Vol. 11 No. 2 (2021) | Bulletin of Natural Sciences Research

Open Access Original Scientific Paper

COMPARISON OF TRANSITION RATES WITH THE LG (0, 1)* SPIRAL-PHASE MODE FIELD DISTRIBUTION IN THE FRAME OF THREE IONIZATION THEORIES

by Tatjana B. Miladinović, Nebojša S. Danilović

We discussed the tunneling ionization of an Argon atom placed in a strong low-frequency field of Ti: Sapphire laser. The transition rate of the electron obtained with radial polarization LG (0, 1)* spiral-phase mode field distribution included are compared to the basic transition rate. All analyses are given in the frame of the three different ionization theories – Keldysh, PPT, and ADK. We demonstrated that the tunneling transition rate is sensitive to laser polarization and a set field distribution. As well as changes in the azimuthal angle as a parameter on which the given distribution depends.

View Full-Text DOI 10.5937/bnsr11-28954 Published: 22 Dec 2021

Open Access Original Scientific Paper

LIGHT CAPTURING WITHIN THE DEFECT LOCATED IN LINEAR ONE-DIMENSIONAL PHOTONIC LATTICE

by Slavica Jovanović, Marija Stojanović Krasić

Numerically investigated the light beam propagation through one-dimensional photonic lattice possessing one linear defect. It is shown how capturing of light depends on lattice characteristics as well as the width and wavelength of input light beam. Results may be useful for all-optical control of transmission of waves in interferometry.

View Full-Text DOI 10.5937/bnsr11-31292 Published: 21 Dec 2021

Open Access Original Scientific Paper

NEW DATA ON THE DISTRIBUTION OF LEPIDOPTERA IN MONTENEGRO, WITH A REVIEW OF ABERRANT FORMS

by Predrag Jakšić, Andrew King

During the three-year period of investigations, species from the families Depressariidae Meyrick, 1883, Pyralidae Latreille, 1809, Crambidae Latreille, 1810, Lycaenidae Leach, 1815, Nymphalidae Rafinesque, 1815, Geometridae Leach, 1815 and Erebidae Leach, 1815 were investigated. Investigations were carried out in 20 localities, distributed throughout the entire territory of Montenegro. Two species are listed for Montenegro for the first time: Hypoxystis pluviaria (Fabricius, 1787) and Aspitates ochrearia (Rossi, 1794).

View Full-Text DOI 10.5937/bnsr11-29876 Published: 15 Dec 2021

Open Access Original Scientific Paper

DIATOM SPECIES COMPOSITION AND THEIR SEASONAL DYNAMICS IN THE TIMOK RIVER BASIN

by Nikola Đukic, Tatjana Jakšić, Olivera Papović, Predrag Vasić

The aim of this paper was to present the composition and seasonal dynamics of epilthic diatoms in the Timok River basin. The diatom samples were collected along the Timok River basin in March, May, August and November 2017. Permanent diatom slides were prepared after oxidizing the organic material by the hydrogen peroxide (H2O2). The cleaned diatom materials were mounted on permanent slides using ZRAX glue. A total of 85 taxa were identified in the Timok River Basin. The benthic diatom taxa belong to 31 genera with the highest diversity observed within Navicula Bory (15), Nitzschia Hassall (12) and Gomphonema Ehrenberg (8). Quantitative analysis showed that in all seasons, Achnanthidium minutissimum and Amphora pediculus were dominant taxa. In May, they were joined by the Achnanthidium pyrenaicum, Gomphonema olivaceum and Ulnaria ulna; in August by the Cocconeis placentula, Denticula kuetzingii, Melosira varians, Navicula metareichardtiana, Nitzschia capitellata, N. fonticola and N. palea; in November by the D. kuetzingii, G. olivaceum, G. pumilum, N. metareichardtiana, N. veneta, Nitzschia capitellata and N. palea and in March by A. pyrenaicum, Diatoma moniliformis, G. olivaceum, N. palea and U. ulna. Our research is the floristical and ecological study of benthic diatoms in this basin and can form the groundwork for further research work.

View Full-Text DOI 10.5937/bnsr11-25709 Published: 14 Dec 2021

Open Access Original Scientific Paper

INFLUENCE OF THE ACIDITY OF THE IODOUS ACID SOLUTION SYSTEM ON THE KINETICS OF THE DISPROPORTIONATION REACTION

by Smiljana Marković

Influence of the acidity of the iodous acid (HOIO) solution system on the kinetics disproportionation reaction is examined in aqueous sulfuric acid solution (0.125 moldm-3). The disproportionation reaction rate constants were determined at 285, 291, 298 and 303 K based on data obtained under stationary conditions. The calculated rate constants increase with increasing temperature for different values of iodous acid and iodate concentrations. The average activation energy of 46 kJmol-1 was determined for the chosen temperature interval, by a graphical method. The values of pseudo-equilibrium concentrations of kinetically important and catalytic species H+, H2OI+ i IO3- in the disproportionation reaction were determined for the given experimental conditions based on the equilibrium dissociation reactions of sulfuric and iodous acids in the quasi-stationary state. The estimated values of sulfuric and iodous acid are predominant and higher than the concentration of the protonated ion of H2OI+.

View Full-Text DOI 10.5937/bnsr11-29311 Published: 05 Dec 2021

Open Access Original Scientific Paper

ULTRASOUND-ASSISTED SYNTHESIS OF NOVEL 3-(PYRIDINYLAMINO)-1-FERROCENYLPROPAN-1-ONES

by Aleksandra Minić Jančić, Danijela Ilić Komatina, Anka Todosijević, Dragana Stevanović

In this work we will report the formulation of novel 3-(pyridinylamino)-1-ferrocenylpropan-1-ones. A fruitful aza-Michael addition of pyridinamine moiety to a conjugated enone, 1-ferrocenylpropenone, has been accomplished by an ultrasonic irradiation of the mixture of these reactants. As the catalyst montmorillonite K-10 has been used and the reaction has been carried out as solvent-free, yielding ferrocene containing Mannich bases, compounds considered as important precursors in organic synthesis. The reaction score has been evaluated on three examples. The prepared products have been purified by column chromatography. In addition, a detailed characterization of the obtained 3-(pyridin-2-ylamino)-1-ferrocenylpropan-1-on and 3-(pyridin-3-ylamino)-1-ferrocenylpropan-1-on has been completed by IR and NMR spectroscopy, as well as elemental analyses.

View Full-Text DOI 10.5937/bnsr11-30426 Published: 01 Dec 2021