosimetry, e.g., using TLDs or ionization chambers, it is only possible to estimate the boron dose. To overcome some of the limitations in the conventional dosimetry, modifications in ferrous sulfate dosimetry (Fricke) and Electron Paramagnetic Resonance (EPR) dosimetry in alanine, enable to measure specifically boron dose in a mixed gamma neutron radiation fields. The boron dose, in either of the dosimeters, is obtained as a difference between measurements with boronated and unboronated dosimeters. Since boron participates directly in the measurements, the boron dosimetry reflects the true contribution, integral of the neutron energy spectrum with boron cross section, of the boron dose to the total dose. Both methods are well established and used extensively in dosimetry, they are presented briefly here

  16. Dose determination in breast tumor in brachytherapy using Iridium-192

    International Nuclear Information System (INIS)

    Okuno, S.F.

    1984-01-01

    Thermoluminescent dosimetry studies in vivo and in vitro aiming to determing radiation dose in the breast tumor, in brachytherapy using Iridium-192 was done. The correlation between radiation doses in tumor and external surface of the breast was investigated for correcting the time interval of radiation source implantation. (author) [pt

  17. Dose Determination of Activated Charcoal in Management of ...

    African Journals Online (AJOL)

    Purpose: To assess the doses of activated charcoal currently used in the management of acute amitriptyline-induced drug poisoning and explore the possibility of using lower doses. Methods: Albino male Wistar rats, weighing 200 ± 20 g, were used for the study. The animals were divided into four groups of eight animals ...

  18. A new non-destructive and standardless method for the determination of thin films by XRF measurement

    International Nuclear Information System (INIS)

    Gries, W.H.; Wybenga, F.T.

    1981-01-01

    The thickness of thin uniform films can be determined by measuring the signal ratio of a fluorescent line at two different take-off angles and using the result in either of two mathematical relationships which link the ratio to the film thickness. A zinc sulphide film on silica is used as an example for application of this method

  19. Nondestructive determination of lead, cadmium, tin, antimony, and barium in ceramic glazes by radioisotope X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Anderson, D.L.; Cunningham, W.C.

    1996-01-01

    Quantitation capabilities of radioisotope X-ray fluorescence spectrometry (RXRFS) for determining lead, cadmium, tin, antimony, and barium in ceramic glazes were investigated. Twenty-one air-dried glazes and 85 fired glazes on test tiles were analyzed by using 109 Cd and 57 Co excitation sources. Accurate Pb determinations, with limits of detection (LODs) of about 0.3 mg/cm 2 for 5 min counting times, were achieved by using the 75 keV Κ α1 X-ray photopeak and a Pb foil calibration procedure. Cd, Sn, Sb, and Ba concentrations were determined with LODs from about 0.5 to 1.5 mg/cm 2 . For Pb and Ba, results obtained by using absorption corrections based only on element concentrations determined by RXRFS and an iterative approach led to analytical biases of ≤4% relative to results obtained by using corrections based on known total element compositions. Biases were more severe for Cd, Sn, and Sb because lower X-ray energies were involved and sensitivities varied as a function of matrix Pb content. Pb concentrations were above LODs (1.3-40 mg/cm 2 ) in 39 of 47 fired open-quotes food-safeclose quotes glazes and in 33 of the other 38 fired glazes (0.4-39 mg/cm 2 ). 15 refs., 9 figs., 9 tabs

  20. Conversion coefficients for determining organ doses in paediatric spine radiography

    Energy Technology Data Exchange (ETDEWEB)

    Seidenbusch, Michael; Schneider, Karl [Ludwig-Maximilians-University of Munich, Institute of Clinical Radiology - Paediatric Radiology, Muenchen (Germany)

    2014-04-15

    Knowledge of organ and effective doses achieved during paediatric x-ray examinations is an important prerequisite for assessment of radiation burden to the patient. Conversion coefficients for reconstruction of organ and effective doses from entrance doses for segmental spine radiographs of 0-, 1-, 5-, 10-, 15- and 30-year-old patients are provided regarding the Guidelines of Good Radiographic Technique of the European Commission. Using the personal computer program PCXMC developed by the Finnish Centre for Radiation and Nuclear Safety (Saeteilyturvakeskus STUK), conversion coefficients for conventional segmental spine radiographs were calculated performing Monte Carlo simulations in mathematical hermaphrodite phantom models describing patients of different ages. The clinical variation of beam collimation was taken into consideration by defining optimal and suboptimal radiation field settings. Conversion coefficients for the reconstruction of organ doses in about 40 organs and tissues from measured entrance doses during cervical, thoracic and lumbar spine radiographs of 0-, 1-, 5-, 10-, 15- and 30-year-old patients were calculated for the standard sagittal and lateral beam projections and the standard focus detector distance of 115 cm. The conversion coefficients presented may be used for organ dose assessments from entrance doses measured during spine radiographs of patients of all age groups and all field settings within the optimal and suboptimal standard field settings. (orig.)

  1. Application of neutron activation analysis to biological materials. Pt. 4. Approach to simultaneous determination of trace elements in human eye tissues with non-destructive neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, T; Bando, M; Nakajima, A [Juntendo Univ., Tokyo (Japan). School of Medicine; Terai, M [Tokyo Metropolitan Univ. (Japan). Faculty of Science; Suzuki-Yasumoto, M [National Inst. of Radiological Sciences, Chiba (Japan)

    1980-01-01

    Fourteen trace elements (short-lived nuclides: Al, Br, Cu, Mn and V; long-lived nuclides: Ag, Au, Cd, Co, Cr, Fe, Sc, Se and Zn) in human eye tissues are determined simultaneously by non-destructive neutron activation analysis. The quantity of Al, Br, Fe, Se and Zn in the eye tissues (about 1 to more than 10 ..mu..g/g dry weight tissue) seems to be higher than that of other trace elements, although the content of each trace element in individual tissue is scattered in a wide range. Conjunctiva, iris (+ciliary body) and choroid (+pigment epithelium) seem to contain larger amount of various trace elements than other eye tissues. From correlation studies it is evident that the relative distribution of 14 trace elements in various eye tissues are similar, and furthermore the content of trace elements in the eye tissues may be correlated in each of the three groups (group A: Cd, Se and Zn; group B: Al, Cr, Fe, Se and V; group C: Al, Au, Fe and Se).

  2. A novel non-destructive manner for quantitative determination of plumpness of live Eriocheir sinensis using low-field nuclear magnetic resonance.

    Science.gov (United States)

    Song, Lingling; Zhang, Hongcai; Chen, Shunsheng

    2018-03-01

    The present study investigated the quantitative and non-destructive determination of Eriocheir sinensis' plumpness during four mature stages using low field-nuclear magnetic resonance (LF- 1 H NMR). Normalized lipid volume of live E. sinensis was calculated from Sept to Dec using 3D LF- 1 H nuclear magnetic imaging (MRI) and the validity of proposed technique was compared and verified with traditional Soxhlet extraction and live dissection method, respectively. The results showed the plumpness of female E. sinensis was higher than that of male ones from Sept to Dec and the highest plumpness of male and female E. sinensis reached 99,436.44 and 109,207.15mm 3 in Oct. The normalized lipid volume of live male and female E. sinensis had a positive correlation with lipid content. This proposed method with short assay time, favorable selectivity, and accuracy demonstrated its application potential in grading regulation and quality evaluation of live E. sinensis. Copyright © 2017. Published by Elsevier Ltd.

  3. Non-destructive determination of moisture content and micro-fibril angle of wood using a poly-chromatic X-ray beam theoretical and experimental approach

    International Nuclear Information System (INIS)

    Baettig, R.

    2005-07-01

    Non-destructive determination of moisture content and micro-fibril angle are important stakes for the sciences of the wood because these two parameters influence strongly the macroscopic behavior of the wood. For example, the shrinkage, the mechanical properties, the thermal and acoustic conductivity are dependent on the moisture content and their anisotropic character is largely governed by the micro-fibril angle. We used the light difference between X-ray mass attenuation coefficient for the water and for the wood in transmission. Regrettably, the results show that this difference between X-ray mass attenuation coefficient is insufficient to allow the precise measurement of the moisture content.In spite of this, the coherent scattering shows sensitive effects. So, by using a poly-energetic beam and a spectrometric system, we were able to discriminate between the crystalline constituent (cellulose) of the amorphous constituent (water) in a sample of wet wood, because for a given angle these phases scatter in different energy. Besides, the device created allowed us to study the crystalline phase of the wood. We were able to confront experimental profiles of diffraction with theoretical profiles of diffraction, obtained by means of a rigorous simulation, in the objective to estimate the average micro-fibril angle and its standard deviation. (author)

  4. Development of fluorescent, oscillometric and photometric methods to determine absorbed dose in irradiated fruits and nuts

    International Nuclear Information System (INIS)

    Kovacs, A.; Foeldiak, G.; Hargittai, P.; Miller, S.D.

    2001-01-01

    To ensure suitable quality control at food irradiation technologies and for quarantine authorities, simple routine dosimetry methods are needed for absorbed dose control. Taking into account the requirements at quarantine locations these methods would require nondestructive analysis for repeated measurements. Different dosimetry systems with different analytical evaluation methods have been tested and/or developed for absorbed dose measurements in the dose range of 0.1-10 kGy. In order to use the well accepted ethanolmonochlorobenzene dosimeter solution and the recently developed aqueous alanine solution in small volume sealed vials, a new portable, digital, and programmable oscillometric reader was developed. To make use of the availability of the very sensitive fluorimetric evaluation method, liquid and solid inorganic and organic dosimetry systems were developed for dose control using a new routine, portable, and computer controlled fluorimeter. Absorption or transmission photometric methods were also applied for dose measurements of solid or liquid phase dosimeter systems containing radiochromic dye agents, which change colour upon irradiation. (author)

  5. Determination of surface dose rate for cloisonne using thermoluminescent dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Hengyuan, Zhao; Yulian, Zhang

    1985-07-01

    In this paper, the measuring method and results of surface dose rate of cloisonne using CaSO/sub 4/ Dy-Teflon foil dosimeter are described. The surface dose rate of all products are below 0.015 mrad/h. These products contain 42 sorts of jewelery and 20 sets of wares (such as vases, plates, ash-trays, etc.). Most of the data fall within the range of natural background. For comparison, some jewelery from Taiwan and 3 vases from Japan are measured. The highest surface dose rate of 0.78 mrad/h is due to the necklace jewelery from Taiwan.

  6. Dose determination by ESR in an accident, using cotton fabric

    International Nuclear Information System (INIS)

    Venkataramani, R.; Mehta, S.K.; Iyer, M.R.; Natarajan, V.; Sastry, M.D.

    1993-01-01

    Accidental exposure dose assessment by electron spin resonance (ESR) technique from the free radicals generated in a cotton handkerchief has been attempted in this investigation. The cotton handkerchief, a common material carried by individuals, was taken as the medium for free radical estimation. About 55 mg of the irradiated piece of cloth was loaded into a quartz tube and the dose dependence of the ESR signal at g = 2.0026 was measured at room temperature, using a Bruker ESP-300 ESR spectrometer in X-band (9.74 GHz). The intensity of this signal was found to be proportional to the dose in the range of 1-1000 Gy. The stability of the free radicals with time of storage was followed. Dependence of dose rate as well as the presence of water on the yield of free radicals were also investigated. (author) 5 refs.; 4 figs.; 2 tabs

  7. Natural dose level determination at Johor State with thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    Ahmad Termizi Ramli; Yusof Jasman

    1995-01-01

    This paperwork presented the results of using thermoluminescence dosimetry (TLD) method in measuring background dose level, which is done at State of Johor, South Malaysia. The problems faced also discussed

  8. Non-destructive technique for determining the viability of soybean (Glycine max) seeds using FT-NIR spectroscopy.

    Science.gov (United States)

    Kusumaningrum, Dewi; Lee, Hoonsoo; Lohumi, Santosh; Mo, Changyeun; Kim, Moon S; Cho, Byoung-Kwan

    2018-03-01

    The viability of seeds is important for determining their quality. A high-quality seed is one that has a high capability of germination that is necessary to ensure high productivity. Hence, developing technology for the detection of seed viability is a high priority in agriculture. Fourier transform near-infrared (FT-NIR) spectroscopy is one of the most popular devices among other vibrational spectroscopies. This study aims to use FT-NIR spectroscopy to determine the viability of soybean seeds. Viable and artificial ageing seeds as non-viable soybeans were used in this research. The FT-NIR spectra of soybean seeds were collected and analysed using a partial least-squares discriminant analysis (PLS-DA) to classify viable and non-viable soybean seeds. Moreover, the variable importance in projection (VIP) method for variable selection combined with the PLS-DA was employed. The most effective wavelengths were selected by the VIP method, which selected 146 optimal variables from the full set of 1557 variables. The results demonstrated that the FT-NIR spectral analysis with the PLS-DA method that uses all variables or the selected variables showed good performance based on the high value of prediction accuracy for soybean viability with an accuracy close to 100%. Hence, FT-NIR techniques with a chemometric analysis have the potential for rapidly measuring soybean seed viability. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Determination of organ doses during radiological examinations and calculation of somatically significant dose

    International Nuclear Information System (INIS)

    Steiner, H.

    1980-01-01

    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) may well be in need of modification; nevertheless the numerical estimation of SSD arrived at here appears to reflect the right order of magnitude for the estimation of somatic risk. The consideration of the threshold dose for somatic injury remains a problem. (orig./MG) [de

  10. Determination of biomass of mango (Mangifera indica L.) trees by non-destructive method using principle of isotope dilution

    International Nuclear Information System (INIS)

    Kotur, S.C.; Keshava Murthy, S.V.

    2003-01-01

    Biomass of 4-year old trees alphonso mango was estimated by injecting of carrier-free 32 P into the trunk followed by radio-assay of the isotope after a complete dilution of 32 P in the tree, being 3 months after injection. The isotopically calculated plant volume (59 903-68 981 cc plant -1 ) and biomass (31.70 - 36.23 kg plant -1 ) showed good agreement but generally overestimated both by about 23% compared to the actual values determined physically (43 720-60 693 cc plant -1 and 22.88-34.78 kg plant -1 , respectively). Application of the technique in a set of another four 15-year old mango trees yielded volume estimates of 1, 70, 749-1 75 835 cc plant -1 (mean=1, 75 835±1.12%) and biomass estimates of 73.0 - 87.4 kg plant -1 (mean=80.45±6.8%). The technique is of promise in fertilizer use efficiency and nutrient dynamics studies in tree crops. (author)

  11. Determination of dose factors for external gamma radiation in dwellings

    International Nuclear Information System (INIS)

    Maduar, M.F.; Hiromoto, G.

    2000-01-01

    A significant contribution to the global population exposure to ionizing radiation arises from natural sources, especially from radionuclides present in terrestrial crust. Human activities can eventually increase that exposure to significant levels, from the point of view of radiological protection. The presence of natural radionuclides in building materials may lead to an increment of both external and internal radiation exposure of the population. External exposure in dwellings arises from gamma-emitter radionuclides existing in the walls, floor and ceiling of their rooms. Mathematical models can be used to predict external dose rates inside the room, known the radionuclide concentration activities in dwelling constituents. This paper presents a methodology for theoretical evaluation of external gamma doses due to radionuclides present in the walls of an hypothetical standard room. The room is modeled as three pairs of rectangular sheets with finite thickness. Assessment of doses was performed through the application of photon transport model, taking in account self-absorption and radiation buildup. As the external dose due to a particular radionuclide is proportional to its activity concentration, results are presented as dose factors, defined as a ratio of absorbed dose (nGy.h -1 ) to the activity concentration (Bq.kg -1 ), for each radionuclide. The radionuclides were assumed to be uniformly distributed in the building materials. Calculations were performed for concrete walls and results are presented for 40 K, 226 Ra, and 232 Th, taking in account, for dose calculations, all gamma emitters from 226 Ra and 232 Th decay chains. Sensitivity of the model was estimated by varying four of its input parameters within a reasonable range of applicability, while leaving all other parameters at fixed selected values. The parameters studied and respective ranges of variation were: for thickness, 5 to 60 cm; for density, 0.5 to 4 g.cm -3 ; for the room length, 1.5 to 10 m

  12. Determination of dose rates from natural radionuclides in dental materials

    International Nuclear Information System (INIS)

    Veronese, I.; Guzzi, G.; Giussani, A.; Cantone, M.C.; Ripamonti, D.

    2006-01-01

    Different types of materials used for dental prosthetics restoration, including feldspathic ceramics, glass ceramics, zirconia-based ceramics, alumina-based ceramics, and resin-based materials, were investigated with regard to content of natural radionuclides by means of thermoluminescence beta dosimetry and gamma spectrometry. The gross beta dose rate from feldspathic and glass ceramics was about ten times higher than the background measurement, whereas resin-based materials generated negligible beta dose rate, similarly to natural tooth samples. The specific activity of uranium and thorium was significantly below the levels found in the period when addition of uranium to dental porcelain materials was still permitted. The high-beta dose levels observed in feldspathic porcelains and glass ceramics are thus mainly ascribable to 4 K, naturally present in these specimens. Although the measured values are below the recommended limits, results indicate that patients with prostheses are subject to higher dose levels than other members of the population. Alumina- and zirconia-based ceramics might be a promising alternative, as they have generally lower beta dose rates than the conventional porcelain materials. However, the dosimetry results, which imply the presence of inhomogeneously distributed clusters of radionuclides in the sample matrix, and the still unsuitable structural properties call for further optimization of these materials

  13. Determining plutonium mass in spent fuel with non-destructive assay techniques - NGSU research overview and update on 6 NDA techniques

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, Stephen J [Los Alamos National Laboratory; Conlin, Jeremy L [Los Alamos National Laboratory; Evans, Louise G [Los Alamos National Laboratory; Hu, Jianwei [Los Alamos National Laboratory; Blanc, Pauline C [Los Alamos National Laboratory; Lafleur, Adrienne M [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Schear, Melissa A [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Fensin, Michael L [Los Alamos National Laboratory; Freeman, Corey R [Los Alamos National Laboratory; Koehler, William E [Los Alamos National Laboratory; Mozin, V [Los Alamos National Laboratory; Sandoval, N P [Los Alamos National Laboratory; Lee, T H [KAERI; Cambell, L W [PNNL; Cheatham, J R [ORNL; Gesh, C J [PNNL; Hunt, A [IDAHO STATE UNIV; Ludewigt, B A [LBNL; Smith, L E [PNNL; Sterbentz, J [INL

    2010-09-15

    This poster is one of two complementary posters. The Next Generation Safeguards Initiative (NGSI) of the U.S. DOE has initiated a multi-lab/university collaboration to quantify the plutonium (Pu) mass in, and detect the diversion of pins from, spent nuclear fuel assemblies with non-destructive assay (NDA). This research effort has the goal of quantifying the capability of 14 NDA techniques as well as training a future generation of safeguards practitioners. By November of 2010, we will be 1.5 years into the first phase (2.5 years) of work. This first phase involves primarily Monte Carlo modelling while the second phase (also 2.5 years) will focus on experimental work. The goal of phase one is to quantify the detection capability of the various techniques for the benefit of safeguard technology developers, regulators, and policy makers as well as to determine what integrated techniques merit experimental work, We are considering a wide range of possible technologies since our research horizon is longer term than the focus of most regulator bodies. The capability of all of the NDA techniques will be determined for a library of 64 17 x 17 PWR assemblies [burnups (15, 30, 45, 60 GWd/tU), initial enrichments (2, 3, 4, 5%) and cooling times (1, 5, 20, 80 years)]. The burnup and cooling time were simulated with each fuel pin being comprised of four radial regions. In this paper an overview of the purpose will be given as well as a technical update on the following 6 neutron techniques: {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Passive Neutron Albedo Reactivity, Self-Integration Neutron Resonance Densitometry. The technical update will quantify the anticipated performance of each technique for the 64 assemblies of the spent fuel library.

  14. Determining plutonium mass in spent fuel with non-destructive assay techniques - NGSI research overview and update on 6 NDA techniques

    International Nuclear Information System (INIS)

    Tobin, Stephen J.; Conlin, Jeremy L.; Evans, Louise G.; Hu, Kianwei; Blanc, P.C.; Lafleur, Am; Menlove, H.O.; Schear, M.A.; Swinhoe, M.T.; Croft, S.; Fensin, M.L.; Freeman, C.R.; Koehler, W.E.; Mozin, V.; Sandoval, N.P.; Lee, T.H.; Cambell, L.W.; Cheatham, J.R.; Gesh, C.J.; Hunt, A.; Ludewigt, B.A.; Smith, L.E.; Sterbentz, J.

    2010-01-01

    This poster is one of two complementary posters. The Next Generation Safeguards Initiative (NGSI) of the U.S. DOE has initiated a multi-lab/university collaboration to quantify the plutonium (Pu) mass in, and detect the diversion of pins from, spent nuclear fuel assemblies with non-destructive assay (NDA). This research effort has the goal of quantifying the capability of 14 NDA techniques as well as training a future generation of safeguards practitioners. By November of 2010, we will be 1.5 years into the first phase (2.5 years) of work. This first phase involves primarily Monte Carlo modelling while the second phase (also 2.5 years) will focus on experimental work. The goal of phase one is to quantify the detection capability of the various techniques for the benefit of safeguard technology developers, regulators, and policy makers as well as to determine what integrated techniques merit experimental work, We are considering a wide range of possible technologies since our research horizon is longer term than the focus of most regulator bodies. The capability of all of the NDA techniques will be determined for a library of 64 17 x 17 PWR assemblies (burnups (15, 30, 45, 60 GWd/tU), initial enrichments (2, 3, 4, 5%) and cooling times (1, 5, 20, 80 years)). The burnup and cooling time were simulated with each fuel pin being comprised of four radial regions. In this paper an overview of the purpose will be given as well as a technical update on the following 6 neutron techniques: 252 Cf Interrogation with Prompt Neutron Detection, Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Passive Neutron Albedo Reactivity, Self-Integration Neutron Resonance Densitometry. The technical update will quantify the anticipated performance of each technique for the 64 assemblies of the spent fuel library.

  15. Determinants to dose reduction in EMCCR - in regulatory perspective

    International Nuclear Information System (INIS)

    Mohan, V.; Venkataraman, S.; Venkataraman, R.; Sajeev, B.S.

    2006-01-01

    Indian PHWRs had experienced three en masse coolant channel replacement campaigns, (EMCCR) first in RAPS-2, next in MAPS-2 and the last in MAPS-1. The campaign is already in full swing at NAPS-1. At MAPS, two EMCCR campaigns were done in a span of four years. The collective dose consumption in the MAPS-1 campaign was only about 25 % that of MAPS-2, a commendable achievement. Based on the experience of RAPS-2 and MAPS-2 campaigns, AERB - through several regulatory means- had given directives for reduction in collective dose in MAPS-1 campaign which was successfully implemented. This paper analyses and quantifies the key factors that contributed to collective dose reduction in MAPS-1 EMCCR. These factors could be put to use in the on going NAPS and forthcoming KAPS campaigns. (author)

  16. Determination of 239Pu and 240Pu isotope ratio for a nuclear bomb particle using X-ray spectrometry in conjunction with γ-ray spectrometry and non-destructive α-particle spectrometry

    International Nuclear Information System (INIS)

    Poellaenen, R.; Ruotsalainen, K.; Toivonen, H.

    2009-01-01

    A nuclear bomb particle from Thule containing Pu and U was analyzed using X-ray spectrometry in combination with γ-ray spectrometry and non-destructive α-spectrometry. The main objective was to investigate the possibility to determine the 239 Pu and 240 Pu isotope ratios. Previously, X-ray spectrometry together with the above-mentioned methods has been successfully applied for radiochemically processed samples, but not for individual particles. In the present paper we demonstrate the power of non-destructive analysis. The 239 Pu/( 239 Pu+ 240 Pu) atom ratio for the Thule particle was determined, using two different approaches, to be 0.93±0.07 and 0.91±0.05. These results are consistent with weapons-grade material and the results obtained by other investigators.

  17. Determination of the absorbed dose and dose-distribution in water for low- and medium-energetic photons

    International Nuclear Information System (INIS)

    Bultman, J.H.

    1990-05-01

    The methods to determine the absorbed dose to water for low and medium energy photons were studied. Large differences between the results of these methods exists. So, a research proposition has been made to explain these differences. The goal of this research will be the development of a method to determine the absorbed dose below approximately 400 keV with an ionization chamber calibrated at 60 Co gamma radiation. To explain the differences between the set of methods, some causes were proposed, like the influence of the ionisation chamber on the measurement in water. Also, some methods to determine the factors are proposed. (author). 29 refs

  18. Determination of the equivalent of environmental dose, H*(d), in a radiotherapy installation

    International Nuclear Information System (INIS)

    Lima, M.A.F.; Borges, J.C.; Mota, H.C.

    1998-01-01

    In order to put into practice radiological protection has been required conversion factors for environmental dose equivalent determination to air kerma value for different kinds of photon and electron beams, such dose values have been determined in a spheric phantom of 30 cm diameter in a alignment field and expanded in a depth of this sphere. Details will be given for determining of equivalent dose distribution calculation using Monte Carlo computational method (ESG4) following the recommendations of ICRU. (Author)

  19. Effects of 14-day oral low dose selenium nanoparticles and selenite in rat—as determined by metabolite pattern determination

    DEFF Research Database (Denmark)

    Hadrup, Niels; Löschner, Katrin; Skov, Kasper

    2016-01-01

    Selenium (Se) is an essential element with a small difference between physiological and toxic doses. To provide more effective and safe Se dosing regimens, as compared to dosing with ionic selenium, nanoparticle formulations have been developed. However, due to the nano-formulation, unexpected...... toxic effects may occur. We used metabolite pattern determination in urine to investigate biological and/or toxic effects in rats administered nanoparticles and for comparison included ionic selenium at an equimolar dose in the form of sodium selenite. Low doses of 10 and 100 fold the recommended human...

  20. Effect of soil contamination due to wastewater irrigation on total cesium as determined by destructive and nondestructive analytical techniques in some soils of egypt

    International Nuclear Information System (INIS)

    Abdel-Sabour, M.F.; Abdel-Lattif, A.

    2005-01-01

    Fifteen soil samples were chosen from different locations to represent different soils irrigated with different sources of contaminated wastewater (sewage and industrial effluent). Sequential extraction experiment was carried out to determine different forms of Cs in soils. Moreover, Soil samples were analyzed for total Cs using two analytical methods i.e. destructive wet digestion technique (Atomic Absorption Spectrometry, AAS or by summation of all sequential extracted fractions, SUM) and non-destructive technique (Neutron Activation Analysis, NAA). The aim of this study was to evaluate soil total Cs-forms (especially, bio-available fraction) as affected by soil pollution. Cesium was mostly concentrated in the residual fraction, and its values ranged from 57.4% to 82.9 % of total Cs in sandy soils and from 31.5% to 64.5 % of total Cs in tested clayey soil. Then organically bound Cs- fraction followed by Cs-occluded in Fe-Mn fraction, carbonate, exchangeable and water soluble fractions. Results suggested that, Cs level is affected by soil organic matter content, Fe-Mn oxides and clay content. The mobile Cs fraction (the sum of soluble and exchangeable fractions) ranged from 2% up to 9.9 % of total Cs in sandy soils. However, a higher value (9.82% to 15.31 %) could be observed in case of the tested clayey soils. Soils D and E were more contaminated than other tested soils. Data show obviously, that soil contaminated due to the irrigation with either sewage effluent or industrial wastewater has resulted in a drastic increase in both metal-organic and occluded in Fe and Mn oxide fractions followed by the carbonate fraction

  1. Dose calculation and isodose curves determination in brachytherapy

    International Nuclear Information System (INIS)

    Maranhao, Frederico B.; Lima, Fernando R.A.; Khoury, Helen J.

    2000-01-01

    Brachytherapy is a form of cancer treatment in which small radioactive sources are placed inside of, or close to small tumors, in order to cause tissue necrosis and, consequently, to interrupt the tumor growth process. A very important aspect to the planning of this therapy is the calculation of dose distributions in the tumor and nearby tissues, to avoid the unnecessary irradiation of healthy tissue. The objective of this work is to develop a computer program that will permit treatment planning for brachytherapy at low dose rates, minimizing the possible errors introduced when such calculations are done manually. Results obtained showed good agreement with those from programs such as BRA, which is widely used in medical practice. (author)

  2. Determination of dose equivalent and risk in thorium cycle

    International Nuclear Information System (INIS)

    Ney, C.L.V.N.

    1988-01-01

    In these report are presented the calculations of dose equivalent and risk, utilizing the dosimetric model described in publication 30 of the International Comission on Radiological Protection. This information was obtained by the workers of the thorium cycle, employed at the Praia and Santo Amaro Facilities, by assessing the quantity and concentration of thorium in the air. The samples and the number of measurements were established through design of experiments techniques, and the results were evaluated with the aid of variance analysis. The estimater of dose equivalent for internal and external radiation exposure and risk associated were compared with the maximum recommended limits. The results indicate the existence of operation areas whose values were above those limits, requiring so an improvement in the procedures and services in order to meet the requirements of the radiological protetion. (author) [pt

  3. Phototransfer method of determining archaeological dose of pottery sherds

    International Nuclear Information System (INIS)

    Sasidharan, R.; Sunta, C.M.; Nambi, K.S.V.

    1978-01-01

    The method of PTTL (phototransfer thermoluminescence) dating works satisfactorily over a very wide range of archaeological doses and the upper limit seems to be around 4000 rads. The first TL peak generally occurs at 65deg C or 100deg C in different varieties of quartz and both seem to be satisfactory for PTTL dating if the reading procedure is standardised to take care of the fast fading of these peaks at room temperature. (author)

  4. European conference on nondestructive testing

    Energy Technology Data Exchange (ETDEWEB)

    Klyuev, V V

    1985-01-01

    Information on the 3-d European conference on nondestructive testing (NT) held in October, 1984 in Florence, is presented. Plenary reports were devoted to complex use of different NT methods, tendencies to NT automation and robotics, transition from defectoscopy to quality control, determination of phisico-mechanical properties of items using different control methods, formulation of unified international programs on professional training and qualification. Section reports cover the following directions: NT use in aviation and astronautics, construction, welding engineering, studying works of art; personnel training, economics, NT functioning, automation, calibration, standardization, quality control over metallic and nonmetallic objects. Some reports concerned nondestructive testing of items during their use. Attention is paied to radiographic testing and neutron radiography as well as to image processing. NT equipment was also discussed.

  5. Quality control procedure of the BNCT patient dose determination

    International Nuclear Information System (INIS)

    Bjugg, H.; Kortesniemi, M.; Seppaelae, T.; Karila, J.; Perkioe, J.; Ryynaenen, P.; Savolainen, S.; Auterinen, I.; Kotiluoto, P.; Seren, T.

    2000-01-01

    The concepts used at the Finnish BNCT facility for the patient dose quality assurance are introduced here. Dose planning images are obtained using a MR scanner with MRI sensitive markers. The dose distribution is computed with BNCT Rtpe. The program and the beam (DORT) model used have been verified with measurements and validated with MCNP calculations in phantoms. Dosimetric intercomparison has been done between FiR 1 and BMRR BNCT beams. The FiR 1 beam has been characterised also by visiting teams. Before every patient irradiation the relationship between beam monitor pulse rate and neutron fluence rate in the beam is checked by activation measurements. Cross-hair lasers used in the patient positioning are checked for spatial drift prior to each treatment. Kinetic models used to estimate the time-behaviour of blood boron concentration have been verified using independent patient sample data to assess and verify the performance of the applications. Quality control guides have been developed for each step in the patient irradiation. (author)

  6. Determination of the Absorbed Doses in Shanks of Interventional Radiologists

    International Nuclear Information System (INIS)

    Golnik, N.; Szczepanski, K.; Tulik, P.; Obryk, B.

    2008-01-01

    Complicated procedures of interventional radiology require usually a much longer investigation time, comparing to the conventional radiography. Moreover, interventional radiology procedures require the presence of the medical staff next to the patient in order to perform the procedure. This results in higher risk for health professionals. Even though these persons reasonably keep away from the primary X ray beam, they are under the effects of scatter radiation due to the interaction of the primary beam with the patient. The protection aprons, thyroid protectors and shielding glasses are used in order to minimize the doses for the staff, but lower parts of legs remain usually unprotected and the absorbed doses in shanks are not recorded. The paper presents the measured values of the absorbed dose in lower extremities of medical staff, involved in the procedures of interventional radiology, completed with the measurements of air kerma under the patient table. Measurements were performed in one of big hospitals in Warsaw during all the procedures performed in six weeks. Majority of the procedures constituted angioplasty or angioplasty with vascular stenting, uterine fibroid embolization and cholangiography. In the angioplasty procedure, imaging techniques are used to guide a balloon-tipped catheter into an artery and advance it to where the vessel is narrow or blocked. The balloon is then inflated to open the vessel, deflated and removed. In vascular stenting, which is often performed with angioplasty, a small wire mesh tube (a stent) is permanently placed in the newly opened artery to help it remain open. In a uterine fibroid embolization procedure, the image guidance is used in order to place an embolic agent (synthetic material) inside one or more of the blood vessels that supply the fibroid tumors with blood. As a result, these vessels become occluded, or closed off, and the fibroid tissue shrinks. Percutaneous transhepatic cholangiography is a way of examining

  7. Quantifying the passive gamma signal from spent nuclear fuel in support of determining the plutonium content in spent nuclear fuel with nondestructive assay

    Energy Technology Data Exchange (ETDEWEB)

    Fensin, Michael L [Los Alamos National Laboratory; Tobin, Steven J [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory

    2009-01-01

    The objective of safeguarding nuclear material is to deter diversions of significant quantities of nuclear materials by timely monitoring and detection. There are a variety of motivations for quantifying plutonium in spent fuel (SF), by means of nondestructive assay (NDA), in order to meet this goal. These motivations include the following: strengthening the capabilities of the International Atomic Energy Agencies ability to safeguard nuclear facilities, shipper/receiver difference, input accountability at reprocessing facilities and burnup credit at repositories. Many NDA techniques exist for measuring signatures from SF; however, no single NDA technique can, in isolation, quantify elemental plutonium in SF. A study has been undertaken to determine the best integrated combination of 13 NDA techniques for characterizing Pu mass in spent fuel. This paper focuses on the development of a passive gamma measurement system in support the spent fuel assay system. Gamma ray detection for fresh nuclear fuel focuses on gamma ray emissions that directly coincide with the actinides of interest to the assay. For example, the 186-keV gamma ray is generally used for {sup 235}U assay and the 384-keV complex is generally used for assaying plutonium. In spent nuclear fuel, these signatures cannot be detected as the Compton continuum created from the fission products dominates the signal in this energy range. For SF, the measured gamma signatures from key fission products ({sup 134}Cs, {sup 137}Cs, {sup 154}Eu) are used to ascertain burnup, cooling time, and fissile content information. In this paper the Monte Carlo modeling set-up for a passive gamma spent fuel assay system will be described. The set-up of the system includes a germanium detector and an ion chamber and will be used to gain passive gamma information that will be integrated into a system for determining Pu in SF. The passive gamma signal will be determined from a library of {approx} 100 assemblies that have been

  8. Nondestructive testing 89

    International Nuclear Information System (INIS)

    1989-01-01

    The proceedings contain 24 contributions, out of which 14 have been inputted in INIS. These deal with materials for nondestructive testing and various nondestructive testing systems, with the evaluation of radiograms and with the application of radiographic, ultrasonic and eddy current methods to the detection of defects in materials, to the inspection of nuclear reactor components and in other fields of technology. (B.S.)

  9. Nondestructive testing of materials

    International Nuclear Information System (INIS)

    NUKEM has transferred know-how from reactor technology to materials testing. The high and to a large extent new quality standards in the nuclear industry necessitate reliable measuring and testing equipment of the highest precision. Many of the tasks presented to us could not be solved with the equipment available on the market, for which reason we have developed our own measuring, testing and control systems. We have therefore acquired considerable experience in dealing with specific measuring, testing and control tasks and can handle even out-of-the-way problems that are submitted to us from a wide variety of fields. Our mechanical systems for the checking of close-tolerance gaps, the automatic determination of pellet dimensions and the measurement of absolute lengths and absolute velocities are in use in many different industrial fields. We have succeeded in solving unusual testing and sorting problems with the aid of automated surface testing equipment working on optical principles. Our main activities in the field of non-destructive testing have been concentrated on ultrasonic and eddy current testing and, of late, acoustic emission analysis. NUKEM ultrasonic systems are notable for their high defect detection rate and testing accuracy, combined with high testing speed. The equipment we supply includes ultrasonic rotary systems for the production testing of quality tubes, ultrasonic immersion systems for the final testing of reactor cladding tubes, weld testing equipment, and test equipment for the bonds in multi-layer plates. (orig./RW) [de

  10. Determination of skin dose reduction by lead equivalent gloves

    International Nuclear Information System (INIS)

    Norriza Mohd Isa; Abd Aziz Mhd Ramli

    2006-01-01

    Radiation protective gloves are always used in medical facilities to protect radiation workers from unnecessary radiation exposure. A study on radiation protection gloves which are produced by local company had been performed by the Medical Physics Group, MINT. The gloves were made of lead equivalent material, as the attenuating element. The gloves were evaluated in term of the percentage of skin dose reduction by using a newly developed procedure and facilities in MINT. Attenuation measurements of the gloves had been carried out using direct beams and scattered radiations of different qualities. TLD rings were fitted on finger phantom; and water phantom were used in the measurement. The result were obtained and analysed based on data supplied by manufacturer. (Author)

  11. Effects of 14-day oral low dose selenium nanoparticles and selenite in rat—as determined by metabolite pattern determination

    Directory of Open Access Journals (Sweden)

    Niels Hadrup

    2016-10-01

    Full Text Available Selenium (Se is an essential element with a small difference between physiological and toxic doses. To provide more effective and safe Se dosing regimens, as compared to dosing with ionic selenium, nanoparticle formulations have been developed. However, due to the nano-formulation, unexpected toxic effects may occur. We used metabolite pattern determination in urine to investigate biological and/or toxic effects in rats administered nanoparticles and for comparison included ionic selenium at an equimolar dose in the form of sodium selenite. Low doses of 10 and 100 fold the recommended human high level were employed to study the effects at borderline toxicity. Evaluations of all significantly changed putative metabolites, showed that Se nanoparticles and sodium selenite induced similar dose dependent changes of the metabolite pattern. Putative identified metabolites included increased decenedioic acid and hydroxydecanedioic acid for both Se formulations whereas dipeptides were only increased for selenite. These effects could reflect altered fatty acid and protein metabolism, respectively.

  12. Potential of multispectral imaging technology for rapid and non-destructive determination of the microbiological quality of beef filets during aerobic storage

    DEFF Research Database (Denmark)

    Panagou, Efstathios Z.; Papadopoulou, Olga; Carstensen, Jens Michael

    2014-01-01

    counts, namely Class 1 (TVC7.0log10CFU/g). Furthermore, PLS regression models were developed to provide quantitative estimations of microbial counts during meat storage. In both cases model validation was implemented with independent experiments at intermediate storage temperatures (2 and 10°C) using....... thermosphacta, and TVC, respectively. The results indicated that multispectral vision technology has significant potential as a rapid and non-destructive technique in assessing the microbiological quality of beef fillets....

  13. The determination of the penetrating radiation dose at Hanford

    International Nuclear Information System (INIS)

    Rathbun, L.A.

    1989-09-01

    Most of the thermoluminescent dosimeters (TLDs) and other devices that have been used to measure environmental radiation on the Hanford Site have measured natural background levels of radiation. Measurements of offsite environmental radiation near the boundary of the Hanford Site have often indicated higher doses than onsite measurements have. However, the converse has been found when radiation measurements from the cities and communities of southeastern Washington were compared with onsite measurements. The historical trends described for environmental TLD data have been better defined in this study by compiling the TLD data for selected locations over a 6-year period (1983 to 1988). The ongoing Hanford Environmental Surveillance Program also provides radionuclide concentrations in soil based on samples collected by technicians at Pacific Northwest Laboratory (PNL) and sent to a commercial laboratory for analyses. As part of the study described in this report, a portable gamma spectroscopy system was used in the field to identify concentrations of gamma-emitting radionuclides in the soil at various locations on the Hanford Site and in the surrounding area. This work began in 1986. Supplemental radiation measurements were made with a microprocessor-based survey meter and large NaI detector. 20 refs., 4 figs., 3 tabs

  14. Contributions of non-destructive testing for determining the provenance of the granites used in the Roman Amphitheatre from Emerita Augusta, Badajoz, Spain.

    Science.gov (United States)

    Mota, M. Isabel; Alvarez de Buergo, Monica; Fort, Rafael; Pizzo, Antonio

    2015-04-01

    The Archaeological Ensemble of Emérita Augusta (Mérida, Badajoz, Spain) was listed a World Heritage Site in 1993 by UNESCO. One of the monuments that belongs to this Archaeological Ensemble is the Roman amphitheatre, mainly built with granite from quarries located near the city. Every urban centre in the Roman Empire, in addition to many rural sites, had one or more local quarries from which they extracted the bulk of their stone. In Mérida, there are a group of documented quarries located near the ancient city. In this work the authors have been investigating five of these documented outcrops which, due the distance from the monument or the existence of ancient Roman routes of communication with the city, can be the possible original quarries. The provenance of these materials with which the monument is built is of significant interest in terms of the restoration and conservation and from a historical point of view of the monument. Nowadays, there are many examples of identification of the original quarries that use destructive procedures and techniques which are based on the physical, petrographical, geochemical, magnetic or mechanical properties that are a function of the mineralogical and textural characteristics of the rock. In this work, the combined use of two non-destructive and on-site techniques, ultrasonic velocity and surface hardness determined with a Schmidt hammer rebound tester, allows to determine first, the quality and degree of decay in the granites, usually affecting the material surface and consisting of a decline in surface cohesion, and second, it can discriminate possible provenance areas of the rock used in the building. These two techniques are very useful for this purpose for several reasons. Their combined use allows the selection of the most representative blocks and ashlars for sampling. This reduces sampling to a minimum showing representative results for the whole building, especially in the case of performing ageing tests in the

  15. Dose determination with nitro blue tetrazolium containing radiochromic dye films by measuring absorbed and reflected light

    DEFF Research Database (Denmark)

    Kovács, A.; Baranyai, M.; Wojnárovits, L.

    2000-01-01

    determination in a wide dose range both by absorbance and reflectance measurements. The concept of measuring reflected light from dose labels has been discussed earlier and emerged recently due to the requirement of introducing semiquantitative label dose indicators for quarantine control. The usefulness...... of the method was studied using the newly developed radiochromic dye films as well as already existing ones. (C) 2000 Elsevier Science Ltd. All rights reserved....

  16. Non-Destructive Testing for Concrete Structure

    International Nuclear Information System (INIS)

    Tengku Sarah Tengku Amran; Noor Azreen Masenwat; Mohamad Pauzi Ismail

    2015-01-01

    Nondestructive testing (NDT) is a technique to determine the integrity of a material, component or structure. It is essential in the inspection of alteration, repair and new construction in the building industry. There are a number of non-destructive testing techniques that can be applied to determine the integrity of concrete in a completed structure. Each has its own advantages and limitations. For concrete, these problems relate to strength, cracking, dimensions, delamination, and inhomogeneities. NDT is reasonably good and reliable tool to measure the property of concrete which also gives the fair indication of the compressive strength development. This paper discussed the concrete inspection using combined methods of NDT. (author)

  17. Determination of the dose of traffic in HDR brachytherapy with ALANINE/R PE technique

    International Nuclear Information System (INIS)

    Guzman Calcina, C. S.; Chen, F.; Almeida, A. de; Baffa, O.

    2001-01-01

    It determines, experimentally, the dose of traffic in brachytherapy for High Dose Rate (HDR), using for the first-time the Electronic Paramagnetic Resonance (EPR) technique with alanine detectors. The value obtained is the published next to obtained using lithium fluoride thermoluminescent dosimeters [es

  18. Determination and Analysis of Ar-41 Dose Rate Characteristic at Thermal Column of Kartini Reactor

    International Nuclear Information System (INIS)

    Widarto; Sardjono, Y.

    2007-01-01

    Determination and Analysis of Ar-41 activity dose rate at the thermal column after shutdown of Kartini reactor has been done. Based on evaluation and analysis concluded that external dose rate is D = 1.606x10 -6 Sv/second and internal dose rate is 3.429x10 -1 1 Sv/second. It means that if employee work at the column thermal area for 15 minutes a day, 5 days a week, in a year will be 0.376 Sv still under dose rate limit i.e. 0.5 Sv, so that the column thermal facility is safely area. (author)

  19. Determination of burial dose in incompletely bleached fluvial samples using single grains of quartz

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, Lars

    2007-01-01

    We determine the burial dose in three known-age incompletely bleached fluvial samples using single grains of quartz. Estimation of burial dose in incompletely bleached samples requires that the characteristics of the well-bleached part of the distribution are known in order to distinguish between...... well-bleached and poorly bleached grains. It is especially important to investigate if the uncertainties assigned to individual estimates of dose adequately describe the observed variability in well-bleached dose distributions. We investigate this by quantifying the overdispersion in laboratory-bleached...

  20. Determination and reliability of dose coefficients for radiopharmaceuticals; Ermittlung der Zuverlaessigkeit von Dosiskoeffizienten fuer Radiopharmaka

    Energy Technology Data Exchange (ETDEWEB)

    Spielmann, V.; Li, W.B.; Zankl, M.; Oeh, U.

    2015-11-15

    The dose coefficients used in nuclear medicine for dose calculations of radiopharmaceuticals are based on recommendations by ICRP (International Commission on radiological protection) and the MIRD (Medical Internal Radiation Dose Committee) using mathematical models for the temporal activity distributions in organs and tissues (biokinetic models) and mathematical models of the human body. These models using an idealized human body do not include uncertainty estimations. The research project is aimed to determine the uncertainties and thus the reliability of the dose coefficients for radiopharmaceuticals and to identify the biokinetic and dosimetric parameters that contribute most of the uncertainties.

  1. Determination of absorbed dose to the lens of eye from external sources

    International Nuclear Information System (INIS)

    Chen Lishu

    1993-01-01

    The methods of determining absorbed dose distributions in human eyeball by means of the experiments and available theories have been reported. A water phantom was built up. The distributions of beta dose were measured by an extrapolation ionization chamber at some depths corresponding to components of human eyeball such as cornea, sclera, anterior chamber and the lens of eye. The ratios among superficial absorbed dose (at 0.07 mm) and average absorbed doses at the depths 1,2,3 mm are obtained. They can be used for confining the deterministic effects of superficial tissues and organs such as the lens of eye for weakly penetrating radiations

  2. Non-destructive micro-X-ray diffraction analysis of painted artefacts: Determination of detection limits for the chromium oxide-zinc oxide matrix

    International Nuclear Information System (INIS)

    Nel, P.; Lau, D.; Hay, D.; Wright, N.

    2006-01-01

    The development of micro-X-ray diffraction (micro-XRD) enables non-destructive, in situ analysis of crystalline pigments on artworks and archaeological objects. Pigments with X-ray diffraction patterns with large peak intensities may complicate the identification of other components with lower absorption coefficients, especially if present in low concentrations in the paint sample. Investigation of this issue involved: (1) micro-XRD examination and analysis of the amorphous and crystalline phases of fifteen pigment films and (2) micro-XRD examination and semi-quantitative analysis of various chromium oxide-zinc oxide mixtures, which established detection limits as low as 5 ± 2%

  3. Determination of dose to patient in different teams of TC and assessment with international reference levels

    International Nuclear Information System (INIS)

    Ruiz Morales, C.; Fernandez lara, A. A.; Buades Forner, M. J.; Tobarra Gonzalez, B. M.

    2013-01-01

    The increase in CT studies and the differences observed between the different equipment used in our hospital prompted us to determine the doses to patients in different studies and check the results obtained with the reference values published internationally. (Author)

  4. Determination of the total indicative dose in drinking and mineral waters

    International Nuclear Information System (INIS)

    Flesch, K.; Schulz, H.; Knappik, R.; Koehler, M.

    2006-01-01

    In Europe and Germany administrative regulations exist for the surveillance of the total indicative dose of water supplied for human consumption. This parameter, which cannot be analyzed directly, has to be calculated using nuclide specific activity concentration and age specific dose conversion factors and consumption rates. Available calculation methods differ regarding the used radionuclides, consumption rates and whether they use age specific dose conversion factors or not. In Germany administrative guidelines for the determination of the total indicative dose are still not available. As they have analyzed a large number of waters in the past, the authors derive a praxis orientated concept for the determination of the total indicative dose which respects radiological, analytical and hydrochemical aspects as well. Finally it is suggested to handle sparkling waters in the same manner as drinking waters. (orig.)

  5. Nondestructive testing method

    International Nuclear Information System (INIS)

    Porter, J.F.

    1996-01-01

    Nondestructive testing (NDT) is the use of physical and chemical methods for evaluating material integrity without impairing its intended usefulness or continuing service. Nondestructive tests are used by manufaturer's for the following reasons: 1) to ensure product reliability; 2) to prevent accidents and save human lives; 3) to aid in better product design; 4) to control manufacturing processes; and 5) to maintain a uniform quality level. Nondestructive testing is used extensively on power plants, oil and chemical refineries, offshore oil rigs and pipeline (NDT can even be conducted underwater), welds on tanks, boilers, pressure vessels and heat exchengers. NDT is now being used for testing concrete and composite materials. Because of the criticality of its application, NDT should be performed and the results evaluated by qualified personnel. There are five basic nondestructive examination methods: 1) liquid penetrant testing - method used for detecting surface flaws in materials. This method can be used for metallic and nonmetallic materials, portable and relatively inexpensive. 2) magnetic particle testing - method used to detect surface and subsurface flaws in ferromagnetic materials; 3) radiographic testing - method used to detect internal flaws and significant variation in material composition and thickness; 4) ultrasonic testing - method used to detect internal and external flaws in materials. This method uses ultrasonics to measure thickness of a material or to examine the internal structure for discontinuities. 5) eddy current testing - method used to detect surface and subsurface flaws in conductive materials. Not one nondestructive examination method can find all discontinuities in all of the materials capable of being tested. The most important consideration is for the specifier of the test to be familiar with the test method and its applicability to the type and geometry of the material and the flaws to be detected

  6. Determination of Absorbed Dose to Water for Leksell Gamma Knife Unit

    International Nuclear Information System (INIS)

    Hrsak, H.

    2013-01-01

    Because of geometry of photon beams in Leksell Gamma Knife Unit (LGK), there are several technical problems in applying standard protocols for determination of absorbed dose to water (Dw). Currently, Dw in LGK unit, measured at the center of spherical plastic phantom, is used for dose calculation in LGK radiosurgery. Treatment planning software (LGP TPS) accepts this value as a measurement in water and since plastic phantom has higher electron density than water, this leads to systematic errors in dose calculation. To reduce these errors, a photon attenuation correction (PAC) method was applied. For that purpose, measurements of absorbed dose in a center of three different plastic phantoms with 16 cm diameter (ABS - acrylonitrile butadiene styrene, PMMA - polymethyl metacrylate, PMMA + teflon - polytetrafluoroethylene 5 mm shell) were made with ionization chamber (Semiflex, PTW Freiburg). For measured dose values, PAC to water was applied based on electron density (ED) and equivalent water depths (EWD) of the plastic phantoms. The relation between CT number and ED was determined by measuring CT number of standard CT to ED phantom (CIRS Model 062 Phantom). Absorbed dose in plastic phantoms was 2.5 % lower than calculated dose in water for ABS phantom and more than 5.5 % lower for PMMA and PMMA+teflon phantom. Calculated dose in water showed more consistent values for all three phantoms (max. difference 2.6 %). EWD for human cranial bones and brain has value close to the EWD of ABS phantom, which makes this phantom most suitable for dose measurements in clinical application. In LGK radiosurgery determination of errors related to the difference of phantom materials should not be neglected and measured dose should be corrected before usage for patient treatment dose calculation.(author)

  7. System for determining absorbed dose and its distribution for high-energy electron radiation

    International Nuclear Information System (INIS)

    Hegewald, H.; Wulff, W.

    1977-01-01

    Taking into account the polarization effect, the dose determination for high-energy electron radiation from particle accelerators depends on the knowledge of the energy dependence of the mass stopping power. Results obtained with thermoluminescent dosemeters agree with theoretical values. For absorbed dose measurements the primary energy of electron radiation has been determined by nuclear photoreactions, and the calculation of the absorbed dose from charge measurements by means of the mass stopping power is described. Thus the calibration of ionization chambers for high-energy electron radiation by absolute measurements with the Faraday cage and chemical dosemeters has become possible. (author)

  8. Determination of dose received by bladder and rectum in external cervical irradiation

    International Nuclear Information System (INIS)

    Omer, Mohamed Ahmed Ali

    2001-12-01

    The cervical carcinoma is the common type of malignant tumor among sudanese females during the last years. The conventional external irradiation therapy is the common model of treatment for cervical carcinoma in (RICK). The irradiation of such cases implemented via four fields (box technique), two anterior and posterior and two lateral opposed fields, as central dose calculation, giving a dose of 5000 c Gy fractionated into 25 to 30 fractions. The parameter of the fields lie at the promontory of the sacral cephalic and at the obturators foramen caudally and laterally at the bony pelvic by one centimeter. The aim of the research is to determine the dose received by the rectum and bladder (critical organs), out of central dose calculation versus off axis dose calculation to (Day's method). The data obtained by using simulator and radiation oncological computerized system (Rocs). The results are analyzed by using statistical processing for social science program (SPSS) that shows the mean dose received by the bladder is 3821 cGy, due to central dose calculation that accompanied by an un-optimum encompassment of treatment line and 4210.6 c Gy. due to Off Axis Dose calculation dose 3324.4 c Gy and 3712.1 c Gy due to central dose calculation. The increment of dose received by the rectum and the bladder is due to utilizing of wider width of the filed size for lateral irradiation. To score the aim of International Atomic Energy Agency (IAEA) and (ALARA) principle A s Low As As Reasonable Available , we have to use the simulator to obtain the anatomical structures on the contour, or will be better to use CT. Scan for calculation of dose at the side of interest. (Author)

  9. Non-destructive controls

    International Nuclear Information System (INIS)

    Nouvet, A.

    1978-01-01

    The non-destructive controls permit, while respecting their integrity, the direct and individual examination of parts or complete objects as they are manufactured, as well as to follow the evolution of their eventual defects while in operation. The choice of control methods depends on the manufacturing process and shapes of parts, on the physical properties of their components as well as the nature, position and size of the defects which are likely to be detected. Whether it is a question of controls by means of ionizing radiation, flux of neutrons, ultrasons, acoustic source, sweating, magnetoscopy. Foucault currents, thermography, detection of leaks or non-destructive metallography, each has a limited field of application such that they are less competitive than complementary [fr

  10. Determination of beta radiation doses received by personnel involved in the mitigation of the Chernobyl accident

    International Nuclear Information System (INIS)

    Osanov, D.P.; Krjuchkov, V.P.; Shaks, A.I.

    1993-01-01

    During the accident at the Chernobyl nuclear power plant on April 26, 1986, and in the post-accident period, workers were exposed to beta and low-energy-photon radiation. This paper describes a method of retrospective estimation of skin doses from these radiations by correlating known doses from gamma radiation. Dose distributions of beta and gamma radiation in tissue-equivalent materials were both calculated and measured using multilayer thermoluminescent dosimeters placed at different site locations. It was determined that the doses to the skin from beta radiation exceeded the maximum doses to the whole-body from gamma radiation by 1 or even 2 orders of magnitude. It is concluded that nuclear power plants should be equipped with multilayer skin dosimeters in order to ensure accurate skin dosimetry. 16 refs., 13 figs., 3 tabs

  11. Light Water Reactor Sustainability (LWRS) Program – Non-Destructive Evaluation (NDE) R&D Roadmap for Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Kevin L.; Ramuhalli, Pradeep; Brenchley, David L.; Coble, Jamie B.; Hashemian, Hash; Konnik, Robert; Ray, Sheila

    2012-09-14

    The purpose of the non-destructive evaluation (NDE) R&D Roadmap for Cables is to support the Materials Aging and Degradation (MAaD) R&D pathway. The focus of the workshop was to identify the technical gaps in detecting aging cables and predicting their remaining life expectancy. The workshop was held in Knoxville, Tennessee, on July 30, 2012, at Analysis and Measurement Services Corporation (AMS) headquarters. The workshop was attended by 30 experts in materials, electrical engineering, U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) National Laboratories (Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and Idaho National Engineering Laboratory), NDE instrumentation development, universities, commercial NDE services and cable manufacturers, and Electric Power Research Institute (EPRI). The motivation for the R&D roadmap comes from the need to address the aging management of in-containment cables at nuclear power plants (NPPs).

  12. Light Water Reactor Sustainability (LWRS) Program – Non-Destructive Evaluation (NDE) R&D Roadmap for Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, K.L.; Ramuhali, P.; Brenchley, D.L.; Coble, J.B.; Hashemian, H.M.; Konnick, R.; Ray, S.

    2012-09-01

    Executive Summary [partial] The purpose of the non-destructive evaluation (NDE) R&D Roadmap for Cables is to support the Materials Aging and Degradation (MAaD) R&D pathway. A workshop was held to gather subject matter experts to develop the NDE R&D Roadmap for Cables. The focus of the workshop was to identify the technical gaps in detecting aging cables and predicting their remaining life expectancy. The workshop was held in Knoxville, Tennessee, on July 30, 2012, at Analysis and Measurement Services Corporation (AMS) headquarters. The workshop was attended by 30 experts in materials, electrical engineering, and NDE instrumentation development from the U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) National Laboratories (Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and Idaho National Engineering Laboratory), universities, commercial NDE service vendors and cable manufacturers, and the Electric Power Research Institute (EPRI).

  13. Nondestructive testing: welding industry

    International Nuclear Information System (INIS)

    Raj, Baldev; Subramanian, C.V.

    1992-01-01

    This chapter highlights various conventional and advanced nondestructive testing (NDT) techniques that have been used for weld evaluation. Welding Codes and Standards of International and National organisations that have been followed in India for various weld evaluation purposes are also included. The chapter also emphasises the importance of NDT by way of a few case studies that have been carried out on important critical welded components. (author). 12 refs., 17 figs., 1 appendix

  14. Dose determination in computed tomography; Determinacion de dosis en tomografia computada

    Energy Technology Data Exchange (ETDEWEB)

    Descamps, C.; Garrigo, E.; Venencia, D. [Fundacion Marie Curie, Instituto Privado de Radioterapia, Departamento de Fisica Medica, Obispo Oro 423, X5000BFI Cordoba (Argentina); Gonzalez, M. [Universidad Nacional de Cordoba, Facultad de Ciencias Exactas, Fisicas y Naturales, Av. Velez Sarsfield 299, Corboba (Argentina); Germanier, A., E-mail: agermani@ceprocor.uncor.edu [Ministerio de Ciencia y Tecnologia, Ceprocor, Alvarez de Arenas 230, X5004AAP Barrio Juniors, Cordoba (Argentina)

    2011-10-15

    In the last years the methodologies to determine the dose in computed tomography have been revised. In this work was realized a dosimetric study about the exploration protocols used for simulation of radiotherapy treatments. The methodology described in the Report No. 111 of the American Association of Medical Physiques on a computed tomograph of two cuts was applied. A cylindrical phantom of water was used with dimensions: 30 cm of diameter and 50 cm of longitude that simulates the absorption and dispersion conditions of a mature body of size average. The doses were determined with ionization chamber and thermoluminescent dosimetry. The results indicate that the dose information that provides the tomograph underestimates the dose between 32 and 35%.

  15. Determination of Doses for X-Ray Examinations of Paranasal Sinuses of Children

    International Nuclear Information System (INIS)

    Milkovic, D.; Miljanic, S.; Knezevic, Z.; Ranogajec-Komor, M.; Beck, N; Zagar, I.

    2013-01-01

    The knowledge of the absorbed doses during X-ray examination is very important, especially in paediatric radiology in order to improve radiation protection. In childhood, the paranasal sinuses diseases are very frequent and the development of sinuses has some specialities which has to be taken into consideration in X-ray diagnostics. The aim of this work was the determination of the relative doses on the thyroid gland and eyes, in respect to the entrance dose on the anthropomorphic child phantom (CIRS). The entrance doses on the phantom to the entrance dose on patients of similar age. Simultaneously the influence of human working method was studied, i.e. the performance of the radiological technicians. The age of the patients varied from 7 to 15 years, the child phantom was equivalent to 10 years age. A protective lead apron on the necks of both children and phantom was used. Doses were measured with radiophotoluminescence (RPL) and thermoluminescence (TL) dosemeters. The mean doses on the thyroid and the eyes measured in the phantom after 10 expositions were 0.20 ± 0.05 mSv, and 0.32 ± 0.02 mSv, respectively. Relative doses were calculated in relation to entrance dose of 9.96 mSv for 10 exposures, and the results were 0.02 and 0.03 for the thyroid gland and the eyes, respectively. The dosimetry results on 45 patients showed that there was a good correlation between measured doses and the body mass index (BMI). The mean entrance dose measured on the 45 patients was 0.97 ± 0.08 mSv.(author)

  16. The determination of effective doses from the intake of tritiated water

    International Nuclear Information System (INIS)

    1987-08-01

    To comply with the regulatory requirements relating to the dose from exposures to tritiated water (HTO), Atomic Energy Control Board (AECB) licensees currently measure tritium concentration in urine to determine whole body dose. This approach has been based on the consideration that the time-integrated tritium concentration (which is proportional to accumulated dose) in any organ from urine concentrations are always conservative. The International Commission on Radiological Protection (ICRP) recommends that the average soft tissue dose be used to determine effective dose equivalents for HTO exposures. The ICRP also recommends that only the retention in body water be considered when committed doses from HTO exposures are calculated; this recommendation is based on the consideration that the errors introduced by neglecting the long-lived tritium component (those tritium atoms retained in organic molecules of the body cells) are small (only of the order of 10% of the committed dose equivalent to the whole body). The AECB position is presented in the following regulatory policy statement

  17. Application of the personnel photographic monitoring method to determine equivalent radiation dose beyond proton accelerator shielding

    International Nuclear Information System (INIS)

    Gel'fand, E.K.; Komochkov, M.M.; Man'ko, B.V.; Salatskaya, M.I.; Sychev, B.S.

    1980-01-01

    Calculations of regularities to form radiation dose beyond proton accelerator shielding are carried out. Numerical data on photographic monitoring dosemeter in radiation fields investigated are obtained. It was shown how to determine the total equivalent dose of radiation fields beyond proton accelerator shielding by means of the photographic monitoring method by introduction into the procedure of considering nuclear emulsions of division of particle tracks into the black and grey ones. A comparison of experimental and calculational data has shown the applicability of the used calculation method for modelling dose radiation characteristics beyond proton accelerator shielding [ru

  18. Commercial sugar, an alternative dosemeter for the dose determination in radiological emergency conditions

    International Nuclear Information System (INIS)

    Urena N, F.; Galindo, S.

    1997-01-01

    It was carried out the dosimetric evaluation of commercial sugar, with the purpose to determine the feasibility to be able to use this type of substance as a dosimetric material in cases to present some radiological emergency cases. The studied parameters using the Electron Paramagnetic Resonance (EPR) technique were: pre-doses signal or depth signal, dose-response stability, reproducibility, reliability and signal clearing decreasing. (Author)

  19. Determination of alpha-dose rates and chronostratigraphical study of travertine samples

    International Nuclear Information System (INIS)

    Oufni, L.; University Moulay Ismail, Errachidia; Misdaq, M.A.; Boudad, L.; Kabiri, L.

    2001-01-01

    Uranium and thorium contents in different layers of stratigraphical sedimentary deposits have been evaluated by using LR-115 type II and CR-39 solid state nuclear track detectors (SSNTD). A method has been developed for determining the alpha-dose rates of the sedimentary travertine samples. Using the U/Th dating method, we succeeded in age dating carbonated level sampled in the sedimentary deposits. Correlation between the stratigraphy, alpha-dose rates and age has been investigated. (author)

  20. Determination of the dose index in computerized tomography using thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Azorin, J.C.; Calderon, A.; Azorin, J.

    2004-01-01

    In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)

  1. Determining clinical photon beam spectra from measured depth dose with the Cimmino algorithm

    International Nuclear Information System (INIS)

    Bloch, P.; Altschuler, M.D.; Bjaerngard, B.E.; Kassaee, A.; McDonough, J.

    2000-01-01

    A method to determine the spectrum of a clinical photon beam from measured depth-dose data is described. At shallow depths, where the range of Compton-generated electrons increases rapidly with photon energy, the depth dose provides the information to discriminate the spectral contributions. To minimize the influence of contaminating electrons, small (6x6cm2 ) fields were used. The measured depth dose is represented as a linear combination of basis functions, namely the depth doses of monoenergetic photon beams derived by Monte Carlo simulations. The weights of the basis functions were obtained with the Cimmino feasibility algorithm, which examines in each iteration the discrepancy between predicted and measured depth dose. For 6 and 15 MV photon beams of a clinical accelerator, the depth dose obtained from the derived spectral weights was within about 1% of the measured depth dose at all depths. Because the problem is ill conditioned, solutions for the spectrum can fluctuate with energy. Physically realistic smooth spectra for these photon beams appeared when a small margin (about ±1%) was attributed to the measured depth dose. The maximum energy of both derived spectra agreed with the measured energy of the electrons striking the target to within 1 MeV. The use of a feasibility method on minimally relaxed constraints provides realistic spectra quickly and interactively. (author)

  2. Clinical use of carbon-loaded thermoluminescent dosimeters for skin dose determination

    International Nuclear Information System (INIS)

    Ostwald, Patricia M.; Kron, Tomas; Hamilton, Christopher S.; Denham, James W.

    1995-01-01

    Purpose: Carbon-loaded thermoluminescent dosimeters (TLDs) are designed for surface/skin dose measurements. Following 4 years in clinical use at the Mater Hospital, the accuracy and clinical usefulness of the carbon-loaded TLDs was assessed. Methods and Materials: Teflon-based carbon-loaded lithium fluoride (LiF) disks with a diameter of 13 mm were used in the present study. The TLDs were compared with ion chamber readings and TLD extrapolation to determine the effective depth of the TLD measurement. In vivo measurements were made on patients receiving open-field treatments to the chest, abdomen, and groin. Skin entry dose or entry and exit dose were assessed in comparison with doses estimated from phantom measurements. Results: The effective depth of measurement in a 6 MV therapeutic x-ray beam was found to be about 0.10 mm using TLD extrapolation as a comparison. Entrance surface dose measurements made on a solid water phantom agreed well with ion chamber and TLD extrapolation measurements, and black TLDs provide a more accurate exit dose than the other methods. Under clinical conditions, the black TLDs have an accuracy of ± 5% (± 2 SD). The dose predicted from black TLD readings correlate with observed skin reactions as assessed with reflectance spectroscopy. Conclusion: In vivo dosimetry with carbon-loaded TLDs proved to be a useful tool in assessing the dose delivered to the basal cell layer in the skin of patients undergoing radiotherapy

  3. The determination of patient dose from 18F-FDG PET/CT examination

    International Nuclear Information System (INIS)

    Khamwan, K.; Krisanachinda, A.; Pasawang, P.

    2010-01-01

    The use of positron emission tomography/computed tomography (PET/CT) system has heightened the need for medical diagnosis. However, the patient dose is increasing in comparison to whole-body PET/CT dose. The aim of this study is to determine the patient effective dose in 35 oncology Thai patients with the age range of 28-60 y from PET scan using [fluorine-18]-fluoro-2-deoxy-D-glucose and from CT scan. Cumulated activity and residence time of various organs were calculated from time-activity curves by using S-value based on the body mass. Mean organ absorbed dose and the effective dose from CT scan were calculated using the Medical Internal Radiation Dosimetry method and Monte Carlo simulation, respectively. The average whole-body effective doses from PET and CT were 4.40 ± 0.61 and 14.45 ± 2.82 mSv, respectively, resulting in the total patient dose of 18.85 mSv. This can be used as the reference dose in Thai patients. (authors)

  4. Is patient size important in dose determination and optimization in cardiology?

    International Nuclear Information System (INIS)

    Reay, J; Chapple, C L; Kotre, C J

    2003-01-01

    Patient dose determination and optimization have become more topical in recent years with the implementation of the Medical Exposures Directive into national legislation, the Ionising Radiation (Medical Exposure) Regulations. This legislation incorporates a requirement for new equipment to provide a means of displaying a measure of patient exposure and introduces the concept of diagnostic reference levels. It is normally assumed that patient dose is governed largely by patient size; however, in cardiology, where procedures are often very complex, the significance of patient size is less well understood. This study considers over 9000 cardiology procedures, undertaken throughout the north of England, and investigates the relationship between patient size and dose. It uses simple linear regression to calculate both correlation coefficients and significance levels for data sorted by both room and individual clinician for the four most common examinations, left ventrical and/or coronary angiography, single vessel stent insertion and single vessel angioplasty. This paper concludes that the correlation between patient size and dose is weak for the procedures considered. It also illustrates the use of an existing method for removing the effect of patient size from dose survey data. This allows typical doses and, therefore, reference levels to be defined for the purposes of dose optimization

  5. Determination of fluence-to-dose conversion coefficients by means of artificial neural networks

    International Nuclear Information System (INIS)

    Soto B, T. G.; Rivera P, E.; De Leon M, H. A.; Hernandez D, V. M.; Vega C, H. R.; Gallego, E.; Lorente, A.

    2012-10-01

    In this paper is presented an Artificial Neural Network (Ann) that has been designed, trained and validated to determinate the effective dose e, ambient dose equivalent h(10) and personal dose equivalent hp(10,θ) fluence-to-dose conversion coefficients at different positions, having as only input data 7 count rates obtained with a Bonner Sphere Spectrometer (Bss) system. A set of 211 neutron spectra and the fluence-to-dose conversion coefficients published by the International Atomic Energy Agency were used to train and validate the Ann. This set was divided into 2 subsets, one of 181 elements to train the Ann and the remaining 30 to validate it. The Ann was trained using Bss count rates as input data and the fluence-to-dose conversion coefficients as output data. The network was validated and tested with the set of 30 elements that were not used during the training process. Good results were obtained proving that Ann are a good choice for calculating the fluence-to-dose conversion coefficients having as only data the count rates obtained with a Bss. (Author)

  6. Determination of gonad, eye and bone marrow doses with EMI-5005 head and whole body scans

    International Nuclear Information System (INIS)

    Nishizawa, Kanae; Iwata, Takeo; Furuya, Yoshiro; Maruyama, Takashi; Hashizume, Tadashi.

    1979-01-01

    Dose determinations of tissues and organs during head and whole body scanning with an EMI computed tomographic equipment have been carried out using a Rando woman phantom. The surface dose on the phantom was measured with a Sakura lith Contact film dosimeter system. The absorbed doses in the eyes, thyroids, ovaries and the bone marrow were measured with a thermoluminescent dosimeter. The resultant surface doses for head scanning were 2.8 rad (28 mGy) per scan at maximum and 0.26 rad (2.6 mGy) per scan at minimum, and the doses for whole body scanning were 2.7 rad (27 mGy) per scan at maximum and 0.1 rad (1.0 mGy) per scan at minimum. For the complete gynecological scanning consisting of 8 slices, the eye, thyroid, ovary and the bone marrow dose was 2.4 mrad (24 μGy), 3.5 mrad (35 μGy), 500 mrad (5 mGy) and 225 mrad (2.25 mGy), respectively. And, for a typical head scanning consisting of 5 slices, the eye, thyroid, ovary and the bone marrow dose was 1400 mrad (14 mGy), 46 mrad (460 μGy), 0.60 mrad (6 μGy) and 73 mrad (730 μGy), respectively. (author)

  7. Determination of fluence-to-dose conversion coefficients by means of artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Soto B, T. G.; Rivera P, E.; De Leon M, H. A.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Gallego, E.; Lorente, A., E-mail: tzinnia.soto@gmail.com [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, Jose Gutierrez Abascal No. 2, 28006 Madrid (Spain)

    2012-10-15

    In this paper is presented an Artificial Neural Network (Ann) that has been designed, trained and validated to determinate the effective dose e, ambient dose equivalent h(10) and personal dose equivalent hp(10,{theta}) fluence-to-dose conversion coefficients at different positions, having as only input data 7 count rates obtained with a Bonner Sphere Spectrometer (Bss) system. A set of 211 neutron spectra and the fluence-to-dose conversion coefficients published by the International Atomic Energy Agency were used to train and validate the Ann. This set was divided into 2 subsets, one of 181 elements to train the Ann and the remaining 30 to validate it. The Ann was trained using Bss count rates as input data and the fluence-to-dose conversion coefficients as output data. The network was validated and tested with the set of 30 elements that were not used during the training process. Good results were obtained proving that Ann are a good choice for calculating the fluence-to-dose conversion coefficients having as only data the count rates obtained with a Bss. (Author)

  8. Doses determination in UCCA treatments with LDR brachytherapy using Monte Carlo methods

    International Nuclear Information System (INIS)

    Benites R, J. L.; Vega C, H. R.

    2017-10-01

    Using Monte Carlo methods, with the code MCNP5, a gynecological mannequin and a vaginal cylinder were modeled. The spatial distribution of absorbed dose rate in uterine cervical cancer (UCCA) treatments was determined under the modality of manual brachytherapy of low dose rate (B-LDR). The design of the model included the gynecological liquid water mannequin, a vaginal cylinder applicator of Lucite (PMMA) with hemisphere termination. The applicator was formed by a vaginal cylinder 10.3 cm long and 2 cm in diameter. This cylinder was mounted on a stainless steel tube 15.2 cm long by 0.6 cm in diameter. A linear array of four radioactive sources of Cesium 137 was inserted into the tube. 13 water cells of 0.5 cm in diameter were modeled around the vaginal cylinder and the absorbed dose was calculated in these. The distribution of the fluence of gamma photons in the mesh was calculated. It was found that the distribution of the absorbed dose is symmetric for cells located in the upper and lower part of the vaginal cylinder. The values of the absorbed dose rate were estimated for the date of manufacture of the sources. This result allows the use of the law of radioactive decay to determine the dose rate at any date of a gynecological treatment of B-LDR. (Author)

  9. Determination of dose rates in beta radiation fields using extrapolation chamber and GM counter

    International Nuclear Information System (INIS)

    Borg, J.; Christensen, P.

    1995-01-01

    The extrapolation chamber measurement method is the basic method for the determination of dose rates in beta radiation fields and the method has been used for the establishment of beta calibration fields. The paper describes important details of the method and presents results from the measurements of depth-dose profiles from different beta radiation fields with E max values down to 156 keV. Results are also presented from studies of GM counters for use as survey instruments for monitoring beta dose rates at the workplace. Advantages of GM counters are a simple measurement technique and high sensitivity. GM responses were measured from exposures in different beta radiation fields using different filters in front of the GM detector and the paper discusses the possibility of using the results from GM measurements with two different filters in an unknown beta radiation field to obtain a value of the dose rate. (Author)

  10. Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

    CERN Document Server

    Shamma, M A; Sharabi, N

    2002-01-01

    The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays.

  11. Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

    International Nuclear Information System (INIS)

    Shamma, M.; Al-Adawi, M.; Sharabi, N.

    2002-11-01

    The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays. (author)

  12. Trends and the determination of effective doses for standard X-ray procedures

    International Nuclear Information System (INIS)

    Johnson, H.M.; Neduzak, C.; Gallet, J.; Sandeman, J.

    2001-01-01

    Trends in the entrance skin exposures (air kerma) for standard x-ray imaging procedures are reported for the Province of Manitoba, Canada. Average annual data per procedure using standard phantoms and standard ion chambers have been recorded since 1981. For example, chest air kerma (backscatter included) has decreased from 0.14 to 0.09 mGy. Confounding factors may negate the gains unless facility quality control programs are maintained. The data were obtained for a quality assurance and regulatory compliance program. Quoting such data for risk evaluation purposes lacks rigor hence a compartment model for organ apportioning, using organ absorbed doses and weighting factors, has been applied to determine effective dose per procedure. The effective doses for the standard procedures are presented, including the value of 0.027 mSv (1999) calculated for the effective dose in PA chest imaging. (author)

  13. DETERMINATION OF SUPERFICIAL ABSORBED DOSE FROM EXTERNAL EXPOSURE OF WEAKLY PENETRATING RADIATIONS

    Institute of Scientific and Technical Information of China (English)

    陈丽姝

    1994-01-01

    The methods of determining the superficial absorbed dose distributions in a water phantom by means of the experiments and available theories have been reported.The distributions of beta dose were measured by an extrapolation ionization chamber at definite depthes corresponding to some superficial organs and tissues such as the radiosensitive layer of the skin,cornea,sclera,anterior chamber and lens of eyeball.The ratios among superficial absorbed dose D(0.07) and average absorbed doses at the depthes 1,2,3,4,5 and 6mm are also obtained with Cross's methods.They can be used for confining the deterministic effects of some superficial tissues and organs such as the skin and the components of eyeball for weakly penetrating radiations.

  14. Determination of ionizing irradiation summary dose for animals of West Kazakstan

    International Nuclear Information System (INIS)

    Gal'tsev, V.E.; Nasirov, R.N.; Gal'tseva, E.V.; Lebedev, Ya.S.; Bubnov, N.N.

    1996-01-01

    By mean of tooth enamel EPR dosimetry the accumulated radiation doses received animals near Azgyr and Tajsojgan nuclear test sites (West Kazakstan) were determined . In the work camel's two teeth (Tajsojgan) and cow's two teeth (from Azgyr and Tajsojgan test sites - accordingly) were used. Registration of EPR spectrum has been carried out on production-type EPR-spectrometer ESR-300 of Bruker firm under temperature 77 K. SHF power level is 5 MW. Constant magnetic field's modulation frequency was equal to 100 k Hz and modulation amplitude was equal to 3,2 Gs. Received data allow to make conclusion that all tested animals have got summary dose exceeded significantly a natural background radiation dose (1-1,5 μGy/y. Comparison of irradiation dose accumulated in both the front and back tooth walls testifies about predominance of hard γ-rays in the spectrum. 4 refs., 2 figs

  15. Quality audit for dose determination in the field of radiotherapy using TLD

    International Nuclear Information System (INIS)

    Kharita, M. H.; Anjak, O.

    2010-08-01

    Quality audit is one of the important procedures in radiotherapy centers in order to verify the accuracy of the delivered radiation doses. The aim of this work is to establish a procedure for dose audit using TL dosimeters and to apply this procedure in radiotherapy centers. TL Dosimeters were distributed to several radiotherapy centers in Syria and Lebanon (4 with Co-60 and 14 with high energy photon beam radiotherapy units). They were exposed to 2 Gy in order to make an intercomparison study of the absorbed dose in water determined under reference conditions. The results show that only two beams were outside the accepted range, which is ±3.5%. and the were within the accepted range. External Quality audit is one of the important procedures in field of radiotherapy dosimeter in order to verify the accuracy of the radiation doses delivered to patients. (Author)

  16. Determination of the conversion coefficient for ambient dose equivalent, H(10), from air kerma measurements

    International Nuclear Information System (INIS)

    Gonzalez J, F.; Alvarez R, J. T.

    2015-09-01

    Namely the operational magnitudes can be determined by the product of a conversion coefficient by exposure air kerma or fluence, etc. In particular in Mexico for the first time is determined the conversion coefficient (Cc) for operational magnitude Environmental Dose Equivalent H(10) by thermoluminescence dosimetry (TLD) technique. First 30 TLD-100 dosimeters are calibrated in terms of air kerma, then these dosimeters are irradiated inside a sphere ICRU type of PMMA and with the aid of theory cavity the absorbed dose in PMMA is determined at a depth of 10 mm within the sphere D PMMA (10), subsequently absorbed dose to ICRU tissue is corrected and the dose equivalent H(10) is determined. The Cc is determined as the ratio of H(10)/K a obtaining a value of 1.20 Sv Gy -1 with a u c = 3.66%, this being consistent with the published value in ISO-4037-3 of 1.20 Sv Gy -1 with a u c = 2%. (Author)

  17. Determination of attenuation factors for mortar of barite in terms of environmental dose equivalent and effective dose

    International Nuclear Information System (INIS)

    Almeida Junior, Airton T.; Campos, L.L.R.; Araujo, F.G.S.; Santos, M.A.P.; Nogueira, M.S.

    2014-01-01

    This work addresses the characterization of barite mortars used as Xray shielding materials through the following quantities: mass attenuation coefficient, air kerma, effective dose and ambient dose - H⁎(10). The experiment was carried out with the use of the following reference qualities: RQR4, RQR6, RQR9 e RQR10, specified in accordance with norm IEC 61267: Medical diagnostic Xray equipment - radiation conditions for use in the determination of characteristics. In this study values was determined experimentally for the attenuation of the Cream barite (density 2.99g/cm 3 , collected in the state of Sao Paulo), Purple barite (density 2.95g/cm 3 , collected in the state of Bahia) and White barite (density 3.10g/cm 3 , collected in the state of Paraiba). These materials, in the form of mortar, were disposed in the form of squares namely poof bodies, whose dimensions were 10 x 10 cm and thickness ranging from 3 to 15 mm approximately. In the experimental procedure, these proof bodies were irradiated with a Pantak, model HF320 industrial X-ray apparatus. The potentials applied to the respective X-ray tube were: 60kV, 80kV, 120kV and 150kV at a constant current of 1mA. The attenuation responses in function of thickness, for each of the materials analyzed, were used to draw the attenuation and transmission curves. The efficiency of the barite studied concerning the capacity to attenuate X-ray radiation for X-ray beams ranging from 60 to 150 kV indicated

  18. Determination of carcinogenic threshold limit values using the tumorigenic dose rate 50% (TD50)

    International Nuclear Information System (INIS)

    Bonvalot, Y.; Oudiz, A.; Hubert, P.; Abenhaim, L.

    1989-01-01

    The objective of the present study is to propose a simple procedure for the determination of Occupational Limit Values (OLVs) based on the TD 50 concept (Tumorigenic Dose Rate 50%). The TD 50 concept was introduced by Peto R. and al. to help classify chemical substances according to their carcinogenic potency. The TD 50 is that dose rate (in mg/KXg body weight/day) which, if administered chronically for the standard lifespan of the species will halve the probability of remaining tumorless throughout that period. Using TD 50 values available for 776 substances, the procedure presented here allows one to determine OLVs corresponding to a fixed excess risk. It is based on a mathematical high-to-low doses extrapolation of the TD 50 . OLVs obtained with this procedure are compared with currently available TLVs and other occupational guidelines. (author)

  19. Comparision between the IAEA's protocols (TRS-277 and TRS-398) for absorbed dose determination

    International Nuclear Information System (INIS)

    Bero, M.; Anjak, O.

    2007-12-01

    The aim of this study is to compare between two IAEA's Protocols [IAEA-TRS-277 (1987) and IAEA-TRS-398 (2000)] for Absorbed Dose Determination. Five types (5 Chamber) of commonly used cylindrical ionization chambers (Farmer type, 0.6 cc) were used to check the difference in absorbed dose to water determination for Co-60 beams under reference condition. TLD dosimeter was also used for inter-comparison with IAEA's SSDL. The mean values of the measured absorbed dose were found to be similar in both cases and the relative error D (TRS-398)/D (TRS-277) is found to be approximately less than 0.5% for all chambers used in this study.(authors)

  20. Determination of high level absorbed dose in a 60Co gamma ray field with ionization chambers

    International Nuclear Information System (INIS)

    Zhongying Li; Benjiang Mao; Lu Zhang

    1995-01-01

    This paper relates to the principles and methods for determining the absorbed dose of high energy photons radiation with ionization chambers, and its shows the doserate results of high level 60 Co γ-rays in water measured with Farmer chambers. The results with two kinds of chambers at a same point are consistent within 0.3%, and the total uncertainty is less than ± 4%. In the domestic intercomparison on determining high level absorbed dose in which 12 laboratories participated, the deviation of our result from the mean result of the intercomparison is -0.04% [Chen Yundong (1992). Summing up report on a high level absorbed dose intercomparison (in Chinese)]. (author)

  1. Determination of line edge roughness in low-dose top-down scanning electron microscopy images

    NARCIS (Netherlands)

    Verduin, T.; Kruit, P.; Hagen, C.W.

    2014-01-01

    We investigated the off-line metrology for line edge roughness (LER) determination by using the discrete power spectral density (PSD). The study specifically addresses low-dose scanning electron microscopy (SEM) images in order to reduce the acquisition time and the risk of resist shrinkage. The

  2. Determination of air kerma standard of high dose rate 192Ir brachytherapy source

    International Nuclear Information System (INIS)

    Pires, E.J.; Alves, C.F.E.; Leite, S.P.; Magalhaes, L.A.G.; David, M.G.; Almeida, C.E. de

    2015-01-01

    This paper presents the methodology developed by the Laboratorio de Ciencias Radiologicas and presently in use for determining of the air kerma standard of 192 Ir high dose rate sources to calibrate well-type chambers. Uncertainty analysis involving the measurements procedure are presented. (author)

  3. Determination of gamma radiation dose for destruction of Salmonella spp. in chicken flesh

    International Nuclear Information System (INIS)

    Santos, Andreia Ferreira dos

    1997-01-01

    The aim of this study was to determinate: 1) the radio sensibility of Salmonella typhimurium ATCC 14028 in soy trypticase broth; 2) the radio sensibility of Salmonella typhimurium ATCC 14028 in chicken thigh and; 3) to recommend a radiation dose which can be non hazardous for human consumption

  4. Pharmacological dose of alpha-tocopherol induces cardiotoxicity in Wistar rats determined by echocardiography and histology

    Science.gov (United States)

    The effect of pharmacological dose of alpha-tocopherol on heart health was determined in Wistar rats. Animals were randomly assigned to either C (control, n = 11) or E (alpha-tocopherol, n = 11) group. Animals received corn oil (C) or alpha-tocopherol dissolved in corn oil (250 mg alpha-tocopherol/[...

  5. Experimental Determination of the Neutron Radiation-Dose Distribution in the Human Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Stipcic, Neda [Institute Rudjer Bogkovic, Zagreb, Yugoslavia (Serbia)

    1967-01-15

    The quality of the radiation delivering the radiation dose to the human phantom is quite different from that of the incident neutron beam. This paper describes the experimental investigation of the variation of neutron dose related to the variation of neutron fluence with depth in the human phantom. The distribution of neutron radiation was determined in the human phantom - a cube of paraffin wax 25 cm x 25 cm x 50 cm with a density of 0.92 cm{sup -3}. Po-Be and Ra-Be point sources were used as neutron sources. Neutron fluences were measured using different types of detector: scintillation detector, BF{sub 3} counter, and nuclear-track emulsions. Since the fluence measurements with these three types of detectors were carried out under the same experimental conditions, it was possible to separate and analyse each part of the radiation dose in the paraffin. From the investigations, the distribution of the total radiation dose was obtained as a function of the paraffin depth. The maximum value of this dose distribution is constant with respect to the distance between the source and the paraffin phantom. From the results obtained, some conclusions may be drawn concerning the amount of absorbed radiation dose in the human phantom. (author)

  6. Conversion coefficients for determination of dispersed photon dose during radiotherapy: NRUrad input code for MCNP.

    Science.gov (United States)

    Shahmohammadi Beni, Mehrdad; Ng, C Y P; Krstic, D; Nikezic, D; Yu, K N

    2017-01-01

    Radiotherapy is a common cancer treatment module, where a certain amount of dose will be delivered to the targeted organ. This is achieved usually by photons generated by linear accelerator units. However, radiation scattering within the patient's body and the surrounding environment will lead to dose dispersion to healthy tissues which are not targets of the primary radiation. Determination of the dispersed dose would be important for assessing the risk and biological consequences in different organs or tissues. In the present work, the concept of conversion coefficient (F) of the dispersed dose was developed, in which F = (Dd/Dt), where Dd was the dispersed dose in a non-targeted tissue and Dt is the absorbed dose in the targeted tissue. To quantify Dd and Dt, a comprehensive model was developed using the Monte Carlo N-Particle (MCNP) package to simulate the linear accelerator head, the human phantom, the treatment couch and the radiotherapy treatment room. The present work also demonstrated the feasibility and power of parallel computing through the use of the Message Passing Interface (MPI) version of MCNP5.

  7. Improvement of dose determination using glass display of mobile phones for accident dosimetry

    International Nuclear Information System (INIS)

    Discher, M.; Woda, C.; Fiedler, I.

    2013-01-01

    Previous studies have demonstrated that mobile phones can be used as suitable emergency dosimeters in case of an accidental radiation overexposure. Glass samples extracted from displays of mobile phones are sensitive to ionizing radiation and can be measured using the thermoluminescence (TL) method. A non-radiation induced background signal (so-called zero dose signal) was observed which overlaps with the radiation induced signal and consequently limits the minimum detectable dose. Investigations of several glasses from different displays showed that it is possible to reduce the zero dose signal up to 90% by etching the glass surface with concentrated hydrofluoric acid. With this approach a reduction of the detection limit of a factor of four, corresponding to approximately 80 mGy, was achieved. Dosimetric properties of etched samples are presented and developed protocols validated by dose recovery tests under realistic conditions. With the improvements in sample preparation the proposed method of dose determination is a competitive alternative to OSL/TL measurements of electronic components and chip cards and provides a useful option for retrospective accident dosimetry. -- Highlights: ► Glass displays from mobile phones have good potential for emergency dosimetry. ► The background signal can be reduced by etching glass samples with hydrofluoric acid. ► The minimum detectable dose can be lowered to approximately 80 mGy

  8. Regression models in the determination of the absorbed dose with extrapolation chamber for ophthalmological applicators

    International Nuclear Information System (INIS)

    Alvarez R, J.T.; Morales P, R.

    1992-06-01

    The absorbed dose for equivalent soft tissue is determined,it is imparted by ophthalmologic applicators, ( 90 Sr/ 90 Y, 1850 MBq) using an extrapolation chamber of variable electrodes; when estimating the slope of the extrapolation curve using a simple lineal regression model is observed that the dose values are underestimated from 17.7 percent up to a 20.4 percent in relation to the estimate of this dose by means of a regression model polynomial two grade, at the same time are observed an improvement in the standard error for the quadratic model until in 50%. Finally the global uncertainty of the dose is presented, taking into account the reproducibility of the experimental arrangement. As conclusion it can infers that in experimental arrangements where the source is to contact with the extrapolation chamber, it was recommended to substitute the lineal regression model by the quadratic regression model, in the determination of the slope of the extrapolation curve, for more exact and accurate measurements of the absorbed dose. (Author)

  9. Committed effective dose determination in cereal flours by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Scheibel, Viviane

    2006-01-01

    The health impact from radionuclides ingestion of foodstuffs was evaluated by the committed effective doses determined in commercial samples of South-Brazilian cereal flours (soy, wheat, corn, manioc, rye, oat, barley and rice flour). The radioactivity traces of 228 Th, 228 Ra, 226 Ra, 40 K, 7 Be and 137 Cs were measured by gamma-ray spectrometry employing a 66% relative efficiency HPGe detector. The energy resolution for the 1332.46 keV line of 60 Co was 2.03 keV. The committed effective doses were calculated with the activities analyzed in the present flour samples, the foodstuff rates of consumption (Brazilian Institute of Geography and Statistics) and the ingestion dose coefficients (International Commission of Radiological Protection). The reliability median activities were verified with χ 2 tests, assuring the fittings quality. The highest concentration levels of 228 Th and 40 K were 3.5 ± 0.4 and 1469 ± 17 Bq.kg -1 for soy flour, respectively, with 95% of confidence level. The lower limit of detection for 137 Cs ranged from 0.04 to 0.4 Bq.kg -1 . The highest committed effective dose was 0.36 μSv.y -1 for 228 Ra in manioc flour (adults). All committed effective doses determined at the present work were lower than the UNSCEAR limits of 140 μSv.y -1 and much lower than the ICRP (1991) limits of 1 mSv.y -1 , for general public. There are few literature references for natural and artificial radionuclides in foodstuffs and mainly for committed effective doses. This work brings the barley flour data, which is not present at the literature and 7 Be data which is not encountered in foodstuffs at the literature, besides all the other flours data information about activities and committed effective doses. (author)

  10. Analysis of Radiation Accident of Non-destructive Inspection and Rational Preparing Bills

    International Nuclear Information System (INIS)

    Bae, Junwoo; Yoo, Donghan; Kim, Hee Reyoung

    2013-01-01

    After 2006, according to enactment of Non-destructive Inspection Promotion Act, the number of non-destructive inspection companies and corresponding accident is increased sharply. In this research, it includes characteristic analysis of field of the non-destructive inspection. And from the result of analysis, the purpose of this research is discovering reason for 'Why there is higher accident ratio in non-destructive inspection field, relatively' and preparing effective bill for reducing radiation accidents. The number of worker for non-destructive inspect is increased steadily and non-destructive inspect worker take highest dose. Corresponding to these, it must be needed to prepare bills to protect non-destructive inspect workers. By analysis of accident case, there are many case of carelessness that tools are too heavy to carry it everywhere workers go. And there are some cases caused by deficiency of education that less understanding of radiation and poor operation by less understanding of structure of tools. Also, there is no data specialized to non-destructive inspect field. So, it has to take information from statistical data. Because of this, it is hard to analyze nondestructive inspect field accurately. So, it is required to; preparing rational bills to protect non-destructive inspect workers nondestructive inspect instrument lightening and easy manual which can understandable for low education background people accurate survey data from real worker. To accomplish these, we needs to do; analyze and comprehend the present law about non-destructive inspect worker understand non-destructive inspect instruments accurately and conduct research for developing material developing rational survey to measuring real condition for non-destructive inspect workers

  11. Technical regulation of nondestructive inspection

    International Nuclear Information System (INIS)

    1995-01-01

    It starts with the explanation of definition of nondestructive inspection and qualifications for a inspection. It lists the technical regulations of nondestructive inspections which are radiographic testing, ultrasonic flaw detecting test, liquid penetrant test, magnetic particle inspection, eddy current test visual inspection and leakage test.

  12. Determination of absorbed dose in a proton beam for purposes of charged-particle radiation therapy

    International Nuclear Information System (INIS)

    Verhey, L.J.; Koehler, A.M.; McDonald, J.C.; Goitein, M.; Ma, I.C.; Schneider, R.J.; Wagner, M.

    1979-01-01

    Four methods are described by which absorbed dose has been measured in a proton beam extracted from the 160-MeV Harvard cyclotron. The standard dosimetry, used to determine doses for patient treatments, is based upon an absolute measurement of particle flux using a Faraday cup. Measurements have also been made using a parallel-plate ionization chamber; a thimble ionization chamber carying a 60 Co calibration traceable to NBS; and a tissue-equivalent calorimeter. The calorimeter, which provides an independent check of the dosimetry, agreed with the standard dosimetry at five widely different depths within a range from 0.8 to 2.6%

  13. Absorbed dose determination in high energy photon beams using new IAEA TRS - 398 Code of Practice

    International Nuclear Information System (INIS)

    Suriyapee, S.; Srimanoroath, S.; Jumpangern, C.

    2002-01-01

    The absorbed dose calibration of 6 and 10 MV X-ray beams from Varian Clinac 1800 at King Chulalongkorn Memorial Hospital Bangkok, Thailand were performed using cylindrical chamber 0.6 cc NE2571 Serial No. 1633 with graphite wall and Delrin build up cap and lonex Dosemaster NE 2590 Serial No. 223. The absorbed dose determination followed the IAEA code of practice TRS-277. The new IAEA code of practice TRS-398 have been studied to compare the result with the IAEA TRS-277

  14. Investigation of initial contamination for disposal medical infusion items and determination of sterilization dose

    International Nuclear Information System (INIS)

    Hu Jinhui; Xu Ziyan; Sun Naifeng; Yan Aoshuang; Gao Wei; Wang Binglin

    1993-01-01

    Statistical analyses on initial contamination of 624 disposal medical infusion items are made. The normal distribution of the initial contamination, the relation of initial contamination of inner and outer walls of disposal medical infusion items and the changes of initial contamination before irradiation are shown. The sterilized dose for disposal infusion is determined as 17.2 kGy using bioburden information. The SAL (sterility assurance level) dose is 10 6 . The SIP (device sample item proportion) is 1 and the average initial contamination is 7 CFU/item

  15. Three-dimensional absorbed dose determinations by N.M.R. analysis of phantom-dosemeters

    International Nuclear Information System (INIS)

    Gambarini, G.; Birattari, C.; Fumagalli, M.L.; Vai, A.; Monti, D.; Salvadori, P.; Facchielli, L.; Sichirollo, A.E.

    1996-01-01

    Magnetic resonance imaging of a tissue-equivalent phantom is a promising technique for three-dimensional determination of absorbed dose from ionizing radiation. A reliable method of determining the spatial distribution of absorbed dose is indispensable for the planning of treatment in the presently developed radiotherapy techniques aimed at obtaining high energy selectively delivered to cancerous tissues, with low dose delivered to the surrounding healthy tissue. Aqueous gels infused with the Fricke dosemeter (i.e. with a ferrous sulphate solution), as proposed in 1984 by Gore et al., have shown interesting characteristics and, in spite of some drawbacks that cause a few limitations to their utilisation, they have shown the feasibility of three-dimensional dose determinations by nuclear magnetic resonance (NMR) imaging. Fricke-infused agarose gels with various compositions have been analysed, considering the requirements of the new radiotherapy techniques, in particular Boron Neutron Capture Therapy (B.N.C.T.) and proton therapy. Special attention was paid to obtain good tissue equivalence for every radiation type of interest. In particular, the tissue equivalence for thermal neutrons, which is a not simple problem, has also been satisfactorily attained. The responses of gel-dosemeters having the various chosen compositions have been analysed, by mean of NMR instrumentation. Spectrophotometric measurements have also been performed, to verify the consistence of the results. (author)

  16. Applicability of a prototype for determination of absorbed dose using brachytherapy equipment with Ir-192 sources

    International Nuclear Information System (INIS)

    Souza, Vivianne Lucia Bormann; Almeida, Mayara Gabriella Oliveira de; Vieira, Rafaela Etelvina de Amorim; Silva, Waldecy Ananias da; Nascimento, Rizia Keila

    2014-01-01

    This work aims at the development and improvement of a device to perform the absolute dosimetry sources of Ir-192 using the Fricke solution contained in a flask. The Fricke solution used was prepared using amounts of ferrous ammonium sulfate, sodium chloride and sulfuric acid, diluted with water tri distilled pre-established in the literature. The spectrophotometer used was a UV-VIS spectrophotometer (Beckman DU-640 Counter) for measuring the optical density at wavelength 304 nm. The calculation for determining the radial dose takes into account the radial distance and the angle formed with the transverse axis of the source. As the results obtained can be seen that the states of Pernambuco, Ceara, Paraiba e Piaui are in accordance with the recommendations of international standards of the International Atomic Energy Agency (IAEA), which considers not acceptable a difference greater than 5% of prescribed dose and measured dose

  17. Field dose radiation determination by active learning with Gaussian Process for autonomous robot guiding

    International Nuclear Information System (INIS)

    Freitas Naiff, Danilo de; Silveira, Paulo R.; Pereira, Claudio M.N.A.

    2017-01-01

    This article proposes an approach for determination of radiation dose pro le in a radiation-susceptible environment, aiming to guide an autonomous robot in acting on those environments, reducing the human exposure to dangerous amount of dose. The approach consists of an active learning method based on information entropy reduction, using log-normally warped Gaussian Process (GP) as surrogate model, resulting in non-linear online regression with sequential measurements. Experiments with simulated radiation dose fields of varying complexity were made, and results showed that the approach was effective in reconstruct the eld with high accuracy, through relatively few measurements. The technique was also shown some robustness in presence measurement noise, present in real measurements, by assuming Gaussian noise. (author)

  18. Field dose radiation determination by active learning with Gaussian Process for autonomous robot guiding

    Energy Technology Data Exchange (ETDEWEB)

    Freitas Naiff, Danilo de; Silveira, Paulo R.; Pereira, Claudio M.N.A., E-mail: danilonai1992@poli.ufrj.br, E-mail: paulo@lmp.ufrj.br, E-mail: cmnap@ien.gov.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-11-01

    This article proposes an approach for determination of radiation dose pro le in a radiation-susceptible environment, aiming to guide an autonomous robot in acting on those environments, reducing the human exposure to dangerous amount of dose. The approach consists of an active learning method based on information entropy reduction, using log-normally warped Gaussian Process (GP) as surrogate model, resulting in non-linear online regression with sequential measurements. Experiments with simulated radiation dose fields of varying complexity were made, and results showed that the approach was effective in reconstruct the eld with high accuracy, through relatively few measurements. The technique was also shown some robustness in presence measurement noise, present in real measurements, by assuming Gaussian noise. (author)

  19. Double dosimetry procedures for the determination of occupational effective dose in interventional radiology

    International Nuclear Information System (INIS)

    Jaervinen, H.; Buls, N.; Clerinx, P.; Miljanic, S.; Ranogajec-Komor, M.; Nikodemova, D.; D'Errico, F.

    2008-01-01

    Full text: In interventional radiology, for an accurate determination of occupational effective dose, measurements with two dosemeters ('double dosimetry', DD) have been recommended, one dosemeter located above and one under the protective apron. In this paper, based on an extensive literature search, the most recent algorithms developed for the determination of effective dose from the dosimeter readings have been compared for a few practical interventional procedures. Recommendations on the practices and algorithms are given on the basis of the results. For the comparison of algorithms, dosemeter readings and the effective dose were obtained both experimentally and by calculation. Further, data from published Monte Carlo calculations have been applied. The literature review has indicated that very few regulations for DD exist and the DD practices have not been harmonized. There is no firm consensus on the most suitable calculation algorithms. Single dosemeter (SD) measurements are still mostly used for the calculation of effective dose. Most DD and SD algorithms overestimate effective dose significantly, sometimes by over ten times. However, SD algorithms can significantly underestimate effective dose in certain interventional radiology conditions. Due to the possibility of underestimating effective dose, DD is generally recommended. The results suggest that there might not be a single DD algorithm which would be optimum for all interventional radiology procedures. However, the selection of a precise DD algorithm for each individual condition is not practical and compromises must be made. For accurate personnel dosimetry, the accuracy of the algorithm selected should be tested for typical local interventional radiology condition. Personnel dosemeters should be used in the recommended positions. The dosemeter above the apron should be on a collar and its reading also used to assess the risk of lens injuries. The dosemeter under the apron can be on the chest or

  20. Radiation absorbed dose estimate for rubidium-82 determined from in vivo measurements in human subjects

    International Nuclear Information System (INIS)

    Ryan, J. W.; Harper, P.V.; Stark, V.S.; Peterson, E.L.; Lathrop, K.A.

    1986-01-01

    Radiation absorbed doses from rubidium-82 injected intravenously were determined in two young men, aged 23 and 27, using a dynamic conjugate counting technique to provide data for the net organ integrated time-activity curves in five organs: kidneys, lungs, liver, heart, and testes. This technique utilized a tungsten collimated Anger camera and the accuracy was validated in a prestwood phantom. The data for each organ were compared with conjugate count rates of a reference Ge-68/Ga-68 standard which had been calibrated against the Rb-82 injected. The effects of attenuation in the body were eliminated. The MIRD method was used to calculate the organ self absorbed doses and the total organ absorbed doses. The mean total absorbed doses were as follows (mrads/mCi injected): kidneys 30.9, heart walls 7.5, lungs 6.0, liver 3.0, testes 2.0 (one subject only), red marrow 1.3, remainder of body 1.3 and, extrapolating to women, ovaries 1.2. This absorbed dose to the kidney is significantly less than the pessimistic estimate of 59.4 mrads/mCi, made assuming instantaneous uptake and complete extraction of activity with no excretion by the kidneys, which receive 20% of the cardiac output. Further, in a 68 year old man the renal self absorbed dose was approximately 40% less than the mean renal self absorbed dose of the younger men. This decrease is probably related to the decline in renal blood flow which occurs with advancing age but other factors may also contribute to the observed difference. 14 references, 4 figures, 2 tables

  1. Determination of the delivered hemodialysis dose using standard methods and on-line clearance monitoring

    Directory of Open Access Journals (Sweden)

    Vlatković Vlastimir

    2006-01-01

    Full Text Available Background/aim: Delivered dialysis dose has a cumulative effect and significant influence upon the adequacy of dialysis, quality of life and development of co-morbidity at patients on dialysis. Thus, a great attention is given to the optimization of dialysis treatment. On-line Clearance Monitoring (OCM allows a precise and continuous measurement of the delivered dialysis dose. Kt/V index (K = dialyzer clearance of urea; t = dialysis time; V = patient's total body water, measured in real time is used as a unit for expressing the dialysis dose. The aim of this research was to perform a comparative assessment of the delivered dialysis dose by the application of the standard measurement methods and a module for continuous clearance monitoring. Methods. The study encompassed 105 patients who had been on the chronic hemodialysis program for more than three months, three times a week. By random choice, one treatment per each controlled patient was taken. All the treatments understood bicarbonate dialysis. The delivered dialysis dose was determined by the calculation of mathematical models: Urea Reduction Ratio (URR singlepool index Kt/V (spKt/V and by the application of OCM. Results. Urea Reduction Ratio was the most sensitive parameter for the assessment and, at the same time, it was in the strongest correlation with the other two, spKt/V indexes and OCM. The values pointed out an adequate dialysis dose. The URR values were significantly higher in women than in men, p < 0.05. The other applied model for the delivered dialysis dose measurement was Kt/V index. The obtained values showed that the dialysis dose was adequate, and that, according to this parameter, the women had significantly better dialysis, then the men p < 0.05. According to the OCM, the average value was slightly lower than the adequate one. The women had a satisfactory dialysis according to this index as well, while the delivered dialysis dose was insufficient in men. The difference

  2. Determination of Effect of Low Dose Vs Moderate Dose of Clofibrate on the Decreasing in Serum Bilirubin Level in the Term Healthy Neonate

    OpenAIRE

    Mohammad Ashkan Moslehi; Narges Pishva

    2007-01-01

    Objective: This study was performed to determine the effect of low doses (25 mg/Kg) vs. moderate doses (50 mg/Kg) of clofibrate in treatment of non-hemolytic hyperbilirubin¬emia in healthy term neonates. Material & Methods: A clinical randomized controlled trial was performed in three groups of healthy term neonates. One group was treated with a single low dose of clofibrate (25 mg/Kg) while another group received a single moderate dose (50mg/kg) both orally plus phototherapy; the results wer...

  3. Real time determination of dose radiation through artificial intelligence and virtual reality

    International Nuclear Information System (INIS)

    Freitas, Victor G.G.; Mol, Antonio C.A.; Pereira, Claudio M.N.A.

    2009-01-01

    In the last years, a virtual environment of Argonauta research reactor, sited in the Instituto de Engenharia Nuclear (Brazil), has been developed. Such environment, called here Argonauta Virtual (AV), is a 3D model of the reactor hall, in which virtual people (avatar) can navigate. In AV, simulations of nuclear sources and doses are possible. In a recent work, a real time monitoring system (RTMS) was developed to provide (by means of Ethernet TCP/IP) the information of area detectors situated in the reactor hall. Extending the scope of AV, this work is intended to provide a continuous determination of gamma radiation dose in the reactor hall, based in several monitored parameters. To accomplish that a module based in artificial neural network (ANN) was developed. The ANN module is able to predict gamma radiation doses using as inputs: the avatar position (from virtual environment), the reactor power (from RTMS) and information of fixed area detectors (from RTMS). The ANN training data has been obtained by measurements of gamma radiation doses in a mesh of points, with previously defined positions, for different power levels. Through the use of ANN it is possible to estimate, in real time, the dose received by a person at any position in Argonauta reactor hall. Such approach allows tasks simulations and training of people inside the AV system, without exposing them to radiation effects. (author)

  4. Radiation dose determines the method for quantification of DNA double strand breaks

    International Nuclear Information System (INIS)

    Bulat, Tanja; Keta, Olitija; Korićanac, Lela; Žakula, Jelena; Petrović, Ivan; Ristić-Fira, Aleksandra; Todorović, Danijela

    2016-01-01

    Ionizing radiation induces DNA double strand breaks (DSBs) that trigger phosphorylation of the histone protein H2AX (γH2AX). Immunofluorescent staining visualizes formation of γH2AX foci, allowing their quantification. This method, as opposed to Western blot assay and Flow cytometry, provides more accurate analysis, by showing exact position and intensity of fluorescent signal in each single cell. In practice there are problems in quantification of γH2AX. This paper is based on two issues: the determination of which technique should be applied concerning the radiation dose, and how to analyze fluorescent microscopy images obtained by different microscopes. HTB140 melanoma cells were exposed to γ-rays, in the dose range from 1 to 16 Gy. Radiation effects on the DNA level were analyzed at different time intervals after irradiation by Western blot analysis and immunofluorescence microscopy. Immunochemically stained cells were visualized with two types of microscopes: AxioVision (Zeiss, Germany) microscope, comprising an ApoTome software, and AxioImagerA1 microscope (Zeiss, Germany). Obtained results show that the level of γH2AX is time and dose dependent. Immunofluorescence microscopy provided better detection of DSBs for lower irradiation doses, while Western blot analysis was more reliable for higher irradiation doses. AxioVision microscope containing ApoTome software was more suitable for the detection of γH2AX foci. (author)

  5. Determination of dose ranges of gamma rays to induce specific changes in three ornamental species

    International Nuclear Information System (INIS)

    Gonzalez J, J.

    2011-11-01

    In order to confirming the possibility of to settle a dose range that takes place directly and not at random, a specific effect independently of the species that is were produced several similar organisms to three ornamental species took place via meristems cultivation: Petunia hybrid, Impatiens walleriana and Sprekelia formosissima, same that were irradiated in an irradiator Gamma cell 220, to different dose: 0, 3.5, 5.0, 7.5, 10, 12.5, 15, 17.5 and 20 Gy. Later on, of the plants treated via in vitro the subsequent generations were obtained until the M 4 . To determine the DL 50 and the possible good doses, the survival parameters, development, morphogenesis and height were evaluated during 8 weeks, interpreting based on them, the possible physiologic and genetic alterations induced by the radiation. The established DL 50 were: 7.5 Gy (Petunia), 19.0 Gy (Impatiens) and 12.0 Gy (Sprekelia). Based on the DL 50 of each species, a range of coincident dose settled down that produces a similar effect in the three species: a range of DL 23 to the DL 50 induces and alteration in the cytokinins production affecting directly in the leaves number, buds and plants taken place by meristem, also a range of DL 32 - DL 50 impacts in the auxins production altering to the radicule system. However, when being superimposed the dose is considered that the investigation should continue. (Author)

  6. Radiation dose determines the method for quantification of DNA double strand breaks

    Energy Technology Data Exchange (ETDEWEB)

    Bulat, Tanja; Keta, Olitija; Korićanac, Lela; Žakula, Jelena; Petrović, Ivan; Ristić-Fira, Aleksandra [University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade (Serbia); Todorović, Danijela, E-mail: dtodorovic@medf.kg.ac.rs [University of Kragujevac, Faculty of Medical Sciences, Kragujevac (Serbia)

    2016-03-15

    Ionizing radiation induces DNA double strand breaks (DSBs) that trigger phosphorylation of the histone protein H2AX (γH2AX). Immunofluorescent staining visualizes formation of γH2AX foci, allowing their quantification. This method, as opposed to Western blot assay and Flow cytometry, provides more accurate analysis, by showing exact position and intensity of fluorescent signal in each single cell. In practice there are problems in quantification of γH2AX. This paper is based on two issues: the determination of which technique should be applied concerning the radiation dose, and how to analyze fluorescent microscopy images obtained by different microscopes. HTB140 melanoma cells were exposed to γ-rays, in the dose range from 1 to 16 Gy. Radiation effects on the DNA level were analyzed at different time intervals after irradiation by Western blot analysis and immunofluorescence microscopy. Immunochemically stained cells were visualized with two types of microscopes: AxioVision (Zeiss, Germany) microscope, comprising an ApoTome software, and AxioImagerA1 microscope (Zeiss, Germany). Obtained results show that the level of γH2AX is time and dose dependent. Immunofluorescence microscopy provided better detection of DSBs for lower irradiation doses, while Western blot analysis was more reliable for higher irradiation doses. AxioVision microscope containing ApoTome software was more suitable for the detection of γH2AX foci. (author)

  7. Real time determination of dose radiation through artificial intelligence and virtual reality

    International Nuclear Information System (INIS)

    Freitas, Victor Goncalves Gloria

    2009-01-01

    In the last years, a virtual environment of Argonauta research reactor, sited in the Instituto de Engenharia Nuclear (Brazil), has been developed. Such environment, called here Argonauta Virtual (AV), is a 3D model of the reactor hall, in which virtual people (avatar) can navigate. In AV, simulations of nuclear sources and doses are possible. In a recent work, a real time monitoring system (RTMS) was developed to provide (by means of Ethernet TCP/I P) the information of area detectors situated in the reactor hall. Extending the scope of AV, this work is intended to provide a continuous determination of gamma radiation dose in the reactor hall, based in several monitored parameters. To accomplish that a module based in artificial neural network (ANN) was developed. The ANN module is able to predict gamma radiation doses using as inputs: the avatar position (from virtual environment), the reactor power (from RTMS) and information of fixed area detectors (from RTMS). The ANN training data has been obtained by measurements of gamma radiation doses in a mesh of points, with previously defined positions, for different power levels. Through the use of ANN it is possible to estimate, in real time, the dose received by a person at any position in Argonauta reactor hall. Such approach allows tasks simulations and training of people inside the AV system, without exposing them to radiation effects. (author)

  8. Determination of eye lenses dose equivalent in terms of Hp(3)

    International Nuclear Information System (INIS)

    Klamert, V.; Caresana, M.; Minchillo, G.; Tambussi, O.

    2002-01-01

    The Italian radioprotection legislation requires the determination of personal dose equivalent in terms of H p (10) and H p (0.07) and the determination of the eye lenses dose equivalent in terms of H p (3). Whereas the calibration of a dosemeter for the determination of H p (10) and H p (0.07) is feasible, the calibration of a dosemeter in terms of H p (3) is impossible, owing to the absence of the suitable phantom and the conversion coefficients h pk (3) from air kerma to H p (3). Using an anthropomorphic phantom for the irradiation, the aim of this work is to determine the experimental values of the conversion coefficients and to relate the result of the dosemeter worn on the forehead with the dose equivalent to the eye lenses. The study is performed in the X energy range from 30 keV to 100 keV, i.e. the one most widely used in medical practices

  9. Absorbed dose determination in kilovoltage X-ray synchrotron radiation using alanine dosimeters.

    Science.gov (United States)

    Butler, D J; Lye, J E; Wright, T E; Crossley, D; Sharpe, P H G; Stevenson, A W; Livingstone, J; Crosbie, J C

    2016-12-01

    Alanine dosimeters from the National Physical Laboratory (NPL) in the UK were irradiated using kilovoltage synchrotron radiation at the imaging and medical beam line (IMBL) at the Australian Synchrotron. A 20 × 20 mm 2 area was irradiated by scanning the phantom containing the alanine through the 1 mm × 20 mm beam at a constant velocity. The polychromatic beam had an average energy of 95 keV and nominal absorbed dose to water rate of 250 Gy/s. The absorbed dose to water in the solid water phantom was first determined using a PTW Model 31014 PinPoint ionization chamber traceable to a graphite calorimeter. The alanine was read out at NPL using correction factors determined for 60 Co, traceable to NPL standards, and a published energy correction was applied to correct for the effect of the synchrotron beam quality. The ratio of the doses determined by alanine at NPL and those determined at the synchrotron was 0.975 (standard uncertainty 0.042) when alanine energy correction factors published by Waldeland et al. (Waldeland E, Hole E O, Sagstuen E and Malinen E, Med. Phys. 2010, 37, 3569) were used, and 0.996 (standard uncertainty 0.031) when factors by Anton et al. (Anton M, Büermann L., Phys Med Biol. 2015 60 6113-29) were used. The results provide additional verification of the IMBL dosimetry.

  10. Determining dose rate with a semiconductor detector - Monte Carlo calculations of the detector response

    Energy Technology Data Exchange (ETDEWEB)

    Nordenfors, C

    1999-02-01

    To determine dose rate in a gamma radiation field, based on measurements with a semiconductor detector, it is necessary to know how the detector effects the field. This work aims to describe this effect with Monte Carlo simulations and calculations, that is to identify the detector response function. This is done for a germanium gamma detector. The detector is normally used in the in-situ measurements that is carried out regularly at the department. After the response function is determined it is used to reconstruct a spectrum from an in-situ measurement, a so called unfolding. This is done to be able to calculate fluence rate and dose rate directly from a measured (and unfolded) spectrum. The Monte Carlo code used in this work is EGS4 developed mainly at Stanford Linear Accelerator Center. It is a widely used code package to simulate particle transport. The results of this work indicates that the method could be used as-is since the accuracy of this method compares to other methods already in use to measure dose rate. Bearing in mind that this method provides the nuclide specific dose it is useful, in radiation protection, since knowing what the relations between different nuclides are and how they change is very important when estimating the risks

  11. Determination of photon conversion factors relating exposure and dose for several extremity phantom designs

    International Nuclear Information System (INIS)

    Roberson, P.L.; Eichner, F.N.; Reece, W.D.

    1986-09-01

    This report presents the results of measurements of dosimetric properties of simple extremity phantoms suitable for use in extremity dosimeter performance testing. Two sizes of phantoms were used in this study. One size represented the forearm or lower leg and the other size represented the finger or toe. For both phantom sizes, measurements were performed on solid plastic phantoms and on phantoms containing simulated bone material to determine the effect of backscattered radiations from the bone on the surface dose. Exposure-to-dose conversion factors (C/sub x/ factors) were determined for photon energies ranging from 16 to 1250 keV (average for 60 Co). The effect of the presence of a phantom was also measured for a 90 Sr/ 90 Y source. Significant differences in the measured C/sub x/ factors were found among the phantoms investigated. The factors for the finger-sized phantoms were uniformly less than for the arm-sized phantoms

  12. On the absorbed dose determination method in high energy photon beams

    International Nuclear Information System (INIS)

    Scarlat, F.; Scarisoreanu, A.; Oane, M.; Mitru, E.; Avadanei, C.

    2008-01-01

    The absorbed dose determination method in water, based on standards of air kerma or exposure in high energy photon beams generated by electron with energies in the range of 1 MeV to 50 MeV is presented herein. The method is based on IAEA-398, AAPM TG-51, DIN 6800-2, IAEA-381, IAEA-277 and NACP-80 recommendations. The dosimetry equipment is composed of UNIDOS T 10005 electrometer and different ionization chambers calibrated in air kerma method in a Co 60 beam. Starting from the general formalism showed in IAEA-381, the determination of absorbed dose in water, under reference conditions in high energy photon beams, is given. This method was adopted for the secondary standard dosimetry laboratory (SSDL) in NILPRP-Bucharest

  13. Determination method of inactivating minimal dose of gama radiation for Salmonella typhimurium

    International Nuclear Information System (INIS)

    Araujo, E.S.; Campos, H. de; Silva, D.M.

    1979-01-01

    A method for determination of minimal inactivating dose (MID) with Salmonella typhimurium is presented. This is a more efficient way to improve the irradiated vaccines. The MID found for S. thyphimurium 6.616 by binomial test was 0.55 MR. The method used allows to get a definite value for MID and requires less consumption of material, work and time in comparison with the usual procedure [pt

  14. On the absorbed dose determination method in high energy electrons beams

    International Nuclear Information System (INIS)

    Scarlat, F.; Scarisoreanu, A.; Oane, M.; Mitru, E.; Avadanei, C.

    2008-01-01

    The absorbed dose determination method in water for electron beams with energies in the range from 1 MeV to 50 MeV is presented herein. The dosimetry equipment for measurements is composed of an UNIDOS.PTW electrometer and different ionization chambers calibrated in air kerma in a Co 60 beam. Starting from the code of practice for high energy electron beams, this paper describes the method adopted by the secondary standard dosimetry laboratory (SSDL) in NILPRP - Bucharest

  15. A photon spectrometric dose-rate constant determination for the Advantage™ Pd-103 brachytherapy source

    OpenAIRE

    Chen, Zhe Jay; Bongiorni, Paul; Nath, Ravinder

    2010-01-01

    Purpose: Although several dosimetric characterizations using Monte Carlo simulation and thermoluminescent dosimetry (TLD) have been reported for the new Advantage™ Pd-103 source (IsoAid, LLC, Port Richey, FL), no AAPM consensus value has been established for the dosimetric parameters of the source. The aim of this work was to perform an additional dose-rate constant (Λ) determination using a recently established photon spectrometry technique (PST) that is independent of the published TLD and ...

  16. Absorbed dose determination in water in medium energy x-ray beam

    International Nuclear Information System (INIS)

    Nisevic, G.; Spasic-Jokic, V.

    1998-01-01

    Absorbed dose determination in water phantom in medium energy X-ray beam, according to IAEA recommendations is given. This method is applied on Radiotherapy department of Military Academy Hospital in Belgrade. Reference points of measurements are on depth of 5 cm and 2 cm as it recommended in ref. Experimental results are shown in aim to introduce new dosimetric concept based on air kerma calibration factor recommended for application in our radiotherapy centers (author)

  17. Non-destructive inservice inspections

    International Nuclear Information System (INIS)

    Kauppinen, P.; Sarkimo, M.; Lahdenperae, K.

    1998-01-01

    In order to assess the possible damages occurring in the components and structures of operating nuclear power plants during service the main components and structures are periodically inspected by non-destructive testing techniques. The reliability of non-destructive testing techniques applied in these inservice inspections is of major importance because the decisions concerning the needs for repair of components are mainly based on the results of inspections. One of the targets of this research program has been to improve the reliability of non-destructive testing. This has been addressed in the sub-projects which are briefly summarised here. (author)

  18. Passive Dosing to Determine the Speciation of Hydrophobic Organic Chemicals in Aqueous Samples

    DEFF Research Database (Denmark)

    Birch, Heidi; Gouliarmou, V.; Lützhøft, Hans-Christian Holten

    2010-01-01

    A new analytical approach to determine the speciation of hydrophobic organic analytes is presented. The freely dissolved concentration in a sample is controlled by passive dosing from silicone (poly(dimethylsiloxane)), and the total sample concentration at equilibrium is measured. The free fraction...... is determined as the ratio between measured concentrations in pure water and sample. C-14-labeled fluoranthene served as model analyte, and total sample concentrations were easily measured by liquid scintillation counting. The method was applied to surface water, stormwater runoff, and wastewater...... (SPME). This analytical approach combines simplicity with high precision, and it does not require any phase separation steps....

  19. An absolute dose determination of helical tomotherapy accelerator, TomoTherapy High-Art II

    International Nuclear Information System (INIS)

    Bailat, Claude J.; Buchillier, Thierry; Pachoud, Marc; Moeckli, Raphaeel; Bochud, Francois O.

    2009-01-01

    Purpose: A helical tomotherapy accelerator presents a dosimetric challenge because, to this day, there is no internationally accepted protocol for the determination of the absolute dose. Because of this reality, we investigated the different alternatives for characterizing and measuring the absolute dose of such an accelerator. We tested several dosimetric techniques with various metrological traceabilities as well as using a number of phantoms in static and helical modes. Methods: Firstly, the relationship between the reading of ionization chambers and the absorbed dose is dependent on the beam quality value of the photon beam. For high energy photons, the beam quality is specified by the tissue phantom ratio (TPR 20,10 ) and it is therefore necessary to know the TPR 20,10 to calculate the dose delivered by a given accelerator. This parameter is obtained through the ratio of the absorbed dose at 20 and 10 cm depths in water and was measured in the particular conditions of the tomotherapy accelerator. Afterward, measurements were performed using the ionization chamber (model A1SL) delivered as a reference instrument by the vendor. This chamber is traceable in absorbed dose to water in a Co-60 beam to a water calorimeter of the American metrology institute (NIST). Similarly, in Switzerland, each radiotherapy department is directly traceable to the Swiss metrology institute (METAS) in absorbed dose to water based on a water calorimeter. For our research, this traceability was obtained by using an ionization chamber traceable to METAS (model NE 2611A), which is the secondary standard of our institute. Furthermore, in order to have another fully independent measurement method, we determined the dose using alanine dosimeters provided by and traceable to the British metrology institute (NPL); they are calibrated in absorbed dose to water using a graphite calorimeter. And finally, we wanted to take into account the type of chamber routinely used in clinical practice and

  20. Nondestructive examination techniques on Candu fuel elements

    International Nuclear Information System (INIS)

    Gheorghe, G.; Man, I.

    2013-01-01

    During irradiation in nuclear reactor, fuel elements undergo dimensional and structural changes, and changes of surface conditions sheath as well, which can lead to damages and even loss of integrity. Visual examination and photography of Candu fuel elements are among the non-destructive examination techniques, next to dimensional measurements that include profiling (diameter, bending, camber) and length, sheath integrity control with eddy currents, measurement of the oxide layer thickness by eddy current techniques. Unirradiated Zircaloy-4 tubes were used for calibration purposes, whereas irradiated Zircaloy-4 tubes were actually subjected to visual inspection and dimensional measurements. We present results of measurements done by eddy current techniques on Zircaloy- 4 tubes, unirradiated, but oxidized in an autoclave prior to examinations. The purpose of these nondestructive examination techniques is to determine those parameters that characterize the behavior and performance of nuclear fuel operation. (authors)

  1. The European conference on nondestructive testing

    International Nuclear Information System (INIS)

    Klyuev, V.V.

    1985-01-01

    Information on the 3-d European conference on nondestructive testing (NT) held in October, 1984 in Florence, is presented. Plenary reports were devoted to complex use of different NT methods, tendencies to NT automation and robotics, transition from defectoscopy to quality control, determination of phisico-mechanical properties of items using different control methods, formulation of unified international programs on professional training and qualification. Section reports cover the following directions: NT use in aviation and astronautics, construction, welding engineering, studying works of art; personnel training, economics, NT functioning, automation, calibration, standardization, quality control over metallic and nonmetallic objects. Some reports concerned nondestructive testing of items during their use. Attention is paied to radiographic testing and neutron radiography as well as to image processing. NT equipment was also discussed

  2. Determination optimum dose gamma ray for make mutation in Banana explant (Musa spp. Var cavendish)

    International Nuclear Information System (INIS)

    Goorchini, H.; Nematzadeh, Gh. A.; Majd, F.; Rahimi, M.

    2006-01-01

    Banana belongs to Musaceae family and Musa genus, categorized as a plant growing in tropical and subtropical regions. In recent years, many attempts have been made for extending the cultivation of this plant in Iran. The cultivars, which are cultivating commonly in Iran are mostly Cavendish and Grand Nain, having rather long heights (2-4 meters). This research has been carried out aiming at determining the optimum dose rate to induce mutation in the banana plant shoot-tips. For this purpose the plant shoot-tips were exposed to various doses of gamma radiation with eight treatments of 0, 10, 15, 20, 25, 35, 45 and 60 Gray. The project was directed in a completely randomized design. After the treatment, various traits such as: number of alive plants, number of leafs, plant height and wet weight have been measured. For the data analysis, SAS and MSTAT softwares have been used in order to evaluate the average values and variances of the output results for the further analysis and comparisons. The results indicate that the dose rates of 25 to 40 Gray are the optimum rate values for induction of the mutation in this plant. Also, the propit analysis shows that the dose rate of 39.8 Gray is at the point of LD50 (50% of the dead level)

  3. Quantitative determination of circulating endothelial cells in persons with low dose radioactivity exposure

    International Nuclear Information System (INIS)

    Al-Massarani, Gh.; Najjar, F.

    2013-04-01

    The aim of this study was to determine the risk of occupational exposure to low doses of ionizing radiation on the endothelium detachment through the quantification of circulating endothelial cells (CEC) in the peripheral blood of 63 workers in the Atomic Energy Commission in Syria (AECS) using a Magnetic Immuno-separation technique (IMS) and compare the results with 28 healthy (controls) is not exposed during their careers for any type of ionizing radiation. Our study showed for the first time the significantly increasing in the circulating endothelial cells count (P <0.0001) when employees are exposed to low doses of radiation less than 50 mSv. This result with previous studies about the late effects of radiation, assuming the existence of impact late radiation exposure on the cohesion of the endothelium, despite the lack of correlation with radiation dose measured during the past four years of work in AECS (between 2006-2010). This is due to several reasons, including the small sample size and lack of commitment by some workers develop individual control films during some periods of their work. The prospective studies for such workers can allow us to know if the rise in the number of CEC will be considered an early indicator for the risk of a cardiovascular disease when workers exposed to low-doses of ionizing radiation( tens of millisievert) that up to date are considered harmless (author).

  4. Industrial strategy for nondestructive control

    International Nuclear Information System (INIS)

    Martin, P.; Michaut, J.P.

    1994-01-01

    For Electricite de France, the nondestructive control strategy passes by a responsibility of services, a competition between companies, a clarification of the market access and a dialogue with the companies

  5. Radioactivity determination of sealed pure beta-sources by surface dose measurements and Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chang Heon [Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jung, Seongmoon [Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of); Choi, Kanghyuk; Son, Kwang-Jae; Lee, Jun Sig [Hanaro Applications Research, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Ye, Sung-Joon, E-mail: sye@snu.ac.kr [Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul (Korea, Republic of); Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of); Center for Convergence Research on Robotics, Advance Institutes of Convergence Technology, Seoul National University, Suwon (Korea, Republic of)

    2016-04-21

    This study aims to determine the activity of a sealed pure beta-source by measuring the surface dose rate using an extrapolation chamber. A conversion factor (cGy s{sup −1} Bq{sup −1}), which was defined as the ratio of surface dose rate to activity, can be calculated by Monte Carlo simulations of the extrapolation chamber measurement. To validate this hypothesis the certified activities of two standard pure beta-sources of Sr/Y-90 and Si/P-32 were compared with those determined by this method. In addition, a sealed test source of Sr/Y-90 was manufactured by the HANARO reactor group of KAERI (Korea Atomic Energy Research Institute) and used to further validate this method. The measured surface dose rates of the Sr/Y-90 and Si/P-32 standard sources were 4.615×10{sup −5} cGy s{sup −1} and 2.259×10{sup −5} cGy s{sup −1}, respectively. The calculated conversion factors of the two sources were 1.213×10{sup −8} cGy s{sup −1} Bq{sup −1} and 1.071×10{sup −8} cGy s{sup −1} Bq{sup −1}, respectively. Therefore, the activity of the standard Sr/Y-90 source was determined to be 3.995 kBq, which was 2.0% less than the certified value (4.077 kBq). For Si/P-32 the determined activity was 2.102 kBq, which was 6.6% larger than the certified activity (1.971 kBq). The activity of the Sr/Y-90 test source was determined to be 4.166 kBq, while the apparent activity reported by KAERI was 5.803 kBq. This large difference might be due to evaporation and diffusion of the source liquid during preparation and uncertainty in the amount of weighed aliquot of source liquid. The overall uncertainty involved in this method was determined to be 7.3%. We demonstrated that the activity of a sealed pure beta-source could be conveniently determined by complementary combination of measuring the surface dose rate and Monte Carlo simulations.

  6. Age and dose as determinants of times of appearance of radium-induced osteosarcomas in humans

    International Nuclear Information System (INIS)

    Stebbings, J.H.; Lucas, H.F.

    1983-01-01

    Determinants of time-until-tumor for bone sarcomas in US radium cases have been reevaluated. For the 57 measured female bone sarcoma cases exposed to 226 Ra and/or 228 Ra, ages at appearance of tumor are more strongly correlated with radium intake doses than are latency periods. Ages at appearance of tumor increase as initial radium intakes decrease. As many lower dose cases were iatrogenic cases exposed in mid-adult life, rather than about age 22 as for the dial worker cases, these results may be artifactual, resulting from an increased susceptability to sarcoma induction at older ages. Alternatively the time of appearance of a sarcoma may be in part directly determined by age. Both explanations find support in the literature. These results suggest that 226 228 Ra-induced bone sarcomas do have an expression period. The downturn in sarcoma incidence at very high doses may result from truncation of the expression period on its early side by the minimum induction period

  7. Nondestructive Testing with Shearography

    International Nuclear Information System (INIS)

    Chang, Seog Weon

    2001-01-01

    Nondestructive testing(NDT) is one of the fundamental tools to improve the quality of commercial and industrial products. NDT is potentially a major application of interferometry. Interferometry(ESPI, Shearography, ect) has successfully been applied in various industrial environments such as high performance aircraft, home appliance, automotive, and laminates on engine structures, etc. Today's industry demands high performance components with toughest mechanical features and ultimate safety standards. Especially in automotive and aircraft industry the development process focuses on tailor-made design and solutions to meet customer specifications. To reconcile economy, ligh-weight construction has become a key issue. Many companies are looking for new advanced NDT techniques to archive cost efficiency over the limitations of classical methods. ESPI and shearography allow a rapid, full field and 3D-measurement without contact. In this paper recent applications of ESPI and shearography for NDT are described. Advanced features of classical techniques are specified and new applications in material and component testing are presented

  8. Lifestyle and age as determinates of intake and dose from inhaled radionuclides

    International Nuclear Information System (INIS)

    Fields, D.E.; Yalcintas, M.G.

    1989-01-01

    The whole-body dose from inhaled radionuclides is a complex function of factors describing exposure and physiology. Exposure-related factors may be estimated by considering likely emission rates combined with measured time-varying meteorological (transport) parameters and estimated exercise patterns. Physiological factors, strongly influencing radionuclide intake and consequent radiation dose, have been catalogued as functions of age and activity level. Both exercise patterns and physiological factors are related to age of the exposed individual. Combining these factors permits estimates to be made of the span of exposures that may be expected in a typical population. The ratio of highest to lowest radionuclide intake is predicted to be of the order of 40, suggesting that specification of an 'average' value may be misleading if this value approaches regulatory limits. Individuals exposed to maximal risk may be identified, and are likely to be active children. Activity pattern (lifestyle) is a primary determinant of risk. (author)

  9. Determination of the minimal phototoxic dose and colorimetry in psoralen plus ultraviolet A radiation therapy.

    Science.gov (United States)

    Kraemer, Cristine Kloeckner; Menegon, Dóris Baratz; Cestari, Tania Ferreira

    2005-10-01

    The use of an adequate initial dose of ultraviolet A (UVA) radiation for photochemotherapy is important to prevent burns secondary to overdosage, meanwhile avoiding a reduced clinical improvement and long-term risks secondary to underdosage. The ideal initial dose of UVA can be achieved based on the phototype and the minimal phototoxic dose (MPD). The objective measurement of constitutive skin color (colorimetry) is another method commonly used to quantify the erythematous skin reaction to ultraviolet radiation exposure. The aim of this study was to determine variations in MPD and constitutional skin color (coordinate L(*)) within different phototypes in order to establish the best initial dose of UVA radiation for photochemotherapy patients. Thirty-six patients with dermatological conditions and 13 healthy volunteers were divided into five groups according to phototype. Constitutional skin color of the infra-axillary area was assessed by colorimetry. The infra-axillary area was subsequently divided into twelve 1.5 cm(2) regions to determine the MPD; readings were performed 72 h after oral administration of 8-methoxypsoralen (MOP) followed by exposure of the demarcated regions to increasing doses of UVA. The majority of the participants were women (73.5%) and their mean age was 38.8 years. The MPD ranged from 4 to 12 J/cm(2) in phototypes II and III; from 10 to 18 J/cm(2) in type IV; from 12 to 24 J/cm(2) in type V and from 18 to 32 J/cm(2) in type VI. The analysis of colorimetric values (L(*) coordinate) and MPD values allowed the definition of three distinctive groups of individuals composed by phototypes II and III (group 1), types IV and V (group 2), and phototype VI (group 3). MPD and L(*) coordinate showed variation within the same phototype and superposition between adjacent phototypes. The values of the L(*) coordinate and the MPD lead to the definition of three distinct sensitivity groups: phototypes II and III, IV and V and type VI. Also, the MPD values

  10. Developing point of care and high-throughput biological assays for determining absorbed radiation dose

    International Nuclear Information System (INIS)

    Joiner, Michael C.; Thomas, Robert A.; Grever, William E.; Smolinski, Joseph M.; Divine, George W.; Konski, Andre A.; Auner, Gregory W.; Tucker, James D.

    2011-01-01

    Background and purpose: Systems are being developed to assess radiation exposure based on leukocyte mRNA levels obtained by finger-stick sampling. The goal is to provide accurate detection of dose exposures up to 10 Gy for up to 1 week following exposure. We previously showed that specific mRNA sequences increase expression within an hour of exposure, and some genes continue to show elevated expression for at least 24 h. Full duration and dose-dependence of this persistence remain to be determined. In the present study, real-time quantitative PCR (qPCR) was used to determine changes in gene expression. qPCR can rapidly analyze small blood samples and could be adopted into a field-portable instrument that provides a radiation dose readout within 30 min. Materials and methods: From previous microarray analysis of 21,000 genes expressed in human lymphoblastoid cells 4 h post-irradiation (0–4 Gy), 118 genes were selected for evaluation by qPCR of gene expression in the leukocytes of human blood irradiated in vitro with doses of 0–10 Gy from a Co-60 gamma source at a dose rate of 30 cGy/min. Results: Blood from 20 normal healthy human donors yielded many mRNA sequences that could be used for radiation dosimetry. We observed four genes with large and persistent responses following exposure: ASTN2, CDKN1A, GADD45A, and GDF15. Five genes were identified as reliably non-responsive and were suitable for use as endogenous controls: DPM1, ITFG1, MAP4, PGK1, and SLC25A36; of these, ITFG1 was used for the analyses presented here. A significant dose-responsive increase in expression occurred for CDKN1A that was >16-fold at 10 Gy and 3-fold at 0.5 Gy compared to pre-irradiation values. Conclusions: These data show large, selective increases in mRNA transcript levels that persist for at least 48 h after single exposures between 0.5 and 10 Gy. Stable, non-responsive mRNA sequences for use as endogenous controls were also identified. These results indicate that following further

  11. Numerical simulation of a TLD pulsed laser-heating scheme for determination of shallow dose and deep dose in low-LET radiation fields

    International Nuclear Information System (INIS)

    Kearfott, K.J.; Han, S.; Wagner, E.C.; Samei, E.; Wang, C.-K.C.

    2000-01-01

    A new method is described to determine the depth-dose distribution in low-LET radiation fields using a thick thermoluminescent dosimeter (TLD) with a pulsed laser-heating scheme to obtain TL glow output. The computational simulation entails heat conduction and glow curve production processes. An iterative algorithm is used to obtain the dose distribution in the detector. The simulation results indicate that the method can predict the shallow and deep dose in various radiation fields with relative errors less than 20%

  12. A photon spectrometric dose-rate constant determination for the Advantage Pd-103 brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhe Jay; Bongiorni, Paul; Nath, Ravinder [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 (United States)

    2010-02-15

    Purpose: Although several dosimetric characterizations using Monte Carlo simulation and thermoluminescent dosimetry (TLD) have been reported for the new Advantage Pd-103 source (IsoAid, LLC, Port Richey, FL), no AAPM consensus value has been established for the dosimetric parameters of the source. The aim of this work was to perform an additional dose-rate constant ({Lambda}) determination using a recently established photon spectrometry technique (PST) that is independent of the published TLD and Monte Carlo techniques. Methods: Three Model IAPD-103A Advantage Pd-103 sources were used in this study. The relative photon energy spectrum emitted by each source along the transverse axis was measured using a high-resolution germanium spectrometer designed for low-energy photons. For each source, the dose-rate constant was determined from its emitted energy spectrum. The PST-determined dose-rate constant ({sub PST}{Lambda}) was then compared to those determined by TLD ({sub TLD}{Lambda}) and Monte Carlo ({sub MC}{Lambda}) techniques. A likely consensus {Lambda} value was estimated as the arithmetic mean of the average {Lambda} values determined by each of three different techniques. Results: The average {sub PST}{Lambda} value for the three Advantage sources was found to be (0.676{+-}0.026) cGyh{sup -1} U{sup -1}. Intersource variation in {sub PST}{Lambda} was less than 0.01%. The {sub PST}{Lambda} was within 2% of the reported {sub MC}{Lambda} values determined by PTRAN, EGSnrc, and MCNP5 codes. It was 3.4% lower than the reported {sub TLD}{Lambda}. A likely consensus {Lambda} value was estimated to be (0.688{+-}0.026) cGyh{sup -1} U{sup -1}, similar to the AAPM consensus values recommended currently for the Theragenics (Buford, GA) Model 200 (0.686{+-}0.033) cGyh{sup -1} U{sup -1}, the NASI (Chatsworth, CA) Model MED3633 (0.688{+-}0.033) cGyh{sup -1} U{sup -1}, and the Best Medical (Springfield, VA) Model 2335 (0.685{+-}0.033) cGyh{sup -1} U{sup -1} {sup 103}Pd

  13. A photon spectrometric dose-rate constant determination for the Advantage Pd-103 brachytherapy source

    International Nuclear Information System (INIS)

    Chen, Zhe Jay; Bongiorni, Paul; Nath, Ravinder

    2010-01-01

    Purpose: Although several dosimetric characterizations using Monte Carlo simulation and thermoluminescent dosimetry (TLD) have been reported for the new Advantage Pd-103 source (IsoAid, LLC, Port Richey, FL), no AAPM consensus value has been established for the dosimetric parameters of the source. The aim of this work was to perform an additional dose-rate constant (Λ) determination using a recently established photon spectrometry technique (PST) that is independent of the published TLD and Monte Carlo techniques. Methods: Three Model IAPD-103A Advantage Pd-103 sources were used in this study. The relative photon energy spectrum emitted by each source along the transverse axis was measured using a high-resolution germanium spectrometer designed for low-energy photons. For each source, the dose-rate constant was determined from its emitted energy spectrum. The PST-determined dose-rate constant ( PST Λ) was then compared to those determined by TLD ( TLD Λ) and Monte Carlo ( MC Λ) techniques. A likely consensus Λ value was estimated as the arithmetic mean of the average Λ values determined by each of three different techniques. Results: The average PST Λ value for the three Advantage sources was found to be (0.676±0.026) cGyh -1 U -1 . Intersource variation in PST Λ was less than 0.01%. The PST Λ was within 2% of the reported MC Λ values determined by PTRAN, EGSnrc, and MCNP5 codes. It was 3.4% lower than the reported TLD Λ. A likely consensus Λ value was estimated to be (0.688±0.026) cGyh -1 U -1 , similar to the AAPM consensus values recommended currently for the Theragenics (Buford, GA) Model 200 (0.686±0.033) cGyh -1 U -1 , the NASI (Chatsworth, CA) Model MED3633 (0.688±0.033) cGyh -1 U -1 , and the Best Medical (Springfield, VA) Model 2335 (0.685±0.033) cGyh -1 U -1 103 Pd sources. Conclusions: An independent Λ determination has been performed for the Advantage Pd-103 source. The PST Λ obtained in this work provides additional information

  14. Set of programs for determining exposure and dose rates from selected sources of gamma radiation

    International Nuclear Information System (INIS)

    Hep, J.; Kralovcova, E.; Smutny, V.; Valenta, V.

    1982-01-01

    The programs are described for the determination of exposure and dose rate of gamma radiation from point, surface, linear and volume sources with and without shielding. The computation is conducted using the classical method taking into consideration the buildup factor. For the computation of the buildup factor in heterogeneous shielding the Broder and Kitazuma formulas are used. Kitazuma's alpha coefficients were calculated recurrently using a new semi-empirical method. Taylor's approximation was used for the calculation of the buildup factor in a single layer

  15. Determination of the energy dose of a neutron beam using a ionization chamber. A compendium

    International Nuclear Information System (INIS)

    Schraube, H.; Alberts, W.G.; Brede, H.; Burgkhardt, B.; Piesch, E.; Doerschel, B.; Heinzelmann, M.; Hess, A.; Hoefert, M.

    2003-01-01

    This report is addressed to scientists and technicians, who are engaged in dosimetry of fast neutrons, especially for purposes of percutaneous radiation therapy. The range of mean energies of the radiation sources may be approximately between 1 MeV and 50 MeV. The report exhibits a compendium, which describes the basic methods and procedures for the determination of energy dose in tissue in a phantom or free-in-air, where applicable. Furthermore, requirements for monitor, test devices and phantom materials are described. The calculation methods are comprehensibly derived and supplemented with numerical data. A detailed analysis of experimental uncertainties is completed with practical examples. (orig.) [de

  16. Preliminary field dose rate determination in the environment of the Paks nuclear power plant

    International Nuclear Information System (INIS)

    Nemeth, I.; Zombori, P.; Koblinger, L.; Andrasi, A.; Deme, S.

    1983-01-01

    The in situ measurements were performed by a NaI(Tl) scintillation spectrometer and a GM detector at 23 points in the environment of the power plant. During the sophisticated calibration procedure the energy and direction dependences of the detector responses were also taken into account. The dose rates were also determined by the POKER-CAMP computer code for natural radionuclides with an assumed source distribution. On the basis of the good agreement between the measured and calculated values the sensitivity of the measuring system was assessed for some given distributed radionuclides released from the power plant. (author)

  17. Determinations of dose mean of specific energy for conventional x-rays by variance-measurements

    International Nuclear Information System (INIS)

    Forsberg, B.; Jensen, M.; Lindborg, L.; Samuelson, G.

    1978-05-01

    The dose mean value (zeta) of specific energy of a single event distribution is related to the variance of a multiple event distribution in a simple way. It is thus possible to determine zeta from measurements in high dose rates through observations of the variations in the ionization current from for instance an ionization chamber, if other parameters contribute negligibly to the total variance. With this method is has earlier been possible to obtain results down to about 10 nm in a beam of Co60-γ rays, which is one order of magnitude smaller than the sizes obtainable with the traditional technique. This advantage together with the suggestion that zeta could be an important parameter in radiobiology make further studies of the applications of the technique motivated. So far only data from measurements in beams of a radioactive nuclide has been reported. This paper contains results from measurements in a highly stabilized X-ray beam. The preliminary analysis shows that the variance technique has given reasonable results for object sizes in the region of 0.08 μm to 20 μm (100 kV, 1.6 Al, HVL 0.14 mm Cu). The results were obtained with a proportional counter except for the larger object sizes, where an ionization chamber was used. The measurements were performed at dose rates between 1 Gy/h and 40 Gy/h. (author)

  18. The Non-Destructive Determination of Burn-Up by Means of the Prl44 2.18 M Gamma Activity

    International Nuclear Information System (INIS)

    Forsyth, R.S.; Blackadder, W.H.

    1965-05-01

    In recent years, gamma scanning has been used at several establishments for the determination of the burn-up profile along irradiated fuel elements, the 0.75 MeV gamma from Zr-95/Nb-95 being most often employed as the monitored radiation. Difficulties in establishing the geometry and the self-absorption of the gamma activity in the fuel have tended to prevent the application of the method to quantitative burn-up determination, which has usually been carried out by dissolution of selected portions of the fuel followed by conventional fission product separation or by uranium depletion methods. The present paper describes experiments carried out to calibrate a gamma scanner for quantitative measurements by counting the 2.18 MeV gamma activity due to Pr-144, the short-lived daughter of Ce-144 (t 1/2 = 285 days) from selected pellets in several UO 2 fuel specimens. Accurate burn-up values were then determined by dissolution and application of the isotopic dilution method, using stable molybdenum fission products. The elements, which were rotated about their longitudinal axes to minimize asymmetry effects, were viewed by a sodium iodide crystal and a multichannel analyser through a suitable collimator. Correction for attenuation of the gamma activity (much less than for 0.75 MeV) in the fuel elements which were of different diameters (12.6 to 15.04 mm) was made by applying relative attenuation factors and the effective geometry factor of the instrument was determined. In order to check the corrections applied, the counter factor was also calculated, for the 0.75 MeV activity from Zr-95/Nb-95 and in certain cases for the 0.66 MeV activity from Cs-137. The results obtained, demonstrate that at least over the range of diameters and cooling times used the method is suitable for quantitative determinations. Preliminary experiments to explore the possibility of using the high energy gammas (2.35, 2.65 MeV) from Rh-106 as a method for estimating the fraction of fission events

  19. The Non-Destructive Determination of Burn-Up by Means of the Pr{sup l44} 2.18 M Gamma Activity

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R S; Blackadder, W H

    1965-05-15

    In recent years, gamma scanning has been used at several establishments for the determination of the burn-up profile along irradiated fuel elements, the 0.75 MeV gamma from Zr-95/Nb-95 being most often employed as the monitored radiation. Difficulties in establishing the geometry and the self-absorption of the gamma activity in the fuel have tended to prevent the application of the method to quantitative burn-up determination, which has usually been carried out by dissolution of selected portions of the fuel followed by conventional fission product separation or by uranium depletion methods. The present paper describes experiments carried out to calibrate a gamma scanner for quantitative measurements by counting the 2.18 MeV gamma activity due to Pr-144, the short-lived daughter of Ce-144 (t{sub 1/2} = 285 days) from selected pellets in several UO{sub 2} fuel specimens. Accurate burn-up values were then determined by dissolution and application of the isotopic dilution method, using stable molybdenum fission products. The elements, which were rotated about their longitudinal axes to minimize asymmetry effects, were viewed by a sodium iodide crystal and a multichannel analyser through a suitable collimator. Correction for attenuation of the gamma activity (much less than for 0.75 MeV) in the fuel elements which were of different diameters (12.6 to 15.04 mm) was made by applying relative attenuation factors and the effective geometry factor of the instrument was determined. In order to check the corrections applied, the counter factor was also calculated, for the 0.75 MeV activity from Zr-95/Nb-95 and in certain cases for the 0.66 MeV activity from Cs-137. The results obtained, demonstrate that at least over the range of diameters and cooling times used the method is suitable for quantitative determinations. Preliminary experiments to explore the possibility of using the high energy gammas (2.35, 2.65 MeV) from Rh-106 as a method for estimating the fraction of

  20. Radiation sterilisation dose determination for lyophilised amnion membranes and lyophilised bone grafts

    International Nuclear Information System (INIS)

    Hilmy, N.; Basril, A.; Febrida, A.

    1999-01-01

    Radiation sterilisation of medical products is now well established in commercial scale and at present there are more than two hundred irradiation facilities in operation throughout the world. It is a cold sterilisation process without toxic chemical residues, high degree of safety and easy to control, so that it is a safe technology to sterilise human tissue grafts. According to ISO (International Organisation of Standard) No. 11137, radiation sterilisation dose should be established based on the number of product's bioburden (number of product's contaminated microbes before irradiation). Bioburden of lyophilised amnion membranes and lyophilised bone grafts produced by Batan Research Tissue Bank (BRTB) have been determined since 1990 and 1994 consecutively by using 100 up to 120 pieces of samples per year. Results show that the average bioburden of the amnion membranes were 1.4 ( 0.2 x 103; 1.2 (0.2 x 103; 1.2 ( 1.2 x 103; 4.5 ( 0.5 x 102; 1.8 ( 0.9 x 102; 2.4 ( 2.3 x 102; 1.7(l.5 x 102; 1.5 ( 1.7 x 102 cells per sample, calculated in 1990 to 1997 consecutively and the average bioburden of the bonegrafts were 1.5 (0.4x 101; 0.25 (0.12 x 101; 0; 0 cells per sample, calculated in 1994 to 1997 consecutively. Morphological of those contaminants were found to be Gram positive coccoid forms (98%) and Gram positive vegetative rod (2%) with the D10 - values of 0.25 to 0.50 kGy. No spore forming bacteria and Gram negative bacteria were found in those contaminations. The highest bioburden of lyophilised amnion membranes and lyophilised bone grafts were found to be 4900 and 80 cells per sample consecutively, and the lowest was found to be 0 cell per sample in both of materials observed. According to ISO 11137 radiation sterilisation doses for amnion membranes were ranging between 21 to 25 kGy and for bone grafts was around 15 kGy with the Sterility Assurance Level (SAL) of 106. Since 1990, radiation sterilisation dose used for lyophilised amnion membranes produced by BRTB

  1. Isolation time determination of patients with differentiated thyroid carcinoma treated with therapeutic doses of 131 radioiodine

    International Nuclear Information System (INIS)

    Sierralta, M.P.; Lillo, R.; Massardo, T.; Jofre, M.J.

    2002-01-01

    Isolation time determination of patients with differentiated thyroid carcinoma treated with therapeutic doses of 131 radioiodine. Introduction: The coadyuvant treatment with 131 I had proven to be useful in patients with differentiated thyroid carcinoma (DTC). Due to the physical characteristics of this radioisotope these patients must be absolutely isolated in order to reduce the radioactive exposure to other individuals. The aim of the study was to determine the time required to reach the maximum permissible radiation exposure level (0,25mR/h) to general public. Material between August 1999 and May 2000, 30 patients with DTC diagnosis in the University of Chile Clinical Hospital Nuclear Medicine Centre were studied, 25 women (83%) and 5 men (17%), mean age 45 years old (15-71 range). Tumoral histology was 86% papillary and 14% follicular types. Thirty one doses of 131 I were administered ( one patient received 2 doses): 24 of 100 mCi (77%), 5 of 150 mCi (16%) and 2 of 200 mCi (7%); afterwards the 1 m exposition rate in air was measured at neck level with a Geiger-Mueller detector. The procedure was repeated on day 4 and every day following until the predicted radiation exposure levels were reached. Results: The average exposure rate at day 0 ( after given the radiopharmaceutical) was 20,12 mR/h (4-32 range). At day 4 the average rate was 0,21 mR/h (0,08-0,34 ), and 61% (n=19) of the patients reached 0,25 mR/h within that day. On day 5 10% (n=3) reached 0,25 mR/h (0,25-0,26), on day 6 16% (n=5) reached 0,25 mR/h (0,2-0,28), on day 7 6% (n=2) reached 0,39 mR/h (0,25-0,48) and the remaining 7% on day 13 and day 17 (n=2). Conclusion After a treatment dose of 131 iodine over 60% of the cases can finish the isolation on day 4, and 90% on day 7. The measurement of 131 I uptake after 24 hours will help to determine the evolution of post treatment levels

  2. Isolation time determination of patients with differentiated thyroid carcinoma treated with therapeutic doses of 131 radioiodine

    Energy Technology Data Exchange (ETDEWEB)

    Sierralta, M P [University of Chile Clinical Hospital Nuclear Medicine Centre, Santiago (Chile); Military Hospital Nuclear Medicine Department , Santiago (Chile); Lillo, R; Massardo, T [University of Chile Clinical Hospital Nuclear Medicine Centre, Santiago (Chile); Jofre, M J [Military Hospital Nuclear Medicine Department, Santiago (Chile)

    2002-09-01

    Isolation time determination of patients with differentiated thyroid carcinoma treated with therapeutic doses of 131 radioiodine. Introduction: The coadyuvant treatment with 131 I had proven to be useful in patients with differentiated thyroid carcinoma (DTC). Due to the physical characteristics of this radioisotope these patients must be absolutely isolated in order to reduce the radioactive exposure to other individuals. The aim of the study was to determine the time required to reach the maximum permissible radiation exposure level (0,25mR/h) to general public. Material between August 1999 and May 2000, 30 patients with DTC diagnosis in the University of Chile Clinical Hospital Nuclear Medicine Centre were studied, 25 women (83%) and 5 men (17%), mean age 45 years old (15-71 range). Tumoral histology was 86% papillary and 14% follicular types. Thirty one doses of 131 I were administered ( one patient received 2 doses): 24 of 100 mCi (77%), 5 of 150 mCi (16%) and 2 of 200 mCi (7%); afterwards the 1 m exposition rate in air was measured at neck level with a Geiger-Mueller detector. The procedure was repeated on day 4 and every day following until the predicted radiation exposure levels were reached. Results: The average exposure rate at day 0 ( after given the radiopharmaceutical) was 20,12 mR/h (4-32 range). At day 4 the average rate was 0,21 mR/h (0,08-0,34 ), and 61% (n=19) of the patients reached 0,25 mR/h within that day. On day 5 10% (n=3) reached 0,25 mR/h (0,25-0,26), on day 6 16% (n=5) reached 0,25 mR/h (0,2-0,28), on day 7 6% (n=2) reached 0,39 mR/h (0,25-0,48) and the remaining 7% on day 13 and day 17 (n=2). Conclusion After a treatment dose of 131 iodine over 60% of the cases can finish the isolation on day 4, and 90% on day 7. The measurement of 131 I uptake after 24 hours will help to determine the evolution of post treatment levels.

  3. Determination of subcellular compartment sizes for estimating dose variations in radiotherapy

    International Nuclear Information System (INIS)

    Poole, Christopher M.; Ahnesjo, Anders; Enger, Shirin A.

    2015-01-01

    The variation in specific energy absorbed to different cell compartments caused by variations in size and chemical composition is poorly investigated in radiotherapy. The aim of this study was to develop an algorithm to derive cell and cell nuclei size distributions from 2D histology samples, and build 3D cellular geometries to provide Monte Carlo (MC)-based dose calculation engines with a morphologically relevant input geometry. Stained and unstained regions of the histology samples are segmented using a Gaussian mixture model, and individual cell nuclei are identified via thresholding. Delaunay triangulation is applied to determine the distribution of distances between the centroids of nearest neighbour cells. A pouring simulation is used to build a 3D virtual tissue sample, with cell radii randomised according to the cell size distribution determined from the histology samples. A slice with the same thickness as the histology sample is cut through the 3D data and characterised in the same way as the measured histology. The comparison between this virtual slice and the measured histology is used to adjust the initial cell size distribution into the pouring simulation. This iterative approach of a pouring simulation with adjustments guided by comparison is continued until an input cell size distribution is found that yields a distribution in the sliced geometry that agrees with the measured histology samples. The thus obtained morphologically realistic 3D cellular geometry can be used as input to MC-based dose calculation programs for studies of dose response due to variations in morphology and size of tumour/healthy tissue cells/nuclei, and extracellular material. (authors)

  4. Dose determination of Neutron contamination in radiothrapy rooms equiped with high energy linear accelerators

    International Nuclear Information System (INIS)

    Shweikani, R.; Anjak, O.

    2014-03-01

    Radiotherapy represents the most widely spread technique to control and treat cancer. To increase the treatment efficiency, high-energy linear accelerators are used. However, applying high energy photon beams leads to a non-negligible dose of neutrons contaminating therapeutic beams. A high-energy (23 MV) linear accelerator (Varian 21EX) was studied. The CR-39 nuclear track detectors (NTDs) were used to study the variation of fast neutron relative intensities around a linear accelerator high energy photon beam and to determined the its variation on the patient plane at 0, 50, 100, 150 and 200 cm from the center of the photon beam was. By increasing the distance from the center of the X-ray beam towards the periphery, the photoneutron dose equivalent decreased rapidly for the fields. Photoneutron intensity and distributions at isocenter level with the field sizes of 40*40 cm'2 at SSD=100cm around 23 MV photon beam using Nuclear Track Detectors were determined. The advantages of CR-39 NTD s over active detectors: 1- there is no pulse pileup problem. 2- no photon interference with neutron measurement. 3- no electronics are required. 4 - less prone to noise and interference. The photoneutron intensities were rapidly decreased as we move away from the isocenter of linear accelerators. As the use of simulation software MCNP match in the results we have obtained through direct measurements and the modeling results using the code MCNP (author).

  5. Using ionising radiation against terrorism and contrabandage determination of the occurring dose values

    International Nuclear Information System (INIS)

    Hupe, O.; Ankerhold, U.

    2006-01-01

    Full text of publication follows: Presently the combat against terrorism and contrabandage is gaining in importance. This leads to a growing need for human inspections for weapons or chemical substances like drugs or explosives at e.g. airports and federal buildings. Up to now, this has been done mainly by pat search or the use of metal detectors. But the installed metal detection systems can have a high rate of false alerts, caused e.g. by belt buckles, leading to a high rate of time consuming manual follow-up checks. Also, it is not possible to detect chemical substances or modern plastic weapons. Therefore, a lot of efforts have been made to develop reliable technologies for passenger and cargo controls. Up to now, the demands placed on control systems for the use in routine are fulfilled only by X-ray screening systems. X-ray scanners have been used successfully for several years for personnel controls (checks) at diamond mines and prisons or as cargo scanner. So far, however, these systems have not been used frequently for human inspections, e.g. at airports. In general, two aspects must be considered wit h regard to the use of X-ray personnel scanners: the privacy aspect, because the body shape is seen, and the radiation protection aspect. For radiation protection purposes, and to observe the prescribed dose limits, it is extremely important to know the dose a person gets knowingly when passing a personnel scanner or, as a stowaway, a cargo scanner. Within the scope of a research project measurements were performed on different types of personnel and cargo scanners, using the transmission and backscattering method. All scanners investigated work with a high dose rate and use a short irradiation time. Because of this technique, reliable values of the personal and ambient dose equivalent, H p (10) and H * (10), could be determined only with a specially developed measuring system (presented in a poster at this conference). The scanner systems and dose values

  6. Determination of the irradiation dose for the inhibition (D-10 radiation doses) of some gram negative and gram positive bacteria in peptone saline water

    International Nuclear Information System (INIS)

    Ayhan, H.; Tutluer, H.

    1994-01-01

    Determination of the irradiation dose for the inhibition of some pathogenic bacteria which cause food poisoning and spoilage were aimed. For this purpose, Salmonella typhi, Salmonella typhimurium,Salmonella enteridits,Klebsiella pneumonia, Pseudomonas fluorescence,Proteus vulgaris, Aeromonas hydrophila ,(gram-negative bacteria) and Bacillus cereus, Staphylococcus aureus strain 24,Staphylococcus aureus ATCC 6538 P,Staphylococcus epidermidis strain 115 and Clostridium perfringens A4TTK,(gram-positive bacteria) were used.Sensitivity of above mentioned bacteria to gamma rays (source Cs-137) was examined in saline with 0.1% peptone at different temperatures.Survivor plots (log.10 number of survivors versus dose) were determined by regression analysis of the data.Decimal reduction doses (D values in kGy) were calculated as the slope obtained from the regression analysis

  7. A Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique and Three Types of Gamma-ray Detectors

    International Nuclear Information System (INIS)

    Navarro, Jorge; Aryaeinejad, Rahmat; Nigg, David W.

    2011-01-01

    Effective and efficient Advanced Test Reactor (ATR) fuel management require state of the art core modeling tools. These new tools will need isotopic and burnup validation data before they are put into production. To create isotopic, burn up validation libraries and to determine the setup for permanent fuel scanner system a feasibility study was perform. The study consisted in measuring short and long cooling time fuel elements at the ATR canal. Three gamma spectroscopy detectors (HPGe, LaBr3, and HPXe) and two system configurations (above and under water) were used in the feasibility study. The first stage of the study was to investigate which detector and system configuration would be better suited for different scenarios. The second stage of the feasibility study was to create burnup and cooling time calibrations using experimental isotopic data collected and ORIGEN 2.2 burnup data. The results of the study establish that a better spectra resolution is achieve with an above the water configuration and that three detectors can be used in the permanent fuel scanner system for different situations. In addition it was conclude that a number of isotopic ratios and absolute measurements could be used to predict ATR fuel burnup and cooling times.

  8. A non-destructive method of determination of biomass of mango (Mangifera indica L.) and guava trees using principle of isotope dilution

    International Nuclear Information System (INIS)

    Kotur, S.C.; Keshava Murthy, S.V.

    2004-01-01

    Biomass of 4-year old trees 'Alphonso' mango was estimated by injecting carrier- free 32 P into the trunk followed by radioassay of the isotope after a complete dilution of 32 P in the tree (3 months after injection). The isotopically calculated plant volume (56.903 - 68.981 m 3 x10 3 ) and biomass (31.70 - 36.23 gx 10 -3 ) showed good agreement but generally overestimated both by about 19 per cent compared to the actual values determined physically (43.720 - 60.693 m 3 x10 3 and 22.88 - 34.78 gx 10 -3 , respectively). Application of the technique in a set of four 15-year old mango trees yielded volume estimates of 170.749 - 175.835 m 3 x10 3 (mean 173.512 ± 1.12 per cent) and biomass estimates of 73.0 - 87.4 gx10 -3 (mean = 80.32 ± 6.79 per cent). In another set of four 12-year old guava trees the corresponding values were 40.165 to 44.014 m 3 x10 3 (mean = 41.743 ± 3.42 per cent) and 22.252 gxl0 -3 (mean = 23.210 ± 2.95 per cent) respectively. The technique is of promise in fertilizer use efficiency and nutrient dynamics studies in tree crops. (author)

  9. Determination of Radiation Absorbed Dose to Primary Liver Tumors and Normal Liver Tissue Using Post Radioembolization 90Y PET

    Directory of Open Access Journals (Sweden)

    Shyam Mohan Srinivas

    2014-10-01

    Full Text Available Background: Radioembolization with Yttrium-90 (90Y microspheres is becoming a more widely used transcatheter treatment for unresectable hepatocellular carcinoma (HCC. Using post-treatment 90Y PET/CT scans,the distribution of microspheres within the liver can be determined and quantitatively assessesed . We studied the radiation dose of 90Y delivered to liver and treated tumors.Methods: This retrospective study of 56 patients with HCC, including analysis of 98 liver tumors, measured and correlated the dose of radiation delivered to liver tumors and normal liver tissue using glass microspheres (TheraSpheres® to the frequency of complications with mRECIST. 90Y PET/CT and triphasic liver CT scans were used to contour treated tumor and normal liver regions and determine their respective activity concentrations. An absorbed dose factor was used to convert the measured activity concentration (Bq/mL to an absorbed dose (Gy.Results: The 98 studied tumors received a mean dose of 169 Gy (mode 90-120 Gy;range 0-570 Gy. Tumor response by mRECIST criteria was performed for 48 tumors that had follow up scans. There were 21 responders (mean dose 215 Gy and 27 nonresponders (mean dose 167 Gy. The association between mean tumor absorbed dose and response suggests a trend but did not reach statistical significance (p=0.099. Normal liver tissue received a mean dose of 67 Gy (mode 60-70 Gy; range 10-120 Gy. There was a statistically significant association between absorbed dose to normal liver and the presence of two or more severe complications (p=0.036.Conclusion: Our cohort of patients showed a possible dose response trend for the tumors. Collateral dose to normal liver is nontrivial and can have clinical implications. These methods help us understand whether patient adverse events, treatment success, or treatment failure can be attributed to the dose which the tumor or normal liver received.

  10. RBE/absorbed dose relationship of d(50)-Be neutrons determined for early intestinal tolerance in mice

    International Nuclear Information System (INIS)

    Gueulette, J.; Wambersie, A.

    1978-01-01

    RBE/absorbed dose relationship of d(50)-Be neutrons (ref.: 60 Co) was determined using intestinal tolerance in mice (LD50) after single and fractionated irradiation. RBE is 1.8 for a single fraction (about 1000 rad 60 Co dose); it increases when decreasing dose and reaches the plateau value of 2.8 for a 60 Co dose of about 200 rad. This RBE value is used for the clinical applications with the cyclotron 'Cyclone' at Louvain-la-Neuve [fr

  11. Determinants of virological outcome and adverse events in African children treated with paediatric nevirapine fixed-dose-combination tablets

    NARCIS (Netherlands)

    Bienczak, A.; Denti, P.; Cook, A.; Wiesner, L.; Mulenga, V.; Kityo, C.; Kekitiinwa, A.; Gibb, D.M.; Burger, D.M.; Walker, A.S.; McIlleron, H.

    2017-01-01

    BACKGROUND: Nevirapine is the only nonnucleoside reverse transcriptase inhibitor currently available as a paediatric fixed-dose-combination tablet and is widely used in African children. Nonetheless, the number of investigations into pharmacokinetic determinants of virological suppression in African

  12. Determination of effective irradiation dose to maintain quality of garlic cultivars during storage

    International Nuclear Information System (INIS)

    Janagam, Venu Madhav; Sethi, Shruti; Kaur, Charanjit; Singh, Bhupinder; Pal, R.K.

    2014-01-01

    Garlic (Allium sativum L.) is the second most widely cultivated allium vegetable next to onion. India is the second largest producer (4.46%) of garlic after China (81.02%). As freshly harvested garlic is available in the market for three to four months and there is urgent need to store huge quantity of garlic to fulfil the demand of the consumers during the off-season. The major causes of losses in garlic are sprouting, physiological loss in weight (PLW), decay and quality loss. Several investigators have proved the efficacy of the use of ionizing radiations to reduce the losses caused due to sprouting and other factors. The aim of the study was to investigate the effect of irradiation on post harvest quality of garlic and to determine the irradiation dose for maximum quality retention. Two garlic varieties namely, Yamuna Safed (G-1) and Yamuna Safed-4 (G-323) were treated 120 days (just after dormancy break) postharvest with different doses of gamma irradiation (0.075, 0.01 and 0.15 kGy) and their quality parameters were studied upto 210 days at ambient conditions (18-32℃ and 55-65% RH). Effect of irradiation on physical, physiological and biochemical parameters during storage of both the varieties of garlic revealed that 0.1 kGy irradiation dose was most significant in checking sprouting, controlling decay, PLW, respiration rate and retention of total soluble solids (TSS), pyruvic acid, antioxidant activity, total phenols and amylase activity during storage in comparison to non-irradiated samples followed by 0.15 and 0.075 kGy. Among the two varieties studied, the variety G-323 performed better than G-1 with regard to changes in physiological and biochemical parameters during storage. (author)

  13. Determination of mean glandular dose on patients and phantom in X-ray mammography

    International Nuclear Information System (INIS)

    Avramova-Cholakova, S.; Vassileva, J.

    2008-01-01

    The statistics of breast cancer rate in Bulgaria show a tendency towards increase of the morbidity from this disease. Last years campaigns against breast cancer are organized yearly. This leads to an increased number of screening and diagnostic mammograms that are made in the country. The dose associated with the examination is very low but not slightingly small. The glandular tissue in the breast is considered to be the most sensitive in relation to the radiation exposure. Several publications propose different methods, measurement set up or conversion coefficients for the calculation of the mean glandular dose (MGD) delivered to the breast during the X-ray examination. The question about the standardization of the measurement procedures arises since the differences in the results obtained using different methodologies may be quite big. The aim of this work is to develop a standard procedure for the measurement of MGD based on the recommendations mentioned in the European protocol on dosimetry in mammography, the European protocol for the quality control of the physical and technical aspects of mammography screening and the Code of practice: TRS 457 of the IAEA. Five contemporary film-screen mammography units were included in this study. Attention should be paid to the measurement set up. The reference point is chosen 6 cm from the chest wall edge laterally centered. If an ionization chamber is used for dose measurements the compression plate should be placed in close contact with it. If solid state detectors are used the compression plate should be put away from the detector and the output recalculated like if the plate is near the detector. The conversion coefficients for age dependence are not used in this study as not appropriate for the population included in it. PMMA measurements for the determination of diagnostic reference levels could be used but more correct results would be obtained with patient measurements

  14. Monte Carlo determination of dose in crystalline and thyroid during chest tomography examinations

    International Nuclear Information System (INIS)

    Quispe H, B.; Pena V, J. D.; Waldo B, G.; Leon M, M.; Ceron R, P.; Vallejo H, A.; Sosa A, M.; Vega C, H. R.

    2017-10-01

    Computed tomography is a diagnostic imaging method that deposits higher doses than other radio diagnosis methods. The knowledge of the spectrum of X-rays is important, since is in direct function with the dose absorbed by the patient. In this work we estimated the spectrum of X-rays, produced during the interaction of monoenergetic electrons of 130 KeV with Tungsten white, in order to determine their energetic characteristics at 50 cm from the focal point. The study was done using Monte Carlo methods with the code MCNP5 where the X-ray tube of a Siemens SOMATOM Perspective tomograph of the General Regional Hospital of Leon, Mexico was modeled. In the calculations, 3 x 10 8 stories were used and a relative uncertainty of less than 0.1% was obtained. Also, a neck manikin with thyroid, thorax and head that included the eye, the table and gantry with 70 cm opening of the tomography was modeled. The X-ray spectrum calculated with a cut thickness of 10 mm limited by Pb collimators was used as the source term. The radiological service routine scanning protocol was used for chest computed tomography; the step-by-step or instant trigger method was simulated by moving the manikin coordinates for each cut and 360 degree continuous rotation movement. 36 positions of the X-ray tube were used in steps of 10 degrees. The radiation dispersed in the thorax deposits a dose of 2.063 mGy in crystalline and 252 mGy in thyroid. (Author)

  15. Determining lethal dose of gamma radiation on different stages of Tribolium Cosmonauts H b s t

    International Nuclear Information System (INIS)

    Zolfagharieh, H.R.; Majd, F.; Torshyzie, M.; Babaie, M.

    1992-10-01

    Pest infestation causes great losses to stored grain through out the world. This is specially true in developing countries where the technology is less advanced, and climatic conditions are extremely favourable for the development of pests. Irradiation is on approved method of direct control for stored-product insect in wheat and wheat flour in many countries, and in dictation are that it will soon be approved for all grain, grain products and other dry food commodities. Radiation doses required to kill or sterilized the most important storage pests in all stages are known. However irradiation is very effective in preventing insect development and in producing sterility. A detailed analysis of the radiosensitivity of stored-product insects shows the different groups of pests have very different sensitivities and quarantine doses can be tailored to kill or sterilize the species of quarantine concern. The effect of irradiation on insects are many, and varied, depending primarily on the species, stage, age and physical factors. The aim is to survey the effect of gamma radiation on stored pest, which can categorized under following classes: 1-The effect of gamma radiation on different stages grow of tribolium castaneum (H B S T); 2-Determination of lethal doses.; 3-The study of gamma radiation on products. In summary these information indicated that fairly low dosages of gamma radiation could be used on commodities such as bulk grain in which some infestation by insect stages of irradiation would be required on products such package foods where hundred percent mortality must be obtain. (author)

  16. Hypofractionated stereotactic radiotherapy to the rat hippocampus. Determination of dose response and tolerance

    International Nuclear Information System (INIS)

    Ernst-Stecken, A.; Roedel, F.; Grabenbauer, G.; Sauer, R.; Jeske, I.; Bluemcke, I.; Hess, A.; Ganslandt, O.; Brune, K.

    2007-01-01

    Purpose: To determine the effect of hypofractionated stereotactic radiotherapy (hfSRT) on adult rat brain tissue (necrosis, impact on blood-brain barrier, signal changes on high-field magnetic resonance imaging [MRI]). Material and Methods: Adult male Wistar rats underwent MRI and CT scanning of the brain and respective images were introduced into the Novalis trademark radiosurgery device (BrainLab, Feldkirchen, Germany). All animals (body weight 350 g) were irradiated weekly with doses of 2 x 10 Gy (n = 3 animals), 3 x 10 Gy (n = 3 animals) and 4 x 10 Gy (n = 3 animals), targeted to the left hippocampus after image-guided positioning. 4.7-T T2-weighted MRI scanning was performed in each animal. Animals were sacrificed 8, 12, and 16 weeks after hfSRT and brains were immersion-fixed in 4% paraformaldehyde for subsequent histopathologic analysis. Results: In concordance with isodose distributions, pathologic signal hyperintensities in MRI were recorded from 4 x 10 Gy after 8 weeks, 3 x 10 Gy after 12 weeks, while 2 x 10 Gy induced slight detectable alterations only after 16 weeks. Subsequent histopathologic analysis revealed hippocampal cell necrosis with significantly earlier and stronger occurrence for higher doses (40 Gy > 30 Gy > 20 Gy). Pial microvessel permeability also increased after 40 Gy, whereas 30 Gy induced moderate changes. Conclusion: Conclusion: Partial-brain irradiation with hfSRT (Novalis trademark System) was successfully adopted for small animals and histopathologic analysis confirmed its repositioning accuracy. The neuropathologic effects correlated with dose and observation time. The approach will be further developed for quality assurance in hfSRT of normal brain tissue, as well as novel treatment modalities in epileptic rats and orthotopic tumor models. (orig.)

  17. Committed effective dose determination in cereal flours by gamma-ray spectrometry; Determinacao das doses efetivas por ingestao de farinhas de cereais atraves da espectrometria de raios gama

    Energy Technology Data Exchange (ETDEWEB)

    Scheibel, Viviane

    2006-07-01

    The health impact from radionuclides ingestion of foodstuffs was evaluated by the committed effective doses determined in commercial samples of South-Brazilian cereal flours (soy, wheat, corn, manioc, rye, oat, barley and rice flour). The radioactivity traces of {sup 228}Th, {sup 228}Ra, {sup 226}Ra, {sup 40}K, {sup 7}Be and {sup 137}Cs were measured by gamma-ray spectrometry employing a 66% relative efficiency HPGe detector. The energy resolution for the 1332.46 keV line of {sup 60}Co was 2.03 keV. The committed effective doses were calculated with the activities analyzed in the present flour samples, the foodstuff rates of consumption (Brazilian Institute of Geography and Statistics) and the ingestion dose coefficients (International Commission of Radiological Protection). The reliability median activities were verified with {chi}{sup 2} tests, assuring the fittings quality. The highest concentration levels of {sup 228}Th and {sup 40}K were 3.5 {+-} 0.4 and 1469 {+-} 17 Bq.kg{sup -1} for soy flour, respectively, with 95% of confidence level. The lower limit of detection for {sup 137}Cs ranged from 0.04 to 0.4 Bq.kg{sup -1}. The highest committed effective dose was 0.36 {mu}Sv.y{sup -1} for {sup 228}Ra in manioc flour (adults). All committed effective doses determined at the present work were lower than the UNSCEAR limits of 140 {mu}Sv.y{sup -1} and much lower than the ICRP (1991) limits of 1 mSv.y{sup -1}, for general public. There are few literature references for natural and artificial radionuclides in foodstuffs and mainly for committed effective doses. This work brings the barley flour data, which is not present at the literature and {sup 7}Be data which is not encountered in foodstuffs at the literature, besides all the other flours data information about activities and committed effective doses. (author)

  18. Nondestructive neutron activation analysis of silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Vandergraaf, T. T.; Wikjord, A. G.

    1973-10-15

    Instrumentel neutron activation analysis was used to determine trace constituents in silicon carbide. Four commercial powders of different origin, an NBS reference material, and a single crystal were characterized. A total of 36 activation species were identified nondestructively by high resolution gamma spectrometry; quantitative results are given for 12 of the more predominant elements. The limitations of the method for certain elements are discussed. Consideration is given to the depression of the neutron flux by impurities with large neutron absorption cross sections. Radiation fields from the various specimens were estimated assuming all radionuclides have reached their saturation activities. (auth)

  19. Nondestructive analysis of plutonium contaminated soil

    International Nuclear Information System (INIS)

    Smith, H.E.; Taylor, L.H.

    1977-01-01

    Plutonium contaminated soil is currently being removed from a covered liquid waste disposal trench near the Pu Processing facility on the Hanford Project. This soil with the plutonium is being mined using remote techniques and equipment. The mined soil is being packaged for placement into retrievable storage, pending possible recovery. To meet the requirements of criticality safety and materials accountability, a nondestructive analysis program has been developed to determine the quantity of plutonium in each packing-storage container. This paper describes the total measurement program: equipment systems, calibration techniques, matrix assumption, instrument control program and a review of laboratory operating experience

  20. A 'hybrid' neutron area survey instrument for the determination of neutron dose quantities in the workplace

    International Nuclear Information System (INIS)

    Tanner, R.J.; Jenkins, R.; Lowe, T.; Silvie, J.; Joyce, M.J.; Winsby, A.; Molinos, C.

    2005-01-01

    Full text: Neutron survey instruments are used routinely to determine the dose rates in areas where persons may be occupationally exposed. With a few exceptions, these instruments generally use a proportional counter with a high thermal neutron response located in a moderating sphere of CH 2 . The moderating sphere in such designs contains a thermal neutron absorber to reduce the over-response to thermal and intermediate energy neutrons. However, the commercially available examples of such instruments tend to have strongly energy dependent ambient dose equivalent response characteristics. In particular, they often over-respond in the energy range between 1 eV and 10 keV. A prototype of a novel design has been produced that uses seven detectors located in a moderating sphere of CH 2 , six near the surface to detect thermal and epithermal neutrons, and one in the centre to detect fast neutrons. This has been characterized using a combination of MCNP modelling and measurements to produce an instrument that has improved energy dependence of response characteristics. Additionally, the use of seven detectors offers direction and field hardness information. The design and calibration of the instrument are described and its response in workplaces calculated. (author)

  1. Determination of optimal doses of radiation for the plant breeding of pseudo cereals

    International Nuclear Information System (INIS)

    Gonzalez J, J.; Gomez P, L.

    2005-01-01

    With the purpose of promoting the use of the radiations for the plant breeding of pseudo cereals, it was determined a simple and economic method that allows the quick selection of radiation dose that induce in the vegetable organisms the changes wanted. For it it was work with quinua seeds (Chenopodium quinoa Willd.) an Andean pseudo cereal that, due to their nutritious and physiologic characteristics it is considered by the FAO like one of the foods of the future and for the NASA like an organism that is good to remove the carbon dioxide from the atmosphere and at the same time, to generate food, oxygen and water for the crew during the space missions of long duration and that it has already improved by means of the radiation application. The proposed method consists on the evaluation, of the embryonic structures (radicule, hypocotyl and cotyledons) in the irradiated seeds as well as of the development of root, primary shaft and true leaves in the plants. The changes in the growth, form, number and color of the structures as well as the time of appearance of each one, allow to predict the morphological changes and inclusive some physiologic ones that will have the mature organisms, so that in only three weeks it is possible to select the doses more appropriate. (Author)

  2. Determination of dose components in mixed gamma neutron fields by use of high pressure ionization chambers

    International Nuclear Information System (INIS)

    Golnik, N.; Pliszczynski, T.; Wysocka, A.; Zielczynski, M.

    1985-01-01

    The two ionization chamber method for determination of dose components in mixed γ-neutron field has been improved by increasing gas pressure in the chambers up to some milions pascals. Advantages of high pressure gas filling are the followings: 1) significant reduction of the ratio of neutron-to gamma sensitivity for the hydrogen-free chamber, 2) possibility of sensitivity correction for both chambers by application of appropriate voltage, 3) high sensitivity for small detectors. High-pressure, pen-like ionization chambers have been examined in fields of different neutron sources: a TE-chamber, filled with 0.2 MPa of quasi-TE-gas and a conductive PTFE chamber, filled with 3.1 MPa of CO 2 . The ratio of neutron-to-gamma sensitivity for the PTFE chamber, operated at electrical field strength below 100 V/cm, has not exceeded 0.01 for neutrons with energy below 8 MeV. Formula is presented for calculation of this ratio for any high-pressure, CO 2 -filled ionization chamber. Contribution of gamma component to total tissue dose in the field of typical neutron sources has been found to be 3 to 70%

  3. A method, using ICRP 26 weighting factors, to determine effective dose equivalent due to nonuniform external exposures

    International Nuclear Information System (INIS)

    Dyer, S.G.

    1993-01-01

    Westinghouse Savannah River Company (WSRC) has recently implemented a methodology and supporting procedures to calculate effective dose equivalent for external exposures. The calculations are based on ICRP 26 methodology and are used to evaluate exposures when multibadging is used. The methodology is based upon the concept of open-quotes whole bodyclose quotes compartmentalization (i.e., the whole body is separated into seven specific regions of radiological concern and weighted accordingly). The highest dose measured in each compartment is used to determine the weighted dose to that compartment. Benefits of determining effective dose equivalent are compliance with DOE Orders, more accurate dose assessments, and the opportunity for improved worker protection through new ALARA opportunities

  4. Evaluation of the Accuracy of Polymer Gels for Determining Electron Dose Distributions in the Presence of Small Heterogeneities.

    Science.gov (United States)

    Asl, R Ghahraman; Nedaie, H A; Banaee, N

    2017-12-01

    The aim of this study is to evaluate the application and accuracy of polymer gels for determining electron dose distributions in the presence of small heterogeneities made of bone and air. Different cylindrical phantoms containing MAGIC (Methacrylic and Ascorbic acid in Gelatin Initiated by Copper) normoxic polymer gel were used under the slab phantoms during irradiation. MR images of the irradiated gel phantoms were obtained to determine their R2 (spin-spin) relaxation maps for conversion to absorbed dose. One- and 2-dimensional lateral dose profiles were acquired at depths of 1 and 4 cm for 8 and 15 MeV electron beams. The results were compared with the doses measured by a diode detector at the same positions. In addition, the dose distribution in the axial orientation was measured by the gel dosimeter. The slope and intercept for the R2 versus dose curve were 0.509 ± 0.002 Gy s and 4.581 ± 0.005 s, respectively. No significant variation in dose-R2 response was seen for the two electron energies within the applied dose ranges. The mean dose difference between the measured gel dose profiles was smaller than 3% compared to those measured by the diode detector. These results provide further demonstration that electron dose distributions are significantly altered in the presence of tissue inhomogeneities such as bone and air cavity and that MAGIC gel is a useful tool for 3-dimensional dose visualization and qualitative assessment of tissue inhomogeneity effects in electron beam dosimetry.

  5. Preparation and determination of kerma for Iridium 192 sources of low dose rate for brachytherapy

    International Nuclear Information System (INIS)

    Tendilla, J.I.; Tovar M, V.; Mitsoura, E.; Aguilar H, F.; Alanis M, J.

    2000-01-01

    The practice of Brachytherapy with Iridium-192 sources of low dose rate (0.4 - 0.8 Gy/h) is a technique used in the treatment of diverse illnesses. in this work the preparation, quality control and calibration are presented in terms of kerma in air of Iridium-192 using as target these recycled Iridium-Platinum wires. The targets were obtained as decayed sources of different radio therapeutical centers in the country and they were characterized by Scanning electron microscopy in order to determine their chemical composition. Subsequently it was developed an experimental design to establish the effect of neutron flux, geometrical array and irradiation time over the activity and percentage of the sources homogeneity. The homogeneity was determined by auto radiography and by Gamma spectroscopy. Once the optimal irradiation conditions were established, it is determined the apparent activity and kerma in air using a well type ionization chamber with traceability to a primary laboratory. Iridium-192 sources were obtained with an average homogeneity 96 %, apparent activity 282.129 ± 0.531 M Bq and kerma in air 0.03200 ± 0.00006 m Gy m/h A. (Author)

  6. 49 CFR 192.243 - Nondestructive testing.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Nondestructive testing. 192.243 Section 192.243... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192.243 Nondestructive testing. (a) Nondestructive testing of welds must be performed by any process, other than trepanning, that...

  7. Pharmacokinetic/pharmacodynamic modeling for the determination of a cimicoxib dosing regimen in the dog.

    Science.gov (United States)

    Jeunesse, Elisabeth C; Schneider, Marc; Woehrle, Frederique; Faucher, Mathieu; Lefebvre, Herve P; Toutain, Pierre-Louis

    2013-12-11

    Cimicoxib is a new coxib anti-inflammatory drug for use in the dog. To determine a preclinical dosage regimen for cimicoxib in dog, a reversible model of kaolin-induced paw inflammation was used. Dosage regimens were established using pharmacokinetic/pharmacodynamic (PK/PD) modeling approach (indirect response model). Analgesic, anti-inflammatory and antipyretic endpoints investigated with the inflammation model established the efficacy of cimicoxib at a dose of 2 mg/kg administered orally (single dose) in 12 beagle dogs.For both the oral and IV route of administration two groups of dogs to be identified namely Poor Metabolizers (PM) and Extensive Metabolizers (EM).The terminal half-life after oral administration was 8.0 ± 0.6 h for the PM and 4.6 ± 2.6 h for the EM groups, with the corresponding values after the IV route being 5.6 ± 1.7 h and 2.7 ± 0.9 h (mean ± SD).The main pharmacodynamic parameters (potency, efficacy, and sensitivity) were estimated for four endpoints (body temperature, creeping speed, ground vertical reaction force and clinical lameness score). The plasma concentration corresponding to half the maximum of the indirect effect were 239 μg/L for creeping speed, 284 μg/L for the lameness score, 161 μg/L for the ground reaction vertical force and 193 μg/L for the body temperature.To document possible polymorphism of the cimicoxib disposition in the target dog population, cimicoxib was administered by the intravenous route to 40 dogs (four different sized breeds). The cimicoxib half-lives in these 40 dogs were of same order of the magnitude as those of the EM beagle dogs. Thus pharmacokinetic and pharmacodynamic parameters obtained from the EM beagle dogs were selected to simulate the dose-effect relationship of cimicoxib after an oral administration allowing a dosage regimen to be selected for confirmation by a clinical trial. Cimicoxib was an efficacious anti-inflammatory, antipyretic and analgesic drug and a dosage regimen of 2 mg

  8. Recent improvements concerning nondestructive testing

    International Nuclear Information System (INIS)

    Asty, M.

    1984-12-01

    Rare are the techniques of which development is not already touched by microelectronics and micro-data processing. Nondestructive testing and more particularly ultrasonic and Foucault current testing follow this general rule. With some examples, this paper focuses on the potential of numerical signal processing [fr

  9. Nondestructive testing at the CEA

    International Nuclear Information System (INIS)

    Colomer, J.; Lucas, G.

    1976-01-01

    The different nondestructive testing methods used at the CEA are presented: X-ray or gamma radiography, X-ray stress analysis, neutron radiography, ultrasonic testing, eddy currents, electrical testing, microwaves, thermal testing, acoustic emission, optical holography, tracer techniques. (102 references are cited) [fr

  10. [Determination of the integral dose in computer tomography of the neurocranium].

    Science.gov (United States)

    Rahim, H; Hofmann, W; Grobovschek, M; Mandl, H

    1985-12-01

    The amount of exposure of the cranium is calculated on the basis of the measured dose distribution in craniocaudal direction and on the axial planes of the Alderson phantom. The integral dose of the cranium and the local dose at sensitive organs are used as a measure of radiation exposure.

  11. Real time determination of dose radiation through artificial intelligence and virtual reality; Determinacao de dose de radiacao, em tempo real, atraves de inteligencia artificial e realidade virtual

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Victor Goncalves Gloria

    2009-07-01

    In the last years, a virtual environment of Argonauta research reactor, sited in the Instituto de Engenharia Nuclear (Brazil), has been developed. Such environment, called here Argonauta Virtual (AV), is a 3D model of the reactor hall, in which virtual people (avatar) can navigate. In AV, simulations of nuclear sources and doses are possible. In a recent work, a real time monitoring system (RTMS) was developed to provide (by means of Ethernet TCP/I P) the information of area detectors situated in the reactor hall. Extending the scope of AV, this work is intended to provide a continuous determination of gamma radiation dose in the reactor hall, based in several monitored parameters. To accomplish that a module based in artificial neural network (ANN) was developed. The ANN module is able to predict gamma radiation doses using as inputs: the avatar position (from virtual environment), the reactor power (from RTMS) and information of fixed area detectors (from RTMS). The ANN training data has been obtained by measurements of gamma radiation doses in a mesh of points, with previously defined positions, for different power levels. Through the use of ANN it is possible to estimate, in real time, the dose received by a person at any position in Argonauta reactor hall. Such approach allows tasks simulations and training of people inside the AV system, without exposing them to radiation effects. (author)

  12. Validation of a MOSFET dosemeter system for determining the absorbed and effective radiation doses in diagnostic radiology.

    Science.gov (United States)

    Manninen, A-L; Kotiaho, A; Nikkinen, J; Nieminen, M T

    2015-04-01

    This study aimed to validate a MOSFET dosemeter system for determining absorbed and effective doses (EDs) in the dose and energy range used in diagnostic radiology. Energy dependence, dose linearity and repeatability of the dosemeter were examined. The absorbed doses (ADs) were compared at anterior-posterior projection and the EDs were determined at posterior-anterior, anterior-posterior and lateral projections of thoracic imaging using an anthropomorphic phantom. The radiation exposures were made using digital radiography systems. This study revealed that the MOSFET system with high sensitivity bias supply set-up is sufficiently accurate for AD and ED determination. The dosemeter is recommended to be calibrated for energies 80 kVp. The entrance skin dose level should be at least 5 mGy to minimise the deviation of the individual dosemeter dose. For ED determination, dosemeters should be implanted perpendicular to the surface of the phantom to prevent the angular dependence error. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Determination of electron depth-dose curves for water, ICRU tissue, and PMMA and their application to radiation protection dosimetry

    International Nuclear Information System (INIS)

    Grosswendt, B.

    1994-01-01

    For monoenergetic electrons in the energy range between 60 keV and 10 MeV, normally incident on water, 4-element ICRU tissue and PMMA phantoms, depth-dose curves have been calculated using the Monte Carlo method. The phantoms' shape was that of a rectangular solid with a square front face of 30 cm x 30 cm and a thickness of 15 cm; it corresponds to that recommended by the ICRU for use in the procedure of calibrating radiation protection dosemeters. The depth-dose curves have been used to determine practical ranges, half-value depths, electron fluence to maximum absorbed dose conversion factors, and conversion factors between electron fluence and absorbed dose at depths d corresponding to 0.007 g.cm -2 , 0.3 g.cm -2 , and 1.0 g.cm -2 . The latter data can be used as fluence to dose equivalent conversion factors for extended parallel electron beams. (Author)

  14. Pattern recognition approach to nondestructive evaluation of materials

    International Nuclear Information System (INIS)

    Chen, C.H.

    1987-01-01

    In this paper, a pattern recognition approach to the ultrasonic nondestructive evaluation of materials is examined. Emphasis is placed on identifying effective features from time and frequency domains, correlation functions and impulse responses to classify aluminum plate specimens into three major defect geometry categories: flat, angular cut and circular hole defects. A multi-stage classification procedure is developed which can further determine the angles and sizes for defect characterization and classification. The research clearly demonstrates that the pattern recognition approach can significantly improve the nondestructive material evaluation capability of the ultrasonic methods without resorting to the solution of highly complex mathematical inverse problems

  15. Development of hotcell non-destructive examination techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Uhn; Yu, S. C.; Kang, B. S.; Byun, K. S. [Chungbuk National University, Chungju (Korea)

    2002-01-01

    The purpose of this project is to establish non-destructive examination techniques which needs to determine the status of spent nuclear fuel and/or bundles. Through the project, we will establish an image reconstruction tomography which is a kind of non-destructive techniques in Hotcell. The tomography technique can be used to identify the 2-dimensional density distribution of fission products in the spent fuel rods and/or bundles. And form results of the measurement and analysis of magnetic properties of neutron irradiated material in the press vessel and reactor, we will develop some techniques to test its hardness and defects. In 2001, the first year, we have established mathematical background and necessary data and informations to develop the techniques. We will try to find some experimental results that are necessary in developing the Hotcell non-destructive examination techniques in the coming year. 14 refs., 65 figs., 5 tabs. (Author)

  16. Experimental ratio between the 'real' dose per organ and the calculated dose determined by means of the Embalse nuclear power plant's personal dosimeter

    International Nuclear Information System (INIS)

    Thomasz, E.; Salas, C.A.

    1987-01-01

    The specific purpose of the study was to determine the experimental ratio between the reading of dosimeters used by the personnel of the Embalse nuclear power plant and the 'real' dose absorbed by the worker in different organs. An anthropomorphic phantom ALDERSON internal and externally loaded with approximately 150 TLD crystals was used. This phantom was placed in five enclosures that were usually occupied by workers of the Embalse nuclear power plant. In this way, the average dose per organ and the effective equivalent dosis in each enclosure could be calculated and compared with the personal dosimeters placed over the thorax and the conversion factor rem/rem for each enclosure was determined. The average factor resulting from the five considered enclosures was 0.73 rem/rem. This means that the personal dosimeters over value the real dosis absorbed by the personnel of the Embalse nuclear power plant in approximately 37%. (Author)

  17. Radiation control in the nondestructive inspection

    International Nuclear Information System (INIS)

    Kariya, Yukihiro

    1982-01-01

    In the early days of radiation nondestructive inspection about ten years ago, the loss of radiation sources and careless radiation exposure gave the impression of radiography inspection being immediately slipshod management. In this problem, the peculiar nature of the business in this field is involved. In Nondestructive Inspection Co., Ltd., besides the safety management of radioisotopes, the radiation exposure control of personnel in the regular inspection of nuclear power plants has become increasingly important. The following matters are described: radiation utilization in nondestructive inspection (X- and #betta#-ray radiography, #betta#-ray leak test on shield), radiation control problems in nondestructive inspection business (the peculiar aspects of the business, the analysis of the incidents related with nondestructive inspection), and the practice of radiation control in nondestructive inspection in Nondestructive Inspection Co., Ltd. (Mori, K.)

  18. Tacrolimus dose requirements in paediatric renal allograft recipients are characterized by a biphasic course determined by age and bone maturation

    NARCIS (Netherlands)

    Knops, N.; Herman, J.; Dyck, M. van; Ramazani, Y.; Debbaut, E.; Damme-Lombaerts, R. van; Levtchenko, E.N.; Heuvel, L.P.W.J. van den; Fieuws, S.; Kuypers, D.

    2017-01-01

    AIMS: Despite longstanding recognition of significant age-dependent differences in drug disposition during childhood, the exact course and the underlying mechanisms are not known. Our aim was to determine the course and determinants of individual relative dose requirements, during long-term

  19. Determination of the maximum individual dose exposure resulting from a hypothetical LEU plate-melt accident

    International Nuclear Information System (INIS)

    Abdelhady, Amr

    2013-01-01

    Highlights: ► Studying the radioactive release results from hypothetical plate-melt accident. ► Hotspot code was used to study the dose distributions around the reactor. ► A 90% decrease in the received dose in proper operation of filtration. ► The received dose is lower than the annual permissible dose after filtration. - Abstract: The objective of this study was to provide an estimate of the potential impact of accidental radioactive release from the testing cell of the Egyptian second research reactor ETRR-2 on the dose level of public around the reactor. The assessment was performed for two cases: an evaluation of the impact that accidental release has on the dose that would be received by public around the reactor in case of proper operation of testing cell filtration system; and an assessment of the potential dose in case of loss of testing cell filtration system. The results show that the filtration system has a great role in decreasing the dose received by an individual located outside the reactor to a dose level lower than the annual permissible dose

  20. SU-G-206-05: A Comparison of Head Phantoms Used for Dose Determination in Imaging Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Z; Vijayan, S; Kilian-Meneghin, J; Rudin, S; Bednarek, D [Toshiba Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY (United States)

    2016-06-15

    Purpose: To determine similarities and differences between various head phantoms that might be used for dose measurements in diagnostic imaging procedures. Methods: We chose four frequently used anthropomorphic head phantoms (SK-150, PBU-50, RS-240T and Alderson Rando), a computational patient phantom (Zubal) and the CTDI head phantom for comparison in our study. We did a CT scan of the head phantoms using the same protocol and compared their dimensions and CT numbers. The scan data was used to calculate dose values for each of the phantoms using EGSnrc Monte Carlo software. An .egsphant file was constructed to describe these phantoms using a Visual C++ program for DOSXYZnrc/EGSnrc simulation. The lens dose was calculated for a simulated CBCT scan using DOSXYZnrc/EGSnrc and the calculated doses were validated with measurements using Gafchromic film and an ionization chamber. Similar calculations and measurements were made for PA radiography to investigate the attenuation and backscatter differences between these phantoms. We used the Zubal phantom as the standard for comparison since it was developed based on a CT scan of a patient. Results: The lens dose for the Alderson Rando phantom is around 9% different than the Zubal phantom, while the lens dose for the PBU-50 phantom was about 50% higher, possibly because its skull thickness and the density of bone and soft tissue are lower than anthropometric values. The lens dose for the CTDI phantom is about 500% higher because of its totally different structure. The entrance dose profiles are similar for the five anthropomorphic phantoms, while that for the CTDI phantom was distinctly different. Conclusion: The CTDI and PBU-50 head phantoms have substantially larger lens dose estimates in CBCT. The other four head phantoms have similar entrance dose with backscatter hence should be preferred for dose measurement in imaging procedures of the head. Partial support from NIH Grant R01-EB002873 and Toshiba Medical Systems

  1. Photon spectrometry for the determination of the dose-rate constant of low-energy photon-emitting brachytherapy sources

    International Nuclear Information System (INIS)

    Chen, Zhe Jay; Nath, Ravinder

    2007-01-01

    Accurate determination of dose-rate constant (Λ) for interstitial brachytherapy sources emitting low-energy photons (<50 keV) has remained a challenge in radiation dosimetry because of the lack of a suitable absolute dosimeter for accurate measurement of the dose rates near these sources. Indeed, a consensus value of Λ taken as the arithmetic mean of the dose-rate constants determined by different research groups and dosimetry techniques has to be used at present for each source model in order to minimize the uncertainties associated with individual determinations of Λ. Because the dosimetric properties of a source are fundamentally determined by the characteristics of the photons emitted by the source, a new technique based on photon spectrometry was developed in this work for the determination of dose-rate constant. The photon spectrometry technique utilized a high-resolution gamma-ray spectrometer to measure source-specific photon characteristics emitted by the low-energy sources and determine their dose-rate constants based on the measured photon-energy spectra and known dose-deposition properties of mono-energetic photons in water. This technique eliminates many of the difficulties arising from detector size, the energy dependence of detector sensitivity, and the use of non-water-equivalent solid phantoms in absolute dose rate measurements. It also circumvents the uncertainties that might be associated with the source modeling in Monte Carlo simulation techniques. It was shown that the estimated overall uncertainty of the photon spectrometry technique was less than 4%, which is significantly smaller than the reported 8-10% uncertainty associated with the current thermo-luminescent dosimetry technique. In addition, the photon spectrometry technique was found to be stable and quick in Λ determination after initial setup and calibration. A dose-rate constant can be determined in less than two hours for each source. These features make it ideal to determine

  2. Determination of intake and internal radiation dose for occupationally exposed workers to iodine 131

    International Nuclear Information System (INIS)

    Kharita, M. H.; Maghrabi, M.; Sadyya, A.

    2004-12-01

    Workers who prepare and inject radioactive Iodine I 131 doses at the medical centers in Syria are potentially exposed to the radioactive intake by ingestion or inhalation during preparation or injection processes. The received amount of the radioactive intake differs according to the amount of the I 131 that released during the preparation or injection processes, and to the work conditions and the applying ways of the radiation protection principles. Because of this radioactive intake, the thyroid gland may expose to amounts of I 131 which may negatively affect the health of the workers, so it is necessary to make routine monitoring for all workers who receive an intake of more than 10% of the annual intake limit which is (2*10 6 Bq/y) for I 131 . To make this monitoring process, it is necessary to use either the thyroid gland counter in order to know the concentrated amount of the radioactivity in the gland, or the analysis of a 24 hours urine sample of the exposed workers to determine the eliminated amount of the radioactivity using gamma spectrometry, also the two processes can be applied at the same time. Since the thyroid gland counter is not available, the analysis of urine sample was done to determine the concentrated amount of the radioactivity in urine, then to estimate the radioactive intake and the internal radioactive dose. The results of applying this method dictated that some workers work in safe conditions according to the radiation protection and there is no need for them to make routine monitoring . But the other workers receive a radioactive intake of about 10% yearly of the annual intake limit and that requires a routine periodical monitoring for those workers in addition to the necessity of applying the principles of the radiation protection during the work with I 131 . These principles and systems should indicate the basic requirement of radiation protection that must be available in the laboratory that deal with I 131 either for therapy or for

  3. WE-E-18A-03: How Accurately Can the Peak Skin Dose in Fluoroscopy Be Determined Using Indirect Dose Metrics?

    International Nuclear Information System (INIS)

    Jones, A; Pasciak, A

    2014-01-01

    Purpose: Skin dosimetry is important for fluoroscopically-guided interventions, as peak skin doses (PSD) that Result in skin reactions can be reached during these procedures. The purpose of this study was to assess the accuracy of different indirect dose estimates and to determine if PSD can be calculated within ±50% for embolization procedures. Methods: PSD were measured directly using radiochromic film for 41 consecutive embolization procedures. Indirect dose metrics from procedures were collected, including reference air kerma (RAK). Four different estimates of PSD were calculated and compared along with RAK to the measured PSD. The indirect estimates included a standard method, use of detailed information from the RDSR, and two simplified calculation methods. Indirect dosimetry was compared with direct measurements, including an analysis of uncertainty associated with film dosimetry. Factors affecting the accuracy of the indirect estimates were examined. Results: PSD calculated with the standard calculation method were within ±50% for all 41 procedures. This was also true for a simplified method using a single source-to-patient distance (SPD) for all calculations. RAK was within ±50% for all but one procedure. Cases for which RAK or calculated PSD exhibited large differences from the measured PSD were analyzed, and two causative factors were identified: ‘extreme’ SPD and large contributions to RAK from rotational angiography or runs acquired at large gantry angles. When calculated uncertainty limits [−12.8%, 10%] were applied to directly measured PSD, most indirect PSD estimates remained within ±50% of the measured PSD. Conclusions: Using indirect dose metrics, PSD can be determined within ±50% for embolization procedures, and usually to within ±35%. RAK can be used without modification to set notification limits and substantial radiation dose levels. These results can be extended to similar procedures, including vascular and interventional oncology

  4. An algorithm to include the bremsstrahlung component in the determination of the absorbed dose in electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Klevenhagen, S C [The Royal London Hospital, London (United Kingdom). Medical Physics Dept.

    1996-08-01

    Currently used dosimetry protocols for absolute dose determination of electron beams from accelerators in radiation therapy do not account for the effect of the bremsstrahlung contamination of the beam. This results in slightly erroneous doses calculated from ionization chamber measurements. In this report the deviation is calculated and an improved algorithm, which accounts for the effect of the bremsstrahlung component of the beam, is suggested. (author). 14 refs, 2 figs, 1 tab.

  5. The Evaluation of personnel radiation dose and society radiation on RSG-GAS around as proposal determination of ALARA value

    International Nuclear Information System (INIS)

    Pande Made Udiyani; Puradwi IW

    2007-01-01

    Each nuclear installation to achieve radiation safety has to meet the ALARA concepts. The ALARA value of a nuclear installation should be enacted by regulator body. ALARA value can be determined by evaluation radiation exposure and dose acceptance of nuclear installation operation. As case study in Indonesia, ALARA assessment in nuclear installation is done at RSG-GAS reactor. Intention of this research is to determine gyration reference assess ALARA by evaluate radiation dose acceptance by RSG-GAS radiation personnel and the influence of RSG-GAS operation to presentation of radiation accepted by society which living around its. ALARA of RSG-GAS determined based on evaluation of measurement data of the radiation doses which is accepted by personnel radiation. While evaluation of radiation doses which is accepted by society in the radius 5 km of the RSG-GAS conducted to data result of calculation using program package of CAP-88 and measurement result with method of carborne survey. Result of radiation dose evaluation obtained which not pass dose definition for the radiation worker that is 50 mSv/year, and for society around RSG-GAS that is 5 mSv/year. Based on the result of evaluation hence obtained value of ALARA for RSG-GAS in value of gyration 17 - 50 mSv/year. (author)

  6. Absorbed dose determination in external beam radiotherapy. An international code of practice for dosimetry based on standards of absorbed dose to water

    International Nuclear Information System (INIS)

    2000-01-01

    The International Atomic Energy Agency published in 1987 an International Code of Practice entitled 'Absorbed Dose Determination in Photon and Electron Beams' (IAEA Technical Reports Series No. 277 (TRS-277)), recommending procedures to obtain the absorbed dose in water from measurements made with an ionization chamber in external beam radiotherapy. A second edition of TRS-277 was published in 1997 updating the dosimetry of photon beams, mainly kilovoltage X rays. Another International Code of Practice for radiotherapy dosimetry entitled 'The Use of Plane-Parallel Ionization Chambers in High Energy Electron and Photon Beams' (IAEA Technical Reports Series No. 381 (TRS-381)) was published in 1997 to further update TRS-277 and complement it with respect to the area of parallel-plate ionization chambers. Both codes have proven extremely valuable for users involved in the dosimetry of the radiation beams used in radiotherapy. In TRS-277 the calibration of the ionization chambers was based on primary standards of air kerma; this procedure was also used in TRS-381, but the new trend of calibrating ionization chambers directly in a water phantom in terms of absorbed dose to water was introduced. The development of primary standards of absorbed dose to water for high energy photon and electron beams, and improvements in radiation dosimetry concepts, offer the possibility of reducing the uncertainty in the dosimetry of radiotherapy beams. The dosimetry of kilovoltage X rays, as well as that of proton and heavy ion beams, interest in which has grown considerably in recent years, can also be based on these standards. Thus a coherent dosimetry system based on standards of absorbed dose to water is possible for practically all radiotherapy beams. Many Primary Standard Dosimetry Laboratories (PSDLs) already provide calibrations in terms of absorbed dose to water at the radiation quality of 60 Co gamma rays. Some laboratories have extended calibrations to high energy photon and

  7. Determination of effective dose in pediatric radiodiagnostic in Medellin-Colombia

    International Nuclear Information System (INIS)

    Garzon, William J.; Aramburo, Javier M.; Jimenez, Angelmiro A.; Ortiz, Anselmo P.

    2013-01-01

    In order to know the effective dose in pediatric X-ray exams of chest, entrance surface dose measurements were performed for ages 1,5 and 10 years in the largest pediatric hospital in the city of Medellin, Colombia. The effective dose was obtained from applying the conversion coefficients to measures of the entrance surface dose (ESD) in 306 radiographic studies in AP and LAT I projections. The results were validated with PCXMC 2.0 computer program and other work reported in the literature. (author)

  8. Nondestructive testing of concrete structures

    International Nuclear Information System (INIS)

    Rufino, Randy R.; Relunia, Estrella

    1999-01-01

    Nondestructive testing of concrete is highly inhomogeneous which makes it cumbersome to setup experimental procedures and analyze experimental data. However, recent research and development activities have discovered the different methods of NDT, like the electromagnetic method, ultrasonic pulse velocity test, pulse echo/impact echo test, infrared thermography, radar or short pulse radar techniques, neutron and gamma radiometry, radiography, carbonation test and half-cell potential method available for NDT of concrete structures. NDT of concrete is emerging as a useful tool for quality control and assurance. This papers also describes the more common NDT methods discussed during the two-week course on 'Nondestructive Testing of Concrete Structures', held at the Malaysian Institute for Nuclear Technology Research (MINT) in Malaysia, which was jointly organized by MINT and the International Atomic Energy Agency (IAEA)

  9. Nondestructive assay of sale materials

    International Nuclear Information System (INIS)

    Rodenburg, W.W.; Fleissner, J.G.

    1981-01-01

    This paper covers three primary areas: (1) reasons for performing nondestructive assay on SALE materials; (2) techniques used; and (3) discussion of investigators' revised results. The study shows that nondestructive calorimetric assay of plutonium offers a viable alternative to traditional wet chemical techniques. For these samples, the precision ranged from 0.4 to 0.6% with biases less than 0.2%. Thus, for those materials where sampling errors are the predominant source of uncertainty, this technique can provide improved accuracy and precision while saving time and money as well as reducing the amount of liquid wastes to be handled. In addition, high resolution gamma-ray spectroscopy measurements of solids can provide isotopic analysis data in a cost effective and timely manner. The timeliness of the method can be especially useful to the plant operator for production control and quality control measurements

  10. Basic metallurgy for nondestructive testing

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    For this chapter, reader will be served with the basic knowledge on metallurgy for nondestructive testing. One the main application of nondestructive testing is to detect discontinuity of mass defect in metal. As we already know, metal are widely used in many application such as in building as a system, component and engineering product. Steel and iron are metal that usually used in industry, especially heavy industry such as gas and petroleum industry, chemistry, electric generation, automobile, and military device. Based on this, basic knowledge on metallurgy must need by NDT practitioner. The combination between metallurgy and datas from radiography testing can make radiographer good interpretation on quality of the metal inspected and can used to make a good decision either to accept or not certain product, system or components.

  11. Nondestructive inspection using neutron beams

    International Nuclear Information System (INIS)

    2013-01-01

    Neutron-abased experimental techniques such as neutronography, diffraction, or composition and elemental analysis are well established. They have important advantages in the non-destructive analysis of materials, making them a suitable option for quality-control protocols in industrial production lines. In addition, they are highly complementary to other non-destructive techniques, particularly X-ray analysis. Examples of industrial use include studies of pipes and ducts, concrete, or aeronautical components. Notwithstanding the above, the high cost associated with the construction and operation of the requisite neutron facilities has been an important limiting factor for their widespread use by the industrial sector. In this brief contribution, we explore the emerging (and already demonstrated) possibility of using compact, proton-accelerator-based neutron sources. these novel sources can be built and ran at a cost as low as a few ME, making them a competitive option to the more intense spallation or fission-based facilities for industrial applications. (Author)

  12. Influence of Neutron Spectra Unfolding Method on Fast Neutron Dose Determination

    International Nuclear Information System (INIS)

    Marinkovic, P.

    1991-01-01

    Full text: Accuracy of knowing the fast neutron spectra has great influence on equivalent dose determination. In usual fast neutron spectrum measurements with scintillation detectors based on proton recoil, the main difficulty is confidence of unfolding method. In former ones variance of obtained result is usually great and negative values are possible too, which does means that we don't now exactly is obtained neutron spectrum real one. The new unfolding method based on Shanon's information theory, which gives non-negative spectrum and relative low variance, is obtained and appropriate numerical code for application in fast neutron spectrometry based on proton recoil is realized. In this method principle of maximum entropy and maximum likelihood are used together. Unknown group density distribution functions, which are considered as desired normalized mean neutron group flux, are constl u cted using only constrain of knowing mean value. Obtained distributions are consistent to available information (counts in NCA from proton recoil), while being maximally noncommittal with respect to all other unknown circumstances. For maximum likelihood principle, distribution functions around mean value of counts in the channels of MCA are taken to be Gauss function shape. Optimal non-negative solution is searched by means of Lagrange parameter method. Nonlinear system of equations, is solved using gradient and Newton iterative algorithm. Error covariance matrix is obtained too. (author)

  13. Determination of gamma radiation lethal dose (LD50) and resveratrol cytotoxicity level in tumor cells line

    International Nuclear Information System (INIS)

    Magalhaes, Vanessa D.; Rogero, Sizue O.; Rogero, Jose R.; Cruz, Aurea S.

    2011-01-01

    Cancer is a disease with high incidence and it is considered a worldwide public health problem. Resveratrol is a polyphenol occurring naturally in a wide variety of plants according to response of ultraviolet radiation (UV) exposition or according to mechanical stress resulting of pathogens or chemical and physical agents. This polyphenol possesses a pharmacological activity of carcinogenesis inhibition in multiple levels. It also protects cells by scavenging the free radicals which are considered toxic products. These free radicals are formed of natural process of cell aging and also by incidence of ionizing radiation in the organism. Thus, resveratrol is considered as a cell radioprotector. On the other hand, in some elevated concentrations resveratrol may be considered as a radiosensitizing. The aim of this work was the determination of radiation lethal dose (LD 50 ) and also verifies the cytotoxicity level of resveratrol in tumor cells line: muco epidermoid pulmonary carcinoma cells (NCI-H292) and rhabdomyosarcoma cells (RD). The cytotoxicity test was performed by neutral red uptake assay. The results of resveratrol IC 50% in NCI-H292 cells was 192μM and in RD cells was 128μM; and RD cells gamma radiation LD 50 was 435Gy. (author)

  14. Determination of the optimal minimum radioiodine dose in patients with Graves' disease: a clinical outcome study

    Energy Technology Data Exchange (ETDEWEB)

    Howarth, D.; Tan, P.; Booker, J. [Pacific Medical Imaging, Newcastle, NSW (Australia); Epstein, M. [Dept. of Endocrinology, John Hunter Hospital, Newcastle, NSW (Australia); Lan, L. [High-Dependency Unit, St. George Hospital, Sydney, NSW (Australia)

    2001-10-01

    The study was performed under the auspices of the International Atomic Energy Commission, Vienna, Austria, with the aim of determining the optimal minimum therapeutic dose of iodine-131 for Graves' disease. The study was designed as a single-blinded randomised prospective outcome trial. Fifty-eight patients were enrolled, consisting of 50 females and 8 males aged from 17 to 75 years. Each patient was investigated by clinical assessment, biochemical and immunological assessment, thyroid ultrasound, technetium-99m thyroid scintigraphy and 24-h thyroid {sup 131}I uptake. Patients were then randomised into two treatment groups, one receiving 60 Gy and the other receiving 90 Gy thyroid tissue absorbed dose of radioiodine. The end-point markers were clinical and biochemical response to treatment. The median follow-up period was 37.5 months (range, 24-48 months). Among the 57 patients who completed final follow-up, a euthyroid state was achieved in 26 patients (46%), 27 patients (47%) were rendered hypothyroid and four patients (7%) remained hyperthyroid. Thirty-four patients (60%) remained hyperthyroid at 6 months after the initial radioiodine dose (median dose 126 MBq), and a total of 21 patients required additional radioiodine therapy (median total dose 640 MBq; range 370-1,485 MBq). At 6-month follow-up, of the 29 patients who received a thyroid tissue dose of 90 Gy, 17 (59%) remained hyperthyroid. By comparison, of the 28 patients who received a thyroid tissue dose of 60 Gy, 17 (61%) remained hyperthyroid. No significant difference in treatment response was found (P=0.881). At 6 months, five patients in the 90-Gy group were hypothyroid, compared to two patients in the 60-Gy group (P=0.246). Overall at 6 months, non-responders to low-dose therapy had a significantly larger thyroid gland mass (respective means: 35.9 ml vs 21.9 ml) and significantly higher levels of serum thyroglobulin (respective means: 597.6 {mu}g/l vs 96.9 {mu}g/l). Where low-dose radioiodine

  15. Nondestructive mechanical characterization of developing biological tissues using inflation testing.

    Science.gov (United States)

    Oomen, P J A; van Kelle, M A J; Oomens, C W J; Bouten, C V C; Loerakker, S

    2017-10-01

    One of the hallmarks of biological soft tissues is their capacity to grow and remodel in response to changes in their environment. Although it is well-accepted that these processes occur at least partly to maintain a mechanical homeostasis, it remains unclear which mechanical constituent(s) determine(s) mechanical homeostasis. In the current study a nondestructive mechanical test and a two-step inverse analysis method were developed and validated to nondestructively estimate the mechanical properties of biological tissue during tissue culture. Nondestructive mechanical testing was achieved by performing an inflation test on tissues that were cultured inside a bioreactor, while the tissue displacement and thickness were nondestructively measured using ultrasound. The material parameters were estimated by an inverse finite element scheme, which was preceded by an analytical estimation step to rapidly obtain an initial estimate that already approximated the final solution. The efficiency and accuracy of the two-step inverse method was demonstrated on virtual experiments of several material types with known parameters. PDMS samples were used to demonstrate the method's feasibility, where it was shown that the proposed method yielded similar results to tensile testing. Finally, the method was applied to estimate the material properties of tissue-engineered constructs. Via this method, the evolution of mechanical properties during tissue growth and remodeling can now be monitored in a well-controlled system. The outcomes can be used to determine various mechanical constituents and to assess their contribution to mechanical homeostasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Radon in indoor air of primary schools: determinant factors, their variability and effective dose.

    Science.gov (United States)

    Madureira, Joana; Paciência, Inês; Rufo, João; Moreira, André; de Oliveira Fernandes, Eduardo; Pereira, Alcides

    2016-04-01

    Radon is a radioactive gas, abundant in granitic areas, such as in the city of Porto at the north-east of Portugal. This gas is a recognized carcinogenic agent, being appointed by the World Health Organization as the leading cause of lung cancer after smoking. The aim of this preliminary survey was to determine indoor radon concentrations in public primary schools, to analyse the main factors influencing their indoor concentration levels and to estimate the effective dose in students and teachers in primary schools. Radon concentrations were measured in 45 classrooms from 13 public primary schools located in Porto, using CR-39 passive radon detectors for about 2-month period. In all schools, radon concentrations ranged from 56 to 889 Bq/m(3) (mean = 197 Bq/m(3)). The results showed that the limit of 100 Bq/m(3) established by WHO IAQ guidelines was exceeded in 92 % of the measurements, as well as 8 % of the measurements exceeded the limit of 400 Bq/m(3) established by the national legislation. Moreover, the mean annual effective dose was calculated as 1.25 mSv/y (ranging between 0.58 and 3.07 mSv/y), which is below the action level (3-10 mSv). The considerable variability of radon concentration observed between and within floors indicates a need to monitor concentrations in several rooms for each floor. A single radon detector for each room can be used, provided that the measurement error is considerably lower than variability of radon concentration between rooms. The results of the present survey will provide useful baseline data for adopting safety measures and dealing effectively with radiation emergencies. In particular, radon remediation techniques should be used in buildings located in the highest radon risk areas of Portugal. The results obtained in the current study concerning radon levels and their variations will be useful to optimize the design of future research surveys.

  17. Determination of Dose-Equivalent Response of A Typical Diamond Microdosimeter in Space Radiation Fields

    Directory of Open Access Journals (Sweden)

    firouz payervand

    2018-01-01

    Conclusion: The reasonable agreement between the dose equivalents calculated in this study and the results reported by other researchers confirmed that this type of microdosimeter could be a promising candidate suitable for the measurement of the dose equivalent in space radiation fields.

  18. Optimized computational method for determining the beta dose distribution using a multiple-element thermoluminescent dosimeter system

    International Nuclear Information System (INIS)

    Shen, L.; Levine, S.H.; Catchen, G.L.

    1987-01-01

    This paper describes an optimization method for determining the beta dose distribution in tissue, and it describes the associated testing and verification. The method uses electron transport theory and optimization techniques to analyze the responses of a three-element thermoluminescent dosimeter (TLD) system. Specifically, the method determines the effective beta energy distribution incident on the dosimeter system, and thus the system performs as a beta spectrometer. Electron transport theory provides the mathematical model for performing the optimization calculation. In this calculation, parameters are determined that produce calculated doses for each of the chip/absorber components in the three-element TLD system. The resulting optimized parameters describe an effective incident beta distribution. This method can be used to determine the beta dose specifically at 7 mg X cm-2 or at any depth of interest. The doses at 7 mg X cm-2 in tissue determined by this method are compared to those experimentally determined using an extrapolation chamber. For a great variety of pure beta sources having different incident beta energy distributions, good agreement is found. The results are also compared to those produced by a commonly used empirical algorithm. Although the optimization method produces somewhat better results, the advantage of the optimization method is that its performance is not sensitive to the specific method of calibration

  19. Determination of effective dose for workers hemodynamics service using double dosimetry

    International Nuclear Information System (INIS)

    Ruiz Lopez, M. A.; Lobato Munoz, M.; Jodar Lopez, C. A.; Ramirez Ros, J. C.; Jerez Sainz, M. I.; Pamos Urena, M.; Carrasco Rodriguez, J. L.

    2013-01-01

    The use of an additional dosimeter at the level of the neck above the lead apron we can provide an indication of the dose in the head (the Crystal dose). In addition, it is possible to combine the two readings of the dosimeter to provide an improved estimate of the effective dose. In the hemodynamics service of our Hospital we have maintained a worker for 3 years with the double dosimetry read monthly. With the readings from these dosimeters will do following algorithms, several estimates of the effective dose to see if, with working conditions that occur in this service, it would be necessary to extend this practice to the rest of the workers to get a better estimation of effective dose. (Author)

  20. Determination of key radionuclides and parameters related to dose from the Columbia River pathway

    International Nuclear Information System (INIS)

    Napier, B.A.

    1993-03-01

    A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. These scoping calculations may include some radionuclides and pathways that were included in the Phase 1 Columbia River pathway dose evaluations, as well as other potential exposure pathways being evaluated for possible inclusion in future Hanford Environmental Dose Reconstruction Project (HEDR) modeling efforts. This scoping calculation (Calculation 009) examines the contributions of numerous radionuclides to dose via environmental exposures and accumulation in water, fish, and other aquatic biota. Addressed in these calculations are the contributions to effective dose from (1) external exposure to contaminated river water, ( 2) ingestion of contaminated drinking water, and (3) ingestion of contaminated resident Columbia River fish. Additional information on contamination of anadromous fish and waterfowl is provided

  1. Nondestructive Assay Options for Spent Fuel Encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, Stephen J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jansson, Peter [Uppsala Univ. (Sweden)

    2014-10-02

    This report describes the role that nondestructive assay (NDA) techniques and systems of NDA techniques may have in the context of an encapsulation and deep geological repository. The potential NDA needs of an encapsulation and repository facility include safeguards, heat content, and criticality. Some discussion of the facility needs is given, with the majority of the report concentrating on the capability and characteristics of individual NDA instruments and techniques currently available or under development. Particular emphasis is given to how the NDA techniques can be used to determine the heat production of an assembly, as well as meet the dual safeguards needs of 1) determining the declared parameters of initial enrichment, burn-up, and cooling time and 2) detecting defects (total, partial, and bias). The report concludes with the recommendation of three integrated systems that might meet the combined NDA needs of the encapsulation/repository facility.

  2. Development and experimental validation of a tool to determine out-of-field dose in radiotherapy

    International Nuclear Information System (INIS)

    Bessieres, I.

    2013-01-01

    Over the last two decades, many technical developments have been achieved on intensity modulated radiotherapy (IMRT) and allow a better conformation of the dose to the tumor and consequently increase the success of cancer treatments. These techniques often reduce the dose to organs at risk close to the target volume; nevertheless they increase peripheral dose levels. In this situation, the rising of the survival rate also increases the probability of secondary effects expression caused by peripheral dose deposition (second cancers for instance). Nowadays, the peripheral dose is not taken into account during the treatment planning and no reliable prediction tool exists. However it becomes crucial to consider the peripheral dose during the planning, especially for pediatric cases. Many steps of the development of an accurate and fast Monte Carlo out-of-field dose prediction tool based on the PENELOPE code have been achieved during this PhD work. To this end, we demonstrated the ability of the PENELOPE code to estimate the peripheral dose by comparing its results with reference measurements performed on two experimental configurations (metrological and pre-clinical). During this experimental work, we defined a protocol for low doses measurement with OSL dosimeters. In parallel, we highlighted the slow convergence of the code for clinical use. Consequently, we accelerated the code by implementing a new variance reduction technique called pseudo-deterministic transport which is specifically with the objective of improving calculations in areas far away from the beam. This step improved the efficiency of the peripheral doses estimation in both validation configurations (by a factor of 20) in order to reach reasonable computing times for clinical application. Optimization works must be realized in order improve the convergence of our tool and consider a final clinical use. (author) [fr

  3. AXAOTHER XL -- A spreadsheet for determining doses for incidents caused by tornadoes or high-velocity straight winds

    International Nuclear Information System (INIS)

    Simpkins, A.A.

    1996-09-01

    AXAOTHER XL is an Excel Spreadsheet used to determine dose to the maximally exposed offsite individual during high-velocity straight winds or tornado conditions. Both individual and population doses may be considered. Potential exposure pathways are inhalation and plume shine. For high-velocity straight winds the spreadsheet has the capability to determine the downwind relative air concentration, however for the tornado conditions, the user must enter the relative air concentration. Theoretical models are discussed and hand calculations are performed to ensure proper application of methodologies. A section has also been included that contains user instructions for the spreadsheet

  4. Overview of double dosimetry procedures for the determination of the effective dose to the interventional radiology staff

    International Nuclear Information System (INIS)

    Jaervinen, H.; Buls, N.; Clerinx, P.; Jansen, J.; Miljanic, S.; Nikodemova, D.; Ranogajec-Komor, M.; D'Errico, F.

    2008-01-01

    In interventional radiology, for an accurate determination of effective dose to the staff, measurements with two dosemeters have been recommended, one located above and one under the protective apron. Such 'double dosimetry' practices and the algorithms used for the determination of effective dose were reviewed in this study by circulating a questionnaire and by an extensive literature search. The results indicated that regulations for double dosimetry almost do not exist and there is no firm consensus on the most suitable calculation algorithms. The calculation of effective dose is mainly based on the single dosemeter measurements, in which either personal dose equivalent, directly, (dosemeter below the apron) or a fraction of personal dose equivalent (dosemeter above the apron) is taken as an assessment of effective dose. The most recent studies suggest that there might not be just one double dosimetry algorithm that would be optimum for all interventional radiology procedures. Further investigations in several critical configurations of interventional radiology procedures are needed to assess the suitability of the proposed algorithms. (authors)

  5. Film techniques in radiotherapy for treatment verification, determination of patient exit dose, and detection of localization error

    International Nuclear Information System (INIS)

    Haus, A.G.; Marks, J.E.

    1974-01-01

    In patient radiation therapy, it is important to know that the diseased area is included in the treatment field and that normal anatomy is properly shielded or excluded. Since 1969, a film technique developed for imaging of the complete patient radiation exposure has been applied for treatment verification and for the detection and evaluation of localization errors that may occur during treatment. The technique basically consists of placing a film under the patient during the entire radiation exposure. This film should have proper sensitivity and contrast in the exit dose exposure range encountered in radiotherapy. In this communication, we describe how various exit doses fit the characteristic curve of the film; examples of films exposed to various exit doses; the technique for using the film to determine the spatial distribution of the absorbed exit dose; and types of errors commonly detected. Results are presented illustrating that, as the frequency of use of this film technique is increased, localization error is reduced significantly

  6. Phase space determination from measured dose data for intraoperative electron radiation therapy.

    Science.gov (United States)

    Herranz, E; Herraiz, J L; Ibáñez, P; Pérez-Liva, M; Puebla, R; Cal-González, J; Guerra, P; Rodríguez, R; Illana, C; Udías, J M

    2015-01-07

    A procedure to characterize beams of a medical linear accelerator for their use in Monte Carlo (MC) dose calculations for intraoperative electron radiation therapy (IOERT) is presented. The procedure relies on dose measurements in homogeneous media as input, avoiding the need for detailed simulations of the accelerator head. An iterative algorithm (EM-ML) has been employed to extract the relevant details of the phase space (PHSP) of the particles coming from the accelerator, such as energy spectra, spatial distribution and angle of emission of particles. The algorithm can use pre-computed dose volumes in water and/or air, so that the machine-specific tuning with actual data can be performed in a few minutes. To test the procedure, MC simulations of a linear accelerator with typical IOERT applicators and energies, have been performed and taken as reference. A solution PHSP derived from the dose produced by the simulated accelerator has been compared to the reference PHSP. Further, dose delivered by the simulated accelerator for setups not included in the fit of the PHSP were compared to the ones derived from the solution PHSP. The results show that it is possible to derive from dose measurements PHSP accurate for IOERT MC dose estimations.

  7. Conversion coefficients for determining organ doses in paediatric pelvis and hip joint radiography

    International Nuclear Information System (INIS)

    Seidenbusch, Michael C.; Schneider, Karl

    2014-01-01

    Knowledge of organ and effective doses achieved during paediatric X-ray examinations is an important prerequisite for assessment of radiation burden to the patient. Conversion coefficients for reconstruction of organ and effective doses from entrance doses for pelvis and hip joint radiographs of 0-, 1-, 5-, 10-, 15- and 30-year-old patients are provided regarding the Guidelines of Good Radiographic Technique of the European Commission. Using the personal computer program PCXMC developed by the Finnish Centre for Radiation and Nuclear Safety (Saeteilyturvakeskus STUK), conversion coefficients for conventional pelvis and hip joint radiographs were calculated by performing Monte Carlo simulations in mathematical hermaphrodite phantom models representing patients of different ages. The clinical variation of radiation field settings was taken into consideration by defining optimal and suboptimal standard field settings. Conversion coefficients for the reconstruction of organ doses in about 40 organs and tissues from measured entrance doses during pelvis and hip joint radiographs of 0-, 1-, 5-, 10-, 15- and 30-year-old patients were calculated for the standard sagittal beam projection and the standard focus detector distance of 115 cm. The conversion coefficients presented can be used for organ dose assessments from entrance doses measured during pelvis and hip joint radiographs of children and young adults with all field settings within the optimal and suboptimal standard field settings. (orig.)

  8. SU-G-201-06: Directional Low-Dose Rate Brachytherapy: Determination of the TG-43 Dose-Rate Constant Analog for a New Pd-103 Source

    Energy Technology Data Exchange (ETDEWEB)

    Aima, M; Culberson, W; Hammer, C; Micka, J; DeWerd, L [Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI (United States)

    2016-06-15

    Purpose: The aim of this work is to determine the TG-43 dose-rate constant analog for a new directional low-dose rate brachytherapy source based on experimental methods and comparison to Monte Carlo simulations. The CivaSheet™ is a new commercially available planar source array comprised of a variable number of discrete directional source elements called “CivaDots”. Given the directional nature and non-conventional design of the source, modifications to the AAPM TG-43 protocol for dosimetry are required. As a result, various parameters of the TG-43 dosimetric formalism have to be adapted to accommodate this source. This work focuses on the dose-rate constant analog determination for a CivaDot. Methods: Dose to water measurements of the CivaDot were performed in a polymethyl methacrylate phantom (20×20×12 cm{sup 3}) using thermoluminescent dosimeters (TLDs) and Gafchromic EBT3 film. The source was placed in the center of the phantom, and nine TLD micro-cubes were irradiated along its central axis at a distance of 1 cm. For the film measurements, the TLDs were substituted by a (3×3) cm{sup 2} EBT3 film. Primary air-kerma strength measurements of the source were performed using a variable-aperture free-air chamber. Finally, the source was modeled using the Monte Carlo N-Particle Transport Code 6. Results: Dose-rate constant analog observed for a total of eight CivaDots using TLDs and five CivaDots using EBT3 film was within ±7.0% and ±2.9% of the Monte Carlo predicted value respectively. The average difference observed was −4.8% and −0.1% with a standard deviation of 1.7% and 2.1% for the TLD and the film measurements respectively, which are both within the comparison uncertainty. Conclusion: A preliminary investigation to determine the doserate constant analog for a CivaDot was conducted successfully with good agreement between experimental and Monte Carlo based methods. This work will aid in the eventual realization of a clinically-viable dosimetric

  9. Dose to the Developing Dentition During Therapeutic Irradiation: Organ at Risk Determination and Clinical Implications

    International Nuclear Information System (INIS)

    Thompson, Reid F.; Schneider, Ralf A.; Albertini, Francesca; Lomax, Antony J.; Ares, Carmen; Goitein, Gudrun; Hug, Eugen B.

    2013-01-01

    Purpose: Irradiation of pediatric facial structures can cause severe impairment of permanent teeth later in life. We therefore focused on primary and permanent teeth as organs at risk, investigating the ability to identify individual teeth in children and infants and to correlate dose distributions with subsequent dental toxicity. Methods and Materials: We retrospectively reviewed 14 pediatric patients who received a maximum dose >20 Gy(relative biological effectiveness, RBE) to 1 or more primary or permanent teeth between 2003 and 2009. The patients (aged 1-16 years) received spot-scanning proton therapy with 46 to 66 Gy(RBE) in 23 to 33 daily fractions for a variety of tumors, including rhabdomyosarcoma (n=10), sarcoma (n=2), teratoma (n=1), and carcinoma (n=1). Individual teeth were contoured on axial slices from planning computed tomography (CT) scans. Dose-volume histogram data were retrospectively obtained from total calculated delivered treatments. Dental follow-up information was obtained from external care providers. Results: All primary teeth and permanent incisors, canines, premolars, and first and second molars were identifiable on CT scans in all patients as early as 1 year of age. Dose-volume histogram analysis showed wide dose variability, with a median 37 Gy(RBE) per tooth dose range across all individuals, and a median 50 Gy(RBE) intraindividual dose range across all teeth. Dental follow-up revealed absence of significant toxicity in 7 of 10 patients but severe localized toxicity in teeth receiving >20 Gy(RBE) among 3 patients who were all treated at <4 years of age. Conclusions: CT-based assessment of dose distribution to individual teeth is feasible, although delayed calcification may complicate tooth identification in the youngest patients. Patterns of dental dose exposure vary markedly within and among patients, corresponding to rapid dose falloff with protons. Severe localized dental toxicity was observed in a few patients receiving the

  10. Determination of the optimum irradiation dose for shelf-life of peas and cherry tomatoes

    International Nuclear Information System (INIS)

    Zaman, M. B.; Hayumbu, P.; Siwale, J.; Mutale, C.; Kabwe, L.

    1991-01-01

    Green peas (Pisum Sativum), cultivar (mangetout) and yellow cherry tomatoes (lycoperscum esculantum), cultivar (cerasiforme) were irradiated for different absorbed doses, and their physical characteristics observed under cold storage conditions, in order to extend their shelf lives. Results suggest that 580 Gy is the maximum optimum dose. At this dose the shelf life of cherry tomatoes is shown to be extended. No beneficial effect was recorded on the storage life of green peas. A good correlation was found between the degradation of chlorophill and the spread of spotting disease for this product. (author)., 19 refs., 2 tab

  11. Comparison of absorbed dose determinations using the IAEA dosimetry protocol and the ferrous sulphate dosimeter

    International Nuclear Information System (INIS)

    Mattsson, Olof

    1988-01-01

    In 1985 a comparison of different revised protocols for the dosimetry of high-energy photon and electron beams was published (Mattsson, 1985). The conclusions were that the agreement in absorbed dose to water determined using the different protocols is very good and that the agreement between ionization chamber and ferrous sulphate dosimetry is generally good. For electron beams the differences obtained with the ionization chamber and ferrous sulphate dosimeters were up to about 2%. The influence of the energy and angular distribution of the electron beams on the ionization chamber dosimetry is not fully considered in the dosimetry protocols. The basis for the ionization chamber dosimetry has recently been changed when the Bureau International des Poids et Mesures (BIPM) in 1986 changed the air-kerma standard. The reason was the adaption of the new stopping-power values reported in the ICRU Report No. 37. To achieve consistency in the ionization chamber dosimetry the interaction coefficients and correction factors given in the dosimetry protocols should also be based on the same set of stopping-power values. This is not the case with the protocols included in the comparison made by Mattsson. However, in the international code of practice by the International Atomic Energy Agency (IAEA, 1987) the new stopping-power values have been used. The formalism is the same as in most of the previous protocols. Mattsson et al. (1989) have shown that the differences in the various steps cancel out for the protocols published by NACP (1980) and by IAEA (1987) for cobalt-60 gamma quality. However, it is also of interest to investigate the influence of the new air-kerma standard and the new values on coefficients and factors given in the IAEA protocol for other beam qualities. Therefore, the data given by Mattsson (1985) have been recalculated using the new air-kerma standard and the IAEA protocol

  12. Determination of prescription dose for Cs-131 permanent implants using the BED formalism including resensitization correction

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wei, E-mail: wei.luo@uky.edu; Molloy, Janelle; Aryal, Prakash; Feddock, Jonathan; Randall, Marcus [Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536 (United States)

    2014-02-15

    Purpose: The current widely used biological equivalent dose (BED) formalism for permanent implants is based on the linear-quadratic model that includes cell repair and repopulation but not resensitization (redistribution and reoxygenation). The authors propose a BED formalism that includes all the four biological effects (4Rs), and the authors propose how it can be used to calculate appropriate prescription doses for permanent implants with Cs-131. Methods: A resensitization correction was added to the BED calculation for permanent implants to account for 4Rs. Using the same BED, the prescription doses with Au-198, I-125, and Pd-103 were converted to the isoeffective Cs-131 prescription doses. The conversion factor F, ratio of the Cs-131 dose to the equivalent dose with the other reference isotope (F{sub r}: with resensitization, F{sub n}: without resensitization), was thus derived and used for actual prescription. Different values of biological parameters such as α, β, and relative biological effectiveness for different types of tumors were used for the calculation. Results: Prescription doses with I-125, Pd-103, and Au-198 ranging from 10 to 160 Gy were converted into prescription doses with Cs-131. The difference in dose conversion factors with (F{sub r}) and without (F{sub n}) resensitization was significant but varied with different isotopes and different types of tumors. The conversion factors also varied with different doses. For I-125, the average values of F{sub r}/F{sub n} were 0.51/0.46, for fast growing tumors, and 0.88/0.77 for slow growing tumors. For Pd-103, the average values of F{sub r}/F{sub n} were 1.25/1.15 for fast growing tumors, and 1.28/1.22 for slow growing tumors. For Au-198, the average values of F{sub r}/F{sub n} were 1.08/1.25 for fast growing tumors, and 1.00/1.06 for slow growing tumors. Using the biological parameters for the HeLa/C4-I cells, the averaged value of F{sub r} was 1.07/1.11 (rounded to 1.1), and the averaged value of F

  13. Determination of prescription dose for Cs-131 permanent implants using the BED formalism including resensitization correction

    International Nuclear Information System (INIS)

    Luo, Wei; Molloy, Janelle; Aryal, Prakash; Feddock, Jonathan; Randall, Marcus

    2014-01-01

    Purpose: The current widely used biological equivalent dose (BED) formalism for permanent implants is based on the linear-quadratic model that includes cell repair and repopulation but not resensitization (redistribution and reoxygenation). The authors propose a BED formalism that includes all the four biological effects (4Rs), and the authors propose how it can be used to calculate appropriate prescription doses for permanent implants with Cs-131. Methods: A resensitization correction was added to the BED calculation for permanent implants to account for 4Rs. Using the same BED, the prescription doses with Au-198, I-125, and Pd-103 were converted to the isoeffective Cs-131 prescription doses. The conversion factor F, ratio of the Cs-131 dose to the equivalent dose with the other reference isotope (F r : with resensitization, F n : without resensitization), was thus derived and used for actual prescription. Different values of biological parameters such as α, β, and relative biological effectiveness for different types of tumors were used for the calculation. Results: Prescription doses with I-125, Pd-103, and Au-198 ranging from 10 to 160 Gy were converted into prescription doses with Cs-131. The difference in dose conversion factors with (F r ) and without (F n ) resensitization was significant but varied with different isotopes and different types of tumors. The conversion factors also varied with different doses. For I-125, the average values of F r /F n were 0.51/0.46, for fast growing tumors, and 0.88/0.77 for slow growing tumors. For Pd-103, the average values of F r /F n were 1.25/1.15 for fast growing tumors, and 1.28/1.22 for slow growing tumors. For Au-198, the average values of F r /F n were 1.08/1.25 for fast growing tumors, and 1.00/1.06 for slow growing tumors. Using the biological parameters for the HeLa/C4-I cells, the averaged value of F r was 1.07/1.11 (rounded to 1.1), and the averaged value of F n was 1.75/1.18. F r of 1.1 has been applied to

  14. Determination of the contribution of livestock water ingestion to dose from the cow-milk pathway

    International Nuclear Information System (INIS)

    Ikenberry, T.A.

    1992-12-01

    As part of the Hanford Environmental Dose Reconstruction (HEDR) Project, a series of calculations has been undertaken to evaluate the absolute and relative contribution of different exposure pathways to thyroid doses that may have been received by individuals living in the vicinity of the Hanford Site. These evaluations include some pathways that were included in the Phase I air-pathway dose evaluations (HEDR staff 1991, page xx), as well as other potential exposure pathways being evaluated for possible inclusion in the future HEDR modeling efforts. This calculation (002) examined the possible doses that may have been received by individuals who drank milk from cows that drank from sources of water (stock tanks and farm ponds) exposed to iodine-131 in the atmosphere during 1945

  15. Determination of electron clinical spectra from percentage depth dose (PDD) curves by classical simulated annealing method

    International Nuclear Information System (INIS)

    Visbal, Jorge H. Wilches; Costa, Alessandro M.

    2016-01-01

    Percentage depth dose of electron beams represents an important item of data in radiation therapy treatment since it describes the dosimetric properties of these. Using an accurate transport theory, or the Monte Carlo method, has been shown obvious differences between the dose distribution of electron beams of a clinical accelerator in a water simulator object and the dose distribution of monoenergetic electrons of nominal energy of the clinical accelerator in water. In radiotherapy, the electron spectra should be considered to improve the accuracy of dose calculation since the shape of PDP curve depends of way how radiation particles deposit their energy in patient/phantom, that is, the spectrum. Exist three principal approaches to obtain electron energy spectra from central PDP: Monte Carlo Method, Direct Measurement and Inverse Reconstruction. In this work it will be presented the Simulated Annealing method as a practical, reliable and simple approach of inverse reconstruction as being an optimal alternative to other options. (author)

  16. A Topographically and anatomically unified phantom model for organ dose determination in radiation hygiene

    International Nuclear Information System (INIS)

    Servomaa, A.; Rannikko, S.; Ermakov, I.; Masarskyi, L.; Saltukova, L.

    1989-08-01

    The effective dose equivalent is used as a risk-related factor for assessing radiation impact on patients. In order to assess the effective dose equivalent, data on organ doses in several organs are needed. For calculation of the collective effective dose equivalent, data on the sex and size distribution of the exposed population are also needed. A realistic phantom model based on the Alderson-Rando anatomical phantom has been developed for these purposes. The phantom model includes 22 organs and takes into account the deflections due to sex, height, weight and other anatomical features. Coordinates of the outer contours of inner organs are given in different slabs of the phantom. The images of cross sections of different slabs realistically depict the distribution of the organs in the phantom. Statistics about height and weight distribution as a function of the age of the Finnish population are also given. (orig.)

  17. Determination of alpha dose rate profile at the HLW nuclear glass/water interface

    Energy Technology Data Exchange (ETDEWEB)

    Mougnaud, S., E-mail: sarah.mougnaud@cea.fr [CEA Marcoule, DEN/DTCD/SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Tribet, M.; Rolland, S. [CEA Marcoule, DEN/DTCD/SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Renault, J.-P. [CEA Saclay, NIMBE UMR 3685 CEA/CNRS, 91191 Gif-sur-Yvette cedex (France); Jégou, C. [CEA Marcoule, DEN/DTCD/SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France)

    2015-07-15

    Highlights: • The nuclear glass/water interface is studied. • The way the energy of alpha particles is deposited is modeled using MCNPX code. • A model giving dose rate profiles at the interface using intrinsic data is proposed. • Bulk dose rate is a majoring estimation in alteration layer and in surrounding water. • Dose rate is high in small cracks; in larger ones irradiated volume is negligible. - Abstract: Alpha irradiation and radiolysis can affect the alteration behavior of High Level Waste (HLW) nuclear glasses. In this study, the way the energy of alpha particles, emitted by a typical HLW glass, is deposited in water at the glass/water interface is investigated, with the aim of better characterizing the dose deposition at the glass/water interface during water-induced leaching mechanisms. A simplified chemical composition was considered for the nuclear glass under study, wherein the dose rate is about 140 Gy/h. The MCNPX calculation code was used to calculate alpha dose rate and alpha particle flux profiles at the glass/water interface in different systems: a single glass grain in water, a glass powder in water and a water-filled ideal crack in a glass package. Dose rate decreases within glass and in water as distance to the center of the grain increases. A general model has been proposed to fit a dose rate profile in water and in glass from values for dose rate in glass bulk, alpha range in water and linear energy transfer considerations. The glass powder simulation showed that there was systematic overlapping of radiation fields for neighboring glass grains, but the water dose rate always remained lower than the bulk value. Finally, for typical ideal cracks in a glass matrix, an overlapping of irradiation fields was observed while the crack aperture was lower than twice the alpha range in water. This led to significant values for the alpha dose rate within the crack volume, as long as the aperture remained lower than 60 μm.

  18. Genetic effects induced by neutrons in Drosophila melanogaster I. Determination of absorbed dose

    International Nuclear Information System (INIS)

    Delfin, A.; Paredes, L.C.; Zambrano, F.; Guzman-Rincon, J.; Urena-Nunez, F.

    2001-01-01

    A method to obtain the absorbed dose in Drosophila melanogaster irradiated in the thermal column facility of the Triga Mark III Reactor has been developed. The method is based on the measurements of neutron activation of gold foils produced by neutron capture to obtain the neutron fluxes. These fluxes, combined with the calculations of kinetic energy released per unit mass, enables one to obtain the absorbed doses in Drosophila melanogaster

  19. Dose determination algorithms for a nearly tissue equivalent multi-element thermoluminescent dosimeter

    International Nuclear Information System (INIS)

    Moscovitch, M.; Chamberlain, J.; Velbeck, K.J.

    1988-01-01

    In a continuing effort to develop dosimetric systems that will enable reliable interpretation of dosimeter readings in terms of the absorbed dose or dose-equivalent, a new multi-element TL dosimeter assembly for Beta and Gamma dose monitoring has been designed. The radiation-sensitive volumes are four LiF-TLD elements, each covered by its own unique filter. For media-matching, care has been taken to employ nearly tissue equivalent filters of thicknesses of 1000 mg/cm 2 and 300 mg/cm 2 for deep dose and dose to the lens-of-the-eye measurements respectively. Only one metal filter (Cu) is employed to provide low energy photon discrimination. A Thin TL element (0.09 mm thick) is located behind an open window designed to improve the energy under-response to low energy beta rays and to provide closer estimate of the shallow dose equivalent. The deep and shallow dose equivalents are derived from the correlation of the response of the various TL elements to the above quantities through computations based on previously defined relationships obtained from experimental results. The theoretical formalization for the dose calculation algorithms is described in detail, and provides a useful methodology which can be applied to different tissue-equivalent dosimeter assemblies. Experimental data has been obtained by performing irradiation according to the specifications established by DOELAP, using 27 types of pure and mixed radiation fields including Cs-137 gamma rays, low energy photons down to 20 keV, Sr/Y-90, Uranium, and Tl-204 beta particles

  20. Determination of the tissue inhomogeneity correction in high dose rate Brachytherapy for Iridium-192 source

    Directory of Open Access Journals (Sweden)

    Barlanka Ravikumar

    2012-01-01

    Full Text Available In Brachytherapy treatment planning, the effects of tissue heterogeneities are commonly neglected due to lack of accurate, general and fast three-dimensional (3D dose-computational algorithms. In performing dose calculations, it is assumed that the tumor and surrounding tissues constitute a uniform, homogeneous medium equivalent to water. In the recent past, three-dimensional computed tomography (3D-CT based treatment planning for Brachytherapy applications has been popularly adopted. However, most of the current commercially available planning systems do not provide the heterogeneity corrections for Brachytherapy dosimetry. In the present study, we have measured and quantified the impact of inhomogeneity caused by different tissues with a 0.015 cc ion chamber. Measurements were carried out in wax phantom which was employed to measure the heterogeneity. Iridium-192 (192 Ir source from high dose rate (HDR Brachytherapy machine was used as the radiation source. The reduction of dose due to tissue inhomogeneity was measured as the ratio of dose measured with different types of inhomogeneity (bone, spleen, liver, muscle and lung to dose measured with homogeneous medium for different distances. It was observed that different tissues attenuate differently, with bone tissue showing maximum attenuation value and lung tissue resulting minimum value and rest of the tissues giving values lying in between those of bone and lung. It was also found that inhomogeneity at short distance is considerably more than that at larger distances.

  1. Determination of line edge roughness in low dose top-down scanning electron microscopy images

    Science.gov (United States)

    Verduin, T.; Kruit, P.; Hagen, C. W.

    2014-04-01

    We investigated off-line metrology for LER determination in low-dose SEM images to reduce the acquisition time and the risk of shrinkage. Our first attempts are based on filtering noisy (experimental) SEM images and use peak detection to measure the edge displacements and calculating the discrete PSD. However, the result of the filtering is that the power spectrum of the filter leaks into the PSD. So it is better to avoid a filter at all. We subsequently developed a method to detect edge displacements without the use of a filter. This method considers the signal profile of a SEM by integrating an experimental image of lines in the direction of the edges. The signal profile of an isolated edge is modeled as two merged Gaussians. This signal profile is then fitted against the raw (unfiltered) data of the edge pattern using an interior trust-region-reflective minimization procedure. This gives the edge displacements without the use of a filter and a filter-free version of the discrete PSD is obtained. The determination of edge displacements without the use of a filter, enables us to study how much noise is acceptable and still determine LER. To answer this question we generate random lines using the model of Palasantzas and the algorithm of Thorsos. This gives random generated edge displacements for typical values of experimental lines for the parameters of the model: 2 μm long lines (256 pixels), a correlation length ξ of 25 nm and a roughness exponent of 0.75. A noise-free top-down SEM-like image of lines is created by shifting the profile signal according to the random generated edge displacements. The image is further processed by adding Poisson-distributed noise. We consider three noise cases where the average electron density is about 2, 20 and 200 electrons per pixel. This corresponds to a charge density of (in respective order) 10 μC/cm2, 100 μC/cm2 and 1000 μC/cm2. The edge displacements of the random generated images are determined using our new

  2. The 30 Years of the Korean Society for Nondestructive Testing

    International Nuclear Information System (INIS)

    2010-05-01

    The contents of this book are development of nondestructive testings; the origin of nondestructive testing, history of Korea on nondestructive testing and present condition of nondestructive testing in Korea, history of society, activity of society; structure and activity of society, publication of society academic project, educational work, international exchange, and the future and direction of development of the Korean society for nondestructive testing.

  3. Non-Destructive Inspection Lab (NDI)

    Data.gov (United States)

    Federal Laboratory Consortium — The NDI specializes in applied research, development and performance of nondestructive inspection procedures (flourescent penetrant, magnetic particle, ultrasonics,...

  4. Verification of the absorbed dose values determined with plane parallel ionization chambers in therapeutic electron beams using ferrous sulfate dosimetry

    International Nuclear Information System (INIS)

    Plaetsen, A. van der; Thierens, H.; Palmans, H.

    2000-01-01

    Absolute and relative dosimetry measurements in clinical electron beams using different detectors were performed at a Philips SL18 accelerator. For absolute dosimetry, ionization chamber measurements with the PTW Markus and PTW Roos plane parallel chambers were performed in water following the recommendations of the TRS-381 Code of Practice, using different options for chamber calibration. The dose results obtained with these ionization chambers using the electron beam calibration method were compared with the dose response of the ferrous sulphate (Fricke) chemical dosimeter. The influence of the choice of detector type on the determination of physical quantities necessary for absolute dose determination was investigated and discussed. Results for d max , R 50 and R p were in agreement within statistical uncertainties when using a diode, diamond or plane parallel chamber. The effective point of measurement for the Markus chamber is found to be shifted 0.5 mm from the front surface of the cavity. Fluence correction factors, h m , for dose determination in electron beams using a PMMA phantom were determined experimentally for both plane parallel chamber types. (author)

  5. Determination of permissible doses under the provisions of the regulations on installation and operation of reactors for power generation

    International Nuclear Information System (INIS)

    1979-01-01

    The determination is defined under the regulations on installation and operation of reactors for power generation. In the controlled area exterior radiation dose shall be 30 mili-rem for a week by the Minister of International Trade and Industry. The concentrations of radioactive materials in the air or under the water shall be permissible concentrations specified for the employees multiplied by 0.75 in average for a week. The densities of radioactive materials on the surface of the things contaminated by such materials shall be 1/10 of permissible surface densities stipulated in the table attached. Permissible exposure dose outside the inspected surrounding area is 0.5 rem for a year. Permissible surface densities are included in the table attached. Permissible accumulative dose for the employees is the figure (unit rem) calculated by the formula D = 5(N-18), when D means permissible accumulative dose and N number of the age. Permissible exposure dose is 3 rem for 3 months for the employees, 1.5 rem for a year for persons other than the employees and 12 rem for the urgent work. Permissible concentrations are defined in detail for the employees and outside the inspected surrounding area. Calculation of exposure dose in the case of interior exposure is particularly provided for. (Okada, K.)

  6. Determination of gonad doses during robotic stereotactic radiosurgery for various tumor sites

    International Nuclear Information System (INIS)

    Zorlu, Faruk; Dugel, Gozde; Ozyigit, Gokhan; Hurmuz, Pervin; Cengiz, Mustafa; Yildiz, Ferah; Akyol, Fadil; Gurkaynak, Murat

    2013-01-01

    Purpose: The authors evaluated the absorbed dose received by the gonads during robotic stereotactic radiosurgery (SRS) for the treatment of different tumor localizations. Methods: The authors measured the gonad doses during the treatment of head and neck, thoracic, abdominal, or pelvic tumors in both RANDO phantom and actual patients. The computerized tomography images were transferred to the treatment planning system. The contours of tumor and critical organs were delineated on each slice, and treatment plans were generated. Measurements for gonad doses were taken from the geometric projection of the ovary onto the skin for female patients, and from the scrotal skin for male patients by attaching films and Thermoluminescent dosimeters (TLDs). SRS was delivered with CyberKnife (Accuray Inc., Sunnyvale, CA). Results: The median gonadal doses with TLD and film dosimeter in actual patients were 0.19 Gy (range, 0.035–2.71 Gy) and 0.34 Gy (range, 0.066–3.18 Gy), respectively. In the RANDO phantom, the median ovarian doses with TLD and film dosimeter were 0.08 Gy (range, 0.03–0.159 Gy) and 0.05 Gy (range, 0.015–0.13 Gy), respectively. In the RANDO phantom, the median testicular doses with TLD and film dosimeter were 0.134 Gy (range 0.056–1.97 Gy) and 0.306 Gy (range, 0.065–2.25 Gy). Conclusions: Gonad doses are below sterility threshold in robotic SRS for different tumor localizations. However, particular attention should be given to gonads during robotic SRS for pelvic tumors.

  7. Determination of gonad doses during robotic stereotactic radiosurgery for various tumor sites

    Energy Technology Data Exchange (ETDEWEB)

    Zorlu, Faruk; Dugel, Gozde; Ozyigit, Gokhan; Hurmuz, Pervin; Cengiz, Mustafa; Yildiz, Ferah; Akyol, Fadil; Gurkaynak, Murat [Hacettepe University Faculty of Medicine, Department of Radiation Oncology, Ankara 06100 (Turkey)

    2013-04-15

    Purpose: The authors evaluated the absorbed dose received by the gonads during robotic stereotactic radiosurgery (SRS) for the treatment of different tumor localizations. Methods: The authors measured the gonad doses during the treatment of head and neck, thoracic, abdominal, or pelvic tumors in both RANDO phantom and actual patients. The computerized tomography images were transferred to the treatment planning system. The contours of tumor and critical organs were delineated on each slice, and treatment plans were generated. Measurements for gonad doses were taken from the geometric projection of the ovary onto the skin for female patients, and from the scrotal skin for male patients by attaching films and Thermoluminescent dosimeters (TLDs). SRS was delivered with CyberKnife (Accuray Inc., Sunnyvale, CA). Results: The median gonadal doses with TLD and film dosimeter in actual patients were 0.19 Gy (range, 0.035-2.71 Gy) and 0.34 Gy (range, 0.066-3.18 Gy), respectively. In the RANDO phantom, the median ovarian doses with TLD and film dosimeter were 0.08 Gy (range, 0.03-0.159 Gy) and 0.05 Gy (range, 0.015-0.13 Gy), respectively. In the RANDO phantom, the median testicular doses with TLD and film dosimeter were 0.134 Gy (range 0.056-1.97 Gy) and 0.306 Gy (range, 0.065-2.25 Gy). Conclusions: Gonad doses are below sterility threshold in robotic SRS for different tumor localizations. However, particular attention should be given to gonads during robotic SRS for pelvic tumors.

  8. Fieldable computer system for determining gamma-ray pulse-height distributions, flux spectra, and dose rates from Little Boy

    International Nuclear Information System (INIS)

    Moss, C.E.; Lucas, M.C.; Tisinger, E.W.; Hamm, M.E.

    1984-01-01

    Our system consists of a LeCroy 3500 data acquisition system with a built-in CAMAC crate and eight bismuth-germanate detectors 7.62 cm in diameter and 7.62 cm long. Gamma-ray pulse-height distributions are acquired simultaneously for up to eight positions. The system was very carefully calibrated and characterized from 0.1 to 8.3 MeV using gamma-ray spectra from a variety of radioactive sources. By fitting the pulse-height distributions from the sources with a function containing 17 parameters, we determined theoretical repsonse functions. We use these response functions to unfold the distributions to obtain flux spectra. A flux-to-dose-rate conversion curve based on the work of Dimbylow and Francis is then used to obtain dose rates. Direct use of measured spectra and flux-to-dose-rate curves to obtain dose rates avoids the errors that can arise from spectrum dependence in simple gamma-ray dosimeter instruments. We present some gamma-ray doses for the Little Boy assembly operated at low power. These results can be used to determine the exposures of the Hiroshima survivors and thus aid in the establishment of radation exposure limits for the nuclear industry

  9. Nondestructive testing for bridge diagnosis

    International Nuclear Information System (INIS)

    Oshima, Toshiyuki; Mikami, Shuichi; Yamazaki, Tomoyuki

    1997-01-01

    There are many motivations for bridge diagnosis using Nondestructive testing (NDT) to monitor its integrity. The measured frequency and damping on real bridge are compared in one figure as a function of span length and general aspects are explained. These date were measured in every construction of bridges and applied to design new bridges. Ultrasonic testing is also well used for concrete and steel members mainly to detect internal damages or delaminations. Detail analysis on reflected waves gives us more accurate information about the defect. Experimental results are shown as examples in this paper.

  10. Nondestructive analysis of irradiated fuels

    International Nuclear Information System (INIS)

    Dudey, N.D.; Frick, D.C.

    1977-01-01

    The principal nondestructive examination techniques presently used to assess the physical integrity of reactor fuels and cladding materials include gamma-scanning, profilometry, eddy current, visual inspection, rod-to-rod spacing, and neutron radiography. LWR fuels are generally examined during annual refueling outages, and are conducted underwater in the spent fuel pool. FBR fuels are primarily examined in hot cells after fuel discharge. Although the NDE techniques are identical, LWR fuel examinations emphasize tests to demonstrate adherence to technical specification and reliable fuel performance; whereas, FBR fuel examinations emphasize aspects more related to the relative performance of different types of fuel and cladding materials subjected to variable irradiation conditions

  11. Nondestructive evaluation ultrasonic methods for construction materials

    International Nuclear Information System (INIS)

    Chilibon, I.; Zisu, T.; Raetchi, V.

    2002-01-01

    The paper presents some ultrasonic methods for evaluation of physical-mechanical properties of construction materials (bricks, concrete, BCA), such as: pulse method, examination methods, and direct measurement of the propagation velocity and impact-echo method. Utilizing these nondestructive evaluation ultrasonic methods it can be determined the main material parameters and material characteristics (elasticity coefficients, density, propagation velocity, ultrasound attenuation, etc.) of construction materials. These method are suitable for construction materials because the defectoscopy methods for metallic materials cannot be utilized, due to its rugged and non-homogeneous structures and grate attenuation coefficients of ultrasound propagation through materials. Also, the impact-echo method is a technique for flaw detection in concrete based on stress wave propagation. Studies have shown that the impact-echo method is effective for locating voids, honeycombing, delaminating, depth of surface opening cracks, and measuring member thickness

  12. Dose rate reduction using epoxy mixed lead shielding: experimental and theoretical determination of its shielding effectiveness

    International Nuclear Information System (INIS)

    Yadav, R.K.B.; Prasad, S.K.; Babu, K.S.; Hardiya, M.R.; Ullas, O.P.

    2010-01-01

    Full text: High background radiation field exists in Water Treatment Area (WTA) of Rod Cutting Building (RCB) in Cirus due to beta, gamma contamination on its floor. The high contamination on sides of wall and on floor is primarily due to deposition of activity generated during the regeneration of old mixed bed cartridges earlier (before year 1985) and presently due to deposition of contaminants by sump overflowing, wastes generated during maintenance/servicing of circulating pumps. RCB-WTA contribution to collective dose in present situation is up to 30% of the total collective dose of Cirus. Various options such as chipping of top layer of concrete floor of a sample area, in-situ placing of slab of cement and lead shot mixture were considered. In this case the man-rem consumption was high as radiation dose rate on concrete chip was 0.4 mGy/h and air activity generated was high, that too long lived with 137 Cs-as main constituent. The dose reduction factor was 1.7. In the second option the reduction in dose rate was insignificant and in-situ pouring of concrete consumed high collective dose. Hence above two options were not acceptable. Therefore the idea of tiling the contaminated floor with prefabricated epoxy mixed lead shots was accepted from ALARA point of view. It was concluded that pre-fabricated slabs of epoxy mixed lead slab of 25 mm thickness can be laid in RCB area to achieve a dose rate reduction factor of approximately five at a height of 30 cm above floor. This will result in a reduction of Person-mSv consumption in RCB by a factor of 5-10. These slabs of different thickness were fabricated outside RCB and were tested for shielding effectiveness experimentally by using radiation source and theoretically using MCNP code. Dose reduction factor of five for a point source, obtained experimentally for epoxy mixed lead shots was very near to value obtained by theoretical simulation. An extended calculation for an area source using this MCNP model gives a

  13. Determination of gamma ray doses suitable for mutation induction in garlic (Allium sativum L.)

    International Nuclear Information System (INIS)

    Al-Safadi, Bassam; Ayyoubi, Zouhair

    1993-04-01

    Garlic (Allium sativum L.) cloves were exposed to different doses of gamma radiation (Control, 100, 250, 500, 750, and 1000 rads). The cloves were planted in 4 replicates at Deer Alhajar station of the Dept. of Radiation Agriculture. Number of surviving plants was recorded at 2 months after planting and at harvest. Length of foliage was measured at harvest time and weight of cloves was taken two weeks after harvest. Visual readings in the field on plant shape and leaf color were also taken. The results indicated a negative effect of gamma radiation on plant survival especially at doses of 750 and 1000 rads where no plants survived until harvest. Plant length and clove weight were reduced even at 500 rad dose. Percentage of yellow and necrotic plants increased with increasing gamma ray dosage. No stimulation of plant growth was noticed as a result of irradiation with low doses of gamma rays. Treatment with 500 rads of gamma radiation was considered the best among tested doses for garlic mutagenesis (Using cloves) since it gave acceptable rate of survival and morphologic variation. (author). 14 refs., 4 figs

  14. Determinação não destrutiva do nitrogênio total em plantas por espectroscopia de reflectância difusa no infravermelho próximo Non-destructive determination of total nitrogen in plants by diffuse reflectance near infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Kássio M. G. Lima

    2008-01-01

    Full Text Available Diffuse reflectance near-infrared (DR-NIR spectroscopy associated with partial least squares (PLS multivariate calibration is proposed for a direct, non-destructive, determination of total nitrogen in wheat leaves. The procedure was developed for an Analytical Instrumental Analysis course, carried out at the Institute of Chemistry of the State University of Campinas. The DR-NIR results are in good agreement with those obtained by the Kjeldhal standard procedure, with a relative error of less than ± 3% and the method may be used for teaching purposes as well as for routine analysis.

  15. Aerosol particle size does not predict pharmacokinetic determined lung dose in children

    DEFF Research Database (Denmark)

    Bønnelykke, Klaus; Chawes, Bo L K; Vindfeld, Signe

    2013-01-01

    In vitro measures of aerosol particles size, such as the fine particle mass, play a pivotal role for approval of inhaled anti-asthmatic drugs. However, the validity as a measure of dose to the lungs in children lacks evidence. In this study we investigated for the first time the association between...... an in vivo estimate of lung dose of inhaled drug in children and the corresponding particle size segments assessed ex vivo. Lung dose of fluticasone propionate after inhalation from a dry powder inhaler (Diskus®) was studied in 23 children aged 4-7 and 12-15 years with mild asthma. Six-hour pharmacokinetics...... was assessed after single inhalation. The corresponding emitted mass of drug in segments of aerosol particle size was assessed ex vivo by replicating the inhalation flows recorded by transducers built into the Diskus® inhaler and re-playing them in a breathing simulator. There was no correlation between any...

  16. Three-dimensional determination of absorbed dose by spectrophotometric analysis of ferrous-sulphate agarose gel

    International Nuclear Information System (INIS)

    Gambarini, G.; Gomarasca, G.; Marchesini, R.; Pecci, A.; Pirola, L.; Tomatis, S.

    1999-01-01

    We describe a technique to obtain three-dimensional (3-D) imaging of an absorbed dose by optical transmittance measurements of phantoms composed by agarose gel in which a ferrous sulphate and xylenol orange solution are incorporated. The analysis of gel samples is performed by acquiring transmittance images with a system based on a CCD camera provided with an interference filter matching the optical absorption peak of interest. The proposed technique for 3-D measurements of an absorbed dose is based on the imaging of phantoms composed of sets of properly piled up gel slices. The slice thickness was optimized in order to obtain a good image contrast as well as a good in-depth spatial resolution. To test the technique, a phantom has been irradiated with a collimated γ-beam and then analysed. Proper software was adapted in order to visualise the images of all slices and to attain the 2-D profiles of the dose absorbed by each slice

  17. Dose rate determinations in the Portuguese Gamma Irradiation Facility: Monte Carlo simulations and measurements

    International Nuclear Information System (INIS)

    Oliveira, C.; Salgado, J.; Ferro de Carvalho, A.

    2000-01-01

    A simulation study of the Portuguese Gamma Irradiation Facility, UTR, has been carried out using the MCNP code. The work focused on the optimisation of the dose distribution inside the irradiation cell, dose calculations inside irradiated samples and dose calculations in critical points for protection purposes. Calculations were carried out at points inside and outside the irradiation cell, where different behaviour was expected (distance from the source, radiation absorption and scattering in irradiator structure and walls). The contributions from source, irradiator structure, sample material, carriers, walls, ceiling and floor to the photon spectra and air kerma at those points are reported and discussed. Air kerma measurements were also carried out using an ionisation chamber. Good agreement was found between experimental and calculated air kermas. (author)

  18. Uncertainty analysis in the determination of absorbed dose in water by Fricke chemical dosimetry

    International Nuclear Information System (INIS)

    Vasconcelos, Fabia; Aguirre, Eder Aguirre

    2016-01-01

    This work studies the calculations of uncertainties and the level of confidence that involves the process for obtaining the dose absorbed in water using the method of Fricke dosimetry, developed at Laboratorio de Ciencias Radiologicas (LCR). Measurements of absorbance of samples Fricke, irradiated and non-irradiated is going to use in order to calculate the respective sensitivity coefficients, along with the expressions of the calculation of Fricke dose and the absorbed dose in water. Those expressions are used for calculating the others sensitivity coefficients from the input variable. It is going to use the combined uncertainty and the expanded uncertainty, with a level of confidence of 95.45%, in order to report the uncertainties of the measurement. (author)

  19. Determination of the sterilizing gamma radiation dose of 60Co to ACANTHOSCELIDES OBTECTUS imagos (col. bruchidae)

    International Nuclear Information System (INIS)

    Arthur, V.; Wiendl, F.M.; Sgrillo, R.B.; Campanhola, C.

    1980-01-01

    This paper relates the results of experiments dealing with irradiation of adults of Acanthoscelides obtectus (Say, 1831). The insects were irradiated with doses of 0 (control), 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 20 krad gamma radiation of a 60 Co source. After irradiation, the adults were kept for observation on beans (Phaseolus vulgaris) var. Jalo, in a controlled environmen t chamber at 30 +- 1 0 C and 70 +- 5% relative humidity. Continuous weighing at weekly intervals was done 22 times, showing, by weight loss in percent, that the sterilizing dose for adults was 10,65 krad. It could also be observed that losses of less than 0,5% occured at 9 krad. For a possible employment on commercial scale, the ideal radiation dose for bean desinfestation would be 10 krad, after which no weight loss occurrence. (Author) [pt

  20. A MATHEMATICAL APPROACH TO ECONOMY OF EXPERIMENT IN DETERMINATIONS OF THE DIFFERENTIAL DOSE ALBEDO OF GAMMA RAYS

    Energy Technology Data Exchange (ETDEWEB)

    Shoemaker, N. F.; Huddleston, C. M.

    1962-12-10

    Treatments of the differential dose albedo of gamma rays on concrete have supposed that the albedo value is a function of: the energy of the incident gamma radiation, the polar angle of incidence, the polar angle of reflection (or scatter), and the azimuthal angle of reflection. It is demonstrated that, if certain reasonable assumptions are made regarding the mechanism of reflection, it is not necessary to investigate variations in albedo with azimuthal angle of refiection. Once differential dose albedo has been determined for a complete set of incident and reflected polar angles with zero azimuth, albedo at any azimuth can be derived by a suitable transformation. (auth)

  1. Determination of doses to different organs and prediction of health detriment, after hypothetical accident in mtr reactor core

    Energy Technology Data Exchange (ETDEWEB)

    Amin, E A; Abd El-Ghani, A H [National Center of Nuclear Safety and Radiation Control Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    As a result of pypothetical accidents with release of high amount of fission products, the doses to different organs consequent upon inhalation of radioactive fission products are calculated. The processes are modeled using the ORIGIN and TIRION-4 codes: source term, containment and activity enclosure, time dependent activity behaviour in the building, and radiation exposure in the reactor building. Prediction of health detriments were calculated using ICRP-60 nominal probability coefficients and organ doses determined for bone, lung, and thyroid gland, after whole body exposure from internal inhalation and external emmersion. 11 tabs.

  2. Determining and managing fetal radiation dose from diagnostic radiology procedures in Turkey

    International Nuclear Information System (INIS)

    Ozbayrak, Mustafa; Cavdar, Iffet; Seven, Mehmet; Uslu, Lebriz; Yeyin, Nami; Tanyildizi, Handan; Abuqbeitah, Mohammad; Acikgoz, A. Serdar; Tuten, Abdullah; Demir, Mustafa

    2015-01-01

    We intended to calculate approximate fetal doses in pregnant women who underwent diagnostic radiology procedures and to evaluate the safety of their pregnancies. We contacted hospitals in different cities in Turkey where requests for fetal dose calculation are usually sent. Fetal radiation exposure was calculated for 304 cases in 218 pregnant women with gestational ages ranging from 5 days to 19 weeks, 2 days. FetDose software (ver. 4.0) was used in fetal dose calculations for radiographic and computed tomography (CT) procedures. The body was divided into three zones according to distance from the fetus. The first zone consisted of the head area, the lower extremities below the knee, and the upper extremities; the second consisted of the cervicothoracic region and upper thighs; and the third consisted of the abdominopelvic area. Fetal doses from radiologic procedures between zones were compared using the Kruskal-Wallis test and a Bonferroni-corrected Mann-Whitney U-test. The average fetal doses from radiography and CT in the first zone were 0.05 ± 0.01 mGy and 0.81 ± 0.04 mGy, respectively; 0.21 ± 0.05 mGy and 1.77 ± 0.22 mGy, respectively, in the second zone; and 6.42 ± 0.82 mGy and 22.94 ± 1.28 mGy, respectively, in the third zone (p < 0.001). Our results showed that fetal radiation exposures in our group of pregnant women did not reach the level (50 mGy) that is known to increase risk for congenital anomalies. Fetal radiation exposure in the diagnostic radiology procedures in our study did not reach risk levels that might have indicated abortion

  3. Determination of dose rate from natural radionuclide in porcelain dental materials

    International Nuclear Information System (INIS)

    Nouri, A.D.; El-Zourgany, A.; Elmashat, Alia; El-Masri, Karima

    2010-01-01

    There are three main aims that make this study particularly important and interesting to radiometric studies. Firstly, it will provides information on the concentration composition of natural and the associated man-made radioactivity of imported dental porcelain materials to be used by most dental laboratories in Great Jamahiriya. Since these materials do not pass radiation inspection tests before their entry or use and there is a large variety of supply source of these dental materials to be used for all dental works on Libyan patients, anomalies can be identified easily. Secondly, the analysis of selective elemental abundance (U, Th, and K ) and dose rate calculations may be used to calculate effective dose rates to dental laboratory technicians and also to the patient who will be using these specific materials. This research project will provide the first results of such measurements and the corresponding average annual effective dose rates equivalent to the patients using these materials and also to the dental technician and doctors work in the various dental laboratories that make use of these materials in their daily work. A total number of 30 dental powder samples were collected from a number of dental laboratories around Tripoli area will be analyzed. In this research project, the results from this preliminary survey regarding Th, U and K elemental concentrations in a wide variety of dental materials by means of high-resolution X-ray spectrometry will be presented. Further results from these investigations concerning activity concentrations and the associated dose rates, effective dose and the committed dose due to the use of these materials are going to be calculated and compared with other published data elsewhere and recommendation of their use will be derived accordingly. (author)

  4. Determining and managing fetal radiation dose from diagnostic radiology procedures in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Ozbayrak, Mustafa; Cavdar, Iffet; Seven, Mehmet; Uslu, Lebriz; Yeyin, Nami; Tanyildizi, Handan; Abuqbeitah, Mohammad; Acikgoz, A. Serdar; Tuten, Abdullah; Demir, Mustafa [Istanbul University, Istanbul (Turkmenistan)

    2015-12-15

    We intended to calculate approximate fetal doses in pregnant women who underwent diagnostic radiology procedures and to evaluate the safety of their pregnancies. We contacted hospitals in different cities in Turkey where requests for fetal dose calculation are usually sent. Fetal radiation exposure was calculated for 304 cases in 218 pregnant women with gestational ages ranging from 5 days to 19 weeks, 2 days. FetDose software (ver. 4.0) was used in fetal dose calculations for radiographic and computed tomography (CT) procedures. The body was divided into three zones according to distance from the fetus. The first zone consisted of the head area, the lower extremities below the knee, and the upper extremities; the second consisted of the cervicothoracic region and upper thighs; and the third consisted of the abdominopelvic area. Fetal doses from radiologic procedures between zones were compared using the Kruskal-Wallis test and a Bonferroni-corrected Mann-Whitney U-test. The average fetal doses from radiography and CT in the first zone were 0.05 ± 0.01 mGy and 0.81 ± 0.04 mGy, respectively; 0.21 ± 0.05 mGy and 1.77 ± 0.22 mGy, respectively, in the second zone; and 6.42 ± 0.82 mGy and 22.94 ± 1.28 mGy, respectively, in the third zone (p < 0.001). Our results showed that fetal radiation exposures in our group of pregnant women did not reach the level (50 mGy) that is known to increase risk for congenital anomalies. Fetal radiation exposure in the diagnostic radiology procedures in our study did not reach risk levels that might have indicated abortion.

  5. Radiobiological Determination of Dose Escalation and Normal Tissue Toxicity in Definitive Chemoradiation Therapy for Esophageal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Samantha, E-mail: Samantha.warren@oncology.ox.ac.uk [Department of Oncology, Gray Institute of Radiation Oncology and Biology, University of Oxford, Oxford (United Kingdom); Partridge, Mike [Department of Oncology, Gray Institute of Radiation Oncology and Biology, University of Oxford, Oxford (United Kingdom); Carrington, Rhys [Velindre Cancer Centre, Velindre Hospital, Cardiff (United Kingdom); Hurt, Chris [Wales Cancer Trials Unit, School of Medicine, Heath Park, Cardiff (United Kingdom); Crosby, Thomas [Velindre Cancer Centre, Velindre Hospital, Cardiff (United Kingdom); Hawkins, Maria A. [Department of Oncology, Gray Institute of Radiation Oncology and Biology, University of Oxford, Oxford (United Kingdom)

    2014-10-01

    Purpose: This study investigated the trade-off in tumor coverage and organ-at-risk sparing when applying dose escalation for concurrent chemoradiation therapy (CRT) of mid-esophageal cancer, using radiobiological modeling to estimate local control and normal tissue toxicity. Methods and Materials: Twenty-one patients with mid-esophageal cancer were selected from the SCOPE1 database (International Standard Randomised Controlled Trials number 47718479), with a mean planning target volume (PTV) of 327 cm{sup 3}. A boost volume, PTV2 (GTV + 0.5 cm margin), was created. Radiobiological modeling of tumor control probability (TCP) estimated the dose required for a clinically significant (+20%) increase in local control as 62.5 Gy/25 fractions. A RapidArc (RA) plan with a simultaneously integrated boost (SIB) to PTV2 (RA{sub 62.5}) was compared to a standard dose plan of 50 Gy/25 fractions (RA{sub 50}). Dose-volume metrics and estimates of normal tissue complication probability (NTCP) for heart and lungs were compared. Results: Clinically acceptable dose escalation was feasible for 16 of 21 patients, with significant gains (>18%) in tumor control from 38.2% (RA{sub 50}) to 56.3% (RA{sub 62.5}), and only a small increase in predicted toxicity: median heart NTCP 4.4% (RA{sub 50}) versus 5.6% (RA{sub 62.5}) P<.001 and median lung NTCP 6.5% (RA{sub 50}) versus 7.5% (RA{sub 62.5}) P<.001. Conclusions: Dose escalation to the GTV to improve local control is possible when overlap between PTV and organ-at-risk (<8% heart volume and <2.5% lung volume overlap for this study) generates only negligible increase in lung or heart toxicity. These predictions from radiobiological modeling should be tested in future clinical trials.

  6. Determination of dose rates in beta radiation fields using extrapolation chamber and GM counter

    DEFF Research Database (Denmark)

    Borg, J.; Christensen, P.

    1995-01-01

    of depth-dose profiles from different beta radiation fields with E(max) values down to 156 keV. Results are also presented from studies of GM counters for use as survey instruments for monitoring beta dose rates at the workplace. Advantages of GM counters are a simple measurement technique and high...... sensitivity. GM responses were measured from exposures in different beta radiation fields using different filters in front of the GM detector and the paper discusses the possibility of using the results from GM measurements with two different filters in an unknown beta radiation field to obtain a value...

  7. The 1997 determination of the Australian standards of exposure and absorbed dose at 60Co

    International Nuclear Information System (INIS)

    Huntley, R.B.; Boas, J.F.; Van der Gaast, H.

    1998-05-01

    The arrangements for the maintenance of the Australian standards for 60 Co are described in detail. The primary standards are a graphite cavity chamber for exposure/air kerma and a graphite calorimeter for absorbed dose. These secondary standards are described and their responses in corresponding 90 Sr reference sources are reported. Accurate ratios between the Australian Radiation Laboratory (ARL) and Australian Nuclear Science and Technology (ANSTO) 90 Sr reference sources are derived for use in future calibrations. The value of 28.8 years for the half-life of 90 Sr is confirmed. The usefulness of 90 Sr reference source measurements in quality assurance is discussed. The charge sensitivity and linearity of the ANSTO electrometers are reported by two different methods and are compared with previous results. Calibration factors for all the secondary standard ionization chambers are given, in terms of exposure, air kerma and absorbed dose to water. Calibration factors are also given for most of the chambers in terms of absorbed dose to graphite. The methods of deriving the calibration factors are explained in detail, including all the corrections applied to both the primary and secondary standard measurements. Three alternative methods of deriving the absorbed dose to water calibration factors are compared. The reported calibration factors are compared with previous results. Changes in the Australian units of exposure, air kerma and absorbed dose to graphite and water are derived from changes in the corresponding calibration factors. The Australian units of exposure and air kerma have not changed significantly since 1990. The Australian unit of absorbed dose to graphite is now 1.1 % smaller than in 1993 and 1.3 % smaller than in 1990. The Australian unit of absorbed dose to water is now 1.4 % smaller than in 1993, but is only 0.9 % smaller than in 1990. Comparisons of the Australian standards of exposure/air kerma and absorbed dose with those of the Bureau

  8. The 1997 determination of the Australian standards of exposure and absorbed dose at {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Huntley, R.B.; Boas, J.F. [Australian Radiation Laboratory, Yallambie, VIC (Australia); Van der Gaast, H. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1998-05-01

    The arrangements for the maintenance of the Australian standards for {sup 60}Co are described in detail. The primary standards are a graphite cavity chamber for exposure/air kerma and a graphite calorimeter for absorbed dose. These secondary standards are described and their responses in corresponding {sup 90}Sr reference sources are reported. Accurate ratios between the Australian Radiation Laboratory (ARL) and Australian Nuclear Science and Technology (ANSTO) {sup 90}Sr reference sources are derived for use in future calibrations. The value of 28.8 years for the half-life of {sup 90}Sr is confirmed. The usefulness of {sup 90}Sr reference source measurements in quality assurance is discussed. The charge sensitivity and linearity of the ANSTO electrometers are reported by two different methods and are compared with previous results. Calibration factors for all the secondary standard ionization chambers are given, in terms of exposure, air kerma and absorbed dose to water. Calibration factors are also given for most of the chambers in terms of absorbed dose to graphite. The methods of deriving the calibration factors are explained in detail, including all the corrections applied to both the primary and secondary standard measurements. Three alternative methods of deriving the absorbed dose to water calibration factors are compared. The reported calibration factors are compared with previous results. Changes in the Australian units of exposure, air kerma and absorbed dose to graphite and water are derived from changes in the corresponding calibration factors. The Australian units of exposure and air kerma have not changed significantly since 1990. The Australian unit of absorbed dose to graphite is now 1.1 % smaller than in 1993 and 1.3 % smaller than in 1990. The Australian unit of absorbed dose to water is now 1.4 % smaller than in 1993, but is only 0.9 % smaller than in 1990. Comparisons of the Australian standards of exposure/air kerma and absorbed dose with

  9. Determination of the dose rapidity of a 90 Sr beta radiation source using thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Gonzalez M, P.R.; Azorin N, J.; Rivera M, T.

    2000-01-01

    The thermoluminescent dosemeters developed in Mexico, have been used efficiently in environmental and personal dosimetry. When the dose rate of some source is not known can be estimated with the use of thermoluminescent dosemeters taking in account the geometrical array used in the irradiations for reproducibility of the results in posterior irradiations. In this work it was estimated the dose rate of a 90 Sr- 90 Y beta radiation source which is property of the Nuclear Sciences Institute, UNAM, therefore it was l ended to the Metropolitan Autonomous University- Iztapalapa Unit for the characterization of new Tl materials, taking account of the institutional collaboration agreements. (Author)

  10. The meaning and the principle of determination of the effective dose equivalent in radiation protection

    International Nuclear Information System (INIS)

    Drexler, G.; Williams, G.; Zankl, M.

    1985-01-01

    Since the introduction of the quantity ''effective dose equivalent'' within the framework of new radiation concepts, the meaning and interpretation of the quantity is often discussed and debated. Because of its adoption as a limiting quantity in many international and national laws, it is necessary to be able to interpret this main radiation protection quantity. Examples of organ doses and the related Hsub(E) values in occupational and medical exposures are presented and the meaning of the quantity is considered for whole body exposures to external and internal photon sources, as well as for partial body external exposures to photons. (author)

  11. Educational ultrasound nondestructive testing laboratory.

    Science.gov (United States)

    Genis, Vladimir; Zagorski, Michael

    2008-09-01

    The ultrasound nondestructive evaluation (NDE) of materials course was developed for applied engineering technology students at Drexel University's Goodwin College of Professional Studies. This three-credit, hands-on laboratory course consists of two parts: the first part with an emphasis on the foundations of NDE, and the second part during which ultrasound NDE techniques are utilized in the evaluation of parts and materials. NDE applications are presented and applied through real-life problems, including calibration and use of the latest ultrasonic testing instrumentation. The students learn engineering and physical principles of measurements of sound velocity in different materials, attenuation coefficients, material thickness, and location and dimensions of discontinuities in various materials, such as holes, cracks, and flaws. The work in the laboratory enhances the fundamentals taught during classroom sessions. This course will ultimately result in improvements in the educational process ["The greater expectations," national panel report, http://www.greaterexpectations.org (last viewed February, 2008); R. M. Felder and R. Brent "The intellectual development of Science and Engineering Students. Part 2: Teaching to promote growth," J. Eng. Educ. 93, 279-291 (2004)] since industry is becoming increasingly reliant on the effective application of NDE technology and the demand on NDE specialists is increasing. NDE curriculum was designed to fulfill levels I and II NDE in theory and training requirements, according to American Society for Nondestructive Testing, OH, Recommended Practice No. SNT-TC-1A (2006).

  12. Method for determining the irradiation dose deposited in a scintillator by ionising radiation and associated device - WO 2013060745 A1

    International Nuclear Information System (INIS)

    2013-01-01

    The invention relates to a method for determining an irradiation dose deposited in a scintillator (5) by ionising radiation, said method comprising the steps of: irradiating the scintillator (5) for a pre-determined time; detecting an instant at which the scintillator (5) is excited, using a first photodetector (11); subsequently, detecting an instant at which a scintillation photon is received, using a second photodetector (14) operating in single photon counting mode; identifying each sequence formed by the detection of an excitation instant by the first photodetector (11) and the detection of a reception instant by the second photodetector (14) at a coincidence event; counting the number of coincidence events; and obtaining the irradiation dose deposited during the irradiation time as a function of the number of coincidence events counted and a pre-determined proportionality factor. (authors)

  13. Automation of testing the metrological reliability of nondestructive control systems

    International Nuclear Information System (INIS)

    Zhukov, Yu.A.; Isakov, V.B.; Karlov, Yu.K.; Kovalevskij, Yu.A.

    1987-01-01

    Opportunities of microcomputers are used to solve the problem of testing control-measuring systems. Besides the main program the program of data processing when characterizing the nondestructive control systems is written in the microcomputer. The program includes two modules. The first module contains tests-programs, by which accuracy of functional elements of the microcomputer and interface elements with issuing a message to the operator on readiness of the elements for operation and failure of a certain element are determined. The second module includes: calculational programs when determining metrological reliability of measuring channel reliability, a calculational subprogram for random statistical measuring error, time instability and ''dead time''. Automation of testing metrological reliability of the nondestructive control systems increases reliability of determining metrological parameters and reduces time of system testing

  14. A robust method for determining the absorbed dose to water in a phantom for low-energy photon radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, T, E-mail: thorsten.schneider@ptb.de [Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig (Germany)

    2011-06-07

    The application of more and more low-energy photon radiation in brachytherapy-either in the form of low-dose-rate radioactive seeds such as Pd-103 or I-125 or in the form of miniature x-ray tubes-has induced greater interest in determining the absorbed dose to water in water in this energy range. As it seems to be hardly feasible to measure the absorbed dose with calorimetric methods in this low energy range, ionometric methods are the preferred choice. However, the determination of the absorbed dose to water in water by ionometric methods is difficult in this energy range. With decreasing energy, the relative uncertainty of the photon cross sections increases and as the mass energy transfer coefficients show a steep gradient, the spectra of the radiation field must be known precisely. In this work two ionometric methods to determine the absorbed dose to water are evaluated with respect to their sensitivity to the uncertainties of the spectra and of the atomic database. The first is the measurement of the air kerma free in air and the application of an MC-based conversion factor to the absorbed dose to water. The second is the determination of the absorbed dose to water by means of an extrapolation chamber as an integral part of a phantom. In the complementing MC-calculations, two assortments of spectra each of which is based on a separate unfolding procedure were used as well as two kinds of databases: the standard PEGS and the recently implemented NIST database of EGSnrc. Experimental results were obtained by using a parallel-plate graphite extrapolation chamber and a free-air chamber. In the case when the water kerma in a phantom is determined from the measurements of air kerma free in air, differences in the order of 10% were found, according to which the database or the kind of spectrum is used. In contrast to this, for the second method, the differences found were about 0.5%.

  15. The determination of the space distribution, energy spectrum and dose parameters of thermal column beam resulting from swimming pool reactor

    International Nuclear Information System (INIS)

    Chen Changmao; Xie Jianlun; Leng Ruiping; Song Shushou; Su Jingling

    1991-01-01

    The axial and radial distribution, epithermal energy spectrum and dose equivalent rate of thermal column beam resulting from SPR have been determined in the Institute of Atomic Energy. The results show that the neutron fluence rate along the axial direction decreases as the distance increases outside the thermal column channel, and the trend of fluence rate attenuation follows approximately the inverse square law of a point source. When the reactor thermal power rate is 3 MW, at a distance of 50 cm to the channel, the thermal and epithermal neutron fluence rate are about 1.61 x 10 7 and 6.1 x 10 4 n/cm 2 · s respectively; dose equivalent rates are some 62 and 2.9 cSv/h respectively. At the end of the chennal, γ dose equivalent rate is 60 cSv/h or so

  16. Determination of entrance skin dose from diagnostic X-ray of human ...

    African Journals Online (AJOL)

    patient during x-ray examination in Federal Medical Centre, Keffi in Nasarawa state, Nigeria. Entrance skin doses (ESDs) for a common type of x-ray procedures, namely chest AP/PA (anterior/posterior) were measured. A total of 200 data were collected from patients who were exposed to diagnostic X-ray during their routine ...

  17. Which genetic determinants should be considered for tacrolimus dose optimization in kidney transplantation?

    DEFF Research Database (Denmark)

    Bruckmueller, H; Werk, Anneke Nina; Renders, Lutz

    2014-01-01

    ). In addition, there are further polymorphic genes, possibly influencing CYP3A activity (pregnan x receptor NR1I2, P450 oxidoreductase POR and peroxisome proliferator-activator receptor alpha PPRA). We aimed to investigate combined effects of these gene variants on tacrolimus maintenance dose and PK in stable...

  18. Granulometric determinations and inhalation dose assessment for atmospheric aerosol contaminated by 137Cs

    International Nuclear Information System (INIS)

    Castellani, C.M.; Luciani, A.; Oliviero, L.; Donato, R.

    1996-07-01

    During the redevelopment of Brescia freight-yard a measurement campaign of atmospheric aerosol was carried out: in fact a 137 Cs ground contamination, caused by the permanence of wagons carrying iron materials contaminated by this radionuclide, had been found out. During the redevelopment phases of excavation and can filling the workers were exposed to the danger of radioactive aerosol inhalation. The aim of the measurement campaign was to test the aerosol sampling and granulometric analysis methodologies with their sensitivity related to the inhalation dose assessments. The results of both aerosuspended mass and activity, evaluated by means of a portable cascade impactor, are presented. The granulometries have been interpolated with a log normal distribution using an iterative routine minimizing the square deviation between the calculated and experimental data. The results related to the dose assessments are also presented. These evaluations have been carried out using both the granulometric information obtained and the more recent models (ICRP 66) both the total concentration data and the dose coefficients referring to the standard conditions of ICRP 68 and of the Italian law (D.Lgs. 230/95). Furthermore the significance and the reliability of the dose assessments referring to the different methodologies are discussed, also in relation to the possibility of using this sampling methodologies for other radionuclides and different exposure conditions

  19. Dose determination in radiotherapy for photon beams modified by static intensity modulators

    International Nuclear Information System (INIS)

    Castellanos Lopez, M.E.

    1998-01-01

    The static intensity modulators, used in radiotherapy, modify the spectral composition of the beam and lead to specific problems of the dose calculation. The aim of this work was to establish a three dimensional calculation, global and accurate, adapted to the primary-diffused separation algorithm and valid for any static modulator type. A theoretical study, experimentally verified, allowed the evaluation of the primary fluence, resulting from metallic sheets placed between photons beams of 6 to 23 MV nominal energy. It has been showed that the diffused, coming from the modulators, could be neglected for weak thickness and for the relative dose variation. In return it leads to significant variations of many % on the absolute dose and must be take into account for the bigger thicknesses. Corrective methods for the primary fluence have been proposed. From the energy spectra of the beam, the metallic modulator influence has been studied on the primary and diffused components of the dose and improvements of the calculation method have been proposed. These improvements are based on the modulator representation as a transmission matrix and on semi-empirical corrective factors. (A.L.B.)

  20. Determination of 210Po concentration in commercially available infant formulae and assessment of daily ingestion dose

    Directory of Open Access Journals (Sweden)

    Ravi K. Prabhath

    2015-07-01

    Full Text Available A study has been conducted to estimate the concentration of natural radioactive polonium in commercially available packaged infant food formulae available in Mumbai, India and the corresponding daily dose normalized based on its shelf life. Eleven most popular international brands of infant formulae were sourced from market and three aliquots from each sample were analysed for concordant results. Autodeposition method onto a silver planchet from hot dilute acid solution followed by alpha spectrometry was performed for estimation of polonium. Radiochemical recovery was ascertained by the addition of 209Po tracer. Radiochemical recovery of 209Po tracer was ranged from 14.7 to 98.1 %. The 210Po concentration in the samples was in the range of 0.08–0.23 Bq kg−1 on measured date and the corresponding daily dose, calculated on normalized date which is at mid-point of the shelf life of the sample, was ranged from 0.04 to 0.89 μSv d−1 as per the recommended daily consumption. The annual committed effective dose estimated based on the average of daily dose was found to be 150 μSv.

  1. Accuracy determination of dose calibrators in Nuclear Medicine Centers using Tl-201

    International Nuclear Information System (INIS)

    Sattari, A.; Feizi, H.; Ghafoori, M.

    2008-01-01

    Full text: Correct administrated activity of radiopharmaceuticals is an important factor to ensure that administrated radiopharmaceutical is accurately measured and to avoid unnecessary exposure to patients. In this article, nuclear medicine group and Secondary Standard Dosimetry Laboratory (SSDL), has introduced a comparison study with 201 Tl to check the accuracy of dose calibrators in some nuclear medicine centers. First, the dose calibrator in cyclotron department was calibrated by SSDL using 133 Ba, 57 Co, 137 Cs and standard Europium sources. Then, 2ml produced 201 Tl solution containing 16±0.1 mCi was accurately sub-divided into a series of 10 ml Schott vials and delivered to 12 nuclear medicine centers that have been participated in this study. Participants were requested to assay their Schott vials in their dose calibrators at the same time and report the result on the especial sheet. Difference between the activities values reported by participants (A p ) with assayed activity on cyclotron department (Ac), defined as error value. In comparison of A c with A p , 10 centers (83%) has positive and 2 others (17%) has negative error. The range of positive error 2.6% -17.9% and range of negative error 5%-8.5%, by the average of 8.67 and %SD = 7.39 have been calculated. In conclusion, although nuclear medicine centers do calibration on their dose calibrators but establishment a regular audit system seems to be necessary. (author)

  2. Non-invasive determination of the irradiation dose in fingers using low-frequency EPR

    International Nuclear Information System (INIS)

    Zdravkova, M; Crokart, N; Trompier, F; Beghein, N; Gallez, B; Debuyst, R

    2004-01-01

    Several reports in the literature have described the effects of radiation in workers who exposed their fingers to intense radioactive sources. The radiation injuries occurring after local exposure to a high dose (20 to 100 Gy) could lead to the need for amputation. Follow-up of victims needs to be more rational with a precise knowledge of the irradiated area that risks tissue degradation and necrosis. It has been described previously that X-band electron paramagnetic resonance (EPR) spectroscopy could be used to assess the dose in irradiated amputated fingers. Here, we propose the use of low-frequency EPR spectroscopy to evaluate non-invasively the absorbed dose. Low-frequency microwaves are indeed less absorbed by water and penetrate more deeply into living material (∼10 mm in tissues using 1 GHz spectrometers). This work presents preliminary results obtained with baboon and human fingers compared with human dry phalanxes placed inside a surface-coil resonator. The EPR signal increased linearly with the dose. The ratio of the slopes of the dry bone to whole finger linear regression lines was around 5. The detection limit achievable with the present spectrometer and resonator is around 60 Gy, which is well within the range of accidentally exposed fingers. It is likely that the detection limit could be improved in the future, thanks to further technical spectrometer and resonator developments as well as to appropriate spectrum deconvolution into native and dosimetric signals

  3. Determinants of personal ultraviolet-radiation exposure doses on a sun holiday

    DEFF Research Database (Denmark)

    Petersen, B; Thieden, E; Philipsen, P A

    2013-01-01

    A great number of journeys to sunny destinations are sold to the Danish population every year. We suspect that this travel considerably increases personal annual ultraviolet-radiation (UVR) exposure doses. This is important because such exposure is the main cause of skin cancer, and studies have...

  4. Active spectral imaging nondestructive evaluation (SINDE) camera

    Energy Technology Data Exchange (ETDEWEB)

    Simova, E.; Rochefort, P.A., E-mail: eli.simova@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2016-06-15

    A proof-of-concept video camera for active spectral imaging nondestructive evaluation has been demonstrated. An active multispectral imaging technique has been implemented in the visible and near infrared by using light emitting diodes with wavelengths spanning from 400 to 970 nm. This shows how the camera can be used in nondestructive evaluation to inspect surfaces and spectrally identify materials and corrosion. (author)

  5. Non-destructive testing at Chalk River

    International Nuclear Information System (INIS)

    Hilborn, J.W.

    1976-01-01

    In 1969 CRNL recognized the need for a strong group skilled in non-destructive test procedures. Within two years a new branch called Quality Control Branch was staffed and working. This branch engages in all aspects of non-destructive testing including development of new techniques, new applications of known technology, and special problems in support of operating reactors. (author)

  6. The significance of 1-131 scan dose in patients with thyroid cancer: determination of ablation: concise communication

    International Nuclear Information System (INIS)

    Waxman, A.; Ramanna, L.; Chapman, N.; Chapman, D.; Brachman, M.; Tanasescu, D.; Berman, D.; Catz, B.; Braunstein, G.

    1981-01-01

    Twenty-four patients with differentiated thyroid cancer were studied with diagnostic I-131 neck chest scans after having undergone bilateral subtotal thyroidectomy and initial I-131 therapy with either 30- or 100-mCi doses. With an endogenous stimulation protocol, follow-up studies were performed with neck and chest scans using 2 and 10 mCi I-131. A 400% increase in sensitivity was found with a 10-mCi dose relative to a 2-mCi dose. Comparison with therapeutic doses of 30 and 100 mCi resulted in further increases in the detection of residual iodine-avid tissue. We conclude that a 2-mCi or lower dose of I-131 is inadequate in evaluating residual iodine-avid tissue visually in patients with thyroid cancer. The study does not answer the critical question of whether it is necessary to treat a patient presenting a negative 2-mCi but a positive 10-mCi scan. It may be appropriate to define ablation visually as well as clinically, with further studies directed toward determining a treatment rationale in this patient population

  7. Determination of dose levels for chest (PA), lumbar spine (AP and LAT) and mammography (CC and MLO) for Latin america

    International Nuclear Information System (INIS)

    Mora, P.; Ramirez, R.; Blanco, D. E.; Benavente, T. A.; Ortiz Lopez, P.; Giannone, C. A.; Gherco, J. T.; Mecca, F.; Kodlulovich, S.; Ramirez, A.; Anselmo Puerta, J. A.; Fonseca, L.; Cardenas, J.; Martinez, A.; Zorin, F. J.; Roas, N.; Garcia, F.; Caldeira, M. E.; Salazar, G.

    2006-01-01

    Under the auspices of the ARCAL Technical Cooperation Program of the IAEA, 11 countries in Latin American (Argentina, Brazil, Chile, Costa Rica, Cuba, Mexico, Nicaragua, Peru, Uruguay and Venezuela) motivated by the necessity to optimize the doses in diagnostic procedures, started the first regional pilot study to determine the guidance dose levels for chest (PA), lumbar spine (AP and LAT) and mammography (CC and MLO) procedures. A total of 33 hospitals participated with 54 diagnostic X-ray equipment and 18 mammography units. The entrance kerma and mean glandular doses were obtained through the output of the X-rays. A TLD intercomparison was carried out as a means to do quality control of all the process. A total of 2120 doses were estimated with the information of each patient (kVp, mAs, distance, etc.). Parallel to this, the image quality of the studies was evaluated using the criteria established by the European Community. The values of the entrance kerma an mean glandular doses for the 75% percentile are in general very compatible with the ones in Schedule III of the NBS. Although this study did not allow the establishment of guidance levels for the region, it did lay the foundations for optimization processes and the necessity of making better efforts that will improve medical practices. (Author)

  8. Accuracy, reproducibility, and uncertainty analysis of thyroid-probe-based activity measurements for determination of dose calibrator settings.

    Science.gov (United States)

    Esquinas, Pedro L; Tanguay, Jesse; Gonzalez, Marjorie; Vuckovic, Milan; Rodríguez-Rodríguez, Cristina; Häfeli, Urs O; Celler, Anna

    2016-12-01

    In the nuclear medicine department, the activity of radiopharmaceuticals is measured using dose calibrators (DCs) prior to patient injection. The DC consists of an ionization chamber that measures current generated by ionizing radiation (emitted from the radiotracer). In order to obtain an activity reading, the current is converted into units of activity by applying an appropriate calibration factor (also referred to as DC dial setting). Accurate determination of DC dial settings is crucial to ensure that patients receive the appropriate dose in diagnostic scans or radionuclide therapies. The goals of this study were (1) to describe a practical method to experimentally determine dose calibrator settings using a thyroid-probe (TP) and (2) to investigate the accuracy, reproducibility, and uncertainties of the method. As an illustration, the TP method was applied to determine 188 Re dial settings for two dose calibrator models: Atomlab 100plus and Capintec CRC-55tR. Using the TP to determine dose calibrator settings involved three measurements. First, the energy-dependent efficiency of the TP was determined from energy spectra measurements of two calibration sources ( 152 Eu and 22 Na). Second, the gamma emissions from the investigated isotope ( 188 Re) were measured using the TP and its activity was determined using γ-ray spectroscopy methods. Ambient background, scatter, and source-geometry corrections were applied during the efficiency and activity determination steps. Third, the TP-based 188 Re activity was used to determine the dose calibrator settings following the calibration curve method [B. E. Zimmerman et al., J. Nucl. Med. 40, 1508-1516 (1999)]. The interobserver reproducibility of TP measurements was determined by the coefficient of variation (COV) and uncertainties associated to each step of the measuring process were estimated. The accuracy of activity measurements using the proposed method was evaluated by comparing the TP activity estimates of 99m Tc

  9. Decimal reduction dose (D10) and optimal dose determination to eliminate salmonella typhimurium in chicken hamburgers through 60Co gamma radiation

    International Nuclear Information System (INIS)

    Basurto B, H.M.

    2001-01-01

    Under aerobic conditions and at room temperature, decimal reduction dose (D 10 ) of S. typhimurium in casoy broth (TSB) was determined through irradiation, inoculating 9,78 log ufc/mL of a strain during 24±2 hours and obtaining a D 10 of 0,425 kGy. Next, the D 10 value of S. typhimurium inoculated in chicken hamburger with a 9,3 log ufc/g concentration was determined under the same conditions of the previous case, obtaining a D 10 of 0,547 kGy, 22,3% higher than the first value. Then, hamburgers were irradiated at 2, 4 and 6 kGy and kept under storage for 57 days at 2±2 o C. During evaluations, it was observed that there is a synergic effect between the irradiation dose and the time of storage (α=5%) for S. typhimurium inoculated in hamburgers. Besides, in the case of the non-irradiated samples, the number of total coliforms increased from 29 to 4250 NMP/g in day 22, while fecal coliforms increased from 4 to 240 NMP/g during the same period, dropping at the end of storage. In the case of irradiated samples, no coliforms were found (<3 NMP/g). Mesofilic and psicrotrofic bacteria diminished their ability to form colonies proportionally to the applied irradiation doses. Nevertheless, as storage time goes by, these bacteria recover the ability to grow up and cause deterioration. Peroxide rate values of irradiated samples were 100% higher than those of the non-irradiated samples. However, there was no significant difference between samples treated at 2,4 and 6 kGy. Finally, useful life of hamburgers was determined through sensorial evaluation of characteristics such as color, external appearance and smell of raw hamburgers, and taste, smell and texture of fried hamburgers. The results obtained were 13, 19, 41 and 34 days for non-irradiated samples, at 2, 4, and 6 kGy respectively

  10. Determination of the optimal dose reduction level via iterative reconstruction using 640-slice volume chest CT in a pig model.

    Directory of Open Access Journals (Sweden)

    Xingli Liu

    Full Text Available To determine the optimal dose reduction level of iterative reconstruction technique for paediatric chest CT in pig models.27 infant pigs underwent 640-slice volume chest CT with 80kVp and different mAs. Automatic exposure control technique was used, and the index of noise was set to SD10 (Group A, routine dose, SD12.5, SD15, SD17.5, SD20 (Groups from B to E to reduce dose respectively. Group A was reconstructed with filtered back projection (FBP, and Groups from B to E were reconstructed using iterative reconstruction (IR. Objective and subjective image quality (IQ among groups were compared to determine an optimal radiation reduction level.The noise and signal-to-noise ratio (SNR in Group D had no significant statistical difference from that in Group A (P = 1.0. The scores of subjective IQ in Group A were not significantly different from those in Group D (P>0.05. There were no obvious statistical differences in the objective and subjective index values among the subgroups (small, medium and large subgroups of Group D. The effective dose (ED of Group D was 58.9% lower than that of Group A (0.20±0.05mSv vs 0.48±0.10mSv, p <0.001.In infant pig chest CT, using iterative reconstruction can provide diagnostic image quality; furthermore, it can reduce the dosage by 58.9%.

  11. Determination of the distal dose edge in a human phantom by measuring the prompt gamma distribution: a Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Min, Chul Hee; Lee, Han Rim; Yeom, Yeon Su; Cho, Sung Koo; Kim, Chan Hyeong [Hanyang University, Seoul (Korea, Republic of)

    2010-06-15

    The close relationship between the proton dose distribution and the distribution of prompt gammas generated by proton-induced nuclear interactions along the path of protons in a water phantom was demonstrated by means of both Monte Carlo simulations and limited experiments. In order to test the clinical applicability of the method for determining the distal dose edge in a human body, a human voxel model, constructed based on a body-composition-approximated physical phantom, was used, after which the MCNPX code was used to analyze the energy spectra and the prompt gamma yields from the major elements composing the human voxel model; finally, the prompt gamma distribution, generated from the voxel model and measured by using an array-type prompt gamma detection system, was calculated and compared with the proton dose distribution. According to the results, effective prompt gammas were produced mainly by oxygen, and the specific energy of the prompt gammas, allowing for selective measurement, was found to be 4.44 MeV. The results also show that the distal dose edge in the human phantom, despite the heterogeneous composition and the complicated shape, can be determined by measuring the prompt gamma distribution with an array-type detection system.

  12. Nondestructive verification and assay systems for spent fuels. Technical appendixes

    International Nuclear Information System (INIS)

    Cobb, D.D.; Phillips, J.R.; Baker, M.P.

    1982-04-01

    Six technical appendixes are presented that provide important supporting technical information for the study of the application of nondestructive measurements to spent-fuel storage. Each appendix addresses a particular technical subject in a reasonably self-contained fashion. Appendix A is a comparison of spent-fuel data predicted by reactor operators with measured data from reprocessors. This comparison indicates a rather high level of uncertainty in previous burnup calculations. Appendix B describes a series of nondestructive measurements at the GE-Morris Operation Spent-Fuel Storage Facility. This series of experiments successfully demonstrated a technique for reproducible positioning of fuel assemblies for nondestructive measurement. The experimental results indicate the importance of measuring the axial and angular burnup profiles of irradiated fuel assemblies for quantitative determination of spent-fuel parameters. Appendix C is a reasonably comprehensive bibliography of reports and symposia papers on spent-fuel nondestructive measurements to April 1981. Appendix D is a compendium of spent-fuel calculations that includes isotope production and depletion calculations using the EPRI-CINDER code, calculations of neutron and gamma-ray source terms, and correlations of these sources with burnup and plutonium content. Appendix E describes the pulsed-neutron technique and its potential application to spent-fuel measurements. Although not yet developed, the technique holds the promise of providing separate measurements of the uranium and plutonium fissile isotopes. Appendix F describes the experimental program and facilities at Los Alamos for the development of spent-fuel nondestructive measurement systems. Measurements are reported showing that the active neutron method is sensitive to the replacement of a single fuel rod with a dummy rod in an unirradiated uranium fuel assembly

  13. Preliminary investigations on the determination of three-dimensional dose distributions using scintillator blocks and optical tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kroll, Florian; Karsch, Leonhard [OncoRay - National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden (Germany); Pawelke, Jörg [OncoRay - National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, P.O. Box 510119, 01314 Dresden (Germany)

    2013-08-15

    Purpose: Clinical QA in teletherapy as well as the characterization of experimental radiation sources for future medical applications requires effective methods for measuring three-dimensional (3D) dose distributions generated in a water-equivalent medium. Current dosimeters based on ionization chambers, diodes, thermoluminescence detectors, radiochromic films, or polymer gels exhibit various drawbacks: High quality 3D dose determination is either very sophisticated and expensive or requires high amounts of effort and time for the preparation or read out. New detectors based on scintillator blocks in combination with optical tomography are studied, since they have the potential to facilitate the desired cost-effective, transportable, and long-term stable dosimetry system that is able to determine 3D dose distributions with high spatial resolution in a short time.Methods: A portable detector prototype was set up based on a plastic scintillator block and four digital cameras. During irradiation the scintillator emits light, which is detected by the fixed cameras. The light distribution is then reconstructed by optical tomography, using maximum-likelihood expectation maximization. The result of the reconstruction approximates the 3D dose distribution. First performance tests of the prototype using laser light were carried out. Irradiation experiments were performed with ionizing radiation, i.e., bremsstrahlung (6 to 21 MV), electrons (6 to 21 MeV), and protons (68 MeV), provided by clinical and research accelerators.Results: Laser experiments show that the current imaging properties differ from the design specifications: The imaging scale of the optical systems is position dependent, ranging from 0.185 mm/pixel to 0.225 mm/pixel. Nevertheless, the developed dosimetry method is proven to be functional for electron and proton beams. Induced radiation doses of 50 mGy or more made 3D dose reconstructions possible. Taking the imaging properties into account, determined

  14. Utilization of ALANPOL dosemeter composed by alanine and polyethylene for determination of doses in industrial effluents

    International Nuclear Information System (INIS)

    Rela, Carolina S.; Sampa, Maria Helena de O.; Napolitano, Celia M.; Pontuschka, Walter M.

    2005-01-01

    A study of traceability and accuracy was performed with the dosimetry system ALANPOL developed by IVHTJ/ Poland that uses alanine as a dosimeter and EPR as the read out system. The dosimeter ALANPOL is a polymer compound that aggregates alanine. The dosimeter has the outside diameter 3 mm, and the length of 25,4 mm (1 inch). In order to use this dosimeter for monitoring the existing real time calorimetry dosimeter system set up in a electron beam waste treatment plant. Electron beam and gamma irradiation experiments with ALANPOL was carried out under demineralized water and industrial effluent. The result show that in the dose range of 1-40 kGy the ALANPOL dosimeter system is suitable underwater monitoring for absorbed dose and can be applied for the evaluation of the on line calorimetry dosimeter system. (author)

  15. Determine the Dose Distribution Using Ultrasound Parameters in MAGIC-f Polymer Gels

    Directory of Open Access Journals (Sweden)

    Hossein Masoumi

    2016-02-01

    Full Text Available In this study, using methacrylic and ascorbic acid in gelatin initiated by copper (MAGIC-f polymer gel after megavoltage energy exposure, the sensitivity of the ultrasound velocity and attenuation coefficient dose-dependent parameters was evaluated. The MAGIC-f polymer gel was irradiated under 1.25 MeV cobalt-60, ranging from 0 to 60 Gy in 2-Gy steps, and received dose uniformity and accuracy of ±2%. After calibration of the ultrasonic systems with a frequency of 500 kHz, the parameters of ultrasound velocity and attenuation coefficient of the irradiated gel samples were measured. According to the dose–response curve, the ability of ultrasonic parameters was evaluated in dose rate readings. Based on a 4-order polynomial curve, fitted on the dose–response parameters of ultrasound velocity and attenuation coefficient and observed at 24 hours after irradiation, ultrasonic parameters had more sensitivity. The sensitivity of the dose–velocity and dose-attenuation coefficient curves was observed as 50 m/s/Gy and 0.06 dB/MHz/Gy over the linear range of 4 to 44 Gy, respectively. The ultrasonic parameters at 5°C, 15°C, and 25°C on the gel dosimeter after 0 to 60 Gy irradiation showed that readings at 25°C have higher sensitivity compared to 15°C and 5°C. Maximum sensitivity time and temperature readings of the MAGIC-f ultrasonic parameters were concluded 24 hours after irradiation and at a temperature of 25°C.

  16. Determination of 210Po concentration in commercially available infant formulae and assessment of daily ingestion dose

    OpenAIRE

    Prabhath, Ravi K.; Sreejith, Sathyapriya R.; Nair, Madhu G.; Rao, D.D.; Pradeepkumar, K.S.

    2015-01-01

    A study has been conducted to estimate the concentration of natural radioactive polonium in commercially available packaged infant food formulae available in Mumbai, India and the corresponding daily dose normalized based on its shelf life. Eleven most popular international brands of infant formulae were sourced from market and three aliquots from each sample were analysed for concordant results. Autodeposition method onto a silver planchet from hot dilute acid solution followed by alpha spec...

  17. Experimental determination of the lateral dose response functions of detectors to be applied in the measurement of narrow photon-beam dose profiles.

    Science.gov (United States)

    Poppinga, D; Meyners, J; Delfs, B; Muru, A; Harder, D; Poppe, B; Looe, H K

    2015-12-21

    This study aims at the experimental determination of the detector-specific 1D lateral dose response function K(x) and of its associated rotational symmetric counterpart K(r) for a set of high-resolution detectors presently used in narrow-beam photon dosimetry. A combination of slit-beam, radiochromic film, and deconvolution techniques served to accomplish this task for four detectors with diameters of their sensitive volumes ranging from 1 to 2.2 mm. The particular aim of the experiment was to examine the existence of significant negative portions of some of these response functions predicted by a recent Monte-Carlo-simulation (Looe et al 2015 Phys. Med. Biol. 60 6585-607). In a 6 MV photon slit beam formed by the Siemens Artiste collimation system and a 0.5 mm wide slit between 10 cm thick lead blocks serving as the tertiary collimator, the true cross-beam dose profile D(x) at 3 cm depth in a large water phantom was measured with radiochromic film EBT3, and the detector-affected cross-beam signal profiles M(x) were recorded with a silicon diode, a synthetic diamond detector, a miniaturized scintillation detector, and a small ionization chamber. For each detector, the deconvolution of the convolution integral M(x)  =  K(x)  ∗  D(x) served to obtain its specific 1D lateral dose response function K(x), and K(r) was calculated from it. Fourier transformations and back transformations were performed using function approximations by weighted sums of Gaussian functions and their analytical transformation. The 1D lateral dose response functions K(x) of the four types of detectors and their associated rotational symmetric counterparts K(r) were obtained. Significant negative curve portions of K(x) and K(r) were observed in the case of the silicon diode and the diamond detector, confirming the Monte-Carlo-based prediction (Looe et al 2015 Phys. Med. Biol. 60 6585-607). They are typical for the perturbation of the secondary electron field by a detector with

  18. Neutron spectrometry and determination of neutron ambient dose equivalents in different LINAC radiotherapy rooms

    International Nuclear Information System (INIS)

    Domingo, C.; Garcia-Fuste, M.J.; Morales, E.; Amgarou, K.; Terron, J.A.; Rosello, J.; Brualla, L.; Nunez, L.; Colmenares, R.; Gomez, F.; Hartmann, G.H.; Sanchez-Doblado, F.; Fernandez, F.

    2010-01-01

    A project has been set up to study the effect on a radiotherapy patient of the neutrons produced around the LINAC accelerator head by photonuclear reactions induced by photons above ∼8 MeV. These neutrons may reach directly the patient, or they may interact with the surrounding materials until they become thermalised, scattering all over the treatment room and affecting the patient as well, contributing to peripheral dose. Spectrometry was performed with a calibrated and validated set of Bonner spheres at a point located at 50 cm from the isocenter, as well as at the place where a digital device for measuring neutrons, based on the upset of SRAM memories induced by thermal neutrons, is located inside the treatment room. Exposures have taken place in six LINAC accelerators with different energies (from 15 to 23 MV) with the aim of relating the spectrometer measurements with the readings of the digital device under various exposure and room geometry conditions. The final purpose of the project is to be able to relate, under any given treatment condition and room geometry, the readings of this digital device to patient neutron effective dose and peripheral dose in organs of interest. This would allow inferring the probability of developing second malignancies as a consequence of the treatment. Results indicate that unit neutron fluence spectra at 50 cm from the isocenter do not depend on accelerator characteristics, while spectra at the place of the digital device are strongly influenced by the treatment room geometry.

  19. Biological monitoring to determine worker dose in a butadiene processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Bechtold, W.E.; Hayes, R.B. [National Cancer Inst., Bethesda, MD (United States)

    1995-12-01

    Butadiene (BD) is a reactive gas used extensively in the rubber industry and is also found in combustion products. Although BD is genotoxic and acts as an animal carcinogen, the evidence for carcinogenicity in humans is limited. Extrapolation from animal studies on BD carcinogenicity to risk in humans has been controversial because of uncertainties regarding relative biologic exposure and related effects in humans vs. experimental animals. To reduce this uncertainty, a study was designed to characterize exposure to BD at a polymer production facility and to relate this exposure to mutational and cytogenetic effects. Biological monitoring was used to better assess the internal dose of BD received by the workers. Measurement of 1,2-dihydroxy-4-(N-acetylcysteinyl) butane (M1) in urine served as the biomarker in this study. M1 has been shown to correlate with area monitoring in previous studies. Most studies that relate exposure to a toxic chemical with its biological effects rely on exposure concentration as the dose metric; however, exposure concentration may or may not reflect the actual internal dose of the chemical.

  20. Determination of the dose around an ovoid for treatments in intracavitary brachytherapy Hdr

    International Nuclear Information System (INIS)

    Rivera M, T.; Velasco V, R. A. E.; Serrano F, A. K.; Azorin N, J.

    2010-09-01

    On this work the results of the dosimetric measurements are presented around an ovoid of 2 cm diameter. The measurements were carried out using a water mannequin, an ovoid, a radiation gamma source of 192 Ir and thermoluminescent dosemeters. The dosimetry was realized in the direction of the rectum and bladder. To know the effect of the shielding of the devices type Manchester in the dose, the thermoluminescent dosemeters were irradiated to a radiation gamma source of 192 Ir contained in the Gamma med Plus equipment. The planning was realized normalizing the calculation to 2.5 cm from the applicator center on the transverse plane (2.5, 0, 0). The results show that the dose distribution for an ovoid without shielding is more uniform in the transversal plane to the source axis. The results were compared with the calculated results by means of the planning system BrachyVision. While the absorbed dose distribution around an ovoid with shielding is completely anisotropic. This anisotropic is due to the shielding. (Author)

  1. Radon level and radon effective dose rate determination in Moroccan dwellings using SSNTDs

    International Nuclear Information System (INIS)

    Oufni, L.; Misdaq, M.A.; Amrane, M.

    2005-01-01

    Inhalation of radon ( 222 Rn) and its daughter product are a major source of natural radiation exposure. The measurement of radon activity in dwelling is assuming ever increasing importance. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. Keeping this in view, the indoor radon activity level and radon effective dose rate were carried out in the dwellings of Beni-Mellal, Khouribgra and Ben Guerir cities, Morocco, using the solid state nuclear track detectors (SSNTD) technique. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the 222 Rn effective dose rate in the studied dwellings ranges from 1.01 to 7.90mSvy -1 . The radon activity in the corresponding dwellings was found to vary from 40 to 532Bqm -3 . The radon activity has not only been found to vary with seasonal changes, but also with the age, the construction mode of houses, the ventilation conditions and with specific sites and geological materials

  2. Experimental determination of the angular dependence factor for the dose equivalent for photons in calibration phantoms of PMMA

    International Nuclear Information System (INIS)

    Lund, E.; Carlsson, C.A.; Pernicka, F.

    1994-01-01

    The conversion coefficients from air kerma to dose equivalent at a depth of 10 mm in both a spherical and a slab phantom of PMMA have been determined for the X ray qualities: 40, 80 and 295 kV, ISO 'narrow' spectra; and for 137 Cs γ rays. The angular dependence factors have been experimentally determined for the same qualities and for different angles between 0 o and 180 o . The absorbed doses have been measured with thermoluminescence LiF dosemeters. The conversion coefficients and the angular dependence factors are generally found to agree well with calculated ones. Some minor discrepancies are found for the angular dependence factors and the 30 x 30 x 15 cm 3 PMMA slab phantom. (Author)

  3. Absorbed dose beam quality factors for cylindrical ion chambers: Experimental determination at 6 and 15 MV photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Caporali, C; Guerra, A S; Laitano, R F; Pimpinella, M [ENEA-Casaccia, Inst. Nazionale di Meterologia delle Radiazioni Ionizzanti, Rome (Italy). Dipt. Ambiente

    1996-08-01

    Ion chambers calibrated in terms of absorbed dose to water need an additional factor conventionally designed by k{sub Q} in order to determine the absorbed dose. The quantity k{sub Q} depends on beam quality and chamber characteristics. Rogers and Andreo provided calculations of the k{sub Q} factors for most commercially available ionization chambers for clinical dosimetry. Experimental determinations of the k{sub Q} factors for a number of cylindrical ion chambers have been made and are compared with the calculated values so far published. Measurements were made at 6 MV and 15 MV clinical photon beams at a point in water phantom where the ion chambers and a Fricke dosimeter were alternatively irradiated. The uncertainty on the experimental k{sub Q} factors resulted about {+-} 0.6%. The theoretical and experimental k{sub Q} values are in fairly good agreement. (author). 12 refs, 3 tabs.

  4. Use of Monte Carlo Simulations to Determine Optimal Carbapenem Dosing in Critically Ill Patients Receiving Prolonged Intermittent Renal Replacement Therapy.

    Science.gov (United States)

    Lewis, Susan J; Kays, Michael B; Mueller, Bruce A

    2016-10-01

    Pharmacokinetic/pharmacodynamic analyses with Monte Carlo simulations (MCSs) can be used to integrate prior information on model parameters into a new renal replacement therapy (RRT) to develop optimal drug dosing when pharmacokinetic trials are not feasible. This study used MCSs to determine initial doripenem, imipenem, meropenem, and ertapenem dosing regimens for critically ill patients receiving prolonged intermittent RRT (PIRRT). Published body weights and pharmacokinetic parameter estimates (nonrenal clearance, free fraction, volume of distribution, extraction coefficients) with variability were used to develop a pharmacokinetic model. MCS of 5000 patients evaluated multiple regimens in 4 different PIRRT effluent/duration combinations (4 L/h × 10 hours or 5 L/h × 8 hours in hemodialysis or hemofiltration) occurring at the beginning or 14-16 hours after drug infusion. The probability of target attainment (PTA) was calculated using ≥40% free serum concentrations above 4 times the minimum inhibitory concentration (MIC) for the first 48 hours. Optimal doses were defined as the smallest daily dose achieving ≥90% PTA in all PIRRT combinations. At the MIC of 2 mg/L for Pseudomonas aeruginosa, optimal doses were doripenem 750 mg every 8 hours, imipenem 1 g every 8 hours or 750 mg every 6 hours, and meropenem 1 g every 12 hours or 1 g pre- and post-PIRRT. Ertapenem 500 mg followed by 500 mg post-PIRRT was optimal at the MIC of 1 mg/L for Streptococcus pneumoniae. Incorporating data from critically ill patients receiving RRT into MCS resulted in markedly different carbapenem dosing regimens in PIRRT from those recommended for conventional RRTs because of the unique drug clearance characteristics of PIRRT. These results warrant clinical validation. © 2016, The American College of Clinical Pharmacology.

  5. Towards a determination of the absorbed dose to water in water for low-energy photon-emitting brachytherapy seeds

    International Nuclear Information System (INIS)

    Schneider, T.; Lange, B.; Selbach, H.J.

    2007-01-01

    An accurate determination of the dose produced by brachytherapy seeds emitting low-energy photons is an important component of the radiotherapeutic process. As yet, the output of these seeds has usually been specified in terms of the air kerma rate. The desired quantity in radiation therapy is, however, the absorbed dose to water inside a water phantom, for which primary standards are not available. For this reason, developments are under way in the Physikalisch - Technische Bundesanstalt to establish a primary standard to determine the absorbed dose to water within a phantom. As a fundamental step towards this aim, a method will be introduced in this publication to determine the water kerma inside a graphite phantom housing an extrapolation chamber. Experimental results will be presented and compared with water kerma values obtained from air kerma measurements in free air and applying a conversion factor to water kerma for the conditions of the experiment. First estimates indicate that the relative uncertainty is of the order of 1% (k 1). (authors)

  6. Determination of internal exposure doses of the personnel of uranium-mining company due to radon isotopes decay products

    International Nuclear Information System (INIS)

    Sevostyanov, V.N.

    2004-01-01

    This work carries out a determination of individual doses of internal exposure of the staff of the uranium-mining company in Kazakhstan due to radon decay products. The company extracts uranium by in-situ leaching. After leaching, uranium is sorbed from a solution in facilities where the staff is located. The state of three uranium mines was analyzed. The dose determination was conducted in tune with the proposed method by using integral alpha-tracking detectors to identify the content of 222 Rn and express appliances to identify the content of radio-active aerosols in air of the working area for determination the equilibrium coefficient. The measurements were performed within one year. The work produced the results in average annual values of radon and thoron decay products activity concentration and variation, equilibrium coefficient variation, and so-called expressive-to-integral value conversion factor. The obtained personnel's individual radiation doses due to radon exposure for this period lie within the range of < 1 mSv/year. (author)

  7. Non-destructive determination of moisture content and micro-fibril angle of wood using a poly-chromatic X-ray beam theoretical and experimental approach; Exploitation d'un rayonnement X poly-energetique pour la determination de la teneur en eau et de l'angle de microfibrilles du bois: approche theorique et experimentale

    Energy Technology Data Exchange (ETDEWEB)

    Baettig, R

    2005-07-15

    Non-destructive determination of moisture content and micro-fibril angle are important stakes for the sciences of the wood because these two parameters influence strongly the macroscopic behavior of the wood. For example, the shrinkage, the mechanical properties, the thermal and acoustic conductivity are dependent on the moisture content and their anisotropic character is largely governed by the micro-fibril angle. We used the light difference between X-ray mass attenuation coefficient for the water and for the wood in transmission. Regrettably, the results show that this difference between X-ray mass attenuation coefficient is insufficient to allow the precise measurement of the moisture content.In spite of this, the coherent scattering shows sensitive effects. So, by using a poly-energetic beam and a spectrometric system, we were able to discriminate between the crystalline constituent (cellulose) of the amorphous constituent (water) in a sample of wet wood, because for a given angle these phases scatter in different energy. Besides, the device created allowed us to study the crystalline phase of the wood. We were able to confront experimental profiles of diffraction with theoretical profiles of diffraction, obtained by means of a rigorous simulation, in the objective to estimate the average micro-fibril angle and its standard deviation. (author)

  8. Method for nondestructive fuel assay of laser fusion targets

    Science.gov (United States)

    Farnum, Eugene H.; Fries, R. Jay

    1976-01-01

    A method for nondestructively determining the deuterium and tritium content of laser fusion targets by counting the x rays produced by the interaction of tritium beta particles with the walls of the microballoons used to contain the deuterium and tritium gas mixture under high pressure. The x rays provide a direct measure of the tritium content and a means for calculating the deuterium content using the initial known D-T ratio and the known deuterium and tritium diffusion rates.

  9. Non-destructive analysis of archaeological bronzes by nuclear techniques

    International Nuclear Information System (INIS)

    Respaldiza, M.A.; Gomez-Tubio, B.M.; Sanchez del Junco, A.; Barranco, F.; Saiz-Jimenez, C.

    1994-01-01

    This paper studies a method for overcoming the difficulty of corroded surfaces by means of nondestructive nuclear methods in the determination of the composition of archaeological bronzes. It consists of the combination of PIXE or XRF information with Gamma Ray Transmission (GRT) data. A wide range applicability of this combined method is established by comparison with profiles of concentrations along the bronzes' patina obtained by SEM-EDAX. (orig.)

  10. Method for nondestructive fuel assay of laser fusion targets

    International Nuclear Information System (INIS)

    Farnum, E.H.; Fries, R.J.

    1976-01-01

    A method is described for nondestructively determining the deuterium and tritium content of laser fusion targets by counting the x rays produced by the interaction of tritium beta particles with the walls of the microballoons used to contain the deuterium and tritium gas mixture under high pressure. The x rays provide a direct measure of the tritium content and a means for calculating the deuterium content using the initial known D-T ratio and the known deuterium and tritium diffusion rates

  11. Nondestructive assay instrument for measurement of plutonium in solutions

    International Nuclear Information System (INIS)

    Shirk, D.G.; Hsue, F.; Li, T.K.; Canada, T.R.

    1979-01-01

    A nondestructive assay (NDA) instrument that measures the 239 Pu content in solutions, using a passive gamma-ray spectroscopy technique, has been developed and installed in the LASL Plutonium Processing Facility. A detailed evaluation of this instrument has been performed. The results show that the instrument can routinely determine 239 Pu concentrations of 1 to 500 g/l with accuracies of 1 to 5% and assay times of 1 to 2 x 10 3 s

  12. Non-destructive determination of ultra-thin GaN cap layer thickness in AlGaN/GaN HEMT structure by angle resolved x-ray photoelectron spectroscopy (ARXPS)

    Science.gov (United States)

    Goyal, Anshu; Yadav, Brajesh S.; Raman, R.; Kapoor, Ashok K.

    2018-02-01

    Angle resolved X-ray photoelectron spectroscopy (ARXPS) and secondary ion mass spectrometry (SIMS) investigations have been carried out to characterize the GaN cap layer in AlGaN/GaN HEMT structure. The paper discusses the qualitative (presence or absence of a cap layer) and quantitative (cap layer thickness) characterization of cap layer in HEMT structure non-destructively using ARXPS measurements in conjunction with the theoretical modeling. Further the relative sensitive factor (RSF=σ/Ga σAl ) for Ga to Al ratio was estimated to be 0.963 and was used in the quantification of GaN cap layer thickness. Our results show that Al/Ga intensity ratio varies with the emission angle in the presence of GaN cap layer and otherwise remains constant. Also, the modeling of this intensity ratio gives its thickness. The finding of ARXPS was also substantiated by SIMS depth profiling studies.

  13. Non-destructive determination of ultra-thin GaN cap layer thickness in AlGaN/GaN HEMT structure by angle resolved x-ray photoelectron spectroscopy (ARXPS

    Directory of Open Access Journals (Sweden)

    Anshu Goyal

    2018-02-01

    Full Text Available Angle resolved X-ray photoelectron spectroscopy (ARXPS and secondary ion mass spectrometry (SIMS investigations have been carried out to characterize the GaN cap layer in AlGaN/GaN HEMT structure. The paper discusses the qualitative (presence or absence of a cap layer and quantitative (cap layer thickness characterization of cap layer in HEMT structure non-destructively using ARXPS measurements in conjunction with the theoretical modeling. Further the relative sensitive factor (RSF=σGaσAl for Ga to Al ratio was estimated to be 0.963 and was used in the quantification of GaN cap layer thickness. Our results show that Al/Ga intensity ratio varies with the emission angle in the presence of GaN cap layer and otherwise remains constant. Also, the modeling of this intensity ratio gives its thickness. The finding of ARXPS was also substantiated by SIMS depth profiling studies.

  14. Characteristics of therapeutic electron beams and their determination from depth dose curves

    Energy Technology Data Exchange (ETDEWEB)

    Novotny, J; Pernicka, F [Ceskoslovenska Akademie Ved, Prague. Ustav Dozimetrie Zareni

    1980-09-01

    The distribution of absorbed dose in the environment irradiated with broad beams of high-energy electrons is analyzed physically and therapeutically. A number of parameters are defined with the aid of which the beams of electrons may be characterized in great detail and compared. The theoretical calculations of individual parameters are compared with the values measured using the Ostron betatron in the central axis of the beam at a distance of 65 cm from the target; the differences found are ascribed to the spectrum of electrons, the scattering of electrons on the homogenizing foils, collimators, monitoring chambers, etc.

  15. Kalman filter analysis of delayed neutron nondestructive assay measurements

    International Nuclear Information System (INIS)

    Aumeier, S. E.

    1998-01-01

    The ability to nondestructively determine the presence and quantity of fissile and fertile nuclei in various matrices is important in several nuclear applications including international and domestics safeguards, radioactive waste characterization and nuclear facility operations. Material irradiation followed by delayed neutron counting is a well known and useful nondestructive assay technique used to determine the fissile-effective content of assay samples. Previous studies have demonstrated the feasibility of using Kalman filters to unfold individual isotopic contributions to delayed neutron measurements resulting from the assay of mixes of uranium and plutonium isotopes. However, the studies in question used simulated measurement data and idealized parameters. We present the results of the Kalman filter analysis of several measurements of U/Pu mixes taken using Argonne National Laboratory's delayed neutron nondestructive assay device. The results demonstrate the use of Kalman filters as a signal processing tool to determine the fissile and fertile isotopic content of an assay sample from the aggregate delayed neutron response following neutron irradiation

  16. Estimation of individual radiation doses determined by the biological dosimetry method at the inhabitants of the Chernobyl region

    International Nuclear Information System (INIS)

    Nikolaevich, L.N.

    1997-01-01

    The results obtained by the method of the chromosome aberration analysis in human peripheral blood lymphocytes are given. Hematologically healthy inhabitants of Vetka and Khoiniki districts in Gomel Region (80 adults and 38 children), as well as persons suffering from hemoblastosis (acute lymphoblastic leukemia, acute myeloblastic leukemia) were examined. 27258 metaphase cells being analysed. Only two-hit aberrations (dicentric and ring chromosomes with fragments and without them), specific disturbances in response to radiation effect, were tested for estimating an individual dose of ionizing radiation. The examined groups of adults and children were formed depending on the value of an individual radiation dose: 0 kGy; from 0 to 1,4 kGy and from 1,5 to 3,0 kGy. 39% of adults took the dose up to 1,5 kGy and about 9% did above 2,0 kGy. The tendency towards increasing the amount of aberrant lymphocytes in peripheral blood is observed in persons who took the dose above 2,0 kGy. Among children 52,6% took the doses from 1,5 to 3,0 kGy. No increase in the level of aberrant cells in comparison with the children from the 'zero group' was observed in those children. Apparently, in some cases slightly reduced radiation doses can be obtained by the data of the chromosome analysis method since with the time elimination of a portion of these cells with unstable chromosome aberrations takes place. Elimination of chromosome aberrations in lymphocytes can be caused by different infectious processes which are accompanied by a pronounced immune response inducing inclusion of lymphocytes with aberrations in mitosis and , as a result, disappearance of unstable mutations. However, together with elimination of old chromosome aberrations new ones, caused by ongoing radiation, emerge in people living in radio contaminated regions and thus, the radiation dose determined by the chromosome analysis method even increases with years that can favour rise in malignant tumors. The radiation dose

  17. Dose measurements and LET-determination in space station MIR during the Russian long term flight RLF

    International Nuclear Information System (INIS)

    Vana, N.; Schoener, N.; Fugger, M.; Akatov, Y.; Shurshakov, V.

    1996-01-01

    For determination of the absorbed dose and the dose equivalent in complex mixed radiation fields, new methods were developed in the frame of the Austrian-Soviet space mission AUSTROMIR in October 1991. The method utilizes the changes of peak height ratios in thermoluminescence glowcurves. Peak height ratios depend on the linear energy transfer (LET) of absorbed radiation. This effect was calibrated in different radiation fields (alpha-, beta-, gamma-, neutron fields and heavy charged particle beams). The method was approached for dose measurements during several space programs (DOSIMIR, BION-10, PHOTONS). During the Russian long term flight RLF six dosemeter packets were exposed in three different periods. Two positions with different shielding (the working area and the cabin of the board engineer) were chosen for the exposition of the dosemeters during each period in order to measure the variation of absorbed dose as well as the variation of average LET of absorbed radiation within the habitable part of space station MIR. These results will be compared with the results during two former periods of measurements on space station MIR (AUSTROMIR/DOSIMIR) and results obtained inside of biosatellite BION-10 and during the space shuttle mission STS-60. (author)

  18. Lung toxicity determination by in vitro exposure at the air liquid interface with an integrated online dose measurement

    International Nuclear Information System (INIS)

    Muelhopt, Sonja; Paur, H-R; Diabate, S; Weiss, C; Krebs, T

    2009-01-01

    Epidemiological studies show an association between the concentration of ultrafine particles in the atmosphere and the rate of mortality or morbidity due to respiratory and cardiovascular diseases. For the quantitative assessment of the toxicity of airborne nanoparticles the dose-response relationship is tested in in vitro test systems using bioassays of cell cultures as sensor. For the air-liquid interface exposure of cell cultures towards aerosols the Karlsruhe exposure system was developed. The human lung cell cultures are exposed in VITROCELL (registered) system modules with a constant flow of the conditioned aerosol. After exposure the cells are analyzed to measure the biological responses such as viability, inflammatory or oxidative stress. For the determination of the dose response relationship the accurate knowledge of the deposited particle mass is essential. A new online method is developed in the Karlsruhe exposure system: the sensor of a quartz crystal microbalance is placed in an exposure chamber instead of the membrane insert and exposed to the aerosol in the same way as the cell cultures. The deposited mass per area unit is monitored as a function of exposure time showing a linear relationship for a constant aerosol flow with defined particle concentration. A comparison of this new dose signal to a dosimetry method using fluorescein sodium particles shows a very good correlation between the sensor signal of the quartz crystal microbalance and the deposited mass on the membranes shown by spectroscopy. This system for the first time provides an online dose measurement for in vitro experiments with nanoparticles.

  19. Lethal dose determination of Cobalt-60 for adult Tribolium castaneum (Coleoptera: Tenebrionidae) and Cryptolestes ferrugineus (Coleoptera: Laemophloeidae)

    International Nuclear Information System (INIS)

    Farias, Anderson Aparecido; Potenza, Marcos Roberto; Reis, Fabricio Caldeira; Sato, Mario Eidi

    2015-01-01

    The insect infestation is a major problem in the grain storage. The pesticides are most widely used method for disinfestation and prevention. Treatment with gamma irradiation may increase the product shelf life without encountering formation of waste can be used in packaged foods and ready for commercialization, representing an important alternative to the use of pesticides. This study aimed to determine the immediate lethal dose of gamma radiation for adults of Tribolium castaneum and Cryptolestes ferrugineus. The study was conducted in the Instituto Biologico and the radiations held at the Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN, Sao Paulo city, using a multipurpose irradiator Cobalt-60 with 3.31 dose rate and 3.23 kGy in months of November/2014 and January/2015. Each experimental unit consisted of 20 adult insects, confined in a 10 mL polyethylene container. The experimental plots in number 10 per dose were subjected to increasing doses of gamma radiation: 0; 0.5; 0.75; 1.0; 1.25; 1.50; 1.75; 2.00; 2:50 and 3.00 kGy. Mortality was assessed within two to four hours after irradiation. The data were submitted to Probit analysis, using the POLO PLUS program. The LD90 to control 90% (LD90) to control adult Cryptolestes ferrugineus and Tribolium castaneum were 2.73 and 2.91 kGy, respectively. (author)

  20. A search for new CYP3A4 variants as determinants of tacrolimus dose requirements in renal-transplanted patients.

    Science.gov (United States)

    Tavira, Beatriz; Coto, Eliecer; Diaz-Corte, Carmen; Alvarez, Victoria; López-Larrea, Carlos; Ortega, Francisco

    2013-08-01

    The CYP3A5*3 and CYP3A4*1B alleles have been related with tacrolimus (Tac) dose requirements. The rare CYP3A4*22 variant has also been associated with a significantly lower Tac dose. We genotyped the three single-nucleotide polymorphisms in 206 kidney-transplanted patients who received Tac as the primary immunosuppressor. CYP3A5*1 and CYP3A4*1B allele carriers received a significantly higher Tac dose (PCYP3A4*22 genotypes, either nominally or according to the CYP3A5 genotype (expressers vs. nonexpressers). Sequencing of CYP3A4 coding exons in a total of 15 patients revealed only one nonreported missense change (p.P227>T) in one patient. We concluded that CYP3A5*3 and CYP3A4*1B were the main determinants of the Tac dose-adjusted blood concentration in our cohort of renal-transplanted patients.

  1. Lethal dose determination of Cobalt-60 for adult Tribolium castaneum (Coleoptera: Tenebrionidae) and Cryptolestes ferrugineus (Coleoptera: Laemophloeidae)

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Anderson Aparecido, E-mail: potenza@biologico.sp.gov.br [Instituto Biologico, Centro de Pesquisa e Desenvolvimento de Protecao Ambiental, Sao Paulo, SP (Brazil); Potenza, Marcos Roberto, E-mail: fcreis@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Reis, Fabricio Caldeira; Sato, Mario Eidi, E-mail: mesato@biologico.sp.gov.br [Instituto Biologico, Centro Experimental Central, Laboratorio de Acarologia, Campinas, SP (Brazil)

    2015-07-01

    The insect infestation is a major problem in the grain storage. The pesticides are most widely used method for disinfestation and prevention. Treatment with gamma irradiation may increase the product shelf life without encountering formation of waste can be used in packaged foods and ready for commercialization, representing an important alternative to the use of pesticides. This study aimed to determine the immediate lethal dose of gamma radiation for adults of Tribolium castaneum and Cryptolestes ferrugineus. The study was conducted in the Instituto Biologico and the radiations held at the Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN, Sao Paulo city, using a multipurpose irradiator Cobalt-60 with 3.31 dose rate and 3.23 kGy in months of November/2014 and January/2015. Each experimental unit consisted of 20 adult insects, confined in a 10 mL polyethylene container. The experimental plots in number 10 per dose were subjected to increasing doses of gamma radiation: 0; 0.5; 0.75; 1.0; 1.25; 1.50; 1.75; 2.00; 2:50 and 3.00 kGy. Mortality was assessed within two to four hours after irradiation. The data were submitted to Probit analysis, using the POLO PLUS program. The LD90 to control 90% (LD90) to control adult Cryptolestes ferrugineus and Tribolium castaneum were 2.73 and 2.91 kGy, respectively. (author)

  2. Abdominal multi-detector row CT: Effectiveness of determining contrast medium dose on basis of body surface area

    International Nuclear Information System (INIS)

    Onishi, Hiromitsu; Murakami, Takamichi; Kim, Tonsok; Hori, Masatoshi; Osuga, Keigo; Tatsumi, Mitsuaki; Higashihara, Hiroki; Maeda, Noboru; Tsuboyama, Takahiro; Nakamoto, Atsushi; Tomoda, Kaname; Tomiyama, Noriyuki

    2011-01-01

    Purpose: To investigate the validity of determining the contrast medium dose based on body surface area (BSA) for the abdominal contrast-enhanced multi-detector row CT comparing with determining based on body weight (BW). Materials and methods: Institutional review committee approval was obtained. In this retrospective study, 191 patients those underwent abdominal contrast-enhanced multi-detector row CT were enrolled. All patients received 96 mL of 320 mg I/mL contrast medium at the rate of 3.2 mL. The iodine dose required to enhance 1 HU of the aorta at the arterial phase and that of liver parenchyma at portal venous phase per BSA were calculated (EU BSA ) and evaluated the relationship with BSA. Those per BW were also calculated (EU BW ) and evaluated. Estimated enhancement values (EEVs) of the aorta and liver parenchyma with two protocols for dose decision based on BSA and BW were calculated and patient-to-patient variability was compared between two protocols using the Levene test. Results: The mean of EU BSA and EU BW were 0.0621 g I/m 2 /HU and 0.00178 g I/kg/HU for the aorta, and 0.342 g I/m 2 /HU and 0.00978 g I/kg/HU for the liver parenchyma, respectively. In the aortic enhancement, EU BSA was almost constant regardless of BSA, and the mean absolute deviation of the EEV with the BSA protocol was significantly lower than that with the BW protocol (P < .001), although there was no significant difference between two protocols in the hepatic parenchymal enhancement (P = .92). Conclusion: For the aortic enhancement, determining the contrast medium dose based on BSA was considered to improve patient-to-patient enhancement variability.

  3. Contract-related dose determination in the Biblis nuclear power station of the RWE

    International Nuclear Information System (INIS)

    Kallmeyer, D.; Ambros, R.

    1979-01-01

    An important method of control (and hence reduction) of the exposure to radiation is the work- or contract-related dosage determination. (ADOS). The aim of ADOS in the detailed determination of the dosage to which personnel is exposed during all operations in the controlled area, and the allocation of this dosage to the operations in the controlled zone. The authors describe the methodology and give selected results from a computerised acquisition system for the contract-related dosage determination. (orig.) [de

  4. Determination of internal radiation dose due to intake of polonium 210 and lead 210 via smoking

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Kharita, M.H.; Nashawati, A.; Amin, Y.; Al-Akel, B.

    2004-12-01

    In this study, 18 kind of cigarettes and five kinds of molasses consumed by Syrians were collected and analyzed for radioactivity in order to estimate the internal radiation dose caused by 210 Po and 210 Pb intake. Polonium 210 and lead 210 concentrations varied between 4 and 16.4 m Bq/cigarette, while 210 Po distribution ratios in different parts of consumed cigarette were %12, %73, %1.6 in ash, smoke and filter, respectively. In addition, annual intake of 210 Po by a main smoker was varied between 4.4 and 18 Bq/year assuming that the main smoker breathes about 15% of the total 210 Po present in tobacco. Using the values of the annual intake, annual equivalent radiation dose caused by smoking has reached 178 μSv/year. Moreover, mean concentration of 210 Po in nonsmokers and smokers bloods has reached 130 and 97 mBq/l, respectively, while the mean value of 210 Po concentration was relatively higher and reached 176 and 155 mBq/l in smokers and non smoker bloods, respectively (Authors)

  5. Can non-destructive inspection be reliable

    International Nuclear Information System (INIS)

    Silk, M.G.; Stoneham, A.M.; Temple, J.A.G.

    1988-01-01

    The paper on inspection is based on the book ''The reliability of non-destructive inspection: assessing the assessment of structures under stress'' by the present authors (published by Adam Hilger 1987). Emphasis is placed on the reliability of inspection and whether cracks in welds or flaws in components can be detected. The need for non-destructive testing and the historical attitudes to non-destructive testing are outlined, along with the case of failure. Factors influencing reliable inspection are discussed, and defect detection trials involving round robin tests are described. The development of reliable inspection techniques and the costs of reliability and unreliability are also examined. (U.K.)

  6. Nondestructive assay measurements applied to reprocessing plants

    International Nuclear Information System (INIS)

    Ruhter, Wayne D.; Lee, R. Stephen; Ottmar, Herbert; Guardini, Sergio

    1999-01-01

    Nondestructive assay for reprocessing plants relies on passive gamma-ray spectrometry for plutonium isotopic and plutonium mass values of medium-to-low-density samples and holdup deposits; on active x-ray fluorescence and densitometry techniques for uranium and plutonium concentrations in solutions; on calorimetry for plutonium mass in product; and passive neutron techniques for plutonium mass in spent fuel, product, and waste. This paper will describe the radiation-based nondestructive assay techniques used to perform materials accounting measurements. The paper will also discuss nondestructive assay measurements used in inspections of reprocessing plants [ru

  7. A passive dosing method to determine fugacity capacities and partitioning properties of leaves

    DEFF Research Database (Denmark)

    Bolinius, Damien Johann; Macleod, Matthew; McLachlan, Michael S.

    2016-01-01

    The capacity of leaves to take up chemicals from the atmosphere and water influences how contaminants are transferred into food webs and soil. We provide a proof of concept of a passive dosing method to measure leaf/polydimethylsiloxane partition ratios (Kleaf/PDMS) for intact leaves, using...... polychlorinated biphenyls (PCBs) as model chemicals. Rhododendron leaves held in contact with PCB-loaded PDMS reached between 76 and 99% of equilibrium within 4 days for PCBs 3, 4, 28, 52, 101, 118, 138 and 180. Equilibrium Kleaf/PDMS extrapolated from the uptake kinetics measured over 4 days ranged from 0...... the variability in sorptive capacities of leaves that would improve descriptions of uptake of chemicals by leaves in multimedia fate models....

  8. Application of polystyrene - water calorimeter in determination of absorbed dose. Vol. 4.

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, F A [Nuclear Materials Authority, Maadi, Cairo (Egypt); Ashry, H A; El-Behay, A Z; Abdou, S [National Center, for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    The polystyrene-water calorimeter was investigated as a modification of the water calorimeter, where the polystyrene has a low specific heat and negligible known heat defect. This calorimeter was designed, constructed and calibrated for measurement of radiation absorbed dose. The system utilizes a thermistor to detect the radiation-induced temperature rise in the polystyrene absorber at certain point from the radiation source. A temperature stability of as low as 0.0018 degree C/min in a 42.0 degree C environment, and a gamma-radiation sensitivity of as high as 1.9720 ohm/Gy were obtained. Comparisons of the results obtained by using the polystyrene-water calorimeter with those obtained by applying other types of calorimeters i.e., water and graphite calorimeters were also done to aid in the possible realization of an accurate and efficient instrument for use under widely different irradiation conditions. 4 figs., 1 tab.

  9. Integration of Fricke gel dosimetry with Ag nanoparticles for experimental dose enhancement determination in theranostics

    International Nuclear Information System (INIS)

    Vedelago, J.; Valente, M.; Mattea, F.

    2017-10-01

    The use and implementation of nanoparticles in medicine has grown exponentially in the last twenty years. Their main applications include drug delivery, theranostics, tissue engineering and magneto function. Dosimetry techniques can take advantage of inorganic nanoparticles properties and their combination with gel dosimetry techniques could be used as a first step for their later inclusion in radio-diagnostics or radiotherapy treatments. This work presents preliminary results of properly synthesized and purify silver nanoparticles integration with Fricke gel dosimeters. Used nanoparticles presented mean sizes ranging from 2 to 20 nm, with a lognormal distribution. Xylenol orange concentration in Fricke gel dosimeter was adjust in order to allow sample optical readout, accounting nanoparticles plasmon. Dose enhancement was assessed irradiating dosimeters setting X-ray beams energies below and above silver K-edge. (Author)

  10. Integration of Fricke gel dosimetry with Ag nanoparticles for experimental dose enhancement determination in theranostics

    Energy Technology Data Exchange (ETDEWEB)

    Vedelago, J.; Valente, M. [Instituto de Fisica Enrique Gaviola - CONICET, Av. Medina Allende s/n, Ciudad Universitaria, X5000HUA Cordoba (Argentina); Mattea, F., E-mail: jvedelago@famaf.unc.edu.ar [Universidad Nacional de Cordoba, FAMAF, Laboratorio de Investigacion e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Av. Medina Allende s/n, Ciudad Universitaria, X5000HUA Cordoba (Argentina)

    2017-10-15

    The use and implementation of nanoparticles in medicine has grown exponentially in the last twenty years. Their main applications include drug delivery, theranostics, tissue engineering and magneto function. Dosimetry techniques can take advantage of inorganic nanoparticles properties and their combination with gel dosimetry techniques could be used as a first step for their later inclusion in radio-diagnostics or radiotherapy treatments. This work presents preliminary results of properly synthesized and purify silver nanoparticles integration with Fricke gel dosimeters. Used nanoparticles presented mean sizes ranging from 2 to 20 nm, with a lognormal distribution. Xylenol orange concentration in Fricke gel dosimeter was adjust in order to allow sample optical readout, accounting nanoparticles plasmon. Dose enhancement was assessed irradiating dosimeters setting X-ray beams energies below and above silver K-edge. (Author)

  11. Identification and dose determination using ESR measurements in the flesh of irradiated vegetable products

    International Nuclear Information System (INIS)

    Jesus, E.F.O. de; Rossi, A.M.; Lopes, R.T.

    2000-01-01

    The international commerce of vegetable products is often dependent on the quarantine protections that are imposed by the importing countries because of the fear of contamination by fruit flies. The use of ionizing radiation as a treatment for these products can be used to remove this problem and a real proof of irradiation can contribute to the implementation of the international commerce. ESR measurement on the pulp of vegetable products can be used as a proof of irradiation using the species introduced in cellulose that are found uniquely in irradiated products. The stability of these species are compatible with the life of the products analyzed. The pulp signal intensity is sufficient to identify products irradiated with doses as low as 100 Gy for some fruits

  12. Use of AERIN code for determining internal doses of transuranic isotopes

    International Nuclear Information System (INIS)

    King, W.C.

    1980-01-01

    The AERIN computer code is a mathematical expression of the ICRP Lung Model. The code was developed at the Lawrence Livermore National Laboratory to compute the body organ burdens and absorbed radiation doses resulting from the inhalation of transuranic isotopes and to predict the amount of activity excreted in the urine and feces as a function of time. Over forty cases of internal exposure have been studied using the AERIN code. The code, as modified, has proven to be extremely versatile. The case studies presented demonstrate the excellent correlation that can be obtained between code predictions and observed bioassay data. In one case study a discrepancy was observed between an in vivo count of the whole body and the application of the code using urine and fecal data as input. The discrepancy was resolved by in vivo skull counts that showed the code had predicted the correct skeletal burden

  13. Determining the behavioural dose-response relationship of marine mammals to air gun noise and source proximity.

    Science.gov (United States)

    Dunlop, Rebecca A; Noad, Michael J; McCauley, Robert D; Scott-Hayward, Lindsay; Kniest, Eric; Slade, Robert; Paton, David; Cato, Douglas H

    2017-08-15

    The effect of various anthropogenic sources of noise (e.g. sonar, seismic surveys) on the behaviour of marine mammals is sometimes quantified as a dose-response relationship, where the probability of an animal behaviourally 'responding' (e.g. avoiding the source) increases with 'dose' (or received level of noise). To do this, however, requires a definition of a 'significant' response (avoidance), which can be difficult to quantify. There is also the potential that the animal 'avoids' not only the source of noise but also the vessel operating the source, complicating the relationship. The proximity of the source is an important variable to consider in the response, yet difficult to account for given that received level and proximity are highly correlated. This study used the behavioural response of humpback whales to noise from two different air gun arrays (20 and 140 cubic inch air gun array) to determine whether a dose-response relationship existed. To do this, a measure of avoidance of the source was developed, and the magnitude (rather than probability) of this response was tested against dose. The proximity to the source, and the vessel itself, was included within the one-analysis model. Humpback whales were more likely to avoid the air gun arrays (but not the controls) within 3 km of the source at levels over 140 re. 1 µPa 2  s -1 , meaning that both the proximity and the received level were important factors and the relationship between dose (received level) and response is not a simple one. © 2017. Published by The Company of Biologists Ltd.

  14. Determination of an optimal dose of medetomidine-ketamine-buprenorphine for anaesthesia in the Cape ground squirrel (Xerus inauris

    Directory of Open Access Journals (Sweden)

    K. E. Joubert

    2011-04-01

    Full Text Available The optimal dose of medetomidine-ketamine-buprenorphine was determined in 25 Cape ground squirrels (Xerus inauris undergoing surgical implantation of a temperature logger into the abdominal cavity. At the end of anaesthesia, the squirrels were given atipamezole intramuscularly to reverse the effects of medetomidine. The mean dose of medetomidine was 67.6±9.2 μg/kg, ketamine 13.6±1.9 mg/kg and buprenorphine 0.5±0.06 μg/kg. Induction time was 3.1 ± 1.4 min. This produced surgical anaesthesia for 21± 4.2 min. Atipamezole 232±92 μg/kg produced a rapid recovery. Squirrels were sternally recumbent in 3.5 ± 2.2 min.

  15. Determination of effective dose in anisotropic gamma radiation fields: application of dosimeters calibrated in terms of Hp(10)

    International Nuclear Information System (INIS)

    Chumak, V. V.; Bakhanova, E. V.

    2003-01-01

    In this presentation authors deals with determination of effective dose in anisotropic gamma radiation fields. It was conclude that: - Straightforward application of Hp(10) as surrogate for E may not work under certain conditions; - Partial data on behavior of E and Hp(10) for different dosimeters allow to estimate E/Hp(10) conversion coefficients for any particular composite source; - In practical situations, anisotropy of workplace fields may be measured by six- collimator device assessing contribution to a dose from six orthogonal directions; - Reasonably conservative conversion coefficients may be assessed for given energy spectrum and degree of anisotropy of workplace fields; - For strongly anisotropic fields multiple dosimetry approach gives the best estimate of E comparing to plain Hp(10) readouts or integral conversion coefficients

  16. Non-destructive elecrochemical monitoring of reinforcement corrosion

    DEFF Research Database (Denmark)

    Nygaard, Peter Vagn

    been widely accepted as a non-destructive ”state of the art” technique for detection of corrosion in concrete structures. And, over the last decade, the trend in corrosion monitoring has moved towards quantitative non-destructive monitoring of the corrosion rate of the steel reinforcement. A few...... corrosion rate measurement instruments have been developed and are commercially available. The main features of these instruments are the combined use of an electrochemical technique for determining the corrosion rate and a so-called ”confinement technique”, which in principle controls the polarised surface...... area of the reinforcement, i.e. the measurement area. Both on-site investigations and laboratory studies have shown that varying corrosion rates are obtained when the various commercially available instruments are used. And in the published studies, conflicting explanations are given illustrating...

  17. Aging management of major LWR components with nondestructive evaluation

    International Nuclear Information System (INIS)

    Shah, V.N.; MacDonald, P.E.; Akers, D.W.; Sellers, C.; Murty, K.L.; Miraglia, P.Q.; Mathew, M.D.; Haggag, F.M.

    1997-01-01

    Nondestructive evaluation of material damage can contribute to continued safe, reliable, and economical operation of nuclear power plants through their current and renewed license period. The aging mechanisms active in the major light water reactor components are radiation embrittlement, thermal aging, stress corrosion cracking, flow-accelerated corrosion, and fatigue, which reduce fracture toughness, structural strength, or fatigue resistance of the components and challenge structural integrity of the pressure boundary. This paper reviews four nondestructive evaluation methods with the potential for in situ assessment of damage caused by these mechanisms: stress-strain microprobe for determining mechanical properties of reactor pressure vessel and cast stainless materials, magnetic methods for estimating thermal aging damage in cast stainless steel, positron annihilation measurements for estimating early fatigue damage in reactor coolant system piping, and ultrasonic guided wave technique for detecting cracks and wall thinning in tubes and pipes and corrosion damage to embedded portion of metal containments

  18. Slit x-ray beam primary dose profiles determined by analytical transport of Compton recoil electrons

    NARCIS (Netherlands)

    van't Veld, AA; van Luijk, P; Praamstra, F; van der Hulst, PC

    Accurate measurement of radiation beam penumbras is essential for conformal radiotherapy. For this purpose a detailed knowledge of the dosimeter's spatial response is required. However, experimental determination of detector spatial response is cumbersome and restricted to the specific detector type

  19. Tutoring system for nondestructive testing using computer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Koo; Koh, Sung Nam [Joong Ang Inspection Co.,Ltd., Seoul (Korea, Republic of); Shim, Yun Ju; Kim, Min Koo [Dept. of Computer Engineering, Aju University, Suwon (Korea, Republic of)

    1997-10-15

    This paper is written to introduce a multimedia tutoring system for nondestructive testing using personal computer. Nondestructive testing, one of the chief methods for inspecting welds and many other components, is very difficult for the NDT inspectors to understand its technical basis without a wide experience. And it is necessary for considerable repeated education and training for keeping their knowledge. The tutoring system that can simulate NDT works is suggested to solve the above problem based on reasonable condition. The tutoring system shows basic theories of nondestructive testing in a book-style with video images and hyper-links, and it offers practices, in which users can simulate the testing equipment. The book-style and simulation practices provide effective and individual environments for learning nondestructive testing.

  20. Tutoring system for nondestructive testing using computer

    International Nuclear Information System (INIS)

    Kim, Jin Koo; Koh, Sung Nam; Shim, Yun Ju; Kim, Min Koo

    1997-01-01

    This paper is written to introduce a multimedia tutoring system for nondestructive testing using personal computer. Nondestructive testing, one of the chief methods for inspecting welds and many other components, is very difficult for the NDT inspectors to understand its technical basis without a wide experience. And it is necessary for considerable repeated education and training for keeping their knowledge. The tutoring system that can simulate NDT works is suggested to solve the above problem based on reasonable condition. The tutoring system shows basic theories of nondestructive testing in a book-style with video images and hyper-links, and it offers practices, in which users can simulate the testing equipment. The book-style and simulation practices provide effective and individual environments for learning nondestructive testing.

  1. Direct determination of the absorbed dose to water from 125I low dose-rate brachytherapy seeds using the new absorbed dose primary standard developed at ENEA-INMRI

    International Nuclear Information System (INIS)

    Toni, M.P.; Pimpinella, M.; Pinto, M.; Quini, M.; Cappadozzi, G.; Silvestri, C.; Bottauscio, O.

    2012-01-01

    Low-intensity radioactive sources emitting low-energy photons are used in the clinic for low dose-rate brachytherapy treatments of tumours. The dosimetry of these sources is based on reference air kerma rate measurements. The absorbed dose rate to water at the reference depth d 0 = 1 cm, D w , 1 cm, is then obtained by a conversion procedure with a large relative standard uncertainty of about 5%. This paper describes a primary standard developed at ENEA-INMRI to directly measure D w , 1 cm due to LDR sources. The standard is based on a large-angle and variable-volume ionization chamber, embedded in a graphite phantom and operating under 'wall-less air chamber' conditions. A set of correction and conversion factors, based on experiments and Monte Carlo simulations, are determined to obtain the value of D w , 1 cm from measurements of increment of ionization current with increasing chamber volume. The relative standard uncertainty on D w , 1 cm is 2.6%, which is appreciably lower than the current uncertainty. Characteristics of the standard, its associated uncertainty budget, and some experimental results are given for 125 I BEBIG I25.S16.C brachytherapy seeds. Finally, results of the experimental determination of the dose-rate constant 1 cm, traceable to the D w , 1 cm and the low-energy air kerma ENEA-INMRI standards, are given. The relative standard uncertainty on 1 cm is 2.9%, appreciably lower than the typical uncertainty (4.8%) of the values available in the literature. (authors)

  2. Development of a methodology to determine optimized therapeutic doses of {sup 131}I for the treatment of hyperthyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Francisco de; Santas, Bernardo Maranhao; Dantas, Ana Leticia Almeida; Lucena, Eder Augusto [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mail: faraujo@ird.gov.br; Melo, Rossana Corbo de; Rebelo, Ana Maria de Oliveira [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina

    2007-07-01

    Several methods can be used to determine the activity of {sup 131}I to be administered for the treatment of hyperthyroidism. However, some of them do not take into consideration the dose absorbed by the thyroid, while others do not consider all the parameters necessary for dose calculation. The relationship between the dose absorbed by the thyroid and the activity administered depends basically on three parameters: mass of the organ, iodine uptake and effective half-life of iodine in the thyroid. Such parameters should be individually determined for each patient in order to optimize the administered activity. The objective of this work is to develop a methodology to evaluate therapeutic doses through the determination of biokinetic parameters and the activity of {sup 131}I deposited in the thyroid of patients submitted to the treatment of hyperthyroidism with {sup 131}I. A neck-thyroid phantom developed at the In Vivo Monitoring Laboratory of IRD, containing a known amount of {sup 131}I, was used to calibrate a scintillation camera and a uptake probe available at the Nuclear Medicine Center of the University Hospital of Rio de Janeiro. The optimization of the counting geometry was carried out by the determination of the characteristic curves of the view angle of the collimator-detector assembly. The calculation of the calibration factor of the scintillation camera allows the determination of activities in the thyroid of patients in pre-established time periods through a 48-hours uptake curve. The view angle of the collimator-detector assembly presented values compatible with the size of the organ for distances of 25 cm (uptake probe) and 45.8 cm (scintillation camera). The calibration factors (in cpm/kBq) and the associated uncertainty related to these distances were 39.3 {+-} 0.8 and 4.3 {+-} 0.2 respectively. The time period between 14 and 30 hours of the retention curve allows the calculation of the activity between those two points. It is concluded that the use

  3. Determination of a site-specific reference dose for methylmercury for fish-eating populations.

    Science.gov (United States)

    Shipp, A M; Gentry, P R; Lawrence, G; Van Landingham, C; Covington, T; Clewell, H J; Gribben, K; Crump, K

    2000-11-01

    Environmental risk-management decisions in the U.S. involving potential exposures to methylmercury currently use a reference dose (RfD) developed by the U.S. Environmental Protection Agency (USEPA). This RfD is based on retrospective studies of an acute poisoning incident in Iraq in which grain contaminated with a methylmercury fungicide was inadvertently used in the baking of bread. The exposures, which were relatively high but lasted only a few months, were associated with neurological effects in both adults (primarily paresthesia) and infants (late walking, late talking, etc.). It is generally believed that the developing fetus represents a particularly sensitive subpopulation for the neurological effects of methylmercury. The USEPA derived an RfD of 0.1 microg/kg/day based on benchmark dose (BMD) modeling of the combined neurological endpoints reported for children exposed in utero. This RfD included an uncertainty factor of 10 to consider human pharmacokinetic variability and database limitations (lack of data on multigeneration effects or possible long-term sequelae of perinatal exposure). Alcoa signed an Administrative Order of Consent for the conduct of a remedial investigation/feasibility study (RI/FS) at their Point Comfort Operations and the adjacent Lavaca Bay in Texas to address the effects of historical discharges of mercury-containing wastewater. In cooperation with the Texas Natural Resource Conservation Commission and USEPA Region VI, Alcoa conducted a baseline risk assessment to assess potential risk to human health and the environment. As a part of this assessment. Alcoa pursued the development of a site-specific RfD for methylmercury to specifically address the potential human health effects associated with the ingestion of contaminated finfish and shellfish from Lavaca Bay. Application of the published USEPA RfD to this site is problematic; while the study underlying the RfD represented acute exposure to relatively high concentrations of

  4. Total Ambient Dose Equivalent Buildup Factor Determination for Nbs04 Concrete.

    Science.gov (United States)

    Duckic, Paulina; Hayes, Robert B

    2018-06-01

    Buildup factors are dimensionless multiplicative factors required by the point kernel method to account for scattered radiation through a shielding material. The accuracy of the point kernel method is strongly affected by the correspondence of analyzed parameters to experimental configurations, which is attempted to be simplified here. The point kernel method has not been found to have widespread practical use for neutron shielding calculations due to the complex neutron transport behavior through shielding materials (i.e. the variety of interaction mechanisms that neutrons may undergo while traversing the shield) as well as non-linear neutron total cross section energy dependence. In this work, total ambient dose buildup factors for NBS04 concrete are calculated in terms of neutron and secondary gamma ray transmission factors. The neutron and secondary gamma ray transmission factors are calculated using MCNP6™ code with updated cross sections. Both transmission factors and buildup factors are given in a tabulated form. Practical use of neutron transmission and buildup factors warrants rigorously calculated results with all associated uncertainties. In this work, sensitivity analysis of neutron transmission factors and total buildup factors with varying water content has been conducted. The analysis showed significant impact of varying water content in concrete on both neutron transmission factors and total buildup factors. Finally, support vector regression, a machine learning technique, has been engaged to make a model based on the calculated data for calculation of the buildup factors. The developed model can predict most of the data with 20% relative error.

  5. Determinants of radiological dose from Sr and Cs accumulated by tropical freshwater fish

    International Nuclear Information System (INIS)

    Twining, J.R.; Markich, S.J.; Ferris, J.M.

    1998-01-01

    Recent studies of the bioaccumulation of strontium and caesium by tropical freshwater fish were in some ways consistent with temperate data. For example, biodistribution of radionuclides and the influence of chemical analogues Ca and K were in general agreement with earlier data. However, in other matters there were systematic inconsistencies when compared with the standard IAEA models. These differences gave rise to transfer (concentration) factors for both Cs and Sr that were approximately an order of magnitude below the expected values based on temperate data (e.g. 13 and 0.7 compared with 440 and 4.7 respectively). Compatible results were found for a range of tropical species studied by different investigators. In this presentation, some of the factors believed to influence bioaccumulation, and hence radiological dose, in tropical environments are discussed in relation to the above findings. These factors include: water physico-chemistry, temperature, fish size and physiology, whether or not the data were acquired from field or laboratory studies, and how the studies were carried out. Critical group exposure pathways in tropical environments and the benefits and shortcomings of applying default temperate models of Cs and Sr accumulation by freshwater fish are also discussed. (author)

  6. Determination of the carbon content of domestic farm produces to estimate offsite C-14 ingestion dose

    International Nuclear Information System (INIS)

    Jung, Y. G.; Kim, M. J.; Lee, G. B.

    2003-01-01

    The carbon content of grains, leafy and root vegetables, and fruits which the Koreans usually eat were calculated to use in the estimation of offsite C-14 ingestion dose. With the data of food intake per day in the Report on 1998 national health and nutrition survey- dietary intake survey, 5 age-group integrate d intake of the 4 farm produce groups were extracted for food items and the amount. Intake percentage in each food group were taken as food weighing factor for the foods. Carbon content was calculated using protein, fat, and carbohydrate content of the foods, and multiplied by the corresponding food weighing factor to derive the content of the food groups. The calculated carbon content of grains, leafy and root vegetables, and fruits were 39.%, 4.2%, 8.0%, and 5.9% respectively. Grains and fruits were not much different from ODCM for carbon content, but vegetables were higher by 0.7%∼4.5%

  7. Protection dose level in industrial non-destructive radiographic testing

    International Nuclear Information System (INIS)

    Su Xieming; Deng Daping; Hou Jinpeng

    1992-01-01

    The relationship between scattered beams in radiation field, different tube-voltages, and thickness of steel plates was studied by experiments. The results show that radio parent ratio increases with increasing tube-voltage and decreases with the increasing thickness of steel plates. As scattering angle rises, the scattering ratio decreases slowly, and the lowest ratio is at 180 degree

  8. Assay of new systems in vivo mutagenesis for determining the effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Bauluz, C.; Sierra, I.; Martin, L.; Real, A.; Vidania, R. de

    1997-01-01

    Ionizing radiation reacts directly and indirectly with the genetic material in living cells and produces DNA damage. Processing of this damage by correcting enzymes may result in appearing of mutations which, in turn, may lead to carcinogenesis. We have focused on the determination of in vivo mutagenesis induced after exposure to X-rays, aiming at establishing methods to evaluate the effect of low doses of radiation. In vivo mutagenesis has been addressed in the Muta Mouse model that carries a lacZ marker gene and provides a relatively simple assay of appearance of mutations. Mutation frequencies were determined in the lacZ gene copies recovered from mice irradiated with 1Gy or 4Gy of X-rays, acute or fractionated. Liver, spleen and bone marrow DNA samples were isolated at different times after irradiation, ranging from 1 day to 2 months, and evolution of mutations was studied. Results showed different responses depending on the organ and especially on the time of analysis, suggesting that the mutagenic process in vivo is much more complex than previously deduced from in vitro experiments. Therefore, determination of the relationship between dose and mutagenic effect in vivo will require additional studies. (author)

  9. Determinants of times of appearance of radium-induced osteosarcomas in humans: age at appearance and dose

    International Nuclear Information System (INIS)

    Stebbings, J.H.; Lucas, H.F.

    1983-01-01

    Determinants of time-until-tumor for osteosarcoma in US radium cases have been reevaluated. Classically, a minimum induction period (latency period) of about five years has been recognized, but not an expression period. Lack of long induction periods at igh doses has been ascribed to scarcity of subjects at risk. Recent experiments have suggested that induction periods are directly lengthened as doses decrease. Reanalyses of time-until-tumor data for 57 measured female osteosarcoma cases exposed to 226 Ra and /or 228 Ra support new interpretations: time-until-tumor for osteosarcomas is best described by age at tumor appearance, not by induction period; age at diagnosis increases as estimated initial radium intake decreases; and, there exists an expression period which can be truncated at the low end by the minimum induction period (or by age at exposure). The downturn in sarcoma incidence at very high doses is describable as the truncation of the expression period on its early side by the minimum induction period. These results depend strongly on the assumption of homogeneity of time-until-tumor processes in diial workers and in iatrogenic radium exposure cases

  10. Distribution pattern of radon and daughters in an urban environment and determination of organ-dose frequency distributions

    International Nuclear Information System (INIS)

    Steinhaeusler, F.; Hofmann, W.; Pohl, E.; Pohl-Rueling, J.

    1980-01-01

    In a normal urban environment, inhaled radon and its decay products cause an important part of the human radiation burden not only for the respiratory tract but also for several other organs. A study was made with 729 test persons in Salzburg, Austria. Each person was questioned regarding his living activity, i.e., the mean times he spent in individual sleeping, living, and working places and the corresponding physical activities that strongly influence the respiratory minute volume and consequently the inhaled radioactivity. At all these places, the annual means of the external gamma radiation as well as of the air content of 222 Rn and its short-lived decay products were determined. From all these measurements (more than 8000) and the information obtained, mean annual organ doses were calculated for each test person. The doses due to cosmic radiation, 40 K, and other radionuclides incorporated were totaled. The range of the mean annual doses in millirems is only from 73 to 126 for gonads and 70 to 336 for the kidneys and finally reaches from 117 to 10,700 for the basal cells of the bronchial epithelium

  11. Lubricant based determination of design space for continuously manufactured high dose paracetamol tablets.

    Science.gov (United States)

    Taipale-Kovalainen, Krista; Karttunen, Anssi-Pekka; Ketolainen, Jarkko; Korhonen, Ossi

    2018-03-30

    The objective of this study was to devise robust and stable continuous manufacturing process settings, by exploring the design space after an investigation of the lubrication-based parameters influencing the continuous direct compression tableting of high dose paracetamol tablets. Experimental design was used to generate a structured study plan which involved 19 runs. The formulation variables studied were the type of lubricant (magnesium stearate or stearic acid) and its concentration (0.5, 1.0 and 1.5%). Process variables were total production feed rate (5, 10.5 and 16kg/h), mixer speed rpm (500, 850 and 1200rpm), and mixer inlet port for lubricant (A or B). The continuous direct compression tableting line consisted of loss-in-weight feeders, a continuous mixer and a tablet press. The Quality Target Product Profile (QTPP) was defined for the final product, as the flowability of powder blends (2.5s), tablet strength (147N), dissolution in 2.5min (90%) and ejection force (425N). A design space was identified which fulfilled all the requirements of QTPP. The type and concentration of lubricant exerted the greatest influence on the design space. For example, stearic acid increased the tablet strength. Interestingly, the studied process parameters had only a very minor effect on the quality of the final product and the design space. It is concluded that the continuous direct compression tableting process itself is insensitive and can cope with changes in lubrication, whereas formulation parameters exert a major influence on the end product quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Determination of absorbed dose calibration factors for therapy level electron beam ionization chambers.

    Science.gov (United States)

    McEwen, M R; Williams, A J; DuSautoy, A R

    2001-03-01

    Over several years the National Physical Laboratory (NPL) has been developing an absorbed dose calibration service for electron beam radiotherapy. To test this service, a number of trial calibrations of therapy level electron beam ionization chambers have been carried out during the last 3 years. These trials involved 17 UK radiotherapy centres supplying a total of 46 chambers of the NACP, Markus, Roos and Farmer types. Calibration factors were derived from the primary standard calorimeter at seven energies in the range 4 to 19 MeV with an estimated uncertainty of +/-1.5% at the 95% confidence level. Investigations were also carried out into chamber perturbation, polarity effects, ion recombination and repeatability of the calibration process. The instruments were returned to the radiotherapy centres for measurements to be carried out comparing the NPL direct calibration with the 1996 IPEMB air kerma based Code of Practice. It was found that, in general, all chambers of a particular type showed the same energy response. However, it was found that polarity and recombination corrections were quite variable for Markus chambers-differences in the polarity correction of up to 1% were seen. Perturbation corrections were obtained and were found to agree well with the standard data used in the IPEMB Code. The results of the comparison between the NPL calibration and IPEMB Code show agreement between the two methods at the +/-1% level for the NACP and Farmer chambers, but there is a significant difference for the Markus chambers of around 2%. This difference between chamber types is most likely to be due to the design of the Markus chamber.

  13. Determination of Radioisotope Content by Measurement of Waste Package Dose Rates - 13394

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Daiane Cristini B.; Gimenes Tessaro, Ana Paula; Vicente, Roberto [Nuclear and Energy Research Institute Brazil, Radioactive Waste Management Department IPEN/GRR, Sao Paulo. SP. (Brazil)

    2013-07-01

    The objective of this communication is to report the observed correlation between the calculated air kerma rates produced by radioactive waste drums containing untreated ion-exchange resin and activated charcoal slurries with the measured radiation field of each package. Air kerma rates at different distances from the drum surface were calculated with the activity concentrations previously determined by gamma spectrometry of waste samples and the estimated mass, volume and geometry of solid and liquid phases of each waste package. The water content of each waste drum varies widely between different packages. Results will allow determining the total activity of wastes and are intended to complete the previous steps taken to characterize the radioisotope content of wastes packages. (authors)

  14. Aortic and hepatic enhancement at multidetector CT: evaluation of optimal iodine dose determined by lean body weight.

    Science.gov (United States)

    Kondo, Hiroshi; Kanematsu, Masayuki; Goshima, Satoshi; Watanabe, Haruo; Onozuka, Minoru; Moriyama, Noriyuki; Bae, Kyongtae T

    2011-12-01

    To determine the optimal iodine dose for aortic and hepatic enhancement at MDCT by comparing lean body weight (LBW) with total body weight (TBW). This study was approved by our institutional review committee. One hundred and thirty-six patients were randomized into four groups: 550, 650, 750 mg iodine/(kg of LBW) and 600 mgI/(kg of TBW). The aortic and hepatic contrast enhancements (Δ HUs) during the portal venous-phase and variances of ΔHUs were compared. Mean ΔHUs for 550, 650, 750 mgI/kg LBW and 600 mgI/kg TBW were: 95.1, 109.9, 122.4, and 131.2HU, respectively, for the aorta. For the liver, 43.1, 55.4, 60.8, and 63.5 HU. Mean Δ HUs increased with iodine dose per kg LBW (p<0.01), but no significant difference between 750 mgI/kg LBW and 600 mgI/kg TBW groups. Hepatic enhancement increased by ≥50 HU in 94% of patients with 750 mg/kg LBW. Variance of hepatic enhancement was marginally greater in the 600 mgI/kg TBW than in the 550 and 750 mgI/kg LBW. Hepatic enhancement variation was reduced with iodine doses based on LBW. Iodine dose of 750 mg iodine/kg LBW was appropriate to achieve hepatic enhancement≥50 HU in 94% of patients. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  15. Aortic and hepatic enhancement at multidetector CT: Evaluation of optimal iodine dose determined by lean body weight

    International Nuclear Information System (INIS)

    Kondo, Hiroshi; Kanematsu, Masayuki; Goshima, Satoshi; Watanabe, Haruo; Onozuka, Minoru; Moriyama, Noriyuki; Bae, Kyongtae T.

    2011-01-01

    Purpose: To determine the optimal iodine dose for aortic and hepatic enhancement at MDCT by comparing lean body weight (LBW) with total body weight (TBW). Materials and methods: This study was approved by our institutional review committee. One hundred and thirty-six patients were randomized into four groups: 550, 650, 750 mg iodine/(kg of LBW) and 600 mgI/(kg of TBW). The aortic and hepatic contrast enhancements (ΔHUs) during the portal venous-phase and variances of ΔHUs were compared. Results: Mean ΔHUs for 550, 650, 750 mgI/kg LBW and 600 mgI/kg TBW were: 95.1, 109.9, 122.4, and 131.2 HU, respectively, for the aorta. For the liver, 43.1, 55.4, 60.8, and 63.5 HU. Mean ΔHUs increased with iodine dose per kg LBW (p < 0.01), but no significant difference between 750 mgI/kg LBW and 600 mgI/kg TBW groups. Hepatic enhancement increased by ≥50 HU in 94% of patients with 750 mg/kg LBW. Variance of hepatic enhancement was marginally greater in the 600 mgI/kg TBW than in the 550 and 750 mgI/kg LBW. Conclusion: Hepatic enhancement variation was reduced with iodine doses based on LBW. Iodine dose of 750 mg iodine/kg LBW was appropriate to achieve hepatic enhancement ≥50 HU in 94% of patients.

  16. Using thermoluminescence dosimetry (TLD) to determine the gonadal dose of patients under-going chest X-ray examinations at NKST hospital, Mkar

    International Nuclear Information System (INIS)

    Agba, E.H.; Akaagerger, N.B.; Kungur, S.T.

    2011-01-01

    The doses absorbed by the gonads of patients undergoing chest X-ray examinations at NKST Christian Hospital, Mkar was determined using the Thermoluminescence Dosimetry Technique of measurement. Also, the direct X-ray dose to the chest of patients undergoing the routine examinations was also determined using the Thermolumnescence Dosimetry technique of measurement. The mean gonadal dose and the X-ray dose to the patients were found to be 0.03±0.02μSv and 0.04±0.03mSv respectively after exposure. These X-ray doses to the patients is seen to be within the acceptable recommended X -ray dose limits of 1mGy recommended by ICRP.

  17. A simple calculation for the determination of organ or tissue dose from medical x-ray diagnosis for stomach and chest

    International Nuclear Information System (INIS)

    Nishizawa, Kanae

    1984-01-01

    A simple calculation method has been developed to determine the organ or tissue doses of patients for typical X-ray diagnoses. The absorbed doses related to radiation-induced stochastic effects were calculated based on the dosimetric parameters experimentally determined and technical parameters for X-ray diagnostic examinations. The present method is principally based on the TRA method for the beam therapy. The dosimetric parameters such as percentage depth-dose curves and isodose curves were measured with ionization chambers in the MixDP phantom. The distance from the incident surface of X-ray beams to the organ or tissue of interest was determined with a mathematical phantom, which was the modified version of the MIRD phantom for the average Japanese adult. The absorbed doses were determined with a simple table look-up method using a computer. The calculated doses were tabulated for various technical parameters of stomach and chest X-ray examinations. The present calculation was applied to the Rando woman phantom to compare with the phantom measurements. The calculated values agree with the experimental doses within 20% discrepancy. It was concluded that the present calculation method can determine organ or tissue doses very simply for various X-ray examinations and that it was valuable for the estimation of population doses and risks from X-ray diagnoses. (author)

  18. Nondestructive assay methods for irradiated nuclear fuels

    International Nuclear Information System (INIS)

    Hsue, S.T.; Crane, T.W.; Talbert, W.L. Jr.; Lee, J.C.

    1978-01-01

    This report is a review of the status of nondestructive assay (NDA) methods used to determine burnup and fissile content of irradiated nuclear fuels. The gamma-spectroscopy method measures gamma activities of certain fission products that are proportional to the burnup. Problems associated with this method are migration of the fission products and gamma-ray attenuation through the relatively dense fuel material. The attenuation correction is complicated by generally unknown activity distributions within the assemblies. The neutron methods, which usually involve active interrogation and prompt or delayed signal counting, are designed to assay the fissile content of the spent-fuel elements. Systems to assay highly enriched spent-fuel assemblies have been tested extensively. Feasibility studies have been reported of systems to assay light-water reactor spent-fuel assemblies. The slowing-down spectrometer and neutron resonance absorption methods can distinguish between the uranium and plutonium fissile contents, but they are limited to the assay of individual rods. We have summarized the status of NDA techniques for spent-fuel assay and present some subjects in need of further investigation. Accuracy of the burnup calculations for power reactors is also reviewed

  19. Proficiency Testing in Nondestructive Testing (NDT)

    International Nuclear Information System (INIS)

    Amry Amin Abbas; Suhairy Sani; Mohamad Pauzi Ismail; Abd Nassir Ibrahim

    2014-01-01

    Department of Standard Malaysia (DSM) launched myPTP programme on 31 December 2013 in accordance to ISO/IC 17043. The standard states the requirements for Proficiency Testing. The provider of these services is called Proficiency Testing Provider (PTP). The role of PTP is to compare the proficiency level between inspection bodies or laboratories. With the assistance of expert panel, the PTP will determine the assigned value as reference to be compared to the values obtained from the inspection bodies or laboratories. Quality wise, this services is important as participation will improve wuality of the inspection quality continuously and increase confidence level of client and improve safety level. Requirement of PT in NDT is mentioned in SC1.5- Specific Criteria for Accreditation of Mechanical Testing and Non-Destructive Testing (NDT) for MS ISO/IEC17025 and MTR2- MIBAS Technical Requirements for Accreditation of NDT. This paper explains and discusses the result of this proficiency test done on a number of NDT companies that participated. (author)

  20. Standard specification for agencies performing nondestructive testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This specification covers minimum requirements for agencies performing nondestructive testing (NDT). 1.2 When using this specification to assess the capability of, or to accredit NDT agencies, Guide E 1359 shall be used as a basis for the survey. It can be supplemented as necessary with more detail in order to meet the auditor's specific needs. 1.3 This specification can be used as a basis to evaluate testing or inspection agencies, or both, and is intended for use for the qualifying or accrediting, or both, of testing or inspection agencies, public or private. 1.4 The use of SI or inch-pound units, or combination thereof, will be the responsibility of the technical committee whose standards are referred to in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to...

  1. The effects of intra-cerebroventricular administered rocuronium on the central nervous system of rats and determination of its epileptic seizure-inducing dose.

    Science.gov (United States)

    Baykal, Mehmet; Gökmen, Necati; Doğan, Alper; Erbayraktar, Serhat; Yılmaz, Osman; Ocmen, Elvan; Erdost, Hale Aksu; Arkan, Atalay

    The aim of this study was to investigate the effects of intracerebroventricularly administered rocuronium bromide on the central nervous system, determine the seizure threshold dose of rocuronium bromide in rats, and investigate the effects of rocuronium on the central nervous system at 1/5, 1/10, and 1/100 dilutions of the determined seizure threshold dose. A permanent cannula was placed in the lateral cerebral ventricle of the animals. The study was designed in two phases. In the first phase, the seizure threshold dose of rocuronium bromide was determined. In the second phase, Group R 1/5 (n=6), Group 1/10 (n=6), and Group 1/100 (n=6) were formed using doses of 1/5, 1/10, and 1/100, respectively, of the obtained rocuronium bromide seizure threshold dose. The rocuronium bromide seizure threshold value was found to be 0.056±0.009μmoL. The seizure threshold, as a function of the body weight of rats, was calculated as 0.286μmoL/kg -1 . A dose of 1/5 of the seizure threshold dose primarily caused splayed limbs, posturing, and tremors of the entire body, whereas the dose of 1/10 of the seizure threshold dose caused agitation and shivering. A dose of 1/100 of the seizure threshold dose was associated with decreased locomotor activity. This study showed that rocuronium bromide has dose-related deleterious effects on the central nervous system and can produce dose-dependent excitatory effects and seizures. Published by Elsevier Editora Ltda.

  2. [The effects of intra-cerebroventricular administered rocuronium on the central nervous system of rats and determination of its epileptic seizure-inducing dose].

    Science.gov (United States)

    Baykal, Mehmet; Gökmen, Necati; Doğan, Alper; Erbayraktar, Serhat; Yılmaz, Osman; Ocmen, Elvan; Erdost, Hale Aksu; Arkan, Atalay

    The aim of this study was to investigate the effects of intracerebroventricularly administered rocuronium bromide on the central nervous system, determine the seizure threshold dose of rocuronium bromide in rats, and investigate the effects of rocuronium on the central nervous system at 1/5, 1/10, and 1/100 dilutions of the determined seizure threshold dose. A permanent cannula was placed in the lateral cerebral ventricle of the animals. The study was designed in two phases. In the first phase, the seizure threshold dose of rocuronium bromide was determined. In the second phase, Group R 1/5 (n=6), Group 1/10 (n=6), and Group 1/100 (n=6) were formed using doses of 1/5, 1/10, and 1/100, respectively, of the obtained rocuronium bromide seizure threshold dose. The rocuronium bromide seizure threshold value was found to be 0.056±0.009μmoL. The seizure threshold, as a function of the body weight of rats, was calculated as 0.286μmoL/kg -1 . A dose of 1/5 of the seizure threshold dose primarily caused splayed limbs, posturing, and tremors of the entire body, whereas the dose of 1/10 of the seizure threshold dose caused agitation and shivering. A dose of 1/100 of the seizure threshold dose was associated with decreased locomotor activity. This study showed that rocuronium bromide has dose-related deleterious effects on the central nervous system and can produce dose-dependent excitatory effects and seizures. Publicado por Elsevier Editora Ltda.

  3. Use of secondary phosphorescence for determination of the dose absorbed in dosimetric phosphors

    CERN Document Server

    Yaek, I V

    2002-01-01

    The measuring method of optically stimulated persistence (OSP) based on both the time division of the stimulating irradiation and luminescent response registration was applied for the radiation dosimetry. It was shown that the stimulation by the short-wave radiation crossing with spectrum of the dosimetric phosphor is possible. The spectrum of the stimulation of industry dosimetric phosphors was measured. The characteristics of the OSP registration for the phosphors which has manganese Mn sup 2 sup + as the activator is considered. Decay time of inner center luminescence is 40-50 ms. This method is used for the dosimetry of the natural quartzes to determine their age.

  4. Nondestructive Characterization of Aged Components

    Energy Technology Data Exchange (ETDEWEB)

    Panetta, Paul D.; Toloczko, Mychailo B.; Garner, Francis A.; Balachov, Iouri I.

    2003-10-21

    may be used for material properties measurements. A more appealing solution is to use nondestructive evaluation (NDE) methods.

  5. A test of the IAEA code of practice for absorbed dose determination in photon and electron beams

    International Nuclear Information System (INIS)

    Leitner, A.; Tiefenboeck, W.; Witzani, J.; Strachotinsky, C.

    1990-12-01

    The IAEA Code of Practice TRS 277 gives recommendations for absorbed dose determination in high energy photon and electron beams based on the use of ionisation chambers calibrated in terms of exposure or air kerma. The scope of the present work was to test the Code for 60 Co gamma radiation and for several radiation qualities at four different types of electron accelerators and to compare the ionisation chamber dosimetry with ferrous sulphate dosimetry. The results show agreement between the two methods within about one per cent for all the investigated qualities. In addition the response of the TLD capsules of the IAEA/WHO TL dosimetry service has been determined. (Authors) 5 refs., 9 tabs., 3 figs

  6. Development of a Reference System for the determination of the personal dose equivalent and the constancy of X- Ray beams

    International Nuclear Information System (INIS)

    Vivolo, Vitor

    2006-01-01

    A reference system for the determination of the personal dose equivalent, Hp (10), and a quality control program of X-ray equipment used In radioprotection require the periodic verification of the X-ray beams constancy. In this work, two parallel-plate ionization chambers were developed with inner electrodes of different materials, and inserted into PMMA slab phantoms. One ionization chamber was developed with inner carbon electrodes and the other with inner aluminium electrodes. The two ionization chambers can be used as a Tandem system. The different energy response of the two ionization chambers allowed the development of the Tandem system that is very useful for the checking of the constancy of beam qualities. Standard intermediary energy X-ray beams (from 48 keV to 118 keV), radioprotection level, were established through the development of a dosimetric methodology and the analysis of their physical parameters. The ionization chambers were studied in relation to their operational characteristics, and they were calibrated in X-ray beams (radioprotection, diagnostic radiology, mammography and radiotherapy levels) in accordance to international recommendations. They presented good performance. The determination procedure of personal dose equivalent, Hp (10), was established. (author)

  7. Determination of dose correction factor for energy and directional dependence of the MOSFET dosimeter in an anthropomorphic phantom

    International Nuclear Information System (INIS)

    Cho, Sung Koo; Choi, Sang Hyoun; Kim, Chan Hyeong; Na, Seong Ho

    2006-01-01

    In recent years, the MOSFET dosimeter has been widely used in various medical applications such as dose verification in radiation therapeutic and diagnostic applications. The MOSFET dosimeter is, however, mainly made of silicon and shows some energy dependence for low energy photons. Therefore, the MOSFET dosimeter tends to overestimate the dose for low energy scattered photons in a phantom. This study determines the correction factors to compensate these dependences of the MOSFET dosimeter in ATOM phantom. For this, we first constructed a computational model of the ATOM phantom based on the 3D CT image data of the phantom. The voxel phantom was then implemented in a Monte Carlo simulation code and used to calculate the energy spectrum of the photon field at each of the MOSFET dosimeter locations in the phantom. Finally, the correction factors were calculated based on the energy spectrum of the photon field at the dosimeter locations and the pre-determined energy and directional dependence of the MOSFET dosimeter. Our result for 60 Co and 137 Cs photon fields shows that the correction factors are distributed within the range of 0.89 and 0.97 considering all the MOSFET dosimeter locations in the phantom

  8. Using the benchmark dose (BMD) methodology to determine an appropriate reduction of certain ingredients in food products.

    Science.gov (United States)

    Bi, Jian

    2010-01-01

    As the desire to promote health increases, reductions of certain ingredients, for example, sodium, sugar, and fat in food products, are widely requested. However, the reduction is not risk free in sensory and marketing aspects. Over reduction may change the taste and influence the flavor of a product and lead to a decrease in consumer's overall liking or purchase intent for the product. This article uses the benchmark dose (BMD) methodology to determine an appropriate reduction. Calculations of BMD and one-sided lower confidence limit of BMD are illustrated. The article also discusses how to calculate BMD and BMDL for over dispersed binary data in replicated testing based on a corrected beta-binomial model. USEPA Benchmark Dose Software (BMDS) were used and S-Plus programs were developed. The method discussed in the article is originally used to determine an appropriate reduction of certain ingredients, for example, sodium, sugar, and fat in food products, considering both health reason and sensory or marketing risk.

  9. In-situ gamma spectrometry method for determination of environmental gamma dose

    International Nuclear Information System (INIS)

    Conti, Claudio de Carvalho

    1995-07-01

    This work tries to establish a methodology for germanium detectors calibration, normally used for in situ gamma ray spectrometry, for determining the environmental exposure rate in function of the energy of the incident photons. For this purpose a computer code has been developed, based on the stripping method, for the computational spectra analysis to calculate the contribution of the partial absorption of the gamma rays (Compton effect) in the active and nonactive parts of the detector. The resulting total absorption spectrum is then converted to fluence distribution in function of the energy for the photons reaching the detector, which is then used to calculate the exposure rate or kerma in air. The unfolding and fluency convention parameters are determined by detector calibration using point gamma sources. The method is validated by comparison of the results against the calculated exposure rate at a point of interest for the standards. This method is used for the direct measurement of the exposure rate distribution in function of the energy at the site, in situ measurement technic, leading to rapid results during an emergency situation and also used for indoor measurements. (author)

  10. Determination of the Median Lethal Dose and Electrophoretic Pattern of Hottentotta saulcyi (Scorpiones, Buthidae Scorpion Venom

    Directory of Open Access Journals (Sweden)

    ErsenAydın Yağmur

    2015-10-01

    Full Text Available Background: In this study, we investigated the lethal potency, electrophoretic protein pattern and in vivo effects of Hottentotta saulcyi scorpion venom in mice.Methods: Scorpions were collected at night, by using a UV lamp from Mardin Province, Turkey. Venom was obtained from mature H. saulcyi scorpions by electrical stimulation of the telson. The lethality of the venom was determined by i.v. injections using Swiss mice. In vivo effects of the venom were assessed by using the intraperitoneal route (ip injections into mice (20±1g and monitored for 24 h. The protein profiles of the scorpion venom were analyzed by NuPAGE® Novex® 4–12 % gradient Bis-Tris gel followed by Coomassie blue staining.Results: The lethal assay of the venom was 0.73 mg/kg in mice. We determined the electrophoretic protein pattern of this scorpion venom to be 4, 6, 9, 31, 35, 40, 46 and 69 kDa by SDS-PAGE. Analysis of electrophoresis indicated that H. saulcyi scorpion intoxicated mice exhibited autonomic nervous system symptoms (tachypnea, restlessness, hyperexcitability, convulsions, salivation, lacrimation, weakness.Conclusions: Hottentotta saulcyi scorpion venom includes short-chain neurotoxins and long-chain neurotoxins according to the electrophoretic protein patterns. The stings of H. saulcyi scorpion must be considered of risk for humans in the southeastern region, Turkey.

  11. Proceedings for the nondestructive assay and nondestructive examination waste characterization conference. No. 5

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    This report contains paper presented at the 5th Nondestructive Assay and nondestructive Examination Waste Characterization conference. Topics included compliance, neutron NDA techniques, gamma NDA techniques, tomographic methods, and NDA modality and information combination techniques. Individual reports have been processed separately for the United States Department of Energy databases.

  12. Proceedings for the nondestructive assay and nondestructive examination waste characterization conference. No. 5

    International Nuclear Information System (INIS)

    1997-01-01

    This report contains paper presented at the 5th Nondestructive Assay and nondestructive Examination Waste Characterization conference. Topics included compliance, neutron NDA techniques, gamma NDA techniques, tomographic methods, and NDA modality and information combination techniques. Individual reports have been processed separately for the United States Department of Energy databases

  13. Non-destructive analysis of spent nuclear fuel

    International Nuclear Information System (INIS)

    Popovic, D.

    1961-12-01

    Nondestructive analysis of fuel elements dealt with determining the isotope contents which provide information about the burnup level, quantities of fission products and neutron-multiplication properties of the irradiated fuel. Methods for determination of the isotope ratio of the spent fuel are both numerical and experimental. This report deals with the experimental method. This means development of the experimental methods for direct measurement of the isotope content. A number of procedures are described: measurements of α, β and γ activities of the isotopes; measurement of secondary effects of nuclear reactions with thermal neutrons and fast neutrons; measurement of cross sections; detection of prompt and delayed neutrons

  14. Nondestructive radioassay for waste management: an assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lehmkuhl, G.D.

    1981-06-01

    Nondestructive Assay (NDA) for Transuranic Waste Management is used to mean determining the amount of transuranic (TRU) isotopes in crates, drums, boxes, cans, or other containers without having to open the container. It also means determining the amount of TRU in soil, bore holes, and other environmental testing areas without having to go through extensive laboratory wet chemistry analyses. it refers to radioassay techniques used to check for contamination on objects after decontamination and to determine amounts of TRU in waste processing streams without taking samples to a laboratory. Gednerally, NDA instrumentation in this context refers to all use of radioassay which does not involve taking samples and using wet chemistry techniques. NDA instruments have been used for waste assay at some sites for over 10 years and other sites are just beginning to consider assay of wastes. The instrumentation used at several sites is discussed in this report. Almost all these instruments in use today were developed for special nuclear materials safeguards purposes and assay TRU waste down to the 500 nCi/g range. The need for instruments to assay alpha particle emitters at 10 nCi/g or less has risen from the wish to distinguish between Low Level Waste (LLW) and TRU Waste at the defined interface of 10 nCi/g. Wastes have historically been handled as TRU wastes if they were just suspected to be transuranically contaminated but their exact status was unknown. Economic and political considerations make this practice undesirable since it is easier and less costly to handle LLW. This prompted waste generators to want better instrumentation and led the Transuranic Waste Management Program to develop and test instrumentation capable of assaying many types of waste at the 10 nCi/g level. These instruments are discussed.

  15. 210Po- and 210Pb- determination in Hungarian tobacco leaves and dose assessment

    International Nuclear Information System (INIS)

    Kovacs, T.; Bodrogi, E.; Somlai, J.; Baranyi, A.; Dombovari, P.

    2003-01-01

    Because the tobacco of the cigarettes sold in Hungary are domestically grown; the aim of our investigations was to determine the concentrations of 210 Po and 210 Pb in the tobacco plants coming from the different areas of Hungary. Additionally, soil samples and phosphor fertilisers as the potential sources of these radionuclides were also investigated. Special attention was given to the tobacco grown at a tailing pond of a former uranium mine under remediation and the plants grown nearby. One of the biggest tobacco plants is situated there. The 210 Po and 210 Pb concentrations of the investigated tobaccos and cigarettes do not differ considerably, so during the cigarette making process the concentration of these radionuclides does not change to a great extent. The 210 Po concentrations of the phosphate fertilizers available in Hungary were not found extremely high in either case. The ( 210 Po 72-1498 mBq/g, 210 Pb 313-985 mBq/g) concentrations of the tobacco grown at the experiment plant situated at a former uranium mine (waste hip) were high, as expected. This territory is not available for agricultural purposes. Our results also indicate that it is reasonable. The samples from the totally covered (re-mediated) tailing pond are under investigation. (authors)

  16. The dose distribution determination in two kinds of polyethylene materials irradiated by electron beams-an experimental method for optimizing technology of radiation processing

    International Nuclear Information System (INIS)

    Zhang Daming

    2000-01-01

    The dose distribution in two kinds of polyethylene materials were determined by use of electron beam from 1.0-3.0 MeV electron accelerator. The effects of four different metal base-plate such as Al, Fe, Cu and Pb for dose depth distribution in materials were compared. And the boundary effects of absorbed dose were also observed. The expand uncertainty of absorbed dose measurement was 7.8%. This work is a useful experimental method for optimizing technology of radiation processing and realizing quality control of irradiation products

  17. Determination of the minimum protective dose for bluetongue virus serotype 2 and 8 vaccines in sheep.

    Science.gov (United States)

    Modumo, Jacob; Venter, Estelle H

    2012-08-03

    Recent outbreaks of bluetongue virus (BTV) serotypes 2 and 8 in many European countries provided an opportunity to investigate the possibility of improving the safety of the modified live vaccines administered mainly in South Africa. Modified live vaccines (MLV) released at a titre of 5 x 104 PFU/mL, raised concerns and prompted the need to determine the minimum titre which will still be protective and also safe. The BTV serotypes 2 and 8 vaccines were produced at the following titres: 102 PFU/mL, 103 PFU/mL and 104 PFU/mL, and were injected into 24 sheep which were then monitored. Blood was collected on days 0, 3, 6, 9, 12, 15, 18, 21, 25, 28 and 4 months post vaccination, for seroconversion and viraemia studies. These sheep were later challenged at 4 months post vaccination using BTV infected cell culture material, they were then observed and bled and again tested for viraemia. There was no viraemia post vaccination, however, a febrile reaction did occur and seroconversion was demonstrated at low titres for both BTV 2 and 8. Although viraemia was demonstrated post challenge, sheep vaccinated with the low titre BTV 2 vaccine showed more than a 90% protection index at a lower titre of 103 PFU/mL, compared with BTV 8 that showed a protection index above 90% at all the titres used. It is recommended that for BTV 2 vaccine, sheep should be vaccinated at a titre of 103 PFU/mL and at a titre of 102 PFU/mL with BTV 8 vaccine.

  18. Determination of the minimum protective dose for bluetongue virus serotype 2 and 8 vaccines in sheep

    Directory of Open Access Journals (Sweden)

    Jacob Modumo

    2012-08-01

    Full Text Available Recent outbreaks of bluetongue virus (BTV serotypes 2 and 8 in many European countries provided an opportunity to investigate the possibility of improving the safety of the modified live vaccines administered mainly in South Africa. Modified live vaccines (MLV released at a titre of 5 x 104 PFU/mL, raised concerns and prompted the need to determine the minimum titre which will still be protective and also safe. The BTV serotypes 2 and 8 vaccines were produced at the following titres: 102 PFU/mL, 103 PFU/mL and 104 PFU/mL, and were injected into 24 sheep which were then monitored. Blood was collected on days 0, 3, 6, 9, 12, 15, 18, 21, 25, 28 and 4 months post vaccination, for seroconversion and viraemia studies. These sheep were later challenged at 4 months post vaccination using BTV infected cell culture material, they were then observed and bled and again tested for viraemia. There was no viraemia post vaccination, however, a febrile reaction did occur and seroconversion was demonstrated at low titres for both BTV 2 and 8. Although viraemia was demonstrated post challenge, sheep vaccinated with the low titre BTV 2 vaccine showed more than a 90% protection index at a lower titre of 103 PFU/mL, compared with BTV 8 that showed a protection index above 90% at all the titres used. It is recommended that for BTV 2 vaccine, sheep should be vaccinated at a titre of 103 PFU/mL and at a titre of 102 PFU/mL with BTV 8 vaccine.

  19. Effect of improved TLD dosimetry on the determination of dose rate constants for 125I and 103Pd brachytherapy seeds

    International Nuclear Information System (INIS)

    Rodriguez, M.; Rogers, D. W. O.

    2014-01-01

    Purpose: To more accurately account for the relative intrinsic energy dependence and relative absorbed-dose energy dependence of TLDs when used to measure dose rate constants (DRCs) for 125 I and 103 Pd brachytherapy seeds, to thereby establish revised “measured values” for all seeds and compare the revised values with Monte Carlo and consensus values. Methods: The relative absorbed-dose energy dependence, f rel , for TLDs and the phantom correction, P phant , are calculated for 125 I and 103 Pd seeds using the EGSnrc BrachyDose and DOSXYZnrc codes. The original energy dependence and phantom corrections applied to DRC measurements are replaced by calculated (f rel ) −1 and P phant values for 24 different seed models. By comparing the modified measured DRCs to the MC values, an appropriate relative intrinsic energy dependence, k bq rel , is determined. The new P phant values and relative absorbed-dose sensitivities, S AD rel , calculated as the product of (f rel ) −1 and (k bq rel ) −1 , are used to individually revise the measured DRCs for comparison with Monte Carlo calculated values and TG-43U1 or TG-43U1S1 consensus values. Results: In general, f rel is sensitive to the energy spectra and models of the brachytherapy seeds. Values may vary up to 8.4% among 125 I and 103 Pd seed models and common TLD shapes. P phant values depend primarily on the isotope used. Deduced (k bq rel ) −1 values are 1.074 ± 0.015 and 1.084 ± 0.026 for 125 I and 103 Pd seeds, respectively. For (1 mm) 3 chips, this implies an overall absorbed-dose sensitivity relative to 60 Co or 6 MV calibrations of 1.51 ± 1% and 1.47 ± 2% for 125 I and 103 Pd seeds, respectively, as opposed to the widely used value of 1.41. Values of P phant calculated here have much lower statistical uncertainties than literature values, but systematic uncertainties from density and composition uncertainties are significant. Using these revised values with the literature’s DRC measurements, the

  20. In vivo dosimetry using a linear Mosfet-array dosimeter to determine the urethra dose in 125I permanent prostate implants.

    Science.gov (United States)

    Bloemen-van Gurp, Esther J; Murrer, Lars H P; Haanstra, Björk K C; van Gils, Francis C J M; Dekker, Andre L A J; Mijnheer, Ben J; Lambin, Philippe

    2009-01-01

    In vivo dosimetry during brachytherapy of the prostate with (125)I seeds is challenging because of the high dose gradients and low photon energies involved. We present the results of a study using metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters to evaluate the dose in the urethra after a permanent prostate implantation procedure. Phantom measurements were made to validate the measurement technique, determine the measurement accuracy, and define action levels for clinical measurements. Patient measurements were performed with a MOSFET array in the urinary catheter immediately after the implantation procedure. A CT scan was performed, and dose values, calculated by the treatment planning system, were compared to in vivo dose values measured with MOSFET dosimeters. Corrections for temperature dependence of the MOSFET array response and photon attenuation in the catheter on the in vivo dose values are necessary. The overall uncertainty in the measurement procedure, determined in a simulation experiment, is 8.0% (1 SD). In vivo dose values were obtained for 17 patients. In the high-dose region (> 100 Gy), calculated and measured dose values agreed within 1.7% +/- 10.7% (1 SD). In the low-dose region outside the prostate (MOSFET detectors are suitable for in vivo dosimetry during (125)I brachytherapy of prostate cancer. An action level of +/- 16% (2 SD) for detection of errors in the implantation procedure is achievable after validation of the detector system and measurement conditions.

  1. Development of a methodology to determine optimized therapeutic doses of {sup 131}I for the treatment of hyperthyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, F.; Moura, M.B.; Pereira, A.C., E-mail: faraujo@ird.gov.br [Instituto de Medicna Nuclear (IMEN), Goiania, GO (Brazil); Dantas, B.M.; Dantas, A.L.A.; Lucena, E.A. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Melo, R.C.; Rebelo, A.M.O. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Faculdade de Medicina

    2008-07-01

    Several methods can be used to determine the activity of {sup 131}I to be administered for the treatment of hyperthyroidism. However, some of them do not take into consideration the dose absorbed by the thyroid, while others do not consider all the parameters necessary for dose calculation. The relationship between the dose absorbed by the thyroid and the activity administered depends basically on three parameters: mass of the organ, iodine uptake and effective half-life of iodine in the thyroid. Such parameters should be individually determined for each patient in order to optimize the administered activity. The objective of this work is to develop a methodology for individualized treatment with {sup 131}I in patients with hyperthyroidism of the Grave's Disease. A neck-thyroid phantom developed at the In Vivo Monitoring Laboratory of IRD, containing a known amount of {sup 131}I, was used to calibrate a scintillation camera and a uptake probe available at the Nuclear Medicine Center of the University Hospital of Rio de Janeiro and Instituto de Medicina Nuclear - IMEN, of Goiania. The optimization of the counting geometry was carried out by the determination of the characteristic curves of the view angle of the collimator-detector assembly. The view angle of the collimator-detector assembly presented values compatible with the size of the organ for distances of 25 cm (uptake probe) and 45.8 cm (scintillation camera). The calibration factors (in cpm/kBq) and the associated uncertainty related to these distances were (39.3 ± 0.78), (58.1 ± 2.38) to uptake probe SCT-13004 e 13002, respectively and 4.3 ± 0.17 to scintillation camera. The time period between 14 and 30 hours of the retention curve allows the calculation of the activity between those two points. It is concluded that the use of diagnose equipment available at the hospital (scintillation camera and uptake probe) has shown to be a suitable procedure in terms of effectiveness, simplicity and cost

  2. Development of a methodology to determine optimized therapeutic doses of 131I for the treatment of hyperthyroidism

    International Nuclear Information System (INIS)

    Araujo, F.; Moura, M.B.; Pereira, A.C.; Dantas, B.M.; Dantas, A.L.A.; Lucena, E.A.; Melo, R.C.; Rebelo, A.M.O.

    2008-01-01

    Several methods can be used to determine the activity of 131 I to be administered for the treatment of hyperthyroidism. However, some of them do not take into consideration the dose absorbed by the thyroid, while others do not consider all the parameters necessary for dose calculation. The relationship between the dose absorbed by the thyroid and the activity administered depends basically on three parameters: mass of the organ, iodine uptake and effective half-life of iodine in the thyroid. Such parameters should be individually determined for each patient in order to optimize the administered activity. The objective of this work is to develop a methodology for individualized treatment with 131 I in patients with hyperthyroidism of the Grave's Disease. A neck-thyroid phantom developed at the In Vivo Monitoring Laboratory of IRD, containing a known amount of 131 I, was used to calibrate a scintillation camera and a uptake probe available at the Nuclear Medicine Center of the University Hospital of Rio de Janeiro and Instituto de Medicina Nuclear - IMEN, of Goiania. The optimization of the counting geometry was carried out by the determination of the characteristic curves of the view angle of the collimator-detector assembly. The view angle of the collimator-detector assembly presented values compatible with the size of the organ for distances of 25 cm (uptake probe) and 45.8 cm (scintillation camera). The calibration factors (in cpm/kBq) and the associated uncertainty related to these distances were (39.3 ± 0.78), (58.1 ± 2.38) to uptake probe SCT-13004 e 13002, respectively and 4.3 ± 0.17 to scintillation camera. The time period between 14 and 30 hours of the retention curve allows the calculation of the activity between those two points. It is concluded that the use of diagnose equipment available at the hospital (scintillation camera and uptake probe) has shown to be a suitable procedure in terms of effectiveness, simplicity and cost. (author)

  3. Investigating physiological methods to determine previous exposure of immature insects to ionizing radiation and estimating the exposure dose

    International Nuclear Information System (INIS)

    Mansour, M.

    1998-10-01

    Effects of gamma radiation on pupation and adult emergence in mature (diapausing and non-diapausing) codling moth, Cydia pomonella L., larvae and on phenoloxidase activity in larvae killed by freezing were investigated. Results showed that, a dose of 50 Gy reduced adult emergence (and pupation) significantly and 200 Gy completely prevented it. Diapausing larvae were more susceptible to irradiation that non-diapausing larvae and female moths were more susceptible to irradiation injury than males. Phenoloxidase activity in codling moth larvae was determined spectrophotometrically by measuring the increase in optical density at 490 nm, or by observing the degree of melanization in larvae killed by freezing. Results showed that, in un-irradiated larvae, phenoloxidase activity can be detected in 7 day old larvae and activity continued to accumulate throughout the larval stage. This accumulation was not observed when larvae were irradiated with a minimum dose of 50 Gy during the 1st week of their development. However, irradiating larvae in which enzyme activity was already high (2-3 week old) did not remove activity but only reduced further accumulation. Larval melanization studies were in agreement with results of the phenoloxidase assay. (author)

  4. Non-radioactive determination of the penetration of methyl iodide through impregnated charcoals during dosing and purging

    International Nuclear Information System (INIS)

    Romans, J.B.; Deitz, V.R.

    1979-01-01

    A laboratory procedure is described using methyl iodide-127 which had the same linear flow of air (12.2 m/min) and contact time (0.25 sec.) as the RDT M16 Test Procedure. Only one-fourth of the charcoal was used (in a bed 2.54 cm diameter and 5.08 cm high) and the required dose of methyl iodide-127 was reduced from 5.25 to 1.31 mg. The inlet concentrations were determined with a gas chromatograph and the effluent concentrations with a modified microcoulombmeter. Two calibration procedures were used: (1) known vapor pressure of iodine crystals, and (2) quantitative pyrolysis of the methyl iodide-127 delivered from certified permeation tubes. Five charcoals and three impregnations were used in this study. Typical behaviors are given in 90% RH air with the charcoals either prehumidified for 16 hours at 90% RH or without the prehumidification. The breakthrough curves, concentration versus time, rose very slowly for the first 120 minutes and then more rapidly for an additional time. The lack of a dependence on the magnitude of the dose is compatible with a catalytic trapping mechanism. In the case of KI/sub x/ impregnations, there was excess emission of iodine during purging over that introduced as methyl iodide-127 which must have originated in the reservoir of iodine contained in the impregnation

  5. Nondestructive quality evaluation technology of agricultural products

    International Nuclear Information System (INIS)

    Noh, Sang Ha

    1997-01-01

    Quality evaluation of agricultural products has been interested to many researchers for many years and as the result, several nondestructive techniques and so many papers have been reported for quality evaluation of agricultural products. These nondestructive techniques are based on the detection of mechanical, optical, electrical, electro-magnetical, dielectric and vibrational properties of agricultural products that are well correlated with certain quality factors of the products such as color, shape, firmness, sugar content, external or internal defects, moisture content, etc. The sophistication of nondestructive methods has evolved rapidly with modem technologies. In this paper an emphasis was put on reviewing some of those papers and techniques which could be led to on-line measurement for practical use.

  6. Determination of "2"1"0Po in calcium supplements and the possible related dose assessment to the consumers

    International Nuclear Information System (INIS)

    Strumińska-Parulska, Dagmara I.

    2015-01-01

    The aim of this pioneer study was to investigate the most popular calcium supplements as a potential additional source of polonium "2"1"0Po in human diet. The analyzed calcium pharmaceutics contained organic or inorganic calcium compounds; some from natural sources as mussels' shells, fish extracts, or sedimentary rocks. The objectives of this research were to investigate the naturally occurring "2"1"0Po activity concentrations in calcium supplements, find the correlations between "2"1"0Po concentration in medicament and calcium chemical form, and calculate the effective radiation dose connected to analyzed calcium supplement consumption. As results showed, "2"1"0Po concentrations in natural origin calcium supplements (especially sedimentary rocks) were higher than the other analyzed. Also the results of "2"1"0Po analysis obtained for inorganic forms of calcium supplements were higher. The highest "2"1"0Po activity concentrations were determined in mineral tablets made from sedimentary rocks: dolomite and chalk – 3.88 ± 0.22 and 3.36 ± 0.10 mBq g"−"1 respectively; while the lowest in organic calcium compounds: calcium lactate and calcium gluconate – 0.07 ± 0.02 and 0.17 ± 0.01 mBq g"−"1. The annual effective radiation doses from supplements intake were estimated as well. The highest annual radiation dose from "2"1"0Po taken with 1 tablet of calcium supplement per day was connected to sample made from chalk – 2.5 ± 0.07 μSv year"−"1, while the highest annual radiation dose from "2"1"0Po taken with 1 g of pure calcium per day was connected to dolomite – 12.7 ± 0.70 μSv year"−"1. - Highlights: • "2"1"0Po in the most popular calcium supplements in Poland was investigated. • "2"1"0Po is present in calcium supplements and could be an additional source of "2"1"0Po for human. • Inorganic samples were richer in "2"1"0Po in comparison to organic. • Additives from sedimentary rocks, were richer in polonium in comparison to

  7. Uncertainty analysis in the determination of absorbed dose in water by Fricke chemical dosimetry; Analise das incertezas na determinacao da dose absorvida na agua por dosimetria quimica Fricke

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Fabia; Aguirre, Eder Aguirre, E-mail: fabiavasco@hotmail.com, E-mail: ederuni01@gmail.com [Fundacao do Cancer, Rio de Janeiro, RJ (Brazil); Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)

    2016-07-01

    This work studies the calculations of uncertainties and the level of confidence that involves the process for obtaining the dose absorbed in water using the method of Fricke dosimetry, developed at Laboratorio de Ciencias Radiologicas (LCR). Measurements of absorbance of samples Fricke, irradiated and non-irradiated is going to use in order to calculate the respective sensitivity coefficients, along with the expressions of the calculation of Fricke dose and the absorbed dose in water. Those expressions are used for calculating the others sensitivity coefficients from the input variable. It is going to use the combined uncertainty and the expanded uncertainty, with a level of confidence of 95.45%, in order to report the uncertainties of the measurement. (author)

  8. Determination of gamma radiation dose as a post-harvest treatment in mangos infested with the South American fruit fly

    International Nuclear Information System (INIS)

    Alama, D.

    1999-01-01

    Efforts are being made to determine a gamma radiation dose for mortality of third-instar larvae of Anastrepha fraterculus which infest mangos of the Haden variety of 400 g weight. Four radiation treatments were tested: 0.4 kGy, 0.6 kGy, 0.8 kGy and 1.0 kGy. Using as a criterium for mortality the interruption of the biological cycle between larva and pupa, the following results were achieved: 49.61%, 63.33%, 74.86% and 90.72%. The percentages obtained have been corrected using the Abbot formula. When the criterium was based on no adult emergence, 100% mortality was achieved for the four treatments. (author)

  9. Non-destructive testing. V. 2

    International Nuclear Information System (INIS)

    Farley, J.M.; Nichols, R.W.

    1988-01-01

    The book entitled 'Non-destructive Testing' Volume 2, contains the proceedings of the fourth European Conference, organized by the British Institute of Non-Destructive Testing and held in London, September 1987. The volume contains seven chapters which examine the reliability of NDT, the economics of NDT and the use of NDT in:- civil engineering; oil, gas, coal and petrochemical industries; iron and steel industries; aerospace industry; and the nuclear and electricity supply industries. The seven chapters contain 78 papers, of which 19 are selected for INIS and indexed separately. (U.K.)

  10. Non-destructive testing of electronic parts

    International Nuclear Information System (INIS)

    Widenhorn, G.

    1980-01-01

    The requirements on quality, safety, faultlessness and reliability of electric components increase because of the high complexity of the appliances in which they are used. By means of examples a survey is given on the common non-destructive testing methods, testing operation and evaluation of test results on electric components which must meet in their application high requirements on quality and reliability. Defective components, especially those with hidden failures are sorted out by non-destructive testing and the failure frequency of the appliances and plants in testing and operation is greatly reduced. (orig.) [de

  11. Nondestructive characterization of austenitic stainless steels

    International Nuclear Information System (INIS)

    Jayakumar, T.; Kumar, Anish

    2010-01-01

    The paper presents an overview of the non-destructive methodologies developed at the authors' laboratory for characterization of various microstructural features, residual stresses and corrosion in austenitic stainless steels. Various non-destructive evaluation (NDE) parameters such as ultrasonic velocity, ultrasonic attenuation, spectral analysis of the ultrasonic signals, magnetic hysteresis parameters and eddy current amplitude have been used for characterization of grain size, precipitation behaviour, texture, recrystallization, thermomechanical processing, degree of sensitization, formation of martensite from metastable austenite, assessment of residual stresses, degree of sensitization and propensity for intergranular corrosion in different austenitic steels. (author)

  12. Nondestructive analysis of the gold quarter liras

    International Nuclear Information System (INIS)

    Cakir, C.; Guerol, A.; Demir, L.; Sahin, Y.

    2009-01-01

    In this study, we have prepared seven Au-Cu standards in the concentration range of 18-24 (as carat) for nondestructive control of gold quarter liras. Some calibration curves for quantitative analysis of Au in the gold quarter liras that commercially present in Turkey have been plotted using these standard samples. The characteristic X-rays of Au and Cu emitted from these standard samples and the test sample with known composition are recorded by using a Ge(Li) detector. These calibration curves provide a nondestructive analysis of gold quarter liras with the uncertainties about 1.18%. (author)

  13. Cost-risk optimization of nondestructive inspection level

    International Nuclear Information System (INIS)

    Johnson, D.P.

    1978-01-01

    This paper develops a quantitative methodology for determining the nondestructive inspection (NDI) level that will result in a minimum cost product considering both type one inspection errors, acceptance of defective material units, and type two inspection errors, rejection of sound material units. This methodology represents an advance over fracture mechanics - nondestructive inspection (FM-NDI) design systems that do not consider type two inspection errors or the pre-inspection material quality. The inputs required for the methodology developed in this paper are (1) the rejection probability as a function of inspection size and imperfection size, (2) the flaw frequency (FF), as a function of imperfection size, (3) the probability of failure given the material unit contains an imperfection of a given size as a function of that given size, (4) the manufacturing cost per material unit, (5) the inspection cost per material unit, and (6) the average cost per failure including indirect costs. Four methods are identified for determining the flaw-frequency and three methods are identified for determining the conditional failure probability (one of these methods is probabilistic fracture mechanics). Methods for determining the rejection probability are discussed elsewhere. The NDI-FF methodology can have significant impact where the cost of failures represents a significant fraction of the manufacturing costs, or when a significant fraction of the components are being rejected by the inspection. (Auth.)

  14. Attributes identification of nuclear material by non-destructive radiation measurement methods

    International Nuclear Information System (INIS)

    Gan Lin

    2002-01-01

    Full text: The nuclear materials should be controlled under the regulation of National Safeguard System. The non-destructive analysis method, which is simple and quick, provide a effective process in determining the nuclear materials, nuclear scraps and wastes. The method play a very important role in the fields of nuclear material control and physical protection against the illegal removal and smuggling of nuclear material. The application of non-destructive analysis in attributes identification of nuclear material is briefly described in this paper. The attributes determined by radioactive detection technique are useful tolls to identify the characterization of special nuclear material (isotopic composition, enrichment etc.). (author)

  15. Nondestructive Examination Guidance for Dry Storage Casks

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Ryan M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suffield, Sarah R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hirt, Evelyn H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suter, Jonathan D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lareau, John P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhuge, Jing Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qiao, Hong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moran, Traci L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-30

    In this report, an assessment of NDE methods is performed for components of NUHOMS 80 and 102 dry storage system components in an effort to assist NRC staff with review of license renewal applications. The report considers concrete components associated with the horizontal storage modules (HSMs) as well as metal components in the HSMs. In addition, the report considers the dry shielded canister (DSC). Scope is limited to NDE methods that are considered most likely to be proposed by licensees. The document, ACI 349.3R, Evaluation of Existing Nuclear Safety-Related Concrete Structures, is used as the basis for the majority of the NDE methods summarized for inspecting HSM concrete components. Two other documents, ACI 228.2R, Nondestructive Test Methods for Evaluation of Concrete in Structures, and ORNL/TM-2007/191, Inspection of Nuclear Power Plant Structure--Overview of Methods and Related Application, supplement the list with additional technologies that are considered applicable. For the canister, the ASME B&PV Code is used as the basis for NDE methods considered, along with currently funded efforts through industry (Electric Power Research Institute [EPRI]) and the U.S. Department of Energy (DOE) to develop inspection technologies for canisters. The report provides a description of HSM and DSC components with a focus on those aspects of design considered relevant to inspection. This is followed by a brief description of other concrete structural components such as bridge decks, dams, and reactor containment structures in an effort to facilitate comparison between these structures and HSM concrete components and infer which NDE methods may work best for certain HSM concrete components based on experience with these other structures. Brief overviews of the NDE methods are provided with a focus on issues and influencing factors that may impact implementation or performance. An analysis is performed to determine which NDE methods are most applicable to specific

  16. Non-destructive decontamination of building materials

    Science.gov (United States)

    Holecek, Josef; Otahal, Petr

    2015-11-01

    For nondestructive radiation decontamination of surfaces it is necessary to use varnishes, such as ARGONNE, DG1101, DG1108, etc. This text evaluates the use of manufactured strippable coatings for radiation decontamination. To evaluate decontamination capability of such coatings the following varnishes were selected and subsequently used: AZ 1-700 and AXAL 1807S. The varnishes were tested on different building materials surfaces contaminated by short-term radioisotopes of Na-24 or La-140, in water soluble or water insoluble forms. Decontamination quality was assessed by the decontamination efficiency value, defined as the proportion of removed activity to the applied activity. It was found that decontamination efficiency of both used varnishes depends not only on the form of contaminant, but in the case of application of AXAL 1807S varnish it also depends on the method of its application on the contaminated surface. The values of the decontamination efficiency for AZ1-700 varnish range from 46% for decontamination of a soluble form of the radioisotope from concrete surface to 98% for the decontamination of a soluble form of the radioisotope from ceramic tile surface. The decontamination efficiency values determined for AXAL 1807S varnish range from 48% for decontamination of a soluble form of the radioisotope from concrete surface to 96% for decontamination of an insoluble form of the radioisotope from ceramic tile surface. Comparing these values to the values given for the decontaminating varnishes we can conclude that AXAL 1807S varnish is possible to use on all materials, except highly porous materials, such as plasterboard or breeze blocks, or plastic materials. AZ 1-700 varnish can be used for all dry materials except plasterboard.

  17. Derivation, evidence and physical validity of a weighted beam-zone method for dose determination in blocked photon fields of arbitrary shape

    International Nuclear Information System (INIS)

    Glaeser, L.; Quast, U.

    1981-01-01

    A simple, practical procedure for dose determination at any point of an arbitrarily shaped field has been derived: Square-field photon beams are sectioned into a set of pyramid-shell-like parts (beam zones), nested into each other around the smallest realizable square field, of different sizes but with equal dose contributions (thus weighted) with respect to a central dose reference point. The dose at any reference point in an irregular field can be determined simply by counting the number of non-shielded dose-contributing zones (or zone fractions), leading to the associated order of square-field size (with the same number of zones), the equivalent field with known dose. For experimental evidence of the validity of the weighted beam-zone method, measurements were carried out with different high-energy photon beams with one or more beam zones shielded by absorbing blocks. Measurements were made at points in unshielded and shielded parts of the field, on and off the beam axis and at different depths in a phantom. Calculations and measurements were compared. While relative depth doses were shown to be equal to within +-2% over a range of 5 cm ahead of and behind the dose reference point, the absolute dose deviations were within +-4%. The sources of error were analysed. They were mainly determined by scattered radiation from the beam limiting device and the partial shielding deriving from the shielding blocks. The same errors also occur in most of the known methods of dose calculation in irregular fields. (author)

  18. Determinants of antibody persistence across doses and continents after single-dose rVSV-ZEBOV vaccination for Ebola virus disease: an observational cohort study.

    Science.gov (United States)

    Huttner, Angela; Agnandji, Selidji Todagbe; Combescure, Christophe; Fernandes, José F; Bache, Emmanuel Bache; Kabwende, Lumeka; Ndungu, Francis Maina; Brosnahan, Jessica; Monath, Thomas P; Lemaître, Barbara; Grillet, Stéphane; Botto, Miriam; Engler, Olivier; Portmann, Jasmine; Siegrist, Denise; Bejon, Philip; Silvera, Peter; Kremsner, Peter; Siegrist, Claire-Anne

    2018-04-04

    The recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire Ebola virus (ZEBOV) glycoprotein is efficacious in the weeks following single-dose injection, but duration of immunity is unknown. We aimed to assess antibody persistence at 1 and 2 years in volunteers who received single-dose rVSV-ZEBOV in three previous trials. In this observational cohort study, we prospectively followed-up participants from the African and European phase 1 rVSV-ZEBOV trials, who were vaccinated once in 2014-15 with 300 000 (low dose) or 10-50 million (high dose) plaque-forming units (pfu) of rVSV-ZEBOV vaccine to assess ZEBOV glycoprotein (IgG) antibody persistence. The primary outcome was ZEBOV glycoprotein-specific IgG geometric mean concentrations (GMCs) measured yearly by ELISA compared with 1 month (ie, 28 days) after immunisation. We report GMCs up to 2 years (Geneva, Switzerland, including neutralising antibodies up to 6 months) and 1 year (Lambaréné, Gabon; Kilifi, Kenya) after vaccination and factors associated with higher antibody persistence beyond 6 months, according to multivariable analyses. Trials and the observational study were registered at ClinicalTrials.gov (Geneva: NCT02287480 and NCT02933931; Kilifi: NCT02296983) and the Pan-African Clinical Trials Registry (Lambaréné PACTR201411000919191). Of 217 vaccinees from the original studies (102 from the Geneva study, 75 from the Lambaréné study, and 40 from the Kilifi study), 197 returned and provided samples at 1 year (95 from the Geneva study, 63 from the Lambaréné, and 39 from the Kilifi study) and 90 at 2 years (all from the Geneva study). In the Geneva group, 44 (100%) of 44 participants who had been given a high dose (ie, 10-50 million pfu) of vaccine and who were seropositive at day 28 remained seropositive at 2 years, whereas 33 (89%) of 37 who had been given the low dose (ie, 300 000 pfu) remained seropositive for 2 years (p=0·042). In participants who had received a high dose

  19. The use of Fricke dosimeter to determine the absorbed dose from brachytherapy equipment in the Northeastern Brazil

    International Nuclear Information System (INIS)

    Souza, Vivianne Lucia B.; Cunha, Manuela S.; Figueiredo, Marcela D.C.; Santos, Carla D.A.; Rodrigues, Kelia R.G.; Lira, Gabriela B.S.; Silva, Danubia B.; Melo, Roberto T.

    2011-01-01

    This paper describes the practical results of an assessment of the situation of brachytherapy services throughout the Northeast. A Fricke dosimetry system capable of verifying the dose absorbed in water, prepared by researchers from the Regional Center of Nuclear Sciences was brought to public hospitals in the Northeast. The system not only evaluates if the applied (measured) dose is close to the calculated (prescribed) dose, but is also capable of verifying human errors and/or mechanical or the International Atomic Energy Agency (IAEA) standards regarding the percentage of allowed difference between the prescribed dose and dose measurement. (author)

  20. Determination of uncertainties in the calculation of dose rates at transport and storage casks; Unsicherheiten bei der Berechnung von Dosisleistungen an Transport- und Lagerbehaeltern

    Energy Technology Data Exchange (ETDEWEB)

    Schloemer, Luc Laurent Alexander

    2014-12-17

    The compliance with the dose rate limits for transport and storage casks (TLB) for spent nuclear fuel from pressurised water reactors can be proved by calculation. This includes the determination of the radioactive sources and the shielding-capability of the cask. In this thesis the entire computational chain, which extends from the determination of the source terms to the final Monte-Carlo-transport-calculation is analysed and the arising uncertainties are quantified not only by benchmarks but also by variational calculi. The background of these analyses is that the comparison with measured dose rates at different TLBs shows an overestimation by the values calculated. Regarding the studies performed, the overestimation can be mainly explained by the detector characteristics for the measurement of the neutron dose rate and additionally in case of the gamma dose rates by the energy group structure, which the calculation is based on. It turns out that the consideration of the uncertainties occurring along the computational chain can lead to even greater overestimation. Concerning the dose rate calculation at cask loadings with spent uranium fuel assemblies an uncertainty of (({sup +21}{sub -28}) ±2) % (rel.) for the total gamma dose rate and of ({sup +28±23}{sub -55±4}) % (rel.) for the total neutron dose rate are estimated. For mixed-loadings with spent uranium and MOX fuel assemblies an uncertainty of ({sup +24±3}{sub -27±2}) % (rel.) for the total gamma dose rate and of ({sup +28±23}{sub -55±4}) % (rel.) for the total neutron dose rate are quantified. The results show that the computational chain has not to be modified, because the calculations performed lead to conservative dose rate predictions, even if high uncertainties at neutron dose rate measurements arise. Thus at first the uncertainties of the neutron dose rate measurement have to be decreased to enable a reduction of the overestimation of the calculated dose rate afterwards. In the present thesis