A Proposed Method for Determining Propulsion Coefficient Based on Testing Motor Freighters on Danube Waterway Network

The paper presents a proposal of mathematical models for the determination of propulsion coefficient, eta pp, intended for the analysis of motor freighters applied on the river watercourses. As the main paper contribution three different model types are developed, depending on the variable which contributes to eta pp value. These variables are: 1. the freighter sailing velocity, (nu); 2. the installed capacity of the main drive motor of outboard unit, (N-inst); 3. the combination of these two variables, (N-inst, nu). The models are verified on the examples of several motor freighters which are applied at Danube river. The special attention is paid to the determination of the optimum approximation function in each case. In all three cases it is a quadratic function. The correlation coefficient for the comparison in all analyzed examples is higher than 0.87, being even higher than 0.99 for the first model

Display probability of symbol errors for MQAM on Rician fading channel based on MGF method

We present a new method for calculating the probability of error per symbol (Symbol Error Probability, SEP) of M-ary Quadrature Amplitude Modulation (MQAM) over a slow, flat, identically independently distributed Rician fading channels. Since fading is one of the major constraints in wireless communications, the diversity modulation technique is used for the efficient transfer of message signals. Exact analysis of error probability per symbol for MQAM, transmitted over Rician fading channels, is performed by N branches of diversity reception using maximum ratio of signal-to-noise power (maximal-ratio-combining, MRC), where the information in the channel on the receiver side is known. We also analyzed the performances of MQAM over Rician fading channels are here also analyzed. Approximate formula is used to represent SEP for MQAM transmitted over Gaussian channels. Boundary condition for the approximation is M≥4 and 0≤SNR≤30 dB

Display probability of symbol errors for MQAM on Rician fading channel based on MGF method

We present a new method for calculating the probability of error per symbol (Symbol Error Probability, SEP) of M-ary Quadrature Amplitude Modulation (MQAM) over a slow, flat, identically independently distributed Rician fading channels. Since fading is one of the major constraints in wireless communications, the diversity modulation technique is used for the efficient transfer of message signals. Exact analysis of error probability per symbol for MQAM, transmitted over Rician fading channels, is performed by N branches of diversity reception using maximum ratio of signal-to-noise power (maximal-ratio-combining, MRC), where the information in the channel on the receiver side is known. We also analyzed the performances of MQAM over Rician fading channels are here also analyzed. Approximate formula is used to represent SEP for MQAM transmitted over Gaussian channels. Boundary condition for the approximation is M≥4 and 0≤SNR≤30 dB

A Proposed Method for Determining Propulsion Coefficient Based on Testing Motor Freighters on Danube Waterway Network

The paper presents a proposal of mathematical models for the determination of propulsion coefficient, eta pp, intended for the analysis of motor freighters applied on the river watercourses. As the main paper contribution three different model types are developed, depending on the variable which contributes to eta pp value. These variables are: 1. the freighter sailing velocity, (nu); 2. the installed capacity of the main drive motor of outboard unit, (N-inst); 3. the combination of these two variables, (N-inst, nu). The models are verified on the examples of several motor freighters which are applied at Danube river. The special attention is paid to the determination of the optimum approximation function in each case. In all three cases it is a quadratic function. The correlation coefficient for the comparison in all analyzed examples is higher than 0.87, being even higher than 0.99 for the first model

Scanning electron microscopy study of changes in nanoparticles surface under in vitro simulated physiological conditions

In this study we observed the changes in surface of nanoparticles of two different nanomaterials, cobalt-substituted hydroxyapatite (CoHAp) and calcium phosphate/poly-(DLlactide-co-glycolide) (CP/PLGA) that occurred under simulated physiological conditions in vitro. Both nanomaterials were incubated in an appropriate volume of Dulbecco's Modified Eagle Medium (DMEM) for 3 days at 37 0C and then the medium was removed and materials were dried. Surface changes of nanoparticles were studied by scanning electron microscopy (SEM). Results of SEM analysis show that changes in the size and shape of the nanoparticles took place. These changes can be explained by interactions of nanomaterials with DMEM. In the case of CP/PLGA it was probably the result of polymer degradation and changes in CoHAp nanoparticles were probably the result of ion exchange

Calculating the probability of error per symbol on the basis of MGF method using Rician fading for MFSK

U ovom radu se analizira verovatnoća greške po simbolu za M-arnu ne-koherentnu frekvencijsku modulaciju (M-ary Frequency Shift Keying, MFSK) signala u ambijentu frekvencijsko-neselektivnog sporog Rician fadinga i prijemnika zasnovanog na tehnici kombinovanja maksimalnog odnosa (Maximal Ratio Combining, MRC). Verovatnoće greške po simbolu su dobijene na osnovu numeričkog izračunavanja baziranog na funkciji generisanja momenta (Moment Generating Function, MGF). Pretpostavlja se da je informacija na prijemnoj strani kanala poznata. Analiza verovatnoće greške po simbolu za MFSK modulacionu tehniku izvršena je za različite vrednosti Rician faktora K, diverziti reda N i nivoa modulacije M.In this paper is presented how to calculate the probability of error per symbol of M-ary non-coherent frequency modulation (M-ary Frequency Shift Keying, MFSK) over a slow, flat, identically independently distributed Rician fading channels. SEP is calculated by technique with maximal ratio combining diverzity, using the moment generating function. We assume that the information is known on the receiving side of the channel. Probabilities of error per symbol for the modulation technique are plotted for different values of Rician factor K, diverzity order N and modulation order M

Calculating the probability of error per symbol on the basis of MGF method using Rician fading for MFSK

U ovom radu se analizira verovatnoća greške po simbolu za M-arnu ne-koherentnu frekvencijsku modulaciju (M-ary Frequency Shift Keying, MFSK) signala u ambijentu frekvencijsko-neselektivnog sporog Rician fadinga i prijemnika zasnovanog na tehnici kombinovanja maksimalnog odnosa (Maximal Ratio Combining, MRC). Verovatnoće greške po simbolu su dobijene na osnovu numeričkog izračunavanja baziranog na funkciji generisanja momenta (Moment Generating Function, MGF). Pretpostavlja se da je informacija na prijemnoj strani kanala poznata. Analiza verovatnoće greške po simbolu za MFSK modulacionu tehniku izvršena je za različite vrednosti Rician faktora K, diverziti reda N i nivoa modulacije M.In this paper is presented how to calculate the probability of error per symbol of M-ary non-coherent frequency modulation (M-ary Frequency Shift Keying, MFSK) over a slow, flat, identically independently distributed Rician fading channels. SEP is calculated by technique with maximal ratio combining diverzity, using the moment generating function. We assume that the information is known on the receiving side of the channel. Probabilities of error per symbol for the modulation technique are plotted for different values of Rician factor K, diverzity order N and modulation order M

THE WINDER DANCER POSITION CONTROL MODEL USING DIFFERENT PID CONTROL STRUCTURES AND MICROLOGIX PLC

In the cable industry, improper regulation of the winding speed of the conductor cable, i.e. the position of the tensioner (dancer) leads to improper stretching of the conductor, which significantly affects the characteristics of the final product. Winding speed control is directly related to tensioning which is an additional problem. This paper presents a system for control a cable winding device using a linear PID controller with and without control signal limitation. The system parameters were determined using integral time-weighted absolute error (ITAE) criteria and realized using a conventional PLC controller

Supplementary material for the article: Stojsavljević, A.; Rovčanin, B.; Krstić; Jagodić, J.; Borković-Mitić, S.; Paunović, I.; Živaljević, V.; Mitić, B.; Gavrović-Jankulović, M.; Manojlović, D. Cadmium as Main Endocrine Disruptor in Papillary Thyroid Carcinoma and the Significance of Cd/Se Ratio for Thyroid Tissue Pathophysiology. Journal of Trace Elements in Medicine and Biology 2019, 55, 190–195. https://doi.org/10.1016/j.jtemb.2019.06.009

Supplementary material for: [https://doi.org/10.1016/j.jtemb.2019.06.009]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3293

Assessment of trace metal alterations in the blood, cerebrospinal fluid and tissue samples of patients with malignant brain tumors

The pathogenesis of malignant brain tumors (MBTs) should be better understood due to the evident association between prolonged exposure to metals and increased risk of MBTs. The present research aimed to find trace metals that could contribute to the pathogenesis of MBTs. Essential trace elements (Mn, Co, Zn, Cu, Se) and relevant toxic metals (Al, Ni, As, Sr, Cd, Ce, Pt, Pb, U) in the serum, cell fraction (CF), cerebrospinal fluid (CSF) and cancerous tissue (CT) samples of MBT patients were analyzed. The results were compared with sex- and age-matched control groups. For the first time, this research showed that elemental profiles of serum, CF, CSF and CT samples in MBT patients were significantly altered compared to the appropriate controls, as well as that higher contents of trace elements (particularly Mn, Se, and Pb) could be involved in the pathogenesis of MBTs. However, the most noticeable change found was the elevated U content, indicating its considerable role as a major cerebral discriminator of the presence/absence of MBTs. The U/Se ratio could be considered as an appropriate blood marker in diagnostic MBT evaluation. The reported results could contribute to better understanding of the poorly understood pathogenesis of MBTs. Furthermore, the reported results could highlight a molecular basis for the pathophysiological changes caused by the hazardous effects of trace metals on brain homeostasis