TY  - JOUR
AU  - Gligorijević, Bojan R.
AU  - Vilotijević, Miroljub N.
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6638
AB  - The current study focuses on creating an initial highly alkaline simulated body fluid whose pH can be decreased to a physiological range by adding CO2 (protein-free simulated body fluid) or a combination of CO2 and human proteins (protein-containing simulated body fluid). The effects of dissolved human proteins, Ca2+ ions, and immersed plasma-sprayed hydroxyapatite coatings on the pH and chemical instability of prepared simulated body fluids were investigated. The physiological concentration of dissolved human proteins decreased the pH instability in prepared simulated body fluids by 60% and the physiological concentration of dissolved Ca2+ ions by 15%. The effect of immersing the hydroxyapatite coatings was negligible. In terms of chemical instability, the dissolution of Ca2+ ions caused the blurring of protein-free simulated body fluids after 0.6-1.0 h. In protein-containing simulated body fluids, this phenomenon was undetectable due to their opacity. The effects of human protein presence on the carbonated-apatite-forming ability on the surfaces of immersed hydroxyapatite coatings in the prepared simulated body fluids were also assessed. The experiments validated the bioactivity of plasma-sprayed hydroxyapatite coatings in the prepared simulated body fluids, regardless of protein presence. On the other hand, under the different experimental conditions (unregulated or regulated pH), the human protein presence had an inhibitory (unregulated pH) or indifferent/promoting (regulated pH) influence on the carbonated-apatite-forming ability. The results of the present study are discussed, as well as the strengths and shortcomings of the prepared simulated body fluids, and are compared to those of previous relevant investigations.
PB  - Iranian Institute of Research and Development in Chemical Industries
T2  - Iranian Journal of Chemistry and Chemical Engineering
T1  - Simulated Body Fluids Prepared with Natural Buffers and System for Active pH Regulation
EP  - 2935
IS  - 9
SP  - 2918
VL  - 41
DO  - 10.30492/ijcce.2021.530070.4823
ER  - 

@article{
author = "Gligorijević, Bojan R. and Vilotijević, Miroljub N.",
year = "2022",
abstract = "The current study focuses on creating an initial highly alkaline simulated body fluid whose pH can be decreased to a physiological range by adding CO2 (protein-free simulated body fluid) or a combination of CO2 and human proteins (protein-containing simulated body fluid). The effects of dissolved human proteins, Ca2+ ions, and immersed plasma-sprayed hydroxyapatite coatings on the pH and chemical instability of prepared simulated body fluids were investigated. The physiological concentration of dissolved human proteins decreased the pH instability in prepared simulated body fluids by 60% and the physiological concentration of dissolved Ca2+ ions by 15%. The effect of immersing the hydroxyapatite coatings was negligible. In terms of chemical instability, the dissolution of Ca2+ ions caused the blurring of protein-free simulated body fluids after 0.6-1.0 h. In protein-containing simulated body fluids, this phenomenon was undetectable due to their opacity. The effects of human protein presence on the carbonated-apatite-forming ability on the surfaces of immersed hydroxyapatite coatings in the prepared simulated body fluids were also assessed. The experiments validated the bioactivity of plasma-sprayed hydroxyapatite coatings in the prepared simulated body fluids, regardless of protein presence. On the other hand, under the different experimental conditions (unregulated or regulated pH), the human protein presence had an inhibitory (unregulated pH) or indifferent/promoting (regulated pH) influence on the carbonated-apatite-forming ability. The results of the present study are discussed, as well as the strengths and shortcomings of the prepared simulated body fluids, and are compared to those of previous relevant investigations.",
publisher = "Iranian Institute of Research and Development in Chemical Industries",
journal = "Iranian Journal of Chemistry and Chemical Engineering",
title = "Simulated Body Fluids Prepared with Natural Buffers and System for Active pH Regulation",
pages = "2935-2918",
number = "9",
volume = "41",
doi = "10.30492/ijcce.2021.530070.4823"
}

Gligorijević, B. R.,& Vilotijević, M. N.. (2022). Simulated Body Fluids Prepared with Natural Buffers and System for Active pH Regulation. in Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries., 41(9), 2918-2935.
https://doi.org/10.30492/ijcce.2021.530070.4823

Gligorijević BR, Vilotijević MN. Simulated Body Fluids Prepared with Natural Buffers and System for Active pH Regulation. in Iranian Journal of Chemistry and Chemical Engineering. 2022;41(9):2918-2935.
doi:10.30492/ijcce.2021.530070.4823 .

Gligorijević, Bojan R., Vilotijević, Miroljub N., "Simulated Body Fluids Prepared with Natural Buffers and System for Active pH Regulation" in Iranian Journal of Chemistry and Chemical Engineering, 41, no. 9 (2022):2918-2935,
https://doi.org/10.30492/ijcce.2021.530070.4823 . .

TY  - JOUR
AU  - Gligorijević, Bojan
AU  - Vilotijević, Miroljub N.
AU  - Scepanović, Maja
AU  - Radovanović, Radovan V.
AU  - Radović, Nenad
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3562
AB  - The present study estimated the cracking phenomenon in as-plasma-sprayed hydroxylapatite coatings (HACs) after they were being subjected to the severe cutting conditions in the direction perpendicular to the coating/substrate interface. In order to evaluate the effects of substrate preheating on the occurrence of micro-cracks, the HACs were deposited at different initial substrate temperatures (T-S = 20, 100 and 200 degrees C). The changes in phase composition and HA splat morphology with T-S were observed and were correlated with the cracking occurrence. The results showed that severe cutting conditions introduced a localized cracking in the regions of HACs dominantly attributed to the brittle hydroxyl- deficient amorphous calcium phosphate (ACP) phase. This effect was particularly observable in the HACs deposited without preheating of substrate. On the other hand, the preheating of substrate reduced the presence of micro-cracks and caused insignificant changes in the average local phase composition. In HACs deposited with preheating of substrate, the HA splats (of which HACs are composed) were thinner and recrystallized HA regions seemed smaller in size and more evenly distributed. These results implied potentially important roles of the HA splat formation mechanism on the distribution of ACP and recrystallized HA regions in the as-plasma-sprayed HACs and the cracking resistance of HACs.
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Cracking caused by cutting of plasma-sprayed hydroxyapatite coatings and its relation to the structural features of coatings deposited at different initial substrate temperatures
EP  - 249
IS  - 3
SP  - 241
VL  - 71
DO  - 10.2298/HEMIND160513034G
ER  - 

@article{
author = "Gligorijević, Bojan and Vilotijević, Miroljub N. and Scepanović, Maja and Radovanović, Radovan V. and Radović, Nenad",
year = "2017",
abstract = "The present study estimated the cracking phenomenon in as-plasma-sprayed hydroxylapatite coatings (HACs) after they were being subjected to the severe cutting conditions in the direction perpendicular to the coating/substrate interface. In order to evaluate the effects of substrate preheating on the occurrence of micro-cracks, the HACs were deposited at different initial substrate temperatures (T-S = 20, 100 and 200 degrees C). The changes in phase composition and HA splat morphology with T-S were observed and were correlated with the cracking occurrence. The results showed that severe cutting conditions introduced a localized cracking in the regions of HACs dominantly attributed to the brittle hydroxyl- deficient amorphous calcium phosphate (ACP) phase. This effect was particularly observable in the HACs deposited without preheating of substrate. On the other hand, the preheating of substrate reduced the presence of micro-cracks and caused insignificant changes in the average local phase composition. In HACs deposited with preheating of substrate, the HA splats (of which HACs are composed) were thinner and recrystallized HA regions seemed smaller in size and more evenly distributed. These results implied potentially important roles of the HA splat formation mechanism on the distribution of ACP and recrystallized HA regions in the as-plasma-sprayed HACs and the cracking resistance of HACs.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Cracking caused by cutting of plasma-sprayed hydroxyapatite coatings and its relation to the structural features of coatings deposited at different initial substrate temperatures",
pages = "249-241",
number = "3",
volume = "71",
doi = "10.2298/HEMIND160513034G"
}

Gligorijević, B., Vilotijević, M. N., Scepanović, M., Radovanović, R. V.,& Radović, N.. (2017). Cracking caused by cutting of plasma-sprayed hydroxyapatite coatings and its relation to the structural features of coatings deposited at different initial substrate temperatures. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 71(3), 241-249.
https://doi.org/10.2298/HEMIND160513034G

Gligorijević B, Vilotijević MN, Scepanović M, Radovanović RV, Radović N. Cracking caused by cutting of plasma-sprayed hydroxyapatite coatings and its relation to the structural features of coatings deposited at different initial substrate temperatures. in Hemijska industrija. 2017;71(3):241-249.
doi:10.2298/HEMIND160513034G .

Gligorijević, Bojan, Vilotijević, Miroljub N., Scepanović, Maja, Radovanović, Radovan V., Radović, Nenad, "Cracking caused by cutting of plasma-sprayed hydroxyapatite coatings and its relation to the structural features of coatings deposited at different initial substrate temperatures" in Hemijska industrija, 71, no. 3 (2017):241-249,
https://doi.org/10.2298/HEMIND160513034G . .

TY  - JOUR
AU  - Gligorijević, Bojan
AU  - Vilotijević, Miroljub N.
AU  - Scepanović, Maja
AU  - Vidović, Dragoslav
AU  - Radović, Nenad
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3338
AB  - The aim of this work was to examine the dependence of the local surface structure (surface structural heterogeneity) on the local thickness (thickness uniformity) and structure properties along the thickness of hydroxyapatite coatings (HACs) deposited by using the high power (52 kW) laminar plasma jet. For the deposition process, a relatively small size of the feedstock hydroxyapatite powder (HAP) (33 mu m) was used. The HACs were deposited at different stand-off distances (SODs) (80, 100, and 150 mm) without preheating of substrates. The thickness measurements were performed by using the calibrated micrometer and light microscopy (LM). The surface micro-structure was analyzed by using the micro-Raman spectroscopy (MRS), whereas the micro-structure along the thickness of HACs was studied by using the MRS, X-ray powder diffractometry (XRPD), and LM (combined with chemical etching). The results showed a heterogeneous phase distribution on the surface of each HAC analyzed as well as the non-uniform thickness of HACs. Apparently, a correlation existed between the local surface structure and the local thickness of HACs. However, the MRS, XRPD, and LM analyses of micro-structure along the thickness of HACs indicated that the differences in the local surface structure could be related to the different recrystallization established during the plasma deposition process in the different parts along the thickness of each HAC analyzed.
PB  - Elsevier Science Sa, Lausanne
T2  - Journal of Alloys and Compounds
T1  - Surface structural heterogeneity of high power plasma-sprayed hydroxyapatite coatings
EP  - 430
SP  - 421
VL  - 687
DO  - 10.1016/j.jallcom.2016.06.163
ER  - 

@article{
author = "Gligorijević, Bojan and Vilotijević, Miroljub N. and Scepanović, Maja and Vidović, Dragoslav and Radović, Nenad",
year = "2016",
abstract = "The aim of this work was to examine the dependence of the local surface structure (surface structural heterogeneity) on the local thickness (thickness uniformity) and structure properties along the thickness of hydroxyapatite coatings (HACs) deposited by using the high power (52 kW) laminar plasma jet. For the deposition process, a relatively small size of the feedstock hydroxyapatite powder (HAP) (33 mu m) was used. The HACs were deposited at different stand-off distances (SODs) (80, 100, and 150 mm) without preheating of substrates. The thickness measurements were performed by using the calibrated micrometer and light microscopy (LM). The surface micro-structure was analyzed by using the micro-Raman spectroscopy (MRS), whereas the micro-structure along the thickness of HACs was studied by using the MRS, X-ray powder diffractometry (XRPD), and LM (combined with chemical etching). The results showed a heterogeneous phase distribution on the surface of each HAC analyzed as well as the non-uniform thickness of HACs. Apparently, a correlation existed between the local surface structure and the local thickness of HACs. However, the MRS, XRPD, and LM analyses of micro-structure along the thickness of HACs indicated that the differences in the local surface structure could be related to the different recrystallization established during the plasma deposition process in the different parts along the thickness of each HAC analyzed.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Journal of Alloys and Compounds",
title = "Surface structural heterogeneity of high power plasma-sprayed hydroxyapatite coatings",
pages = "430-421",
volume = "687",
doi = "10.1016/j.jallcom.2016.06.163"
}

Gligorijević, B., Vilotijević, M. N., Scepanović, M., Vidović, D.,& Radović, N.. (2016). Surface structural heterogeneity of high power plasma-sprayed hydroxyapatite coatings. in Journal of Alloys and Compounds
Elsevier Science Sa, Lausanne., 687, 421-430.
https://doi.org/10.1016/j.jallcom.2016.06.163

Gligorijević B, Vilotijević MN, Scepanović M, Vidović D, Radović N. Surface structural heterogeneity of high power plasma-sprayed hydroxyapatite coatings. in Journal of Alloys and Compounds. 2016;687:421-430.
doi:10.1016/j.jallcom.2016.06.163 .

Gligorijević, Bojan, Vilotijević, Miroljub N., Scepanović, Maja, Vidović, Dragoslav, Radović, Nenad, "Surface structural heterogeneity of high power plasma-sprayed hydroxyapatite coatings" in Journal of Alloys and Compounds, 687 (2016):421-430,
https://doi.org/10.1016/j.jallcom.2016.06.163 . .

TY  - JOUR
AU  - Gligorijević, Bojan
AU  - Vilotijević, Miroljub N.
AU  - Scepanović, Maja
AU  - Vuković, Nikola S.
AU  - Radović, Nenad
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3403
AB  - The aim of the present study was to investigate the influence of substrate preheating on the structural properties of hydroxyapatite coatings (HACs) deposited by using the high power (52 kW) laminar plasma jet. The deposition experiments were performed within the 20-200 degrees C temperature range at different stand-off distances. The structural properties in the thickness direction and at the surface of the HACs were investigated by using the micro-Raman spectroscopy, scanning electron microscopy coupled with energy dispersive spectrometry, and X-ray powder diffractometry. The deposition without the preheating of the substrate produced HACs with crystallinity gradient in the thickness direction. At the stand-off distance of 80 mm, the preheating of the substrate at 200 degrees C practically eliminated the crystallinity gradient. At distances from the coating/substrate interface shorter than similar to 100 mu m, the increase of crystallinity with the preheating of the substrate was dominantly attributed to the recrystallization of hydroxyl-rich ACP into HA. At longer distances and higher initial substrate temperatures (  gt  100 degrees C), the crystallinity changes were negligible, whereas the recrystallization of hydroxyl-deficient ACP into oxyapatite (OA) was also possible. The X-ray diffractometry indicated the deposition conditions under which a minimum residual stress was achieved. The results of the present study strongly suggested the relation between the ACP - gt  HA remystallization process and the bonding strength of the HACs.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings
EP  - 420
IS  - 1
SP  - 411
VL  - 42
DO  - 10.1016/j.ceramint.2015.08.125
ER  - 

@article{
author = "Gligorijević, Bojan and Vilotijević, Miroljub N. and Scepanović, Maja and Vuković, Nikola S. and Radović, Nenad",
year = "2016",
abstract = "The aim of the present study was to investigate the influence of substrate preheating on the structural properties of hydroxyapatite coatings (HACs) deposited by using the high power (52 kW) laminar plasma jet. The deposition experiments were performed within the 20-200 degrees C temperature range at different stand-off distances. The structural properties in the thickness direction and at the surface of the HACs were investigated by using the micro-Raman spectroscopy, scanning electron microscopy coupled with energy dispersive spectrometry, and X-ray powder diffractometry. The deposition without the preheating of the substrate produced HACs with crystallinity gradient in the thickness direction. At the stand-off distance of 80 mm, the preheating of the substrate at 200 degrees C practically eliminated the crystallinity gradient. At distances from the coating/substrate interface shorter than similar to 100 mu m, the increase of crystallinity with the preheating of the substrate was dominantly attributed to the recrystallization of hydroxyl-rich ACP into HA. At longer distances and higher initial substrate temperatures (  gt  100 degrees C), the crystallinity changes were negligible, whereas the recrystallization of hydroxyl-deficient ACP into oxyapatite (OA) was also possible. The X-ray diffractometry indicated the deposition conditions under which a minimum residual stress was achieved. The results of the present study strongly suggested the relation between the ACP - gt  HA remystallization process and the bonding strength of the HACs.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings",
pages = "420-411",
number = "1",
volume = "42",
doi = "10.1016/j.ceramint.2015.08.125"
}

Gligorijević, B., Vilotijević, M. N., Scepanović, M., Vuković, N. S.,& Radović, N.. (2016). Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings. in Ceramics International
Elsevier Sci Ltd, Oxford., 42(1), 411-420.
https://doi.org/10.1016/j.ceramint.2015.08.125

Gligorijević B, Vilotijević MN, Scepanović M, Vuković NS, Radović N. Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings. in Ceramics International. 2016;42(1):411-420.
doi:10.1016/j.ceramint.2015.08.125 .

Gligorijević, Bojan, Vilotijević, Miroljub N., Scepanović, Maja, Vuković, Nikola S., Radović, Nenad, "Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings" in Ceramics International, 42, no. 1 (2016):411-420,
https://doi.org/10.1016/j.ceramint.2015.08.125 . .

TY  - CONF
AU  - Radojković, Bojana M.
AU  - Krmar, Marija
AU  - Vilotijević, Miroljub N.
AU  - Gligorijević, Bojan R.
AU  - Alil, Ana
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6187
AB  - The morphology and phase composition of the diamond-like carbon (DLC) structures as a function of a deposition process parameters are investigated. The DLC was deposited in the low-pressure oxy-acetylene flat flame onto molybdenium substrates. It was done with the designed flame burner by spreading the flame over the area of 40 mm in diameter with the overall acetylene and oxygen flow up to 4 l/min and by changing the substrate distance and the O2/C2H2 ratio. The morphology and the phase composition of the DLC coatings sighnificantly depend on the deposition parameters, especially on the O2/C2H2 ratio.
PB  - Institut za Tehničke nauke SANU Beograd, Beograd, Srbija
C3  - Joint Event of the Eleventh Young Researchers’ Conference: Materials Science and Engineering and The First European Early Stage Researchers’ Conference on Hydrogen Storage: Program and the Book of Abstracts
T1  - Deposition of the DLC Structures In The Low-pressure Oxy-acetylene Flat Flame
SP  - 62
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6187
ER  - 

@conference{
author = "Radojković, Bojana M. and Krmar, Marija and Vilotijević, Miroljub N. and Gligorijević, Bojan R. and Alil, Ana",
year = "2012",
abstract = "The morphology and phase composition of the diamond-like carbon (DLC) structures as a function of a deposition process parameters are investigated. The DLC was deposited in the low-pressure oxy-acetylene flat flame onto molybdenium substrates. It was done with the designed flame burner by spreading the flame over the area of 40 mm in diameter with the overall acetylene and oxygen flow up to 4 l/min and by changing the substrate distance and the O2/C2H2 ratio. The morphology and the phase composition of the DLC coatings sighnificantly depend on the deposition parameters, especially on the O2/C2H2 ratio.",
publisher = "Institut za Tehničke nauke SANU Beograd, Beograd, Srbija",
journal = "Joint Event of the Eleventh Young Researchers’ Conference: Materials Science and Engineering and The First European Early Stage Researchers’ Conference on Hydrogen Storage: Program and the Book of Abstracts",
title = "Deposition of the DLC Structures In The Low-pressure Oxy-acetylene Flat Flame",
pages = "62",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6187"
}

Radojković, B. M., Krmar, M., Vilotijević, M. N., Gligorijević, B. R.,& Alil, A.. (2012). Deposition of the DLC Structures In The Low-pressure Oxy-acetylene Flat Flame. in Joint Event of the Eleventh Young Researchers’ Conference: Materials Science and Engineering and The First European Early Stage Researchers’ Conference on Hydrogen Storage: Program and the Book of Abstracts
Institut za Tehničke nauke SANU Beograd, Beograd, Srbija., 62.
https://hdl.handle.net/21.15107/rcub_technorep_6187

Radojković BM, Krmar M, Vilotijević MN, Gligorijević BR, Alil A. Deposition of the DLC Structures In The Low-pressure Oxy-acetylene Flat Flame. in Joint Event of the Eleventh Young Researchers’ Conference: Materials Science and Engineering and The First European Early Stage Researchers’ Conference on Hydrogen Storage: Program and the Book of Abstracts. 2012;:62.
https://hdl.handle.net/21.15107/rcub_technorep_6187 .

Radojković, Bojana M., Krmar, Marija, Vilotijević, Miroljub N., Gligorijević, Bojan R., Alil, Ana, "Deposition of the DLC Structures In The Low-pressure Oxy-acetylene Flat Flame" in Joint Event of the Eleventh Young Researchers’ Conference: Materials Science and Engineering and The First European Early Stage Researchers’ Conference on Hydrogen Storage: Program and the Book of Abstracts (2012):62,
https://hdl.handle.net/21.15107/rcub_technorep_6187 .