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Applied Radiation and Isotopes

Do Hyeon Yoo, Wook-Geun Shin, Jaekook Lee, Yeon Soo Yeom, Chan Hyeong Kim, Byung-Uck Chang, Chul Hee Min
After the Fukushima accident in Japan, the Korean Government implemented the "Act on Protective Action Guidelines Against Radiation in the Natural Environment" to regulate unnecessary radiation exposure to the public. However, despite the law which came into effect in July 2012, an appropriate method to evaluate the equivalent and effective doses from naturally occurring radioactive material (NORM) in consumer products is not available. The aim of the present study is to develop and validate an effective dose coefficient database enabling the simple and correct evaluation of the effective dose due to the usage of NORM-added consumer products...
August 9, 2017: Applied Radiation and Isotopes
H Beigzadeh Jalali, E Salimi, J Rahighi
Gas bremsstrahlung is generated in high energy electron storage ring and accompanies the synchrotron radiation into the beamlines, where both strike the various components of the beamline. In this paper, radiation shielding calculations for secondary gas bremsstrahlung are performed for the First Optics Enclosure (FOE) of X-ray powder diffraction (XPD) beamline of the Iranian Light Source Facility. Dose equivalent rate (DER) calculations are accomplished using FLUKA Monte Carlo code. A comprehensive study of DER distribution at the back wall, sides and roof are given...
August 8, 2017: Applied Radiation and Isotopes
J J Okonda, K H Angeyo, J M Mangala, S M Kisia
Compton scatter-modulated fluorescence and multivariate chemometric (artificial neural network (ANN) and principal component regression (PCR)) calibration strategy was explored for direct rapid trace biometals (Mn, Fe, Cu, Zn, Se) analysis in "complex" matrices (model soft tissues). This involved spectral feature selection (multiple fluorescence signatures) normalized to or in conjunction with Compton scatter. ANN model resulted in more accurate trace biometal determination (R(2)>0.9) compared to PCR. Hybrid nested (ANN and PCR) approach led to optimized accurate biometals' concentrations in Oyster tissue (≤ ± 10%)...
August 8, 2017: Applied Radiation and Isotopes
Fernando Cervantes-Sanchez, Ivan Cruz-Aceves, Arturo Hernandez-Aguirre, Sergio Solorio-Meza, Teodoro Cordova-Fraga, Juan Gabriel Aviña-Cervantes
Segmentation of coronary arteries in X-ray angiograms represents an essential task for computer-aided diagnosis, since it can help cardiologists in diagnosing and monitoring vascular abnormalities. Due to the main disadvantages of the X-ray angiograms are the nonuniform illumination, and the weak contrast between blood vessels and image background, different vessel enhancement methods have been introduced. In this paper, a novel method for blood vessel enhancement based on Gabor filters tuned using the optimization strategy of Differential evolution (DE) is proposed...
August 5, 2017: Applied Radiation and Isotopes
D Gurau, S Boden, O Sima, D Stanga
This paper provides guidance for determining the neutron activation profile of core drill samples taken from the biological shield of nuclear reactors using gamma spectrometry measurements. Thus, it provides guidance for selecting a model of the right form to fit data and using least squares methods for model fitting. The activity profiles of two core samples taken from the biological shield of a nuclear reactor were determined. The effective activation depth and the total activity of core samples along with their uncertainties were computed by Monte Carlo simulation...
August 4, 2017: Applied Radiation and Isotopes
F Molina, P Aguilera, J Romero-Barrientos, H F Arellano, J Agramunt, J Medel, J R Morales, M Zambra
We present a methodology to obtain the energy distribution of the neutron flux of an experimental nuclear reactor, using multi-foil activation measurements and the Expectation Maximization unfolding algorithm, which is presented as an alternative to well known unfolding methods such as GRAVEL. Self-shielding flux corrections for energy bin groups were obtained using MCNP6 Monte Carlo simulations. We have made studies at the at the Dry Tube of RECH-1 obtaining fluxes of 1.5(4)×10(13)cm(-2)s(-1) for the thermal neutron energy region, 1...
August 4, 2017: Applied Radiation and Isotopes
M Santibáñez, R Saavedra, M Vásquez, F Malano, P Pérez, M Valente, R G Figueroa
The present work is devoted to optimizing the sensitivity-doses relationship of a bench-top EDXRF system, with the aim of achieving a detection limit of 0.010mg/ml of gold nanoparticles in tumor tissue (clinical values expected), for doses below 10mGy (value fixed for in vivo application). Tumor phantoms of 0.3cm(3) made of a suspension of gold nanoparticles (15nm AurovistTM, Nanoprobes Inc.) were studied at depths of 0-4mm in a tissue equivalent cylindrical phantom. The optimization process was implemented configuring several tube voltages and aluminum filters, to obtain non-symmetrical narrow spectra with fixed FWHM of 5keV and centered among the 11...
August 4, 2017: Applied Radiation and Isotopes
Kiran Kumar Solingapuram Sai, H Donald Gage, Frankis Almaguel, Bryan Neth, Timothy M Hughes, Sebastien Tremblay, Christian-Alexandre Castellano, Stephen C Cunnane, Matthew J Jorgensen, Suzanne Craft, Akiva Mintz
We automated radiochemical synthesis of 1-[(11)C]acetoacetate in a commercially available radiochemistry module, TRASIS AllInOne by [(11)C]carboxylation of the corresponding enolate anion generated in situ from isopropenylacetate and MeLi, and purified by ion-exchange column resins.1-[(11)C]acetoacetate was synthesized with high radiochemical purity (95%) and specific activity (~ 66.6GBq/µmol, n = 30) with 35% radiochemical yield, decay corrected to end of synthesis. The total synthesis required ~ 16min. PET imaging studies were conducted with 1-[(11)C]acetoacetate in vervet monkeys to validate the radiochemical synthesis...
August 2, 2017: Applied Radiation and Isotopes
Cong Wei, Kelly Garnick, Thomas Scott, Elon Malkin, Jennifer Szymanski, Steve Laskos, Jeffrey Raimondi, James Cocks, Kara Morris, Wilhelm Mueller, James Zickefoose
A portable CeBr3 based gamma-ray detection system was designed and built for rapid turnaround, high throughput, real-time, and in situ sample analysis. The new technique allows automated data transmission from the field unit to a central laboratory controller to ensure laboratory quality of the data collected by field users without gamma-ray spectroscopy expertise. The method validation data indicates that the system's data quality objectives are adequate for radiological or nuclear emergency response or targeted surveillance programs where gamma-ray analysis is needed...
August 2, 2017: Applied Radiation and Isotopes
M Mirenda, D Rodrigues, C Ferreyra, P Arenillas, G P Sarmiento, N Krimer, M L Japas
We study the wavelength shift of the Čerenkov light - generated in the ionic liquid (BMIMCl) - caused by the addition of the highly fluorescent ionic liquid (BMIMHPTS). (18)F and (32)P efficiencies increases up to 124% and 14%, respectively, compared with the values obtained with pure BMIMCl. With this improvement, ionic liquid mixtures become a good alternative - when using the TDCR-Cherenkov technique - to standardize radionuclides having electron emissions energies close to the threshold energy in water (∼ 260keV)...
August 1, 2017: Applied Radiation and Isotopes
E Gören, Ş Turhan, A Kurnaz, A M K Garad, C Duran, F A Uğur, Z Yeğingil
Natural radionuclides are released into the environment together with fly ash from the coal-burning power plant and cause an increase in the natural radioactivity in environmental samples. The study concerns to the evaluation the influence of Kangal lignite-burning power plant (LBPP) with a power of 457 MWe, which has been in operation since 1989, on natural radionuclide a concentration in surface soil samples around it. Activity concentrations of natural radionuclides ((226)Ra, (232)Th, (40)K and (222)Rn) in the soil samples, and emanation coefficient (EC) and mass (ERM) and surface (ERS) exhalation rate of radon were determined by using a gamma-ray spectrometer with an HPGe detector...
August 1, 2017: Applied Radiation and Isotopes
Rui Shi, Xianguo Tuo, Honglong Zheng, Huailiang Li, Yangyang Xu, Qibiao Wang, Chao Deng
An algorithm based on moment estimation is presented to determine the initial parameters of the particle spectrum peak shape function for the iteration fitting procedure. The algorithm calculates the mean value, variance, and third-order central moment by using the spectrum peak data, solves the parameters of the fitting function, and then provides them as the initial values to the Levenberg-Marquardt algorithm to ensure convergence and optimized fitting. The effectiveness of the proposed algorithm was tested by gamma and alpha spectra...
July 31, 2017: Applied Radiation and Isotopes
N Ghal-Eh, M Kalaei, A Mohammadi, H R Vega-Carrillo
In this study, a conventional Bonner sphere spectrometer, together with (6)LiI(Eu) inorganic scintillator used as the central detector, was used to obtain the neutron energy spectrum of an (241)Am-Be source. To achieve this, we calculated the response matrices corresponding to eight different sizes of polyethylene spheres for the neutron energies ranging from about 10(-7) to 15MeV in 54 energy groups by using the MCNPX2.6 code, and the (241)Am-Be neutron spectrum was obtained using a modified version of the neutron spectrum unfolding code, AFITBUNKI...
July 29, 2017: Applied Radiation and Isotopes
Naoko Nakashima, Emerenciana B Duran
The Provisional Technical Secretariat (PTS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) Organization organizes Proficiency Test Exercises (PTE) annually for the 16 radionuclide laboratories supporting its network of radionuclide air monitoring stations since 2000. These laboratories re-analyze samples from radionuclide stations for quality control. The PTEs, in turn, are a means of checking the quality of analytical results provided by laboratories. Laboratories implement corrective actions for PTE discrepant results...
July 28, 2017: Applied Radiation and Isotopes
Marcial Vásquez Arteaga, Víctor Murillo Caballero, Kelman Marín Rengifo
The dose to kidneys of newborns and 1-year old children was calculated using the MIRD methodology. In order to perform renal studies radiopharmaceutical like (99m)Tc-DTPA, (99m) Tc-MAG3 and (99m)Tc-DMSA are used. Here, besides the anatomic and structure information of kidneys another data are provided in benefit of patient, however during the radioisotope decay emitted radiations delivers, totally or partially, their energy. Therefore is important to estimate the internal radiation dose of the organs. The largest dose to kidneys comes from the self-dose and it is due to the charged particles emitted during (99m)Tc decay...
July 28, 2017: Applied Radiation and Isotopes
Richard M Essex, Jaqueline L Mann, Ross W Williams, William S Kinman, Amélie Hubert, Megan E Bennett, Alkiviadis Gourgiotis
A new reference material was characterized for (229)Th molality and thorium isotope amount ratios. This reference material is intended for use in nuclear forensic analyses as an isotope dilution mass spectrometry spike. The reference material value and expanded uncertainty (k = 2) for the (229)Th molality is (1.1498 ± 0.0016) × 10(-10)molg(-1) solution. The value and expanded uncertainty (k = 2) for the n((230)Th)/n((229)Th) ratio is (5.18 ± 0.26) × 10(-5) and the n((232)Th)/n((229)Th) ratio is (3.815 ± 0...
July 27, 2017: Applied Radiation and Isotopes
Denis Glavič-Cindro, Drago Brodnik, Francesco Cardellini, Pierino De Felice, Dušan Ponikvar, Matjaž Vencelj, Toni Petrovič
A compact portable aerosol sampling and measurement device was developed at Jožef Stefan Institute (JSI). A CeBr3 scintillation detector is positioned centrally within a concertinaed filter assembly. It provides continuous and via network communications on-line monitoring of low levels of airborne radioactive particulates. The evaluation of the response of the device to the natural background at controlled conditions with elevated radon concentrations, performed at the National Institute of Ionizing Radiation Metrology of ENEA, is presented...
July 27, 2017: Applied Radiation and Isotopes
Wilson Otto Gomes Batista
This study aimed at the development and validation of the models of phantom: CQ-02-IFBA and CQ-01-IFBA, the first filled with water and the second fully with a solid structure in polymethylmethacrylate (PMMA). Both models allow its use in various models of cone beam computed tomography (CBCT), independent of the size of the field of view. The two phantoms are used to evaluate seven parameters of quality control: intensity or average value of pixels of five different plastics, signal to noise ratio, resolution, low contrast, spatial resolution, the accuracy of distances on the z axis, the geometric distortion and image uniformity...
July 27, 2017: Applied Radiation and Isotopes
Amin Asgharzadeh Alvar, Mohammad Reza Deevband, Meghdad Ashtiyani
Neutron energy spectrum unfolding has been the subject of research for several years. The Bayesian theory, Monte Carlo simulation, and iterative methods are some of the methods that have been used for neutron spectrum unfolding. In this study, the radial basis function (RBF), multilayer perceptron, and artificial neural networks (ANNs) were used for the unfolding of neutron spectrum, and a comparison was made between the networks' results. Both neural network architectures were trained and tested using the same data set for neutron spectrum unfolding from the response of LiI detectors with Eu impurity...
July 26, 2017: Applied Radiation and Isotopes
Mustafa Yiğit
The aim of the present work is to develop simple empirical formulae based on the Q-value dependence of the nuclear reaction for estimating the (n,t) cross sections at energies near 14.6MeV. The (n,t) cross sections are analyzed in terms of the compound nucleus model. The empirical formulae based on the compound nucleus model are obtained giving the cross section in terms of the investigated reaction Q-values instead of the widely used asymmetry parameter. In addition, the new formulae include two fitting parameters on even-A and odd-A target nuclei with 27 ≤A≤ 204...
July 26, 2017: Applied Radiation and Isotopes
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