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Energy security of the European Union and corruption in Central Asia as the main challenges for the European sustainable energy future
Bojana Vasić, Ivan Pekić, Goran Šimić, 2023, izvirni znanstveni članek

Opis: Background The main goal of the paper is to define, analyze and assess the basic security, development and institutional challenges faced by the Central Asian countries after 2022. Following the COVID-19 pandemic, and with the outbreak of the Ukrainian crisis, Europe faced problems in ensuring energy security, which were further complicated by its decision to stop importing natural gas from the Russian Federation. The Central Asian region is rich in energy resources, but at the same time, it is also a region of special geopolitical interest of often-conflicting parties, characterized by limited information and insufficient academic literature about development, various aspects of security, internal specificities and future challenges. Methods The research included qualitative and quantitative analyses carried out for Kazakhstan, the Kyrgyz Republic, Turkmenistan, Uzbekistan, Tajikistan and Germany. Data processing was performed based on 16 selected indicators in the fields of economy, energy, governance and climate change, for the time period 2011 to 2021. Data processing was performed using correlation and regression analysis (ANOVA). Results The results showed that corruption represents one of the biggest problems faced by the countries of Central Asia, with the biggest variations in the calculated Standardized Confidence level, which shows that this indicator trend, in relation to the 16 indicators used, is the least predictable. This represents a significant problem for all countries that are supplied with energy products from this region, or plan to do so. Energy security is positive only in the case of Turkmenistan. Regression analysis shows that Kazakhstan reported the best positive trend for most indicators. Data for Germany show consistent values over the observed period. Conclusions The main conclusions of the paper indicate that the countries of Central Asia have certain specificities when it comes to sustainable development, where energy security, corruption and government efficiency can be considered the biggest problems. The European Union must find ways and mechanisms to overcome these and many other impediments if they decide to import energy products from the aforementioned region.
Ključne besede: energy security, corruption perception, governance efectiveness, Central Asia, Germany
Objavljeno v DKUM: 15.04.2024; Ogledov: 12; Prenosov: 0
.pdf Celotno besedilo (1,59 MB)
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The Evaluation of Torrefaction Efficiency for Lignocellulosic Materials Combined with Mixed Solid Wastes
Maja Ivanovski, Darko Goričanec, Danijela Urbancl, 2023, izvirni znanstveni članek

Opis: The paper presents the results of research aimed at evaluating the possibility of using selected biomass wastes to produce solid biofuels. In this work, the thermochemical properties of two lignocellulosic biomasses, namely, miscantshus (Miscanthus × Giganteus) and hops (Humulus lupulus), and non-lignocellulosic biomass, namely, municipal solid waste, and their mixtures (micanthus + municipal solid waste and hops + municipal solid waste) were studied using the torrefaction process as the main method for investigation. The effects of various torrefaction temperatures (250, 300, and 350 °C) and times (30 and 60 min) were evaluated. Proximate and ultimate analyses were performed on the torrefied samples. The following can be stated: as the torrefaction temperature and time increased, mass and energy yields decreased while the higher heating values (HHVs) and fuel ratios (FRs) increased, together with carbon contents (C). In addition, energy on return investment (EROI) was studied; the maximum EROI of 28 was achieved for MSW biochar at 250 °C for 30 min. The results of studying greenhouse gas emissions (GHGs) showed a reduction of around 88% when using torrefied biochar as a substitute for coal. In sum, this study shows that torrefaction pre-treatment can improve the physicochemical properties of raw biomasses to a level comparable with coal, and could be helpful in better understanding the conversion of those biomasses into a valuable, solid biofuel.
Ključne besede: torrefaction, waste biomass, renewable energy, fuel ratio, greenhouse gas emission, GHG
Objavljeno v DKUM: 29.03.2024; Ogledov: 51; Prenosov: 2
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Autolysis affects the iron cargo of ferritins in neurons and glial cells at different rates in the human brain
Sowmya Sunkara, Snježana Radulović, Saška Lipovšek Delakorda, Christoph Birkl, Stefan Eggenreich, Anna Maria Birkl-Toeglhofer, Maximilian Schinagl, Daniel Funk, Michael Stöger-Pollach, Johannes Haybaeck, Walter Gössler, Stefan Ropele, Gerd Leitinger, 2023, izvirni znanstveni članek

Opis: Iron is known to accumulate in neurological disorders, so a careful balance of the iron concentration is essential for healthy brain functioning. An imbalance in iron homeostasis could arise due to the dysfunction of proteins involved in iron homeostasis. Here, we focus on ferritin—the primary iron storage protein of the brain. In this study, we aimed to improve a method to measure ferritin-bound iron in the human post-mortem brain, and to discern its distribution in particular cell types and brain regions. Though it is known that glial cells and neurons differ in their ferritin concentration, the change in the number and distribution of iron-filled ferritin cores between different cell types during autolysis has not been revealed yet. Here, we show the cellular and region-wide distribution of ferritin in the human brain using state-of-the-art analytical electron microscopy. We validated the concentration of iron-filled ferritin cores to the absolute iron concentration measured by quantitative MRI and inductively coupled plasma mass spectrometry. We show that ferritins lose iron from their cores with the progression of autolysis whereas the overall iron concentrations were unaffected. Although the highest concentration of ferritin was found in glial cells, as the total ferritin concentration increased in a patient, ferritin accumulated more in neurons than in glial cells. Summed up, our findings point out the unique behaviour of neurons in storing iron during autolysis and explain the differences between the absolute iron concentrations and iron-filled ferritin in a cell-type-dependent manner in the human brain.
Ključne besede: ferritin, human brain, energy-filtered transmission electron microscopy, quantitative magnetic resonance imaging, autolysis
Objavljeno v DKUM: 20.03.2024; Ogledov: 94; Prenosov: 14
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Privacy and data protection concerns in the regulatory framework of Slovenian energy law
Zoran Dimović, 2023, izvirni znanstveni članek

Opis: The implementation of smart energy systems (SES) in the Slovenian energy sector has raised significant privacy and data protection concerns. The collection and processing of personal data from energy consumers, as well as cybersecurity threats, pose risks that must be addressed. The legal framework governing privacy and data protection in the energy field in Slovenia is based on the GDPR, ZOEE, ZVPot-1, ZVOP-2 and others, which impose significant obligations on entities processing personal data. To mitigate these risks, exact terminology must be used to implement privacy, data protection and also cybersecurity measures and ensure compliance with the legal framework.
Ključne besede: cybersecurity, data protection, energy law, green and digital transformation, privacy protection
Objavljeno v DKUM: 20.02.2024; Ogledov: 126; Prenosov: 7
.pdf Celotno besedilo (456,29 KB)
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Transitioning towards Net-Zero Emissions in Chemical and Process Industries : A Holistic Perspective
Peter Glavič, Zorka Novak-Pintarič, Helena Levičnik, Vesna Dragojlović, Miloš Bogataj, 2023, pregledni znanstveni članek

Opis: Given the urgency to combat climate change and ensure environmental sustainability, this review examines the transition to net-zero emissions in chemical and process industries. It addresses the core areas of carbon emissions reduction, efficient energy use, and sustainable practices. What is new, however, is that it focuses on cutting-edge technologies such as biomass utilization, biotechnology applications, and waste management strategies that are key drivers of this transition. In particular, the study addresses the unique challenges faced by industries such as cement manufacturing and highlights the need for innovative solutions to effectively reduce their carbon footprint. In particular, the role of hydrogen as a clean fuel is at the heart of revolutionizing the chemical and process sectors, pointing the way to cleaner and greener operations. In addition, the manuscript explores the immense importance of the European Green Deal and the Sustainable Development Goals (SDGs) for the chemical industry. These initiatives provide a clear roadmap and framework for advancing sustainability, driving innovation, and reducing the industry's environmental impact, and are a notable contribution to the existing body of knowledge. Ultimately, alignment with the European Green Deal and the SDGs can bring numerous benefits to the chemical industry, increasing its competitiveness, promoting societal well-being, and supporting cross-sector collaboration to achieve shared sustainability goals. By highlighting the novelty of integrating cutting-edge technologies, addressing unique industrial challenges, and positioning global initiatives, this report offers valuable insights to guide the chemical and process industries on their transformative path to a sustainable future.
Ključne besede: net zero, energy, process industries, emissions, climate, chemicals, biomass, waste, cement, metals
Objavljeno v DKUM: 19.02.2024; Ogledov: 135; Prenosov: 2
.pdf Celotno besedilo (894,06 KB)
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Integrating social dimensions into future sustainable energy supply networks
Matevž Obrecht, Yigit Kazancoglu, Matjaž Denac, 2020, izvirni znanstveni članek

Opis: Environmental protection and sustainable development have become an inevitable trend in many areas, including the energy industry. The development of energy supply networks is strongly correlated with the economics of energy sources as well as ecological and socio-political issues. However, the energy supply network is often distant from the social perspective. This paper therefore combines examination of perceptions and awareness of general public (web-based questionnaire) and top energy experts (a Delphi survey) on the energy supply network and identifies their potential integration in energy supply decision making processes. The results showed that public should be better informed as well as integrated into designing energy supply network as the prosumers gain power and the energy suppliers will no longer dominate the market. Public actors are ready to shape sustainable energy supply and also willing to pay 5.8% more for a sustainable energy supply. The majority are prepared to invest in renewable energy supply network close to their place of residence. Another result is that the public is calling for a shift in priority towards more sustainable and socially friendlier energy supply rather than focusing mainly on the economic and technical perspectives.
Ključne besede: energy supply, supply networks, sustainable energy, public perception, social integration, supply chain management
Objavljeno v DKUM: 19.02.2024; Ogledov: 111; Prenosov: 2
.pdf Celotno besedilo (1,60 MB)
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Food Waste to Energy through Innovative Coupling of CHP and Heat Pump
Jan Drofenik, Danijela Urbancl, Darko Goričanec, Zdravko Kravanja, Zorka Novak-Pintarič, 2023, izvirni znanstveni članek

Opis: This paper presents the conceptual design of a technological solution for the efficient conversion of food waste into heat and power. The distribution and composition of food loss and waste at different stages of the food supply chain in Slovenia and their potential for biogas production were determined. It was found that more than 50% of food waste comes from households. Therefore, a small plant was designed to convert food waste into biogas, which was innovatively coupled with a combined heat and power (CHP) unit and a heat pump. This doubles the amount of heat generated compared to conventional cogeneration. Based on the capacity of a micro commercial CHP unit, 3330 households (about 8000 residents) would supply food waste. The heat generated could replace 5% of the natural gas used for domestic water heating. The payback period would be 7.2 years at a heat price of about 80 EUR/MWh, however, for municipalities with more than 40,000 inhabitants the payback period would be reduced to less than 3 years. The cost price of the heat generated by this system would be about 25 EUR/MWh, taking into account the government subsidy for the operation of the CHP unit.
Ključne besede: food waste to energy, biogas, combined heat and power, CHP, heat pump, efficiency, conceptual design, preliminary economic assessment, sensitivity analysis
Objavljeno v DKUM: 16.02.2024; Ogledov: 2971; Prenosov: 6
.pdf Celotno besedilo (19,44 MB)
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Investigating Winter Temperatures in Sweden and Norway : Potential Relationships with Climatic Indices and Effects on Electrical Power and Energy Systems
Younes Mohammadi, Aleksey Palstev, Boštjan Polajžer, Seyed Mahdi Miraftabzadeh, Davood Khodadad, 2023, izvirni znanstveni članek

Opis: This paper presents a comprehensive study of winter temperatures in Norway and northern Sweden, covering a period of 50 to 70 years. The analysis utilizes Singular Spectrum Analysis (SSA) to investigate temperature trends at six selected locations. The results demonstrate an overall long-term rise in temperatures, which can be attributed to global warming. However, when investigating variations in highest, lowest, and average temperatures for December, January, and February, 50% of the cases exhibit a significant decrease in recent years, indicating colder winters, especially in December. The study also explores the variations in Atlantic Meridional Overturning Circulation (AMOC) variations as a crucial climate factor over the last 15 years, estimating a possible 20% decrease/slowdown within the first half of the 21st century. Subsequently, the study investigates potential similarities between winter AMOC and winter temperatures in the mid to high latitudes over the chosen locations. Additionally, the study examines another important climatic index, the North Atlantic Oscillation (NAO), and explores possible similarities between the winter NAO index and winter temperatures. The findings reveal a moderate observed lagged correlation for AMOC-smoothed temperatures, particularly in December, along the coastal areas of Norway. Conversely, a stronger lagged correlation is observed between the winter NAO index and temperatures in northwest Sweden and coastal areas of Norway. Thus, NAO may influence both AMOC and winter temperatures (NAO drives both AMOC and temperatures). Furthermore, the paper investigates the impact of colder winters, whether caused by AMOC, NAO, or other factors like winds or sea ice changes, on electrical power and energy systems, highlighting potential challenges such as reduced electricity generation, increased electricity consumption, and the vulnerability of power grids to winter storms. The study concludes by emphasizing the importance of enhancing the knowledge of electrical engineering researchers regarding important climate indices, AMOC and NAO, the possible associations between them and winter temperatures, and addressing the challenges posed by the likelihood of colder winters in power systems.
Ključne besede: winter temperatures, biogas, Atlantic Meridional Overturning Circulation, AMOC, weaking, NAO, North Atlantic Oscillation, SSA, Singular Spectrum Analysis, electrical power and energy systems
Objavljeno v DKUM: 15.02.2024; Ogledov: 140; Prenosov: 6
.pdf Celotno besedilo (8,94 MB)
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Comparative analysis of batteries for photovoltaic systems : bachelor's thesis
Kristina Gočanin, 2023, diplomsko delo

Opis: Renewable energies represent unlimited power sources that are significantly reducing greenhouse emissions. The possibilities and advantages of abundantly available solar energy are immense. However, some challenges are preventing solar energy from reaching its full potential regarding its efficiency and energy storage. Therefore, the main focus of this thesis is on electrochemical storage systems. The aim is to compare the currently leading technology – Li-ion battery to the most recent breakthrough in storage systems – the solid-state battery. The thesis includes a comparative analysis of the mentioned technologies, as well as the theoretical part that introduces solar energy and photovoltaic systems with their main components.
Ključne besede: photovoltaic system, energy storage, analysis, Li-ion battery, solid-state battery
Objavljeno v DKUM: 30.01.2024; Ogledov: 193; Prenosov: 24
.pdf Celotno besedilo (2,35 MB)

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