Space-Time High-Resolution Data of The Potential Insolation and Solar Duration for Montenegro

The assessment of the potential use of renewable energy resources requires reliable and precise data inputs for sustainable energy planning on a regional, national and local scale. In this study, we examine high spatial resolution grids of potential insolation and solar duration in order to determine the location of potential solar power plants in Montenegro. Grids with a 25-m spatial resolution of potential solar radiation and duration were produced based on observational records and publicly available high-resolution digital elevation model provided by the European Environment Agency. These results could be further used for the estimation and selection of a specific location for solar panels. With an average annual potential insolation of 1800 kWh/m² and solar duration of over 2000 h per year for most of its territory, Montenegro is one of the European countries with the highest potential for the development, production, and consumption of solar energy

Quantum Gravity from Noncommutative Spacetime

We review a novel and authentic way to quantize gravity. This novel approach is based on the fact that Einstein gravity can be formulated in terms of a symplectic geometry rather than a Riemannian geometry in the context of emergent gravity. An essential step for emergent gravity is to realize the equivalence principle, the most important property in the theory of gravity (general relativity), from U(1) gauge theory on a symplectic or Poisson manifold. Through the realization of the equivalence principle, which is an intrinsic property in symplectic geometry known as the Darboux theorem or the Moser lemma, one can understand how diffeomorphism symmetry arises from noncommutative U(1) gauge theory; thus, gravity can emerge from the noncommutative electromagnetism, which is also an interacting theory. As a consequence, a background-independent quantum gravity in which the prior existence of any spacetime structure is not a priori assumed but is defined by using the fundamental ingredients in quantum gravity theory can be formulated. This scheme for quantum gravity can be used to resolve many notorious problems in theoretical physics, such as the cosmological constant problem, to understand the nature of dark energy, and to explain why gravity is so weak compared to other forces. In particular, it leads to a remarkable picture of what matter is. A matter field, such as leptons and quarks, simply arises as a stable localized geometry, which is a topological object in the defining algebra (noncommutative $\star$-algebra) of quantum gravity.Comment: 97 pages, to be published in J. Korean Phys. So

Centric diatoms of large rivers and tributaries in Hungary: morphology and biogeographic distribution

Centric diatoms of 107 different Hungarian running waters were investigated. Among them the largest was the River Danube, from which more than one hundred plankton samples were analysed by scanning electron microscopy (SEM). Only one sample was analysed from creeks, which were the smallest running waters analysed in this study. There were also channels with slow currents flowing out of rivers or connecting different rivers.In total, 41 centric taxa belonging to 11 genera were found during this study. The average number of taxa found in a single watercourse was 7, the maximum 40 and the minimum 1. Cyclotella meneghiniana was the most frequently encountered species (present in 60% ofsites). Twelve taxa were found in more than 20% of sites, 7 taxa between 5–10% and 6 taxa only in one site

Relationship Between Atmospheric Circulation and Temperature Extremes in Montenegro in the Period 1951–2010

Previous research conducted in Montenegro suggested an increase in maximum and minimum daily temperatures in the last decades, followed by growth of extreme events frequency. This study examines the relationship between temperature and atmospheric circulation fields in Montenegro using 9 WMO-CCL/CLIVAR extreme climatic indices. The data on atmospheric circulation refers to 11 teleconnection patterns analyzed by seasonal timescales. The assessment of the impact of certain teleconnection patterns has shown a significant connection to extreme events in Montenegro. Calculated results showed the strongest impact of EA, MO, WeMO, EAWR and AO during the winter season, while the weaker impact was calculated for NAO and SCAND. The best impact is obtained for EA and AO during spring, while summer temperature variations are connected to EA, AMO, EAWR, SCAND and NAO. The autumn season showed strong connection with EA, SCAND, AMO, EAWR, MO and AO

Multirhythmicity for a Time-Delayed FitzHugh-Nagumo System with Threshold Nonlinearity

International audienc

Friction memory effect in complex dynamics of earthquake model

In present paper, an effect of delayed frictional healing on complex dynamics of simple model of earthquake nucleation is analyzed, following the commonly accepted assumption that frictional healing represents the main mechanism for fault restrengthening. The studied model represents a generalization of Burridge-Knopoff single-block model with Dieterich-Ruina's rate and state dependent friction law. The time-dependent character of the frictional healing process is modeled by introducing time delay tau in the friction term. Standard local bifurcation analysis of the obtained delay-differential equations demonstrates that the observed model exhibits Ruelle-Takens-Newhouse route to chaos. Domain in parameters space where the solutions are stable for all values of time delay is determined by applying the Rouch, theorem. The obtained results are corroborated by Fourier power spectra and largest Lyapunov exponents techniques. In contrast to previous research, the performed analysis reveals that even the small perturbations of the control parameters could lead to deterministic chaos, and, thus, to instabilities and earthquakes. The obtained results further imply the necessity of taking into account this delayed character of frictional healing, which renders complex behavior of the model, already captured in the case of more than one block