Vladimír Machovič

Academy of Sciences of the Czech Republic, Praha, Praha, Czech Republic

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Publications (59)81.2 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: High pressure sorption experiments with carbon dioxide and methane were carried out at a temperature of 45 °C and at pressures up to 15 MPa with three samples of methane-bearing, medium-rank coals in a moisture-equilibrated state using a manometric method. The samples were taken from selected positions of drill cores from exploration boreholes in the Bohemian part of the Upper Silesian Basin, and were characterized by a narrow range of degree of coalification and markedly different petrographic compositions, including a different mineral matter content. The total porosity of the coal samples was between 9% and 10%. A positive correlation was found between the equilibrium moisture in the coal samples and the total abundance of oxygen functional groups determined by FTIR. The excess sorption capacities ranged from 0.78 to 0.91 mmol g−1 for CO2 and from 0.45 to 0.52 mmol g−1 for CH4, and after recalculation to coal organic matter, the excess sorption capacities increased by up to 14% in the coal with the highest mineral fraction. The highest CO2/CH4 ratio was found in the sample that had the highest inertinite and liptinite content. The experimental isotherm data was fitted by modified Langmuir and Dubinin–Radushkevich sorption isotherms. The parameters obtained by these two methods were in good agreement for carbon dioxide. It was found that the sorption capacity of the organic matter in a coal sample with prevalence of inertinite (63.0 vol.%) was lower only by 14% for CO2 and by 18% for CH4 than the sorption capacity of the organic matter in a coal sample with prevalence of vitrinite (65.3 vol.%). This provided confirmation that the petrographic composition of a coal has an ambiguous effect.
    Fuel 01/2015; 139:115–124. · 3.36 Impact Factor
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    ABSTRACT: The interaction of toxic oxyanions with organic matter can affect their stability and binding mechanisms in soils. The adsorption/desorption properties of arsenic (AsV)/antimony (SbV) oxyanions were tested with two types of soil with a variable content of natural organic matter (NOM). Sample JEZ (I) represented a locality near a brown-coal power plant, and therefore formerly exposed to large amounts of atmospheric pollution, while sample LIZ (II) originated in an uncontaminated region without anthropogenic impact. Soil samples were investigated from the organic O and mineral B horizons. Different As/Sb fixations were indicated by their different adsorption affinity to O and B horizons. Arsenic as AsV was strongly adsorbed in B horizons, while antimony as SbV was predominantly bound in O horizons. The sorption followed the Langmuir model with maximum adsorption capacities of 1.4 × 10−2 mmol g−1 for As and 1.0 × 10−2 mmol g−1 for Sb adsorptions. The release of As and Sb to distilled water and 0.1 m KCl illustrated the significantly larger stability of As and Sb oxyanions in ionic solutions, where available ions prevented the aggregation of organic matter, thus maintaining the balanced distribution of surface charge. Distilled water with a pH of about 6 supported a negative surface charge density and enhanced the release of As/Sb oxyanions.
    European Journal of Soil Science 12/2014; · 2.65 Impact Factor
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    ABSTRACT: A few non-conventional humate sorbents, i.e. iron humate (FeH), aluminium humate (AlH), calcium humate (CaH), magnesium humate (MgH), and zinc humate (ZnH), were prepared from a commercial product Fortehum L/K (Humatex, Bílina, Czech Republic). The metal content in humates was determined by X-ray fluorescence analysis, the organic elements (C, H, N, and S) were analysed by an Elementar Vario III and the functional groups were determined by classical methods using KBr pellets and diffuse reflection infrared spectroscopy (DRIFTS). FeH, AlH, and ZnH were tested as sorbents for the removal of inorganic or organic pollutants (metals, inorganic ions, dyes, and chlorophenols) from waste water. Sorption properties decreased in order: ZnH, AlH, FeH. CaH and MgH are partly soluble and therefore they are not usable as sorbents. However, their ion-exchange abilities for heavy metals are excellent which makes them usable for phytoremediation and bioremediation.
    Chemical Papers- Slovak Academy of Sciences 11/2014; 68(11). · 0.88 Impact Factor
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    ABSTRACT: Contents of uranium in coals from Odeř in the northernmost part of the Sokolov Basin, Czech Republic, in the vicinity of the well known St. Joachimsthal uranium ore deposits, reach extremely high values. In the present work, coal samples with contents of uranium ranging from 0.02 to 6 wt.% were studied. The study employing a whole complex of analytical techniques has been aimed at identification of changes in the structure of coal organic matter, which are associated with the high contents of uranium in coal. The study includes proximate and ultimate analyses, multielement analysis by instrumental neutron and photon activation analyses, micropetrographic analysis by optical microscopy, ESEM/EDX analysis of mineral matter, infrared and Raman spectroscopies, solvent extraction followed by gas chromatography with mass spectroscopy (GC/MS), and analytical pyrolysis (Py-GC/MS). The study has confirmed previously proposed explanation of uraniferous mineralization in sedimentary carboniferous substances by the mechanism of reduction and fixation of soluble U(VI) (uranyl, UO2(2+)) species (e.g., humic, carbonate/hydroxo/phosphate complexes) by sedimentary organic matter under diagenetic or hydrothermal conditions, and formation of insoluble U(IV) species as phosphate minerals and uraninite. The process is accompanied with alteration and destruction of the coal organic matter. The changes in the structure of coal organic matter involve dehydrogenation and oxidation mainly in the aliphatic, aromatic and hydroxyl structures, and an increase in aromaticity, content of ether bonds, and the degree of coalification.
    Journal of environmental radioactivity. 07/2014; 137C:52-63.
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    ABSTRACT: The base sand layers of the aeolian Great Dune of Pilat, which stretches along the coast of Arcachon Bay, have been locally impregnated with a dark brown to black amorphous organic substance of humate composition. The humate-cemented sand forms a well-indurated horizon 40–50 cm in thickness that developed immediately beneath the Holocene peaty layer (P1“paleosoil”). The humate, identified by means of FT-IR and Raman micro-spectroscopy, acted both as a cementing agent and as a coloring agent; it formed thin coats and meniscus cements between individual sandstone grains which, in turn, caused the dark, asphaltic-like appearance of the sandstone. Field observations, combined with geochemical analyses, and the presence of identical geochemical compounds recognized in the peat and sandstone humate cement, suggest that the peat-containing low-coalified (Rr = 0.2%) fragments of higher, submerged and floating plants and marine algae deposited in a saline and reducing environment served as an obvious source rock for the humate. The humate derived from decaying organic remains that descended from the peat into the permeable sand, where it indurated irreversibly over a period shorter than 3500 years.The present-day actions of waves and tides contribute to the erosion of the frontal parts of the humate-impregnated sandstone horizon, resulting in the formation of the dark rounded sandstone slabs and pebbles that are deposited on nearby beaches. This process provides a fine example of recent black pebble formation that derived from pre-existing organic matter-impregnated source rocks. In contrast to their tropical carbonate counterparts, however, the humate-induced blackening of the sandstone pebbles appears to be relatively unstable, as the impregnated fragments bleach when exposed to air and seawater for a few seasons.
    International Journal of Coal Geology 07/2013; 114:19–32. · 3.31 Impact Factor
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    ABSTRACT: In this article, we report on the optical properties of Bismuth doped Epoxy Novolak Resin (ENR) co‐doped with Dysprosium, Cerium, and Yttrium ions. The polymer layers containing 1.0 to 20.0 at % of Bismuth were fabricated by spin‐coating onto silicon or quartz substrates. The properties of the material were studied using several methods with special regards to its potential utilization in photonics devices. Transmission spectra were taken in the range from 350 to 1600 nm, while photoluminescence spectra around 1300 nm were recorded by using excitation of semiconductor lasers operating at 808 nm and at 980 nm (E x = 250 mW). Optical properties of the samples were evaluated on the bases of the concentration of the Bismuth ions as well as on the concentrations of the co‐doping ions and showed close relations between concentration of the dopants and intensity of the luminescence band at 1300 nm. Our results proved that the Bismuth doped ENR has a strong potential for application in active photonics structures, as it has excellent optical properties and very easy and not demanding fabrication procedures. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
    Journal of Applied Polymer Science 07/2012; 125(1). · 1.40 Impact Factor
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    ABSTRACT: Ni2Si, NiSi and NiSi2 contacts were prepared on n-type 4H– and 6H–SiC(0001) by deposition of Ni and Si multilayers in the respective stoichiometry after high-temperature annealing, as well as pure Ni contacts. After annealing, the individual contacts were analyzed by Raman spectroscopy and electrical property measurements. Contact structures were then etched-off and subsequently observed by means of AFM (Atomic Force Microscopy). Ni reacted with SiC, forming Ni2Si and carbon. At NixSiy/SiC contact structures the respective silicides were already formed at low annealing temperatures, when only Schottky behavior of the structures was observed. The intended silicides, once formed, did not change any further with increasing annealing temperature. All contact structures provided good ohmic behavior after being annealed at 960 °C. By means of combined AFM and Raman analysis of the etched-off contacts we found that the silicide contact structures very probably did not react with SiC which is in accordance with the thermodynamic assumptions. After annealing the silicide contact structures at such temperature, when Schottky behavior changed to ohmic, a certain form of interaction between the SiC substrate and the silicide contact structures must have occurred.
    Thin Solid Films 04/2012; 520(13):4378–4388. · 1.87 Impact Factor
  • M. Lhotka, V. Machovič, B. Doušová
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    ABSTRACT: The use of clay materials as selective sorbents for different contaminants requires very efficient methods. A natural kaolinite was calcined to metakaolinite and than rehydrated at different temperatures to produce a highly porous sorbent. The kinetics of this process were measured, with subsequent IR characterization of the phases formed. The surface and pore distribution of new phases were also assigned. In addition, the kaolinite obtained was pre-treated with Fe3+ ions to improve its sorption affinity for anionic particles. The rehydrated kaolinite and its Fe-modification were used for the adsorption of toxic cations (Zn, Cd, Pb) and anions (As, Se). Adsorption capacities depending on the physical chemical properties of the initial solution (pH, concentration of toxic ions) and the surface properties of the sorbent (specific surface area, modification method) were investigated. The adsorption properties of the sorbents were defined by the Langmuir model.
    Clay Minerals 01/2012; 47(2). · 1.07 Impact Factor
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    ABSTRACT: The use of clays as effective arsenic sorbents has been strongly limited due to their low pHZPC and cation active behaviour in aqueous systems at pH>3.5. A simple Fe/Al/Mn pre-treatment can significantly improve their sorption affinity to oxyanions, including arsenites and arsenates. The dynamics of arsenic adsorption from groundwater is also controlled by dissolved Fe/Mn ions, which behave as promoters of As adsorption, or competitors to adsorption sites. Low grade calcinated kaolin (MT) and bentonite (BT) were used as clay sorbents. Arsenic adsorption on raw clays without presence of Fe/Mn ions is very slow and limited. During co-adsorption the Fe/Mn ions and As oxyanions were adsorbed together onto a sorbent surface. Both Mn and Fe particles demonstrated a good sorption affinity to the clay surface, but only Fe particles supported As adsorption considerably (80% of As were removed in Fe/As system, while
    Applied Clay Science - APPL CLAY SCI. 01/2011; 54(2):166-171.
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    ABSTRACT: Ni, Ni2Si and Pd contacts were prepared on n-type 4H-SiC and annealed in the temperature range of 750–1150 °C. The annealed contacts were analyzed before and after acid etching, and different features were found in unetched and etched contacts. Carbon left on the SiC surface after the acid etching of Ni2Si contacts annealed at 960 °C was highly graphitized. In nickel contacts, the graphitization of interface carbon began at 960 °C and increased after annealing at higher temperatures. In palladium contacts, the onset of the interface carbon graphitization was observed after annealing at 1150 °C. For all three types of metallization, the minimal values of contact resistivity were achieved only when the sharp first-order peak at 1585 cm−1 and distinct second-order peak at ∼2700 cm−1 related to the presence of graphitized carbon were detected by Raman spectroscopy after the acid etching of contacts. The properties of unannealed secondary contacts deposited onto etched primary contacts were similar to the properties of the primary contacts unless carbon was selectively etched. The results show that ohmic behavior of Ni-based and Pd contacts on n-type SiC originates from the formation of graphitic carbon at the interface with SiC.
    Applied Surface Science 11/2010; 257(2):414–422. · 2.54 Impact Factor
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    ABSTRACT: A study of the ion implantation of Cu+, Ag+ or Au+ ions into different types of silicate glasses is reported. The energy of the implanted ions was 330 keV and the implantation fluence was kept at 1 × 1016 cm− 2. The samples were characterised by various analytical methods: Rutherford backscattering spectrometry for the concentration depth profiles of the implanted atoms, Raman spectroscopy for the structure of the samples and also by UV–VIS absorption spectroscopy. The obtained data were evaluated on the bases of the structure of the glass matrix and the relations between the structural changes and optical properties, important for photonics applications, were formulated.The main focus was the impact of various types and concentrations of glass network modifiers (e.g. Li, Na, K, Mg, Ca or Zn) as well as glass network formers (Si, and B) on the projected range of the implanted ions. Interesting results were also provided by a study of the annealing of the as-implanted samples in various types of glass substrates. The study showed that each of the implanted ions migrated in the substrates with different glass structures via unique mechanisms.
    Journal of Non-Crystalline Solids 10/2010; · 1.72 Impact Factor
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    ABSTRACT: In this article, we report on the optical properties of bismuth ions doped epoxy novolak resin (ENR). The polymer layers containing 1–20 at. % of bismuth were fabricated by spin coating onto silicon or quartz substrates. The properties of the material were studied using several methods with special regards to its potential utilization in photonics devices. Absorption spectra were taken in the range from 350 to 800 nm. Optical band gap Eg was determined from the absorption coefficient values using Tauc's procedure, i.e., from the relationship αhv = A(hv − Eg)2 and the obtained values varied from 2.94 to 3.23 eV depending on the amount of bismuth ions involved in the samples. Photoluminescence spectra around 1300 nm were recorded by using excitation of semiconductor lasers operating at 808 nm (Ex = 500 mW). Optical properties of bismuth-doped ENR were evaluated on the bases of the concentration of the bismuth ions involved in the samples and showed, e.g., close relations between concentration of the dopants and intensity of the luminescence band at 1300 nm. IR spectra showed only negligible changes in the original substrate resin. Our results proved that the bismuth-doped ENR have a potential for utilization in photonic devices. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
    Journal of Applied Polymer Science 03/2010; 117(3):1608 - 1612. · 1.40 Impact Factor
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    ABSTRACT: The petroleum charge history of the Barrandian basin was investigated by analysing quartz and calcite and organic phases that occur in veins and fractures cutting dolerite sills within the Liteň Formation (Silurian). The geochemical characteristics of fluid inclusions trapped in vein quartz and calcite, vein bitumens and adjacent potential source rocks when combined with burial and thermal history data reflect the presence of at least three separate hydrocarbon charge episodes. Solid highly reflecting (Rmax = 0.92–1.49%) bitumen provides information on the first and oldest episode of oil migration. The precursor oil was probably derived relatively early during diagenesis from nearby organic-rich sediments and was subsequently thermally altered to form the solid bitumen.The liquid oil preserved within the fluid inclusions in vein quartz and calcite cements represents a second hydrocarbon charge that migrated after the cooling of the sill, at diagenetic temperatures between 73 and 150 °C. This migration event probably occurred during the peak burial of the strata, during or after the Variscan orogeny. The inclusion oil is moderately matured, non-biodegraded and most likely derived from lower Palaeozoic source rocks such as the enclosing Liteň formation and/or directly overlying Kopanina and Přídolí formations. The presence of low salinity (0.2–3.2 eq. wt. % NaCl) aqueous inclusions coexisting with oil inclusions, indicates that the hydrocarbon flow had a substantial aqueous component.Brightly yellow-fluorescing, low-reflecting (Rr = 0.25 %) wax forming thin coatings on vein minerals herald the third and most recent pulse of hydrocarbons that migrated significantly after the peak heating of the strata. Indirect evidence suggests that this late-stage event may have been associated with the post-Palaeogene Alpine uplift of the basin that stimulated circulation of waxy oils and acid waters through the reactivated fractures.
    Marine and Petroleum Geology. 01/2010;
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    ABSTRACT: In this paper, we demonstrate that combined application of X-ray diffraction (XRD), electron microscope/microprobe analysis (EMPA), and Raman microspectroscopy is an available and powerful approach for identification and characterization of iron arsenate minerals in complex environmental samples. Arsenic-rich material from the medieval mining dump close to the Giftkies mine in the Jáchymov ore district (Czech Republic) has been studied. Scorodite, kankite, amorphous iron arsenate (pitticite), and, to a lesser extent, native sulfur were determined in the studied samples as products of low-temperature arsenopyrite weathering. Scorodite and kankite form mixed nodules and crusts, which are locally coated by hardened gel-like amorphous pitticite. Pitticite also borders fractures in the mineralized rock fragments in the dump. Native sulfur, in microscopic crystals and grainy aggregates, originates directly in places with dissolved arsenopyrite and forms pseudomorphs. The Raman spectra presented in the paper can serve as comparative data for phase identification in other contaminated areas. New Raman data for the hydroxyl stretching region of scorodite (important bands: 3514, 3427, and 3600 cm(-1)) and the whole Raman spectrum for pitticite (important bands: 472, 831, 884, 2935, 3091, 3213, 3400, and 3533 cm(-1)) are a valuable output of this paper.
    Applied Spectroscopy 07/2009; 63(6):621-6. · 1.94 Impact Factor
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    ABSTRACT: In this article, we report the fabrication and optical/spectroscopic properties of polymethylmethacrylate (PMMA) doped with rare earth (RE) (Er3+ and Er3+/Yb3+) ions. Infrared spectroscopy revealed only very weak OH stretching vibration peaks in the samples, which is important if satisfactory photoluminescence is to be observed at 1530 nm. Measurement of transmission spectra in the wavelength ranges from 300 to 700 nm for Er3+-doped samples and from 900 to 1050 nm for Yb3+-doped samples enabled us to observe the 4G11/2 (377 nm) and 2H11/2 (519 nm) transmission bands typical for Er3+-doped samples, as well as the 2F5/2 (975 nm) band typical for Yb3+-doped samples. Under excitation at 980 nm, at room temperature, the characteristic Er3+ emission at 1530 nm was also observed with improving trend when the higher RE concentrations were applied. The results indicate that the PMMA reveals very low tendency to the RE clustering, which together with low cost and easy fabrication make it a material with a great potential in the active photonics devices. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
    Polymer Engineering and Science 05/2009; 49(9):1814 - 1817. · 1.24 Impact Factor
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    Tomáš Grygar, Libor Č Apek, Jiří Adam, Vladimír Machovič
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    ABSTRACT: a b s t r a c t Voltammetry of immobilized microparticles (VMP), diffuse reflectance UV–vis spectroscopy (DRS), X-ray powder diffraction (XRD), and Raman spectroscopy were used to identify V(V) oxidic species in vanadia catalysts supported on titania, alumina, mesoporous silicas, and composites of Al 2 O 3 and TiO 2 with mont-morillonite (MMT). V 2 O 5 was detected by VMP irrespective of its crystallinity at concentrations close to the detection limit of crystalline V 2 O 5 by XRD. The interpretation of DRS was re-evaluated after VMP anal-yses, because detection of lower concentrations of V 2 O 5 by DRS is complicated by partial overlap of their absorption bands with rather intense absorption bands of major oligomeric vanadate species, while sen-sitivity of VMP to V 2 O 5 is much better than to less condensed vanadates. VMP selectively identified poly-vanadates prevailing on TiO 2 supports and oligomeric vanadate species prevailing on alumina at medium V-loadings. XRD-nanocrystalline V 2 O 5 was found as major species on impregnated mesoporous silicas with V loading above 4 wt.%. Al-and Ti-chemically modified MMTs disperse V(V) oxide species preferen-tially either on the Al 2 O 3 or TiO 2 components, or on the aluminosilicate components; these cases are eas-ily distinguished by VMP. VMP, especially if combined with spectral and XRD analyses, can produce detailed information about V(V) oxidic forms at V-loading close to or slightly above the critical monomer monolayer concentration, where 2-D and 3-D condensation of [VO 4 ] units is initiated. These forms play an important role in functionality of heterogeneous catalysts in oxidative dehydrogenation of ethane.
    Journal of Electroanalytical Chemistry - J ELECTROANAL CHEM. 01/2009; 633(1).
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    ABSTRACT: Bismuth(III)-doped epoxy Novolak resin as a novel promising photonics material was designed for applications in 1310 nm. The samples was fabricated by spin-coating and its optical properties are evaluated in the terms on bismuth(III) concentration.
    01/2009;
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    ABSTRACT: The utilization of low-grade clay materials as selective sorbents represents one of the most effective possibilities of As removal from contaminated water reservoirs. The simple pre-treatment of these materials with Fe (Al, Mn) salts can significantly improve their sorption affinity to As oxyanions. The natural kaolin calcined at 550 degrees C (mostly metakaolin) and raw bentonite (mostly montmorillonite) pre-treated with Fe(II), Fe(III), Al(III) and Mn(II) salts were used to remove of As from the model anoxic groundwater with As(III) concentration about 0.5 and 10 mg L(-1). All the pre-treating methods were appropriate for bentonite; the efficiency of As(III) sorption varied from 92 to >99%, by the sorption capacity higher than 4.5 mg g(-1). In the case of metakaolin, Fe(II)- and Mn(II)-treatments proved the high sorption efficiency (>97%), while only <50% of As was removed after Fe(III) and Al(III) pre-treatment. The sorption capacities of treated metakaolin ranged from 0.1 to 2.0 mg g(-1).
    Journal of hazardous materials 10/2008; 165(1-3):134-40. · 4.33 Impact Factor
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    ABSTRACT: We report about properties of epoxy novolak resin polymer doped with dysprosium ions. The polymer layers were fabricated by spin-coating onto silicon substrates, or pouring epoxy novolak resin solution into bottomless molds placed on a quartz substrate and leaving them to dry. Rather strong bands around 3366 cm-1 in the infrared spectra indicated presence of the O-H groups. Absorption measurements were done in the spectral range from 300 nm to 3000 nm and showed six strong bands at 758 nm (6F3/2), 807 nm (6F5/2), 906 nm (6F7/2), 1100 nm (6F9/2), 1280 nm (6F11/2) and 1685 nm (6H11/2) corresponding to Dy3+ ions. Optical band gap Eg was determined from the absorption coefficient values using Tauc's procedure, i.e., from the relationship alphahv = A(hv - Eg)2 and the obtained values varied from 3.489 eV to 3.539 eV depending on the amount of dysprosium ions involved in the samples. Photoluminescence spectra around 1300 nm were investigated by using excitation of He-Ne laser (632.8 nm) and two semiconductor lasers (980 nm and 827 nm).
    Proc SPIE 08/2008;
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    ABSTRACT: Marine black shales of the Lower Cambrian Niutitang Formation in southern China host Mo–Ni–platinum group elements (PGE) mineralization confined to a phosphate- and pyrite-rich stratiform body (max. 20-cm thick). The H/C atomic ratio, carbon isotopic composition, FTIR spectra of bulk organic matter, and spectra of extractable part of organic matter indicate similar sources and thermal evolution of organic matter in barren and mineralized black shales.The morphology and relative abundance of organic particles in barren and mineralized shales are different. In barren black shales, organic particles comprise only elongated bodies and laminae 2–10 μm across or elongated larger bodies (> 10 μm) with Rmax = 2.96–5.21% (Type I particles). Mineralized black shales contain Type I particles in rock matrix (90–95 vol%), small veinlets or irregular organic accumulations (Type II particles, 1–5 vol%) that display weak to well developed mosaic texture and a variable reflectance (Rmax = 3.55–8.65%), and small (< 1 to 5 μm) rounded or irregular Type III organic particles (1–4 vol%) distributed within phosphate nodules and sulphide rip-up clasts. Type III particles show similar reflectance as particles of Type I in rock matrix. Type I particles are interpreted as remnants of in situ bacterially reworked organic matter of cyanobacteria/algal type, Type II as solidified products or oil-derived material (migrabitumen), and Type III particles as remnants of original organic matter in phosphatized or sulphidized algal/microbial oncolite-like bodies. Equivalent vitrinite reflectances of Type I and III particles in barren and mineralized rocks are similar and correspond to semi-anthracite and anthracite. Micro-Raman spectra of organic particles in rocks display a wide belt in the area of 1600 cm− 1 (G belt) and approximately the same belt in the area of 1350 cm− 1 (D belt). The ratio of integrated areas of the two belts correlate with Rmax values.The Mo–Ni–PGE mineralized body is interpreted as to represent a remnant of phosphate- and sulphide-rich subaquatic hardground supplied with organic material derived from plankton and benthic communities as well as with algal/microbial oncolite-like bodies that originated in wave-agitated, shallow-water, nearshore environment.
    International Journal of Coal Geology 11/2007; · 3.31 Impact Factor

Publication Stats

290 Citations
81.20 Total Impact Points

Institutions

  • 1994–2014
    • Academy of Sciences of the Czech Republic
      • Institute of Rock Structure and Mechanics
      Praha, Praha, Czech Republic
  • 2009
    • University of Pardubice
      • Department of Physical Chemistry
      Pardubice, Pardubicky kraj, Czech Republic
  • 2006
    • Institute of Chemical Technology Prague
      • Department of Chemistry of Solid State
      Praha, Hlavni mesto Praha, Czech Republic