In this paper the general solution of nonlinear satellite pseudorange equation system has been given. This solution was obtained by the application of the new positional transformation determining relations between the points in three-dimension space. It has been proved that computation of the position does not require knowledge of the light speed, occuring in pseudorange measurements, or determination of approximate coordinates. The general solution allows one to obtain all possible solutions including complex conjugate positions. This work has also stated that there exists some space regions in which it is not possible to determine the positions in the domain of real numbers. This is especially important in navigation of objects moving in the space.

Fallow wasteland, seemingly worthless for agriculture, may in fact be of great natural value. We need to be very cautious when using it for cultivating energy plants.

Pozornie bezwartościowe dla rolnictwa nieużytki rolne są niezwykle cenne przyrodniczo. Przeznaczaniu ich pod uprawę roślin energetycznych musi towarzyszyć wielka ostrożność.

There are many IT tools available on the market that carry out various types of forecasts in the gas industry. Programming evolves with the availability and capability of computers. IT tools support the user in engineering calculations, but also present the obtained results in an interesting visualization, e.g. in the form of interactive charts. The software can support making business decisions, which, in turn, can be used as business intelligence. In the era of digitization, huge metadata of measurements are created, so conducting data analyzes in the energy sector is very common. Moreover, rapidly evolving artificial intelligence creates new opportunities. The article presents a sample analysis of calculations using RStudio, an integrated development environment for the R language, a programming language for statistical calculations and graphics. The aim of the article is to present the possibility of using R language software to make a forecast and to determine the quality of forecasts. The article aims to present the possibility of making forecasts based on mathematical models available in R packages and the possibilities offered by the forecasting platform to readers. The article presents the U.S. market and has a particular focus on Natural Gas Residential Consumption in Pennsylvania (publicly available data from the U.S. Energy Information Administration). This dataset represents the monthly consumption of natural gas between 2015 and 2020. Forecasts were presented over a span of 12 months.

The natural gas supply is used from Russia Federation as a political instrument in the geopolitical and territorial conflict with Ukraine. The effectiveness of Russian strategy towards Ukraine is due to the fact that power in Kiev is also exercised by the pro-Russian politicians and supported on the part of Ukrainian oligarchs. The two countries are interdependent in terms of energy by means of the existing gas infrastructure and long-term contracts, because Ukraine guarantees the Russian Federation the transit of natural gas to Europe through its system of transmission gas pipelines, and Russia pays for the transit and used to supply the agreed amount of gas to Ukraine. For the first time – in 2016 – Ukraine didn’t import natural gas directly from the Russia Federation. This article attempts to obtain an answer to the research question, whether Ukraine actually strives to diversify its natural gas supply. What part of this policy is the Ukrainian political instrument in terms of Russia, and what part is the real political objective? Especially in the context of the gas contract between both States, ending in 2019. What role will be played the underground gas storage in the geopolitical struggle? Despite Nord Stream II the Russian Federation still needs the Ukrainian pipelines to fulfill contractual obligations in gas supplies to Europe. What are the strategic goals of the energy policy of Ukraine and Russia? The geopolitical as well as geo-economic theories will be applied. Moreover, a factor analysis as well as a decision-making analysis will be used. The political analysis method and the forecasting technique are applied to obtain, not only theoretical, but also practical input.

The paper presents an analysis of energy and economic effectiveness of the combined heat and power (cogeneration) technologies fired with natural gas that may be deemed prospective for the Polish electric power system. The current state of the cogeneration technologies fired with natural gas in Poland is presented. Five cogeneration technologies fired with natural gas, prospective from the point of view of the Polish electric power system, were selected for the analysis. Namely, the paper discusses: gas-steam combined heat and power (CHP) unit with 3-pressure heat recovery generator (HRSG) and steam interstage reheat, gas-steam CHP unit with 2-pressure HRSG, gas-steam CHP unit with 1-pressure HRSG, gas CHP unit with small scale gas turbine, operating in a simple cycle and gas CHP unit with gas engine. The following quantities characterizing the energy effectiveness of the cogeneration technologies were selected for the analysis: electricity generation efficiency, heat generation efficiency, primary energy savings (PES) and CO2 unit emission. The economic effectiveness of particular technologies was determined based on unit electricity generation costs, discounted for 2019, including the costs of purchasing CO2 emission allowances. The results of calculations and analyses are presented in a table and on a figures.

The article aims to study the determinants of the energy policy implementation process from

risks and danger perspectives by building the risk management system model. The research methodology

is based on the application of the risk map to the energy policy. Our results confirmed

that the risk map could be applied in the energy industry to identify the risks and to implement the

energy policy risk management system model which will prevent critical uncertainties and risk

structure, identified from the risk map as well as bring the energy industry to the future state by

implementing scenarios and strategies, developed by the World Energy Council. The research limitations

are that the main limits are concerned with the lack of the evaluation results of the energy

policy risks aimed for the system management of the changes which these risks may introduce. No

empirical study has been conducted. The application of the risk map is related in a major part to

the enterprise level with financial and technical purposes of changes. In the research we made an

attempt to develop the managerial recommendations for the regulators on how to make a transitions

of risks to opportunities of introducing and managing changes in the framework of the energy

policy risk management system model. The originality/ value of the paper consists firstly, in the innovativeness

of applying the tool of matrix forecasting to the energy sector; secondly, in providing

a supporting tool to policy-makers and managers decisions.

This article discusses the issue of hypermodernity, which was studied as part of the research project Poles in the World of Late Capitalism. The article presents biographical models of hypermodernity and strategies of coping with hypermodern ideology, that is, cyclothymias, conversions, and hypermodern episodes.

The structural system of a multiple strip-shaped pillar-roof is common in underground mine exploitation, and research on its mechanics and micro/macroeconomics is meaningful for utilizing strip-shaped pillar resources. A general model of the structural system of a multiple strip-shaped pillar-roof was established, the deformation mechanism of the model was analysed by material mechanics, and the deflection curve equations of the model were obtained. Based on the stress strain constitutive relation of the strip pillar and cusp catastrophe theory, the nonlinear dynamic instability mechanism of the structural system of a multiple strip-shaped pillar-roof was analysed, and the expressions of the pillar width for maintaining the stability of different types of structural systems were derived. The benefits of different structural systems were calculated using micro/macroeconomic theory, the type of the structural system was determined, and different recovery schemes were obtained. Theoretical application research was applied to a large manganese mine, and the results demonstrate that no pillar recovery was needed in 2016, a 9-m wide artificial pillar could be built to replace a pillar in 2017, and the construction of 14-m wide artificial pillars can be conducted in 2018.

Feldspar is a basic requirement for glass, ceramics, and other industries. The presence of iron in feldspar is one of the challenging aspects of feldspar processing. To improve the quality of feldspar for use in various industries, dry magnetic separation is one of the best techniques for reducing iron in feldspar, especially in arid regions to overcome the common problem of lack of water resources as well as to reduce the operational cost of the enrichment process. Therefore, dry magnetic separation experiments were carried out to remove the iron content from feldspar ore in the Wadi Umm Harjal area in Egypt to meet the specifications required for different industries. The sample was analysed using XRD, XRF, and optical microscopy, which revealed that it is a mixture of potassium feldspar (microcline/orthoclase), albite, and quartz in the presence of hematite mineral serving as the main iron impurities in addition to the free silica content. The effect of parameters on the activity of the dry high magnetic separators was investigated in addition to cleaning the products. The iron oxide reduced from 0.69% in the head sample to 0.08% after dry high-intensity magnetic separation, and the whiteness increased from 82.01% in the head sample to 95.97% in the separated concentrate. The experimental results showed that there is a possibility to obtain feldspar concentrates with low content of Fe2O3 from the area where according to the results, approximately 88.4% of iron was removed from the head sample.

Securing the certainty of supplies of the necessary minimum energy in each country is a basic condition for the energy security of the state and its citizens. The concept of energy security combines several aspects at the same time, as it can be considered in terms of the availability of own energy resources, it concerns technical aspects related to technical infrastructure, as well as political aspects related to the management and diversification of energy supplies. Another aspect of the issue of energy security is the environmental perspective, which is now becoming a priority in the light of the adopted objectives of the European Union’s energy policy. The restrictive requirements for reducing greenhouse gas emissions and increasing the required level of renewable energy sources in the energy balance of the Member States is becoming a challenge for economies that use fossil fuels to a large extent in the raw material structure, including Poland. Poland is the largest producer of hard coal in the European Union and hard coal is a strategic raw material as it satisfies about 50% of the country’s energy demand. In this context, the main goal of the article was to determine the future sale of hard coal by 2030 in relation to environmental regulations introduced in the energy sector. For this purpose, a mathematical model with a 95% confidence interval was developed using artificial LSTM neural networks, which belong to deep learning machine learning techniques, which reflects the key relationships between hard coal mining and the assumptions adopted in the National Energy and Climate Plan for the years 2021–2030 (NECP).

In our paper we discuss the development of analytical/periphrastic structures in Spa-nish such as the periphrastic passive voice, the periphrastic comparison of the adjec-tictive, and the periphrastic future tense. Moreover, we discuss the process of phonetic attrition within the noun paradigm and the development of the SVO word order from the SOV one. We take into consideration a stretch of time that starts in the pre-Proto-Indoeuropean period and ends in the period of Modern Spanish. One of our conclu-sions is that the development of analytical structures is part of a cyclical process.

Dynamic changes and the increasing diversity of migrant societies support small-scale enclave businesses in Poland. Female migrants from Belarus and Ukraine appear to have found their niche in the beauty and cosmetology sector. Nevertheless, their entrepreneurship goes beyond the enclave market. Specialists provide services to migrant communities and simultaneously target Polish clients to ensure the success of their ventures. This article presents the results of qualitative research based on 13 in-depth interviews with Ukrainian and Belarusian beauty specialists. I focus on these businesswomen’s narratives about their entrepreneurial trajectories. My aim is to explore how they use and extend their social relationships in order to acquire entrepreneurial agency. Entrepreneurship can be understood as a socially embedded practice. I apply an intersectionality approach to investigate the complexity of socially constructed identities and the dimensions of individual entrepreneurial agency. Incorporating a mixed embeddedness approach, I examine the impact of structural factors on entrepreneurial activity and the importance of social networks for women’s self-realisation as independent beauty specialists.

This article focuses on the interrelationship between homeland and diaspora at times of crisis. It adopts a comparative lens to look into diasporic (dis)engagement with the homeland, specifically analysing the cases of Greece and Ukraine. The main research issues are how crises affect the engagement between homeland and diaspora – taking Greece and Ukraine as case studies – and which the defining contextual factors are that transform the diaspora engagement. The article unpacks the homeland–diaspora nexus concerning two states with different socio-political backgrounds, both going through severe political and economic crises. In so doing, the article gives prominence to the differentiation between the en-gagement of the two different diasporas with their home countries at times of crisis. Evidence suggests substantial engagement in the Ukrainian case while, in the Greek case, a more mixed attitude – leaning towards disengagement – is apparent.

Drawing on extensive qualitative research into experiences of migration and settlement among Central and East European (CEE) migrants living in Scotland, this article examines the role of intersecting emotional and material (in)securities in migrant families’ decision-making regarding and experiences of longer-term settlement. The article queries fixed or given understandings of either ‘family’ or ‘secu-rity’ and explores the complex and sometimes contradictory relationship between them. In so doing, it makes a number of significant and interconnected theoretical and empirical contributions to existing research in the field of family migration. Through a critical analysis of the relationship between family and (in)security the article offers nuanced insight into the ways in which family processes of reunion, separation and (re)formation link to decisions regarding migration and settlement. The intersecting and sometimes contradictory forms of emotional and material support, obligation and vulnerability which both family relations and processes of migration and settlement entail are critically analysed by bring-ing together theoretical frameworks of social (in)security and understandings of family as ‘made’ rather than ‘given’. Finally, attention given to the temporal aspects of (in)security, as well as the transnational aspects of migrants’ lives, provides new ways of understanding the open-endedness of decision-making processes relating to migration and settlement, especially where these involve multiple decision-makers.

Our article considers social remittances and social change in Central and Eastern Europe. We show how migration scholarship can be embedded into the wider study of social processes and relations. ‘Social remitting’ sometimes seems to be little more than a slippery catchphrase; however, this article defends the concept. If it is defined carefully and used cautiously, it should help the researcher to think about what, in addition to money, is sent from one society to another and exactly how, thus shedding light on important and insufficiently studied aspects of migration. A close-up view of the processes by which ideas, practices, norms, values and, according to some definitions, social capital and social skills are transferred by migrants across international borders helps researchers to understand more pre-cisely how migration contributes to social change or, in some cases, prevents it from occurring. Our article reviews some of the most interesting arguments and findings presented recently by other scholars and discusses aspects of social remitting which particularly interested us in our own research. The context of our research is social change in Poland: we attempt to understand how migration has con-tributed to wider patterns of social change since 1989 and exactly how it intertwines with other social trends and globalisation influences. This entails a careful focus on both structural conditions and agency and therefore on social remittances.

In contrast to the apparently stringent EU legal regime, the deportation of EU nationals is a law enforcement device widely normalised in many European countries. Concerning deportation prac-tices, the allegedly critical divide between EU citizens and third-country nationals does not seem to make much sense in practice for some – Eastern European – national groups. Initially, this paper explores the scope and scale of this increasingly salient component of the EU deportation system, by drawing on data supplied by national databases. Additionally, it examines why and how the depor-tation of EU nationals has gained traction across the European borderscape, a phenomenon that has much to do with rampant xeno-racist attitudes, widespread concerns over so-called ‘criminal aliens’ and, last but not at all least, the street-level management of poor populations and low-profile public order issues. Finally, this paper scrutinises the strength of institutional inertias in the management of enduringly subordinated – and racialised – Eastern European populations.

This paper deals with the results of chemical pre-treatment of effluents from Chip Washing by coagulation. Three different, most frequently used coagulants i.e. calcium hydroxide, aluminium sulphate and ferric chloride were applied. Influence of single and simultaneous dosage of the reagents was investigated. Fully randomized block systems were applied in the factorial variance analysis and final approximation analytic-empiric mathematical equations with application of the central point method were formulated.

Disinfection of drinking water is usually carried out by chlorination process. This is a well known, effective technology, which has many advantages. however during this process dangerous for health byproducts, such as trihalornethanes as well as chlorate, chlorite and bromale arc formed. Another disinfection process. which has emerged as the most promising alternative to chlorination technique, is ozonation. In spite of undeniable advantages. there are certain undefined hazards resulting from this method of water treatment. It is especially due to formation of carcinogen bromale anions in bromide containing waters. Determination of bromale as well as other inorganic oxyhalides is usually carried out by ion chromatography with conductivity detection. The detection sensitivity can be improved by using alternative hyphenated techniques such as IC-ICPMS or IS-MS-MS. These techniques are very sensitive, but are highly sophisticated and the instrumentation is very expensive. "Post-column reactions". i.e. derivative techniques coupled with ion chromatography are a relatively cheap and good alternative. This paper is a review or the newest achievements in analytical techniques used for determination of inorganic oxyhalides by-products formed during various drinking water disinfection processes.

Waste plastics make up approximately 20% of the volume of landifill material and almost 10% of the weight. These products contain substantial energy recovery value, and also represent a potentia!iy valuable source of feedstock raw material for additional plastics production. Controlled pyrolysis offers a method of converting raw, mixed waste plastics back into feedstock grade liquids by the application of heat in the absence of oxygen. However, chlorine from the thermal degradation of polyvinyl chloride (PVC) can contaminate the reclamed liquids making them more difficult and expensive for processing, and also produce a corrosive atmosphere which makes processing more expresive. This paper reports on a study of the impact of PVC on the thermal degradation rates other plastics including polypropylene (PP), polystyrene (PS), low-density polyethylene (LDPE), high-density polyethylene (HDPE) and polyethylene terephthalate (PET) in a thermogravimetric analyzer (TGA). Commodity plastics were mixed at various ratios with PVC and analyzed by means of their degradation rates to determine the kinetic rate constants which were compared to the rates obtained for the pure plastics. The values of the kinetic parameters for the pure compounds were all very close to, or within the ranges obtained from the literature. The results indicated that the decomposition behavior of the mixtures differed from those of the pure polymers. These deviations were greatest for mixtures of PVC with polyethylene terephthalate where it was determined that the dehydrochlorination step of PVC catalyzes the decomposition of PET. Pyrolysis of mixtures of PVC and polysteryne at temperatures between 200° C and 350° C result in incomplete dehydrochlorination. This results in more chlorinated compounds being released at higher temperatures.

The study aims to estimate metal foam microstructure parameters for the maximum sound absorption coefficient (SAC) in the specified frequency band to obtain optimum metal foam fabrication. Lu’s theory model is utilised to calculate the SAC of metallic foams that refers to three morphological parameters: porosity, pore size, and pore opening. After Lu model validation, particle swarm optimisation (PSO) is used to optimise the parameters. The optimum values are obtained at frequencies 250 to 8000 Hz, porosity of 50 to 95%, a pore size of 0.1 to 4.5 mm, and pore opening of 0.07 to 0.98 mm. The results revealed that at frequencies above 1000 Hz, the absorption efficiency increases due to changes in the porosity, pore size, and pore opening values rather than the thickness. However, for frequencies below 2000 Hz, increasing the absorption efficiency is strongly correlated with an increase in foam thickness. The PSO is successfully used to find optimum absorption conditions, the reference for absorbent fabrication, on a frequency band 250 to 8000 Hz. The outcomes will provide an efficient tool and guideline for optimum estimation of acoustic absorbents.

If we want to provide the efficient training intervention to increase the duration of using hearing protection devices (HPDs) by workers, we need a tool that can estimate the person’s hearing threshold taking into account noise exposure level, age, and work history, and compare them with audiometry to find out the percent reduction of workers hearing loss.

First, the workers noise exposure level was determined according to ISO 9612, then 4000 Hz audiometry was done to find age and work history. On basis of ISO 1999 the hearing threshold was estimated and if the hearing protection device was not used continuously and correctly, the hearing protection device’s actual performance was reduced adjusted with person’s audiometry. After training intervention, the estimate was done again and was compared with the adjusted audiometry.

According to ISO 1999 standard estimation results, the percent reduction of the workers hearing loss level was 6.48 dB in intervention group. This level remained unchanged in control group. The mean score of hearing threshold estimation (standard ISO 1999) was statistically more significant than mean score of hearing threshold (p-value ¡ 0.001). The results show not significant change in control group due to lack of changing of noise exposure level.

In regards to the results of hearing threshold estimation based on ISO 1999 and comparing with workers audiometry, it can be seen that BASNEF training intervention increases the duration of using the HPDs and it could be effective in reducing hearing threshold related to noise.

The paper presents results of a study concerning ammonium and nitratc(V) fixation by soil irrigated with municipal wastcwatcrs ( 1 - 60 mm and 2 doses - 120 mm) and estimation or the possibility or using organic soil and grass-mixture for the wastewater treatment. It was found that the studied soil and the plant applied showed a very high capacity or binding ammonium ions (up to 96%), and lower in the case ofnitrates(V) (up to 71 %). It was also demonstrated that the single irrigation dose was better utilized compared to the double dose.