Read by QxMD icon Read

Applied Radiation and Isotopes

M S Dias, R Semmler, D S Moreira, M O de Menezes, L F Barros, R V Ribeiro, M F Koskinas
The main features of code SUMCOR developed for cascade summing correction for volumetric sources are described. MCNP6 is used to track histories starting from individual points inside the volumetric source, for each set of cascade transitions from the radionuclide. Total and FEP efficiencies are calculated for all gamma-rays and X-rays involved in the cascade. Cascade summing correction is based on the matrix formalism developed by Semkow et al. (1990). Results are presented applying the experimental data sent to the participants of two intercomparisons organized by the ICRM-GSWG and coordinated by Dr...
September 14, 2017: Applied Radiation and Isotopes
I M Yamazaki, M F Koskinas, D S Moreira, M N Takeda, M S Dias
The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN for the standardization of activity of (64)Cu is described. The measurement was carried out in a 4π (PC) β-γ coincidence system. The activity per unit mass of the solution was determined by the extrapolation technique. The events were registered using a Time to Amplitude Converter (TAC) associated with a Multi-channel Analyzer. The gamma-ray emission probability per decay of the 1345.7keV transition of (64)Cu determined with a calibrated REGe gamma-ray spectrometer was (0...
September 9, 2017: Applied Radiation and Isotopes
M Ajijul Hoq, M A Malek Soner, M A Salam, M M Haque, Salma Khanom, S M Fahad
The 3MW TRIGA Mark-II Research Reactor of Bangladesh Atomic Energy Commission (BAEC) has been under operation for about thirty years since its commissioning at 1986. In accordance with the demand of fundamental nuclear research works, the reactor has to operate at different power levels by utilizing a number of experimental facilities. Regarding the enquiry for safety of reactor operating personnel and radiation workers, it is necessary to know the radiation level at different strategic points of the reactor where they are often worked...
September 9, 2017: Applied Radiation and Isotopes
Suhansar Jit Sharma, Tajinder Singh, Doordarshi Singh, Amrit Singh, A S Dhaliwal
Total bremsstrahlung spectral photon distribution generated in thick targets of lead compounds Pb(CH3COO)2·3H2O, Pb(NO3)2 and PbCl2 by (90)Sr beta particles has been investigated theoretically and experimentally in the photon energy region 1-10keV. The experimental results are compared with the theoretical models describing ordinary bremsstrahlung and the theoretical model which includes polarization bremsstrahlung into ordinary bremsstrahlung, in stripped approximation. It is observed that the experimental results show better agreement with the model which describes bremsstrahlung in stripped approximation in the energy range 3-10keV...
September 9, 2017: Applied Radiation and Isotopes
Franslley Morona, Felipe R Dos Santos, André M Brinatti, Fábio L Melquiades
The rapid, simple and accurate determination of soil quality indicators is fundamental for improvements in precision agriculture and consequently in production efficiency. The objectives of this study were to determine the organic matter (OM) and total organic carbon (TOC) concentrations in agricultural soil and to discriminate soil provenance by energy-dispersive X-ray fluorescence (EDXRF) combined with principal component analysis and partial least square regression. The conventional methods used for the determination of OM and TOC concentrations are the gravimetric and Walkley-Black methods, respectively...
September 8, 2017: Applied Radiation and Isotopes
Ole Nähle
The activity of a (67)Ga solution was measured by means of the 4πβ-γ coincidence counting technique. A setup with a proportional counter and non-extending dead-time modules in the two detector channels was used. The influence of the delayed state affecting the measured count rates was taken into account by using appropriate correction formulae. The analysis requires a variation of the dead time and a subsequent extrapolation to infinite dead time. An uncertainty of about 0.5% was obtained and the result was used to make an intercomparison with the SIR of the BIPM...
September 7, 2017: Applied Radiation and Isotopes
M Fairclough, B Ellis, H Boutin, A K P Jones, A McMahon, S Alzabin, A Gennari, C Prenant
Positron Emission Tomography is an attractive imaging modality for monitoring the migration of cells to pathological tissue. We evaluated a new method for radiolabelling leukocytes with zirconium-89 ((89)Zr) using chitosan nanoparticles (CN, Z-average size 343 ± 210nm and zeta potential +46 ± 4mV) as the carrier. We propose that cell uptake of (89)Zr-loaded CN occurred in a two-step process; cell membrane interaction with (89)Zr-loaded CN was followed by a slower cell internalisation step.
September 6, 2017: Applied Radiation and Isotopes
Jiri Suran, Petr Kovar, Jana Smoldasova, Jaroslav Solc, Raf Van Ammel, Maria Garcia Miranda, Ben Russell, Dirk Arnold, Daniel Zapata-García, Sven Boden, Bart Rogiers, Johan Sand, Kari Peräjärvi, Philip Holm, Bruno Hay, Guillaume Failleau, Stephane Plumeri, Yves Laurent Beck, Tomas Grisa
Decommissioning of nuclear facilities incurs high costs regarding the accurate characterisation and correct disposal of the decommissioned materials. Therefore, there is a need for the implementation of new and traceable measurement technologies to select the appropriate release or disposal route of radioactive wastes. This paper addresses some of the innovative outcomes of the project "Metrology for Decommissioning Nuclear Facilities" related to mapping of contamination inside nuclear facilities, waste clearance measurement, Raman distributed temperature sensing for long term repository integrity monitoring and validation of radiochemical procedures...
September 1, 2017: Applied Radiation and Isotopes
Akash Tondon, Mohinder Singh, B S Sandhu, Bhajan Singh
A simple nondestructive method is presented in this study to characterize woods having different densities, thus estimating the size and depth of inhomogeneities in given wood samples using the Compton scattering technique (CST). This technique uses a collimated beam of 662-keV energy from (137)Cs radioactive source, and the scattered flux is detected by an NaI(Tl) detector. To characterize different wood samples on the basis of their densities, both scattering and transmission experiments were performed. The presence of inhomogeneities such as knots in wood was simulated by drilling cylindrical voids of diameter 9mm in the samples and then filling them with a high-density material (aluminum)...
August 31, 2017: Applied Radiation and Isotopes
Lynne King, Ryan Fitzgerald, Ronald E Tosh
The detection efficiency for large area alpha sources with adjustable heights of a raised lip around the edge were measured by 2π gas-filled proportional counter. The variations in low-energy spectral shape were modeled using a Geant4 radiation and charge transport Monte Carlo simulation, to enable extrapolation of the spectrum to zero energy. COMSOL Multiphysics finite-element analysis was used to explore changes in the spectrum gain in the presence of a lip. It qualitatively reproduced an increase in peak height due to an increasing height of the source lip...
August 31, 2017: Applied Radiation and Isotopes
Nadia Malek Saied, Najoua Mejri, Mouna Raddaoui, Mouldi Saidi
No abstract text is available yet for this article.
August 31, 2017: Applied Radiation and Isotopes
Haile Dennis, Charles Grant, John Preston
Analysis was performed to estimate radiation levels during removal and packaging of the highly-enriched uranium core of the JM-1 SLOWPOKE-2 research reactor. Due to severe limitations of space in and around the reactor pool, the core could not be removed in the conventional manner as was done for previous SLOWPOKE defuelling operations. A transfer shield, with a balance between shielding efficacy, volume and weight was designed. Fuel depletion, Monte Carlo shielding and criticality calculations were performed...
August 29, 2017: Applied Radiation and Isotopes
Prince David Preto, Vidyavathy Balraj, Bhushan S Dhabekar, S Watanabe, T K Gundu Rao, Nilo F Cano
LiF:Mg,Cu,P,Si (MCPS), a new tissue equivalent phosphor, was synthesized by solid state method. Powder x-ray diffraction and scanning electron microscope were employed to determine the structural features. The dosimetric characteristics, electron spin resonance (ESR) and defect centers of this newly prepared phosphor were investigated. The MCPS phosphor is highly sensitive when compared with LiF:Mg,Ti and LiF:Mg,Cu,P (MCP), with the TL sensitivity being 35 times and 1.3 times higher respectively. The dosimetric peak occurs at 220°C with a well defined glow curve structure similar to MCP...
August 25, 2017: Applied Radiation and Isotopes
G H Roshani, A Karami, A Salehizadeh, E Nazemi
The problem of how to precisely measure the volume fractions of oil-gas-water mixtures in a pipeline remains as one of the main challenges in the petroleum industry. This paper reports the capability of Radial Basis Function (RBF) in forecasting the volume fractions in a gas-oil-water multiphase system. Indeed, in the present research, the volume fractions in the annular three-phase flow are measured based on a dual energy metering system including the (152)Eu and (137)Cs and one NaI detector, and then modeled by a RBF model...
August 24, 2017: Applied Radiation and Isotopes
Engin Aşlar, Eren Şahiner, George S Polymeris, Niyazi Meriç
The trapping parameters of BeO thermoluminescence peaks 2 and 3 (with delocalization temperatures of 192 and 308°C respectively, obtained with heating rate of 1K/s) have been calculated using various analysis techniques, including the peak shape methods, isothermal decay, variable heating rates, the fractional glow technique and de-convolution. However, as BeO has been reported to undergo thermal quenching, both intensity as well as trapping parameters are affected, because the glow curve is distorted. Therefore, trapping parameters were calculated for both quenched and unquenched data of the aforementioned thermoluminescence peaks...
August 24, 2017: Applied Radiation and Isotopes
Farshid Tabbakh, Seyed Mahmood Sadat Kiai, Mohammad Pashaei
This is an approach to evaluate the radioisotope production by means of typical dense plasma focus devices. The production rate of the appropriate positron emitters, F-18, N-13 and O-15 has been studied. The beam-target mechanism was simulated by GEANT4 Monte Carlo tool using QGSP_BIC and QGSP_INCLXX physic models as comparison. The results for positron emitters have been evaluated by reported experimental data and found conformity between simulations and experimental reports that leads to using this code as a reliable tool in optimizing the DPF driven systems for achieving to 1GBq activity of produced radioisotope...
August 23, 2017: Applied Radiation and Isotopes
E Mandowska, R Majgier, A Mandowski
Alkali halides are wide band gap dielectric materials, which are very important for luminescence dosimetry. Nevertheless, only some of them were studied comprehensively. Potassium chloride (KCl) is alkali halide material, which shows pronounced thermoluminescence (TL) and optically stimulated luminescence (OSL). The material occurs also in natural mineral form as sylvite (or sylvine). This paper presents results of spectrally resolved thermoluminescence (SR-TL) measurements of pure KCl crystals in temperature range 300-550K for various doses of beta irradiation...
August 22, 2017: Applied Radiation and Isotopes
D Stanga, P De Felice, M Capogni
This paper describes a new approach in evaluating the surface beta contamination using the direct method of measurement. It makes use of previous results obtained in numerical modeling of electron transport in planar geometry and is mainly based on the estimation of the efficiency of contamination sources for beta radiation and its standard uncertainty using the available information concerning the component materials of the sources and their main parameters. Experimental results illustrate the appropriateness of the new approach for surface beta contamination measurements...
August 22, 2017: Applied Radiation and Isotopes
Feng Zhang, Quanying Zhang, Juntao Liu, Xinguang Wang, He Wu, Wenbao Jia, Yongzhou Ti, Fei Qiu, Xiaoyang Zhang
Pulsed neutron gamma density logging (NGD) is of great significance for radioprotection and density measurement in LWD, however, the current methods have difficulty in quantitative calculation and single factor analysis for the inelastic gamma field distribution. In order to clarify the NGD mechanism, a new method is developed to describe the inelastic gamma field distribution. Based on the fast-neutron scattering and gamma attenuation, the inelastic gamma field distribution is characterized by the inelastic scattering cross section, fast-neutron scattering free path, formation density and other parameters...
August 21, 2017: Applied Radiation and Isotopes
Sylvia Badwar, Reetuparna Ghosh, Bioletty M Lawriniang, Vibha Vansola, Y S Sheela, Haladhara Naik, Yeshwant Naik, Saraswatula V Suryanarayana, Betylda Jyrwa, Srinivasan Ganesan
The formation cross-section of medical isotope (99)Mo from the (98)Mo(n,γ) reaction at the neutron energy of 0.025eV and from the (100)Mo(n,2n) reaction at the neutron energies of 11.9 and 15.75MeV have been determined by using activation and off-line γ-ray spectrometric technique. The thermal neutron energy of 0.025eV was used from the reactor critical facility at BARC, Mumbai, whereas the average neutron energies of 11.9 and 15.75MeV were generated using (7)Li(p,n) reaction in the Pelletron facility at TIFR, Mumbai...
August 19, 2017: Applied Radiation and Isotopes
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"