The following paper presents the process of decarbonization of the energy sector in Greece and points out to different methods the Greek authorities are adopting in order to reduce the emission of greenhouse gases generated by electricity production. Greece is a country which is modernizing its energy sector gradually, yet dynamically. One of the prime aims is to reduce the level of energy produced in coal-fired power plants by focusing on the renewable energy and the gas sector. In 2010 still more than half of the electrical energy was generated by lignite-fired power plants. Almost ten years later the ratio has dropped to only slightly more than 30%. A significant reduction in coal consumption was possible thanks to investments in renewable energy sources, especially in the wind and solar energy sectors. Both sectors have seen a large increase in production, making renewable energy sources already accounting for over 20% of Greek electricity production. Capital-intensive investments were also made in the country’s gas supply through the expansion of gas-fired power plants and gas transmission networks. As a result, natural gas remains the main source of energy for Greece next to coal. Unfortunately, a big challenge in terms of decarbonization is the need for increased imports of electricity from abroad, due to the insufficient capacity of the Greek energy sector. Therefore, the main purpose of this paper is to define a Greek model of decarbonization and to point out to its benefits and dangers. Greek strategy might serve as an example of how to successfully solve the energy issues in the countries with similar energy profile.

This paper summarizes the arguments and counterarguments within the scientific discussion

on developing the free-carbon economy in Ukraine. The main purpose of the paper is elaborating

the energy efficiency profile of Ukraine to assure the development of the free-carbon economy. To

achieve this purpose, the authors carried out an investigation in the following logical sequence.

Firstly, the bibliometric analysis of 4674 of the most cited articles indexed by the Scopus database

was conducted. The obtained findings indicated that the green economy transformation depended

on the main factors such as economic performance, corruption, macroeconomic stability, social

welfare, shadow economy etc. As a result, the forecast of the final energy consumption to 2030

was performed. The methodological tool of this research is based on the Autoregressive Integrated

Moving Average (ARIMA) model. This study involved data of the Visegrad countries (Poland, the

Czech Republic, the Slovak Republic and Hungary) and Ukraine from 2000 to 2018. The base of

data is Eurostat, the EU statistical service. Based on the obtained results of analyzing the green

economic transformation in the Visegrad countries and Ukraine, the authors intimated the existence

of the significant energy-efficient gap in Ukraine compared to the analyzed countries. In reliance on

the experience of the Visegrad countries and the forecast results, the authors provided the main recommendations

for providing the green transforming in Ukraine. The authors highlighted that the obtained

results of this paper were considered to be the base for future investigations considering the influence

of endogenous and exogenous factors on developing the free-carbon economy in Ukraine.

In the present study, we analyse the influence of goal maintenance and goal change on the efficiency of executive control. Although there is empirical evidence on the impact of goal maintenance and task-switching on executive control, little is known about the consequences of changing between processing goals (e.g., speed or accuracy goals). We assessed the influence of changing between speed and accuracy goals while performing a task-switching procedure that requires social categorization. Experiment 1 included frequent goal changes, whereas Experiment 2 included one goal change across the experimental session. The results showed that both goals influence general performance and flexibility. A comparison between experiments suggested that frequent goal change (Experiment 1) resulted in worse performance and lower flexibility overall, compared to sequential goal change (Experiment 2). Frequent goal change was also associated with increased difficulties in pursuing the accuracy goal. The implications regarding the role of goal maintenance and goal change on executive control are discussed, as well as new research possibilities.

Noise reduction inside waveguide systems has gained momentum owing to a great interest in it. To attenuate the sound in a broad frequency range, this study aims to compare the effects of two acoustic liners, a perforated plate backed by an air cavity (PP-Air cavity), or by a porous material (PP-PM), on the acoustic behaviour of lined ducts using a numerical model to compute the multimodal scattering matrix. From this matrix, the reflection and the transmission coefficients are computed and therefore the acoustic power attenuation is deduced. Moreover, the effects of geometry of ducts with and without changes in the section are investigated. The numerical results are obtained for five configurations, including cases of narrowing and widening of a duct portion with sudden or progressive discontinuities. Accordingly, numerical coefficients of reflection and transmission as well as the acoustic power attenuation show the relative influence of acoustic liners in each type of configuration.

Na podstawie chińskich zasobów i statystyk dotyczących katastrof w kopalniach węgla stwierdzono, że istnieje wiele niedociągnięć w zarządzaniu katastrofami i ryzykiem na obszarach górniczych w Chinach. Dlatego, aby naukowo i efektywnie zarządzać obszarami górniczymi, w oparciu o teorię kontroli wewnętrznej, w artykule systematycznie analizuje się ryzyko obszarów górniczych pod kątem różnych czynników i odpowiednich sugestii. Od wystąpienia ryzyka górniczego do wystąpienia szkód podkreśla się znaczenie zarządzania ryzykiem. Zgodnie z pięcioma zasadami wyboru wskaźników oceny: zasadą celu, zasadą kompleksowości, zasadą naukowości, zasadą terminowości i zasadą ukierunkowania, a także pięcioma elementami kontroli wewnętrznej: środowiskiem kontroli, oceną ryzyka, działaniami kontrolnymi, informacją i komunikacją oraz nadzorem, skonstruowano ramy zarządzania ryzykiem w obszarze górniczym w zakresie zakłóceń w zarządzaniu ludźmi, maszynami i środowiskiem oraz podzielono 27 drugorzędnych wskaźników ryzyka. Ustalono kryteria określania poziomu ryzyka i proces reagowania na ryzyko, a także stworzono bardziej systematyczny i dokładny system zarządzania ryzykiem kopalnianym w ramach teorii kontroli wewnętrznej. Wreszcie, w oparciu o cztery kluczowe technologie, stworzono podwójny mechanizm zapobiegania i kontroli ryzyka systemowego i systemu zarządzania ryzykiem zawodowym. Zapewnia to nowe metody i pomysły w zakresie zapobiegania i kontroli zagrożeń bezpieczeństwa w kopalniach węgla oraz ograniczania katastrof i wypadków.

Celem artykułu jest pokazanie sytuacji energetycznej Finlandii po agresji Rosji na Ukrainę oraz związanym z tym faktem wstąpieniem tego kraju do struktur NATO. Sytuacja taka ma miejsce po raz pierwszy w historii i analiza tego zjawiska jest ważnym elementem planowania polityki energetycznej dla innych państw. W artykule pokazano, jak można szybko i skutecznie podejmować decyzje mające wpływ na bezpieczeństwo energetyczne kraju.
Finlandia ze względu na swoje położenie geograficzne oraz uwarunkowania historyczne do niedawna była ściśle powiązana gospodarczo ze Związkiem Radzieckim, a następnie z Rosją. Sytuacja ta zmieniła się jednak diametralnie po napaści Rosji na Ukrainę. Spowodowało to zmianę myślenia polityków odpowiedzialnych za bezpieczeństwo, w tym bezpieczeństwo energetyczne.
Ze względu na brak zasobów surowców energetycznych oraz w celu dążenia do osiągnięcia neutralności klimatycznej, Finlandia sukcesywnie zwiększa udział OZE w swoim miksie energetycznym. Rozwijana jest również energetyka jądrowa stanowiąca jedno z najważniejszych źródeł produkcji energii elektrycznej w tym kraju. W 2021 roku miała 33% udział w całkowitej produkcji energii elektrycznej, a dwie fińskie elektrownie jądrowe mają łączną moc zainstalowaną wynoszącą 4,39 GW. Własna produkcja oraz import z bezpiecznych kierunków to podstawa bezpieczeństwa energetycznego Finlandii, zwłaszcza po wstrzymaniu dostaw energii elektrycznej i gazu z Rosji w maju 2022 roku. Obecnie energia elektryczna importowana jest głównie ze Szwecji, a gaz gazociągiem z Estonii oraz przez trzy małe terminale LNG. Zgodnie z planami rządu fińskiego od 2030 roku Finlandia ma się stać eksporterem energii elektrycznej dzięki zwiększaniu produkcji energii elektrycznej z elektrowni jądrowych oraz ze źródeł odnawialnych. Planowane jest też wykorzystywanie w większym zakresie pomp ciepła oraz ciepła odpadowego w ogrzewnictwie.

Consumption of energy is one of the important indicators in developing countries, but a lot of companies from the energy sector have to cope with three key challenges, namely how to reduce their impact on the environment, how to ensure the low cost of the energy production and how to improve the system overall performance? For Polish energy market, the number of challenges is greater. The growing demand for electricity and contemporary development of nuclear power technology allow today’s design, implement new solutions for high energy conversion system low unit cost for energy and fuel production. In the present paper, numerical analysis of modular high-temperature nuclear reactor coupled with the steam cycle for electricity production has been presented. The analysed system consists of three independent cycles. The first two are high-temperature nuclear reactor cycles which are equipped with two high-temperature nuclear reactors, heat exchangers, blowers, steam generators. The third cycle is a Rankine cycle which is equipped with up to four steam turbines, that operate in the heat recovery system. The analysis of such a system shows that is possible to achieve significantly greater efficiency than offered by traditional nuclear reactor technology.

W artykule omawiam najnowsze dyskusje na temat metodologicznego statusu wiedzy naukowej w obrębie akademii i poza akademią. Dyskutuję kwestie spadku zaufania społecznego do nauki (społeczeństwo ryzyka i strachu) oraz post-prawdy. Przedstawiam trzy stanowiska, określające relacje pomiędzy oficjalną nauką akademicką a innymi formami wiedzy (wiedzy laików) oraz formami użycia wiedzy poza akademią (w polityce). Pierwsze stanowisko to modernizm wyboru Harry’ego Collinsa i Roberta Evansa ujmujące trzecią falę sporów o naukę. Modernizm wyboru określa sposób podejmowania decyzji politycznych z rekomendacji uczonych, którzy mają samoświadomość metodologiczną możliwości i ograniczeń wiedzy naukowej. Drugim stanowiskiem jest propozycja Steve’a Fullera nauki protestanckiej jako formy wiedzy na własny użytek uwarunkowanej post-prawdą. W tym ujęciu wiedzę może wytwarzać każdy, ale musi ona spełniać specyficzne kryteria. Trzecim stanowiskiem jest zaproponowane przez Marka R. Browna ujęcie wiedzy eksperckiej jako reprezentacji rozmaitych opcji światopoglądowych czy kulturowych; ich reprezentanci zlecają ekspertom stosowne przedstawienie rekomendacji do podjęcia określonych decyzji politycznych.

węgiel kamienny, macerały, refleksyjność witrynitu, koks metalurgiczny, CSR, CRI

In the article we study a model of network transmissions with Active Queue Management in an intermediate IP router. We use the OMNET++ discrete event simulator to model the varies variants of the CHOKe algoithms. We model a system where CHOKe, xCHOKe and gCHOKe are the AQM policy. The obtained results shows the behaviour of these algorithms. The paper presents also the implementation of AQM mechanisms in the router based on Linux.

The aim of this paper is to present a way of ranking the nonlinearities of electrodynamic loudspeakers. For this purpose, we have constructed a nonlinear analytic model which takes into account the variations of the small signal parameters. The determination of these variations is based on a very precise measurement of the electrical impedance of the electrodynamic loudspeaker. First, we present the experimental method to identify the variations of these parameters, then we propose to study theoretically the importance of these nonlinearities according to the input level or the input frequency. We show that the parameter which creates most of the distortions is not always the same and depends mainly on both the input level and the input frequency. Such results can be very useful for optimization of electrodynamic loudspeakers.

In the search for the critical functions of theology, we can find a growing number of dilemmas, which come from the theology itself and from the modern knowledge about the world, which theology has to face, not only offering expected answers, but also formulating its own Christian doctrine proper for contemporary times and consistent with the Tradition of faith. The only way to present such a broad and difficult problem in a short paper is through a general perspective. The key to the systematization of the problem is by observing that the tasks of theology can be seen from four different perspectives, according to the distinction ad extra – ad intra. Astrong emphasis is put on the encounter between theology and science. The attempt to make predictions about the future is based on analysis of the contemporary situation in theology and on the extrapolation of existing trends for the near future.

Background: The older population is very heterogeneous with regard to the co-morbidity and the physical reserve. This can result in unacceptably high postoperative complications rates. Th erefore, the aim of the study was to review the literature regarding the outcomes of older patients treated for pancreatic cancer, including the usage of minimal invasive techniques.

Methodology: A review of the literature was carried out including studies on pancreatic cancer in older patients published between 2011 and 2016.

Results: Seventeen retrospective studies were included. The total number of patients was 9981 with the age range of 65 years and more. Studies on surgical treatment alone (1.4%), neoadjuvant/adjuvant treatment with or without surgery (89.4%) and palliative therapy (9.2%) were assessed separately. Appropriate comparison was diffi cult due to the retrospective character and heterogeneity of the study population. Mortality was low, yet there was a great diff erence in morbidity ranging from some percent to even 100% of the study population. Long-term results were poor.

Conclusions: The functional status, not the chronological age alone, is the factor limiting therapeutic options in older patients with pancreatic cancer.

Organic carbon, nitrogen, and phosphorus in the soils of the High Arctic play an important role in the context of global warming, biodiversity, and richness of tundra vegetation. The main aim of the present study was to determine the content and spatial distribution of soil organic carbon (SOC), total nitrogen (N tot ), and total phosphorus (P tot ) in the surface horizons of Arctic soils obtained from the lower part of the Fuglebekken catchment in Spitsbergen as an example of a small non−glaciated catchment representing uplifted marine terraces of the Svalbard Archipelago. The obtained results indicate that surface soil horizons in the Fuglebekken catchment show considerable differences in content of SOC, N tot , and P tot . This mosaic is related to high variability of soil type, local hydrology, vegetation (type and quantity), and especially location of seabird nesting colony. The highest content of SOC, N tot , and P tot occurs in soil surface horizons obtained from sites fertilized by seabird guano and located along streams flowing from the direction of the seabird colony. The content of SOC, N tot , and P tot is strongly negatively correlated with distance from seabird colony indicating a strong influence of the birds on the fertility of the studied soils and indirectly on the accumulation of soil organic matter. The lowest content of SOC, N tot , and P tot occurs in soil surface horizons obtained from the lateral moraine of the Hansbreen glacier and from sites in the close vicinity of the lateral moraine. The content of N tot ,P tot , and SOC in soil surface horizons are strongly and positively correlated with one another, i.e. the higher the content of nutrients, the higher the content of SOC. The spatial distribution of SOC, N tot , and P tot in soils of the Hornsund area in SW Spitsbergen reflects the combined effects of severe climate conditions and periglacial processes. Seabirds play a crucial role in nutrient enrichment in these weakly developed soils.