All the restructuring programs that have been implemented in Polish bituminous coal mining as a primary way to reduce mining costs relied on the increased concentration of mining operations. Those efforts especially involved a significant simplification of existing or newly developed structures for accessing or cutting the deposits intended for extraction; implementation of advanced mining technologies, and upgrading of machines used in mine faces. However, in order for these to deliver the expected results, it is important to organize mining operations in such a way so that those advanced, and usually very expensive, mining-related fixed assets – machinery and equipment – are used sensibly. In order to define a reasonable production capacity of each longwall face, it is necessary to apply various criteria related to the mining and technical aspects, occupational safety, and organizational and economic aspects. Only then will it be possible to evaluate the expected effects in the field of concentration of mining in a mining company and in the mines which form part of such enterprises. Decisions in this respect should always be made at the planning stage, based on analysis results. The aim of this article is to explore the factors involved in concentration-related decision-making in mining companies, including the underlying mining/technical, organizational, and economic/ /financial aspects. A mining company is understood as a group of related mines, the primary business operations of which include bituminous coal mining, processing, and trading.
226 papers by Polish authors and co-authors have been collected. They deal with Antarctic or sub-Antarctic fishes and also their parasites. The majority (35.7%) of the publications discuss fish biology including growth, age, maturity, feeding and occurrence of particular species in the area. Fewer papers are devoted to parasitology (26.0%). Papers dealing with fish biomass and exploitation make up 18.5%. Papers dealing with morphology and systematics make up 6.6%. The remaining papers are devoted to technology, physiology, palaeontology and others.
The article has presented the assumptions underlying the organization of emissions trading of greenhouse gases with a particular emphasis on CO2 emission allowances. Through the analysis of the literature, international activities were undertaken aimed at reducing greenhouse gas emissions into the atmosphere, starting from the First World Climate Conference organized in 1979. The origins and guidelines of the Kyoto Protocol were also given considerable attention. In addition to the description of the key assumptions of the Protocol and its main components, the characteristics of international trade in Kyoto units were also included. The mechanisms involved in international trade and the types of units traded in a detailed manner are described. In the next part of the article, emission trading systems operating in the world are characterized. In the second part of the paper special attention was paid to the conditionings of the European market, i.e. European Emissions Trading System – EU ETS. Historical events were presented that gave rise to the creation of the EU ETS. In the next steps, the types of units that are tradable were described. Furthermore, the trade commodity exchanges on which trade is conducted, the key factors determining the price of individual allowances are also indicated. In the last part of the article, relatively recent issues – the IED Directive and the BAT conclusions have been pointed out. Referring to the applicable regulations, the impact of their implementation on the situation of entities obliged to limit greenhouse gas emissions was analyzed. In the final phase, an attempt was made to assess the impact of IED and BAT to electricity prices.
Analysis of the state of-the-art in research of minichannel heat exchangers, especially on the topic of flow maldistribution in multiple channels, has been accomplished. Studies on minichannel plate heat exchanger with 51 parallel minichannels with four hydraulic diameters, i.e., 461 μm, 574 μm, 667 μm, and 750 μm have been presented. Flow at the instance of filling the microchannel with water at low flow rates has been visualized. The pressure drop characteristics for single minichannel plate have been presented along with the channels blockage, which occurred in several cases. The impact of the mass flow rate and channels’ cross-section dimensions on the flow maldistribution were illustrated.
Issues related to the small arms used in the January Uprising (1863-64) are as much interesting as they are complex. On the one hand, we have a considerable number of sources, including numerous reports and recollections of participants in the battles, photographs of insurgents in full gear, official documents (both Polish and Russian), and finally authentic exhibits collected in museums. On the other, the determination of the number of weapons in which Polish troops were equipped during the almost 18 months long war, as well as the concrete models of the arms, is an extremely difficult task. This question has so far been largely treated in general terms. Historians writing about the 1863-64 uprising focused their attention on the issues to do with the organisation of the purchase of weapons (devoting a lot of space to its fi nancing), as well as the amount of war material brought to Congress Poland. Normally, information on concrete types and models was omitted, which is partly understandable, since the Polish historiography concerning the 19th century military techniques remains almost virgin ground. Th is article attempts to summarise the available knowledge, show the armament issue in a broader context (“competition” in the European arms market), and determine the most important models of handguns and guns (i.e. those which were most frequently used in the insurgent army) on the basis of written, iconographic, and archaeological sources.
Patients with coronary chronic total occlusions have usually anginal symptoms, reversible ischemia on stress testing and viable myocardium subtended by the occluded artery. Notwithstanding the optimal clinical characteristics for revascularization by means of percutaneous coronary intervention, the majority of subjects with chronic total occlusions are treated medically or referred for coronary artery bypass grafting. This review highlights the evolution and latest advancements in percutaneous techniques and technologies for revascularization of CTO.