New longhorn beetles (Coleoptera: Cerambycidae) from Serbia

The most recent data (Ilić, 2005) indicate the presence of 245 longhorn beetle species (Coleoptera: Cerambycidae) in Serbia. Not included in the mentioned publication, the following five species should be added to the list: Cortodera discolor Fairmaire, 1866; Stenopterus similatus Holzschuh 1979; Chlorophorus aegyptiacus (Fabricius, 1775); Agapanthia osmanlis (Reiche, 1858); Agapanthia maculicornis (Gyllenhal, 1817) (Pil and Stojanović in press). A total number of 250 species are presently known for the Serbian longhorn beetle fauna

Inflationary RSII Model with a Matter in the Bulk and Exponential Potential of Tachyon Field

In this paper we study a tachyon cosmological model based on dynamics of a 3-brane in the second Randall-Sundrum (RSII) model extended to include matter in the bulk. The presence of matter in the bulk changes warp factor which leads to modification of inflationary dynamics. The additional brane behaves effectively as a tachyon. We calculate numerically observation parameters of inflation: the scalar spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) for the exponential potential of tachyon field.Comment: 9 pages, 1 figure, will be published in the Special Issue of Facta Universitatis, Series: Physics, Chemistry and Technology devoted to the SEENET-MTP Balkan Workshop BSW2018 (3-14 June 2018

Numerical Calculation of Hubble Hierarchy Parameters and Observational Parameters of Inflation

We present results obtained by a software we developed for computing observational cosmological inflation parameters: the scalar spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) for a standard single field and tachyon inflation, as well as for a tachyon inflation in the second Randall-Sundrum model with an additional radion field. The calculated numerical values of observational parameters are compared with the latest results of observations obtained by the Planck Collaboration. The program is written in C/C++. The \textit{GNU Scientific Library} is used for some of the numerical computations and R language is used for data analysis and plots.Comment: 8 pages, 5 figures, based on talk presented at The 10th Jubilee Conference of the Balkan Physical Union (BPU10), 26-30 August 2018 (Sofia, Bulgaria

Solving the problem of general capacitor placement in radial distribution systems with laterals using simulated annealing

'Simulacija kaljenja' je prvi put primenjena za rešavanje problema kompenzacije reaktivne snage od strane grupe inženjera sa Kornel Univerziteta, Itaka, Nju Jork 1990-ih godina. To je metoda koja traga za globalnim optimumom funkcije cilja a ne zaglavljuje kod lokalnih optimuma čiji broj raste sa povećavanjem dimenzije problema. Originalne metode rešavanja problema kroz razvijene programe su prikazane. Bolja konvergencija se postiže inicializacijom algoritma sa rigoroznijim vrednostima parametara i to još uvek za prihvatljivo računarsko (CPU) vreme.Simulated annealing was introduced as the algorithm for solving general capacitor placement problem by a group of engineers from Cornell University Ithaca, New York in 1990s. It is the method which searches for a global optimum of the objective function rather than being stuck to the local optima whose number grows as problem dimension increases. In the developed programs, original methods for solving the problem are introduced. Optimum is reached by initializing an algorithm with more rigorous parameters and for reasonable amount of CPU time

Solving the problem of general capacitor placement in radial distribution systems with laterals using simulated annealing

'Simulacija kaljenja' je prvi put primenjena za rešavanje problema kompenzacije reaktivne snage od strane grupe inženjera sa Kornel Univerziteta, Itaka, Nju Jork 1990-ih godina. To je metoda koja traga za globalnim optimumom funkcije cilja a ne zaglavljuje kod lokalnih optimuma čiji broj raste sa povećavanjem dimenzije problema. Originalne metode rešavanja problema kroz razvijene programe su prikazane. Bolja konvergencija se postiže inicializacijom algoritma sa rigoroznijim vrednostima parametara i to još uvek za prihvatljivo računarsko (CPU) vreme.Simulated annealing was introduced as the algorithm for solving general capacitor placement problem by a group of engineers from Cornell University Ithaca, New York in 1990s. It is the method which searches for a global optimum of the objective function rather than being stuck to the local optima whose number grows as problem dimension increases. In the developed programs, original methods for solving the problem are introduced. Optimum is reached by initializing an algorithm with more rigorous parameters and for reasonable amount of CPU time

Rat duodenal motility in vitro: Prokinetic effects of DL-homocysteine thiolactone and modulation of nitric oxide mediated inhibition

Homocysteine is a significant but modifiable risk factor for vascular diseases. As gastrointestinal smooth musculature is similar to blood vessel muscles, we investigated how elevated homocysteine levels affect nitric oxide-mediated neurotransmission in the gut. There is accumulated evidence that a dysfunction of NO neurons in the myenteric plexus may cause various diseases in the gastrointestinal tract such as achalasia, diabetic gastroparesis and infantile hypertrophic pyloric stenosis. In the present study, we aimed to assess the effects of homocysteine on NO-mediated responses in vitro, and to examine the effects of DL-homocysteine thiolactone on the spontaneous motility of rat duodenum and nitrergic neurotransmission. DL-homocysteine thiolactone concentration of 10 μmol/L leads to the immediate increase in tone, amplitude and frequency of spontaneous movements in isolated rat duodenum. L-NAME (30 μmol/L) leads to an increase in basal tone, amplitude and frequency of spontaneous contractions. The relaxations induced by EFS were significantly reduced in duodenal segments incubated in DL-homocysteine thiolactone compared with the control group. EFS-induced relaxations were inhibited by L-NAME in both experimental and control groups. These results suggest that a high level of homocysteine causes an important impairment of non-adrenergic non-cholinergic innervation of the rat duodenum. [Projekat Ministarstva nauke Republike Srbije, br. 175043

Controlling qubit arrays with anisotropic XXZ Heisenberg interaction by acting on a single qubit

We investigate anisotropic XXZ Heisenberg spin-1/2 chains with control fields acting on one of the end spins, with the aim of exploring local quantum control in arrays of interacting qubits. In this work, which uses a recent Lie-algebraic result on the local controllability of spin chains with "always-on” interactions, we determine piecewise-constant control pulses corresponding to optimal fidelities for quantum gates such as spin-flip (NOT), controlled-NOT (CNOT), and square-root-of-SWAP (). We find the minimal times for realizing different gates depending on the anisotropy parameter Δ of the model, showing that the shortest among these gate times are achieved for particular values of Δ larger than unity. To study the influence of possible imperfections in anticipated experimental realizations of qubit arrays, we analyze the robustness of the obtained results for the gate fidelities to random variations in the control-field amplitudes and finite rise time of the pulses. Finally, we discuss the implications of our study for superconducting charge-qubit array

Optimization and implementation of the wavelet based algorithms for embedded biomedical signal processing

Existing biomedical wavelet based applications exceed the computational, memory and consumption resources of low-complexity embedded systems. In order to make such systems capable to use wavelet transforms, optimization and implementation techniques are proposed. The Real Time QRS Detector and De-noising Filter are developed and implemented in 16-bit fixed point microcontroller achieving 800 Hz sampling rate, occupation of less than 500 bytes of data memory, 99.06% detection accuracy, and 1 mW power consumption. By evaluation of the obtained results it is found that the proposed techniques render negligible degradation in detection accuracy of -0.41% and SNR of -2.8%, behind 2-4 times faster calculation, 2 times less memory usage and 5% energy saving. The same approach can be applied with other signals where the embedded implementation of wavelets can be beneficial

Study on a standard for grounding systems realization

Grounding systems of objects inside power facilities are very often realized as structures consisting of protective electrodes’ system placed in the object foundation, and neutral electrodes’ system placed at a specified distance from the object. Official standards and publications recommend a minimal value for the distance between the protective and the neutral part of grounding structures, so that the influence of one on another can be neglected. We analyze several practical implementations of grounding structures and demonstrate that the minimal distance is actually much smaller than that recommended by the standards

Aurivillius BaBi4Ti4O15 based compounds: Structure, synthesis and properties

The discovery of some Aurivillius materials with high Curie temperature or fatigue-free character suggests possible applications in high temperature piezoelectric devices or non-volatile ferroelectric random access memories. Furthermore, increasing concerns for environmental issues have promoted the study of new lead-free piezoelectric materials. Barium bismuth titanate (BaBi4Ti4O15), an Aurivillius compound, is promising candidate to replace lead-based materials, both as lead-free ferroelectric and high temperature piezoelectric. In this review paper, we report a detailed overview of crystal structure, different synthesis methods and characteristic properties of barium bismuth titanate ferroelectric materials