17 research outputs found
The determination of the mean value of the non-homogenous background radiation and the measurement uncertainty using welch-satterthwaite equation
In this paper, the procedure for determination of the mean value of non-homogenous background radiation and the expression of measurement uncertainty is considered. The background radiation is described using the Student's distribution, and the measurement uncertainty using the Welch-Satterthwaite equation. The proposed algorithm was experimentally verified under well-controlled laboratory conditions and satisfactory results were obtained
Contamination of the Å ar Mountains Aquatorium ā Kosovo with Depleted Uranium
The main objective of this study was to estimate the environmental and health risk of the Å ar Mountains (Kosovo) for depleted uranium contamination. The risk assessment of the contamination is needed since, in the spring of 1999, conflict with bombarding took place in the territory of the Western Balkans, during which depleted uranium ammunition was used. In Serbia and Montenegro, such tests were performed; based on them, some territories were decontaminated. Å ar Mountains is particularly important as it is one of the few water-rich areas in Kosovo. Therefore, soil and water samples were taken from characteristic places in the Å ar Mountains aquatorium. Tests of the samples were performed under well-controlled conditions. The measurement uncertainty was less than 5%. Based on the obtained results, it was concluded that there was no contamination of the Å ar Mountains with depleted uranium. This conclusion can be extended to the broader area around the Å ar Mountains, as it is a safe area surrounded by high mountains
The efficiency of gas-filled surge arresters in the environment contaminated by non-ionizing radiation of fusion reactors
The research presents an experiment with a model of an electronic generator for energy injection into the plasma of a fusion reactor. By recording a non-ionizing field in the vicinity of a fusion reactor, it was determined that this field has an extremely high growth rate. At the site of the maximum intensity of the field of non-ionizing radiation, commercial surge arresters with a flexible model of surge arresters were used for experimentation. It has been found that the commercial surge arresters have an efficiency of about 20%. For the efficiency of the flexible model, it was found to be slightly less than 40% (and to be achieved by the application of alpha particle radiation). Since neither of these efficiencies guarantee reliable operation of the gas-filled surge arrester, it was concluded that essential electronics in the vicinity of the fusion generator must be protected. However, since this protection can only be implemented in a fusion reactor, the fact remains that the environment of such a reactor is extremely contaminated with non-ionizing radiation. Commercial surge voltages are isolated for testing since the protection of electronic circuits from fast overvoltages is a critical point for the functioning of modern electronics
Application of complex statistical distributions and natural isotopes of hydrogen and oxygen for assessment of water origin in Å ar mountains aquatorium
This study considers the possibility of applying natural isotopes of water, tritium, and oxygen 18O, to analyze the connection between groundwater, surface, and precipitation waters. This analysis also enables the determination of the age of groundwater, separated from the cycle of water circulation in nature. Based on these methods, it is possible to reliably determine, by chronologically accurate method, the possibility of industrial application and application for human needs of the waters of this aquatorium. Ā© 2020, Vinca Inst Nuclear Sci. All rights reserved
Survey of radiofrequency radiation levels around GSM base stations and evaluation of measurement uncertainty
This paper is a summary of broadband measurement values of radiofrequency radiation around GSM base stations in the vicinity of residential areas in Belgrade and 12 other cities in Serbia. It will be useful for determining non-ionizing radiation exposure levels of the general public in the future. The purpose of this paper is also an appropriate representation of basic information on the evaluation of measurement uncertainty
Synergy of radioactive 241Am and the effect of hollow cathode in optimizing gas-insulated surge arresters characteristics
The paper discusses the possibility of improving the character of gas surge
arresters. Examined were: the magnetic field effect, the effect of the
hollow cathode, and the effect of the alpha radiation source 241Am.
Numerical and real experiments conducted are presented together with
theoretical interpretations of the obtained results. Real experiments were
carried out on a model of a gas surge arrester spatially constructed for
experiments presented in this paper. The model was designed in such a way
that it was possible to change all the relevant parameters of the gas
surge arrester model. Experiments were conducted under well-controlled
laboratory conditions. The tests were performed with d. c. and impulse
voltage. The results obtained by experiments were processed by sophisticated
statistical methods. The expressed measurement uncertainty of the
experimental procedure showed a high statistical reliability of the obtained
results. Based on the results of the research, the model of a gas surge
arrester, in which the effect of the hollow cathode and the radioactive
source 241Am were combined, unambiguously proved to have the best
characteristics
The determination of the mean value of the non-homogenous background radiation and the measurement uncertainty using Welch-Satterthwaite equation
In this paper, the procedure for determination of the mean value of
non-homogenous background radiation and the expression of measurement
uncertainty is considered. The background radiation is described using the
Student's distribution, and the measurement uncertainty using the
Welch-Satterthwaite equation. The proposed algorithm was experimentally
verified under well-controlled laboratory conditions and satisfactory results
were obtained. [Project of the Serbian Ministry of Education, Science and
Technological Development, Grant no. 171007
Comparison of the empirical variances and mean values of normally distributed populations of nuclear counts
This paper discusses the possibility of applying the F-test and double t-test
in problems related to the identification of number of radioactive isotopes
in a contaminated area by using only counters for radiation detection. The
descriptions of the F-test and the double t-test are given along with the
corresponding tabular values that enable their implementation. Finally, the
experiment is presented via two radioactive samples. The results of the
experiment were treated in the manner proposed in the paper and satisfactory
results were obtained. [Projekat Ministarstva nauke Republike Srbije, br.
171007
Influence of the scintillation crystal option on the detector response of pet devices
Positron emission tomography is a technology that provides unique and
exquisite possibilities in functional diagnostics, in the sense that it is
the most efficient and most reliable method for obtaining information about
biochemical activity and cellular metabolism in the body, by determining
exact localization and performing semi-quantitative assessment of the
distribution of a radioactive tracer. This paper compares the characteristics
of recently introduced lutetium based crystals to those of conventionally
used bismuth-ortho-germanate scintillators; both options are used as
scintillation detectors within the positron emission tomography systems.
Energy resolution and scintillation decay time of lutetium based crystals and
bis-muth-ortho-germanate crystals was experimentally tested. Main
scintillation detector parameters which affect the resulting detector
response are considered and analyzed, since they serve as the basis for a
positron emission tomography medical image. [Projekat Ministarstva nauke
Republike Srbije, br. 171007
Simulated radiation effects in the superinsulating phase of titanium nitride films
This paper investigates possible effects of alpha particle and ion beam irradiation on the properties of the superinsulating phase, recently observed in titanium nitride films, by using numerical simulation of particle transport. Unique physical properties of the superinsulating state are considered by relying on a two-dimensional Josephson junction array as a model of material structure. It is suggested that radiation-induced change of the Josephson junction charging energy would not affect the current-voltage characteristics of the superinsulating film significantly. However, it is theorized that a relapse to an insulating state with thermally activated resistance is possible, due to radiation-induced disruption of the fine-tuned granular structure. The breaking of Cooper pairs caused by incident and displaced ions may also destroy the conditions for a superinsulating phase to exist. Finally, even the energy loss to phonons can influence the superinsulating state, by increasing the effective temperature of the phonon thermostat, thereby reestablishing means for an energy exchange that can support Cooper pair tunneling