For Plato, language was the way to cognize the universe. The philosophy of language, which was primarily initiated by Plato in the Cratylus, still has not received answers to the questions settled by this great Greek thinker. In fact, it just offered various solutions formed in different conceptions and approaches in the ancient, scholastic, modern and postmodern periods. The questions raised by Plato in his dialogue have been continued in various nativistic theories of language, especially in works of Noam Chomsky. Language—as it is seen by Plato, i.e., as uniting our inner world with the outer world, is a significant feature of humankind, is still underinvestigated.

Like other harbour cities in Europe, Lisbon has an axial development anchored in pre-existing confi gurations which dot from east, more industrial areas, to the west, a more monumental and urban type. The diversity of fabrics and the overlapping of various time layers become decoded through a functional specialization infrastructural line, which, from rural, becomes increasingly infrastructured as part of the on-going reinvention of the city of Lisbon.

The article presents the author’s considerations on the significance of the investment package diversifying natural gas supplies as part of the Northern Gate in ensuring Poland’s energy security. Data found in literature concerning the possibilities of importing the raw material by sea (terminals, gas pipelines) includes investments at various stages of concept development and construction. However, these documents lack cohesive information about a full investment package being implemented. The author has thus attempted at creating variants concerning the diversification capacities of the Republic of Poland in reference to several key offshore and onshore projects. A problem has therefore been formulated: To what extend will the Northern Gate investment package increase Poland’s energy security as a result of increased supply of natural gas from the sea? To answer this questions, researchers were forced to verify their working hypothesis which assumed that Northern Gate investments including a comprehensive package of projects had the potential of significantly improving the level of energy security in Poland by extending the possibility of importing natural gas. To solve the problem and verify the hypothesis, the researchers applied systemic analysis, deduction and variant analysis, which were used to estimate the possible import capacities of the raw material by sea. As a result of the works, the researchers created four variants including various investment projects assuming the import of 7.75 m3 to 30,95 B m3 of natural gas a year by sea. The variant which was adopted as the most probable indicates the possibility of importing 17.75 through 22.75 B m3 of gas a year, which is 111% of the average annual demand in Poland.

In the presented paper we discuss pure versions of pushdown automata that have no extra non-input symbols. More specifically, we study pure multi-pushdown automata, which have several pushdown lists. We restrict these automata by the total orders defined over their pushdowns or alphabets and determine the accepting power of the automata restricted in this way. Moreover, we explain the significance of the achieved results and relate them to some other results in the automata theory.

Inflation targeting is nowadays used by around 40 countries, with each of them tailoring some features of the strategy to its own needs. This holdse specially for deciding on the level of inflation targets. The analysis conducted in the paper aims at identifying factors affecting the choice of the target levels, with macroeconomic, structural and institutional characteristics of the reviewed economies being investigated. The main conclusion is that both backward- and forward-looking models can help to explain how inflation targets are set. Evidently inflation and GDP growth (past and forecast) together within formation on a possibly on going disinflation process are of key importance,but – especially for emerging market economies – also inflation variance and the level of economic development seem to influence the target levels. Moreover,many of the institutional features related, among others, to transparency and accountability of the reviewed central banks, were found significant in the analysis.

This paper proposes a generalized fractional controller for integer order systems with time delay. The fractional controller structure is so adopted to have a combined effect of fractional filter and Smith predictor. Interestingly, the resulting novel controller can be decomposed into fractional filter cascaded with an integer order PID controller. The method is applied to two practical examples i.e. liquid level system and Shell control fractionator system. The closed- loop responses resulting from the proposed method are compared with that of the available methods in the literature. For quantitative evaluations of the proposed method, Integral Absolute Error (IAE) and Integral Square Control Input (ISCI) performance criteria are employed. The proposed method effectively enhances the closed-loop response by improving the IAE values, reducing the control effort inputs to achieve the desired output. The disturbance rejection and robustness tests are also carried out. The robustness test reveals a significant improvement in the maximum absolute sensitivity measure. That is displayed in numerical simulations of the paper.

Subnetwork with two nodes shared with entire ventilation network can be separated as its part. For the network under common ventilation conditions, one of these nodes will become the subnetwork starting node, while the other will be the subnetwork end node. According to the graphs theory, such a piece of the network can be considered as a subgraph of the graph representing the entire ventilation network. A special feature of that subgraph is lack of predecessors of the subnetwork starting node and lack of successors of the subnetwork end node. Ventilation district of a mine may be often treated as a subnetwork. Vicinity is a part of the network which is not separated as subnetwork. In the case of a ventilation district its vicinity forces air flow through the district. The alternative characteristic curve of the vicinity can therefore be compared to the characteristics curve of a fictional fan that forces the airflow in the district.

The alternative characteristics (later in the text: the characteristics) of the vicinity of the ventilation district in an underground mine strongly influence air quantity and therefore play a crucial role in the reduction of methane, fire and thermal hazards. The role of these characteristics and proper selection of their approximating function were presented in the article.

The reduction of resistance of an intake stopping (having influence on entire resistance of a ventilation district) produces increased airflow in the district. This changes of airflow in the district caused by a variation in internal resistance (e.g. by opening an internal regulation stopping) depends on the characteristic of the vicinity of the district. Proper selection of its approximating function is also important for this matter.

The methods of determination of the alternative characteristic curve of the district vicinity are presented. From these procedures it was possible to obtain the results of air quantities and differences in isentropic potentials between an inlet and an outlet to/from the ventilation district. Following this, the characteristics were determined by graphic and analytic methods. It was proved that, in contrast to flat vicinity characteristics, steep ones have a smaller influence on the airflow modification in the district (which are caused by a regulation of the district resistance). The characteristic curve of the vicinity determines the ability to regulate air quantity and velocity in the district.

In the world-class Cu-Ag deposits of the Legnica-Głogów Copper District (LGCD), constant bulk density values are adopted to estimate the ore and metal resources within them based on the results of previous studies of the LGCD deposits carried out at the stage of their exploration and documentation: 2.6 Mg/m3 for the carbonate series, 2.5 Mg/m3 for the shale series, and 2.3 Mg/m3 for the sandstone series. The main purpose of research was to analyze the range of possible differences at local scale of observation between constant values of bulk densities (hereinafter referred to as reference values) assigned during deposit documentation to the main lithological units and bulk densities of these units determined based on the results of experimental sampling of individual lithological units within the exploited copper and silver deposits (Lubin, Polkowice-Sieroszowice and Rudna). In general, when it comes to Cu-Ag LGCD deposits (or their large parts), the relative diversity of estimates of average bulk densities of ores based on the results of experimental sampling (more than 1,600 samples from different individual lithological units were collected at 500 sampling points in mining excavations) and reference values is low (with a median not exceeding 3%). The results of studies indicate, however, that the application of reference bulk densities at the local observation scale may result in significant underestimation (up to nearly 20%) or overestimation (up to 11%) of real bulk densities of the main lithological units. This may have a noticeable impact on the correct estimation of ore and metal resources in small parts of deposits and, as a consequence, hinder the reconciliation of the planned and actual ore mining production.

The application of enhanced oil recovery processes (EOR – Enhanced Oil Recovery) on oil fields increases recovery efficiency. This is especially important in depleted and mature fields. This should result in an increase in production by raising the recovery factor (the ratio of oil produced to total geological reserves). This review presents the growing trend of gas injection (particularly carbon dioxide). In Polish oil fields, conventional methods are currently used. This means that much can still be done in this area. The selection of the optimum method for a given field is a complex procedure consisting of many stages, from collecting data about the field, through more advanced data interpretation, to working out a detailed proposal for the most efficient method of extraction. The pre-selection stage involves excluding methods which, owing to their specific mechanisms, cannot be used for a particular field – e.g. thermal methods in light oil fields or nitrogen injection into shallow reservoirs. This paper analyzes the potential for the application of EOR methods in Poland using a binary technical screening method. Forty-nine, mature Polish oil fields were analyzed. Apart from the rock type, other parameters were also taken into account in the analysis as follows: oil density and viscosity, average porosity, permeability and thickness of the reservoir, and also depth of deposit. In regard to the criteria for the EOR methods applied, the subjects of analysis are oil fields with medium density and viscosity and low permeability (double porosity in carbonate rocks), which are at a relatively shallow or medium depth of deposit. The results of analysis show that gas injection methods, especially carbon dioxide or nitrogen, have the highest potential. Application of this method must be preceded by detailed research and field pilot tests. International experience cannot be applied directly to Poland because of different field characteristics as well as technological and economic conditions.

The UK’s decision to leave the EU illustrates some of the tensions embedded in European integration, enabling us to examine how nationalism and cosmopolitanism operate simultaneously, thus reinforcing each other. Furthermore, the prolonged Brexit negotiations have created a climate of protracted insecurity where the only certainty is uncertainty. This is particularly reflected in the migratory experiences of European citizens currently residing in the UK. Academic research has begun exploring the affective impact of Brexit; however, little is known about how processes of connection and disconnection operate simultaneously, nor which coping strategies European migrants have employed to navigate this state of in-betweenness. Using the anthropological notion of liminality as a lens, we draw on participant observation and semi-structured interviews to explore the experiences of Brexit and the coping practices of a range of (new) Bulgarian and (old) Italian European migrants. We argue that Brexit results in a loss of frames of reference for European migrants in the UK – which can be both liberating and unsettling, depending on migrants’ positioning as unequal EU subjects as well as their views on the nature of their future re-incorporation in post-Brexit Britain.