bluuebunny/crossref_metadata_2025 huggingface dataset:
THE NATIONAL QUESTION DURING THE FIRST WORLD WAR: VISION OF MYKHAILO HRUSHEVSKY
Authors: YANYSHYN Bohdan
Published: May 2024

The purpose of the study is to fi nd out the peculiarities of the coverage of national issues in the journalism of M. Hrushevsky during the period of the fi rst exile. The methodological basis of the work is an interdisciplinary approach. Particular emphasis is placed on the structural and functional system analysis of historiographical facts and the method of critical analysis of documentary material. The scientifi c novelty of the article consists in an attempt to comprehensively analyze the ethnological visions of M. Hrushevsky during the Great War. Conclusions. Summing up M. Hrushevsky’s journalism during theyears of exile, we should fi rst of all note his position as a Ukrainian intellectual who, despite considerable danger to his own life, consistently defended the interests of his people with the printed word. Noting the next dangers for the existence of Ukrainians caused by the world confrontation, the scientist found the right words to support his compatriots who found themselves in diffi cult conditions, inspiring them with his own example to tirelessly serve the people by all possible means. He considered the war years as a unique opportunity to reset the tangled relations with our historical neighbors, who for centuries saw Ukraine as building material for their own nation-building projects. Calling on the opinion leaders of the Russian and Polish communities to abandon imperial rhetoric, M. Hrushevsky pointed to the need and possibility of establishing an equal international dialogue based on the paraphrasedprinciple of the humanistic philosophy “natio nationi res sacra”. Certainly, one can argue about the realism of the scientist’s nationalistic visions of that time. But one thing seems indisputable – their consideration would have prevented many tragic events of the last century.It is precisely with this considerable prognostic potential that M. Hrushevsky’s journalism continues to attract researchers of the intellectual history of Central-Eastern Europe.
DISCIPLINARY RESPONSIBILITY AND TRIAL IN THE UKRAINIAN INSURGENT ARMY (1943 – 1947)
Authors: ANTONIUK Yaroslav , ILNYTSKYI Vasyl
Published: May 2024

The purpose of the article is to study the peculiarities of the formation of the basic principles of disciplinary responsibility and the organization of judicial proceedings in the Ukrainian Insurgent Army (1943 – 1947). The research methodology is based on the principles of scientificity, systematicity, general scientific (analysis, synthesis) and special-historical (historical-typological, historical-systemic, historical-comparative) methods and methods of criticism of historical sources. The scientific novelty lies in the fact that, on the basis of unknown and little-known sources, a comprehensive study of judicial and disciplinary practice in the Ukrainian Insurgent Army (1943 – 1947) was conducted. Conclusions. Thus, the Principles of Judicial and Disciplinary Practice in the Ukrainian Insurgent Army were initiated in the summer of 1943 in the territories of Volyn and Western Polissia. At the end of the same year, the insurgent judiciary spread to Galicia and the neighboring territories of eastern Poland and Slovakia. The main judicial and disciplinary bodies in the units of the UPA were “Field Courts”. If necessary, they convened at every hundred. It was assumed that one of the three judges of the “Field Court” would hold a position not lower than the level of centurion, the second – squad leader. Sentences were handed down on the basis of the “UPA Disciplinary Statute”. In it, crimes were divided into light and serious. The latter included: treason, vandalism, failure to comply with an order that led to significant losses, repeated desertion. Those accused of serious crimes were mostly executed. The commander of the relevant rebel unit approved the verdict of the “Field Court”. “Cossack courts” usually dealt with minor crimes. They were summoned by the commanders of insurgent units in case of: drunkenness, failure to comply with an order without serious consequences, minor thefts. The sentences were: sending to the “penal departments”, “criminal arrest”, “shompoling” in front of the line, “standing under the gun” or “falling of fates” on command. In case of repeated prosecution, the punishment was increased up to and including execution
Radikalisme Timur-Tengah dan Pengaruhnya di Indonesia
Authors: Darman Andrianus , Metodius Fabrizio Olie Valdo , Sitohang Leopoldus Giovani , Letsoin Yetva Softiming , Blareq Yoseph Koverino Gedu
Published: May 2024

In this search, our focus is on Middle-Eastern radicalism and its impact on the Indonesian nation. It seems that radicalism in the Middle East arises from its own historical, political and cultural context. Therefore, it is very peculiar to apply it in this country, since Indonesia has its own particular historical, political and cultural context. However, it is inevitable that the notion of radicalism has entered Indonesia through certain groups, individuals, social media, or networks affiliated with radicalist networks in the Middle East. This fact needs to be addressed by establishing a deradicalization institution and by preserving the treasures of the arts, culture and ethics of the country, Nusantara.
Permanence of the torsion-freeness property for divisible discrete quantum subgroups
Authors: Martos Rubén
Published: May 2024

We prove that torsion-freeness in the sense of Meyer-Nest is preserved under divisible discrete quantum subgroups. As a consequence, we obtain some stability results of the torsion-freeness property for relevant constructions of quantum groups (quantum (semi-)direct products, compact bicrossed products and quantum free products). We improve some stability results concerning the Baum-Connes conjecture appearing already in a previous work of the author. For instance, we show that the (resp. strong) Baum-Connes conjecture is preserved by discrete quantum subgroups (without any torsion-freeness or divisibility assumption).
The Kalton-Peck space as a spreading model
Authors: Suárez Jesús
Published: May 2024

The so-called Kalton-Peck space $Z_2$ is a twisted Hilbert space induced, using complex interpolation, by $c_0$ or $\ell _p$ for any $1\leq p\neq 2<\infty $. Kalton and Peck developed a scheme of results for $Z_2$ showing that it is a very rigid space. For example, every normalized basic sequence in $Z_2$ contains a subsequence which is equivalent to either the Hilbert copy $\ell _2$ or the Orlicz space $\ell _M$. Recently, new examples of twisted Hilbert spaces, which are induced by asymptotic $\ell _p$-spaces, have appeared on the stage. Thus, our aim is to extend the Kalton-Peck theory of $Z_2$ to twisted Hilbert spaces $Z(X)$ induced by asymptotic $c_0$ or $\ell _p$-spaces $X$ for $1\leq p<\infty $. One of the novelties is to use spreading models to gain information on the isomorphic structure of the subspaces of a twisted Hilbert space. As a sample of our results, the only spreading models of $Z(X)$ are $\ell _2$ and $\ell _M$, whenever $X$ is as above and $p\neq 2$.
Ar ikiteisminio administracinių ginčų nagrinėjimo tvarkos reguliavimas poįstatyminiais teisės aktais atitinka teisinio apibrėžtumo principą?
Authors: Jakutavičius Mindaugas
Published: May 2024

Konstitucijoje yra įtvirtinta, kad asmuo gali kreiptis į teismą, kai jo teisės yra pažeistos. Demokratinėse valstybėse didėjant teismuose nagrinėjamų bylų skaičiui, dėl ilgo teisminio proceso asmuo ne visuomet gali laiku apginti savo pažeistas teises. Tai yra ypač aktualu, kada vyksta ginčai tarp asmens ir valstybės institucijų dėl institucijų priimtų sprendimų asmens atžvilgiu. Dėl to Europos Sąjungos (toliau – ES) lygmeniu buvo priimtos rekomendacijos, kuriomis siekiama skatinti ES valstybėse narėse tarp asmens ir valstybinės institucijos kylančius ginčus spręsti ikiteisminiu keliu nacionalinėje teisėje. Ikiteisminis administracinių ginčų nagrinėjimas yra paprastesnis ir efektyvesnis. Tokių ikiteisminių ginčų nagrinėjimui labiausiai tinkamos kvaziteisminės institucijos, kurios Europoje egzistuoja nuo XIX a., o jų paskirtis yra spręsti ikiteisminius administracinius ginčus, taip asmeniui sudarant galimybes greičiau apginti savo pažeistas teises. 1999 m. vykdant reformas Lietuvos administracinėje justicijos sistemoje ir Lietuvoje atsirado išankstinių administracinių ginčų sprendimo galimybių, tačiau nacionaliniu lygmeniu specialiose srityse yra leidžiama spręsti ikiteisminius administracinius ginčus ne tik pagrindinėms ikiteisminius administracinius ginčus sprendžiančioms institucijoms, bet ir kitoms valstybinėms institucijoms. Esant tokiam reglamentavimui, yra sudaromos prielaidos perkelti išankstinių ginčų nagrinėjimo tvarką į poįstatyminius teisės aktus. Todėl toks reglamentavimas gali būti ne visuomet aiškus, apibrėžtas ir suprantamas. Be to, kartais poįstatyminiuose teisės aktuose įtvirtintos teisės normos gali prieštarauti įstatymams.
Electric Vehicle Charging Infrastructure Study for Apartment Buildings
Authors: Lill Heiki
Published: May 2024

Changes in the engine type of cars aimed at climate goals also have an impact on the habit of electricity consumption at home. Charging electric cars from the residential grid also increases the total electricity consumption of the residential building. If all apartment owners in an apartment building want to charge their electric car at the same time, this may create a situation where the main protection of the apartment building is activated. The purpose of this research is to identify possible options to avoid this problem, based on different real-life data. For example: adding an energy storage to the electrical system of an apartment building is seen as one solution. Also supplement of an energy management software to the electrical and battery bank system to enables residents to schedule and prioritize their electric car charging times to avoid simultaneous high-demand periods. This system can also be used to optimize electricity distribution and consumption in apartment buildings under volatile electricity price conditions.
Exploring the Efficacy of Random Linear Parameter Models for Forecasting Heating Demand in District Heating Networks
Authors: Ali Hesham , Dedov Andrei , Volkova Anna
Published: May 2024

The heating and cooling sector accounts for approximately half of global energy consumption, making it a pivotal focus for energy transition efforts. District heating and cooling networks have emerged as efficient, innovative, and dominant technologies in various regions. Accurate forecasting of heating demand within these networks is imperative for effective energy transition and responsive demand management. While existing forecasting techniques primarily concentrate on limited parameters such as ambient temperature and time of day, this paper explores the multifaceted impact of various factors, including ambient temperature, energy prices, number of consumers, building types, and solar radiation, on heating demand. Through a comprehensive study of these determinants, a robust and efficient forecasting model is developed in this research. Specifically, a novel Random Linear Parameter Model (RLPM) is introduced for hourly heating demand forecasting within district heating networks. The model's performance is assessed and compared with existing forecasting models, namely Linear Regression, ARIMA, and RLPM. A notable advantage of the Random Parameter Linear Regression model lies in its capability to recognize unobserved parameters influencing demand and account for unobserved heterogeneity, providing a robust framework for incorporating these factors into the forecasting process. This study aims to underscore the proposed approach's advantages in terms of accuracy and its ability to estimate the determinants of heating load, thereby offering reliable future forecasting. The findings have the potential to significantly contribute to optimizing district heating systems by delivering more nuanced and dependable predictions of heating demand.
Techno-Economic Model of District Heating Energy Hub: The Case of Latvia
Authors: Zarins Emils , Rieksta Madara , Bazbauers Gatis
Published: May 2024

Up to 60% of Latvia’s energy resources are used as fuel for district heating systems. Heating sector is an important emitter of greenhouse gases – especially carbon dioxide. Therefore, reduction of carbon emissions of district heating systems are crucial in Latvia’s decarbonization efforts. One of the solutions is integration of energy hub in the district heating network. There are many types of energy hubs, and the most suitable solution must be found in each case. A goal of this study is to find the best solution for Latvia’s district heating systems to achieve decarbonization and use of green (renewable) hydrogen. This coincides with European Union’s plans to increase the use of green hydrogen not only in industrial and residential application, but in heat production as well.To facilitate the plans of the European Union and Latvia’s decarbonization needs a mathematical model made in Microsoft Excel is used as a method to explore the techno-economic aspects of the energy hub and its integration in the district heating system. Several alternatives are considered, and green hydrogen is used in all of those. Results show the economically most feasible alternative. Calculations are made on an annual term basis, considering such factors as electricity and district heating price, required capacity of electrolysis apparatus for hydrogen production etc.From the model some results are apparent – the price of electricity has a sizable impact on the economic feasibility of the project, and the best use for green hydrogen economics-wise may differ throughout the year as the price of electricity, hydrogen, district heating and methane gas change.
Adaptive Building Envelope Structures
Authors: Rudzite Lauma , Vamža Ilze , Vanaga Ruta
Published: May 2024

Climate changes which are increasing year by year are impacting not our environment but also our daily lives. One of the problems is the emission of greenhouse gases which are produced by householdings using heating fuel. Buildings in the Europe Union represents for 40% of energy consumption and 36% of greenhouse gas emissions. It’s very necessary to think about how to reduce consumption of energy and emissions. To design a strong building nowadays is very difficult and complex task, due to a growing to fulfil sustainability in the built environment, societal and economic performance requirements. Technologies, methods, and technical solutions are changing in building construction. More and more we have passive, active or net-zero buildings, and it’s the first step to reduce emissions in householding sector. Moving forward, adaptive building envelope structures which incorporates using biomimicry principles, are the next step to find solutions how to save energy and consumptions. Biomimicry teaches a way how to find and integrate the processes from nature and use them in research and design. The main goal is to identify physical characteristics of animal thermoregulation strategies such as fur, fats, vasoconstriction, and work harmony with the nature. For better results, it is important to collect all data, systemize, filter, and arrange it to create a database with the nature properties and technical information. After that the results shows the potential of a new adaptive building envelope structure database which can be used by environmental specialists, also other engineers as well as architects and civil engineers.
Validating ANSYS Heat Transfer Models Using Experimental Data Analysis of Two Phase Change Materials with Differing Melting Temperatures
Authors: Narbuts Jānis , Vanaga Ruta , Zundāns Zigmārs
Published: May 2024

Phase change materials are becoming more and more popular as viable options for improving the thermal performance and energy efficiency of a variety of applications, especially in innovative building envelope designs. In this paper, experimental data from two different phase change materials with differing melting temperatures (21°C and 28°C) are used to validate numerical system heat transfer models. The experimental setup included a heat flux apparatus, which was utilized to ascertain average temperature and heat flow changes over time during both heating and cooling phases for both phase change materials. The data obtained from the experiments were utilized to generate ANSYS Fluent simulation models replicating the experimental setup. The parameters and boundary conditions for the models can be assigned in several ways within ANSYS Fluent software. Consequently, two simulation models were created: one integrated the thermal and physical properties of the experimental setup's system components, while the other utilized the measured heat-flux values over time from the experiments as an input source for calculating average temperatures within the phase change material. The average temperature data from both simulation and experimental results were compared to validate both ANSYS models. By aligning the simulated results with the experimental data, the accuracy and reliability of the numerical models have been established in predicting the thermal behaviour of the two phase change materials. The two numerical system heat transfer models developed in this study serve as valuable tools for conducting further analysis and optimization of systems based on phase change materials. This research highlights the significance of phase change materials in enhancing the thermal performance of building envelopes, particularly in solar energy applications.
Life Cycle Assessment Framework for Diagnostic Imaging
Authors: Roletto Andrea , Savio Anna , Zanoni Simone
Published: May 2024

The increasing focus on environmental sustainability is becoming essential in the diagnostic imaging sector, which is accredited for about 10% of the healthcare industry’s carbon footprint. A multitude of research initiatives investigated the environmental impacts of diagnostic imaging, encompassing factors like electricity consumption, carbon emissions, and waste generation from these procedures. Life Cycle Assessment (LCA) stands as a prominent method for structural assessment of environmental impacts, offering a detailed framework for examining the environmental consequences of specific processes. The aim of this study includes analyzing existing LCA approaches in literature to identify their limitations and to suggest an elaborate framework for LCA application in diagnostic imaging.Out of 17 original articles on environmental sustainability in radiology published since 2014, but only a part, 29.4% (5/17), described an LCA approach. The different characteristics of these studies provide valuable insights, enabling the proposal of a more comprehensive LCA research methodology.The reviewed articles did not present a uniform research outcome. According to the GreenHouse Gas (GHG) Protocol Corporate Standard, the optimal outcome for assessing environmental impact is the calculation of greenhouse gas emissions. For a thorough methodological approach in LCA, it is essential to cover all direct and indirect emissions associated with diagnostic imaging. All studies (100%, 5/5) considered the electricity consumption of imaging equipment. Usage of consumables was included in 80% (4/5) of the studies. Only 40% (2/5) of articles considered auxiliary equipment like computers and contrast-medium injectors, as well as heating, ventilation and air conditioning (HVAC) systems. Factors like equipment manufacture, staff travel, and waste generation, though crucial to overall greenhouse gas emissions, were each covered in only 20% (1/5) of the studies. The articles also varied in their LCA versions, with two employing the detailed Cradle-to-Grave approach, while others used partial Cradle-to-Gate and Input-Output LCA methods.The insights from this analysis could lead to a valuable framework for a new LCA methodological approach in diagnostic imaging. This novel approach is designed to overcome the limitations observed in existing research, offering a more comprehensive analysis. By enhancing the LCA framework, it will be possible identify the phases in diagnostic imaging that have the most substantial environmental impact, allowing for the development of more targeted strategies to reduce GHG emissions associated with diagnostic procedures.
Challenges in Standardizing Global Emission Factors for Peatlands
Authors: Skujevska Dita , Feofilovs Maksims , Romagnoli Francesco
Published: May 2024

Peatlands have a crucial role in the global carbon cycle, acting as significant carbon sinks, but become a significant source of greenhouse gas (GHG) emissions when peat extraction is taking place. This article presents a comprehensive overview of peatland ecosystems, emphasizing their classification across various climatic zones and the complex set of different characteristics that determine contribution to GHG emissions. Currently, inconsistency exists in definition of emission factors used between countries leading to varied approaches in estimating peatland emissions and posing significant challenges in the comparison and aggregation of global data on peat extraction related GHG. The aim of the study is to analyse the disparities in emission factors and calculation methodologies employed by different countries. Data from national GHG emission reports are submitted under the UNFCCC and the Kyoto Protocol. Emissions report data calculations and emission factors can be based either on nationally determined data or on data specified in the IPCC guidelines. Consequently, emission factor data for four countries - Latvia, Finland, Sweden and Germany - are collected and processed, which were compared with IPCC guideline data. The data were compared in two ways: by equating units of measurement and by modeling. The results show there is a pronounced difference between the emission factors of each country, however, all these factors are lower than the maximum values specified in the IPCC guidelines. It was also determined that comparing the total emission factors with the modeled results, no significant difference is observed between these results.  The study concludes that emission factors are predetermined differently for each country, and it is not possible to specify the differences among assumptions for parameters included in the determination of the emission factors. The results suggest there is a need for development of more transparent accounting of emissions with regard to the diverse environmental and anthropogenic factors influencing peatland ecosystems. Factors like composition, depth of peat, water table levels, and local land-use practices further compound this variability in emission accounting. Addressing these challenges is crucial for enhancing the accuracy and reliability of GHG emission reporting under international frameworks like the United Nations Framework Convention on Climate Change and the Kyoto Protocol.
Assessing Environmental Impact: Organosolv Extraction of Cellulose Pulp from Wood Waste
Authors: Pazzaglia Aron , Castellanni Beatrice , Romagnoli Francesco
Published: May 2024

In the upcoming years, the paper industry is expected rely on containerboard for packaging, with approximately 80% of it being made from recycled fibers by 2020. Creating a new supply chain for fibers could help mitigate possible shortages. In this context, wood waste emerges as a valuable resource with the potential to serve as a plentiful and cost-effective reservoir for generating new materials, as cellulose fibers. This study presents an assessment of the environmental impact associated with the organosolv extraction of cellulose pulp from wood waste based on a previous in lab study conducted by the authors. The increasing demand for sustainable materials has prompted exploration into alternative methods for cellulose pulp production, with a focus on minimizing environmental footprint. Organosolv extraction, a promising technique, involves the use of organic solvents and acid catalysts to break down lignocellulosic biomass, resulting in high-quality cellulose pulp production. To evaluate the environmental implications of this process, a comprehensive life cycle assessment (LCA) approach was adopted. The LCA framework considers all stages of the organosolv extraction process, from wood waste collection to cellulose pulp manufacture, using a gate-to-gate approach. The functional unit for assessment is set as one ton of cellulose pulp. The dataset utilized for the LCA comprises primary data obtained from laboratory experiments, complemented by secondary data sourced from literature and the Ecoinvent life cycle inventory database. Furthermore, sensitivity analysis was conducted to assess the influence of key parameters on the environmental performance of the organosolv extraction process, with a focus on variations in energy consumption to identify potential areas for optimization and improvement. In summary, this study emphasizes the environmental aspects of utilizing organosolv extraction for cellulose pulp production from wood waste. Further research is warranted to explore energy consumption during the organosolv process for obtaining more precise data and optimizing the process. This could be achieved through pilot-scale experiments or utilizing process simulation software.
Carbon Footprint of a Nearly Zero Energy Building in Accra (Ghana): an LCA-based Model
Authors: Romagnoli Francesco , Rochas Claudio , Paoli Riccardo , Owusuansah Augustine , Odai Cornelius , Kobel Silvia
Published: May 2024

This study presents a comprehensive Life Cycle Assessment (LCA) of a Nearly Zero Energy Building (NZEB) in Accra, Ghana, comparing its environmental impact with a conventional Business-As-Usual (BAU) building over a 50-year lifespan. Adhering to ISO 14040 and ISO 14044 standards, the research evaluates the carbon footprint and operational efficiencies essential to sustainable building designs. Utilizing SimaPro 9.5 software and the IPCC 2021 GWP100 method, the total carbon footprint was quantified at 1727 tons of CO2-equivalent for the NZEB, significantly lower than the BAU comparison. The analysis highlights the operational phase, including waste generation as the most substantial contributor to the NZEB's environmental impact, accounting for 725 tons of CO2-equivalent emissions. Conversely, the strategic inclusion of solar panels and enhanced material selection for the NZEB markedly reduced energy demands, contributing to a net positive environmental outcome with an avoided carbon footprint of approximately -859.72 tons CO2-eq. This reduction underpins the NZEB's effectiveness in leveraging eco-friendly materials and renewable technologies, setting a benchmark for future sustainable construction practices. The study ultimately advocates for an integrated approach, harmonizing technological innovation with environmental stewardship, to mitigate the carbon footprint of the built environment, steering the construction industry towards sustainability.
Water-Energy-Food Nexus for Climate Change Mitigation in Jordan
Authors: Albatayneh Aiman
Published: May 2024

In Jordan, the struggle for survival hinges on balancing water, energy, and food security. This arid nation, acutely vulnerable to climate change, holds the Water- Energy- Food (WEF) Nexus approach - weaving water, energy, and food systems into a resilient tapestry. This Abstract delves into Jordan's intricate WEF Nexus, revealing a parched landscape dependent on groundwater, reliant on imported energy, and clinging to agriculture under a harsh sun. However, amidst these challenges lie glimmers of hope: existing initiatives addressing individual sectors and promising interventions leveraging the Nexus approach. The key to a sustainable future is scaling up renewable energy for desalination and efficiency, promoting climate-smart agriculture, and fostering regional resource management. Nevertheless, navigating this complex tapestry demands more than just interventions. Robust governance, empowered stakeholders, and active community engagement are the needles and threads that bind the WEF Nexus together, stitching Jordan's path toward a future where water, energy, and food security sing in harmony. Jordan's narrative is not just about climate vulnerability but about resilience. By embracing the WEF Nexus and its inherent interconnectedness, this nation can transform itself from a thirsty landscape into a beacon of hope, showcasing how climate resilience can develop even in arid regions
Enzymatic Activity of Fungi for Hydrolysis of Wheat Bran and Cultivation of Oleaginous Yeasts
Authors: Conti Fosca , Pilz Melania , Castellan Nicolo , Qoura Farrah , Brück Thomas
Published: May 2024

Sustainable alternatives to petrochemical raw materials in oleochemical, laundry detergent and personal care industry need to be implemented. Presently, palm oil is the predominant cost-efficient option. While it is a renewable source, it has negative environmental and socioeconomic implications.  Therefore, the request for ecologically certified and palm oil-free cleaning agents and household care products is rapidly growing, supported by concepts of waste-free biorefinery. Oleaginous yeasts are currently the most promising source for microbial lipid production. Additionally, wheat bran is a cereal milling by-product, which is available in high quantities and provides an excellent feedstock. Enzymatically generated wheat bran hydrolysate provides an excellent microbial cultivation medium for the sustainable production of high value biological additives. Indeed, wheat bran consists predominantly of lignocellulose, and therefore of cellulose, hemicellulose and lignin, which can be hydrolyzed by established enzyme systems. Currently, such enzymatic systems are mainly obtained for the market from genetically modified organisms (GMO). This represents a problem because GMO products or process components cannot be included in eco-certified household care formulations. Therefore, innovative GMO-free biotechnological processes need to be implemented, as well as the isolation of novel GMO-free hydrolase enzyme systems. Fungal strains are an interesting source for the efficient screening and isolation GMO-free hydrolases (see figure).This contribution is part of a project, which aims to use a holistic biotechnological approach to convert mill residues into customized specialty ingredients of eco-certified detergents. The project focuses on three main tasks:investigation of a microbial group of eight Ascomycete fungi,production of enzymes for hydrolysis of wheat bran, anduse of the resulting biomass hydrolysate to cultivate oleaginous yeasts.Hydrolase producing fungal strains were cultivated on different substrates to investigate their ability to generate specific enzyme systems capable of hydrolyzing wheat bran. The activity of the enzymes was qualitatively and quantitatively characterized to determine the optimal strains for the degradation of wheat bran and suited to implement a large-scale process. Supernatants of different fungal strains cultivations were tested in the hydrolysis step to compare the hydrolysis performances of differently active enzyme mixes. The biomass hydrolysate was used to cultivate lipid generating yeasts to investigate their ability to grow on the microbial cultivation medium.
Assessing the Feasibility of Climate Policies of Japan, Latvia and Lithuania to Reach the Targets of the Paris Agreement
Authors: Sabūnas Audrius
Published: May 2024

The study compares the most recent developments in energy policies of Japan, Lithuania and Latvia as a way to mitigate climate change. Latvia, Lithuania and Japan have all pledged to reach net zero by 2050 but face significant challenges, namely the dependence on energy imports in the form of fossil fuels, as they keep dominating the final energy supply. All three countries have a goal to sharply reduce this dependence, with Lithuania and Latvia even striving to become net energy exporters by focusing almost entirely on renewable energy. Japan, on the other hand, also aim to boost a renewable energy share, yet focuses more on the diversification of imported energy sources. The study attempts to discuss the differing approaches in climate change mitigation in Japan as compared to Latvia and Lithuania. The ambition of each country is estimated by Intended Nationally Determined Contributions (INDCs), the roadmap to reduce the emissions in different sectors as enshrined in the climate strategy of each country, and the penetration of the renewable energy sector, estimating the scope of the ambition and implementation gaps compared to the goals set by the Paris Agreement. The study also estimates the impact of external impacts, namely the COVID-19 pandemic and the Russian invasion of Ukraine in shaping climate change policies. Therefore, this study offers a comprehensive outlook on what needs to be achieved so that all three countries could be role models to follow in the climate policy. All three countries could collaborate on solar power, off-shore wind power, and hydrogen technologies. There have already been joint projects between Japan and the EU on advanced biofuels and the new generation of concentrator photovoltaics. However, there are significant differences regarding the role of ammonia and hydrogen production in the Climate change policy strategies of the three countries. Some contributing sectors are left behind and the current climate change strategies, even if properly implemented, may not be 2°C-compatible, let alone 1.5°C-compatible. The policies look even direr for a fair share target, and the implementation gap generally remains wide for the 2024-2030 period.
Use of Solar Energy to Increase the Sustainability of Shared Micromobility
Authors: Rubenis Aivars , Celms Armands , Adrian Leslie
Published: May 2024

This study continues the examination of potential ways to decrease greenhouse gas (GHG) emissions in the urban transportation sector by using shared scooters in Riga. Despite claims by shared scooter operators that these vehicles are environmentally friendly, shared e-scooters contribute an additional 239.9 tonnes of CO2 in Riga. While energy is not the largest source of CO2 emissions for shared scooters, it is one factor that could be improved by switching to locally produced green energy. This study revaluates the CO2 emissions from shared scooters based on an additional year of data. It also analyses the possibility of generating enough energy on-site to provide chargers with PV energy.For this purpose, the study utilizes the last seven years of solar energy data in Latvia to model the potential energy flows that can be used to charge the electric scooters. This data is then combined with information from 3 million scooter trips from the 2021-2022 scooter seasons, analysing the trips and the energy used during scooter use. It was determined that, on average, 59.6Wh were used per trip, with a standard deviation of 18.9 Wh. The model was tested with various levels of PV cell areas and energy storage systems to determine the minimum parameters required for the scooters to be provided with enough energy without the need for additional grid charging.The results demonstrate that it is indeed possible to provide enough solar energy to ensure continuous charging of the electric scooters for 98.8% of the cases during the scooter operation period with just 0.2m² of solar cells per scooter. In conclusion, while this approach does not completely offset the CO2 emissions generated by the short scooter lifespan, it is a step towards greener urban transport. Further research will be carried out to optimize the charging locations for the evaluation of practical PV charging viability.
A Preliminary Evaluation of Alternative Raw Materials for Pellet Production
Authors: Priedniece Vivita , Sturmane Amanda , Eglitis Raivis , Juhnevica Inna , Krigers Guntars , Kirsanovs Vladimirs
Published: May 2024

The study focuses on alternative raw materials available in Latvia and their possible use in pellet production. Laboratory testing to determine the main quality parameters – the moisture content, the ash content, the calorific value and ash melting temperature – was carried out for 13 alternative biomass sources: pine mix pellets (PMP); pellets of wood shavings, synthetic and textile waste mix (SSK); hogweed (Heracleum sosnowsky, HW); the full plant of Solidago canadensis L. (SC); the full plant of Solidago canadensis L. outgrown (SCO); mowed grass from the municipality (MGM); mowed grass from the garden (MGG); chamomile full plant without stems (CF); hemp without roots (Cannabis sativa L., HWR); hemp stems (Cannabis sativa L., HS); hemp leaves with seeds (Cannabis sativa L., HLS); spent grain (SG); damaged spent grain (DSG). The testing and determination of results were carried out according to the methodology set out in ISO standards regarding solid biofuels. The obtained results were compared to the quality parameters defined in ENplus certification for B-class wood pellets in requirements for producers. Additional analysis of chemical composition was carried out using XRD (X-ray diffraction) and SEM-EDX (scanning electron microscopy - energy dispersive X-ray spectroscopy) for the ash of two selected materials - SC and HLS - to gain an insight into possible combustion issues that can occur during the use of these materials. The main issue highlighted by the results is the ash content of alternative materials, which ranges from 1.34% to 11.27%. The other significant issue is the necessity to improve the ash deformation temperature, which was below 1100°C for 5 of the studied materials. Considering this, an algorithm was developed to determine the optimal proportion of alternative material and wood in pellets to achieve a quality comparable to at least B-class wood pellets. The study offers a direction for further research to successfully develop new pellets that could be later used in existing boiler systems, reducing the dependence on wood in pellet production. A discussion on the use, quality and development of alternative material pellets is offered to promote the significance of the topic.
Exploring the Potential of Renewable Energy to Enable Green Hydrogen Production for a Sustainable Future
Authors: Patel Kunj Nilesh , Patel Yagna Bhupendra , Nagababu Garlapati
Published: May 2024

Abstract – Amidst intensifying concerns about greenhouse gas emissions, the imperative to transition towards sustainable energy solutions is paramount. Renewable energy sources (RES) provide a promising avenue, especially in hydrogen production. In this context, the emergence of “green hydrogen” is pivotal. Green hydrogen is a concept produced using RES like solar and wind energy to power the hydrogen production process. Unlike conventional methods emitting carbon dioxide, green hydrogen is generated through water electrolysis using clean energy. India relies on coal for around 70% of its energy needs, leading to a 29% rise in carbon emissions from 2015 to 2022. Green hydrogen is a potential alternative solution to address the increasing energy demand and the depletion of fossil fuels. Using wind energy for water electrolysis emerges as a suitable method for green hydrogen production. Therefore, in the present study, assessed the potential of hydrogen production using the wind energy resources in five selected locations in India using ERA5 hourly wind data. The investigation further explored the characteristics of wind speeds at these locations using average wind speed, Weibull parameters and wind rose analysis. Using the SUZLON S95 wind turbine, power output and annual energy generation at each location were estimated. Further, estimated the annual hydrogen production and required storage capacity at each location. The results showed a power generation of 891 kW in location Una and 895 kW in Mandvi. Finally, the amount of carbon emissions mitigated due to the use of wind energy sources instead of conventional sources for H2 production is calculated.
Current Trends and Solutions for Port Decarbonisation: A Systematic Literature Review
Authors: Kļaviņš Aivis , Kirsanovs Vladimirs , Pakere Ieva
Published: May 2024

The energy sector is changing rapidly today. Global warming and other environmental challenges contributed to several international agreements aimed at fostering fossil-to-renewables debt. Decarbonization is undoubtedly a challenge, but at the same time a potential for development. The energy sector is made up of many sectors that have their own specificities, constraints, and opportunities. This study reflects progress in the decoration of ports. Ports are a place that often brings together energy consumers of different levels and types – water and land transport, as well as consumers of thermal energy, electricity, and fuels. The bibliometric analysis method is used at publication to analyze current trends. The results show that despite the existing challenges and historic delays with the entry of renewable energy sources into ports, scientific progress is prepared to offer solutions to decarbonise port energy consumers as well. These studies reflect that hydrogen technologies are the most prospective solution, but many aspects and links need to be considered to ensure the transformation of the sector.
Challenges of Undular Jump Modelling
Authors: Nowak Petr , Bilkova Eva , Halych Oksana , Riabenko Oleksandr
Published: May 2024

The study of open channel flow hydraulics extends beyond supercritical and subcritical flow states to include a distinct state known as near-critical flows. This category encompasses various hydraulic phenomena, with some of the most notable being solitary waves, cnoidal waves, and undular jumps. This paper specifically addresses the phenomenon of undular jumps, providing a brief overview of its characteristics and discussing instances of undular jump formation in natural rivers settings and during the operation of various hydraulic structures. When there is a sudden change in flow depth from a lower level to a higher one, it typically leads to a sudden increase in the water surface, known as a hydraulic jump. However, if the jump is relatively small, meaning the depth change is minor, the water does not rise noticeably and abruptly. Instead, it will traverse from the lower to the higher stage through a sequence of gradually diminishing undulations that extend over a considerable distance. Such phenomenon is called an undular jump.The occurrence of undular hydraulic jumps can be observed in various open channels such as irrigation and water supply channels, beneath vertical sluice gates, within estuaries during specific tide periods, and in narrow or shallow passages affected by strong currents. Additionally, this phenomenon often manifests downstream of low drop structures or in transitional zones from steep to gently sloping channels. In channels where undular jumps occur, waves with significant amplitudes develop and travel downstream of the jump. Accounting for the propagation of these downstream free-surface waves is essential for canal design and natural channel maintenance. The wave height serves as a crucial design parameter that dictates the necessary sidewall height of the canal. In natural channels, the embankment height must exceed the crest of the free-surface undulations to prevent overtopping and subsequent erosion, which could ultimately lead to bank destruction. Moreover, the propagation of free-surface waves may subject downstream canal structures, such as gates, locks, and weirs, to additional impact loads, perturbations, and vibrations.In recent years, different scientists have made various attempts to investigate and describe this phenomenon using physical, mathematical and computer modelling. However, this phenomenon has a number of peculiarities that are not always taken into account. An objective of this article is to present the particularities of different type of undular jump modelling and to compare the obtain results.
PH-Optimized Biomethane Production: Evaluating Carrier Materials for Ex-situ Biomethanation
Authors: Kusnere Zane , Laipniece Lauma , Spalvins Kriss
Published: May 2024

Choosing the appropriate carrier material for ex-situ biomethanation is a critical factor to consider when developing biogas upgrading technologies. The chosen material for biomethanation in a biotrickling filter reactor functions as a substrate that immobilises microorganisms, which act as catalysts in the reaction for producing biomethane. This study conducted experiments on waste-derived materials, including glass foam and vulcanised wood ash material, in addition to polyurethane foam and expanded clay pellets. Pretreratment of wood ash was done to lower the pH of material. The manometric test measured the rate of CH4 generation by quantifying pressure fluctuations. The validity of these results was confirmed by analysing product gas samples using a Shimadzu Nexis GC-2030 gas chromatograph, which was equipped with two parallel lines, a flame ionisation detector (FID) and a thermal conductivity detector (TCD). In order to enhance the biomethane concentration in the end product, two strains of Methanobacterium alcaliphilum were evaluated alongside biogas sludge as the inoculum. These strains of microorganisms are methanogens that utilise hydrogen and can thrive in a high pH environment. Thus, they have the potential to demonstrate improved biomethane production outcomes when a vulcanised wood ash filter is used as the carrier material.
Green Wheels, Greener Wallets: Economic Viability of Last-Mile Delivery Fleet Electrification in Case of Latvia
Authors: Scedrovs Aleksandrs , Mendzins Karlis , Feofilovs Maksims
Published: May 2024

The analysis of internal combustion engine vehicle (ICEV) usage habits in the DPD Latvija company and the study of the specifics of its last-mile delivery transport business will allow to understand whether electromobility solutions can make the company more efficient. The question addressed in the research is whether the electrification of the delivery vehicle fleet can reduce transport expenses for the company and under what conditions. For estimation of direct and indirect costs of transport acquisition and usage Total Cost of Ownership (TCO) is used. The company’s daily operation parameters and technical data of the used vehicles VW e-Crafter and VW Crafter 35 Kasten/long base are considered in the study. Net Present Value (NPV) and Internal Rate of Return (IRR) calculation methods are used for analyzing the investment project. The expense of the creation of electrical vehicle charging infrastructure is not considered, because the company’s daily routine allows to cover all charging processes overnight by using domestic sockets together with Mode 2 chargers. All technical data and calculations were made for deliveries in a city cycle. In financial terms of owning delivery transport, the company is using a 5-year operational lease with 0% first payment. The obtained results in terms of TCO comparison showed a slight advantage by using EV after 5 years of last-mile delivery service per 1 vehicle – 706.98 Euro at 31200km a year or 100km in the working day of 6-day working week (156000km in 5-year is under 160000 warranty condition). The calculation is performed for DPD Latvija 213 ICE vans of a total 240-vehicle fleet. Results of NPV, NPVI, and IRR with a comparison rate of 10.6% for EV case clearly show a sufficiently good return. The Net Present Value of the solution is 89271.92 Euro and the Internal rate of return is 48.05%. The study proves that the electrification of the last-mile delivery company's fleet is economically justified and within 5 years. In the process of electrification, the company will reduce its expenses – by 1.45%, which increases the net annual profit by 0.13%. The main conclusion is that the company will not incur losses by switching to an environmentally friendly vehicle, the capital investment in a realistic scenario pays off already from the 3rd year. Nevertheless, the authors of the study recommend evaluating delivery vehicles with higher driving range parameters, because during peak delivery and seasons with cold weather, the company may experience unplanned downtime and expenses due to the need for additional charging time at public charging networks on the road, that could lead to financial losses and need for TCO calculation corrections.