bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow simulation of self-consolidating concrete through V-funnel for sustainable buildings
Authors: Onyelowe K C , Kontoni D-P N , Ebid A M 
Published: December 2022

Abstract
Self-consolidating concrete (SCC) is one of the trending low-yield stress material innovations of the new age building industry due to its ability to flow through heavily reinforced structural members without segregation and without losing its moderate viscosity. In this research paper, a V-funnel simulation has been developed for the flow time to establish its validity with allowable design conditions according to the European standard. The Bernoulli’s equation and the continuity flow state conditions were adopted for the V-funnel of 515 mm upper width, 75 mm thick, and vertical dimensions (depth) of 450 mm and 150 mm for the V-section and funnel duct (75 mm × 65 mm) respectively. Concrete shear stress with the funnel wall was considered as a factor of concrete unit weight (ρ) and frictional force under downward velocity with respect to variational height (dh). The result of the V-funnel simulation for the flow time shows that the kinematic viscosity (η) of the concrete is bound within the limits of 0 and 1/64. This implies that ηmin ≈ 0 (no friction with walls), and the minimum flow time (Tmin) becomes 8.7 sec while minimum shear stress is zero (τmin ≈ 0 N/m2). However, for ηmax ≈ 1/64 (maximum friction with walls of τmax τ ρ/64 N/m2 is attained) and Tmax becomes 18.9 sec. These values fall within the flow time after 10 seconds of mixing, ranging between 8 and 10 seconds, and the flow time after 5 minutes of mixing of 11 to 25 seconds, according to the European Guidelines for self-consolidating concrete. These results for the flow simulation of the concrete placement during construction, are also consistent with the United Nations sustainable development goals (SDGs) for technological innovation, infrastructure, and sustainable cities.
Energy consumption in Greek school buildings as a function of the climate zone
Authors: Karali I , Giannarou S , Zervas E 
Published: December 2022

Abstract
In this study, the condition of school buildings throughout the Greek territory was analysed, with reference to the typology of the buildings and consequently to the date and the method of construction. Emphasis was placed on the importance of the schoolyard both for the educational process and for the psychology of the students and the contribution to the improvement of thermal comfort conditions in the school premises and in the wider area. The purpose of this study is to investigate the energy status of school buildings that have been energy upgraded in all 4 Climate Zones of Greece by collecting data on energy consumption, construction date, construction method, educational level, and interventions. The research was based on questionnaires completed by users of school buildings to capture the reality of thermal comfort, air quality and energy efficiency after the interventions. Thus, considering the specific climatic conditions of each region, useful conclusions are drawn regarding the efficiency of the interventions and the actions required achieving real energy efficiency. After all, according to an EU directive, public buildings must be converted into zero-energy buildings.
The future of public transport in the era of sharing economy: the view of transport operators
Authors: Gouni Varvara , Kehagia Fotini , Nalmpantis Dimitrios 
Published: December 2022

Abstract
The purpose of this paper is to examine the new landscape that is being formed for urban public transport in the new age of the sharing economy. In this paper, the evolution of shared mobility systems is examined through a literature review and the way that this trend is shaping the landscape of urban public transportation. Moreover, through a questionnaire survey amongst public transportation experts, the megatrends that are formed among public transport operators are examined, i.e., in which way they will respond to the new reality, e.g., will they take a competing or a collaborative stance, and how the modal split will be affected? Twenty-two (22) public transport experts from all over the world participated in the survey. It was found that carsharing and autonomous vehicles will positively affect the demand for urban public transport. Nevertheless, it was found that autonomous cars without carsharing will not have the desired results on demand for urban public transport, a finding that is crucial! Moreover, the experts seem to be very positive about public transport operators offering carsharing and autonomous vehicle services by their own means. The results were analyzed with the use of independent samples t-test and ANOVA.
“Transforming a power plant into an Educational Centre: Agia Small Hydroelectric Power Plant”
Authors: Bourbourakis Panagiotis J. , Tsikalakis Georgios J. 
Published: December 2022

Abstract
Renewable Energy Sources (RES) is the spearhead of the current global energy and technological market. However, RES has been part of our everyday life for many decades. Hydroelectric energy, the prime of the RES’s, had a pioneer presence at the non-interconnected island of Crete, where the Small Hydroelectric Power Plant (SHPP) of Agia ceased its operation after eighty years of service. Subsequently, the owner of the plant decided to grant the permission of use of the plant facilities to the Prefecture of Crete and to finance the renovation of the facilities, towards the design and erection of a museum and information center for the Renewable Energy Sources, for the Culture of Water and for the promotion of “acting green”. Furthermore, the information center, combined with the amazing natural environment and adjacent ecosystem of Lake Agia, create a sightseeing of high educational and ecological interest. In the project, we highlight a good example of utilizing the infrastructure and facilities of a past Renewable Energy Sources Power Plant and transforming it into an Educational Centre, focusing on environmental sustainability and education.
Road investment and safety in middle- and high-income countries in the framework of sustainability
Authors: Kehagia F , Giannaki M 
Published: December 2022

Abstract
The rise of economic growth and transport activities worldwide has led to an increase in reliance on vehicles. However, transport activities are associated with several negative impacts, with road safety being a major environmental-societal issue. The main aim of this study is to investigate a possible relationship between investment in road infrastructure and mortality rate due to road accidents. To assess the economic resources invested in roads, the analysis was conducted in two separate groups: middle-income and high-income countries. World Road Statistics 2017, IRF, period 2010-2015, provided data for the analysis of the impact of the economic resources invested in roads, expressed in specific indicators on road casualties. Mortality rate was used as the dependent variable, while the independent variables were: percentage of paved roads, density of the total road network, and proportion of highways. The parameter of economic resources invested in roads is expressed indirectly by the categorization of the middle- and high-income of the countries. In middle-income countries, the provision of a road network increases mobility, and thus the exposure to risk and the possibility of a road accident increases. In high-income countries, the highway network has a significant impact on reducing road accident mortality rate.
Simulation of self-compacting concrete (SCC) passing ability using the L-box model for sustainable buildings
Authors: Onyelowe K C , Kontoni D-P N , Ebid A M 
Published: December 2022

AbstractThe self-compacting concrete (SCC), which is the major innovation of the concrete technology of the 21stcentury, has been sustained due to its impact on the sustainable construction of infrastructures. Various additives have been coupled into the production of SCC to improve its passing ability, flow, shear stress, dynamic resistance and segregation resistance. The flow of the SCC is experimentally measured through various models, which include Slump-cone, V-funnel, L-box, U-box, J-ring, etc., by which the flowability, passing ratio (passing ability), etc., are determined. In this research paper, the L-box model has been used to simulate the flow output condition, which is the passing ratio (h2/h1) of the SCC, to optimize its passing ability for sustainable concreting. The passing ability of the SCC through the L-box was estimated by recording the heights at the upstream (h1) and downstream (h2) of the horizontal leg of the test box at the end of the flow through embedded steel bars. Stress and pressure boundary conditions for the flow state condition were deployed to solve the passing ratio simulation problem for the L-box model. The results show that the optimized passing ratio (flow output), h2/h1, falls within the appropriate European Guidelines for Self-Compacting Concrete (SCC) materials.
External cost of pollutant emissions in Turkey
Authors: Büke T , Köne A Ç 
Published: December 2022

Abstract
External costs that occur in the use of energy resources are one of the most important criteria in determining energy and environmental policies. For this purpose, it is important to know the external costs of any energy sources. The purpose of this study is to calculate external costs due to air pollutants in Turkey for the years 2000 and 2019. The air pollutants namely ammonia, nonmethane volatile organic compounds, nitrogen oxides, particulate matter, and sulphur dioxide have been taken into consideration in the evaluation for the impact categories-human health damage, loss of biodiversity, crop losses, and buildings damaged. These pollutant emissions data were obtained from the European Environmental Agency database. Then, these pollutant emissions data were used in the monetization calculations for the years 2000 and 2019. According to the evaluation, air pollutant emissions’ total external costs in Turkey were 25135,72 Million Euros and 24654,42 Million Euros for the years 2000 and 2019 respectively.
Barometric Pressure as a correction factor for low-cost particulate matter sensors
Authors: Christakis I. , Moutzouris K. , Tsakiridis O. , Stavrakas I. 
Published: December 2022

Abstract
Concentration of particulate matter constitutes a major, environmental problem affecting human health especially in urban areas. Although research centers and government agencies have air quality monitoring systems installed, their limited number prevents the spatiotemporal analysis in urban areas. EU funds research projects to engage citizens for air quality issues. The aim is to involve citizens to install low-cost air quality measuring stations to develop a wider network and to retrieve accurate information about air quality. The use of low-cost sensors arise questions about the reliability of the measurements. It is known, that particles concentration measurement are affected by humidity and temperature. Several models have been proposed to remove the impact of the temperature and humidity on the particle’s measurements but the impact of barometric pressure is under investigation. In this work, an extensive study is performed on the barometric pressure aftermath and corrective factors are proposed in relation to it. The pilot stations were installed next to high cost official stations for a month to calibrate the low-cost sensors. Herein, a model of multiple linear regression is presented to confirm the importance of barometric pressure correction, with the ultimate goal being the optimization of the low-cost particle sensors measured values.
Modelling of NMVOC emissions from solvents use in Greece
Authors: Sebos I , Kallinikos L E 
Published: December 2022

Abstract
The use of solvents and other volatile organic chemicals is a significant source of Non-Methane Volatile Organic Compounds (NMVOCs) emissions. Due to the wide spectrum of applications of solvents and numerous locations where these occur, the estimation of NMVOCs emissions can be challenging. The aim of this paper is to present the methodological framework used in Greece for the estimation of NMVOCs emissions. It covers processes and products that use solvents and other volatile organic chemicals in several industries, as well as in households. The framework is based both on existing methods found in the literature and on new emission factors developed in order to reflect the mitigation potential of EU Directives and national legislation aiming at the reduction of NMVOCs emissions. The developed framework was verified by comparing it with solvent emission estimates from the European Solvent Industry Group.
The application of the Bow Tie approach in the risk assessment of a municipal solid waste management system
Authors: Georgousoglou K , Mouzakitis Y , Adamides E D 
Published: December 2022

Abstract
Effective municipal solid waste management requires rigorous risk assessment, evaluation and monitoring through a risk management system. In this line, this study aims first to highlight the importance of using the Bow Tie risk analysis method as a quantitative analysis tool for optimal waste management, and second to demonstrate the fact that the reliability of the method’s results, depends entirely on the uncertainty inherent in the various estimates of the stakeholders. Methodologically the work is based on two pillars: first, a study of the existing literature on risk management in the context of waste management is undertaken, and second, a bow-tie type risk analysis model is developed. Towards this end, and building on previous work, we concentrate on the highest impact event / hazard, identified in the existing municipal waste management system of the Municipality of Patra, Greece, and we apply the Bow Tie type analysis method in order to re-estimate its risk. This method’s results are then subjected to statistical and sensitivity analysis using Monte Carlo simulation to ensure the reliability of the results. Overall, the impacts of the most important risk are presented, and the advantages of the method are highlighted.
The impact of solids retention time on Greenhouse Gases Emissions from biological wastewater treatment processes
Authors: Kemmou Liana , Samiotis Georgios , Ristanis Ilias , Amanatidou Elisavet 
Published: December 2022

Abstract
Biological wastewater treatment is linked to direct and indirect greenhouse gases (GHGs) emissions, thus new approaches on design and operation of wastewater treatment plants (WWTPs) must be adopted aiming towards GHGs emissions’ mitigation. This study evaluates the impact of solids retention time (SRT) on GHGs (CO2 and N2O) emissions of activated sludge (AS) wastewater treatment processes with nutrients removal operating at 10, 30 and 180 days SRT. The 180 days SRT represents the complete solids retention AS process (CRAS), which introduces a novel WWTP design and operation approach for excess sludge reduction. The evaluation of GHGs emissions and process performance via ASDM model and Bridle methodology showed that the total N2O emissions increased together with increasing dissolved oxygen and SRT. CRAS process achieved 97,4% and 96,2% excess sludge reduction compared to AS process with SRT of 10 d and 30 d respectively, with total direct emissions in CRAS process being respectively higher by 20,0% and 12,2%. The lower total indirect emissions in CRAS process compensate for the higher direct emissions. At high influent loads, the balance in GHGs emissions tilts in favour of CRAS process due to management of increased excess sludge quantities, rendering CRAS process a more sustainable choice.
Investigation of the particulate air pollution and the ratio of PM2.5 to PM10 concentrations in the atmosphere over the lignite mining and lignite-fired power plants region of Western Macedonia, Greece.
Authors: Evagelopoulos V , Begou P , Kassomenos P , Zoras S 
Published: December 2022

Abstract
The lignite long-lasting exploitation has resulted in a series of negative impacts on the air quality of the lignite basin of Ptolemaida, Amynteo and Florina. The coal-fired plants in this region are the greatest sources of air pollutants, such as SO2, NOX, CO2, PM, heavy metals and fly ash. In this study, we investigate the air quality of Western Macedonia based on measurements of PM2.5 and PM10 in ten air quality monitoring stations (Filotas, Koilada, Oikismos, Petrana, Komi, Amyntaio, Florina, Vevi-Meliti, Pontokomi and Anargyroi) which are located in the broader area of the lignite power plants. The trends of PM time series over a 12-year period (2010-2021) show a gradual decrease of PM2.5 and PM10 concentrations following the decline of lignite production in Greece. In order to characterize the underlying atmospheric and anthropogenic processes affecting the PM concentrations we assessed the ratios of PM2.5 to PM10. The high ratios of PM2.5/PM10 indicate a major contribution of fine particles attributable to anthropogenic air pollution sources, while small ratios indicate that coarse particles are dominant, which might be related to natural sources of air pollution. We found that average PM2.5/PM10 ratios during the study period ranged between 0.48 in Oikismos and 0.70 in Florina and Vevi-Meliti. For Florina and Vevi-Meliti, the daily PM2.5/PM10 ratios were found to reach the value of 1.0, while the daily average ratios of PM2.5/PM10 were above 0.9 for almost the 15 % of the days in these sites. In the other sites high daily ratios of PM2.5/PM10 were found for a lesser number of days. The high ratios which have been found at these sites indicate the considerable contribution of energy combustion for heating purposes and other anthropogenic processes. Overall, we used the PM2.5/PM10 ratio to characterize the processes affecting the air quality within the local environment.
Photocatalytic treatment of metronidazole-containing wastewater
Authors: Abdirova Perizat , Kanafin Yerkanat N. , Poulopoulos Stavros G. 
Published: December 2022

Abstract
The presence of antibiotics in wastewater is risky for the environment as the conventional wastewater treatment plants are not always capable of removing them completely. Therefore, antibiotics may enter the water bodies and affect the health of aquatic living organisms. In this work, the effluent after the continuous flow activated sludge process was collected and analyzed. The average total organic carbon (TOC) and metronidazole (MNZ) concentrations were 43 ± 13.1 mg/L and 5.3 ± 0.2 mg/L, respectively. The catalytic activities of TiO, TiO2, Bi2O3, and WO3 were tested under the visible light (VIS, 500 nm) and near-visible ultraviolet light (UV, 365 nm) irradiations. The structure and properties of the catalysts have been verified using SEM-EDX and Mastersizer 3000. 25% of MNZ have been degraded under VIS only after 150 min. Even though all four catalysts were able to degrade MNZ to some extent (28-33%) after 150 min of VIS irradiation, they were not able to mineralize the organic compounds of the wastewater. On the other hand, the application of UV alone and with the catalysts resulted in the complete degradation of MNZ. Moreover, UV/TiO2 achieved 52% TOC removal after 150 min of the experiment.
Optimization of the remediation of oil-drilling cuttings by combining artificial neural networks with knowledge-based models
Authors: Kalari K , Christodoulis K F , Nikolakopoulou D , Bali N , Theodoropoulou M , Economou P , Tsakiroglou C D 
Published: December 2022

Abstract
In the present study, a feed-forward dense multilayer artificial neural network (ANN) trained with backpropagation algorithm (BP) is used to determine the kinetic parameters governing the performance of the oil-drilling cuttings (ODC) ozonation. Ozonation tests of ODC, pre-treated with surfactant (SDS) and diluted with synthetic seawater, are conducted on a semi-batch bubble flow reactor. The performance of ozonation experiments on semi-batch bubble flow reactors is evaluated by measuring the removal efficiency of the total organic carbon (TOC). The experimental datasets are employed to calibrate two mathematical models of increasing complexity: a tank-in-series (TSM), and a computational fluid dynamics (CFM) model, both combining multiphase transport with reactive processes, involving a high number of unknown parameters, and being able to provide numerous simulated datasets for various values of dimensionless parameters. These data are employed for the training and validation of the neural network. The trained neural network is then interpreted through the Shapley additive explanation (SHAP) method to provide insights about the experimental parameters.
Predicting Coastal Dissolved Oxygen Values with the Use of Artificial Neural Networks: A Case Study for Cyprus
Authors: Hadjisolomou E , Antoniadis K , Vasiliades L , Rousou M , Thasitis I , Abualhaija R , Herodotou H , Michaelides M , Kyriakides I 
Published: December 2022

Abstract
Coastal hypoxia is a serious environmental problem that needs to be addressed at a global level. The phenomenon of hypoxia is characterized by low Dissolved Oxygen (DO) levels in the water column that causes detrimental effects on aquatic organisms. Anthropogenic activities such as intensive agriculture practices and point-source nutrient loading are considered the main causes of coastal hypoxia. This study utilizes data-driven modelling based on Artificial Neural Networks (ANNs), and specifically Feed-Forward ANNs, to predict surface DO levels. Several surface water quality parameters such as water temperature, nitrogen species (ammonium, nitrite and nitrate), phosphorus, pH, salinity, electrical conductivity, and chlorophyll-a served as the ANN’s input parameters. These parameters were measured at several sampling sites in the coastal waters of Cyprus and some of the sites were located near areas with anthropogenic activities, during the period 2000-2021. An ANN with a 9-5-1 topology was developed and ANN managed to predict with good accuracy the DO levels, with the Coefficient of determination (r
2) as high as r
2=0.991 for the test set. Additionally, sensitivity analysis was performed to measure the impact of each input parameter on the DO level, and it was estimated that the water temperature is the most influential factor. The “Weights” sensitivity analysis algorithm was used for this purpose. The ANN-based method proposed can be used as a management tool for predicting the DO levels and prevention of hypoxia. Therefore, this work has a positive impact on marine sciences and marine information technology.
Valuing Natural Ecosystems: The Case of National Park Kotychi-Strofilia in Peloponnese, Greece
Authors: Dimopoulos V. , Tourkolias C. , Mirasgedis S. 
Published: December 2022

Abstract
Ecosystem services are among the environmental goods that are not directly included in the market mechanism, hindering their integration in the framework of cost-benefit analysis. To fill this gap, environmental valuation techniques can provide useful insights as regards the economic value of ecosystems, facilitating their integration in decision-making processes. The present work values an extremely sensitive and protected ecosystem in the Southern Peloponnese, namely the National Park of Waterfalls of Kotychi – Strofilia, which comprises one of the largest pine forests in Europe (Strofilia) and several important wetlands and lagoons (Kotychi). The Contingent Valuation Method (CVM) has been implemented for valuing the ecosystem services of the park in question and depicting how the results of the analysis can be used for decision making. The analysis was supported by a survey of the residents of the wider area, through the completion of an appropriately designed questionnaire, with a view to estimate the expenditures that are socially acceptable to be allocated for its restoration and protection. The results showed that the mean willingness to pay per household to protect the national park under consideration ranges between 5.5-9.5 EURs/semester for a period of 4 years, leading to a total value of the ecosystems in question of 14.7-25.5 million EURs.