Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Stojanović, B." wg kryterium: Autor

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-15 z 15
    Tytuł:
    Correlations of Mechanical Properties and Microstructure at Specific Zones of Welded Joint of High-Strength Low-Alloy Steels
    Autorzy:
    Ivanović, L.
    Marjanović, V.
    Ilić, A.
    Stojanović, B.
    Lazić, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/354032.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    high-strength low-alloy steel
    welded joint
    mechanical properties
    microstructure
    Opis:
    This paper presents experimental testing of the mechanical characteristics and properties of samples made of high-strength low-alloy steel with two different multi pass V grove butt welded joint. Two sample groups are tested: the root pass is made by manual metal arc welding process for the former and metal inert gas welding process for the latter. Other passes of those multi passes welded joints are made by metal active gas welding process. Further, the research included analyses of the experimentally obtained mechanical properties and load response of the samples in correlations to microhardness distribution and microstructural state at specific zones of the welded joints. Since both the chemical composition and microstructural state of high-strength low-alloy steel originate from special production processes their nature must be fully understood. Accordingly, the nature of the steels should directly impact not only the selection and definition of welding but the design process of mechanical constructions, too. From the practical aspect, mechanical characteristics and properties as well as load response of welded joints are crucial. But, sensitivity of those steels to inadequate welding technology and improper parameters or filler metal is high. On the other side, design codes and recommendations are not yet fully developed and precise. Results obtained in this research implicate that even small changes of welding technology causes the change of characteristics itself. Consequently, the steels development must be accompanied with the improvement of the welding processes and design modifications.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 1; 285-292
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    La-doped and La/Mn-co-doped Barium Titanate Ceramics
    Autorzy:
    Vijatović Petrović, M.
    Bobić, J.
    Grigalaitis, R.
    Stojanović, B.
    Banys, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1400499.pdf
    Data publikacji:
    2013-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.20.Ka
    81.40.Ef
    77.80.B-
    72.20.-i
    84.37.+q
    Opis:
    Barium titanate ceramics doped with 0.3 mol.% lanthanum and co-doped with 0.3 mol.% lanthanum and 0.05 mol.% manganese were investigated. The powders were prepared by a modified polymeric precursor method based on the Pechini process. The ceramics were obtained by sintering at 1300C for 8 h. The influence of dopants on structural changes and grain size reduction was analyzed. The presence of dopants influenced the tetragonality of the barium titanate crystal structure. Reduction of polygonal grain size with dopant addition was noticed. In the doped ceramics, characteristic phase transitions were shifted to lower temperatures in comparison with pure barium titanate. The dielectric permittivity value showed the tendency of a slight increase with lanthanum addition and further increase with adding of manganese. La as a single dopant increased the diffuseness of phase transitions indicating the formation of a diffuse ferroelectric material but in the co-doped ceramics the phase transition diffuseness decreased. The resistivity of the co-doped ceramics was higher than for lanthanum doped ceramics, indicating possible segregation of manganese at grain boundaries that influenced the total resistivity of the material.
    Źródło:
    Acta Physica Polonica A; 2013, 124, 1; 155-160
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of load and reinforcement content on selected tribological properties of Al/SiC/Gr hybrid composites
    Autorzy:
    Veličković, S.
    Miladinović, S.
    Stojanović, B.
    Nikolić, R. R.
    Hadzima, B.
    Arsić, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/111714.pdf
    Data publikacji:
    2018
    Wydawca:
    Stowarzyszenie Menedżerów Jakości i Produkcji
    Tematy:
    aluminum alloy
    hybrid composites
    silicon carbide
    graphite
    particles
    stop aluminium
    węglik krzemu
    grafit
    kompozyty hybrydowe
    Opis:
    Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.
    Źródło:
    Production Engineering Archives; 2018, 18; 18-23
    2353-5156
    2353-7779
    Pojawia się w:
    Production Engineering Archives
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Characterization of Barium Titanate Ceramic Powders by Raman Spectroscopy
    Autorzy:
    Lazarević, Z.
    Romčević, N.
    Vijatović, M.
    Paunović, N.
    Romčević, M.
    Stojanović, B.
    Dohčević-Mitrović, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/1808060.pdf
    Data publikacji:
    2009-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    77.84.-s
    81.07.Bc
    81.20.Ev
    83.85.Hf
    Opis:
    Barium titanate, $BaTiO_3$ ceramic powders were prepared by mechanochemical synthesis and by the Pechini method. A powder mixture of BaO and $TiO_2$ was treated in a planetary ball mill in an air atmosphere for up to 1 h, using zirconium oxide vial and zirconium oxide balls as the milling medium. After 60 min $BaTiO_3$ phase was formed. In both ways $BaTiO_3$ ceramics were sintered after 2 h on 1300°C without pre-calcinations step. The heating rate was 10°C $\text{min}^{-1}$. The formation of phase and crystal structure of $BaTiO_3$ was approved by X-ray diffraction analysis and the Raman spectroscopy. The morphology and microstructure of obtained powders were examined by scanning electron microscopy method. Sharp phase transition from ferroelectric to paraelectric state was observed. The hysteresis loop is very well performed with regular sharp characteristic of ferroelectric materials.
    Źródło:
    Acta Physica Polonica A; 2009, 115, 4; 808-810
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Finite-time stability and stabilization of singular state-delay systems using improved estimation of a lower bound on a Lyapunov-like functional
    Autorzy:
    Stojanovic, S. B.
    Debeljkovic, D. Lj.
    Antic, D. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/200145.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    singular systems
    time-delay
    LMIs
    finite-time stability
    stabilizing controllers
    cone complementarity
    linearization
    cone complementarity linearization algorithm
    systemy pojedyńcze
    czas opóźnienia
    stabilność w czasie skończonym
    kontrolery stabilizujące
    komplementarność
    linearyzacja
    algorytm cone complementarity linearization
    Opis:
    In this paper, the problems of finite-time stability and stabilization for a class of singular time-delay systems are studied. Using the Lyapunov-like functional (LLF) with (exponential or power) weighting function and a new estimation method for the lower bound on LLF, some sufficient stability conditions are introduced. It is shown that the weighting function significantly reduces the conservatism of the stability criteria in comparison to estimation of the lower bound on LLF without this function. To solve the finite-time stabilization problem, a stabilizing linear state controller is designed by exploiting the cone complementarity linearization algorithm. Two numerical examples are given to illustrate the effectiveness of the proposed method.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 2; 479-487
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Growth response of different tree species (oaks, beech and pine) from SE Europe to precipitation over time
    Autorzy:
    Stojanović, Dejan B.
    Levanič, Tom
    Matović, Bratislav
    Stjepanović, Stefan
    Orlović, Saša
    Powiązania:
    https://bibliotekanauki.pl/articles/956967.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Instytut Dendrologii PAN
    Tematy:
    standardized precipitation index (spi)
    climate change
    tree mortality
    quercus sp.
    fagus sylvatica
    pinus sylvestris
    Opis:
    Changing climatic conditions can have various consequences for forest ecosystems, from increasing frequencies of forest fires, ice and windstorm events to pathogen outbreaks and mass mortalities. The Standardized Precipitation Index (SPI) was chosen for the evaluation of drought impact on the radial growth of trees after extensive preliminary testing of various calculated monthly climate parameters from the CARPATCLIM database. SPI was calculated for periods between 3 and 36 months for different sites (lowland and mountainous parts of Serbia, Southeast Europe), from which Quercus robur, Q. cerris, Fagus sylvatica and Pinus sylvestris samples were acquired. Bootstrapped Pearson’s correlations between SPI monthly indices and radial growth of tree species were calculated. We found that 12-month SPI for summer months may be a good predictor of positive and negative growth of different species at different sites. The strongest positive correlations for five of six tree-ring width chronologies were between 12-month June and 14-month September SPI, which implies that high growth rates can be expected when the autumn of the previous year, and winter, spring and summer of the current year, are well supplied with precipitation, and vice versa (low precipitation in given period/low growth rates).
    Źródło:
    Dendrobiology; 2018, 79; 97-110
    1641-1307
    Pojawia się w:
    Dendrobiology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of postpartum administration of ketoprofen on proinflammatory cytokine concentration and their correlation with lipogenesis and ketogenesis in Holstein dairy cows
    Autorzy:
    Kovacevic, Z.
    Stojanovic, D.
    Cincovic, M.
    Belic, B.
    Davidov, I.
    Stojanac, N.
    Galfi, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2087477.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    ketoprofen
    TNF-α
    IL-1α
    IFN-γ
    cow
    Źródło:
    Polish Journal of Veterinary Sciences; 2019, 3; 609-615
    1505-1773
    Pojawia się w:
    Polish Journal of Veterinary Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Association of metabolic and inflammatory markers with milk yield in postpartum dairy cows treated with ketoprofen
    Autorzy:
    Kovacevic, Z.
    Stojanovic, D.
    Cincovic, M.
    Belic, B.
    Davidov, I.
    Plavsa, N.
    Radinovic, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2087713.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    ketoprofen
    TNF-a
    haptoglobin
    NEFA
    BHB
    cow
    milk yield
    Źródło:
    Polish Journal of Veterinary Sciences; 2018, 21, 2; 325-331
    1505-1773
    Pojawia się w:
    Polish Journal of Veterinary Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Resonant Raman Spectra of CdTe/ZnTe Self Assembled Quantum Dots
    Autorzy:
    Romčević, N.
    Romčević, M.
    Kostić, R.
    Stojanović, D.
    Abolmasov, B.
    Karczewski, G.
    Galazka, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1807840.pdf
    Data publikacji:
    2009-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    63.22.-m
    78.30.Fs
    78.55.Et
    Opis:
    In this paper we present Raman scattering and photoluminescence spectra measured on CdTe/ZnTe self assembled quantum dots. The photoluminescence spectrum has shown two main emission peaks, both connected with existing of quantum dots. One presents direct deexcitation to ground state and the other is optical phonon (οmega = 207.3 $cm^{-1}$)-assisted deexcitation. The registered multiphonon emission process depends on temperature. At low temperature phonon spectra shows line at 450 $cm^{-1}$ (TA + 2LO in ZnTe) and 595 $cm^{-1}$ (2LO + TO(Γ) in ZnTe).
    Źródło:
    Acta Physica Polonica A; 2009, 116, 1; 88-90
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Surface characterization of the raw and cooked bovine cortical metatarsal bone
    Autorzy:
    Petrovic, Bojan B.
    Kojic, Sanja
    Peric, Tamara O.
    Šipovac, Milica
    Lazarevic, Jovana
    Stefanovic, Sofija
    Stojanovic, Goran
    Powiązania:
    https://bibliotekanauki.pl/articles/306722.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    kości
    właściwości elastyczne
    SEM
    nanoindentacja
    bone
    elastic properties
    direct temperature exposure
    nanoindentation
    Opis:
    The purpose of this study was to quantify the elastic properties and evaluate microscopical features of raw and boiled metatarsal bovine bone. Methods: The elastic modulus, hardness and microscopic surface of raw and cooked bovine metatarsal bone have been investigated using nanoindentation, SEM/EDX and Panasis microscope. Results: Regarding raw bovine bone, the average elastic modulus was 30.515 ± 6,769 GPa, while the average hardness was 0.5683 ± 0.211 GPa. When it comes to boiled bone corresponding values were 22.298 ± 7.0303 GPa and 0.408 ± 0.199 GPa, respectively. The values for investigated parameters were significantly higher ( p < 0.05) in raw bone specimens. Elastic modulus significantly correlated with hardness ( p < 0.05). EDX analysis revealed significant decrease in wt% of oxygen in boiled samples ( p < 0.05) No significant differences could be observed in SEM images particularly when analysing in smaller magnifications. Using higher magnification, additional branching of the existing voids as well as discrete reorganization and smoother edges of nutrient canals could be observed. The surface of boiled specimens was without the presence of crusts and layering, and no microscopical evidence of structural damage could be observed. Conclusions: This study provides detailed analysis of hardness, elastic modulus of raw and cooked bovine bone and their relation and changes during exposure to temperature. These results of elastic moduli and hardness could be comparable to similar studies of bovine and human bone tissue, but the careful analysis of experimental design, type of the bone as well as limitations of the employed techniques must be carried out before interpolation of the results to other theoretical, clinical, biomaterial and archeological studies.
    Źródło:
    Acta of Bioengineering and Biomechanics; 2019, 21, 1; 13-21
    1509-409X
    2450-6303
    Pojawia się w:
    Acta of Bioengineering and Biomechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Off label use of human approved drugs in treatment of dogs in the Republic of Serbia
    Autorzy:
    Tomanic, D.
    Stojanovic, D.
    Belić, B.
    Davidov, I.
    Novakov, N.
    Radinovic, M.
    Kladar, N.
    Kovacevic, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/2087106.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    off label use
    human drugs
    dogs
    cascade procedure
    antimicrobials
    Źródło:
    Polish Journal of Veterinary Sciences; 2021, 24, 3; 399-407
    1505-1773
    Pojawia się w:
    Polish Journal of Veterinary Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Far-Infrared Study of DX-Like Centers in Pb$\text{}_{0.95}$Mn$\text{}_{0.05}$Te(Ga)
    Autorzy:
    Stojanović, D.
    Trajić, J.
    Hadžić, B.
    Romčević, M.
    Ivanchik, I. I.
    Khokhlov, D. R.
    Romčević, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/2047857.pdf
    Data publikacji:
    2007-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.28.+d
    78.20.-e
    63.20.Pw
    Opis:
    We present far-infrared reflection spectra of Pb$\text{}_{0.95}$Mn$\text{}_{0.05}$Te single crystal doped with gallium between 10 and 300 K. The analysis of the far-infrared reflection spectra was made by a fitting procedure based on the model of coupled oscillators. Together with the strong plasmon-phonon coupling we obtain three local modes of gallium at about 122 cm$\text{}^{-1}$, 166 cm$\text{}^{-1}$, and 192 cm$\text{}^{-1}$. The position of these modes depends on impurity center charge, and their intensity depends on temperature.
    Źródło:
    Acta Physica Polonica A; 2007, 112, 5; 959-962
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Potentiality of obtaining mica flotation concentrate from kaolinised granite
    Badanie możliwości otrzymywania koncentratu poflotacyjnego zawierającego mikę ze skaolinizowanego granitu
    Autorzy:
    Sekulić, Živko
    Mihajlović, Slavica R.
    Stojanović, Jovica N.
    Ivoševic, Branislav B.
    Kašić, Vladan D.
    Ignjatović, Miroslav R.
    Powiązania:
    https://bibliotekanauki.pl/articles/218923.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    skaolinizowany granit
    muskowit
    biotyt
    koncentrat w procesie flotacji
    koncentrat zawierający mikę
    kaolinised granite
    muscovite
    biotite
    flotation concentration
    mica concentrate
    Opis:
    This study shows the results of flotation concentration of mica minerals from kaolinised granite taken from the "Bašića bare" deposit – Kobaš, Srbac, The Republic of Srpska (B&H). Mineralogical composition of kaolinised granite is as follows: kaolinite, feldspar, quartz, and mica. After separating >0.630 mm, and <0.043 mm size class where kaolinite is concentrated, the rest is –0.630+0.043 mm class containing quartz, feldspar and mica. The mica concentrate was obtained by the flotation concentration, while feldspar and quartz were in the flotation underflow. According to the mineralogical analysis, the most abundant minerals are mica and chlorite/clays, while quartz and feldspar occur much less, and accessory minerals are represented in trace. The semi-quantitative mineralogical analysis obtained by the X-ray powder diffraction (XRPD) method of the mica concentrate amount to: mica ≈55%, chlorite/clays ≈35%, quartz ≈5%, feldspars (plagioclase and K-feldspars combined) ≈5%.
    W pracy omówiono wyniki badania koncentratu poflotacyjnego zawierającego minerały z grupy miki ze skaolinizowanego granitu pozyskiwanego ze złoża Basica bare w Kobas, w Republice Serbskiej (B&H). Skaolinizowany granit zawiera następujące minerały: kaolinit, skaleń, kwarc i mika. Po wyodrębnieniu klas ziaren o wymiarach >0.630 mm i <0.043 mm, zawierających największe ilości kaolinitu, pozostały produkt stanowi klasa ziaren o wymiarach –0.630+0.043, zawierających kwarc, skaleń oraz mikę. Koncentrat zawierający mikę otrzymano z koncentratu poflotacyjnego, skaleń i kwarc zebrano w produkcie dolnym procesu flotacji. W oparciu o analizy składu mineralogicznego stwierdzono, że minerałami występującymi w największych ilościach są mika oraz chloryty/iły, kwarc oraz skalenie wy-stępują w znacznie mniejszych ilościach podczas gdy pozostałe minerały występują jedynie w ilościach śladowych. Przeprowadzona analiza mineralogiczna koncentratu miki w ujęciu ilościowym w oparciu o wyniki rentgenowskiej dyfraktometrii proszkowej (X-ray powder diffraction – XRPD) ujawniła że skład jego jest następujący: mika ≈55%; chloryty/iły ≈35 %; kwarc ≈5%; skalenie (łącznie plagioklazy i skalenie potasowe) ≈5%.
    Źródło:
    Archives of Mining Sciences; 2019, 64, 3; 499-508
    0860-7001
    Pojawia się w:
    Archives of Mining Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Raman Spectroscopy of Multiphonon Emission Process in Ni-Doped PbTe
    Autorzy:
    Romčević, N.
    Trajić, J.
    Hadžić, B.
    Romčević, M.
    Stojanović, D.
    Lazarević, Z.
    Kuznetsova, T.
    Khokhlov, D.
    Rudolf, R.
    Anžel, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/1807841.pdf
    Data publikacji:
    2009-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.28.+d
    63.20.-e
    78.30.-j
    Opis:
    In this paper, we present room temperature unpolarized Raman scattering spectra of Ni doped PbTe single crystal sample. Crystal of PbTe(Ni) was grown by the Bridgman method. The Ni concentration in the sample used here was 1× $10^{19}$ at./$cm^{3}$. Well resolved peaks appear at about 126, 143, 181, 362 and 724 $cm^{-1}$. The modes at 126 and 143 $cm^{-1}$, which are also observed in other telluride compounds, originate from vibrations in $TeO_2$. We assume that the mode at about 181 $cm^{-1}$ is connected to excitations of a local phonon mode in the vicinity of an impurity atom (donor $Ni^{3+}$ state). Modes at about 362 $cm^{-1}$ and 724 $cm^{-1}$ are the second and fourth harmonic of a local phonon mode, registered here due to multiphonon emission.
    Źródło:
    Acta Physica Polonica A; 2009, 116, 1; 91-92
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Organic geochemical study of the Lower Miocene Kremna Basin, Serbia
    Autorzy:
    Perunović, T.
    Stojanović, K.
    Simić, V.
    Kašanin-Grubin, M.
    Šajnović, A.
    Erić, V.
    Schwarzbauer, J.
    Vasić, N.
    Jovančićević, B.
    Brčeski, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/191854.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    Kremna Basin
    lacustrine sediments
    organic matter
    mineralogy
    biomarkers
    pyrolysis
    Opis:
    The Kremna Basin is located in southwest Serbia, in the Zlatibor area, which is part of the Internal Dinarides. This basin is noteworthy because of the type of bedrock drainage, which it represents. It was formed on ultrabasic rocks and volcanic materials that influenced the occurrence of organic matter (OM) in the basin fill. The objective of the study was to determine the organic geochemical characteristics of sediments from the central part of the Kremna Basin. The sediments studied belong to an intrabasinal facies, in which two sequences were distinguished. The lower sequence occurs at depths of 216–343 m, while the upper sequence is found from 13.5–216 m. At the start of basin development (265–343 m) sedimentation took place in shallow alkaline water, rich in Mg ions. Through time, a slight deepening of the basin occurred. This was followed by chemical deposition of carbonates (216–265 m). The most important change in the sedimentary environment occurred with the formation of sediments marking the transition between the sequences (at about 200 m). Sediments from the lower sequence are characterized by the dominance of dolomite and magnesite. There are indications of volcanic activity, i.e. tuff layers and the presence of searlesite. The upper sequence is characterized by the prevalence of calcite and dolomite. The amounts of MgO, Na2O and B are higher in the lower sequence, whereas the CaO content is higher in the upper sequence. The sediments contain different amounts of immature OM (late diagenesis). Biomarker analysis shows diverse precursors of the sedimentary OM: methanogenic archaea, photosynthetic green sulfur bacteria (Chlorobiaceae), bacterivorous ciliates, various bacteria, both photosynthetic and non-photosynthetic, the green unicellular microalga, Botryococcus braunii race A (exclusively in the upper sequence) and terrestrial plants. The lower sequence contains lower amount OM, composed primarily of kerogen II/III and III types, indicating a higher contribution of the allochtonous biomass of land plants from the lake catchment, particularly in the lower part. The sediments of the upper sequence are enriched in autochthonous aquatic OM, which comprises mostly kerogen I, I/II and II types. The transition from the lower sequence to the upper one is associated with a decrease in pristane to phytane ratio, gammacerane index and content of C28 steroids, absence or significantly lower amount of squalane, absence of C24 and C25 regular isoprenoids, 8-methyl-2-methyl-2-(4,8,12-trimethyltridecyl) chroman and C30 hop-17(21)-ene. Pyrolytic experiments showed that the sediments of the upper sequence, rich in aquatic OM, at a catagenetic stage could be a source of liquid hydrocarbons. The values of hopane, sterane and phenanthrene maturation parameters indicate that through pyrolysis at 400°C the samples investigated reached a value of vitrinite reflectance equivalent of approximately 0.70%. It was estimated that the sediments should be found at depths of 2300–2900 m in order to become active source rocks. The calculated minimum temperature, necessary for catagenetic hydrocarbon generation, is between 103 and 107°C.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2014, 84, 3; 185-212
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-15 z 15

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies