Obradović, Nina

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Authority KeyName Variants
orcid::0000-0002-7993-293X
  • Obradović, Nina (184)
  • Obradović, Nina N. (1)
Projects
Directed synthesis, structure and properties of multifunctional materials Investigation of the relation in triad: Synthesis structure-properties for functional materials
Ministry of Education, Science and Technological Development, Republic of Serbia, Grant no. 451-03-68/2020-14/200175 (Institute of Technical Sciences of SASA, Belgrade) Ministry of Education, Youth and Sports (MEYS) of Czech Republic - CEITEC 2020 [LQ1601]
Development and application of multifunctional materials using domestic raw materials in upgraded processing lines United States National Aeronautics and Space Administration (NASA), Grant NNX09AV07A
Serbian Academy of Sciences and Arts, Project F-198 Synthesis, processing and applications of nanostructured multifunctional materials with defined properties
Algorithms and software for frequency-domain and time-domain simulations of RF subsystems and electromagnetic sensors in ICT Serbian Academy of Sciences and Arts, Project F-133
United States National Science Foundation (NSF) / Centers of Research Excellence in Science and Technology (CREST), Grant HRD-0833184 United States National Science Foundation (NSF) / Partnerships for Research and Education in Materials (PREM), Grant 1523617
Bilateral cooperation between Serbia and France, No. 4510339/2016/09/03 “Inteligent econanomaterials and nanocomposites” Grant Agency of the Czech Republic, Project 15-06390S
Ministry of Education, Science and Technological Development, Republic of Serbia, Grant no. 451-03-68/2020-14/200026 (University of Belgrade, Institute of Chemistry, Technology and Metallurgy - IChTM) Zero- to Three-Dimensional Nanostructures for Application in Electronics and Renewable Energy Sources: Synthesis, Characterization and Processing
National Science Foundation, North Carolina State University, Project No. HRD-1345219 Czech Science Foundation (GACR) - 17-05620S
Investigation of intermetallics and semiconductors and possible application in renewable energy sources Geologic and ecotoxicologic research in identification of geopathogen zones of toxic elements in drinking water reservoirs- research into methods and procedures for reduction of biochemical anomalies
Brno University of Technology - BUT Internal Projects: STI-J-18-5456, Czechia CEITEC Nano RI, MEYS CR, 2016–2019
CONACYT grant 2018-000022-01EXTV-00188, Mexico DAAD scholarship project "Development of materials and manufacturing technologies for electric discharge machinable Zirconia–CNT/Graphene composites"
Ministry of Education, Science and Technological Development, Republic of Serbia, Grant no. 451-03-68/2020-14/200023 (Institute of Technology of Nuclear and Other Mineral Row Materials - ITNMS, Belgrade) Ministry of Education, Science and Technological Development, Republic of Serbia, Grant no. 451-03-68/2020-14/200131 (University of Belgrade, Technical Faculty, Bor)
Innovative electronic components and systems based on inorganic and organic technologies embedded in consumer goods and products Serbian Academy of Sciences and Arts, Project F-7/II
Austrian Federal Funding Agency (FFG), MagnetoPIM (programme CIR-CE - Cooperation in Innovation and Research with Central and Eastern Europe) European Regional Development Fund through a project CEITEC, CZ.1.05/1.1.00/02.0068

Author's Bibliography

Removal of the As(V) and Cr(VI) from the Water Using Magnetite/3D-Printed Wollastonite Hybrid Adsorbent

Popović, Mina; Veličković, Zlate S.; Bogdanov, Jovica; Marinković, Aleksandar D.; Luna, Mariano Casas; Trajković, Isaak; Obradović, Nina; Pavlović, Vladimir B.

(International Institute for the Science of Sintering (IISS), 2022)

TY  - JOUR
AU  - Popović, Mina
AU  - Veličković, Zlate S.
AU  - Bogdanov, Jovica
AU  - Marinković, Aleksandar D.
AU  - Luna, Mariano Casas
AU  - Trajković, Isaak
AU  - Obradović, Nina
AU  - Pavlović, Vladimir B.
PY  - 2022
UR  - https://dais.sanu.ac.rs/123456789/12955
AB  - In this study, the structure, morphology and composition of the synthesized magnetite/3D-printed wollastonite (3D_W/M) composite were characterized, and its adsorption performance with respect to As(V) and Cr(VI) were studied. Magnetite (MG) modified 3D printed wollastonite was obtained by two step procedure: modification of 3D_W with 3-aminoproylsilane (APTES) followed by controlled magnetite (MG) deposition to obtain 3D_W/M adsorbent. The structure/properties of 3D_W/M were confirmed by applying FTIR, XRD, TGD/DTA, and SEM analysis. The adsorption properties of hybrid adsorbents were carried out for As(V) and Cr(VI) removal-one relative to the initial pH value, the adsorbent mass, the temperature, and the adsorption time. Time-dependent adsorption study was best described by pseudo-second order equation, while Weber Morris analysis showed that intraparticle diffusion controled diffusional transport. Similar activation energy, 17.44 and 14.49 kJ•mol-1 for adsorption As(V) and Cr(VI) on 3D_W/M, respectively, indicated main contribution of physical adsorption. Determination of adsorption parameters was performed by applying different adsorption isotherm models, and the best fit was obtained using Freundlich model. The adsorption capacity of 24.16 and 29.6 mg g-1 for As(V) and Cr(VI) at 2o C, Co = 5.5 and 5.3 mg L-1, respectively, were obtained. Thermodynamic study indicated favourable process at a higher temperature. Preliminary fixed-bed column study and results fitting with Bohart-Adams, Yoon-Nelson, Thomas, and Modified dose-response model showed good agreement with results from the batch study.
PB  - International Institute for the Science of Sintering (IISS)
T2  - Science of Sintering
T1  - Removal of the As(V) and Cr(VI) from the Water Using Magnetite/3D-Printed Wollastonite Hybrid Adsorbent
SP  - 105
EP  - 124
VL  - 54
IS  - 1
DO  - 10.2298/SOS2201105P
UR  - https://hdl.handle.net/21.15107/rcub_dais_12955
ER  - 
@article{
author = "Popović, Mina and Veličković, Zlate S. and Bogdanov, Jovica and Marinković, Aleksandar D. and Luna, Mariano Casas and Trajković, Isaak and Obradović, Nina and Pavlović, Vladimir B.",
year = "2022",
abstract = "In this study, the structure, morphology and composition of the synthesized magnetite/3D-printed wollastonite (3D_W/M) composite were characterized, and its adsorption performance with respect to As(V) and Cr(VI) were studied. Magnetite (MG) modified 3D printed wollastonite was obtained by two step procedure: modification of 3D_W with 3-aminoproylsilane (APTES) followed by controlled magnetite (MG) deposition to obtain 3D_W/M adsorbent. The structure/properties of 3D_W/M were confirmed by applying FTIR, XRD, TGD/DTA, and SEM analysis. The adsorption properties of hybrid adsorbents were carried out for As(V) and Cr(VI) removal-one relative to the initial pH value, the adsorbent mass, the temperature, and the adsorption time. Time-dependent adsorption study was best described by pseudo-second order equation, while Weber Morris analysis showed that intraparticle diffusion controled diffusional transport. Similar activation energy, 17.44 and 14.49 kJ•mol-1 for adsorption As(V) and Cr(VI) on 3D_W/M, respectively, indicated main contribution of physical adsorption. Determination of adsorption parameters was performed by applying different adsorption isotherm models, and the best fit was obtained using Freundlich model. The adsorption capacity of 24.16 and 29.6 mg g-1 for As(V) and Cr(VI) at 2o C, Co = 5.5 and 5.3 mg L-1, respectively, were obtained. Thermodynamic study indicated favourable process at a higher temperature. Preliminary fixed-bed column study and results fitting with Bohart-Adams, Yoon-Nelson, Thomas, and Modified dose-response model showed good agreement with results from the batch study.",
publisher = "International Institute for the Science of Sintering (IISS)",
journal = "Science of Sintering",
title = "Removal of the As(V) and Cr(VI) from the Water Using Magnetite/3D-Printed Wollastonite Hybrid Adsorbent",
pages = "105-124",
volume = "54",
number = "1",
doi = "10.2298/SOS2201105P",
url = "https://hdl.handle.net/21.15107/rcub_dais_12955"
}
Popović, M., Veličković, Z. S., Bogdanov, J., Marinković, A. D., Luna, M. C., Trajković, I., Obradović, N.,& Pavlović, V. B.. (2022). Removal of the As(V) and Cr(VI) from the Water Using Magnetite/3D-Printed Wollastonite Hybrid Adsorbent. in Science of Sintering
International Institute for the Science of Sintering (IISS)., 54(1), 105-124.
https://doi.org/10.2298/SOS2201105P
https://hdl.handle.net/21.15107/rcub_dais_12955
Popović M, Veličković ZS, Bogdanov J, Marinković AD, Luna MC, Trajković I, Obradović N, Pavlović VB. Removal of the As(V) and Cr(VI) from the Water Using Magnetite/3D-Printed Wollastonite Hybrid Adsorbent. in Science of Sintering. 2022;54(1):105-124.
doi:10.2298/SOS2201105P
https://hdl.handle.net/21.15107/rcub_dais_12955 .
Popović, Mina, Veličković, Zlate S., Bogdanov, Jovica, Marinković, Aleksandar D., Luna, Mariano Casas, Trajković, Isaak, Obradović, Nina, Pavlović, Vladimir B., "Removal of the As(V) and Cr(VI) from the Water Using Magnetite/3D-Printed Wollastonite Hybrid Adsorbent" in Science of Sintering, 54, no. 1 (2022):105-124,
https://doi.org/10.2298/SOS2201105P .,
https://hdl.handle.net/21.15107/rcub_dais_12955 .

Structural And Functional Investigation Of Fe/Pb/Zr-co-doped Barium Titanate Ceramics: From Theory To The Experiment

Stojanović, Nemanja; Zagorac, Dejan; Butulija, Svetlana; Lojpur, Vesna; Kalezić-Glišović, Aleksandra; Obradović, Nina; Maričić, Aleksa

(Belgrade : Serbian Ceramic Society, 2021)

TY  - CONF
AU  - Stojanović, Nemanja
AU  - Zagorac, Dejan
AU  - Butulija, Svetlana
AU  - Lojpur, Vesna
AU  - Kalezić-Glišović, Aleksandra
AU  - Obradović, Nina
AU  - Maričić, Aleksa
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/11898
AB  - Mixtures of high purity powders of 50 mass% Fe, 4 mass% Pb, 3 mass% Zr and 43 mass% BaTiO3 were activated in a rotary ball mill for durations ranging from 30 min to 300 min; samples were then sintered in the air atmosphere for 2 hours at 1200 °C. Crystal structure prediction has been performed using Bond ValenceCalculation (BVC) method.Moreover, theoretical stability of theperovskite structure for synthesized and calculated Fe/Pb/Zr-codoped barium titanatecompounds has been investigated using the Goldschmidttolerance factor (Gt) and global instability index (GII).It was observed that magnetization of the system decreased after the sintering, with the most dramatic drop of 90.11% belonging to the sample activated for 150 min. In comparison with initial powders, X-ray powder diffractiondata confirmed the presence of newphases of BaFe12O19 and Ba1.696Ti0.228O3 in sintered samples. Utilizing the field emission scanning electron microscopy (FESEM), it was found that with the increase of activation time the morphology of the samples progressed from irregural, spherical grains to mostly rod-like ones. Energy dispersive X-ray (EDX) analysis identified the presence of Pb and Zr occupying the same locations on the surface of sintered samples, whilst Fe was uniformly deployed regardless of the activation time.
PB  - Belgrade : Serbian Ceramic Society
C3  - Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application IX : New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 20-21. September 2021
T1  - Structural And Functional Investigation Of Fe/Pb/Zr-co-doped Barium Titanate Ceramics: From Theory To The Experiment
SP  - 77
EP  - 77
UR  - https://hdl.handle.net/21.15107/rcub_dais_11898
ER  - 
@conference{
author = "Stojanović, Nemanja and Zagorac, Dejan and Butulija, Svetlana and Lojpur, Vesna and Kalezić-Glišović, Aleksandra and Obradović, Nina and Maričić, Aleksa",
year = "2021",
abstract = "Mixtures of high purity powders of 50 mass% Fe, 4 mass% Pb, 3 mass% Zr and 43 mass% BaTiO3 were activated in a rotary ball mill for durations ranging from 30 min to 300 min; samples were then sintered in the air atmosphere for 2 hours at 1200 °C. Crystal structure prediction has been performed using Bond ValenceCalculation (BVC) method.Moreover, theoretical stability of theperovskite structure for synthesized and calculated Fe/Pb/Zr-codoped barium titanatecompounds has been investigated using the Goldschmidttolerance factor (Gt) and global instability index (GII).It was observed that magnetization of the system decreased after the sintering, with the most dramatic drop of 90.11% belonging to the sample activated for 150 min. In comparison with initial powders, X-ray powder diffractiondata confirmed the presence of newphases of BaFe12O19 and Ba1.696Ti0.228O3 in sintered samples. Utilizing the field emission scanning electron microscopy (FESEM), it was found that with the increase of activation time the morphology of the samples progressed from irregural, spherical grains to mostly rod-like ones. Energy dispersive X-ray (EDX) analysis identified the presence of Pb and Zr occupying the same locations on the surface of sintered samples, whilst Fe was uniformly deployed regardless of the activation time.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application IX : New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 20-21. September 2021",
title = "Structural And Functional Investigation Of Fe/Pb/Zr-co-doped Barium Titanate Ceramics: From Theory To The Experiment",
pages = "77-77",
url = "https://hdl.handle.net/21.15107/rcub_dais_11898"
}
Stojanović, N., Zagorac, D., Butulija, S., Lojpur, V., Kalezić-Glišović, A., Obradović, N.,& Maričić, A.. (2021). Structural And Functional Investigation Of Fe/Pb/Zr-co-doped Barium Titanate Ceramics: From Theory To The Experiment. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application IX : New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 20-21. September 2021
Belgrade : Serbian Ceramic Society., 77-77.
https://hdl.handle.net/21.15107/rcub_dais_11898
Stojanović N, Zagorac D, Butulija S, Lojpur V, Kalezić-Glišović A, Obradović N, Maričić A. Structural And Functional Investigation Of Fe/Pb/Zr-co-doped Barium Titanate Ceramics: From Theory To The Experiment. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application IX : New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 20-21. September 2021. 2021;:77-77.
https://hdl.handle.net/21.15107/rcub_dais_11898 .
Stojanović, Nemanja, Zagorac, Dejan, Butulija, Svetlana, Lojpur, Vesna, Kalezić-Glišović, Aleksandra, Obradović, Nina, Maričić, Aleksa, "Structural And Functional Investigation Of Fe/Pb/Zr-co-doped Barium Titanate Ceramics: From Theory To The Experiment" in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application IX : New Frontiers in Multifunctional Material Science and Processing, Serbia, Belgrade, 20-21. September 2021 (2021):77-77,
https://hdl.handle.net/21.15107/rcub_dais_11898 .

Multiferroic Heterostructure BaTiO3/ε-Fe2O3 Composite Obtained by in situ Reaction

Filipović, Suzana; Obradović, Nina; Anđelković, Ljubica; Olćan, Dragan; Petrović, Jovana; Mirković, Miljana; Pavlović, Vladimir B.; Jeremić, Dejan; Vlahović, Branislav; Đorđević, Antonije

(Belgrade : International Institute for the Science of Sintering, 2021)

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Anđelković, Ljubica
AU  - Olćan, Dragan
AU  - Petrović, Jovana
AU  - Mirković, Miljana
AU  - Pavlović, Vladimir B.
AU  - Jeremić, Dejan
AU  - Vlahović, Branislav
AU  - Đorđević, Antonije
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/11230
AB  - Solid-state reaction between BaTiO3 and Fe2O3 was used to produce a multiferroic heterostructure composite. Commercial BaTiO3 and Fe(NO3)3•9H2O were suspended in ethanol for 30 minutes in an ultrasound bath. The prepared mixture was thermally processed at 300 oC for 6 h. Sintering at 1300 oC for 1 h resulted in a mixture of different phases, BaTiO3, BaFe12O19 and Ba12Ti28Fe15O84, which were confirmed by x-ray powder diffraction. A dense microstructure with a small volume fraction of closed porosity was indicated by the scanning electron microscopy, while a homogeneous distribution of Fe ions over BaTiO3 phase was visible from energy dispersive spectroscopy mapping. Doping of BaTiO3 with Fe2O3 resulted in formation of magnetic hexaferrite phases, as confirmed by dielectric measurements that showed a broadened maximum of the permittivity measured as a function of temperature.
PB  - Belgrade : International Institute for the Science of Sintering
T2  - Science of Sintering
T1  - Multiferroic Heterostructure BaTiO3/ε-Fe2O3 Composite Obtained by in situ Reaction
SP  - 1
EP  - 8
VL  - 53
DO  - 10.2298/SOS2101001F
UR  - https://hdl.handle.net/21.15107/rcub_dais_11230
ER  - 
@article{
author = "Filipović, Suzana and Obradović, Nina and Anđelković, Ljubica and Olćan, Dragan and Petrović, Jovana and Mirković, Miljana and Pavlović, Vladimir B. and Jeremić, Dejan and Vlahović, Branislav and Đorđević, Antonije",
year = "2021",
abstract = "Solid-state reaction between BaTiO3 and Fe2O3 was used to produce a multiferroic heterostructure composite. Commercial BaTiO3 and Fe(NO3)3•9H2O were suspended in ethanol for 30 minutes in an ultrasound bath. The prepared mixture was thermally processed at 300 oC for 6 h. Sintering at 1300 oC for 1 h resulted in a mixture of different phases, BaTiO3, BaFe12O19 and Ba12Ti28Fe15O84, which were confirmed by x-ray powder diffraction. A dense microstructure with a small volume fraction of closed porosity was indicated by the scanning electron microscopy, while a homogeneous distribution of Fe ions over BaTiO3 phase was visible from energy dispersive spectroscopy mapping. Doping of BaTiO3 with Fe2O3 resulted in formation of magnetic hexaferrite phases, as confirmed by dielectric measurements that showed a broadened maximum of the permittivity measured as a function of temperature.",
publisher = "Belgrade : International Institute for the Science of Sintering",
journal = "Science of Sintering",
title = "Multiferroic Heterostructure BaTiO3/ε-Fe2O3 Composite Obtained by in situ Reaction",
pages = "1-8",
volume = "53",
doi = "10.2298/SOS2101001F",
url = "https://hdl.handle.net/21.15107/rcub_dais_11230"
}
Filipović, S., Obradović, N., Anđelković, L., Olćan, D., Petrović, J., Mirković, M., Pavlović, V. B., Jeremić, D., Vlahović, B.,& Đorđević, A.. (2021). Multiferroic Heterostructure BaTiO3/ε-Fe2O3 Composite Obtained by in situ Reaction. in Science of Sintering
Belgrade : International Institute for the Science of Sintering., 53, 1-8.
https://doi.org/10.2298/SOS2101001F
https://hdl.handle.net/21.15107/rcub_dais_11230
Filipović S, Obradović N, Anđelković L, Olćan D, Petrović J, Mirković M, Pavlović VB, Jeremić D, Vlahović B, Đorđević A. Multiferroic Heterostructure BaTiO3/ε-Fe2O3 Composite Obtained by in situ Reaction. in Science of Sintering. 2021;53:1-8.
doi:10.2298/SOS2101001F
https://hdl.handle.net/21.15107/rcub_dais_11230 .
Filipović, Suzana, Obradović, Nina, Anđelković, Ljubica, Olćan, Dragan, Petrović, Jovana, Mirković, Miljana, Pavlović, Vladimir B., Jeremić, Dejan, Vlahović, Branislav, Đorđević, Antonije, "Multiferroic Heterostructure BaTiO3/ε-Fe2O3 Composite Obtained by in situ Reaction" in Science of Sintering, 53 (2021):1-8,
https://doi.org/10.2298/SOS2101001F .,
https://hdl.handle.net/21.15107/rcub_dais_11230 .
1
1

High-accuracy quasistatic numerical model for bodies of revolution tailored for RF measurements of dielectric parameters

Đorđević, Antonije; Olćan, Dragan; Petrović, Jovana; Obradović, Nina; Filipović, Suzana

(National Library of Serbia, 2021)

TY  - JOUR
AU  - Đorđević, Antonije
AU  - Olćan, Dragan
AU  - Petrović, Jovana
AU  - Obradović, Nina
AU  - Filipović, Suzana
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12341
AB  - We have developed rotationally symmetrical coaxial chambers for measurements of dielectric parameters of disk-shaped samples, in the frequency range from 1 MHz to several hundred MHz. The reflection coefficient of the chamber is measured and the dielectric parameters are hence extracted utilizing a high-accuracy quasistatic numerical model of the chamber and the sample. We present this model, which is based on the method-of-moments solution of a set of integral equations for composite metallic and dielectric bodies. The equations are tailored to bodies of revolution. The model is efficient and accurate so that the major contribution of the measurement uncertainty comes from the measurement hardware.
PB  - National Library of Serbia
T2  - Facta universitatis - series: Electronics and Energetics
T1  - High-accuracy quasistatic numerical model for bodies of revolution tailored for RF measurements of dielectric parameters
SP  - 141
EP  - 156
VL  - 34
IS  - 1
DO  - 10.2298/FUEE2101141D
UR  - https://hdl.handle.net/21.15107/rcub_dais_12341
ER  - 
@article{
author = "Đorđević, Antonije and Olćan, Dragan and Petrović, Jovana and Obradović, Nina and Filipović, Suzana",
year = "2021",
abstract = "We have developed rotationally symmetrical coaxial chambers for measurements of dielectric parameters of disk-shaped samples, in the frequency range from 1 MHz to several hundred MHz. The reflection coefficient of the chamber is measured and the dielectric parameters are hence extracted utilizing a high-accuracy quasistatic numerical model of the chamber and the sample. We present this model, which is based on the method-of-moments solution of a set of integral equations for composite metallic and dielectric bodies. The equations are tailored to bodies of revolution. The model is efficient and accurate so that the major contribution of the measurement uncertainty comes from the measurement hardware.",
publisher = "National Library of Serbia",
journal = "Facta universitatis - series: Electronics and Energetics",
title = "High-accuracy quasistatic numerical model for bodies of revolution tailored for RF measurements of dielectric parameters",
pages = "141-156",
volume = "34",
number = "1",
doi = "10.2298/FUEE2101141D",
url = "https://hdl.handle.net/21.15107/rcub_dais_12341"
}
Đorđević, A., Olćan, D., Petrović, J., Obradović, N.,& Filipović, S.. (2021). High-accuracy quasistatic numerical model for bodies of revolution tailored for RF measurements of dielectric parameters. in Facta universitatis - series: Electronics and Energetics
National Library of Serbia., 34(1), 141-156.
https://doi.org/10.2298/FUEE2101141D
https://hdl.handle.net/21.15107/rcub_dais_12341
Đorđević A, Olćan D, Petrović J, Obradović N, Filipović S. High-accuracy quasistatic numerical model for bodies of revolution tailored for RF measurements of dielectric parameters. in Facta universitatis - series: Electronics and Energetics. 2021;34(1):141-156.
doi:10.2298/FUEE2101141D
https://hdl.handle.net/21.15107/rcub_dais_12341 .
Đorđević, Antonije, Olćan, Dragan, Petrović, Jovana, Obradović, Nina, Filipović, Suzana, "High-accuracy quasistatic numerical model for bodies of revolution tailored for RF measurements of dielectric parameters" in Facta universitatis - series: Electronics and Energetics, 34, no. 1 (2021):141-156,
https://doi.org/10.2298/FUEE2101141D .,
https://hdl.handle.net/21.15107/rcub_dais_12341 .
1
1

Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions

Obradović, Nina; Fahrenholtz, William G.; Corlett, Cole; Filipović, Suzana; Nikolić, Marko; Marinković, Bojan A.; Failla, Simone; Sciti, Diletta; Di Rosa, Daniele; Sani, Elisa

(Basel : MDPI AG, 2021)

TY  - JOUR
AU  - Obradović, Nina
AU  - Fahrenholtz, William G.
AU  - Corlett, Cole
AU  - Filipović, Suzana
AU  - Nikolić, Marko
AU  - Marinković, Bojan A.
AU  - Failla, Simone
AU  - Sciti, Diletta
AU  - Di Rosa, Daniele
AU  - Sani, Elisa
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12431
AB  - Magnesium aluminate and other alumina-based spinels attract attention due to their high hardness, high mechanical strength, and low dielectric constant. MgAl2O4 was produced by a solid-state reaction between MgO and α-Al2O3 powders. Mechanical activation for 30 min in a planetary ball mill was used to increase the reactivity of powders. Yttrium oxide and graphene were added to prevent abnormal grain growth during sintering. Samples were sintered by hot pressing under vacuum at 1450 °C. Phase composition and microstructure of sintered specimens were characterized by X-ray powder diffraction and scanning electron microscopy. Rietveld analysis revealed 100% pure spinel phase in all sintered specimens, and a decrease in crystallite size with the addition of yttria or graphene. Density measurements indicated that the mechanically activated specimen reached 99.6% relative density. Furthermore, the highest solar absorbance and highest spectral selectivity as a function of temperature were detected for the mechanically activated specimen with graphene addition. Mechanical activation is an efficient method to improve densification of MgAl2O4 prepared from mixed oxide powders, while additives improve microstructure and optical properties.
PB  - Basel : MDPI AG
T2  - Materials
T1  - Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions
SP  - 7674
VL  - 14
IS  - 24
DO  - 10.3390/ma14247674
UR  - https://hdl.handle.net/21.15107/rcub_dais_12431
ER  - 
@article{
author = "Obradović, Nina and Fahrenholtz, William G. and Corlett, Cole and Filipović, Suzana and Nikolić, Marko and Marinković, Bojan A. and Failla, Simone and Sciti, Diletta and Di Rosa, Daniele and Sani, Elisa",
year = "2021",
abstract = "Magnesium aluminate and other alumina-based spinels attract attention due to their high hardness, high mechanical strength, and low dielectric constant. MgAl2O4 was produced by a solid-state reaction between MgO and α-Al2O3 powders. Mechanical activation for 30 min in a planetary ball mill was used to increase the reactivity of powders. Yttrium oxide and graphene were added to prevent abnormal grain growth during sintering. Samples were sintered by hot pressing under vacuum at 1450 °C. Phase composition and microstructure of sintered specimens were characterized by X-ray powder diffraction and scanning electron microscopy. Rietveld analysis revealed 100% pure spinel phase in all sintered specimens, and a decrease in crystallite size with the addition of yttria or graphene. Density measurements indicated that the mechanically activated specimen reached 99.6% relative density. Furthermore, the highest solar absorbance and highest spectral selectivity as a function of temperature were detected for the mechanically activated specimen with graphene addition. Mechanical activation is an efficient method to improve densification of MgAl2O4 prepared from mixed oxide powders, while additives improve microstructure and optical properties.",
publisher = "Basel : MDPI AG",
journal = "Materials",
title = "Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions",
pages = "7674",
volume = "14",
number = "24",
doi = "10.3390/ma14247674",
url = "https://hdl.handle.net/21.15107/rcub_dais_12431"
}
Obradović, N., Fahrenholtz, W. G., Corlett, C., Filipović, S., Nikolić, M., Marinković, B. A., Failla, S., Sciti, D., Di Rosa, D.,& Sani, E.. (2021). Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions. in Materials
Basel : MDPI AG., 14(24), 7674.
https://doi.org/10.3390/ma14247674
https://hdl.handle.net/21.15107/rcub_dais_12431
Obradović N, Fahrenholtz WG, Corlett C, Filipović S, Nikolić M, Marinković BA, Failla S, Sciti D, Di Rosa D, Sani E. Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions. in Materials. 2021;14(24):7674.
doi:10.3390/ma14247674
https://hdl.handle.net/21.15107/rcub_dais_12431 .
Obradović, Nina, Fahrenholtz, William G., Corlett, Cole, Filipović, Suzana, Nikolić, Marko, Marinković, Bojan A., Failla, Simone, Sciti, Diletta, Di Rosa, Daniele, Sani, Elisa, "Microstructural and Optical Properties of MgAl2O4 Spinel: Effects of Mechanical Activation, Y2O3 and Graphene Additions" in Materials, 14, no. 24 (2021):7674,
https://doi.org/10.3390/ma14247674 .,
https://hdl.handle.net/21.15107/rcub_dais_12431 .
3

High-Precision Method of Moments Applied to Measurement of Dielectric Parameters at Microwave Frequencies

Petrović, Jovana G.; Olćan, Dragan I.; Obradović, Nina N.; Đorđević, Antonije R.

(Institute of Electrical and Electronics Engineers (IEEE), 2021)

TY  - JOUR
AU  - Petrović, Jovana G.
AU  - Olćan, Dragan I.
AU  - Obradović, Nina N.
AU  - Đorđević, Antonije R.
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12534
AB  - A novel high-precision model of a custom-made coaxial chamber used for broadband measurement of the relative complex permittivity at microwave frequencies is presented. The model is based on a surface integral-equation formulation of the method of moments tailored for bodies of revolution. All singular integrals encountered in the numerical analysis are calculated in a unified way with a novel integral transformation, which enables the precision of up to 12 significant digits using the 64-bit representation of real numbers. The dielectric parameters are estimated from the reflection-coefficient measurement of the chamber with a disk-shaped dielectric sample by comparison of the measured data with the high-precision numerical analysis of the chamber. The complete measurement procedure is illustrated and verified using samples of known dielectric properties.
PB  - Institute of Electrical and Electronics Engineers (IEEE)
T2  - IEEE Transactions on Microwave Theory and Techniques
T1  - High-Precision Method of Moments Applied to Measurement of Dielectric Parameters at Microwave Frequencies
DO  - 10.1109/TMTT.2021.3136294
UR  - https://hdl.handle.net/21.15107/rcub_dais_12534
ER  - 
@article{
author = "Petrović, Jovana G. and Olćan, Dragan I. and Obradović, Nina N. and Đorđević, Antonije R.",
year = "2021",
abstract = "A novel high-precision model of a custom-made coaxial chamber used for broadband measurement of the relative complex permittivity at microwave frequencies is presented. The model is based on a surface integral-equation formulation of the method of moments tailored for bodies of revolution. All singular integrals encountered in the numerical analysis are calculated in a unified way with a novel integral transformation, which enables the precision of up to 12 significant digits using the 64-bit representation of real numbers. The dielectric parameters are estimated from the reflection-coefficient measurement of the chamber with a disk-shaped dielectric sample by comparison of the measured data with the high-precision numerical analysis of the chamber. The complete measurement procedure is illustrated and verified using samples of known dielectric properties.",
publisher = "Institute of Electrical and Electronics Engineers (IEEE)",
journal = "IEEE Transactions on Microwave Theory and Techniques",
title = "High-Precision Method of Moments Applied to Measurement of Dielectric Parameters at Microwave Frequencies",
doi = "10.1109/TMTT.2021.3136294",
url = "https://hdl.handle.net/21.15107/rcub_dais_12534"
}
Petrović, J. G., Olćan, D. I., Obradović, N. N.,& Đorđević, A. R.. (2021). High-Precision Method of Moments Applied to Measurement of Dielectric Parameters at Microwave Frequencies. in IEEE Transactions on Microwave Theory and Techniques
Institute of Electrical and Electronics Engineers (IEEE)..
https://doi.org/10.1109/TMTT.2021.3136294
https://hdl.handle.net/21.15107/rcub_dais_12534
Petrović JG, Olćan DI, Obradović NN, Đorđević AR. High-Precision Method of Moments Applied to Measurement of Dielectric Parameters at Microwave Frequencies. in IEEE Transactions on Microwave Theory and Techniques. 2021;.
doi:10.1109/TMTT.2021.3136294
https://hdl.handle.net/21.15107/rcub_dais_12534 .
Petrović, Jovana G., Olćan, Dragan I., Obradović, Nina N., Đorđević, Antonije R., "High-Precision Method of Moments Applied to Measurement of Dielectric Parameters at Microwave Frequencies" in IEEE Transactions on Microwave Theory and Techniques (2021),
https://doi.org/10.1109/TMTT.2021.3136294 .,
https://hdl.handle.net/21.15107/rcub_dais_12534 .

Electrical properties of isothermally sintered cordierite-based ceramics as function of sintering and activation time

Đorđević, Nataša; Peleš, Adriana; Obradović, Nina; Vlahović, Milica; Mihajlović, Slavica; Martinović, Sanja

(Beograd : Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS, 2021)

TY  - CONF
AU  - Đorđević, Nataša
AU  - Peleš, Adriana
AU  - Obradović, Nina
AU  - Vlahović, Milica
AU  - Mihajlović, Slavica
AU  - Martinović, Sanja
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12355
AB  - The mechanical activation of the starting mixtures of cordierite (2MgO*2Al2O3*5SiO2) with 5.00 mass % TiO2 was performed in a high energy ball mill during 10-80 min. The applied compaction pressure before the sintering process was 2t/cm2. The sintering process was performed at 1350°C for 2h and 4h in air atmosphere. Scanning electron microscopy was performed to analyze the microstructure of both compacted and sintered samples. Atomic force microscope was used to investigate the surface of the sintered samples. This paper investigates the influence of prolonged sintering time on the densities of the sintered samples, along with electrical properties.
AB  - Mehanička aktivacija početnih smeša kordierita (2MgO*2Al2O3*5SiO2) sa 5.00 mas. % TiO2 izvršena je u visokoenergetskom mlinu sa kuglama tokom 10-80 min. Primenjeni pritisak presovanja pre procesa sinterovanja bio je 2 t/cm2. Proces sinterovanja je izveden na 1350 °C tokom 2h i 4h u vazdušnoj atmosferi. Skenirajuća elektronska mikroskopija je izvršena u cilju analize mikrostrukture presovanih i sinterovanih uzoraka. Za ispitivanje površine sinterovanih uzoraka korišćen je mikroskop atomskih sila. Ovaj rad istražuje uticaj produženog vremena sinterovanja na gustinu sinterovanih uzoraka zajedno sa električnim svojstvima.
PB  - Beograd : Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS
C3  - Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021
T1  - Electrical properties of isothermally sintered cordierite-based ceramics as function of sintering and activation time
T1  - Električna svojstva izotermski sinterovane keramike na bazi kordierita kao funkcija vremena sinterovanja i aktivacije
SP  - 269
EP  - 272
UR  - https://hdl.handle.net/21.15107/rcub_dais_12355
ER  - 
@conference{
author = "Đorđević, Nataša and Peleš, Adriana and Obradović, Nina and Vlahović, Milica and Mihajlović, Slavica and Martinović, Sanja",
year = "2021",
abstract = "The mechanical activation of the starting mixtures of cordierite (2MgO*2Al2O3*5SiO2) with 5.00 mass % TiO2 was performed in a high energy ball mill during 10-80 min. The applied compaction pressure before the sintering process was 2t/cm2. The sintering process was performed at 1350°C for 2h and 4h in air atmosphere. Scanning electron microscopy was performed to analyze the microstructure of both compacted and sintered samples. Atomic force microscope was used to investigate the surface of the sintered samples. This paper investigates the influence of prolonged sintering time on the densities of the sintered samples, along with electrical properties., Mehanička aktivacija početnih smeša kordierita (2MgO*2Al2O3*5SiO2) sa 5.00 mas. % TiO2 izvršena je u visokoenergetskom mlinu sa kuglama tokom 10-80 min. Primenjeni pritisak presovanja pre procesa sinterovanja bio je 2 t/cm2. Proces sinterovanja je izveden na 1350 °C tokom 2h i 4h u vazdušnoj atmosferi. Skenirajuća elektronska mikroskopija je izvršena u cilju analize mikrostrukture presovanih i sinterovanih uzoraka. Za ispitivanje površine sinterovanih uzoraka korišćen je mikroskop atomskih sila. Ovaj rad istražuje uticaj produženog vremena sinterovanja na gustinu sinterovanih uzoraka zajedno sa električnim svojstvima.",
publisher = "Beograd : Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS",
journal = "Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021",
title = "Electrical properties of isothermally sintered cordierite-based ceramics as function of sintering and activation time, Električna svojstva izotermski sinterovane keramike na bazi kordierita kao funkcija vremena sinterovanja i aktivacije",
pages = "269-272",
url = "https://hdl.handle.net/21.15107/rcub_dais_12355"
}
Đorđević, N., Peleš, A., Obradović, N., Vlahović, M., Mihajlović, S.,& Martinović, S.. (2021). Electrical properties of isothermally sintered cordierite-based ceramics as function of sintering and activation time. in Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021
Beograd : Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS., 269-272.
https://hdl.handle.net/21.15107/rcub_dais_12355
Đorđević N, Peleš A, Obradović N, Vlahović M, Mihajlović S, Martinović S. Electrical properties of isothermally sintered cordierite-based ceramics as function of sintering and activation time. in Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021. 2021;:269-272.
https://hdl.handle.net/21.15107/rcub_dais_12355 .
Đorđević, Nataša, Peleš, Adriana, Obradović, Nina, Vlahović, Milica, Mihajlović, Slavica, Martinović, Sanja, "Electrical properties of isothermally sintered cordierite-based ceramics as function of sintering and activation time" in Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021 (2021):269-272,
https://hdl.handle.net/21.15107/rcub_dais_12355 .

Influence of sintering time on density properties and SEM analysis of cordierite-based ceramics

Đorđević, Nataša; Peleš, Adriana; Obradović, Nina; Vlahović, Milica; Mihajlović, Slavica; Martinović, Sanja

(Beograd : Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS, 2021)

TY  - CONF
AU  - Đorđević, Nataša
AU  - Peleš, Adriana
AU  - Obradović, Nina
AU  - Vlahović, Milica
AU  - Mihajlović, Slavica
AU  - Martinović, Sanja
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12354
AB  - The mechanical activation of the starting mixtures of cordierite (2MgO*2Al2O3*5SiO2) with 5.00 mass % TiO2 was performed in a high energy ball mill during 10-80 min. The applied compaction pressure before the sintering process was 2t/cm2. The sintering process was performed at 1350°C for 2h and 4h in air atmosphere. Scanning electron microscopy was performed to analyze the microstructure of both compacted and sintered samples. Atomic force microscope was used to investigate the surface of the sintered samples. This paper investigates the influence of prolonged sintering time on the densities of the sintered samples, along with electrical properties.
AB  - Mehanička aktivacija početnih smeša kordierita (2MgO*2Al2O3*5SiO2) sa 5.00 mas. % TiO2 izvršena je u visokoenergetskom mlinu sa kuglama tokom 10-80 min. Primenjeni pritisak presovanja pre procesa sinterovanja bio je 2 t/cm2. Proces sinterovanja je izveden na 1350 °C tokom 2h i 4h u vazdušnoj atmosferi. Skenirajuća elektronska mikroskopija je izvršena u cilju analize mikrostrukture presovanih i sinterovanih uzoraka. Za ispitivanje površine sinterovanih uzoraka korišćen je mikroskop atomskih sila. Ovaj rad istražuje uticaj produženog vremena sinterovanja na gustinu sinterovanih uzoraka zajedno sa električnim svojstvima.
PB  - Beograd : Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS
C3  - Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021
T1  - Influence of sintering time on density properties and SEM analysis of cordierite-based ceramics
T1  - Uticaj vremena sinterovanja na gustinu i SEM analiza kordijeritne keramike
SP  - 265
EP  - 268
UR  - https://hdl.handle.net/21.15107/rcub_dais_12354
ER  - 
@conference{
author = "Đorđević, Nataša and Peleš, Adriana and Obradović, Nina and Vlahović, Milica and Mihajlović, Slavica and Martinović, Sanja",
year = "2021",
abstract = "The mechanical activation of the starting mixtures of cordierite (2MgO*2Al2O3*5SiO2) with 5.00 mass % TiO2 was performed in a high energy ball mill during 10-80 min. The applied compaction pressure before the sintering process was 2t/cm2. The sintering process was performed at 1350°C for 2h and 4h in air atmosphere. Scanning electron microscopy was performed to analyze the microstructure of both compacted and sintered samples. Atomic force microscope was used to investigate the surface of the sintered samples. This paper investigates the influence of prolonged sintering time on the densities of the sintered samples, along with electrical properties., Mehanička aktivacija početnih smeša kordierita (2MgO*2Al2O3*5SiO2) sa 5.00 mas. % TiO2 izvršena je u visokoenergetskom mlinu sa kuglama tokom 10-80 min. Primenjeni pritisak presovanja pre procesa sinterovanja bio je 2 t/cm2. Proces sinterovanja je izveden na 1350 °C tokom 2h i 4h u vazdušnoj atmosferi. Skenirajuća elektronska mikroskopija je izvršena u cilju analize mikrostrukture presovanih i sinterovanih uzoraka. Za ispitivanje površine sinterovanih uzoraka korišćen je mikroskop atomskih sila. Ovaj rad istražuje uticaj produženog vremena sinterovanja na gustinu sinterovanih uzoraka zajedno sa električnim svojstvima.",
publisher = "Beograd : Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS",
journal = "Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021",
title = "Influence of sintering time on density properties and SEM analysis of cordierite-based ceramics, Uticaj vremena sinterovanja na gustinu i SEM analiza kordijeritne keramike",
pages = "265-268",
url = "https://hdl.handle.net/21.15107/rcub_dais_12354"
}
Đorđević, N., Peleš, A., Obradović, N., Vlahović, M., Mihajlović, S.,& Martinović, S.. (2021). Influence of sintering time on density properties and SEM analysis of cordierite-based ceramics. in Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021
Beograd : Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS., 265-268.
https://hdl.handle.net/21.15107/rcub_dais_12354
Đorđević N, Peleš A, Obradović N, Vlahović M, Mihajlović S, Martinović S. Influence of sintering time on density properties and SEM analysis of cordierite-based ceramics. in Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021. 2021;:265-268.
https://hdl.handle.net/21.15107/rcub_dais_12354 .
Đorđević, Nataša, Peleš, Adriana, Obradović, Nina, Vlahović, Milica, Mihajlović, Slavica, Martinović, Sanja, "Influence of sintering time on density properties and SEM analysis of cordierite-based ceramics" in Zbornik radova / 9. Međunarodna konferencija o obnovljivim izvorima električne energije, Beograd, 15. oktobar 2021 = Proceedings / 9th International Conference on Renewable Electrical Power Sources, Belgrade, October 15, 2021 (2021):265-268,
https://hdl.handle.net/21.15107/rcub_dais_12354 .

Preparation and characterization of ZrB2-TiB2 based composites for hypersonic systems

Obradović, Nina; Filipović, Suzana; Gilli, N.; Silvestroni, L.

(Belgrade : Innovation Center of Faculty of Mechanical Engineering, 2021)

TY  - CONF
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Gilli, N.
AU  - Silvestroni, L.
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12352
AB  - ZrB2 ceramics are considered potential materials for hypersonic systems in view of the melting point exceeding 3000 °C and excellent ablation resistance. Second phases, including SiC or CrB2, further improve the oxidation behavior, whereas a lighter phase, like TiB2 can decrease the overall weight. In this work, a powder mixture containing ZrB2, TiB2, CrB2 and SiC was mechanically activated using high energy ball-milling. Sintering was performed by hot pressing following different thermal cycles, and subsequent annealing to remove oxide phases and reduce micro-cracking. The microstructure and hardness of the dense ceramics are compared in relationship to the thermal history. Fully dense ceramics were obtained with different oxide-phases amount depending on the sintering cycle and hardness approaching 24 GPa were achieved. Future works will explore the strength and oxidation resistance of this multi-phase system to check its suitability for hypersonic systems.
PB  - Belgrade : Innovation Center of Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia
T1  - Preparation and characterization of ZrB2-TiB2 based composites for hypersonic systems
SP  - 83
EP  - 83
UR  - https://hdl.handle.net/21.15107/rcub_dais_12352
ER  - 
@conference{
author = "Obradović, Nina and Filipović, Suzana and Gilli, N. and Silvestroni, L.",
year = "2021",
abstract = "ZrB2 ceramics are considered potential materials for hypersonic systems in view of the melting point exceeding 3000 °C and excellent ablation resistance. Second phases, including SiC or CrB2, further improve the oxidation behavior, whereas a lighter phase, like TiB2 can decrease the overall weight. In this work, a powder mixture containing ZrB2, TiB2, CrB2 and SiC was mechanically activated using high energy ball-milling. Sintering was performed by hot pressing following different thermal cycles, and subsequent annealing to remove oxide phases and reduce micro-cracking. The microstructure and hardness of the dense ceramics are compared in relationship to the thermal history. Fully dense ceramics were obtained with different oxide-phases amount depending on the sintering cycle and hardness approaching 24 GPa were achieved. Future works will explore the strength and oxidation resistance of this multi-phase system to check its suitability for hypersonic systems.",
publisher = "Belgrade : Innovation Center of Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia",
title = "Preparation and characterization of ZrB2-TiB2 based composites for hypersonic systems",
pages = "83-83",
url = "https://hdl.handle.net/21.15107/rcub_dais_12352"
}
Obradović, N., Filipović, S., Gilli, N.,& Silvestroni, L.. (2021). Preparation and characterization of ZrB2-TiB2 based composites for hypersonic systems. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia
Belgrade : Innovation Center of Faculty of Mechanical Engineering., 83-83.
https://hdl.handle.net/21.15107/rcub_dais_12352
Obradović N, Filipović S, Gilli N, Silvestroni L. Preparation and characterization of ZrB2-TiB2 based composites for hypersonic systems. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia. 2021;:83-83.
https://hdl.handle.net/21.15107/rcub_dais_12352 .
Obradović, Nina, Filipović, Suzana, Gilli, N., Silvestroni, L., "Preparation and characterization of ZrB2-TiB2 based composites for hypersonic systems" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia (2021):83-83,
https://hdl.handle.net/21.15107/rcub_dais_12352 .

Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software

Obradović, Nina; Peleš, Adriana; Olćan, Dragan; Fahrenholtz, William G.; Đorđević, Antonije; Pavlović, Vladimir B.

(Belgrade : Innovation Center of Faculty of Mechanical Engineering, 2021)

TY  - CONF
AU  - Obradović, Nina
AU  - Peleš, Adriana
AU  - Olćan, Dragan
AU  - Fahrenholtz, William G.
AU  - Đorđević, Antonije
AU  - Pavlović, Vladimir B.
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12351
AB  - Our research group has developed a method for measurement of complex relative permittivity of various dielectric materials in the frequency range from around 1 kHz up to several GHz. Material samples have preferably a disk shape. The thicknesses of the samples can be in a wide range, from about 10 μm (thick films) up to several mm. We have designed and manufactured a set of coaxial chambers, which we use as test fixtures. We have also developed two numerical-simulation programs for the electromagnetic analysis of bodies with rotational symmetry. One program is suitable for the low-frequency analysis. It is based on an electrostatic approach. The other program is based on an electrodynamic approach and it is tailored for microwave frequencies. In measurements, we use impedance meters and network analyzers to obtain the input impedance of a chamber with a sample. Thereafter, we implement our software for the electromagnetic modeling to extract the relative permittivity of the measured sample. As examples of verification of our method, we present here results for the relative permittivities of two sets of samples whose sizes are on the extreme limits of the method. The first set comprises poly (vinylidene fluoride) and mechanically activated ZnO nanoparticle composite films, whose relative permittivities are around 1.8. The second set comprises large, high-density samples of spinel (aluminum magnesium oxide) ceramics, sintered under various conditions. The measured relative permittivities of these samples are around 7.5. In all cases, good agreement with other available data has been obtained.
PB  - Belgrade : Innovation Center of Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia
T1  - Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software
SP  - 82
EP  - 82
UR  - https://hdl.handle.net/21.15107/rcub_dais_12351
ER  - 
@conference{
author = "Obradović, Nina and Peleš, Adriana and Olćan, Dragan and Fahrenholtz, William G. and Đorđević, Antonije and Pavlović, Vladimir B.",
year = "2021",
abstract = "Our research group has developed a method for measurement of complex relative permittivity of various dielectric materials in the frequency range from around 1 kHz up to several GHz. Material samples have preferably a disk shape. The thicknesses of the samples can be in a wide range, from about 10 μm (thick films) up to several mm. We have designed and manufactured a set of coaxial chambers, which we use as test fixtures. We have also developed two numerical-simulation programs for the electromagnetic analysis of bodies with rotational symmetry. One program is suitable for the low-frequency analysis. It is based on an electrostatic approach. The other program is based on an electrodynamic approach and it is tailored for microwave frequencies. In measurements, we use impedance meters and network analyzers to obtain the input impedance of a chamber with a sample. Thereafter, we implement our software for the electromagnetic modeling to extract the relative permittivity of the measured sample. As examples of verification of our method, we present here results for the relative permittivities of two sets of samples whose sizes are on the extreme limits of the method. The first set comprises poly (vinylidene fluoride) and mechanically activated ZnO nanoparticle composite films, whose relative permittivities are around 1.8. The second set comprises large, high-density samples of spinel (aluminum magnesium oxide) ceramics, sintered under various conditions. The measured relative permittivities of these samples are around 7.5. In all cases, good agreement with other available data has been obtained.",
publisher = "Belgrade : Innovation Center of Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021, Zlatibor, Serbia",
title = "Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software",
pages = "82-82",
url = "https://hdl.handle.net/21.15107/rcub_dais_12351"
}
Obradović, N., Peleš, A., Olćan, D., Fahrenholtz, W. G., Đorđević, A.,& Pavlović, V. B.. (2021). Measurement of dielectric permitivity using coaxial chambers and electromagnetic-modeling software. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2021,29 June - 02 July 2021,