TY  - JOUR
AU  - Radovanović, Željko
AU  - Veljović, Đorđe
AU  - Radovanović, Lidija
AU  - Zalite, Ilmars
AU  - Palcevskis, Eriks
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3790
AB  - Green hydroxyapatite ceramics were obtained by cold uniaxial and isostatic pressing of hydrothermally synthesized powders, pure hydroxyapatite and hydroxyapatite doped with Ag+, Cu2+ and Zn2+ ions. The ceramics were conventionally and microwave sintered and analyzed by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction analysis, and energy-dispersive X-ray spectroscopy. The effect of doping on the mechanical properties of the obtained hydroxyapatite/tricakium phosphate ceramics was examined by comparing their average grain size, porosity and values of the hardness and fracture toughness. The results showed that doping with Cu(2+ )ions caused the lowest porosity of the ceramics and the highest values of hardness and fracture toughness. The ceramics obtained from hydroxyapatite doped with Ag( )(+)and Zn2+ ions exhibited worse mechanical properties due to the higher porosity even in the case of microwave sintering, which provide denser ceramics than conventional sintering.
PB  - University of Novi Sad, Faculty of Technology
T2  - Processing and Application of Ceramics
T1  - Ag+, Cu2+ and Zn2+ doped hydroxyapatite/tricalcium phosphate bioceramics: Influence of doping and sintering technique on mechanical properties
EP  - 276
IS  - 3
SP  - 268
VL  - 12
DO  - 10.2298/PAC1803268R
ER  - 

@article{
author = "Radovanović, Željko and Veljović, Đorđe and Radovanović, Lidija and Zalite, Ilmars and Palcevskis, Eriks and Petrović, Rada and Janaćković, Đorđe",
year = "2018",
abstract = "Green hydroxyapatite ceramics were obtained by cold uniaxial and isostatic pressing of hydrothermally synthesized powders, pure hydroxyapatite and hydroxyapatite doped with Ag+, Cu2+ and Zn2+ ions. The ceramics were conventionally and microwave sintered and analyzed by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction analysis, and energy-dispersive X-ray spectroscopy. The effect of doping on the mechanical properties of the obtained hydroxyapatite/tricakium phosphate ceramics was examined by comparing their average grain size, porosity and values of the hardness and fracture toughness. The results showed that doping with Cu(2+ )ions caused the lowest porosity of the ceramics and the highest values of hardness and fracture toughness. The ceramics obtained from hydroxyapatite doped with Ag( )(+)and Zn2+ ions exhibited worse mechanical properties due to the higher porosity even in the case of microwave sintering, which provide denser ceramics than conventional sintering.",
publisher = "University of Novi Sad, Faculty of Technology",
journal = "Processing and Application of Ceramics",
title = "Ag+, Cu2+ and Zn2+ doped hydroxyapatite/tricalcium phosphate bioceramics: Influence of doping and sintering technique on mechanical properties",
pages = "276-268",
number = "3",
volume = "12",
doi = "10.2298/PAC1803268R"
}

Radovanović, Ž., Veljović, Đ., Radovanović, L., Zalite, I., Palcevskis, E., Petrović, R.,& Janaćković, Đ.. (2018). Ag+, Cu2+ and Zn2+ doped hydroxyapatite/tricalcium phosphate bioceramics: Influence of doping and sintering technique on mechanical properties. in Processing and Application of Ceramics
University of Novi Sad, Faculty of Technology., 12(3), 268-276.
https://doi.org/10.2298/PAC1803268R

Radovanović Ž, Veljović Đ, Radovanović L, Zalite I, Palcevskis E, Petrović R, Janaćković Đ. Ag+, Cu2+ and Zn2+ doped hydroxyapatite/tricalcium phosphate bioceramics: Influence of doping and sintering technique on mechanical properties. in Processing and Application of Ceramics. 2018;12(3):268-276.
doi:10.2298/PAC1803268R .

Radovanović, Željko, Veljović, Đorđe, Radovanović, Lidija, Zalite, Ilmars, Palcevskis, Eriks, Petrović, Rada, Janaćković, Đorđe, "Ag+, Cu2+ and Zn2+ doped hydroxyapatite/tricalcium phosphate bioceramics: Influence of doping and sintering technique on mechanical properties" in Processing and Application of Ceramics, 12, no. 3 (2018):268-276,
https://doi.org/10.2298/PAC1803268R . .

TY  - JOUR
AU  - Ayoub, Giuma
AU  - Veljović, Đorđe
AU  - Ležaja-Zebić, Maja
AU  - Miletić, Vesna
AU  - Palcevskis, Eriks
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3936
AB  - The objective of the study was to process nano-structured hydroxyapatite/yttrium-stabilized zirconia bioceramic and to investigate the possibilities of its application as dentin replacement in the form of dental inserts. The processing conditions were varied in order to optimize phase composition, microstructure, fracture toughness, hardness and shear bond strength (SBS) between the obtained composite inserts and restorative materials, following either the "total-etch" or "self-etch" clinical protocol. Composite nano-powder, obtained by mixing and homogenization of 80 wt% of stoichiometric hydroxyapatite (HAp) synthesized by modified precipitation method and 20wt% of yttrium-stabilized ZrO2 (YSZ) synthesized by plasma method, was isostatically pressed into cylinder-shaped green bodies. After dilatometric analysis, HAp/YSZ inserts were sintered in the temperature range from 1200 degrees C to 1300 degrees C. Hardness and fracture toughness of sintered inserts were ranged between 3.90 +/- 0.20 - 3.95 +/- 0.12 GPa and 1.82 +/- 0.04 - 1.88 +/- 0.03 MPam(1/2), respectively. Microstructural analysis of biphasic HAp/t-ZrO2 inserts indicated two potential fracture mechanisms for fracture toughness increasing. Sintering temperature and different clinical protocols affected SBS between processed inserts and commercial dental restorative materials. Maximum SBS values of 10.50 +/- 4.94 MPa (mean standard deviation) were reached in inserts sintered at 1300 degrees C, following the "self-etch" protocol of adhesive application. It could be concluded that resin-based composites could be strongly bonded to HAp/YSZ inserts, preferably with self-etch" adhesive application. In addition, the values of fracture toughness and hardness of the obtained inserts indicated the possibility of their usage as dentin substitutes, which could be a good prerequisite for satisfactory mechanics of restored teeth.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes
EP  - 18208
IS  - 15
SP  - 18200
VL  - 44
DO  - 10.1016/j.ceramint.2018.07.028
ER  - 

@article{
author = "Ayoub, Giuma and Veljović, Đorđe and Ležaja-Zebić, Maja and Miletić, Vesna and Palcevskis, Eriks and Petrović, Rada and Janaćković, Đorđe",
year = "2018",
abstract = "The objective of the study was to process nano-structured hydroxyapatite/yttrium-stabilized zirconia bioceramic and to investigate the possibilities of its application as dentin replacement in the form of dental inserts. The processing conditions were varied in order to optimize phase composition, microstructure, fracture toughness, hardness and shear bond strength (SBS) between the obtained composite inserts and restorative materials, following either the "total-etch" or "self-etch" clinical protocol. Composite nano-powder, obtained by mixing and homogenization of 80 wt% of stoichiometric hydroxyapatite (HAp) synthesized by modified precipitation method and 20wt% of yttrium-stabilized ZrO2 (YSZ) synthesized by plasma method, was isostatically pressed into cylinder-shaped green bodies. After dilatometric analysis, HAp/YSZ inserts were sintered in the temperature range from 1200 degrees C to 1300 degrees C. Hardness and fracture toughness of sintered inserts were ranged between 3.90 +/- 0.20 - 3.95 +/- 0.12 GPa and 1.82 +/- 0.04 - 1.88 +/- 0.03 MPam(1/2), respectively. Microstructural analysis of biphasic HAp/t-ZrO2 inserts indicated two potential fracture mechanisms for fracture toughness increasing. Sintering temperature and different clinical protocols affected SBS between processed inserts and commercial dental restorative materials. Maximum SBS values of 10.50 +/- 4.94 MPa (mean standard deviation) were reached in inserts sintered at 1300 degrees C, following the "self-etch" protocol of adhesive application. It could be concluded that resin-based composites could be strongly bonded to HAp/YSZ inserts, preferably with self-etch" adhesive application. In addition, the values of fracture toughness and hardness of the obtained inserts indicated the possibility of their usage as dentin substitutes, which could be a good prerequisite for satisfactory mechanics of restored teeth.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes",
pages = "18208-18200",
number = "15",
volume = "44",
doi = "10.1016/j.ceramint.2018.07.028"
}

Ayoub, G., Veljović, Đ., Ležaja-Zebić, M., Miletić, V., Palcevskis, E., Petrović, R.,& Janaćković, Đ.. (2018). Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes. in Ceramics International
Elsevier Sci Ltd, Oxford., 44(15), 18200-18208.
https://doi.org/10.1016/j.ceramint.2018.07.028

Ayoub G, Veljović Đ, Ležaja-Zebić M, Miletić V, Palcevskis E, Petrović R, Janaćković Đ. Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes. in Ceramics International. 2018;44(15):18200-18208.
doi:10.1016/j.ceramint.2018.07.028 .

Ayoub, Giuma, Veljović, Đorđe, Ležaja-Zebić, Maja, Miletić, Vesna, Palcevskis, Eriks, Petrović, Rada, Janaćković, Đorđe, "Composite nanostructured hydroxyapatite/yttrium stabilized zirconia dental inserts - The processing and application as dentin substitutes" in Ceramics International, 44, no. 15 (2018):18200-18208,
https://doi.org/10.1016/j.ceramint.2018.07.028 . .

TY  - JOUR
AU  - Veljović, Đorđe
AU  - Radovanović, Željko
AU  - Dindune, Antonija
AU  - Palcevskis, Eriks
AU  - Krumina, Aija
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2682
AB  - The aims of this study were to investigate the effects of Sr- and Mn-doped ions on the sintering behaviors, microstructure and mechanical properties of the bioceramics processed by single- and two-step microwave sintering (MWSSS and MWTSS). Nano-sized calcium hydroxyapatite powders doped with Sr and Mn ions, obtained by modified precipitation synthesis, were isostatically pressed at 400 MPa and processed by MWSSS and MWTSS at different temperatures. In all cases during the sintering, the doped HAP powders turned into biphasic mixtures of HAP and TCP, but the amount of TCP was certainly lower in the case of MWTSS. It was shown that the doped ions significantly affected: density, microstructure, grain size, porosity, hardness, and fracture toughness of the processed bioceramics. Two-step microwave sintering was successfully applied for the processing of HAP/TCP bioceramics doped with strontium and manganese ions. Both two-step microwave sintered doped bioceramics had similar and high hardness values, but the strontium-substituted bioceramic material certainly had higher fracture toughness (1.54 MPam(1/2)), with an average grain size of 195 nm. Based on the results presented in this paper, it was concluded that the two-step microwave sintered strontium-doped bioceramics could be suitable materials in the bone regenerative field.
PB  - Springer, New York
T2  - Journal of Materials Science
T1  - The influence of Sr and Mn incorporated ions on the properties of microwave single- and two-step sintered biphasic HAP/TCP bioceramics
EP  - 6802
IS  - 19
SP  - 6793
VL  - 49
DO  - 10.1007/s10853-014-8380-3
ER  - 

@article{
author = "Veljović, Đorđe and Radovanović, Željko and Dindune, Antonija and Palcevskis, Eriks and Krumina, Aija and Petrović, Rada and Janaćković, Đorđe",
year = "2014",
abstract = "The aims of this study were to investigate the effects of Sr- and Mn-doped ions on the sintering behaviors, microstructure and mechanical properties of the bioceramics processed by single- and two-step microwave sintering (MWSSS and MWTSS). Nano-sized calcium hydroxyapatite powders doped with Sr and Mn ions, obtained by modified precipitation synthesis, were isostatically pressed at 400 MPa and processed by MWSSS and MWTSS at different temperatures. In all cases during the sintering, the doped HAP powders turned into biphasic mixtures of HAP and TCP, but the amount of TCP was certainly lower in the case of MWTSS. It was shown that the doped ions significantly affected: density, microstructure, grain size, porosity, hardness, and fracture toughness of the processed bioceramics. Two-step microwave sintering was successfully applied for the processing of HAP/TCP bioceramics doped with strontium and manganese ions. Both two-step microwave sintered doped bioceramics had similar and high hardness values, but the strontium-substituted bioceramic material certainly had higher fracture toughness (1.54 MPam(1/2)), with an average grain size of 195 nm. Based on the results presented in this paper, it was concluded that the two-step microwave sintered strontium-doped bioceramics could be suitable materials in the bone regenerative field.",
publisher = "Springer, New York",
journal = "Journal of Materials Science",
title = "The influence of Sr and Mn incorporated ions on the properties of microwave single- and two-step sintered biphasic HAP/TCP bioceramics",
pages = "6802-6793",
number = "19",
volume = "49",
doi = "10.1007/s10853-014-8380-3"
}

Veljović, Đ., Radovanović, Ž., Dindune, A., Palcevskis, E., Krumina, A., Petrović, R.,& Janaćković, Đ.. (2014). The influence of Sr and Mn incorporated ions on the properties of microwave single- and two-step sintered biphasic HAP/TCP bioceramics. in Journal of Materials Science
Springer, New York., 49(19), 6793-6802.
https://doi.org/10.1007/s10853-014-8380-3

Veljović Đ, Radovanović Ž, Dindune A, Palcevskis E, Krumina A, Petrović R, Janaćković Đ. The influence of Sr and Mn incorporated ions on the properties of microwave single- and two-step sintered biphasic HAP/TCP bioceramics. in Journal of Materials Science. 2014;49(19):6793-6802.
doi:10.1007/s10853-014-8380-3 .

Veljović, Đorđe, Radovanović, Željko, Dindune, Antonija, Palcevskis, Eriks, Krumina, Aija, Petrović, Rada, Janaćković, Đorđe, "The influence of Sr and Mn incorporated ions on the properties of microwave single- and two-step sintered biphasic HAP/TCP bioceramics" in Journal of Materials Science, 49, no. 19 (2014):6793-6802,
https://doi.org/10.1007/s10853-014-8380-3 . .

TY  - JOUR
AU  - Eraković, Sanja
AU  - Janković, Ana
AU  - Veljović, Đorđe
AU  - Palcevskis, Eriks
AU  - Mitrić, Miodrag
AU  - Stevanović, Tatjana
AU  - Janaćković, Đorđe
AU  - Mišković-Stanković, Vesna
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2509
AB  - Hydroxyapatite is the most suitable biocompatible material for bone implant coatings. However, its brittleness is a major obstacle, and that is why, recently, research focused on creating composites with various biopolymers. In this study, hydroxyapatite coatings were modified with lignin in order to attain corrosion stability and surface porosity that enables osteogenesis. Incorporating silver, well known for its antimicrobial properties, seemed the best strategy for avoiding possible infections. The silver/hydroxyapatite (Ag/HAP) and silver/hydroxyapatite/lignin (Ag/HAP/Lig) coatings were cathaphoretically deposited on titanium from ethanol suspensions, sintered at 900 degrees C in Ar, and characterized by X-ray diffraction, scanning electron microscopy, field emission scanning electron microscopy, attenuated total reflection Fourier transform infrared, and X-ray photoelectron spectroscopy. The corrosion stability of electrodeposited coatings was evaluated in vitro in Kokubo's simulated body fluid (SBF) at 37 degrees C using electrochemical impedance spectroscopy. Bioactivity was estimated by immersion in SBF to evaluate the formation of hydroxyapatite on the coating surface. A microcrystalline structure of newly formed plate-shaped carbonate-hydroxyapatite was detected after only 7 days, indicating enhanced bioactive behavior. Both coatings had good corrosion stability during a prolonged immersion time. Among the two, the Ag/HAP/Lig coating had a homogeneous surface, less roughness, and low values of contact angle.
PB  - Amer Chemical Soc, Washington
T2  - Journal of Physical Chemistry B
T1  - Corrosion Stability and Bioactivity in Simulated Body Fluid of Silver/Hydroxyapatite and Silver/Hydroxyapatite/Lignin Coatings on Titanium Obtained by Electrophoretic Deposition
EP  - 1643
IS  - 6
SP  - 1633
VL  - 117
DO  - 10.1021/jp305252a
ER  - 

@article{
author = "Eraković, Sanja and Janković, Ana and Veljović, Đorđe and Palcevskis, Eriks and Mitrić, Miodrag and Stevanović, Tatjana and Janaćković, Đorđe and Mišković-Stanković, Vesna",
year = "2013",
abstract = "Hydroxyapatite is the most suitable biocompatible material for bone implant coatings. However, its brittleness is a major obstacle, and that is why, recently, research focused on creating composites with various biopolymers. In this study, hydroxyapatite coatings were modified with lignin in order to attain corrosion stability and surface porosity that enables osteogenesis. Incorporating silver, well known for its antimicrobial properties, seemed the best strategy for avoiding possible infections. The silver/hydroxyapatite (Ag/HAP) and silver/hydroxyapatite/lignin (Ag/HAP/Lig) coatings were cathaphoretically deposited on titanium from ethanol suspensions, sintered at 900 degrees C in Ar, and characterized by X-ray diffraction, scanning electron microscopy, field emission scanning electron microscopy, attenuated total reflection Fourier transform infrared, and X-ray photoelectron spectroscopy. The corrosion stability of electrodeposited coatings was evaluated in vitro in Kokubo's simulated body fluid (SBF) at 37 degrees C using electrochemical impedance spectroscopy. Bioactivity was estimated by immersion in SBF to evaluate the formation of hydroxyapatite on the coating surface. A microcrystalline structure of newly formed plate-shaped carbonate-hydroxyapatite was detected after only 7 days, indicating enhanced bioactive behavior. Both coatings had good corrosion stability during a prolonged immersion time. Among the two, the Ag/HAP/Lig coating had a homogeneous surface, less roughness, and low values of contact angle.",
publisher = "Amer Chemical Soc, Washington",
journal = "Journal of Physical Chemistry B",
title = "Corrosion Stability and Bioactivity in Simulated Body Fluid of Silver/Hydroxyapatite and Silver/Hydroxyapatite/Lignin Coatings on Titanium Obtained by Electrophoretic Deposition",
pages = "1643-1633",
number = "6",
volume = "117",
doi = "10.1021/jp305252a"
}

Eraković, S., Janković, A., Veljović, Đ., Palcevskis, E., Mitrić, M., Stevanović, T., Janaćković, Đ.,& Mišković-Stanković, V.. (2013). Corrosion Stability and Bioactivity in Simulated Body Fluid of Silver/Hydroxyapatite and Silver/Hydroxyapatite/Lignin Coatings on Titanium Obtained by Electrophoretic Deposition. in Journal of Physical Chemistry B
Amer Chemical Soc, Washington., 117(6), 1633-1643.
https://doi.org/10.1021/jp305252a

Eraković S, Janković A, Veljović Đ, Palcevskis E, Mitrić M, Stevanović T, Janaćković Đ, Mišković-Stanković V. Corrosion Stability and Bioactivity in Simulated Body Fluid of Silver/Hydroxyapatite and Silver/Hydroxyapatite/Lignin Coatings on Titanium Obtained by Electrophoretic Deposition. in Journal of Physical Chemistry B. 2013;117(6):1633-1643.
doi:10.1021/jp305252a .

Eraković, Sanja, Janković, Ana, Veljović, Đorđe, Palcevskis, Eriks, Mitrić, Miodrag, Stevanović, Tatjana, Janaćković, Đorđe, Mišković-Stanković, Vesna, "Corrosion Stability and Bioactivity in Simulated Body Fluid of Silver/Hydroxyapatite and Silver/Hydroxyapatite/Lignin Coatings on Titanium Obtained by Electrophoretic Deposition" in Journal of Physical Chemistry B, 117, no. 6 (2013):1633-1643,
https://doi.org/10.1021/jp305252a . .

TY  - JOUR
AU  - Veljović, Đorđe
AU  - Vuković, Goran D.
AU  - Steins, Ints
AU  - Palcevskis, Eriks
AU  - Uskoković, Petar
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2299
AB  - Composites based on HAP and oxidized multi-walled carbon nanotubes (o-MWCNT) and monophase HAP materials were processed by spark plasma sintering. Starting from stoichiometric nano-sized HAP powder, monophase bioceramics were obtained with a density close to the theoretical one and with an average grain size of several hundred nanometers to micron dimensions. It was shown that decreasing the sintering temperature resulted in a decrease of the grain size, which affected an increase in the fracture toughness and hardness. The fracture toughness of an HAP/ o-MWCNT bioceramic processed at 900°C for only 5 min was 30 % higher than that of monophase HAP materials obtained under the same conditions. The addition of MWCNT during SPS processing of HAP materials caused a decrease in the grain size to the nano-dimension, which was one of the reasons for the improved mechanical properties.
AB  - Kompoziti na bazi hidroksiapatita i oksidovanih višeslojnih karbonskih nanotuba i monofazni hidroksiapatitni materijali dobijeni su spark plazma sinterovanjem. Polazeći od stehiometrijskog nanočestičnog praha hidroksiapatita, dobijeni su monofazni hidroksiapatitni biokeramički materijali sa gustinama bliskim teorijskim vrednostima i prosečnom veličinom zrna od nekoliko stotina nanometara do mikronskih dimenzija. Pokazano je da se sa smanjenjem temperature sinterovanja smanjuje prosečna veličina zrna, što utiče na povećanje žilavosti i tvrdoće materijala. Žilavost kompozitnog biokeramičkog materijala dobijenog na 900°C za svega 5 minuta bila je 30 % veća od žilavosti monofazne hidroksiapatitne biokeramike dobijene pri identičnim parametrima procesiranja. Dodatak oksidovanih karbonskih nanotuba tokom procesiranja spark plazma sinterovanjem, prouzrokovao je smanjenje veličine zrna na nono dimenzije, što je jedan od razloga za poboljšanje mehaničkih svojstava dobijenih materijala.
PB  - International Institute for the Science of Sintering, Beograd
T2  - Science of Sintering
T1  - Improvement of the mechanical properties of spark plasma sintered hap bioceramics by decreasing the grain size and by adding multi-walled carbon nanotubes
EP  - 243
IS  - 2
SP  - 233
VL  - 45
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2299
ER  - 

@article{
author = "Veljović, Đorđe and Vuković, Goran D. and Steins, Ints and Palcevskis, Eriks and Uskoković, Petar and Petrović, Rada and Janaćković, Đorđe",
year = "2013",
abstract = "Composites based on HAP and oxidized multi-walled carbon nanotubes (o-MWCNT) and monophase HAP materials were processed by spark plasma sintering. Starting from stoichiometric nano-sized HAP powder, monophase bioceramics were obtained with a density close to the theoretical one and with an average grain size of several hundred nanometers to micron dimensions. It was shown that decreasing the sintering temperature resulted in a decrease of the grain size, which affected an increase in the fracture toughness and hardness. The fracture toughness of an HAP/ o-MWCNT bioceramic processed at 900°C for only 5 min was 30 % higher than that of monophase HAP materials obtained under the same conditions. The addition of MWCNT during SPS processing of HAP materials caused a decrease in the grain size to the nano-dimension, which was one of the reasons for the improved mechanical properties., Kompoziti na bazi hidroksiapatita i oksidovanih višeslojnih karbonskih nanotuba i monofazni hidroksiapatitni materijali dobijeni su spark plazma sinterovanjem. Polazeći od stehiometrijskog nanočestičnog praha hidroksiapatita, dobijeni su monofazni hidroksiapatitni biokeramički materijali sa gustinama bliskim teorijskim vrednostima i prosečnom veličinom zrna od nekoliko stotina nanometara do mikronskih dimenzija. Pokazano je da se sa smanjenjem temperature sinterovanja smanjuje prosečna veličina zrna, što utiče na povećanje žilavosti i tvrdoće materijala. Žilavost kompozitnog biokeramičkog materijala dobijenog na 900°C za svega 5 minuta bila je 30 % veća od žilavosti monofazne hidroksiapatitne biokeramike dobijene pri identičnim parametrima procesiranja. Dodatak oksidovanih karbonskih nanotuba tokom procesiranja spark plazma sinterovanjem, prouzrokovao je smanjenje veličine zrna na nono dimenzije, što je jedan od razloga za poboljšanje mehaničkih svojstava dobijenih materijala.",
publisher = "International Institute for the Science of Sintering, Beograd",
journal = "Science of Sintering",
title = "Improvement of the mechanical properties of spark plasma sintered hap bioceramics by decreasing the grain size and by adding multi-walled carbon nanotubes",
pages = "243-233",
number = "2",
volume = "45",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2299"
}

Veljović, Đ., Vuković, G. D., Steins, I., Palcevskis, E., Uskoković, P., Petrović, R.,& Janaćković, Đ.. (2013). Improvement of the mechanical properties of spark plasma sintered hap bioceramics by decreasing the grain size and by adding multi-walled carbon nanotubes. in Science of Sintering
International Institute for the Science of Sintering, Beograd., 45(2), 233-243.
https://hdl.handle.net/21.15107/rcub_technorep_2299

Veljović Đ, Vuković GD, Steins I, Palcevskis E, Uskoković P, Petrović R, Janaćković Đ. Improvement of the mechanical properties of spark plasma sintered hap bioceramics by decreasing the grain size and by adding multi-walled carbon nanotubes. in Science of Sintering. 2013;45(2):233-243.
https://hdl.handle.net/21.15107/rcub_technorep_2299 .

Veljović, Đorđe, Vuković, Goran D., Steins, Ints, Palcevskis, Eriks, Uskoković, Petar, Petrović, Rada, Janaćković, Đorđe, "Improvement of the mechanical properties of spark plasma sintered hap bioceramics by decreasing the grain size and by adding multi-walled carbon nanotubes" in Science of Sintering, 45, no. 2 (2013):233-243,
https://hdl.handle.net/21.15107/rcub_technorep_2299 .

TY  - JOUR
AU  - Veljović, Đorđe
AU  - Palcevskis, Eriks
AU  - Zalite, Ilmars
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2537
AB  - Two-step microwave sintering was applied in this study to process dense nano-structured bioceramics coupled with improved mechanical properties. The decrease in the average grain size to the nanolevel resulting from decreasing the sintering temperature to 850 degrees C during two-step microwave sintering, led to an increase in the fracture toughness compared to conventionally two-step sintered bioceramic. The two-step microwave sintering could be a promising technique for the processing of nanostructured HAP bioceramics.
PB  - Elsevier Science Bv, Amsterdam
T2  - Materials Letters
T1  - Two-step microwave sintering-A promising technique for the processing of nanostructured bioceramics
EP  - 253
SP  - 251
VL  - 93
DO  - 10.1016/j.matlet.2012.11.095
ER  - 

@article{
author = "Veljović, Đorđe and Palcevskis, Eriks and Zalite, Ilmars and Petrović, Rada and Janaćković, Đorđe",
year = "2013",
abstract = "Two-step microwave sintering was applied in this study to process dense nano-structured bioceramics coupled with improved mechanical properties. The decrease in the average grain size to the nanolevel resulting from decreasing the sintering temperature to 850 degrees C during two-step microwave sintering, led to an increase in the fracture toughness compared to conventionally two-step sintered bioceramic. The two-step microwave sintering could be a promising technique for the processing of nanostructured HAP bioceramics.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Materials Letters",
title = "Two-step microwave sintering-A promising technique for the processing of nanostructured bioceramics",
pages = "253-251",
volume = "93",
doi = "10.1016/j.matlet.2012.11.095"
}

Veljović, Đ., Palcevskis, E., Zalite, I., Petrović, R.,& Janaćković, Đ.. (2013). Two-step microwave sintering-A promising technique for the processing of nanostructured bioceramics. in Materials Letters
Elsevier Science Bv, Amsterdam., 93, 251-253.
https://doi.org/10.1016/j.matlet.2012.11.095

Veljović Đ, Palcevskis E, Zalite I, Petrović R, Janaćković Đ. Two-step microwave sintering-A promising technique for the processing of nanostructured bioceramics. in Materials Letters. 2013;93:251-253.
doi:10.1016/j.matlet.2012.11.095 .

Veljović, Đorđe, Palcevskis, Eriks, Zalite, Ilmars, Petrović, Rada, Janaćković, Đorđe, "Two-step microwave sintering-A promising technique for the processing of nanostructured bioceramics" in Materials Letters, 93 (2013):251-253,
https://doi.org/10.1016/j.matlet.2012.11.095 . .

TY  - JOUR
AU  - Veljović, Đorđe
AU  - Čolić, Miodrag
AU  - Kojić, Vesna
AU  - Bogdanović, Gordana
AU  - Kojić, Zvezdana
AU  - Banjac, Andrijana
AU  - Palcevskis, Eriks
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2174
AB  - The effect of decreasing the grain size on the biocompatibility, cellmaterial interface, and mechanical properties of microwave-sintered monophase hydroxyapatite bioceramics was investigated in this study. A nanosized stoichiometric hydroxyapatite powder was isostatically pressed at high pressure and sintered in a microwave furnace in order to obtain fine grained dense bioceramics. The samples sintered at 1200 degrees C, with a density near the theoretical one, were composed of micron-sized grains, while the grain size decreased to 130 nm on decreasing the sintering temperature to 900 degrees C. This decrease in the grain size certainly led to increases in the fracture toughness by much as 54%. An in vitro investigation of biocompatibility with L929 and human MRC-5 fibroblast cells showed noncytotoxic effects for both types of bioceramics, while the relative cell proliferation rate, cell attachment and metabolic activity of the fibroblasts were improved with decreasing of grain size. An initial in vivo investigation of biocompatibility by the primary cutaneous irritation test showed that both materials exhibited no irritation properties.
PB  - Wiley, Hoboken
T2  - Journal of Biomedical Materials Research Part A
T1  - The effect of grain size on the biocompatibility, cell-materials interface, and mechanical properties of microwave-sintered bioceramics
EP  - 3070
IS  - 11
SP  - 3059
VL  - 100A
DO  - 10.1002/jbm.a.34225
ER  - 

@article{
author = "Veljović, Đorđe and Čolić, Miodrag and Kojić, Vesna and Bogdanović, Gordana and Kojić, Zvezdana and Banjac, Andrijana and Palcevskis, Eriks and Petrović, Rada and Janaćković, Đorđe",
year = "2012",
abstract = "The effect of decreasing the grain size on the biocompatibility, cellmaterial interface, and mechanical properties of microwave-sintered monophase hydroxyapatite bioceramics was investigated in this study. A nanosized stoichiometric hydroxyapatite powder was isostatically pressed at high pressure and sintered in a microwave furnace in order to obtain fine grained dense bioceramics. The samples sintered at 1200 degrees C, with a density near the theoretical one, were composed of micron-sized grains, while the grain size decreased to 130 nm on decreasing the sintering temperature to 900 degrees C. This decrease in the grain size certainly led to increases in the fracture toughness by much as 54%. An in vitro investigation of biocompatibility with L929 and human MRC-5 fibroblast cells showed noncytotoxic effects for both types of bioceramics, while the relative cell proliferation rate, cell attachment and metabolic activity of the fibroblasts were improved with decreasing of grain size. An initial in vivo investigation of biocompatibility by the primary cutaneous irritation test showed that both materials exhibited no irritation properties.",
publisher = "Wiley, Hoboken",
journal = "Journal of Biomedical Materials Research Part A",
title = "The effect of grain size on the biocompatibility, cell-materials interface, and mechanical properties of microwave-sintered bioceramics",
pages = "3070-3059",
number = "11",
volume = "100A",
doi = "10.1002/jbm.a.34225"
}

Veljović, Đ., Čolić, M., Kojić, V., Bogdanović, G., Kojić, Z., Banjac, A., Palcevskis, E., Petrović, R.,& Janaćković, Đ.. (2012). The effect of grain size on the biocompatibility, cell-materials interface, and mechanical properties of microwave-sintered bioceramics. in Journal of Biomedical Materials Research Part A
Wiley, Hoboken., 100A(11), 3059-3070.
https://doi.org/10.1002/jbm.a.34225

Veljović Đ, Čolić M, Kojić V, Bogdanović G, Kojić Z, Banjac A, Palcevskis E, Petrović R, Janaćković Đ. The effect of grain size on the biocompatibility, cell-materials interface, and mechanical properties of microwave-sintered bioceramics. in Journal of Biomedical Materials Research Part A. 2012;100A(11):3059-3070.
doi:10.1002/jbm.a.34225 .

Veljović, Đorđe, Čolić, Miodrag, Kojić, Vesna, Bogdanović, Gordana, Kojić, Zvezdana, Banjac, Andrijana, Palcevskis, Eriks, Petrović, Rada, Janaćković, Đorđe, "The effect of grain size on the biocompatibility, cell-materials interface, and mechanical properties of microwave-sintered bioceramics" in Journal of Biomedical Materials Research Part A, 100A, no. 11 (2012):3059-3070,
https://doi.org/10.1002/jbm.a.34225 . .

TY  - JOUR
AU  - Palcevskis, Eriks
AU  - Dindune, Antonija
AU  - Dekhtyar, Y.
AU  - Polyaka, N.
AU  - Veljović, Đorđe
AU  - Sammons, R. L.
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1882
AB  - The influence of hydrogenation on the biocompatibility of different hydroxyapatite (HAP) materials was tested. Materials consisted of pure HAP, HAP substituted with manganese (Mn+2) and with magnesium (Mg+2) - all axially pressed and conventionally sintered for 2 h at 1200 degrees C; pure HAP isostatic pressed and sintered by a microwave technique for 15 min at temperature of 1200 degrees C. Biocompatibility was compared by enumeration of the number of osteoblast-like cells to the materials before and after hydrogenation. Obtained results show that the osteoblastic cells demonstrated a higher ability to attach to HAP if its surface was negatively charged. Hydrogenation altered the surface potential; HAP substituted with manganese - HAP(Mn) and with magnesium - HAP(Mg) demonstrated the highest ability to engineer the charge.
PB  - IOP Publishing Ltd, Bristol
T2  - Annual Conference on Functional Materials and Nanotechnologies - FM&NT 2011
T1  - The Influence of Surface Treatment by Hydrogenation on the Biocompatibility of Different Hydroxyapatite Materials
VL  - 23
DO  - 10.1088/1757-899X/23/1/012032
ER  - 

@article{
author = "Palcevskis, Eriks and Dindune, Antonija and Dekhtyar, Y. and Polyaka, N. and Veljović, Đorđe and Sammons, R. L.",
year = "2011",
abstract = "The influence of hydrogenation on the biocompatibility of different hydroxyapatite (HAP) materials was tested. Materials consisted of pure HAP, HAP substituted with manganese (Mn+2) and with magnesium (Mg+2) - all axially pressed and conventionally sintered for 2 h at 1200 degrees C; pure HAP isostatic pressed and sintered by a microwave technique for 15 min at temperature of 1200 degrees C. Biocompatibility was compared by enumeration of the number of osteoblast-like cells to the materials before and after hydrogenation. Obtained results show that the osteoblastic cells demonstrated a higher ability to attach to HAP if its surface was negatively charged. Hydrogenation altered the surface potential; HAP substituted with manganese - HAP(Mn) and with magnesium - HAP(Mg) demonstrated the highest ability to engineer the charge.",
publisher = "IOP Publishing Ltd, Bristol",
journal = "Annual Conference on Functional Materials and Nanotechnologies - FM&NT 2011",
title = "The Influence of Surface Treatment by Hydrogenation on the Biocompatibility of Different Hydroxyapatite Materials",
volume = "23",
doi = "10.1088/1757-899X/23/1/012032"
}

Palcevskis, E., Dindune, A., Dekhtyar, Y., Polyaka, N., Veljović, Đ.,& Sammons, R. L.. (2011). The Influence of Surface Treatment by Hydrogenation on the Biocompatibility of Different Hydroxyapatite Materials. in Annual Conference on Functional Materials and Nanotechnologies - FM&NT 2011
IOP Publishing Ltd, Bristol., 23.
https://doi.org/10.1088/1757-899X/23/1/012032

Palcevskis E, Dindune A, Dekhtyar Y, Polyaka N, Veljović Đ, Sammons RL. The Influence of Surface Treatment by Hydrogenation on the Biocompatibility of Different Hydroxyapatite Materials. in Annual Conference on Functional Materials and Nanotechnologies - FM&NT 2011. 2011;23.
doi:10.1088/1757-899X/23/1/012032 .

Palcevskis, Eriks, Dindune, Antonija, Dekhtyar, Y., Polyaka, N., Veljović, Đorđe, Sammons, R. L., "The Influence of Surface Treatment by Hydrogenation on the Biocompatibility of Different Hydroxyapatite Materials" in Annual Conference on Functional Materials and Nanotechnologies - FM&NT 2011, 23 (2011),
https://doi.org/10.1088/1757-899X/23/1/012032 . .

TY  - CONF
AU  - Palcevskis, Eriks
AU  - Dekhtyar, Y.
AU  - Dindune, Antonija
AU  - Kanepe, Z.
AU  - Krastins, J.
AU  - Polyaka, N.
AU  - Veljović, Đorđe
AU  - Sammons, R.
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1742
PB  - 24th European Conference on Biomaterials, EBS 2011
C3  - 24th European Conference on Biomaterials - Annual Conference of the European Society for Biomaterial
T1  - Hydrogenated hydroxyapatite materials with improved biocompatibility
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1742
ER  - 

@conference{
author = "Palcevskis, Eriks and Dekhtyar, Y. and Dindune, Antonija and Kanepe, Z. and Krastins, J. and Polyaka, N. and Veljović, Đorđe and Sammons, R.",
year = "2011",
publisher = "24th European Conference on Biomaterials, EBS 2011",
journal = "24th European Conference on Biomaterials - Annual Conference of the European Society for Biomaterial",
title = "Hydrogenated hydroxyapatite materials with improved biocompatibility",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1742"
}

Palcevskis, E., Dekhtyar, Y., Dindune, A., Kanepe, Z., Krastins, J., Polyaka, N., Veljović, Đ.,& Sammons, R.. (2011). Hydrogenated hydroxyapatite materials with improved biocompatibility. in 24th European Conference on Biomaterials - Annual Conference of the European Society for Biomaterial
24th European Conference on Biomaterials, EBS 2011..
https://hdl.handle.net/21.15107/rcub_technorep_1742

Palcevskis E, Dekhtyar Y, Dindune A, Kanepe Z, Krastins J, Polyaka N, Veljović Đ, Sammons R. Hydrogenated hydroxyapatite materials with improved biocompatibility. in 24th European Conference on Biomaterials - Annual Conference of the European Society for Biomaterial. 2011;.
https://hdl.handle.net/21.15107/rcub_technorep_1742 .

Palcevskis, Eriks, Dekhtyar, Y., Dindune, Antonija, Kanepe, Z., Krastins, J., Polyaka, N., Veljović, Đorđe, Sammons, R., "Hydrogenated hydroxyapatite materials with improved biocompatibility" in 24th European Conference on Biomaterials - Annual Conference of the European Society for Biomaterial (2011),
https://hdl.handle.net/21.15107/rcub_technorep_1742 .

TY  - JOUR
AU  - Veljović, Đorđe
AU  - Palcevskis, Eriks
AU  - Dindune, Antonija
AU  - Putić, Slaviša
AU  - Balać, Igor
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1703
AB  - Starting from two microspherical agglomerated HAP powders, porous biphasic HAP/TCP bioceramics were obtained by microwave sintering. During the sintering the HAP powders turned into biphasic mixtures, whereby HAP was the dominant crystalline phase in the case of the sample with the higher Ca/P ratio (HAP1) while alpha-TCP was the dominant crystalline phase in the sample with lower Ca/P ratio (HAP2). The porous microstructures of the obtained bioceramics were characterized by spherical intra-agglomerate pores and shapeless inter-agglomerate pores. The fracture toughness of the HAP1 and HAP2 samples microwave sintered at 1200 A degrees C for 15 min were 1.25 MPa m(1/2). The phase composition of the obtained bioceramics only had a minor effect on the indentation fracture toughness compared to a unique microstructure consisting of spherical intra-agglomerate pores with strong bonds between the spherical agglomerates. Cold isostatic pressing at 400 MPa before microwave sintering led to an increase in the fracture toughness of the biphasic HAP/TCP bioceramics to 1.35 MPa m(1/2).
PB  - Springer, New York
T2  - Journal of Materials Science
T1  - Microwave sintering improves the mechanical properties of biphasic calcium phosphates from hydroxyapatite microspheres produced from hydrothermal processing
EP  - 3183
IS  - 12
SP  - 3175
VL  - 45
DO  - 10.1007/s10853-010-4324-8
ER  - 

@article{
author = "Veljović, Đorđe and Palcevskis, Eriks and Dindune, Antonija and Putić, Slaviša and Balać, Igor and Petrović, Rada and Janaćković, Đorđe",
year = "2010",
abstract = "Starting from two microspherical agglomerated HAP powders, porous biphasic HAP/TCP bioceramics were obtained by microwave sintering. During the sintering the HAP powders turned into biphasic mixtures, whereby HAP was the dominant crystalline phase in the case of the sample with the higher Ca/P ratio (HAP1) while alpha-TCP was the dominant crystalline phase in the sample with lower Ca/P ratio (HAP2). The porous microstructures of the obtained bioceramics were characterized by spherical intra-agglomerate pores and shapeless inter-agglomerate pores. The fracture toughness of the HAP1 and HAP2 samples microwave sintered at 1200 A degrees C for 15 min were 1.25 MPa m(1/2). The phase composition of the obtained bioceramics only had a minor effect on the indentation fracture toughness compared to a unique microstructure consisting of spherical intra-agglomerate pores with strong bonds between the spherical agglomerates. Cold isostatic pressing at 400 MPa before microwave sintering led to an increase in the fracture toughness of the biphasic HAP/TCP bioceramics to 1.35 MPa m(1/2).",
publisher = "Springer, New York",
journal = "Journal of Materials Science",
title = "Microwave sintering improves the mechanical properties of biphasic calcium phosphates from hydroxyapatite microspheres produced from hydrothermal processing",
pages = "3183-3175",
number = "12",
volume = "45",
doi = "10.1007/s10853-010-4324-8"
}

Veljović, Đ., Palcevskis, E., Dindune, A., Putić, S., Balać, I., Petrović, R.,& Janaćković, Đ.. (2010). Microwave sintering improves the mechanical properties of biphasic calcium phosphates from hydroxyapatite microspheres produced from hydrothermal processing. in Journal of Materials Science
Springer, New York., 45(12), 3175-3183.
https://doi.org/10.1007/s10853-010-4324-8

Veljović Đ, Palcevskis E, Dindune A, Putić S, Balać I, Petrović R, Janaćković Đ. Microwave sintering improves the mechanical properties of biphasic calcium phosphates from hydroxyapatite microspheres produced from hydrothermal processing. in Journal of Materials Science. 2010;45(12):3175-3183.
doi:10.1007/s10853-010-4324-8 .

Veljović, Đorđe, Palcevskis, Eriks, Dindune, Antonija, Putić, Slaviša, Balać, Igor, Petrović, Rada, Janaćković, Đorđe, "Microwave sintering improves the mechanical properties of biphasic calcium phosphates from hydroxyapatite microspheres produced from hydrothermal processing" in Journal of Materials Science, 45, no. 12 (2010):3175-3183,
https://doi.org/10.1007/s10853-010-4324-8 . .

TY  - JOUR
AU  - Veljović, Đorđe
AU  - Zalite, Ilmars
AU  - Palcevskis, Eriks
AU  - Smičiklas, Ivana D.
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1683
AB  - The effect of microwave sintering conditions on the microstructure, phase composition and mechanical properties of materials based on hydroxyapatite (HAP) and tricalcium phosphate (TCP) was investigated. Fine grained monophase HAP and biphasic HAP/TCP biomaterials were processed starting from stoichiometric and calcium deficient nanosized HAP powders. The HAP samples microwave (MAT) sintered for 15 min at 900 degrees C, with average grain size of 130 nm, showed better densification, higher density and certainly higher hardness and fracture toughness than samples conventionally sintered for 2 h at the same temperature. By comparing MW sintered HAP and HAP/TCP samples, it was concluded that pure HAP ceramics have superior mechanical properties. For monophase MW sintered HAP samples, the decrease in the grain size from 1.59 mu m to 130 nm led to an increase in the fracture toughness from 0.85 MPa m(1/2) to 1.3 MPa m(1/2).
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Microwave sintering of fine grained HAP and HAP/TCP bioceramics
EP  - 603
IS  - 2
SP  - 595
VL  - 36
DO  - 10.1016/j.ceramint.2009.09.038
ER  - 

@article{
author = "Veljović, Đorđe and Zalite, Ilmars and Palcevskis, Eriks and Smičiklas, Ivana D. and Petrović, Rada and Janaćković, Đorđe",
year = "2010",
abstract = "The effect of microwave sintering conditions on the microstructure, phase composition and mechanical properties of materials based on hydroxyapatite (HAP) and tricalcium phosphate (TCP) was investigated. Fine grained monophase HAP and biphasic HAP/TCP biomaterials were processed starting from stoichiometric and calcium deficient nanosized HAP powders. The HAP samples microwave (MAT) sintered for 15 min at 900 degrees C, with average grain size of 130 nm, showed better densification, higher density and certainly higher hardness and fracture toughness than samples conventionally sintered for 2 h at the same temperature. By comparing MW sintered HAP and HAP/TCP samples, it was concluded that pure HAP ceramics have superior mechanical properties. For monophase MW sintered HAP samples, the decrease in the grain size from 1.59 mu m to 130 nm led to an increase in the fracture toughness from 0.85 MPa m(1/2) to 1.3 MPa m(1/2).",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Microwave sintering of fine grained HAP and HAP/TCP bioceramics",
pages = "603-595",
number = "2",
volume = "36",
doi = "10.1016/j.ceramint.2009.09.038"
}

Veljović, Đ., Zalite, I., Palcevskis, E., Smičiklas, I. D., Petrović, R.,& Janaćković, Đ.. (2010). Microwave sintering of fine grained HAP and HAP/TCP bioceramics. in Ceramics International
Elsevier Sci Ltd, Oxford., 36(2), 595-603.
https://doi.org/10.1016/j.ceramint.2009.09.038

Veljović Đ, Zalite I, Palcevskis E, Smičiklas ID, Petrović R, Janaćković Đ. Microwave sintering of fine grained HAP and HAP/TCP bioceramics. in Ceramics International. 2010;36(2):595-603.
doi:10.1016/j.ceramint.2009.09.038 .

Veljović, Đorđe, Zalite, Ilmars, Palcevskis, Eriks, Smičiklas, Ivana D., Petrović, Rada, Janaćković, Đorđe, "Microwave sintering of fine grained HAP and HAP/TCP bioceramics" in Ceramics International, 36, no. 2 (2010):595-603,
https://doi.org/10.1016/j.ceramint.2009.09.038 . .

TY  - JOUR
AU  - Veljović, Đorđe
AU  - Jokić, Bojan
AU  - Petrović, Rada
AU  - Palcevskis, Eriks
AU  - Dindune, Antonija
AU  - Mihailescu, Ion N.
AU  - Janaćković, Đorđe
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1504
AB  - A nanosized HAP powder was sintered and hot pressed, in order to obtain dense HAP ceramics. In a first series of experiments, the powder was isostatically pressed into uniform green compacts and sintered at temperatures ranging from 1000 degrees C to 1200 degrees C in air atmosphere for different times. In a second series, the isostatically pressed green compacts were hot pressed in argon atmosphere at 900 degrees C, 950 degrees C and 1000 degrees C. The SEM micrograph of the sample sintered at 1200 degrees C for 2 h showed a uniform 3 mu m mean grain size dense microstructure. In the case of hot pressed HAP compacts, full dense, translucent nanostructures were obtained having mean grain size below 100 nm and improved mechanical properties. With the grain size decreasing from 3 mu m to 50 nm, the fracture toughness of pure HAP ceramics increased from 0.28 MPa m(1/2) to 1.52 MPa m(1/2).
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Processing of dense nanostructured HAP ceramics by sintering and hot pressing
EP  - 1413
IS  - 4
SP  - 1407
VL  - 35
DO  - 10.1016/j.ceramint.2008.07.007
ER  - 

@article{
author = "Veljović, Đorđe and Jokić, Bojan and Petrović, Rada and Palcevskis, Eriks and Dindune, Antonija and Mihailescu, Ion N. and Janaćković, Đorđe",
year = "2009",
abstract = "A nanosized HAP powder was sintered and hot pressed, in order to obtain dense HAP ceramics. In a first series of experiments, the powder was isostatically pressed into uniform green compacts and sintered at temperatures ranging from 1000 degrees C to 1200 degrees C in air atmosphere for different times. In a second series, the isostatically pressed green compacts were hot pressed in argon atmosphere at 900 degrees C, 950 degrees C and 1000 degrees C. The SEM micrograph of the sample sintered at 1200 degrees C for 2 h showed a uniform 3 mu m mean grain size dense microstructure. In the case of hot pressed HAP compacts, full dense, translucent nanostructures were obtained having mean grain size below 100 nm and improved mechanical properties. With the grain size decreasing from 3 mu m to 50 nm, the fracture toughness of pure HAP ceramics increased from 0.28 MPa m(1/2) to 1.52 MPa m(1/2).",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Processing of dense nanostructured HAP ceramics by sintering and hot pressing",
pages = "1413-1407",
number = "4",
volume = "35",
doi = "10.1016/j.ceramint.2008.07.007"
}

Veljović, Đ., Jokić, B., Petrović, R., Palcevskis, E., Dindune, A., Mihailescu, I. N.,& Janaćković, Đ.. (2009). Processing of dense nanostructured HAP ceramics by sintering and hot pressing. in Ceramics International
Elsevier Sci Ltd, Oxford., 35(4), 1407-1413.
https://doi.org/10.1016/j.ceramint.2008.07.007

Veljović Đ, Jokić B, Petrović R, Palcevskis E, Dindune A, Mihailescu IN, Janaćković Đ. Processing of dense nanostructured HAP ceramics by sintering and hot pressing. in Ceramics International. 2009;35(4):1407-1413.
doi:10.1016/j.ceramint.2008.07.007 .

Veljović, Đorđe, Jokić, Bojan, Petrović, Rada, Palcevskis, Eriks, Dindune, Antonija, Mihailescu, Ion N., Janaćković, Đorđe, "Processing of dense nanostructured HAP ceramics by sintering and hot pressing" in Ceramics International, 35, no. 4 (2009):1407-1413,
https://doi.org/10.1016/j.ceramint.2008.07.007 . .

TY  - JOUR
AU  - Gyorgy, E.
AU  - Grigorescu, S.
AU  - Socol, Gabriel
AU  - Mihailescu, Ion N.
AU  - Janaćković, Đorđe
AU  - Dindune, Antonija
AU  - Kanepe, Z.
AU  - Palcevskis, Eriks
AU  - Zdrentu, E. L.
AU  - Petrescu, S. M.
PY  - 2007
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1170
AB  - Bioactive glass (BG), calcium hydroxyapatite (HA), and ZrO2 doped HA thin films were grown by pulsed laser deposition on Ti substrates. An UV KrF* (lambda = 248 nm, tau  gt = 7 ns) excimer laser was used for the multi-pulse irradiation of the targets. The substrates were kept at room temperature or heated during the film deposition at values within the (400-550 degrees C) range. The depositions were performed in oxygen and water vapor atmospheres, at pressure values in the range (5-40 Pa). The HA coatings were heat post-treated for 6 h in a flux of hot water vapors at the same temperature as applied during deposition. The surface morphology, chemical composition, and crystalline quality of the obtained thin films were studied by scanning electron microscopy, atomic force microscopy, and X-ray diffractometry. The films were seeded for in vitro tests with Hek293 (human embryonic kidney) cells that revealed a good adherence on the deposited layers. Biocompatibility tests showed that cell growth was better on HA than on BG thin films.
PB  - Elsevier, Amsterdam
T2  - Applied Surface Science
T1  - Bioactive glass and hydroxyapatite thin films obtained by pulsed laser deposition
EP  - 7986
IS  - 19
SP  - 7981
VL  - 253
DO  - 10.1016/j.apsusc.2007.02.146
ER  - 

@article{
author = "Gyorgy, E. and Grigorescu, S. and Socol, Gabriel and Mihailescu, Ion N. and Janaćković, Đorđe and Dindune, Antonija and Kanepe, Z. and Palcevskis, Eriks and Zdrentu, E. L. and Petrescu, S. M.",
year = "2007",
abstract = "Bioactive glass (BG), calcium hydroxyapatite (HA), and ZrO2 doped HA thin films were grown by pulsed laser deposition on Ti substrates. An UV KrF* (lambda = 248 nm, tau  gt = 7 ns) excimer laser was used for the multi-pulse irradiation of the targets. The substrates were kept at room temperature or heated during the film deposition at values within the (400-550 degrees C) range. The depositions were performed in oxygen and water vapor atmospheres, at pressure values in the range (5-40 Pa). The HA coatings were heat post-treated for 6 h in a flux of hot water vapors at the same temperature as applied during deposition. The surface morphology, chemical composition, and crystalline quality of the obtained thin films were studied by scanning electron microscopy, atomic force microscopy, and X-ray diffractometry. The films were seeded for in vitro tests with Hek293 (human embryonic kidney) cells that revealed a good adherence on the deposited layers. Biocompatibility tests showed that cell growth was better on HA than on BG thin films.",
publisher = "Elsevier, Amsterdam",
journal = "Applied Surface Science",
title = "Bioactive glass and hydroxyapatite thin films obtained by pulsed laser deposition",
pages = "7986-7981",
number = "19",
volume = "253",
doi = "10.1016/j.apsusc.2007.02.146"
}

Gyorgy, E., Grigorescu, S., Socol, G., Mihailescu, I. N., Janaćković, Đ., Dindune, A., Kanepe, Z., Palcevskis, E., Zdrentu, E. L.,& Petrescu, S. M.. (2007). Bioactive glass and hydroxyapatite thin films obtained by pulsed laser deposition. in Applied Surface Science
Elsevier, Amsterdam., 253(19), 7981-7986.
https://doi.org/10.1016/j.apsusc.2007.02.146

Gyorgy E, Grigorescu S, Socol G, Mihailescu IN, Janaćković Đ, Dindune A, Kanepe Z, Palcevskis E, Zdrentu EL, Petrescu SM. Bioactive glass and hydroxyapatite thin films obtained by pulsed laser deposition. in Applied Surface Science. 2007;253(19):7981-7986.
doi:10.1016/j.apsusc.2007.02.146 .

Gyorgy, E., Grigorescu, S., Socol, Gabriel, Mihailescu, Ion N., Janaćković, Đorđe, Dindune, Antonija, Kanepe, Z., Palcevskis, Eriks, Zdrentu, E. L., Petrescu, S. M., "Bioactive glass and hydroxyapatite thin films obtained by pulsed laser deposition" in Applied Surface Science, 253, no. 19 (2007):7981-7986,
https://doi.org/10.1016/j.apsusc.2007.02.146 . .