Papers by Vladimir Dananić
Progress of theoretical physics. Supplement, 2000
ABSTRACT Motion of a particle in the two-dimensional lemon shaped billiard is investigated both c... more ABSTRACT Motion of a particle in the two-dimensional lemon shaped billiard is investigated both classically and quantally. Poincaré sections, periodic orbits and the wave functions are presented for selected cases. Level density fluctuations are calculated using NNSD method. Chaotic and regular classical motion of the Fermi oscillator, consisting of mass M supported by a spring with constant k and a particle of mass m falling freely and colliding with mass M, is analysed.
Journal of physics, Jun 15, 2000
Knjiga sažetaka, Osmi znanstveni sastanak Hrvatskog fizikalnog društva, 2013
Novi propisi vezani uz emisije stetnih plinova pridonijeli su razvoju novih motornih sustava (npr... more Novi propisi vezani uz emisije stetnih plinova pridonijeli su razvoju novih motornih sustava (npr. EGR u dizelovim motorima) koji vrlo ucinkovito smanjuju emisije NOx plinova u atmosferu. Međutim, istodobno dolazi i do stvaranja vece kolicine nepoželjnih taloga u motornim uljima koji se mogu adsorbirati na povrsini motora i time uzrokovati niz nepovoljnih utjecaja. Da bi se to sprijecilo, moderna motorna ulja moraju imati poboljsana disperzantna svojstva sto se postiže dodavanjem aditiva s ugrađenom funkcionalnom skupinom na temelju dusika ili kisika. Uloga funkcionalne skupine jest da dispergira cestice taloga u ulju i/ili sprjecava njihovo taloženje stvaranjem tankog povrsinskog filma na vitalnim dijelovima motora. Kako bi ustanovili interakciju između metalne povrsine motora i motornih ulja, u ovom radu ispitan je utjecaj sastava i koncentracije vise razlicitih polimernih aditiva motornih ulja na kontaktni kut mocenja tri razlicite cvrste podloge: ugljicni celik, nehrđajuci celik...
Glasnik hemicara i tehnologa Bosne i Hercegovine, 2019
The aim of this research is to detect zwittterionic structure of the aspartic acid and confirm th... more The aim of this research is to detect zwittterionic structure of the aspartic acid and confirm the experimental spectra with quantum chemical calculations. The experimental IR and Raman spectra of aspartic acid powder show no vibrational bands of OH and NH stretching in expected spectral region. We assume that zwitterionic structure of aspartic acid is responsible for lowering the frequencies of these vibrations. An extensive experimental and computational research supports this assumption. Our DFT calculation strongly suggests the need for the dielectric environment in order to stabilize the zwitterionic structure of a single molecule. The network of intermolecular hydrogen bonding between aspartic acid molecules provides this dielectric environment. The DFT quantum mechanical calculations corroborate this assumption by optimizing a four-member group of molecules, which also gives an explanation of broad IR spectrum lines.
Progress of Theoretical Physics Supplement, 2000
ABSTRACT Motion of a particle in the two-dimensional lemon shaped billiard is investigated both c... more ABSTRACT Motion of a particle in the two-dimensional lemon shaped billiard is investigated both classically and quantally. Poincaré sections, periodic orbits and the wave functions are presented for selected cases. Level density fluctuations are calculated using NNSD method. Chaotic and regular classical motion of the Fermi oscillator, consisting of mass M supported by a spring with constant k and a particle of mass m falling freely and colliding with mass M, is analysed.
Physical Review Letters, 1998
Journal of Physics: Conference Series, 2006
Density functional theory calculations using Becke's three-parameter exchange functional in ... more Density functional theory calculations using Becke's three-parameter exchange functional in combination with the Lee-Young-Parr correlation functional (B3-LYP) and standard 6-311+ G (d, p) basis set were carried out to study the conformational stability and vibrational ...
Journal of Molecular Structure, 2007
ABSTRACT A comprehensive conformational and vibrational analysis has been carried out on gamma-am... more ABSTRACT A comprehensive conformational and vibrational analysis has been carried out on gamma-aminopropyltriethoxysilane (APTES) by density functional theory (DFT) using Becke’s three-parameter exchange functional in combination with the Lee–Young–Parr correlation functional (B3LYP) and standard 6-31G(d, p) basis set. The scanning of the potential energy surface with respect to the SiCCC torsion angle suggests that there are five stable conformations. There are two minima with trans (t1, t2) conformations as well as three local minima corresponding to gauche (g1, g2, g3) conformations. The lowest energy conformer has trans-t1 structure with SiCCC dihedral angle of 178.8°. The gauche conformers with torsion angle around 70° have various orientations of ethoxy chains. The calculated barriers to the conformation interchange are: 114, 484, 1272, 1239 and 1120 cm−1 for the trans-t1 to trans-t2, trans-t1 to gauche-g1, trans-t1 to gauche-g2, trans-t2 to gauche-g2 and gauche-g2 to gauche-g3 conformers, respectively. The infrared (500–4000 cm−1) spectra and Raman (50–3500 cm−1) spectra of liquid APTES with qualitative polarization measurements have been recorded. A complete vibrational assignment for APTES conformers is supported by the normal coordinate analysis, calculated IR intensities as well as Raman activities. On the basis of the results, the vibrational spectra of APTES have been analyzed. The average error between the observed and calculated frequencies is 10 cm−1.
Journal of Membrane Science, 1996
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Papers by Vladimir Dananić