marija krmar - Academia.edu (original) (raw)
Papers by marija krmar
Journal of Molecular Spectroscopy, Aug 1, 2001
Journal of The Serbian Chemical Society, 2005
The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in... more The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in spectra of spatially and spin degenerate electronic states of triatomic and tetra-atomic molecules. The main goal of the present paper is to show that such theoretical investigations can be used to reliably reproduce, explain and predict the results of the corresponding measurements.
Journal of Hazardous Materials, 2015
In this study, the adsorption of pharmaceutically active compounds-salicylic acid, acetylsalicyli... more In this study, the adsorption of pharmaceutically active compounds-salicylic acid, acetylsalicylic acid, atenolol and diclofenac-Na onto activated carbons has been studied. Three different commercial activated carbons, possessing ∼ 650, 900 or 1500 m 2 g-1 surface areas were used as solid adsorbents. These materials were fully characterized-their textural, surface features and points of zero charge have been determined.
During plasma electrolytic oxidation of a magnesium alloy (96 % Mg, 3 % Al and 1 % Zn), a lumines... more During plasma electrolytic oxidation of a magnesium alloy (96 % Mg, 3 % Al and 1 % Zn), a luminescence spectrum in the wave number range between 19950 and 20400 cm -1 was obtained. The broad peak with a clearly pronounced structure was assigned to the v'-v" = 0 sequence of the B 1 Σ + → X 1 Σ + electronic transition of MgO. Quantum-mechanical perturbative approach was applied to extract the form of the potential energy curves for the electronic states involved in the observed spectrum, from the positions of the spectral bands. These potential curves, combined with the results of quantum-chemical calculations of the electric transition moment, were employed in subsequent variational calculations to obtain the Franck-Condon factors and transition moments for the observed vibrational transitions. Comparing the results of these calculations with the measured intensity distribution within the spectrum, the relative population of the upper electronic state vibration levels was de...
Contemporary Materials, 2011
The results obtained in the parallel testing of the epoxy-glass composite specimen, using convent... more The results obtained in the parallel testing of the epoxy-glass composite specimen, using conventional mechanical methods and thermography, are presented. The tensile properties of composite were followed by thermography. The temperature changes on the tested sample were continuously recorded enabling the prediction of the critical stresses, which might cause the fractures and to define the criteria on the maximum sample temperature alteration in the field of the elastic and elastic-plastic deformation of investigated specimen.
Journal of Hazardous Materials, 2015
In this study, the adsorption of pharmaceutically active compounds-salicylic acid, acetylsalicyli... more In this study, the adsorption of pharmaceutically active compounds-salicylic acid, acetylsalicylic acid, atenolol and diclofenac-Na onto activated carbons has been studied. Three different commercial activated carbons, possessing ∼ 650, 900 or 1500 m 2 g-1 surface areas were used as solid adsorbents. These materials were fully characterized-their textural, surface features and points of zero charge have been determined.
The Journal of Chemical Physics, 1999
Results of an ab initio treatment of the Renner–Teller effect in the ground electronic state of H... more Results of an ab initio treatment of the Renner–Teller effect in the ground electronic state of HCCD+ are presented. The model Hamiltonian employed involves four nuclear degrees of freedom correlating at linear geometry with two degenerate bending vibrations. Computations of vibronic energy levels and wave functions are carried out by means of a variational approach. The results of calculations are compared with those for symmetric isotopic species HCCH+ and DCCD+.
Chemical Physics, 2006
With the present paper we begin an extensive study of the Renner-Teller effect in linear and quas... more With the present paper we begin an extensive study of the Renner-Teller effect in linear and quasilinear tetra-atomic molecules. Although this topic has been the subject of considerable work carried out by the present authors and their colleagues, there are a number of critical points that have not been discussed profoundly enough, so that we feel it necessary to elucidate them in more detail. This particularly concerns the relationship between the Renner-Teller effect in tetra-atomic molecules and related coupling mechanisms appearing in triatomics, as well as avoided crossings, conical intersections and Jahn-Teller effect in nonlinear high-symmetry species. In the present paper we introduce various types of coordinates and derive general forms of the model bending Hamiltonian for molecules in P, D, and U electronic states.
Journal of Molecular Spectroscopy, Dec 1, 2000
Large-scale CI calculations are carried out to obtain accurate potential energy surfaces for the ... more Large-scale CI calculations are carried out to obtain accurate potential energy surfaces for the … π2g manifold (X3Σ−g, 11Δg, 11Σ+g) of electronic states of NCN. Separation of the low-lying singlet states from the triplet ground state is computed in close agreement with the results of a recent photoelectron study by T. R. Taylor, R. T. Bise, K. R. Asmis, and
Metallurgical and Materials Engineering, Jul 2, 2018
Corrosion behavior of metalized layers, obtained by Plasma Transferred Arc (PTA) process and by H... more Corrosion behavior of metalized layers, obtained by Plasma Transferred Arc (PTA) process and by High-Velocity Oxygen Fuel (HVOF) process with the purpose to improve the wear resistance of vital parts of ventilation mill in a thermal power plant, has been tested. The test is performed using three electrochemical techniques, in a solution containing chloride and sulfate ions. It is shown that the steel surface (base metal) dissolves uniformly, without pitting or other forms of local dissolution. Morphology of metalized layers surface indicates that dissolution is non-uniform, but it still can be considered as general corrosion. The corrosion rate of base metal and metalized layer obtained by PTA process is rather low, while the corrosion rate of the metalized layer obtained by HVOF process is much higher. Also, the difference in corrosion potentials between the base metal and the HVOF layer is pretty high but slightly less than maximum allowed difference (prescribed by the standard), to avoid excessive galvanic corrosion. The values of corrosion rate obtained by different electrochemical techniques are in excellent agreement.
Journal of the Serbian Chemical Society
A systematic study of various effects on the structure of the spectra of linear triatomic molecul... more A systematic study of various effects on the structure of the spectra of linear triatomic molecules in the 3P electronic states has been carried out. Paricular attention was paid to the interplay between the vibronic and spin-orbit couplings. Variational and perturbative computations at various levels of sophistication were performed fot the A3Pu state of the NCN radical.
J Mol Spectrosc, 2000
Large-scale CI calculations are carried out to obtain accurate potential energy surfaces for the ... more Large-scale CI calculations are carried out to obtain accurate potential energy surfaces for the … π2g manifold (X3Σ−g, 11Δg, 11Σ+g) of electronic states of NCN. Separation of the low-lying singlet states from the triplet ground state is computed in close agreement with the results of a recent photoelectron study by T. R. Taylor, R. T. Bise, K. R. Asmis, and
The influence of the substrate position in the different regions of the plasma jet was examined d... more The influence of the substrate position in the different regions of the plasma jet was examined depending on the morphology, deposition rate, surface area of the deposited diamond films and their phase purity while other parameters of the process were kept constant (CH 4 /H 2 ratio, plasma power, chamber pressure and substrate temperature). An increase in the substrate distance from the anode nozzle opening of the torch leads to a considerable change in morphology (from a perfect crystallinity to a ball-like structure), as well as to a decrease in deposition rate and an increase in the coated surface area. According to XRD findings, the phase purity of the deposits does not deteriorate significantly, so it can be described as a diamond coating in the entire region studied. A reason could be the enthalpy of plasma gases high enough to preserve a relatively high concentration of atomic hydrogen which is known as a good etchant for non-diamond carbon phases.
Journal of the Serbian Chemical Society, 2005
The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in... more The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in spectra of spatially and spin degenerate electronic states of triatomic and tetra-atomic molecules. The main goal of the present paper is to show that such theoretical investigations can be used to reliably reproduce, explain and predict the results of the corresponding measurements.
Journal of the Serbian Chemical Society, 2012
During plasma electrolytic oxidation of a magnesium alloy (96 % Mg, 3 % Al and 1 % Zn), a lumines... more During plasma electrolytic oxidation of a magnesium alloy (96 % Mg, 3 % Al and 1 % Zn), a luminescence spectrum in the wave number range between 19950 and 20400 cm-1 was obtained. The broad peak with a clearly pronounced structure was assigned to the v′-v″ = 0 sequence of the B 1 Σ + → X 1 Σ + electronic transition of MgO. Quantum-mechanical perturbative approach was applied to extract the form of the potential energy curves for the electronic states involved in the observed spectrum, from the positions of the spectral bands. These potential curves, combined with the results of quantum-chemical calculations of the electric transition moment, were employed in subsequent variational calculations to obtain the Franck-Condon factors and transition moments for the observed vibrational transitions. Comparing the results of these calculations with the measured intensity distribution within the spectrum, the relative population of the upper electronic state vibration levels was derived. This enabled the plasma temperature to be estimated. Additionally, the temperature was determined by analysis of the recorded A 2 Σ + (v′ = 0)-X 2 П (v″ = 0) emission spectrum of OH. The composition of the plasma containing magnesium, oxygen, and hydrogen under the assumption of a local thermal equilibrium was calculated in the temperature range up to 12000 K and for pressures of 10 5 , 10 6 , 10 7 , and 10 8 Pa, in order to explain the appearance of the observed spectral features and to contribute to the elucidation of processes occurring during the electrolytic oxidation of Mg.
Journal of Molecular Spectroscopy, Aug 1, 2001
Journal of The Serbian Chemical Society, 2005
The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in... more The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in spectra of spatially and spin degenerate electronic states of triatomic and tetra-atomic molecules. The main goal of the present paper is to show that such theoretical investigations can be used to reliably reproduce, explain and predict the results of the corresponding measurements.
Journal of Hazardous Materials, 2015
In this study, the adsorption of pharmaceutically active compounds-salicylic acid, acetylsalicyli... more In this study, the adsorption of pharmaceutically active compounds-salicylic acid, acetylsalicylic acid, atenolol and diclofenac-Na onto activated carbons has been studied. Three different commercial activated carbons, possessing ∼ 650, 900 or 1500 m 2 g-1 surface areas were used as solid adsorbents. These materials were fully characterized-their textural, surface features and points of zero charge have been determined.
During plasma electrolytic oxidation of a magnesium alloy (96 % Mg, 3 % Al and 1 % Zn), a lumines... more During plasma electrolytic oxidation of a magnesium alloy (96 % Mg, 3 % Al and 1 % Zn), a luminescence spectrum in the wave number range between 19950 and 20400 cm -1 was obtained. The broad peak with a clearly pronounced structure was assigned to the v'-v" = 0 sequence of the B 1 Σ + → X 1 Σ + electronic transition of MgO. Quantum-mechanical perturbative approach was applied to extract the form of the potential energy curves for the electronic states involved in the observed spectrum, from the positions of the spectral bands. These potential curves, combined with the results of quantum-chemical calculations of the electric transition moment, were employed in subsequent variational calculations to obtain the Franck-Condon factors and transition moments for the observed vibrational transitions. Comparing the results of these calculations with the measured intensity distribution within the spectrum, the relative population of the upper electronic state vibration levels was de...
Contemporary Materials, 2011
The results obtained in the parallel testing of the epoxy-glass composite specimen, using convent... more The results obtained in the parallel testing of the epoxy-glass composite specimen, using conventional mechanical methods and thermography, are presented. The tensile properties of composite were followed by thermography. The temperature changes on the tested sample were continuously recorded enabling the prediction of the critical stresses, which might cause the fractures and to define the criteria on the maximum sample temperature alteration in the field of the elastic and elastic-plastic deformation of investigated specimen.
Journal of Hazardous Materials, 2015
In this study, the adsorption of pharmaceutically active compounds-salicylic acid, acetylsalicyli... more In this study, the adsorption of pharmaceutically active compounds-salicylic acid, acetylsalicylic acid, atenolol and diclofenac-Na onto activated carbons has been studied. Three different commercial activated carbons, possessing ∼ 650, 900 or 1500 m 2 g-1 surface areas were used as solid adsorbents. These materials were fully characterized-their textural, surface features and points of zero charge have been determined.
The Journal of Chemical Physics, 1999
Results of an ab initio treatment of the Renner–Teller effect in the ground electronic state of H... more Results of an ab initio treatment of the Renner–Teller effect in the ground electronic state of HCCD+ are presented. The model Hamiltonian employed involves four nuclear degrees of freedom correlating at linear geometry with two degenerate bending vibrations. Computations of vibronic energy levels and wave functions are carried out by means of a variational approach. The results of calculations are compared with those for symmetric isotopic species HCCH+ and DCCD+.
Chemical Physics, 2006
With the present paper we begin an extensive study of the Renner-Teller effect in linear and quas... more With the present paper we begin an extensive study of the Renner-Teller effect in linear and quasilinear tetra-atomic molecules. Although this topic has been the subject of considerable work carried out by the present authors and their colleagues, there are a number of critical points that have not been discussed profoundly enough, so that we feel it necessary to elucidate them in more detail. This particularly concerns the relationship between the Renner-Teller effect in tetra-atomic molecules and related coupling mechanisms appearing in triatomics, as well as avoided crossings, conical intersections and Jahn-Teller effect in nonlinear high-symmetry species. In the present paper we introduce various types of coordinates and derive general forms of the model bending Hamiltonian for molecules in P, D, and U electronic states.
Journal of Molecular Spectroscopy, Dec 1, 2000
Large-scale CI calculations are carried out to obtain accurate potential energy surfaces for the ... more Large-scale CI calculations are carried out to obtain accurate potential energy surfaces for the … π2g manifold (X3Σ−g, 11Δg, 11Σ+g) of electronic states of NCN. Separation of the low-lying singlet states from the triplet ground state is computed in close agreement with the results of a recent photoelectron study by T. R. Taylor, R. T. Bise, K. R. Asmis, and
Metallurgical and Materials Engineering, Jul 2, 2018
Corrosion behavior of metalized layers, obtained by Plasma Transferred Arc (PTA) process and by H... more Corrosion behavior of metalized layers, obtained by Plasma Transferred Arc (PTA) process and by High-Velocity Oxygen Fuel (HVOF) process with the purpose to improve the wear resistance of vital parts of ventilation mill in a thermal power plant, has been tested. The test is performed using three electrochemical techniques, in a solution containing chloride and sulfate ions. It is shown that the steel surface (base metal) dissolves uniformly, without pitting or other forms of local dissolution. Morphology of metalized layers surface indicates that dissolution is non-uniform, but it still can be considered as general corrosion. The corrosion rate of base metal and metalized layer obtained by PTA process is rather low, while the corrosion rate of the metalized layer obtained by HVOF process is much higher. Also, the difference in corrosion potentials between the base metal and the HVOF layer is pretty high but slightly less than maximum allowed difference (prescribed by the standard), to avoid excessive galvanic corrosion. The values of corrosion rate obtained by different electrochemical techniques are in excellent agreement.
Journal of the Serbian Chemical Society
A systematic study of various effects on the structure of the spectra of linear triatomic molecul... more A systematic study of various effects on the structure of the spectra of linear triatomic molecules in the 3P electronic states has been carried out. Paricular attention was paid to the interplay between the vibronic and spin-orbit couplings. Variational and perturbative computations at various levels of sophistication were performed fot the A3Pu state of the NCN radical.
J Mol Spectrosc, 2000
Large-scale CI calculations are carried out to obtain accurate potential energy surfaces for the ... more Large-scale CI calculations are carried out to obtain accurate potential energy surfaces for the … π2g manifold (X3Σ−g, 11Δg, 11Σ+g) of electronic states of NCN. Separation of the low-lying singlet states from the triplet ground state is computed in close agreement with the results of a recent photoelectron study by T. R. Taylor, R. T. Bise, K. R. Asmis, and
The influence of the substrate position in the different regions of the plasma jet was examined d... more The influence of the substrate position in the different regions of the plasma jet was examined depending on the morphology, deposition rate, surface area of the deposited diamond films and their phase purity while other parameters of the process were kept constant (CH 4 /H 2 ratio, plasma power, chamber pressure and substrate temperature). An increase in the substrate distance from the anode nozzle opening of the torch leads to a considerable change in morphology (from a perfect crystallinity to a ball-like structure), as well as to a decrease in deposition rate and an increase in the coated surface area. According to XRD findings, the phase purity of the deposits does not deteriorate significantly, so it can be described as a diamond coating in the entire region studied. A reason could be the enthalpy of plasma gases high enough to preserve a relatively high concentration of atomic hydrogen which is known as a good etchant for non-diamond carbon phases.
Journal of the Serbian Chemical Society, 2005
The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in... more The present paper reviews the results of ab initio studies on the magnetic hyperfine structure in spectra of spatially and spin degenerate electronic states of triatomic and tetra-atomic molecules. The main goal of the present paper is to show that such theoretical investigations can be used to reliably reproduce, explain and predict the results of the corresponding measurements.
Journal of the Serbian Chemical Society, 2012
During plasma electrolytic oxidation of a magnesium alloy (96 % Mg, 3 % Al and 1 % Zn), a lumines... more During plasma electrolytic oxidation of a magnesium alloy (96 % Mg, 3 % Al and 1 % Zn), a luminescence spectrum in the wave number range between 19950 and 20400 cm-1 was obtained. The broad peak with a clearly pronounced structure was assigned to the v′-v″ = 0 sequence of the B 1 Σ + → X 1 Σ + electronic transition of MgO. Quantum-mechanical perturbative approach was applied to extract the form of the potential energy curves for the electronic states involved in the observed spectrum, from the positions of the spectral bands. These potential curves, combined with the results of quantum-chemical calculations of the electric transition moment, were employed in subsequent variational calculations to obtain the Franck-Condon factors and transition moments for the observed vibrational transitions. Comparing the results of these calculations with the measured intensity distribution within the spectrum, the relative population of the upper electronic state vibration levels was derived. This enabled the plasma temperature to be estimated. Additionally, the temperature was determined by analysis of the recorded A 2 Σ + (v′ = 0)-X 2 П (v″ = 0) emission spectrum of OH. The composition of the plasma containing magnesium, oxygen, and hydrogen under the assumption of a local thermal equilibrium was calculated in the temperature range up to 12000 K and for pressures of 10 5 , 10 6 , 10 7 , and 10 8 Pa, in order to explain the appearance of the observed spectral features and to contribute to the elucidation of processes occurring during the electrolytic oxidation of Mg.