TY  - JOUR
AU  - Premović, Pavle I.
AU  - Nikolic, ND
AU  - Pavlović, Mirjana S.
AU  - Panov, KI
PY  - 2004
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2758
AB  - The Cretaceous-Tertiary, (KT) boundary transition at the Blake Nose Plateau recovered by ODP Lea 171B (site 1049, hole A. core 17X. section 2) contains an ejecta bed (thickness ca. 17 cm) marking a late Cretaceous asteroid impact. The nature and geochemical composition of this bed imply that it originated mainly from the target rocks of the Chicxulub impact site (Yucatan Peninsula, Mexico). the site of the presumed asteroid impact. The ejecta bed of hole 1049A contains relatively high concentrations of Ni (up to 165 ppm) within the carbonate fraction. It is reasoned that this enhancement represents a sudden and rapid airfall of high cosmogenic Ni into he Blake Nose Basin. The source of the metal was the Chicxulub impacting (carbonaceous) chondrite. It is suggested that many calcareous planktons in the KT ocean surface water of the Blake Nose Plateau were probably vulnerable to the high influx of superacid rainfall and associated toxic metals (e.g., Ni) created by the impact.
T2  - Journal of the Serbian Chemical Society
T1  - Geochemistry of the Cretaceous-Tertiary transition boundary at Blake Nose (NW Atlantic): Cosmogenic Ni
VL  - 69
IS  - 3
SP  - 205
EP  - 223
DO  - 10.2298/JSC0403205P
ER  - 

@article{
author = "Premović, Pavle I. and Nikolic, ND and Pavlović, Mirjana S. and Panov, KI",
year = "2004",
abstract = "The Cretaceous-Tertiary, (KT) boundary transition at the Blake Nose Plateau recovered by ODP Lea 171B (site 1049, hole A. core 17X. section 2) contains an ejecta bed (thickness ca. 17 cm) marking a late Cretaceous asteroid impact. The nature and geochemical composition of this bed imply that it originated mainly from the target rocks of the Chicxulub impact site (Yucatan Peninsula, Mexico). the site of the presumed asteroid impact. The ejecta bed of hole 1049A contains relatively high concentrations of Ni (up to 165 ppm) within the carbonate fraction. It is reasoned that this enhancement represents a sudden and rapid airfall of high cosmogenic Ni into he Blake Nose Basin. The source of the metal was the Chicxulub impacting (carbonaceous) chondrite. It is suggested that many calcareous planktons in the KT ocean surface water of the Blake Nose Plateau were probably vulnerable to the high influx of superacid rainfall and associated toxic metals (e.g., Ni) created by the impact.",
journal = "Journal of the Serbian Chemical Society",
title = "Geochemistry of the Cretaceous-Tertiary transition boundary at Blake Nose (NW Atlantic): Cosmogenic Ni",
volume = "69",
number = "3",
pages = "205-223",
doi = "10.2298/JSC0403205P"
}

Premović, P. I., Nikolic, N., Pavlović, M. S.,& Panov, K.. (2004). Geochemistry of the Cretaceous-Tertiary transition boundary at Blake Nose (NW Atlantic): Cosmogenic Ni. in Journal of the Serbian Chemical Society, 69(3), 205-223.
https://doi.org/10.2298/JSC0403205P

Premović PI, Nikolic N, Pavlović MS, Panov K. Geochemistry of the Cretaceous-Tertiary transition boundary at Blake Nose (NW Atlantic): Cosmogenic Ni. in Journal of the Serbian Chemical Society. 2004;69(3):205-223.
doi:10.2298/JSC0403205P .

Premović, Pavle I., Nikolic, ND, Pavlović, Mirjana S., Panov, KI, "Geochemistry of the Cretaceous-Tertiary transition boundary at Blake Nose (NW Atlantic): Cosmogenic Ni" in Journal of the Serbian Chemical Society, 69, no. 3 (2004):205-223,
https://doi.org/10.2298/JSC0403205P . .

TY  - JOUR
AU  - Nikolic, ND
AU  - Rakočević, Zlatko Lj.
AU  - Popov, KI
PY  - 2004
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2779
AB  - Reflection and structural analyses of different copper and zinc coatings were performed. The copper coatings were electrodeposited from a sulfate solution in the presence of thiourea, as well as in the presence of modified polyglycol ether, PEG 6000 and 3-mercaptopropanesulfonate. The zinc coating was electrodeposited from a sulfate solution in the presence of a dextrin/salicylaldehyde mixture. They were examined by STM and X-ray diffraction analysis, and measurements of the reflection of light from their surfaces were taken. The mean sizes of atomically flat parts of these surfaces were estimated by the STM software measurements, using options for the determination of the autocovariance function and the power spectral density function. It was shown that the mean sizes of atomically flat parts of the copper coatings were several times greater than the mean size of atomically flat parts of the zinc coating. This difference probably leads to the difference in the maximum degrees of mirror reflection between copper and zinc coatings.
T2  - Journal of Solid State Electrochemistry
T1  - Reflection and structural analyses of mirror-bright metal coatings
VL  - 8
IS  - 8
SP  - 526
EP  - 531
DO  - 10.1007/s10008-003-0467-8
ER  - 

@article{
author = "Nikolic, ND and Rakočević, Zlatko Lj. and Popov, KI",
year = "2004",
abstract = "Reflection and structural analyses of different copper and zinc coatings were performed. The copper coatings were electrodeposited from a sulfate solution in the presence of thiourea, as well as in the presence of modified polyglycol ether, PEG 6000 and 3-mercaptopropanesulfonate. The zinc coating was electrodeposited from a sulfate solution in the presence of a dextrin/salicylaldehyde mixture. They were examined by STM and X-ray diffraction analysis, and measurements of the reflection of light from their surfaces were taken. The mean sizes of atomically flat parts of these surfaces were estimated by the STM software measurements, using options for the determination of the autocovariance function and the power spectral density function. It was shown that the mean sizes of atomically flat parts of the copper coatings were several times greater than the mean size of atomically flat parts of the zinc coating. This difference probably leads to the difference in the maximum degrees of mirror reflection between copper and zinc coatings.",
journal = "Journal of Solid State Electrochemistry",
title = "Reflection and structural analyses of mirror-bright metal coatings",
volume = "8",
number = "8",
pages = "526-531",
doi = "10.1007/s10008-003-0467-8"
}

Nikolic, N., Rakočević, Z. Lj.,& Popov, K.. (2004). Reflection and structural analyses of mirror-bright metal coatings. in Journal of Solid State Electrochemistry, 8(8), 526-531.
https://doi.org/10.1007/s10008-003-0467-8

Nikolic N, Rakočević ZL, Popov K. Reflection and structural analyses of mirror-bright metal coatings. in Journal of Solid State Electrochemistry. 2004;8(8):526-531.
doi:10.1007/s10008-003-0467-8 .

Nikolic, ND, Rakočević, Zlatko Lj., Popov, KI, "Reflection and structural analyses of mirror-bright metal coatings" in Journal of Solid State Electrochemistry, 8, no. 8 (2004):526-531,
https://doi.org/10.1007/s10008-003-0467-8 . .

TY  - JOUR
AU  - Nikolic, ND
AU  - Novaković, G
AU  - Rakočević, Zlatko Lj.
AU  - Durovic, DR
AU  - Popov, KI
PY  - 2002
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2556
AB  - Reflection and structural analyses of different copper and zinc coatings were performed. The coatings of copper obtained were from acid sulfate solutions in the absence and presence of thiourea. The coatings of zinc were obtained from acid sulfate solutions in the absence and presence of dextrin and furfural. They were examined by STM, X-ray diffraction (XRD) analysis, and measurements of the reflection of light from their surfaces were taken. Reflection of light from zinc and copper coatings obtained from corresponding pure sulfate solutions was mostly diffuse reflection. The copper coating obtained in the presence of thiourea and the zinc coating obtained in the presence of dextrin and furfural showed a high degree of mirror reflection, and based on structural analysis are characterised as mirror bright metal surfaces. (C) 2002 Elsevier Science B.V. All rights reserved.
T2  - Surface and Coatings Technology
T1  - Comparative reflection and structural analyses of copper and zinc coatings electrodeposited from acid sulfate solutions with and without additives
VL  - 161
IS  - 2-3
SP  - 188
EP  - 194
DO  - 10.1016/S0257-8972(02)00517-0
ER  - 

@article{
author = "Nikolic, ND and Novaković, G and Rakočević, Zlatko Lj. and Durovic, DR and Popov, KI",
year = "2002",
abstract = "Reflection and structural analyses of different copper and zinc coatings were performed. The coatings of copper obtained were from acid sulfate solutions in the absence and presence of thiourea. The coatings of zinc were obtained from acid sulfate solutions in the absence and presence of dextrin and furfural. They were examined by STM, X-ray diffraction (XRD) analysis, and measurements of the reflection of light from their surfaces were taken. Reflection of light from zinc and copper coatings obtained from corresponding pure sulfate solutions was mostly diffuse reflection. The copper coating obtained in the presence of thiourea and the zinc coating obtained in the presence of dextrin and furfural showed a high degree of mirror reflection, and based on structural analysis are characterised as mirror bright metal surfaces. (C) 2002 Elsevier Science B.V. All rights reserved.",
journal = "Surface and Coatings Technology",
title = "Comparative reflection and structural analyses of copper and zinc coatings electrodeposited from acid sulfate solutions with and without additives",
volume = "161",
number = "2-3",
pages = "188-194",
doi = "10.1016/S0257-8972(02)00517-0"
}

Nikolic, N., Novaković, G., Rakočević, Z. Lj., Durovic, D.,& Popov, K.. (2002). Comparative reflection and structural analyses of copper and zinc coatings electrodeposited from acid sulfate solutions with and without additives. in Surface and Coatings Technology, 161(2-3), 188-194.
https://doi.org/10.1016/S0257-8972(02)00517-0

Nikolic N, Novaković G, Rakočević ZL, Durovic D, Popov K. Comparative reflection and structural analyses of copper and zinc coatings electrodeposited from acid sulfate solutions with and without additives. in Surface and Coatings Technology. 2002;161(2-3):188-194.
doi:10.1016/S0257-8972(02)00517-0 .

Nikolic, ND, Novaković, G, Rakočević, Zlatko Lj., Durovic, DR, Popov, KI, "Comparative reflection and structural analyses of copper and zinc coatings electrodeposited from acid sulfate solutions with and without additives" in Surface and Coatings Technology, 161, no. 2-3 (2002):188-194,
https://doi.org/10.1016/S0257-8972(02)00517-0 . .

TY  - JOUR
AU  - Popov, KI
AU  - Nikolic, ND
AU  - Rakočević, Zlatko Lj.
PY  - 2002
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2598
AB  - Electrochemically deposited copper powders, which are formed of particles of different size and morphology, are characterized by sonic properties like specific surface and apparent density. A procedure of the determination of a representative powder particle, exhibiting the same values of specific surface and apparent density as the powder is proposed. The proposed procedure also permints an explanation of the branching of copper dendrites.
T2  - Journal of the Serbian Chemical Society
T1  - The respresentative particle of copper powder and branching of copper dendrites
VL  - 67
IS  - 12
SP  - 861
EP  - 866
DO  - 10.2298/JSC0212861P
ER  - 

@article{
author = "Popov, KI and Nikolic, ND and Rakočević, Zlatko Lj.",
year = "2002",
abstract = "Electrochemically deposited copper powders, which are formed of particles of different size and morphology, are characterized by sonic properties like specific surface and apparent density. A procedure of the determination of a representative powder particle, exhibiting the same values of specific surface and apparent density as the powder is proposed. The proposed procedure also permints an explanation of the branching of copper dendrites.",
journal = "Journal of the Serbian Chemical Society",
title = "The respresentative particle of copper powder and branching of copper dendrites",
volume = "67",
number = "12",
pages = "861-866",
doi = "10.2298/JSC0212861P"
}

Popov, K., Nikolic, N.,& Rakočević, Z. Lj.. (2002). The respresentative particle of copper powder and branching of copper dendrites. in Journal of the Serbian Chemical Society, 67(12), 861-866.
https://doi.org/10.2298/JSC0212861P

Popov K, Nikolic N, Rakočević ZL. The respresentative particle of copper powder and branching of copper dendrites. in Journal of the Serbian Chemical Society. 2002;67(12):861-866.
doi:10.2298/JSC0212861P .

Popov, KI, Nikolic, ND, Rakočević, Zlatko Lj., "The respresentative particle of copper powder and branching of copper dendrites" in Journal of the Serbian Chemical Society, 67, no. 12 (2002):861-866,
https://doi.org/10.2298/JSC0212861P . .

TY  - JOUR
AU  - Popov, KI
AU  - Nikolic, ND
AU  - Rakočević, Zlatko Lj.
PY  - 2002
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2595
AB  - In metal electrodeposition in the limiting diffusion current density range, the deposition current density remains constant regardless of the deposition overpotential used, At the same time, die larger the deposition overpotential is the more disperse is the formed deposit, which is characterised by an increase specific surface. The difference in die specific surface of disperse deposits obtained at two different overpotentials; in the limiting diffusion current density range is correlated with the difference between the deposition overpotentials. A method for the estimation of the surface tension of solid copper in copper sulfate solutions is also proposed.
T2  - Journal of the Serbian Chemical Society
T1  - The estimation of solid copper surface tension in copper sulfate solutions
VL  - 67
IS  - 11
SP  - 769
EP  - 775
DO  - 10.2298/JSC0211769P
ER  - 

@article{
author = "Popov, KI and Nikolic, ND and Rakočević, Zlatko Lj.",
year = "2002",
abstract = "In metal electrodeposition in the limiting diffusion current density range, the deposition current density remains constant regardless of the deposition overpotential used, At the same time, die larger the deposition overpotential is the more disperse is the formed deposit, which is characterised by an increase specific surface. The difference in die specific surface of disperse deposits obtained at two different overpotentials; in the limiting diffusion current density range is correlated with the difference between the deposition overpotentials. A method for the estimation of the surface tension of solid copper in copper sulfate solutions is also proposed.",
journal = "Journal of the Serbian Chemical Society",
title = "The estimation of solid copper surface tension in copper sulfate solutions",
volume = "67",
number = "11",
pages = "769-775",
doi = "10.2298/JSC0211769P"
}

Popov, K., Nikolic, N.,& Rakočević, Z. Lj.. (2002). The estimation of solid copper surface tension in copper sulfate solutions. in Journal of the Serbian Chemical Society, 67(11), 769-775.
https://doi.org/10.2298/JSC0211769P

Popov K, Nikolic N, Rakočević ZL. The estimation of solid copper surface tension in copper sulfate solutions. in Journal of the Serbian Chemical Society. 2002;67(11):769-775.
doi:10.2298/JSC0211769P .

Popov, KI, Nikolic, ND, Rakočević, Zlatko Lj., "The estimation of solid copper surface tension in copper sulfate solutions" in Journal of the Serbian Chemical Society, 67, no. 11 (2002):769-775,
https://doi.org/10.2298/JSC0211769P . .

TY  - JOUR
AU  - Popov, KI
AU  - Nikolic, ND
AU  - Rakočević, Zlatko Lj.
PY  - 2002
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2548
AB  - A possible way for the estimation of the interfacial energy of the copper - copper sulphate solution interface is proposed. The estimated value of (2.7 +/- 0.3) J cm(-2) and the derived equations which relate the specific surface of copper powder to the deposition conditions permit an estimation of the specific surface of copper powderc The agreement between the estimated value and literature data is very good.
T2  - Journal of the Serbian Chemical Society
T1  - An estimation of the interfacial energy of the copper-copper sulphate solution interface and of the specific surface of copper powder
VL  - 67
IS  - 8-9
SP  - 635
EP  - 638
DO  - 10.2298/JSC0209635P
ER  - 

@article{
author = "Popov, KI and Nikolic, ND and Rakočević, Zlatko Lj.",
year = "2002",
abstract = "A possible way for the estimation of the interfacial energy of the copper - copper sulphate solution interface is proposed. The estimated value of (2.7 +/- 0.3) J cm(-2) and the derived equations which relate the specific surface of copper powder to the deposition conditions permit an estimation of the specific surface of copper powderc The agreement between the estimated value and literature data is very good.",
journal = "Journal of the Serbian Chemical Society",
title = "An estimation of the interfacial energy of the copper-copper sulphate solution interface and of the specific surface of copper powder",
volume = "67",
number = "8-9",
pages = "635-638",
doi = "10.2298/JSC0209635P"
}

Popov, K., Nikolic, N.,& Rakočević, Z. Lj.. (2002). An estimation of the interfacial energy of the copper-copper sulphate solution interface and of the specific surface of copper powder. in Journal of the Serbian Chemical Society, 67(8-9), 635-638.
https://doi.org/10.2298/JSC0209635P

Popov K, Nikolic N, Rakočević ZL. An estimation of the interfacial energy of the copper-copper sulphate solution interface and of the specific surface of copper powder. in Journal of the Serbian Chemical Society. 2002;67(8-9):635-638.
doi:10.2298/JSC0209635P .

Popov, KI, Nikolic, ND, Rakočević, Zlatko Lj., "An estimation of the interfacial energy of the copper-copper sulphate solution interface and of the specific surface of copper powder" in Journal of the Serbian Chemical Society, 67, no. 8-9 (2002):635-638,
https://doi.org/10.2298/JSC0209635P . .

TY  - JOUR
AU  - Nikolic, ND
AU  - Rakočević, Zlatko Lj.
AU  - Durovic, DR
AU  - Popov, KI
PY  - 2002
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2531
AB  - The reflection and structural characteristics of the nickel coatings obtained in the presence of a basic brightening addition agent only, and of both a basic and top brightening, addition agent arc examined. It is shown that the nickel coating obtained in the presence of both a basic and top brightening addition agent fulfilled the conditions to be characterized as a mirror bright metal surface. The nickel coating obtained in the presence of a basic brightening, addition agent only is characterized as a semi-bright metal surface.
T2  - Journal of the Serbian Chemical Society
T1  - Reflection and structural characteristics of semi-bright and mirror bright nickel coatings
VL  - 67
IS  - 6
SP  - 437
EP  - 443
DO  - 10.2298/JSC0206437N
ER  - 

@article{
author = "Nikolic, ND and Rakočević, Zlatko Lj. and Durovic, DR and Popov, KI",
year = "2002",
abstract = "The reflection and structural characteristics of the nickel coatings obtained in the presence of a basic brightening addition agent only, and of both a basic and top brightening, addition agent arc examined. It is shown that the nickel coating obtained in the presence of both a basic and top brightening addition agent fulfilled the conditions to be characterized as a mirror bright metal surface. The nickel coating obtained in the presence of a basic brightening, addition agent only is characterized as a semi-bright metal surface.",
journal = "Journal of the Serbian Chemical Society",
title = "Reflection and structural characteristics of semi-bright and mirror bright nickel coatings",
volume = "67",
number = "6",
pages = "437-443",
doi = "10.2298/JSC0206437N"
}

Nikolic, N., Rakočević, Z. Lj., Durovic, D.,& Popov, K.. (2002). Reflection and structural characteristics of semi-bright and mirror bright nickel coatings. in Journal of the Serbian Chemical Society, 67(6), 437-443.
https://doi.org/10.2298/JSC0206437N

Nikolic N, Rakočević ZL, Durovic D, Popov K. Reflection and structural characteristics of semi-bright and mirror bright nickel coatings. in Journal of the Serbian Chemical Society. 2002;67(6):437-443.
doi:10.2298/JSC0206437N .

Nikolic, ND, Rakočević, Zlatko Lj., Durovic, DR, Popov, KI, "Reflection and structural characteristics of semi-bright and mirror bright nickel coatings" in Journal of the Serbian Chemical Society, 67, no. 6 (2002):437-443,
https://doi.org/10.2298/JSC0206437N . .

TY  - JOUR
AU  - Premović, Pavle I.
AU  - Nikolic, ND
AU  - Pavlović, Mirjana S.
AU  - Todorović, PZ
AU  - Đorđević, Dragan M.
AU  - Nikolic, RS
AU  - Lopez, Liliana
AU  - LoMonaco, Salvador
PY  - 2001
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2472
AB  - Trace metals in the four discrete layers of the Cretaceous-Tertiary boundary (Fiskeler) at Stevns Klint (Denmark) are relatively well studied, yet much remains to be learned about them. Therefore, an integrated study of the trace (meteoritic Ir, partly meteoritic Cr/Ni/Co/Au and terrestrial Zn/Cu/La/Ce/Nd/Sm/Eu/Tb/Yb/Ta/Th) metals in the basal black marl of Fiskeler and in its (carbonate, HCl-soluble, smectite, HCl-insoluble, silicate and kerogen) fractions was undertaken. The mineralogy of the marl is comparatively simple, authigenic calcite (mainly derived from planktonic marine algae: coccoliths), detrital Mg-smectite and quartz being the principal components, with lesser amounts of kerogen, Fe3+-oxides, pyrite, ilite and feldspar. Selective leaching procedures were used to establish geochemical associations and specific mineralogical locations of the trace metals. The results identified the main locations of the major trace metals (Cr/Ni/Co/Zn/Cu/Au), They occur mainly in the smectite and, to a lesser extent, in the biogenic calcite (Ni/Co/Zn) and kerogen (Ir/Au). The trace metal data are in accordance with the hypothesis that substantial proportions of Cr/Ni/Co/Zn/Cu/Ir/Au were probably contained in the detrital smectite arriving at the site of the deposition. In a general discussion of the results, a geochemical model describing the incorporation of trace metals in the smectite is presented, based on the weathering/trasport of the clay by (impact-induced) acid surface waters and the adsorption of trace metal ions by the smectite particles/colloids in the acidic solution of nearby oxic soil. The distribution/enrichment patterns of Cr/Ni/Co/Zn of the basal black marl and higher Fiskeler layers indicate, on the other hand, that notable proportions of these metals were incorporated into the smectite structure during the formation of the clay. The trace metal data are also considered in light of previously published paleoecological and geochemical information for Fiskeler. It is proposed, for example, that the local (impact-induced) superacid rainfall and wildfires played an important role in providing appropriate humics (i.e. appropriate organics of decaying land green plants) having porphyrin stuctures for the formation of kerogen (enriched with Cu2+-porphyrins). In addition, it has been suggested that the biogenic calcite with high Ni is probably a product of the metabolic uptake of boundary seawater (enriched with this metal) by the coccoliths. The metal enrichment of the seawater was created by a sudden and high influx of (apparently mainly meteoritic) Ni: airborne and laterally redeposited (by the acid surface/river waters) from a nearby soil. Lastly, the lateral distribution of kerogen (enriched with Cu2+-porpyhyrins) supports an earlier interpretation presented by Hultenberg(1,2) that the alleged (Nye Klov/Dania) boundaries in northwestern Denmark represent erosion and subsequent redeposition of Fiskeler in eastern Denmark.
T2  - Journal of the Serbian Chemical Society
T1  - The Cretaceous-Tertiary boundary Fiskeler at Stevns Klint, Denmark: the geochemistry of the major trace metals
VL  - 66
IS  - 10
SP  - 647
EP  - 670
UR  - https://hdl.handle.net/21.15107/rcub_vinar_2472
ER  - 

@article{
author = "Premović, Pavle I. and Nikolic, ND and Pavlović, Mirjana S. and Todorović, PZ and Đorđević, Dragan M. and Nikolic, RS and Lopez, Liliana and LoMonaco, Salvador",
year = "2001",
abstract = "Trace metals in the four discrete layers of the Cretaceous-Tertiary boundary (Fiskeler) at Stevns Klint (Denmark) are relatively well studied, yet much remains to be learned about them. Therefore, an integrated study of the trace (meteoritic Ir, partly meteoritic Cr/Ni/Co/Au and terrestrial Zn/Cu/La/Ce/Nd/Sm/Eu/Tb/Yb/Ta/Th) metals in the basal black marl of Fiskeler and in its (carbonate, HCl-soluble, smectite, HCl-insoluble, silicate and kerogen) fractions was undertaken. The mineralogy of the marl is comparatively simple, authigenic calcite (mainly derived from planktonic marine algae: coccoliths), detrital Mg-smectite and quartz being the principal components, with lesser amounts of kerogen, Fe3+-oxides, pyrite, ilite and feldspar. Selective leaching procedures were used to establish geochemical associations and specific mineralogical locations of the trace metals. The results identified the main locations of the major trace metals (Cr/Ni/Co/Zn/Cu/Au), They occur mainly in the smectite and, to a lesser extent, in the biogenic calcite (Ni/Co/Zn) and kerogen (Ir/Au). The trace metal data are in accordance with the hypothesis that substantial proportions of Cr/Ni/Co/Zn/Cu/Ir/Au were probably contained in the detrital smectite arriving at the site of the deposition. In a general discussion of the results, a geochemical model describing the incorporation of trace metals in the smectite is presented, based on the weathering/trasport of the clay by (impact-induced) acid surface waters and the adsorption of trace metal ions by the smectite particles/colloids in the acidic solution of nearby oxic soil. The distribution/enrichment patterns of Cr/Ni/Co/Zn of the basal black marl and higher Fiskeler layers indicate, on the other hand, that notable proportions of these metals were incorporated into the smectite structure during the formation of the clay. The trace metal data are also considered in light of previously published paleoecological and geochemical information for Fiskeler. It is proposed, for example, that the local (impact-induced) superacid rainfall and wildfires played an important role in providing appropriate humics (i.e. appropriate organics of decaying land green plants) having porphyrin stuctures for the formation of kerogen (enriched with Cu2+-porphyrins). In addition, it has been suggested that the biogenic calcite with high Ni is probably a product of the metabolic uptake of boundary seawater (enriched with this metal) by the coccoliths. The metal enrichment of the seawater was created by a sudden and high influx of (apparently mainly meteoritic) Ni: airborne and laterally redeposited (by the acid surface/river waters) from a nearby soil. Lastly, the lateral distribution of kerogen (enriched with Cu2+-porpyhyrins) supports an earlier interpretation presented by Hultenberg(1,2) that the alleged (Nye Klov/Dania) boundaries in northwestern Denmark represent erosion and subsequent redeposition of Fiskeler in eastern Denmark.",
journal = "Journal of the Serbian Chemical Society",
title = "The Cretaceous-Tertiary boundary Fiskeler at Stevns Klint, Denmark: the geochemistry of the major trace metals",
volume = "66",
number = "10",
pages = "647-670",
url = "https://hdl.handle.net/21.15107/rcub_vinar_2472"
}

Premović, P. I., Nikolic, N., Pavlović, M. S., Todorović, P., Đorđević, D. M., Nikolic, R., Lopez, L.,& LoMonaco, S.. (2001). The Cretaceous-Tertiary boundary Fiskeler at Stevns Klint, Denmark: the geochemistry of the major trace metals. in Journal of the Serbian Chemical Society, 66(10), 647-670.
https://hdl.handle.net/21.15107/rcub_vinar_2472

Premović PI, Nikolic N, Pavlović MS, Todorović P, Đorđević DM, Nikolic R, Lopez L, LoMonaco S. The Cretaceous-Tertiary boundary Fiskeler at Stevns Klint, Denmark: the geochemistry of the major trace metals. in Journal of the Serbian Chemical Society. 2001;66(10):647-670.
https://hdl.handle.net/21.15107/rcub_vinar_2472 .

Premović, Pavle I., Nikolic, ND, Pavlović, Mirjana S., Todorović, PZ, Đorđević, Dragan M., Nikolic, RS, Lopez, Liliana, LoMonaco, Salvador, "The Cretaceous-Tertiary boundary Fiskeler at Stevns Klint, Denmark: the geochemistry of the major trace metals" in Journal of the Serbian Chemical Society, 66, no. 10 (2001):647-670,
https://hdl.handle.net/21.15107/rcub_vinar_2472 .

TY  - JOUR
AU  - Nikolic, ND
AU  - Rakočević, Zlatko Lj.
AU  - Popov, KI
PY  - 2001
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2473
AB  - In this work, the structure of a silver mirror surface was examined by the STM technique. It was shown that the Structural characteristics which enable a high degree of mirror reflection from this surface, which is very close to the ideal reflectivity of silver, are: flat and mutually parallel parts of the surface which are smooth on the atomic level, and distances between adjacent flat parts which state several atomic diameters.
T2  - Journal of the Serbian Chemical Society
T1  - The STM analysis of a silver mirror surface
VL  - 66
IS  - 10
SP  - 723
EP  - 727
UR  - https://hdl.handle.net/21.15107/rcub_vinar_2473
ER  - 

@article{
author = "Nikolic, ND and Rakočević, Zlatko Lj. and Popov, KI",
year = "2001",
abstract = "In this work, the structure of a silver mirror surface was examined by the STM technique. It was shown that the Structural characteristics which enable a high degree of mirror reflection from this surface, which is very close to the ideal reflectivity of silver, are: flat and mutually parallel parts of the surface which are smooth on the atomic level, and distances between adjacent flat parts which state several atomic diameters.",
journal = "Journal of the Serbian Chemical Society",
title = "The STM analysis of a silver mirror surface",
volume = "66",
number = "10",
pages = "723-727",
url = "https://hdl.handle.net/21.15107/rcub_vinar_2473"
}

Nikolic, N., Rakočević, Z. Lj.,& Popov, K.. (2001). The STM analysis of a silver mirror surface. in Journal of the Serbian Chemical Society, 66(10), 723-727.
https://hdl.handle.net/21.15107/rcub_vinar_2473

Nikolic N, Rakočević ZL, Popov K. The STM analysis of a silver mirror surface. in Journal of the Serbian Chemical Society. 2001;66(10):723-727.
https://hdl.handle.net/21.15107/rcub_vinar_2473 .

Nikolic, ND, Rakočević, Zlatko Lj., Popov, KI, "The STM analysis of a silver mirror surface" in Journal of the Serbian Chemical Society, 66, no. 10 (2001):723-727,
https://hdl.handle.net/21.15107/rcub_vinar_2473 .

TY  - JOUR
AU  - Nikolic, ND
AU  - Rakočević, Zlatko Lj.
AU  - Popov, KI
PY  - 2001
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2479
AB  - In this work, the structures of copper surfaces polished mechanically and polished both mechanically and electrochemically, as well as copper coatings obtained in the presence of basic and top brightening addition agents were examined and compared with the structure of a silver mirror. It was shown by the STM technique that the structural characteristics important for the mirror brightness of the copper surface polished both mechanically and electrochemically and the copper coating are: (1) flat and mutually parallel parts of the surface which are smooth on the atomic level and (2) distances between adjacent flat parts are comparative with the distances between the adjacent flat parts of a silver mirror. Also, on the basis of the STM analysis, a mathematical model treating brightness from the point of view of geometrical optics was developed. X-ray diffraction analysis of the copper surfaces showed that mirror brightness is not associated directly with the degree of preferred orientation. (C) 2001 Elsevier Science B.V. All rights reserved.
T2  - Journal of Electroanalytical Chemistry
T1  - Structural characteristics of bright copper surfaces
VL  - 514
IS  - 1-2
SP  - 56
EP  - 66
DO  - 10.1016/S0022-0728(01)00626-X
ER  - 

@article{
author = "Nikolic, ND and Rakočević, Zlatko Lj. and Popov, KI",
year = "2001",
abstract = "In this work, the structures of copper surfaces polished mechanically and polished both mechanically and electrochemically, as well as copper coatings obtained in the presence of basic and top brightening addition agents were examined and compared with the structure of a silver mirror. It was shown by the STM technique that the structural characteristics important for the mirror brightness of the copper surface polished both mechanically and electrochemically and the copper coating are: (1) flat and mutually parallel parts of the surface which are smooth on the atomic level and (2) distances between adjacent flat parts are comparative with the distances between the adjacent flat parts of a silver mirror. Also, on the basis of the STM analysis, a mathematical model treating brightness from the point of view of geometrical optics was developed. X-ray diffraction analysis of the copper surfaces showed that mirror brightness is not associated directly with the degree of preferred orientation. (C) 2001 Elsevier Science B.V. All rights reserved.",
journal = "Journal of Electroanalytical Chemistry",
title = "Structural characteristics of bright copper surfaces",
volume = "514",
number = "1-2",
pages = "56-66",
doi = "10.1016/S0022-0728(01)00626-X"
}

Nikolic, N., Rakočević, Z. Lj.,& Popov, K.. (2001). Structural characteristics of bright copper surfaces. in Journal of Electroanalytical Chemistry, 514(1-2), 56-66.
https://doi.org/10.1016/S0022-0728(01)00626-X

Nikolic N, Rakočević ZL, Popov K. Structural characteristics of bright copper surfaces. in Journal of Electroanalytical Chemistry. 2001;514(1-2):56-66.
doi:10.1016/S0022-0728(01)00626-X .

Nikolic, ND, Rakočević, Zlatko Lj., Popov, KI, "Structural characteristics of bright copper surfaces" in Journal of Electroanalytical Chemistry, 514, no. 1-2 (2001):56-66,
https://doi.org/10.1016/S0022-0728(01)00626-X . .

TY  - JOUR
AU  - Premović, Pavle I.
AU  - Nikolic, ND
AU  - Tonsa, Ivana R.
AU  - Pavlović, Mirjana S.
AU  - Premović, MP
AU  - Dulanovic, DT
PY  - 2000
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2341
AB  - High levels of copper(II) (Cu2+) were found with the major part ( GT 90%) of the total Cu located in the smectite (Cu: 175 ppm) and kerogen (Cu: up to 1000 ppm) of the basal black marl of the Cretaceous-Tertiary (KT) boundary informal type sedimentary rock: the Fish Clay at Stevns Klint, Denmark. Anomalous abundance (4000 ppm) of the kerogen Cu2+-porphyrins in this marl was detected by electron spin resonance. A model is proposed in which the enormous acid rains (caused by the KT asteroid impact) washed out the humics (already enriched with Cu2+/Cu2+-porphyrins) of the top horizon of the nearby oxic soil into the Fish Clay Basin during the KT event. (C) 2000 Elsevier Science B.V. All rights reserved.
T2  - Earth and Planetary Science Letters
T1  - Copper and copper(II) porphyrins of the Cretaceous-Tertiary boundary at Stevns Klint (Denmark)
VL  - 177
IS  - 1-2
SP  - 105
EP  - 118
DO  - 10.1016/S0012-821X(00)00030-3
ER  - 

@article{
author = "Premović, Pavle I. and Nikolic, ND and Tonsa, Ivana R. and Pavlović, Mirjana S. and Premović, MP and Dulanovic, DT",
year = "2000",
abstract = "High levels of copper(II) (Cu2+) were found with the major part ( GT 90%) of the total Cu located in the smectite (Cu: 175 ppm) and kerogen (Cu: up to 1000 ppm) of the basal black marl of the Cretaceous-Tertiary (KT) boundary informal type sedimentary rock: the Fish Clay at Stevns Klint, Denmark. Anomalous abundance (4000 ppm) of the kerogen Cu2+-porphyrins in this marl was detected by electron spin resonance. A model is proposed in which the enormous acid rains (caused by the KT asteroid impact) washed out the humics (already enriched with Cu2+/Cu2+-porphyrins) of the top horizon of the nearby oxic soil into the Fish Clay Basin during the KT event. (C) 2000 Elsevier Science B.V. All rights reserved.",
journal = "Earth and Planetary Science Letters",
title = "Copper and copper(II) porphyrins of the Cretaceous-Tertiary boundary at Stevns Klint (Denmark)",
volume = "177",
number = "1-2",
pages = "105-118",
doi = "10.1016/S0012-821X(00)00030-3"
}

Premović, P. I., Nikolic, N., Tonsa, I. R., Pavlović, M. S., Premović, M.,& Dulanovic, D.. (2000). Copper and copper(II) porphyrins of the Cretaceous-Tertiary boundary at Stevns Klint (Denmark). in Earth and Planetary Science Letters, 177(1-2), 105-118.
https://doi.org/10.1016/S0012-821X(00)00030-3

Premović PI, Nikolic N, Tonsa IR, Pavlović MS, Premović M, Dulanovic D. Copper and copper(II) porphyrins of the Cretaceous-Tertiary boundary at Stevns Klint (Denmark). in Earth and Planetary Science Letters. 2000;177(1-2):105-118.
doi:10.1016/S0012-821X(00)00030-3 .

Premović, Pavle I., Nikolic, ND, Tonsa, Ivana R., Pavlović, Mirjana S., Premović, MP, Dulanovic, DT, "Copper and copper(II) porphyrins of the Cretaceous-Tertiary boundary at Stevns Klint (Denmark)" in Earth and Planetary Science Letters, 177, no. 1-2 (2000):105-118,
https://doi.org/10.1016/S0012-821X(00)00030-3 . .

TY  - JOUR
AU  - Premović, Pavle I.
AU  - Allard, T
AU  - Nikolic, ND
AU  - Tonsa, Ivana R.
AU  - Pavlović, Mirjana S.
PY  - 2000
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2338
AB  - We describe a new, rapid method for determining the concentration of vanadyl porphyrins (VO2+-P) associated with the kerogen of bituminous sedimentary rocks using electron spin resonance (ESR). The method is simple, straightforward and inexpensive. Several concentrations of a vanadyl (VO2+) standard dissolved in glycerol-lignite mixture were prepared. The VO2+ concentrations ranged from 100 to 1000 ppm. The anisotropic ESR spectra of both the standards and kerogen samples were recorded at room temperature and the integrated areas of the pre-selected ESR line (attributed to nuclear spin m(t) = -5/2) were computed. The concentrations of VO2+ found in the kerogen samples were calculated using the relative ratio of the integrated areas for the standards and the kerogen samples. The VO2+-P concentrations of the kerogen materials were then calculated using 350 as the mean molecular weight of these species. Quantitative determination of VO2+-P in the kerogen fractions in the range of 800-8000 ppm and higher is feasible by the method reported. The method of analysis was also extended to the asphaltene samples (enriched with VO2+-P) and a coal sample containing non-porphyrin VO2+ associated with its organic fraction. (C) 2000 Elsevier Science Ltd. All rights reserved.
T2  - Fuel
T1  - Estimation of vanadyl porphyrin concentration in sedimentary kerogens and asphaltenes
VL  - 79
IS  - 7
SP  - 813
EP  - 819
DO  - 10.1016/S0016-2361(99)00205-7
ER  - 

@article{
author = "Premović, Pavle I. and Allard, T and Nikolic, ND and Tonsa, Ivana R. and Pavlović, Mirjana S.",
year = "2000",
abstract = "We describe a new, rapid method for determining the concentration of vanadyl porphyrins (VO2+-P) associated with the kerogen of bituminous sedimentary rocks using electron spin resonance (ESR). The method is simple, straightforward and inexpensive. Several concentrations of a vanadyl (VO2+) standard dissolved in glycerol-lignite mixture were prepared. The VO2+ concentrations ranged from 100 to 1000 ppm. The anisotropic ESR spectra of both the standards and kerogen samples were recorded at room temperature and the integrated areas of the pre-selected ESR line (attributed to nuclear spin m(t) = -5/2) were computed. The concentrations of VO2+ found in the kerogen samples were calculated using the relative ratio of the integrated areas for the standards and the kerogen samples. The VO2+-P concentrations of the kerogen materials were then calculated using 350 as the mean molecular weight of these species. Quantitative determination of VO2+-P in the kerogen fractions in the range of 800-8000 ppm and higher is feasible by the method reported. The method of analysis was also extended to the asphaltene samples (enriched with VO2+-P) and a coal sample containing non-porphyrin VO2+ associated with its organic fraction. (C) 2000 Elsevier Science Ltd. All rights reserved.",
journal = "Fuel",
title = "Estimation of vanadyl porphyrin concentration in sedimentary kerogens and asphaltenes",
volume = "79",
number = "7",
pages = "813-819",
doi = "10.1016/S0016-2361(99)00205-7"
}

Premović, P. I., Allard, T., Nikolic, N., Tonsa, I. R.,& Pavlović, M. S.. (2000). Estimation of vanadyl porphyrin concentration in sedimentary kerogens and asphaltenes. in Fuel, 79(7), 813-819.
https://doi.org/10.1016/S0016-2361(99)00205-7

Premović PI, Allard T, Nikolic N, Tonsa IR, Pavlović MS. Estimation of vanadyl porphyrin concentration in sedimentary kerogens and asphaltenes. in Fuel. 2000;79(7):813-819.
doi:10.1016/S0016-2361(99)00205-7 .

Premović, Pavle I., Allard, T, Nikolic, ND, Tonsa, Ivana R., Pavlović, Mirjana S., "Estimation of vanadyl porphyrin concentration in sedimentary kerogens and asphaltenes" in Fuel, 79, no. 7 (2000):813-819,
https://doi.org/10.1016/S0016-2361(99)00205-7 . .

TY  - JOUR
AU  - Nikolic, ND
AU  - Stojilkovic, ER
AU  - Đurović, Dejan R.
AU  - Pavlović, Miomir G.
AU  - Knežević, VR
PY  - 2000
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6300
AB  - The preferred orientations of copper deposits obtained from acid sulfate solutions were examined. Mat deposits obtained in the absence of the additives and in the presence of disodium 2-naphthol-3,6-disulfonic acid possessed a weak (200) and (220) preferred orientation, respectively. Bright deposit obtained with thiourea only had (111)orientation, while the deposit obtained with mixture thiourea/disodium 2-naphthol-3,6-disulfonic acid exhibited predominant (111) orientation. Bright copper deposits had the preferred orientation in the closest-packed plane of f.c.c. copper lattice, i.e. in the (111)plane.
T2  - Materials Science Forum
T1  - The preferred orientation of bright copper deposits
VL  - 352
SP  - 73
EP  - 78
DO  - 10.4028/www.scientific.net/MSF.352.73
ER  - 

@article{
author = "Nikolic, ND and Stojilkovic, ER and Đurović, Dejan R. and Pavlović, Miomir G. and Knežević, VR",
year = "2000",
abstract = "The preferred orientations of copper deposits obtained from acid sulfate solutions were examined. Mat deposits obtained in the absence of the additives and in the presence of disodium 2-naphthol-3,6-disulfonic acid possessed a weak (200) and (220) preferred orientation, respectively. Bright deposit obtained with thiourea only had (111)orientation, while the deposit obtained with mixture thiourea/disodium 2-naphthol-3,6-disulfonic acid exhibited predominant (111) orientation. Bright copper deposits had the preferred orientation in the closest-packed plane of f.c.c. copper lattice, i.e. in the (111)plane.",
journal = "Materials Science Forum",
title = "The preferred orientation of bright copper deposits",
volume = "352",
pages = "73-78",
doi = "10.4028/www.scientific.net/MSF.352.73"
}

Nikolic, N., Stojilkovic, E., Đurović, D. R., Pavlović, M. G.,& Knežević, V.. (2000). The preferred orientation of bright copper deposits. in Materials Science Forum, 352, 73-78.
https://doi.org/10.4028/www.scientific.net/MSF.352.73

Nikolic N, Stojilkovic E, Đurović DR, Pavlović MG, Knežević V. The preferred orientation of bright copper deposits. in Materials Science Forum. 2000;352:73-78.
doi:10.4028/www.scientific.net/MSF.352.73 .

Nikolic, ND, Stojilkovic, ER, Đurović, Dejan R., Pavlović, Miomir G., Knežević, VR, "The preferred orientation of bright copper deposits" in Materials Science Forum, 352 (2000):73-78,
https://doi.org/10.4028/www.scientific.net/MSF.352.73 . .

TY  - JOUR
AU  - Premović, Pavle I.
AU  - Nikolic, ND
AU  - Tonsa, Ivana R.
AU  - Dulanovic, DT
AU  - Pavlović, Mirjana S.
PY  - 1999
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2255
AB  - High concentrations (up to 4000 ppm) of copper(rr) porphyrins have been detected in the kerogen of the Cretaceous/Tertiary (KT) boundary informal type sediment, the Fish Clay, at Stevns Klint, Denmark. These pigments have also been found in the Danish KT sediment at Nye Klov, which is about 300 kin away from Stevns Klint. However, copper(II) porphyrins cannot be detected in the Danich boundary rock of the Dania site, which is separated from Stevns Klint by about 200 kin. It is proposed that the kerogen copper(II) porphyrins are derived from humic materials of terrestrial (peat/soil) sources already enriched with these compounds, which were redeposited in the Danish KT boundary Basin. In addition, our results show that the kerogen copper(II) porphyrins are present, for comparison, in the Permian Kupferschiefer shale from Poland. The amounts are comparable to those in the Fish Clay kerogen. To our opinion, the same processes responsible for the kerogen copper(II) porphyrin enrichment have occurred in the Stevns Klint KT boundary sediment and in the Kupferschiefer.
T2  - Journal of the Serbian Chemical Society
T1  - Cretaceous-Tertiary boundary layer at Stevns Klint (Denmark): copper and copper(II) porphyrins
VL  - 64
IS  - 5-6
SP  - 349
EP  - 358
UR  - https://hdl.handle.net/21.15107/rcub_vinar_2255
ER  - 

@article{
author = "Premović, Pavle I. and Nikolic, ND and Tonsa, Ivana R. and Dulanovic, DT and Pavlović, Mirjana S.",
year = "1999",
abstract = "High concentrations (up to 4000 ppm) of copper(rr) porphyrins have been detected in the kerogen of the Cretaceous/Tertiary (KT) boundary informal type sediment, the Fish Clay, at Stevns Klint, Denmark. These pigments have also been found in the Danish KT sediment at Nye Klov, which is about 300 kin away from Stevns Klint. However, copper(II) porphyrins cannot be detected in the Danich boundary rock of the Dania site, which is separated from Stevns Klint by about 200 kin. It is proposed that the kerogen copper(II) porphyrins are derived from humic materials of terrestrial (peat/soil) sources already enriched with these compounds, which were redeposited in the Danish KT boundary Basin. In addition, our results show that the kerogen copper(II) porphyrins are present, for comparison, in the Permian Kupferschiefer shale from Poland. The amounts are comparable to those in the Fish Clay kerogen. To our opinion, the same processes responsible for the kerogen copper(II) porphyrin enrichment have occurred in the Stevns Klint KT boundary sediment and in the Kupferschiefer.",
journal = "Journal of the Serbian Chemical Society",
title = "Cretaceous-Tertiary boundary layer at Stevns Klint (Denmark): copper and copper(II) porphyrins",
volume = "64",
number = "5-6",
pages = "349-358",
url = "https://hdl.handle.net/21.15107/rcub_vinar_2255"
}

Premović, P. I., Nikolic, N., Tonsa, I. R., Dulanovic, D.,& Pavlović, M. S.. (1999). Cretaceous-Tertiary boundary layer at Stevns Klint (Denmark): copper and copper(II) porphyrins. in Journal of the Serbian Chemical Society, 64(5-6), 349-358.
https://hdl.handle.net/21.15107/rcub_vinar_2255

Premović PI, Nikolic N, Tonsa IR, Dulanovic D, Pavlović MS. Cretaceous-Tertiary boundary layer at Stevns Klint (Denmark): copper and copper(II) porphyrins. in Journal of the Serbian Chemical Society. 1999;64(5-6):349-358.
https://hdl.handle.net/21.15107/rcub_vinar_2255 .

Premović, Pavle I., Nikolic, ND, Tonsa, Ivana R., Dulanovic, DT, Pavlović, Mirjana S., "Cretaceous-Tertiary boundary layer at Stevns Klint (Denmark): copper and copper(II) porphyrins" in Journal of the Serbian Chemical Society, 64, no. 5-6 (1999):349-358,
https://hdl.handle.net/21.15107/rcub_vinar_2255 .

TY  - JOUR
AU  - Premović, Pavle I.
AU  - Allard, T
AU  - Nikolic, ND
AU  - Tonsa, Ivana R.
AU  - Pavlović, Mirjana S.
PY  - 1999
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2228
AB  - A new, rapid method for determining the concentration of vanadyl porphyrins (VO2+-P) associated with the kerogen of bituminous sedimentary rocks, using electron spin resonance (ESR) is described. The method is simple, straightforward and inexpensive. Several concentrations of a vanadyl (VO2+) standard dissolved in glycerol/lignite mixture were prepared. The VO2+ concentrations ranged from 100-1000 ppm. The anisotropic ESR spectra of both the standards and kerogen samples were recorded at room temperature and the integrated areas of the pre-selected ESR line (attributed to nuclear spin m(I) = -5/2) were computed. The concentrations of VO2+ found in the kerogen samples were calculated using the relative ratio of the integrated areas for the standards and the kerogen samples. The VO2+-P concentrations of the kerogen materials were then calculated using 450 as the mean molecular weight of these species. The quantitative determination of VO2+-P in the kerogen fractions in the range 800 ppm and 8000 ppm and higher is feasible by the method reported. The method of analysis was also extended to asphaltene samples (enriched with VO2+-P) and a coal sample containing associated with its organic fraction.
T2  - Journal of the Serbian Chemical Society
T1  - Vanadyl porphyrins in sedimentary kerogens/asphaltenes: Estimation of the concentration
VL  - 64
IS  - 2
SP  - 97
EP  - 108
UR  - https://hdl.handle.net/21.15107/rcub_vinar_2228
ER  - 

@article{
author = "Premović, Pavle I. and Allard, T and Nikolic, ND and Tonsa, Ivana R. and Pavlović, Mirjana S.",
year = "1999",
abstract = "A new, rapid method for determining the concentration of vanadyl porphyrins (VO2+-P) associated with the kerogen of bituminous sedimentary rocks, using electron spin resonance (ESR) is described. The method is simple, straightforward and inexpensive. Several concentrations of a vanadyl (VO2+) standard dissolved in glycerol/lignite mixture were prepared. The VO2+ concentrations ranged from 100-1000 ppm. The anisotropic ESR spectra of both the standards and kerogen samples were recorded at room temperature and the integrated areas of the pre-selected ESR line (attributed to nuclear spin m(I) = -5/2) were computed. The concentrations of VO2+ found in the kerogen samples were calculated using the relative ratio of the integrated areas for the standards and the kerogen samples. The VO2+-P concentrations of the kerogen materials were then calculated using 450 as the mean molecular weight of these species. The quantitative determination of VO2+-P in the kerogen fractions in the range 800 ppm and 8000 ppm and higher is feasible by the method reported. The method of analysis was also extended to asphaltene samples (enriched with VO2+-P) and a coal sample containing associated with its organic fraction.",
journal = "Journal of the Serbian Chemical Society",
title = "Vanadyl porphyrins in sedimentary kerogens/asphaltenes: Estimation of the concentration",
volume = "64",
number = "2",
pages = "97-108",
url = "https://hdl.handle.net/21.15107/rcub_vinar_2228"
}

Premović, P. I., Allard, T., Nikolic, N., Tonsa, I. R.,& Pavlović, M. S.. (1999). Vanadyl porphyrins in sedimentary kerogens/asphaltenes: Estimation of the concentration. in Journal of the Serbian Chemical Society, 64(2), 97-108.
https://hdl.handle.net/21.15107/rcub_vinar_2228

Premović PI, Allard T, Nikolic N, Tonsa IR, Pavlović MS. Vanadyl porphyrins in sedimentary kerogens/asphaltenes: Estimation of the concentration. in Journal of the Serbian Chemical Society. 1999;64(2):97-108.
https://hdl.handle.net/21.15107/rcub_vinar_2228 .

Premović, Pavle I., Allard, T, Nikolic, ND, Tonsa, Ivana R., Pavlović, Mirjana S., "Vanadyl porphyrins in sedimentary kerogens/asphaltenes: Estimation of the concentration" in Journal of the Serbian Chemical Society, 64, no. 2 (1999):97-108,
https://hdl.handle.net/21.15107/rcub_vinar_2228 .