In this paper the basic methodology of the coupled response-degradation modelling of stochastic dynamical systems is presented along with the effective analysis of selected problems. First, the general formulation of the problems of stochastic dynamics coupled with the evolution of deterioration process is given. Then some specific degrading oscillatory systems under random excitation are analyzed with a special attention on the systems with fatigue-induced stiffness degradation. Both, the general discussion and the analysis of selected exemplary problems indicate how the reliability of deteriorating stochastic dynamical systems can be assessed.
Twenty six specimens of the polychaete Eulalia picta were found in finegrained sand tubes. Material was collected in the Antarctic fjord, Admiralty Bay at the depth of about 100 m. The comparison of tube sediment with the sediment composition at the collection site demonstrated that tubes were created with a high degree of particle selection. Our findings might suggest presence of the tube-building behavior in E. picta or show that this species is a highly specialized predator crawling into the tubes of other sessile polychaetes and uses their tubes as protective cases.
Analiza badawcza periodyka „Duchowość w P olsce” pod kątem zawartych w nim aktualnych nurtów i perspektyw teologii duchowości w P olsce pozwoliła na wyciągnięcie następujących wniosków. Teologia duchowości, stanowiąca samodzielną uporządkowaną metodologicznie dyscyplinę naukową, ma duże znaczenie dla teologii, zwłaszcza gdy idzie o połączenie spekulatywnej i przeżyciowej strony życia duchowego człowieka. Ponadto skupia wokół siebie wiele wymiarów duchowości i dziedzin pokrewnych. Stanowi fundament dla duchowości kapłańskiej, małżeńskiej, zakonnej, laikatu. Jest punktem odniesienia dla mistyki, antropologii czy historii duchowości. Z tego też względu wymaga nieustannego doprecyzowywania metodologii nauk. Wśród aktualnych jej nurtów i perspektyw należy wymienić: personalistyczno-chrystologiczną koncepcję duchowości Jana Pawła II , stanowiącej paradygmat teologii duchowości w P olsce, oraz nurt chrystoformiczno-eklezjalny w służbie formacji do kapłaństwa i życia konsekrowanego. Do perspektyw natomiast należy udział teologii duchowości we właściwym sprecyzowaniu duchowości zrzeszeń chrześcijańskich i ruchów charyzmatycznych oraz ich miejsca i znaczenia we wspólnocie Kościoła.
This article presents the use of a multi-criterion Analytic Hierarchy Process (AHP) method to assess geological and mining condition nuisance in longwall mining operations in selected coal mines in Poland. For this purpose, a methodology has been developed which was used to calculate the operational nuisance indicator (WUe) in relation to the cost of mining coal in individual longwalls. Components of the aggregate operational nuisance indicator include four sub-indicators: the natural hazards indicator (UZN), an indicator describing the seam parameters (UPZ), an indicator describing the technical parameters (UT) and an environmental impact indicator (UŚ). In total, the impact of 28 different criteria, which formed particular components of the nuisance indicators were analysed. In total 471 longwalls in 11 coal mines were analysed, including 277 longwalls that were mined in the period of 2011 to 2016 and 194 longwalls scheduled for exploitation in the years 2017 to 2021. Correlation analysis was used to evaluate the relationships between nuisance and the operating costs of longwalls. The analysis revealed a strong correlation between the level of nuisance and the operating costs of the longwalls under study. The design of the longwall schedule should therefore also take into account the nuisance arising from the geological and mining conditions of the operations. Selective operations management allows for the optimization of costs for mining in underground mines using the longwall system. This knowledge can also be used to reduce the total operating costs of mines as a result of abandoning the mining operations in entire longwalls or portions of longwalls that may be permanently unprofitable. Currently, underground mines do not employ this optimization method, which even more emphasizes the need for popularizing this approach.
Poland is now faced with the task of developing a long-term energy policy for decades to come, a strategy capable of reconciling the security of power supplies as well as effective economic processes, ensuring adequate standards of environmental protection. The process in which fossil fuels are converted into energy carriers of choice is accompanied by the emission of various gas substances which escape into the environment. Later on, those substances accumulate in the atmosphere as greenhouse gases affecting the Earth’s radiation balance – the greenhouse effect. Upsetting the balance between emission levels of those gases and the capacity to convert them in the atmosphere is the reason for climate changes. Sustainable development indices constitute a monitoring tool which makes it possible to create a statistical image of a country from the perspective of a new development paradigm. The most important feature of this index is the capability of comparing values, enabling to determine the position of a given object with reference to other objects. The article analyses 8 indexes of sustainable development in terms of using biomass for power generation purposes. The analysis was performed to include three social order indices, two economic indices and one environmental order index. It was concluded that the use of biomass in power generation can reduce the emission of greenhouse gasses significantly at several stages: the emission can be eliminated from the biological process of biomass conversion, storage and it can also be reduced during transportation.