Simulators for Designing Energy-Efficient Power Supplies Based on Solar Panels

Boosted interest in highly efficient power supplies based on renewables requires involving simulators during both the designing stage and the testing one. It is especially relevant for the power supplies that operate in the harsh environmental conditions of northern territories and alike. Modern solar panels based on polycrystalline Si and GaAs possess relatively high efficiency and energy output. To save designing time and cost, system developers use simulators for the solar panels coupled with the power converters that stabilize the output parameters and ensure the proper output power quality to supply autonomous objects: namely, private houses, small-power (up to 10 kW) industrial buildings, submersible pumps, and other equipment. It is crucial for the simulator to provide a valid solar panel I-V curve in various modes and under different ambient conditions: namely, the consumed power rating, temperature, solar irradiation, etc. This paper considers a solar panel simulator topology representing one of the state-of-the-art solutions. This solution is based on principles of classical control theory involving a pulse buck converter as an object of control. A mathematical model of the converter was developed. Its realization in MATLAB/Simulink confirmed the adequacy and applicability of both discrete and continuous forms of the model during the design stage. Families of I-V curves for a commercially available solar panel within the temperature range from -40 to +25 °C were simulated on the model. A prototype of the designed simulator has shown its correspondence to the model in Simulink. The developed simulator allows providing a full-scale simulation of solar panels in various operating modes with the maximum value of the open circuit voltage 60 V and that of the short circuit current 60 A. Issues of statistical processing of experimental data and cognitive visualization of the obtained curves involving the cognitive graphic tool 2-simplex have also been considered within the framework of this research. The simulator designed may serve as a basis for developing a product line of energy-efficient power supplies for autonomous objects based on renewables, including those operating in northern territories

The use of early pottery by hunter-gatherers of the Eastern European forest-steppe

The Eastern European steppe and forest-steppe is a key region for understanding the emergence of pottery in Europe. The vast region encompasses the basins of two major waterways, the Don and the Volga rivers, and was occupied by hunter-gatherer-fisher communities attracted to highly productive forest/aquatic ecotones. The precise dates for the inception of pottery production in this region and the function of pottery is unknown, but such information is vital for charting the pan-Eurasian dispersal of pottery technology and whether there were common motivations for its adoption. To investigate, we conducted AMS dating, including a re-evaluation of legacy radiocarbon dates together with organic residue analysis and microscopy. The dating programme was able to clarify the sequence and show that hunter-gatherer pottery production was unlikely in this region before the 6th millennium BC. Regarding use, stable isotope and molecular analysis of 160 pottery samples from 35 sites across the region shows that terrestrial animal carcass fats were preferentially processed in pots at Middle Volga sites whereas aquatic resources dominate the residues in pottery from the Middle and Upper Don basin. This is supported by fragments of fish, legumes and grasses in the available charred deposits adhering to the inside of pottery from the Don basin. Since the sites from both river basins had similar environmental settings and were broadly contemporaneous, it is posited that pottery use was under strong cultural control, recognisable as separate sub-regional culinary traditions. The ‘aquatic hypothesis’, previously suggested to explain the emergence of Eurasian pottery, cannot be substantiated in this context

The transmission of pottery technology among prehistoric European hunter-gatherers

Human history has been shaped by global dispersals of technologies, although understanding of what enabled these processes is limited. Here, we explore the behavioural mechanisms that led to the emergence of pottery among hunter-gatherer communities in Europe during the mid-Holocene. Through radiocarbon dating, we propose this dispersal occurred at a far faster rate than previously thought. Chemical characterization of organic residues shows that European hunter-gatherer pottery had a function structured around regional culinary practices rather than environmental factors. Analysis of the forms, decoration and technological choices suggests that knowledge of pottery spread through a process of cultural transmission. We demonstrate a correlation between the physical properties of pots and how they were used, reflecting social traditions inherited by successive generations of hunter-gatherers. Taken together the evidence supports kinship-driven, super-regional communication networks that existed long before other major innovations such as agriculture, writing, urbanism or metallurgy

Chronology of Neolithic sites in the forest-steppe area of the Don River

The first ceramic complexes appeared in the forest-steppe and forest zones of Eastern Europe at the end of the 7th–5th millennium BC. They existed until the first half of the 5th millennium BC in the Don River basin. All these first ceramic traditions had common features and also local particularities. Regional cultures, distinguished nowadays on the basis of these local particularities, include the Karamyshevskaya and Middle Don cultures, as well pottery of a new type found at sites on the Middle Don River (Cherkasskaya 3 and Cherkasskaya 5 sites)

Kronologija neolitskih najdišč na območju gozdne stepe ob reki Don

The first ceramic complexes appeared in the forest-steppe and forest zones of Eastern Europe at the end of the 7th–5th millennium BC. They existed until the first half of the 5th millennium BC in the Don River basin. All these first ceramic traditions had common features and also local particularities. Regional cultures, distinguished nowadays on the basis of these local particularities, include the Karamyshevskaya and Middle Don cultures, as well pottery of a new type found at sites on the Middle Don River (Cherkasskaya 3 and Cherkasskaya 5 sites).Prvi keramični kompleksi so se na območju gozdne stepe in gozdov v vzhodni Evropi po­javili na koncu 7. do 5. tisočletja pr. n. št. V dolini reke Don so se ti kompleksi obdržali do prve po­lo­vice 5. tisočletja pr. n. št. Vse te prvotne keramične tradicije imajo skupne značilnosti, pa tudi lo­kal­ne posebnosti. Med regionalne kulture, ki jih danes ločimo na podlagi teh lokalnih posebnosti, uvr­šča­mo kulturo Karamyshevskaya in kulture na območju srednjega toka reke Don, kakor tudi lon­če­nino novega tipa, ki je bila odkrita na najdiščih Cherkasskaya 3 in Cherkasskaya 5