Krajowa energetyka od lat oparta jest na węglu kamiennym i brunatnym. Kilkudziesięcioprocentowy udział elektrowni opalanych węglem kamiennym i brunatnym w strukturze wytwórczej wymusza konieczność zakupu tych paliw do produkcji energii elektrycznej w otoczeniu zmiennych cen surowców, kształtowanych na międzynarodowym rynku. Ceny węgla kamiennego są wypadkową wielu zmiennych i zależą nie tylko od światowej sytuacji geopolitycznej czy ekonomicznej, ale mogą być również skutkiem klęsk żywiołowych. Ceny na rynkach międzynarodowych są ze sobą ściśle powiązane. Szczególnie wysokość cen kształtowanych przez największych producentów i eksporterów (między innymi przez Indonezję, Australię czy Chiny) mają wpływ na ceny surowca na rynku europejskim. Są one także punktem odniesienia dla cen węgla brunatnego na lokalnych rynkach. W niniejszym artykule przeanalizowano wpływ zmienności cen węgla kamiennego na rynkach światowych na zmienność krajowych cen paliw (kosztów zakupu) wykorzystywanych do produkcji energii elektrycznej, cen sprzedaży energii przez jednostki wytwórcze oraz cen energii elektrycznej dla odbiorców końcowych. Sprawdzono także czy zmienność cen węgla kamiennego ma wpływ na zmienność cen energii dla przedsiębiorstw przyłączonych do sieci na parametrach wysokiego napięcia i dla gospodarstw domowych. Dodatkowo zbadano także korelację pomiędzy analizowanymi parami zmiennych. Niniejszą analizę wpływu wybranych zmiennych przeprowadzono przy użyciu podstawowych miar statystycznych. W drugiej części badań przeprowadzona zostanie poszerzona analiza wzajemnego wpływu (przyczynowości) zmiany analizowanych parametrów z wykorzystaniem zaawansowanych narzędzi statystycznych.

The paper presents the results of research aimed at developing assumptions for the preparation of a charge in the form of fine scrap copper alloys (chips/shells) guaranteeing effective removal of impurities and obtaining a metal bath of the required metallurgical quality. The tests were conducted for tin-zinc-lead bronze of the CC499K grade. As part of the work, the characteristics of this type of waste available on the market were made in terms of quality and the possibility of their use for the production of both alloys and finished products, taking into account the elimination of harmful impurities that may ultimately affect the production process adversely.
The subject of the work was the selection of appropriate waste cleaning methods in the form of an oily shell in the CC499K (CuZn5Sn5Pb2) grade and its drying in terms of increasing the use of impure waste from machining as scrap for direct melting. The waste was assessed in relation to individual parametres. The research was carried out on 3 groups of waste, with varying degrees of moisture.

Reasoning with limited computational resources (such as time or memory) is an important problem, in particular in knowledge-intensive embedded systems. Classical logic is usually considered inappropriate for this purpose as no guarantees regarding deadlines can be made. One of the more interesting approaches to address this problem is built around the concept of

active logics. Although a step in the right direction, active logics are just a preliminary attempt towards finding an acceptable solution. Our work is based on the assumption that labelled deductive systems (LDSs) offer appropriate metamathematical methodology to study the problem. As a first step, we have reformulated a pair of active logics systems, namely the memory model and its formalized simplification, the step logic, as LDSs. This paper presents our motivation behind this project, followed by an overview of the investigations on meta-reasoning relevant to this work, and introduces in some reasonable detail the MM system.

The article presents tests on a new lead-free bronze CuSn4Zn2PS, intended for fittings for contact with drinking water, in which the addition of lead was replaced with sulphur. The subject of the experimental work was the production of semi-finished products from this alloy based on the charge coming entirely from waste generated after machining. A specialized pilot line was used for the tests, and after cleaning, the waste was melted and then were continuously cast in the form of rods and hollow rods. The cleaning efficiency was assessed, and the manufactured semi-finished products were subjected to tests, including the assessment of the chemical and mechanical homogeneity and the structure of the test batch of the semi-finished casting products in terms of the possibility of manufacturing products meeting the requirements of technical specifications. The obtained results, both in terms of a stable chemical composition, homogeneous and reproducible mechanical properties, fully compliant with the specifications for fittings bronzes (CC499K), as well as the lack of faults of the obtained semi-finished products, despite a very large share of waste material, indicate the possibility of using the tested recycling method for the production of semi-products of sulphur bronze, which is an alloy that is relatively difficult to manufacture.

Economic development is strictly dependent on access to inexpensive and reliable energy sources based on diversified primary fuels. The strategic framework for the construction of the energy mix is defined in the Energy Policy of the State, the content of which, in terms of its mandatory elements, has been specified in the Energy Law. The task of the Energy Policy of the State is to create the shape of the future power sector, including designing the most advantageous regulatory, system and technical solutions guaranteeing the appropriate level of energy security of the country, monitoring of the system’s evolution and also designing and implementing changes aimed at the optimization of the functioning mechanisms. The vision of the development of the power system at the global level should also reflect changes in the formation of dispersed civil energy structures. Unfortunately, the results of the conducted analyses reveal existing imperfections of the data acquisition and information system, which should be used in the planning process. This issue is particularly important from the perspective of the dynamically developing concept of the energy self-sufficiency of communes and the emergence of energy clusters. The present paper describes the functioning of strategic planning in the field of the electric power system with an illustration of the improperly functioning mechanisms of information transfer in the context of the advancement of dispersed civil energy structures.