scholarly journals Determination of Gamma-Ray Shielding Parameters for Concretes and Dosimeters Using MCNPX

2020 ◽  
Vol 8 (1) ◽  
pp. 73-79
Author(s):  
V. P. Singh ◽  
Huseyin Ozan Tekin
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Simulation Method ◽  
Radiological Protection ◽  
Simulation Tool ◽  
Alternative Method ◽  
Standard Geometry ◽  
Good Agreement

Gamma-ray shielding parameter for some concretes and dosimeters having large scale applications in radiological protection are presented using MCNPX (version 2.4.0) at different energies. The MCNPX results are compared with experimental, MCNP and XCOM data, and good agreement is being noted. Present study indicates that MCNPX simulation method is suitable and reliable simulation tool to be used as an alternative method for the investigation of gamma-ray interaction. The present geometry can be used as standard geometry for MCNPX simulation for low- as well as high-Z materials.

scholarly journals A union neutron-gamma logging method for determination of uranium-radium disequilibrium coefficient

2020 ◽  
Vol 35 (2) ◽  
pp. 103-108
Author(s):  
Rui Chen ◽  
Cheng-Yuan Luo ◽  
Hai-Tao Wang ◽  
Zhi-Feng Liu ◽  
Xiong-Jie Zhang ◽  
...  
Keyword(s):  
Count Rate ◽  
Gamma Ray ◽  
Uranium Content ◽  
Fission Neutron ◽  
Characteristic Peak ◽  
Prompt Fission ◽  
Logging Tool ◽  
Peak Count ◽  
Good Agreement

Owing to the influence of continuous running of ground water, the uranium atoms can be separated physically from their daughters for the reason of different solubilities and the uranium deposit often shows the disequilibrium feature between uranium and its daughter products (radium principally). It is important, when spectral gamma ray logging, to quantify the uranium content which can cause inaccuracy of the result. This paper, based on spectral ? ray logging method, proposes a neutron-gamma logging method to determine the coefficient of uranium-radium disequilibrium. In this method, characteristic peak count rate of uranium is taken from prompt fission neutron logging, whereas characteristic peak count rate of radium, thorium and potassium are taken from spectral gamma ray logging. Based on this method, the union logging tool including epithermal neutron, thermal neutron, and gamma detector along with D-T generator, have been developed. The experimental results, in standard model wells, show that this method is in good agreement within 7% in core assay results. It shows that the union neutron-? logging method can be used for field uranium logging jobs.

scholarly journals Theoretical and experimental determination of mass attenuation coefficients of lead-based ceramics and their comparison with simulation

2016 ◽  
Vol 31 (2) ◽  
pp. 142-149 ◽  
Author(s):  
Alireza Vejdani-Noghreiyan ◽  
Elham Aliakbari ◽  
Atiyeh Ebrahimi-Khankook ◽  
Mahdi Ghasemifard
Keyword(s):  
Gamma Ray ◽  
Mass Attenuation Coefficient ◽  
X Ray Diffraction ◽  
Attenuation Coefficients ◽  
X Ray ◽  
Simulation Results ◽  
Theoretical Results ◽  
Good Agreement ◽  
Mass Attenuation

Mass attenuation coefficient of lead-based ceramics have been measured by experimental methods and compared with theoretical and Monte Carlo simulation results. Lead-based ceramics were prepared using mixed oxide method and the X-ray diffraction analysis was done to evaluate the crystal structure of the produced handmade ceramics. The experimental results show good agreement with theoretical and simulation results. However at two gamma ray energies, small differences between experimental and theoretical results have been observed. By adding other additives to ceramics and observing the changes in the shielding properties such as flexibility, one can synthesize and optimize ceramics as a neutron shield.

scholarly journals Radiation resistance of novel SARS-CoV-2: A Monte Carlo investigation on characterization and determination of gamma-ray attenuation properties

2020 ◽  
Author(s):  
H.O. Tekin ◽  
U. Kara ◽  
Shams A.M. Issa ◽  
Ibrahim Inanc ◽  
O. Kilicoglu ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Radiation Resistance ◽  
Gamma Ray ◽  
Simulation Method ◽  
Data Bank ◽  
World Health ◽  
Monte Carlo Investigation ◽  
Health Organization ◽  
Buildup Factors

Abstract In late December 2019, the new viral pneumonia outbreak was first detected in Wuhan, the largest metropolitan area in China's Hubei province. The 2019–20 coronavirus pandemic is an ongoing pandemic, caused by the severe acute respiratory syndrome-2 (SARS-CoV-2), was named as Coronavirus disease 2019 (COVID-19) by World Health Organization (WHO). It is well known that radiation can cause mutations in bacteria and viruses. Therefore, characterization of the radiation resistance and interaction properties of viruses provides the opportunity in terms of risk assessment and future aspects. In this study, 3 types of viruses (SARS-CoV-CAS Number 587886-51-9, Influenza-CAS Number 141368-69-6 and SARS-CoV-2 GlycoProtein 6VSB.) were modeled with the Monte Carlo simulation method (MCNPX version 2.6.0). The vital radiation attenuation properties such as linear attenuation coefficients, energy absorption buildup factors (EABF), exposure buildup factors (EBF), relative dose distributions (RDD) were examined using advanced simulation methods. Moreover, the spike protein of SARS-CoV-2 is modelled from the structures in the Protein Data Bank. As a result of the study, we could say that the most radiation resistance was observed in SARS-CoV when compared with Influenza and Covid-19. It could be one of the reasons for SARS-CoV’s resistance to mutation from its outbreak time. On the other hand, Covid-19 is more resistant to radiation than Influenza. Therefore it could be expected that Covid-19 would have the similar behaviors against ionizing radiation as Influenza has.

scholarly journals Determination of in situ detection efficiency for IM-NAA of non-standard geometrical samples

2021 ◽  
Vol 9 (4) ◽  
pp. 27-33
Author(s):  
Duy Quang Nguyen ◽  
Van Cuong Trinh ◽  
Tuan Anh Tran ◽  
Van Doanh Ho ◽  
Thi Tho Nguyen ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Standard Geometry ◽  
Activation Products ◽  
Geometrical Effects ◽  
In Situ Detection ◽  
Relative Detection

The k0-based internal mono-standard (IM) method was first proposed for the concentration analysis of samples of non-standard geometry in the 2000s. The method has demonstrated several advantages such as the elimination of gamma-ray self-attenuation and geometrical effects. On the other hand, the accuracy of the method principally depends on the in situ relative detection efficiency, which requires to be obtained in each measurement. Therefore, the relative detection efficiency is always under consideration for the improvement of the analysis results. The present paper describes a simple and automatic procedure for the determination of the relative efficiency using one or more activation products emitting gamma rays over a considered range of the spectrum. The procedure can be applied for INAA and PGNAA analysis.

AN EMPIRICAL APPROACH TO THE DETERMINATION OF POROSITY, SHALE PERCENTAGE, AND PERMEABILITY OF PERMIAN SANDSTONES IN THE COOPER BASIN, SOUTH AUSTRALIA

1976 ◽  
Vol 16 (1) ◽  
pp. 111
Author(s):  
C. R. Porter
Keyword(s):  
Gamma Ray ◽  
South Australia ◽  
Core Values ◽  
Empirical Approach ◽  
Good Agreement ◽  
Cooper Basin

Because of the limited yet adequate logging program run in Cooper Basin wells, porosity has been the most difficult parameter to calculate on a zone-by-zone basis. Empirically derived porosities from a gamma-ray (GK)-sonie (Δt) cross-plot show good agreement with core values of porosity. Furthermore shale percentages calculated from these porosities are in good agreement with shale values derived from crossplot techniques involving sonic, density and neutron log response parameters. An approximation of permeability may also be derived from a further simplified chart.

scholarly journals Measurement of 238U, 232Th and 222Rn concentrations in different table oils samples. Determination of committed effective doses received by consumers following the ingestion of table oil.

2019 ◽  
Vol 25 (4) ◽  
pp. 201-209
Author(s):  
Rodouan Touti
Keyword(s):  
Original Method ◽  
Alpha Particles ◽  
Tunisian Population ◽  
Radiological Protection ◽  
Average Dose ◽  
Italian Population ◽  
Nuclear Track Detectors ◽  
Effective Doses ◽  
Good Agreement

Abstract The main objective of our work is to measure 238U, 232Th, 222Rn and 220Rn in different table oil samples using a method based on the use of two types of solid nuclear track detectors: CR- 39 and LR-115 II in order to determine the doses of radiation received by the individuals following ingestion of the samples of table oil studied. Indeed, we have developed an original method based on the determination of the detection efficiencies of CR-39 and LR-115 II solid nuclear track detectors for alpha particles emitted from the uranium 238 and thorium 232 series to evaluate 238U, 232Th, 222Rn and 220Rn concentrations in different table oil samples. We were able to determine doses of radiation due to 238U, 232Th and 222Rn received by individuals of the Moroccan, French, Italy, Spain and Tunisia populations following the ingestion of table oil. The effective doses committed due to 238U, 232Th, and 222Rn following the ingestion of the table oil by the consumers were determined. The maximum total committed effective dose was found equal to (10±0.7) µSv·y−1 of the Moroccan population, (11.6±0.7) µSv·y−1 of the French population, (10.3±0.7) µSv.y−1 of the Italian population, (10.4±0.5) µSv·y−1 of the Spanish population and (10.5±0.7) µSv·y−1 of the Tunisian population is much lower than the average dose given by the United Nations Scientific Committee on the Effects of Atomic Radiation [1] for ingestion (0.2 to 0.8 mSv·y−1). The results obtained using our method are in very good agreement with those obtained using the model of the International Commission on Radiological Protection

Enrichment analysis of uranium in uranium oxide by gamma-ray spectrometry without using calibration standards

2000 ◽  
Vol 88 (2) ◽  
Author(s):  
Y. Nir-El
Keyword(s):  
Gamma Rays ◽  
Uranium Oxide ◽  
Gamma Ray ◽  
Enrichment Analysis ◽  
Gamma Ray Spectrometry ◽  
Uranium Enrichment ◽  
Calibration Standards ◽  
Certified Values ◽  
Good Agreement

An analytical method for the determination of uranium enrichment in uranium oxide without using any calibration standards is described. Very good agreement between the measured and certified values was obtained in the analysis of a Standard Reference Material. Precise energies and emission probabilities were derived for two weak gamma-rays of

scholarly journals Numerical simulations of the agitation generated by coarse-grained bubbles moving at large Reynolds number

2021 ◽  
Vol 926 ◽  
Author(s):  
F. Le Roy De Bonneville ◽  
R. Zamansky ◽  
F. Risso ◽  
A. Boulin ◽  
J.-F. Haquet
Keyword(s):  
Reynolds Number ◽  
Large Scale ◽  
Hydrodynamic Force ◽  
Bubble Columns ◽  
Coarse Grained ◽  
Large Reynolds Number ◽  
Volume Source ◽  
Mesh Grid ◽  
Good Agreement

We present a numerical method for simulating the flow induced by bubbles rising at large Reynolds number. This method is useful to simulate configurations of large dimensions involving a great number of bubbles. The action that each bubble exerts on the liquid is modelled as a volume source of momentum distributed over a few mesh-grid elements. The flow in the vicinity of the bubbles is thus not finely resolved. The bubbles are treated as Lagrangian particles that move under the influence of the hydrodynamic force exerted by the liquid. The determination of this force on a given bubble requires knowledge of the liquid flow that is undisturbed by this bubble. A model is developed to accurately estimate this disturbance for large-Reynolds-number objects and get rid of any spurious self-induced effect. Thanks to that, a homogeneous swarm of rising bubbles is simulated. Comparisons with experiments show a good agreement with the flow scales larger than the bubbles, which turn out to be controlled by the interactions between bubble wakes and rather independent of unresolved smaller scales. This method can be used to study the coupling between bubble-induced agitation and large-scale motions, such as those produced in industrial bubble columns.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Determination of Myocardial FFA Elimination Rates by Functional Images of Uncorrected Half-Time Values

1984 ◽  
Vol 23 (06) ◽  
pp. 277-282 ◽  
Author(s):  
A. Van Lingen ◽  
G. Westera ◽  
M. van ◽  
W. Den Hollander ◽  
E. E. Van der Wall ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Regions Of Interest ◽  
Heptadecanoic Acid ◽  
Half Time ◽  
Alternative Method ◽  
Functional Images ◽  
Functional Image ◽  
Back Ground ◽  
Objective Determination

SummaryThis paper presents an alternative method of demarcating regions of in terest over the myocardium after ad ministration of 123I-heptadecanoic acid to patients with coronary artery disea se. In a matrix of 32 × 32 pixels the elimination rates of the radioactivity, which are not corrected for back ground activity, are visualized per pixel in a functional image. The func tional image showed areas in the myocardium with high values of uncorrected elimination rates. These areas corresponded with the tracer defects on the scintigram. Corrected elimination rates obtained from re gions of interest of functional images were comparable with those of scinti grams. Thus based on functional im ages of uncorrected elimination rates a reliable, objective determination of regions of interest over normal and abnormal myocardium can be made.

Sign in / Sign up

Export Citation Format

Share Document