Wood pellets, commonly referred to as biomass fuel, are increasingly used in heating and district heating in the European Union countries, including Poland. Their use in class 5 and/or Ecodesign boilers enables an individual consumer to use energy from renewable sources, reduce the environmental burden by reducing the emission of harmful compounds, and provides a sense of comfort by automating the boiler system. The article presents the current situation in the global wood pellet market, describes the basic quality standards applicable to this fuel during production, and indicates the difficulties in the implementation of programs co-financing the replacement of obsolete coal-fired boilers with automatic class 5 biomass-fired boilers. The research presented in this article is focused on the presence of contaminants in the DIN Plus, EN Plus, and A1 pellets, as well as in non-certified pellets. The analysis has shown that the use of wood pellets containing prohibited substances negatively affects boiler operation and contributes to the formation of slag and the emission of harmful compounds, making the discussed fuel non-ecological.

Admixtures are commonly used nowadays in the mix composition of concrete. These additions affect concrete properties and performance especially creep deformations. This paper shows the effect of admixtures on creep of concrete. In fact, creep deformations have prejudicial consequences on concrete behaviour; an incorrect or inaccurate prediction leads to undesirable consequences in structures. Therefore, an accurate estimation of these deformations is mandatory. Moreover, design codes do not consider admixtures’ effect while predicting creep deformations, thus it is necessary to develop models that predict accurately creep deformations and consider the effect of admixtures. Using a large experimental database coming from international laboratories and research centres, this study aims to update the Eurocode 2 creep model by considering the type and percentage of admixtures using Bayesian Linear Regression method. The effect of two types of admixtures is presented in this paper; the water reducer and silica fume.

A ccording to the Polish Geological and Mining Law the granting of a concession for the exploration of a hydrocarbon deposit and the production of hydrocarbons from a deposit, or a concession for the production of hydrocarbons from a deposit in Poland is proceeded according to a tender procedure or open door procedure (upon a request of an entity). O n June 28, 2018 the Polish Minister of the Environment announced 5 tender areas. These areas (promising for discoveries of conventional and unconventional oil and gas deposits) were selected by the geologists of the Polish Geological Institute-NRI and Department of Geology and Geological Concessions of the Ministry of the Environment based on the geological data resources stored in the National Geological Archive. These are: Bestwina-Czechowice, Królówka, Pyrzyce, Złoczew i Żabowo. The main exploration target on the areas located in central and north-western Poland (Pyrzyce, Żabowo and Złoczew) is related to Permian Rotliegend sandstones and carbonates of the Zechstein/Main Dolomite. The Bestwina-Czechowice and Królówka areas (southern Poland) are prospective for conventional and hybrid-type accumulations of gas in the Miocene of the Carpathian Foredeep below the Carpathian Overthrust and in the Paleozoic-Mesozoic basement. The beginning of the 4th bidding round for hydrocarbon concessions is planned in Q4 2019. The entity can also choose the area and apply for a license submitting an application to the Ministry of the Environment. The area indicated by the entity cannot be the subject of a tender or any other concession, and the maximum acreage is 1,200 km2.

An attempt to summarize the primary iron raw materials and steel market’s hundred years history as well as influence of economic indicators on the iron ore deposit qualification for extraction has been undertaken in the paper. Steel products are crucial to the world economy, and their production has a major impact on the environment. The main factor is the huge scale of the production and growth rate, unprecedented among minerals. Iron ore and concentrates production has increased more than thirty times over the past century, and the geological resource base at the current level of consumption has provided almost 250 years of sufficiency. There have been tremendous changes in the world geography of the ore and steel industry. The iron ore mining industry is the driver of other economic activities (land transport, freight, metallurgy) and involves huge capital and human resources. The consumption of iron raw materials is also considered as an important indicator of the countries development and current or even future economic situation. Population growth remains one of the key stimulating factors. The prices of ore and iron concentrates depend on the quality of the raw material, delivery conditions, market balance and the weight of the ordered cargo. They are usually the subject of negotiations. In the past, they were long-term contracts, while short-term (yearly, quarterly) and current spot transactions are now significant. The prices of ores and concentrates in relation to steel prices are showing a strong correlation. The average iron content of the reserves has been reduced in the largest producers in the 21st century, however it does not translate into the quality of mining output. Exploitation of the richer parts of the mineral deposit is usually carried out. The high content of iron in the output is a response to the technological requirements of the metallurgy where the blast furnace charge should contain at least 56% Fe and 5–8% FeO. The current surplus of geological-mining supply (large resource base) justifies that a mineral deposit choice, destined for excavation, is economic profit maximization as well as social and environmental considerations.

The analytical approach is used for checking the stability of laterally unrestrained bisymmetric beams. The stability equations for simply supported beams are solved approximately using the Bubnov–Galerkin method [4]. The lateral buckling moment depends on bending distribution and on the load height effect. Each of applied concentrated and distributed loads, may have arbitrary direction and optional coordinate for the applied force along the cross section’s height. Derived equations allow for simple, yet fast control of lateral buckling moment estimated by FEM [15].

Public spaces designed in a reasonable way make up an element that heals the city. They are both areas dedicated to collective recreation and a catalyst for social activities. Regarding a rational space exploitation, a reuse of grounds that are being liberated as a result of cities reorganization and revitalization of postindustrial areas should be a clue. The latter represent a unique esthetic virtues due to specificity of their original function. Comparison of the selected designs and scientific approaches had been made in order to take the floor in a debate about devastated areas revitalisation and city – and center-making capability of cultural investments. The importance of psychological links between human and his environment is set down by the presence of features defining the open form in a mentioned projects.

This article examines three aborted publishing projects involving popular science magazines from the early 19th century, two of them in Cracow, one in Kalisz. Their history has been reconstructed thanks to the publishers' prospectuses found in collections of the Jagiellonian Library.