University of Tuzla (Serbo-Croatian: Univerzitet u Tuzli) is a public university located in Tuzla, Bosnia and Herzegovina. The university was founded in 1958. It became a proper university in 1976, and today is one of the major institutions of higher learning in Bosnia and Herzegovina.In the academic year of 2014–2015, the total number of enrolled students in all faculties and academies was 10,683. The total number of enrolled students has shown a steady decline from the academic year 2010–2011, when 14,212 students were enrolled at the university.
Biological invasions, driven by the spread of non-native species, have become a critical global issue because of their far-reaching ecological and socioeconomic impacts. Effective communication of the risks of biological invasions is essential for implementing robust policy and legislation and gaining public support for conservation efforts. However, current policies often suffer from fragmentation and ineffectiveness, largely due to inadequate risk communication and complex multi-level governance. To address this challenge, we develop a global framework designed to enhance clearer communication about biological invasion risks. The framework contextualizes key terms across three domains in invasion science: species invasiveness, risk analysis, and decision support tools. Using both diffusion-of-English and ecology-of-language paradigms, and following a three-step process involving preliminary consensus, AI querying, and ground-truthing with final consensus, we validate the framework in 70 non-English languages which, together with English, have official status in at least one country and collectively cover all 195 countries worldwide. Our findings reveal that while terminology for risk analysis is well established, terminology for species invasiveness and, especially, for decision support tools remains underdeveloped in many languages, hindering effective communication and policy implementation. Our framework underscores the importance of cultural and political neutrality. By promoting clearer risk communication among scientists, policymakers, and the public globally, we aim to reduce policy fragmentation and foster enhanced collaboration in risk mitigation. We recommend expanding multilingual decision support tools to include the full risk analysis process: risk identification, risk assessment, and risk management. This will support intergovernmental mitigation efforts and promote a unified global response to biological invasions.
This paper investigates the dynamics of a discrete-time Rayleigh-Duffing oscillator exhibiting chaos in the Li-Yorke sense. We use Marotto's theorem to prove the existence of chaos by finding a snap-back repeller. It is shown that the system undergoes Neimark-Sacker and a period-doubling bifurcations. We compute the Lyapunov exponents numerically to show sensitive dependence on initial conditions and chaotic behavior. The results are illustrated using numerical simulations.
This paper deals with a time series of blackout events of the power transmission system in the Federation of Bosnia and Herzegovina (FB H) in the period 2015–2023 and probability distributions that best fit these empirical data. The present study focuses on the global behaviour and dynamics of time series, ignoring the details of particular failures. We compiled the first comprehensive blackouts database in FB H including the relevant information on each blackout feature. Most existing investigations concentrate on large-scale transmission systems, with limited evidence available for smaller and more compact grids. This study contributes new insight by investigating whether the heavy-tailed scaling observed in large systems also emerges in the FB H transmission network. The power-law behaviour of the transmission network failure events in the FB H power grid depending on their severity was identified. The estimated power-law exponent α is not merely a descriptive parameter but also reflects the underlying vulnerability of the system, making comparisons across countries valuable for assessing resilience and risk in transmission networks of different sizes and configurations. The results of this study show that the time intervals between the blackout events follow the exponential distribution. The data available from the FB H power grid transmission centres in the observed period indicate that the frequency of all the blackout events in FB H is not decreasing. It was determined that the blackout probability increases substantially during the morning hours, while the number of blackout events increases during the early summer and mid-fall months. However, the correlation analysis results show that there is only a weak, statistically insignificant correlation between blackout size and restoration time. The results for the FB H power system, which relies predominantly on thermal power plants, indicate that despite differences in system scale and in the structure of electricity production compared with most EU power systems, no significant deviations are observed in blackout size behaviour when described by a power-law model. The results of this study provide a set of unique and valuable insights to operators and decision makers for the safe operation of the FB H power system. The broader scope of applications of the results obtained includes the connection of the FB H power system to power distribution across the Balkans for transfers and trading.
This paper presents a simulation-based analysis of power circuits used in Type A LED lamps. Equivalent time-domain models of LED lamp power circuits are developed and implemented in PSIM, considering different load representations commonly employed in practical LED drivers, including constant-current and constant-power characteristics. The proposed models enable investigation of voltage and current waveforms as well as their spectral characteristics. Simulation results are used to illustrate waveform distortion and harmonic-related phenomena associated with the rectifier and DC-link stages. The presented approach provides a simple and flexible framework for the simulation and harmonic analysis of Type A LED lamp power circuits.
Very thin ZnO films were fabricated on p-type Si (100) substrates using two different solvents, methanol (M) and 2-methoxyethanol (2M), via a simple spin-coating method. Five-layer ZnO films were characterized structurally using X-ray diffraction (XRD), with detailed analysis performed using the Williamson–Hall (W-H) method. Surface morphology was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM), while ultraviolet–visible (UV–Vis) spectroscopy provided optical properties, including the optical band gap determined via the Kubelka–Munk theory. The crystallite sizes calculated from W-H models were larger than those estimated by the Debye–Scherrer method, indicating that peak broadening is influenced by both crystallite size and lattice strain. Strain, stress, and deformation energy density values, derived from the Uniform Deformation Model (UDM), Uniform Stress Deformation Model (USDM), and Uniform Deformation Energy Density Model (UDEDM), respectively, were higher in films prepared with 2-methoxyethanol than methanol. ZnO films from 2-methoxyethanol exhibited greater homogeneity and lower surface roughness, while their optical band gap (~3.3 eV) was slightly higher than that of methanol-derived films (~3.02 eV) but still below bulk ZnO (3.37 eV). These results show that ZnO thin films prepared with 2-methoxyethanol exhibit superior microstructural, mechanical, and optical properties, producing smoother and more uniform films with enhanced optical characteristics, and are therefore more commonly preferred for optoelectronic and photovoltaic applications due to their improved crystallinity, low surface roughness, and suitable band gap.
