Periodica Polytechnica (Budapest University of Technology and Economics)
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Evaluating the Sustainability of Metro and Feeder Bus Integration: A Bengaluru Metro Case Study in India
Get PDFRapid urbanization and an increase in private vehicle ownership in India's major cities have contributed to increased traffic congestion, pollution, and accidents. These challenges could be addressed in part by encouraging commuters to use public transport instead of private vehicles. The integration of different transport systems would be essential for increasing the utilization and efficiency of public transportation. It is essential to evaluate the existing level of integration among various transport systems to improve it. Consequently, the objective of this research is to adapt a methodology for evaluating the existing level of integration between metro and feeder buses while keeping sustainability as a goal. For evaluation, 18 sustainable transportation indicators were considered. To estimate the Sustainability Integration Index (SII) value, data were collected from transport hubs and nearby bus stops in Bengaluru, India. The multi-criteria method was used for the homogenization of transportation indicators. Based on the expert opinion survey, additional appropriate weights were obtained for each indicator, and the final SII value for selected metro stations was estimated in the range of 0 to 100. The adapted methodology was used to evaluate three transport policies in Bengaluru city relating to the integration of metro and feeder bus services. According to the analysis, the policy of increase in bus frequencies had the highest SII value, with an average increase of 4.97%, followed by policies of relocating bus stops and single ticketing systems, which had average increases of 3.49% and 4.58%, respectively
Proposal for Data Retrieval Methodology in Terms of Cross-border Commuter Mobility: A Perspective of Czech Employees
Get PDFLabor mobility between the Czech Republic and Germany represents a significant factor for the economic and social integration of cross-border regions. The manuscript focuses on the proposal of a methodology in the context of retrieving and analyzing data on labor mobility, with the aim of creating a strategy to support cross-border cooperation. Through a combination of specific quantitative and qualitative methods, the manuscript analyzes the key determinants of mobility, barriers, challenges and factors affecting the commuter decision-making. The findings show that the major obstacles to cross-border mobility include administrative burden, differences in working conditions, and institutional misalignment. The manuscript also discusses the possibility of optimizing the current data retrieval system using advanced technologies and analytical tools. The conclusions of the study provide suggestions for streamlining cross-border mobility and supporting labor market integration in the Czech-German border region
Aldehyde-modified Alkyd Resins Based on Waste Poly(ethylene terephthalate) Prepared by in situ Reaction Method for Sustainable Versatile Coating Systems
Get PDFThis study aims to develop novel aldehyde-alkyd systems for versatile coating applications from a four-component alkyd resin containing waste poly(ethylene terephthalate) (PET) using a sustainable approach. Post-consumer bottle flakes were depolymerized via a simultaneous hydrolysis-glycolysis reaction. PET-based and reference unmodified alkyd resins were synthesized with and without PET. In the PET-based alkyd formulation, the PET depolymerization product (DP) was used in place of the diol component of alkyd. To produce the modified alkyd resins, the aldehyde resin was incorporated into the reaction medium during the synthesis of the PET-based and reference alkyd resins. Thus, both unmodified and modified alkyds with and without PET were prepared for comparative analysis. The research focused on the effects of aldehyde resin usage and the presence of DP on the coating properties and thermal behavior of the modified alkyd films. The physical/chemical coating properties of both modified and unmodified resins were reasonably sufficient for applications. The hard films obtained from alkyds exhibited superior adhesion strength, excellent impact resistance, and high gloss. Moreover, they were unaffected by water and exhibited remarkable resistance to corrosive agents. Organic solvents did not adversely affect these films. All films demonstrated excellent performance in repeated environmental resistance tests simulating various climatic conditions. The coating and thermal properties of PET-based alkyd films were slightly superior to their reference counterparts due to the incorporation of DP, an oligomer mixture containing aromatic units. Furthermore, in situ aldehyde modification slightly increased alkali resistance and thermal stability and reduced gloss loss in PET-based alkyds
Innovative Green Extraction of Phenolic Compounds from Chicory (Cichorium Intybus) Using Natural Deep Eutectic Solvents
Get PDFIntroduction: Chicory (Cichorium intybus L.) exhibits antioxidant, antibacterial, antidiabetic, and anti-inflammatory properties, owing to its bioactive components, with flavonoids and phenolic acids being the most significant. Natural deep eutectic solvents (NADES) are increasingly used as an alternative to conventional solvents in the extraction of active compounds, thanks to their non-toxicity.Goal: To investigate the efficiency of flavonoid and phenolic acid ultrasound extraction from chicory herb and root using NADES and to compare the results with extracts obtained using conventional solvents–70% ethanol, methanol, and water.Material and methods: A total of sixteen samples were examined, eight samples of chicory herb and eight samples of chicory root. Extraction was performed using five different NADES, 70% ethanol, methanol, and water. NADES were prepared by mixing and heating. The content of phenolic acids and flavonoids was determined using high-performance liquid chromatography (HPLC).Results: Ten bioactive compounds were identified and quantified in the analyzed extracts: phenolic acids gallic acid, chlorogenic acid, para-hydroxybenzoic acid, caffeic acid, coumaric acid, ferulic acid, rosmarinic acid and epicatechin quercetin, and naringenin from flavonoids. In eight out of ten extracts obtained using NADES, the content of bioactive compounds was significantly higher compared to extracts obtained using conventional solvents–70% ethanol, methanol, and water.Conclusion: In this study, the efficiency of extracting phenolic acids and flavonoids from the root and herb of chicory using NADES was analysed and confirmed. The use of novel green solvents resulted in significantly higher yields of phenolic compounds compared to conventional solvents
Durability Indices of a Sealing Mortar Incorporating Blast Furnace Slag: Comparison with a Commercial Reference
Get PDFGround granulated blast furnace slag generated from steel manufacturing presents environmental challenges, but it can be valuable when utilized as a supplementary material in concrete, contributing to the development of sustainable materials. In this research, a new sealing mortar was prepared by substituting 10% of the cement with slag (M10). This material can provide performance comparable to M234, a M0 sealer used for sealing and wedging supports and machine bases. The mechanical properties and durability indices of both M10 and M234 were compared to the reference mortar MISO, which is a laboratory-made mortar free of slag. XRD analysis was conducted to determine the crystallinity of the starting cement, and granulometry revealed a median size distribution of 23 μm for the slag after grinding. Capillary absorption and water-accessible porosity were tested for all samples
Effects of Core Drilling Location on the Response of Eccentric Axially Loaded Columns under Cyclic Lateral Loads
Get PDFIn evaluating the performance of existing reinforced concrete buildings, compressive strength is determined by core samples taken from the structural elements. Regarding ease of application, the core area is selected as close to the column's bottom as possible. Although studies in the literature and relevant regulations state that coring should be done from the middle area of the columns, there is no evaluation of the behavior of the columns under different loading conditions. Besides, the location of the cored area can be ignored for symmetrically loaded columns; it will vary for eccentric axially loaded columns, which are frequently encountered in practice. Only axial load has been considered for the evaluations in studies investigating the effect of the cored area on the load-bearing element. However, this should also be evaluated under horizontal cyclic loadings that change the tensile and compressive zones of the load-bearing element. Therefore, this study aims to determine the most suitable coring area on the column by considering the literature, regulations and application situations in reinforced concrete columns subjected to eccentric axial loading and horizontal cyclic loading with the finite element method. In addition, the study aims to provide an academic basis for the importance of loading type (symmetric/eccentric) in selecting the core drilling area, which is often determined randomly in practice
A Probabilistic Assessment Method of Voltage Deviation Risk for Wind Power Access to Distribution Network Based on Total Probability Formula and Nataf Transformation
Get PDFDriven by the "dual-carbon" goals, the large-scale integration of wind power into distribution networks poses challenges to voltage stability due to its inherent volatility and uncertainty. To address it, this paper proposes a probabilistic assessment method based on the total probability formula that incorporates wind speed correlation to effectively evaluate voltage deviation. Firstly, the probability model of wind power is established according to the uncertainty of wind speed considering the correlation. Secondly, the wind power output is discretized and aggregated to ensure that the resulting random variables in the combined state approximately follow a normal distribution. Spatial correlations in wind speed are accounted for using the Nataf transformation. Furthermore, the probability of each aggregated wind power state determines its weight. These weights are then used to accumulate and integrate the probabilistic power flow (PPF) results. The total PPF calculation accounts for wind power uncertainty, following the Total Probability Formula (TPF) framework. Finally, considering the indexes with the probability and severity of voltage deviation, the comprehensive risk indicator for voltage exceeding limits is constructed. Based on the IEEE-33 bus test system, the proposed TPF method is compared with Monte Carlo Simulation (MCS) and the Two-Point Estimation Method (2PEM). The comparison demonstrates its superior computational accuracy and efficiency, establishing it as an effective tool for assessing the impact of wind power integration on distribution networks
Advanced Speaker Identification with CNNs and Maximum Likelihood Criterion
Get PDFSpeaker identification is a crucial topic in various fields, including linguistics, speech acoustic technology, and artificial intelligence. Despite the progress, speaker identification remains a challenge, particularly in acoustically noisy contexts or when the speakers are phonetically similar. Moreover, concerns regarding privacy and data protection frequently arise in speaker identification, particularly concerning the use of personal audio data. Signal processing and machine learning techniques have significantly advanced, improving the accuracy and resilience of voice recognition systems. New methods, including Convolutional Neural Networks (CNN), are advancing voice information extraction performance. This study aims to develop a Speaker Identification System based on deep learning techniques. These techniques have gained widespread recognition in the field of automatic acoustic signal processing. Many researchers have used convolutional neural networks, and the recognition phase is based on the cross-entropy criterion. This article proposes an advanced technique to combine convolutional neural networks with the maximum likelihood criterion. This proposed technique has yielded promising results when compared to traditional systems, such as Vector Quantization (VQ), and Gaussian Mixture Model (GMM). The suggested approach achieves an accuracy of 87.97% using all the data from the LibriSpeech corpus
Optimization of Steel Laser Cutting Processes Using the Roughness Parameter Sq and Response Surface Methodology (RSM)
Get PDFLaser cutting of steel is among the most advanced and competitive technologies in metal processing, widely employed in the automotive, aerospace, construction, and electronics industries, as well as in the production of precision components. Its advantages over traditional methods stem from its high precision, cutting speed, and ability to process complex geometries without requiring any subsequent finishing operations. This study presents research on the influence of fiber laser control parameters on the surface quality of S355J2C+N steel cuts. The primary objective is to identify which laser cutting parameters significantly affect the surface roughness of the cut. The response surface methodology (RSM) was employed for modeling. The Sq roughness parameter was selected as the primary metric to assess surface quality. The investigated process control parameters affecting surface roughness included feed rate, focal point position, and peak power. A 2-level split-plot experimental design was used for data analysis, with the focal point position designated as a hard-to-change factor due to the mechanical complexity of optical realignment. A mathematical model of the cutting process was generated. Based on analysis of variance (ANOVA), the model was found to fit the experimental data with an accuracy exceeding 98%. The results indicated that achieving low surface roughness (Sq) requires cutting with the lowest possible feed rate, lowest focal point position, and minimal peak power. The use of RSM facilitates the optimization of control parameter selection, contributing to improved surface quality and process efficiency