TY  - CONF
AU  - Rubinjoni, Luka
AU  - Stanković, Srboljub
AU  - Karadžić, Katarina
AU  - Lončar, Boris
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12138
AB  - Operations involving grout, mortar and concrete are commonly used in radioactive waste management. Materials based on Portland cement (OPC) have numerous applications, ranging from construction of facilities, radioactive shielding, production of different casings and containers, to waste conditioning procedures (solidification, cementation, grouting). These materials are well known and well standardized, and regulated both internationally and at the national level. OPC is readily available, cost effective and comes in formulations suited for the construction industry. In nuclear and radioactive waste management industries, some challenges with the use of OPC based materials have been recognized (including the durability of concrete under thermal stress, long term stability of OPC binders, and radiolysis of contained water), and have been addressed either by optimizing OPC material formulations, or by using alternative binders. One promising alternative binder is geopolymer, a type of alkali activated binder, solidified by cross linking aluminosilicates into an amorphous matrix. Geopolymer is formed by activation of fine powder with pozzolanic properties with an alkali solution of sodium silicate (water glass). During geopolymerization, water acts primarily as a solvent, unlike the reactions during the setting of OPC, where hydration plays a key role. Various base materials, ranging from metakaolin to byproducts such as fly-ash and blast furnace slag, can be used. Coal fly-ash is an inexpensive raw material with low CO2 footprint (compared to OPC), with potential applications in radioactive waste conditioning. To our knowledge, the effect of ionizing radiation on geopolymer set time hasn’t been explored. We have measured the initial and final set time for fly-ash geopolymer paste, based on the SRPS EN 196-3 standard, irradiated by gamma rays in a Co-60 reference field on position with air kerma rate of 3.42 mGy/s. The binder paste was prepared using fly-ash from TENT B power plant’s electrostatic filters without further sieving, activated by water glass with module 1.5 and mixed with distilled water until satisfactory flow was obtained, and poured into sample and control molds. Initial and final set times for irradiated sample and non irradiated control were determined by Vicat apparatus. The irradiated sample demonstrated 11% shorter initial set time, and 16% shorter final set time, compared to control. These set times allow satisfactory working times for geopolymer grouts and mortars. The effect of ionizing radiation on set times and other properties of coal fly-ash based materials must be accounted for in all stages of application, from small scale testing and simulations, to full scale tests and production environments.
PB  - Niš : Sievert Association
C3  - RAP 2019 : International conference on radiation applications : Book of abstracts
T1  - The effect of Co-60 gamma irradiation on coal fly-ash geopolymer set times
SP  - 62
EP  - 62
UR  - https://hdl.handle.net/21.15107/rcub_vinar_12138
ER  - 

@conference{
author = "Rubinjoni, Luka and Stanković, Srboljub and Karadžić, Katarina and Lončar, Boris",
year = "2019",
abstract = "Operations involving grout, mortar and concrete are commonly used in radioactive waste management. Materials based on Portland cement (OPC) have numerous applications, ranging from construction of facilities, radioactive shielding, production of different casings and containers, to waste conditioning procedures (solidification, cementation, grouting). These materials are well known and well standardized, and regulated both internationally and at the national level. OPC is readily available, cost effective and comes in formulations suited for the construction industry. In nuclear and radioactive waste management industries, some challenges with the use of OPC based materials have been recognized (including the durability of concrete under thermal stress, long term stability of OPC binders, and radiolysis of contained water), and have been addressed either by optimizing OPC material formulations, or by using alternative binders. One promising alternative binder is geopolymer, a type of alkali activated binder, solidified by cross linking aluminosilicates into an amorphous matrix. Geopolymer is formed by activation of fine powder with pozzolanic properties with an alkali solution of sodium silicate (water glass). During geopolymerization, water acts primarily as a solvent, unlike the reactions during the setting of OPC, where hydration plays a key role. Various base materials, ranging from metakaolin to byproducts such as fly-ash and blast furnace slag, can be used. Coal fly-ash is an inexpensive raw material with low CO2 footprint (compared to OPC), with potential applications in radioactive waste conditioning. To our knowledge, the effect of ionizing radiation on geopolymer set time hasn’t been explored. We have measured the initial and final set time for fly-ash geopolymer paste, based on the SRPS EN 196-3 standard, irradiated by gamma rays in a Co-60 reference field on position with air kerma rate of 3.42 mGy/s. The binder paste was prepared using fly-ash from TENT B power plant’s electrostatic filters without further sieving, activated by water glass with module 1.5 and mixed with distilled water until satisfactory flow was obtained, and poured into sample and control molds. Initial and final set times for irradiated sample and non irradiated control were determined by Vicat apparatus. The irradiated sample demonstrated 11% shorter initial set time, and 16% shorter final set time, compared to control. These set times allow satisfactory working times for geopolymer grouts and mortars. The effect of ionizing radiation on set times and other properties of coal fly-ash based materials must be accounted for in all stages of application, from small scale testing and simulations, to full scale tests and production environments.",
publisher = "Niš : Sievert Association",
journal = "RAP 2019 : International conference on radiation applications : Book of abstracts",
title = "The effect of Co-60 gamma irradiation on coal fly-ash geopolymer set times",
pages = "62-62",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12138"
}

Rubinjoni, L., Stanković, S., Karadžić, K.,& Lončar, B.. (2019). The effect of Co-60 gamma irradiation on coal fly-ash geopolymer set times. in RAP 2019 : International conference on radiation applications : Book of abstracts
Niš : Sievert Association., 62-62.
https://hdl.handle.net/21.15107/rcub_vinar_12138

Rubinjoni L, Stanković S, Karadžić K, Lončar B. The effect of Co-60 gamma irradiation on coal fly-ash geopolymer set times. in RAP 2019 : International conference on radiation applications : Book of abstracts. 2019;:62-62.
https://hdl.handle.net/21.15107/rcub_vinar_12138 .

Rubinjoni, Luka, Stanković, Srboljub, Karadžić, Katarina, Lončar, Boris, "The effect of Co-60 gamma irradiation on coal fly-ash geopolymer set times" in RAP 2019 : International conference on radiation applications : Book of abstracts (2019):62-62,
https://hdl.handle.net/21.15107/rcub_vinar_12138 .

TY  - CONF
AU  - Živanović, Miloš
AU  - Lazarević, Đorđe
AU  - Ciraj-Bjelac, Olivera
AU  - Stanković, Srboljub
AU  - Ćeklić, Sandra M.
AU  - Karadžić, Katarina
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12346
AB  - Interkomparacije predstavljaju vaţnu aktivnost koja dokazuje da su usluge koje pruţaju laboratorije za etaloniranje u skladu sa meĊunarodno prihvaćenim standardima. U oblasti metrologije jonizujućeg zraĉenja, najĉešća su dva tipa interkomparacija – interkomparacije sa termoluminiscentnim dozimetrima i interkomparacije sa jonizacionim komorama ili drugim transfer instrumentima. U ovom radu su predstavljeni rezultati oba tipa interkomparacija u periodu od 2008. do 2014. godine. TakoĊe su analizirani rezultati interkomparacija i objašnjeno je na koji naĉin su otklonjeni uoĉeni problemi.
AB  - Intercomparisons are important activities performed to ensure that the services provided by calibration laboratories to end-users follow internationally accepted standards. Ionizing radiation dosimetry intercomparisons are usually of two types – postal thermoluminescent dosimeter intercomparisons and ionization chamber calibration intercomparisons. In this paper, both types of intercomparisons are discussed together with the results of 7 years of participation in such intercomparisons. Finally, several discrepancies were discovered as a result of intercomparisons analysis and the resolution of the discrepancies was discussed.
PB  - Beograd : Univerzitet u Beogradu, Institut za nuklearne nauke "Vinča"
PB  - Beograd : Društvo za zaštitu od zračenja Srbije i Crne Gore
C3  - 28. симпозијум ДЗЗСЦГ : зборник радова
T1  - Interkomparacije kao važan element osiguranja kvaliteta u metrologiji jonizujućeg zračenja
T1  - Intercomparisons as an important element of quality assurance in metrology of ionising radiation
SP  - 572
EP  - 576
UR  - https://hdl.handle.net/21.15107/rcub_vinar_12346
ER  - 

@conference{
author = "Živanović, Miloš and Lazarević, Đorđe and Ciraj-Bjelac, Olivera and Stanković, Srboljub and Ćeklić, Sandra M. and Karadžić, Katarina",
year = "2015",
abstract = "Interkomparacije predstavljaju vaţnu aktivnost koja dokazuje da su usluge koje pruţaju laboratorije za etaloniranje u skladu sa meĊunarodno prihvaćenim standardima. U oblasti metrologije jonizujućeg zraĉenja, najĉešća su dva tipa interkomparacija – interkomparacije sa termoluminiscentnim dozimetrima i interkomparacije sa jonizacionim komorama ili drugim transfer instrumentima. U ovom radu su predstavljeni rezultati oba tipa interkomparacija u periodu od 2008. do 2014. godine. TakoĊe su analizirani rezultati interkomparacija i objašnjeno je na koji naĉin su otklonjeni uoĉeni problemi., Intercomparisons are important activities performed to ensure that the services provided by calibration laboratories to end-users follow internationally accepted standards. Ionizing radiation dosimetry intercomparisons are usually of two types – postal thermoluminescent dosimeter intercomparisons and ionization chamber calibration intercomparisons. In this paper, both types of intercomparisons are discussed together with the results of 7 years of participation in such intercomparisons. Finally, several discrepancies were discovered as a result of intercomparisons analysis and the resolution of the discrepancies was discussed.",
publisher = "Beograd : Univerzitet u Beogradu, Institut za nuklearne nauke "Vinča", Beograd : Društvo za zaštitu od zračenja Srbije i Crne Gore",
journal = "28. симпозијум ДЗЗСЦГ : зборник радова",
title = "Interkomparacije kao važan element osiguranja kvaliteta u metrologiji jonizujućeg zračenja, Intercomparisons as an important element of quality assurance in metrology of ionising radiation",
pages = "572-576",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12346"
}

Živanović, M., Lazarević, Đ., Ciraj-Bjelac, O., Stanković, S., Ćeklić, S. M.,& Karadžić, K.. (2015). Interkomparacije kao važan element osiguranja kvaliteta u metrologiji jonizujućeg zračenja. in 28. симпозијум ДЗЗСЦГ : зборник радова
Beograd : Univerzitet u Beogradu, Institut za nuklearne nauke "Vinča"., 572-576.
https://hdl.handle.net/21.15107/rcub_vinar_12346

Živanović M, Lazarević Đ, Ciraj-Bjelac O, Stanković S, Ćeklić SM, Karadžić K. Interkomparacije kao važan element osiguranja kvaliteta u metrologiji jonizujućeg zračenja. in 28. симпозијум ДЗЗСЦГ : зборник радова. 2015;:572-576.
https://hdl.handle.net/21.15107/rcub_vinar_12346 .

Živanović, Miloš, Lazarević, Đorđe, Ciraj-Bjelac, Olivera, Stanković, Srboljub, Ćeklić, Sandra M., Karadžić, Katarina, "Interkomparacije kao važan element osiguranja kvaliteta u metrologiji jonizujućeg zračenja" in 28. симпозијум ДЗЗСЦГ : зборник радова (2015):572-576,
https://hdl.handle.net/21.15107/rcub_vinar_12346 .

TY  - CONF
AU  - Stanković, Srboljub
AU  - Jakšić, Aleksandar
AU  - Ilić, Radovan
AU  - Nikolić, Dragana
AU  - Lončar, Boris
AU  - Lazarević, Đorđe
AU  - Karadžić, Katarina
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12151
AB  - MOSFET electronic components are already the subject of several decades of research in various fields of dosimetry and radiation protection. Special interest appeared when these components are started to be used as dosimeters in radiotherapy with electron beams. However, if one looks much more serious in the wider scientific research horizon, all the results obtained in experiments with precisely defined energies of incident electrons can be used in other disciplines which consider the impacts spectra of cosmic radiation on electronic devices, which is especially importance for cosmic science and space research instrumentation. In this paper, one of the objectives was to examine the electrical characteristics specially designed ESAPMOS RADFET dosimeters in the experiments that were conducted on a linear accelerator installations. RADFET components are bombarded electron beams energy of 6 MeV and 8 MeV, and then are followed by changes in threshold voltage shift mean values depending on the change of absorbed dose is referred to as D(cGy) was determined in water. Conclusions performance RADFET components are more than encouraging in terms of further research to improve the linearity of the energy dependence as widely energy electrons. In the second part of the test complex structure of packaging components RADFET focus is placed on the determination of the energy deposited in layers that are of interest for the analysis of microscopic processes related to the recombination of radiation-induced electron-hole pairs. Transport incident electrons through all the layers of structure RADFET component type ESAPMOS was carried out numerical simulations of the Monte Carlo method using the software package FOTELP-2K12. On this occasion, were taken into account all the physical processes of interaction of electrons with materials given structure. When he conquered the numerical application of mathematical and physical model for determining the value of the absorbed energy as the energy deposited per unit mass in a given layers with different materials, it could be accessed defining physical shielding factor (PSF) for a given structure RADFET components. Physical shielding factor (PSF) is defined as the ratio of absorbed dose values, which in fact means that it is equal to the energy deposited when the RADFET is shielded with protection, and the RADFET without lid. When we know the energy dependence factor for PSF of RADFET with and without armour, can be carried out and the analysis of whether and to what extent the energy required compensating the electronic components. Monte Carlo simulations were performed for the transport of incident electrons from 4 MeV, 6 MeV, 8 MeV and 12 MeV. It can be concluded that the different energy of incident electrons there is a significant influence of material Kovar on the absorbed energy in SiO2 and Si layers structure RADFET, in cases where Kovar used among other things as physical protection.
PB  - Niš : RAD Association
C3  - RAD 2015 : International Conference on Radiation and Applications in Various Fields of Research : Book of abstracts
T1  - Experiments with RADFET dosimeter in electron-beams irradiation and numerical computation of the physical shielding factor
SP  - 153
EP  - 153
UR  - https://hdl.handle.net/21.15107/rcub_vinar_12151
ER  - 

@conference{
author = "Stanković, Srboljub and Jakšić, Aleksandar and Ilić, Radovan and Nikolić, Dragana and Lončar, Boris and Lazarević, Đorđe and Karadžić, Katarina",
year = "2015",
abstract = "MOSFET electronic components are already the subject of several decades of research in various fields of dosimetry and radiation protection. Special interest appeared when these components are started to be used as dosimeters in radiotherapy with electron beams. However, if one looks much more serious in the wider scientific research horizon, all the results obtained in experiments with precisely defined energies of incident electrons can be used in other disciplines which consider the impacts spectra of cosmic radiation on electronic devices, which is especially importance for cosmic science and space research instrumentation. In this paper, one of the objectives was to examine the electrical characteristics specially designed ESAPMOS RADFET dosimeters in the experiments that were conducted on a linear accelerator installations. RADFET components are bombarded electron beams energy of 6 MeV and 8 MeV, and then are followed by changes in threshold voltage shift mean values depending on the change of absorbed dose is referred to as D(cGy) was determined in water. Conclusions performance RADFET components are more than encouraging in terms of further research to improve the linearity of the energy dependence as widely energy electrons. In the second part of the test complex structure of packaging components RADFET focus is placed on the determination of the energy deposited in layers that are of interest for the analysis of microscopic processes related to the recombination of radiation-induced electron-hole pairs. Transport incident electrons through all the layers of structure RADFET component type ESAPMOS was carried out numerical simulations of the Monte Carlo method using the software package FOTELP-2K12. On this occasion, were taken into account all the physical processes of interaction of electrons with materials given structure. When he conquered the numerical application of mathematical and physical model for determining the value of the absorbed energy as the energy deposited per unit mass in a given layers with different materials, it could be accessed defining physical shielding factor (PSF) for a given structure RADFET components. Physical shielding factor (PSF) is defined as the ratio of absorbed dose values, which in fact means that it is equal to the energy deposited when the RADFET is shielded with protection, and the RADFET without lid. When we know the energy dependence factor for PSF of RADFET with and without armour, can be carried out and the analysis of whether and to what extent the energy required compensating the electronic components. Monte Carlo simulations were performed for the transport of incident electrons from 4 MeV, 6 MeV, 8 MeV and 12 MeV. It can be concluded that the different energy of incident electrons there is a significant influence of material Kovar on the absorbed energy in SiO2 and Si layers structure RADFET, in cases where Kovar used among other things as physical protection.",
publisher = "Niš : RAD Association",
journal = "RAD 2015 : International Conference on Radiation and Applications in Various Fields of Research : Book of abstracts",
title = "Experiments with RADFET dosimeter in electron-beams irradiation and numerical computation of the physical shielding factor",
pages = "153-153",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12151"
}

Stanković, S., Jakšić, A., Ilić, R., Nikolić, D., Lončar, B., Lazarević, Đ.,& Karadžić, K.. (2015). Experiments with RADFET dosimeter in electron-beams irradiation and numerical computation of the physical shielding factor. in RAD 2015 : International Conference on Radiation and Applications in Various Fields of Research : Book of abstracts
Niš : RAD Association., 153-153.
https://hdl.handle.net/21.15107/rcub_vinar_12151

Stanković S, Jakšić A, Ilić R, Nikolić D, Lončar B, Lazarević Đ, Karadžić K. Experiments with RADFET dosimeter in electron-beams irradiation and numerical computation of the physical shielding factor. in RAD 2015 : International Conference on Radiation and Applications in Various Fields of Research : Book of abstracts. 2015;:153-153.
https://hdl.handle.net/21.15107/rcub_vinar_12151 .

Stanković, Srboljub, Jakšić, Aleksandar, Ilić, Radovan, Nikolić, Dragana, Lončar, Boris, Lazarević, Đorđe, Karadžić, Katarina, "Experiments with RADFET dosimeter in electron-beams irradiation and numerical computation of the physical shielding factor" in RAD 2015 : International Conference on Radiation and Applications in Various Fields of Research : Book of abstracts (2015):153-153,
https://hdl.handle.net/21.15107/rcub_vinar_12151 .