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Found 5157 publications
The Role of Domain Size and Boundary Conditions in Mathematical Modeling of Railway Tracks
Publication Name: Applied Mechanics
Publication Date: 2025-09-01
Volume: 6
Issue: 3
Page Range: Unknown
Description:
In developing a mathematical model of a railway track, the question of determining the dimensions of the modeling domain inevitably arises. If the modeling area is too small, boundary effects may significantly influence the results, reducing their accuracy. Conversely, excessively large areas can increase computational complexity without substantial improvements in accuracy. An optimal choice of dimensions enables the balancing of computational costs and accuracy. Solving this problem is non-trivial, as it depends on numerous factors, primarily the type of mathematical model and the problem being addressed. In most cases, preference is given to minimal domain sizes that ensure the approach’s adequacy. The aim of this study is to justify the dimensions of the modeling domain by addressing such tasks as load scaling, introducing additional boundary conditions, and making relevant assumptions. The main object of the study is the minimum adequate longitudinal length of the track for the spatial model. The research is based on the analytical application of modern approaches in the theory of elasticity. The results are analyzed using mathematical methods, such as modeling the railway track through the propagation of elastic waves and finite element modeling. These findings can be applied to a wide range of problems related to the mathematical modeling of the stress–strain state of railway tracks.
Open Access: Yes
Using Multivariate Statistical Analysis for Examining the Relationship between Food Waste Generation and Socio-economic Factors
Publication Name: Journal of Sustainable Development of Energy Water and Environment Systems
Publication Date: 2025-09-01
Volume: 13
Issue: 3
Page Range: 1-16
Description:
Food waste contributes to social inequalities and sustainability issues by worsening resource overuse and environmental harm. The United Nations Sustainable Development Goal 17 highlights the importance of reducing food waste to address hunger and promote a sustainable, economically viable global food system. This paper examines the geographic differences in food waste levels among European Union member nations and analyses the associations between food waste and diverse environmental, geographic, social and economic indicators, including Sustainable Development Goals and other sustainability metrics. Using dimensionality reduction methods, nontrivial multivariate connections between food waste and these parameters were identified, allowing for the characterisation of countries based on a few significant factors. Principal Component Analysis (PCA), applied to food waste data across European Union countries, uncovered three distinct groups: (1) those with elevated food waste in primary production, manufacturing and distribution stages; (2) those with lower waste in these domains yet elevated waste in restaurants and households; and (3) those with all of their food waste components smaller than or equal to the average. The multivariate linear correlation between the PCA factors and socio-economic parameters is nonsignificant, but a few (nonlinear) regularities could be identified: five of the six countries of the first group above are characterised by the population settled mainly on flatland and an above-average supply of meat or fish. Another pattern observed is that former Eastern Bloc countries belong to the third group. The research findings offer valuable insights that can inform the efforts of environmental experts, professionals and policymakers working in the circular economy and waste management domains. This knowledge can facilitate the development of more effective strategies aimed at mitigating food waste and promoting sustainability.
Open Access: Yes
Developing a Consistent and Transparent Corporate Sustainability Rating System with a Sector-Agnostic Approach
Publication Name: Journal of Sustainability Research
Publication Date: 2025-09-01
Volume: 7
Issue: 3
Page Range: Unknown
Description:
Background: Development of objective, quantitative sustainability reporting scores for international companies has to be based on legal, regulatory, and public policy standards as well as focused exclusively on environmental, social, and governance (ESG) issues. The key performance indicators (KPIs) developed here differ from traditional agencies’ rating schemes in that they are equally applicable across industrial sectors. They measure performance in terms of several environmental Global Reporting Initiative (GRI) indicators. The KPIs quantify performance by systematically linking corporate revenues with sustainability metrics, thereby yielding readily comparable, numerical scores. Methods: This report illustrates their utility with data on carbon dioxide (CO2 ) emissions from leading companies within the S&P Global ESG ranking for 2023. Results: The findings reveal significant gaps in managing Scope 3 emissions, which dominate the value chain and present the greatest challenge for corporate sustainability. These disparities highlight the need for improved data transparency and harmonized reporting standards to ensure consistent and actionable sustainability assessments. Conclusions: By bridging these gaps, the KPIs enable more equitable comparisons across industries and encourage better alignment of corporate strategies with global climate objectives. The additional transparency and insights in turn afford investors, managers, policy makers, and other stakeholders’ better information for their decision making.
Open Access: Yes
DOI: 10.20900/jsr20250054
Robustness of a flux-intensifying permanent magnet-assisted synchronous reluctance machine focusing on shifted surface-inset ferrite magnets
Publication Name: Computers and Structures
Publication Date: 2025-09-01
Volume: 316
Issue: Unknown
Page Range: Unknown
Description:
Flux-intensifying permanent magnet-assisted synchronous reluctance machines use relatively small amounts of non-rare earth permanent magnets, making them viable alternatives for remanufacturing older machines, aligning with EU directives and circular economy principles. The asymmetric rotor topology is particularly suited for micromobility applications, which benefit from shifting inset magnets, as reverse motoring is rarely required. However, this design could be more sensitive to manufacturing and positioning errors of the magnets. To investigate the effects of the uncertainties of the shifted surface inset magnets, first, an optimal topology is selected based on average torque, torque ripple, and cogging torque using the NSGA-II optimisation method. The effects of the magnet shifting and its robustness are analysed using the Taguchi and ANOVA methods, validated by Full Factorial calculations. Results indicate a 31.25 % reduction in permanent magnet volume without compromising torque output with magnet shifting. The machine's average and cogging torque remain within a 5 % robustness threshold for a ±0.06 mm discrete manufacturing tolerance. Torque ripple may exceed this limit up to 14.77 %. However, the likelihood of exceeding the threshold is only 12.10 %. The reduced magnet volume and maintained performance make this topology a promising option for remanufactured machines in micromobility applications, supporting circular economy goals.
Open Access: Yes
Influence of Cyclic Loading on the Removal Torque of Unique Subperiosteal Implant Screws
Publication Name: Journal of Functional Biomaterials
Publication Date: 2025-09-01
Volume: 16
Issue: 9
Page Range: Unknown
Description:
During the investigation, the effect of screw tightening torque on the potential loosening of screws under load was examined in the case of custom-made subperiosteal implants. The study focused on the connection screws between the implant components, testing the commonly applied tightening torques of 15 Ncm and 30 Ncm. Mastication was simulated using a custom-designed, PLC-controlled testing device, which allowed for the reproduction of variable numbers, forces, and speeds of bite cycles. With this device, six different scenarios were tested, including 500, 2000, and 10,000 bite cycles, under both constant and variable bite forces. A caliper was used to record potential length changes of the screws, force sensors measured the bite forces, and calibrated torque screwdrivers were used to verify the loosening torques. Based on the analysis of the measured data, it was concluded that for the M1.8 screws tested, a tightening torque of 15 Ncm does not provide sufficient resistance against loosening, whereas 30 Ncm offers adequate stability.
Open Access: Yes
DOI: 10.3390/jfb16090306
Exploring the impact of compressibility on reconstructed porous materials: A numerical study
Publication Name: Journal of Engineering Research Kuwait
Publication Date: 2025-09-01
Volume: 13
Issue: 3
Page Range: 1987-2003
Description:
This study underscores fluid density's significance in CFD simulations for porous materials, addressing its impact on accuracy and computational efficiency. The paper proposes a tailored form of Navier-Stokes equations that accounts for fluid density's influence on CFD analyses of porous materials in industrial contexts, including cases where the solid phase is deformable. Numerical analyses demonstrate fluid density's significance (ρ≠constant) and explore the importance of the energy equation in governing equations. The energy equation is essential in setting up the governing equations, as it calculates thermal characteristic length based on cell temperatures. By examining various porous material samples, the study suggests a streamlined approach: employing a single coupled CFD-FEM simulation to directly determine each geometrical parameter. Additionally, the study investigates the capability to accurately simulate turbulent fluid motion at the pore scale and analyze the flow field characterization within porous media. Computational cost analyses underscore the advantages of coupled simulations, establishing their profitability over separate parameter-specific simulations.
Open Access: Yes
Optimisation of island integrated energy system based on marine renewable energy
Publication Name: Fundamental Research
Publication Date: 2025-09-01
Volume: 5
Issue: 5
Page Range: 2161-2179
Description:
Integrating marine renewable energy (MRE) with conventional energy sources and logically constructing island energy systems is crucial for alleviating island energy supply challenges and helping coastal energy systems achieve a sustainable, low-carbon transition. In this study, the status of marine energy utilisation technologies is reviewed, with a focus on advancements in energy conversion equipment, grid integration, and energy storage. The economic feasibility and environmental sustainability of marine energy systems are comparatively analysed to enhance the development and utilisation of marine energy technology while reducing the economic cost of power generation. Suitable equipment is highlighted for islands, with efficient energy generation strategies proposed to achieve cleaner, localised, and cost-effective island integrated energy system (IIES) design. Island energy facilities vary, and integrated development is crucial for building new energy systems. Based on the types and resources of island energy, IIESs are constructed for hierarchical energy utilisation and multi-energy coupling, coordinating resources to achieve source–grid–load–storage integration. The optimisation of IIESs is reviewed, with a focus on modelling methods, intelligent algorithm development, and system simulation. This study differs from previous research as it considers the integration of marine energy into existing systems to achieve comprehensive integration of multiple energy sources. Additionally, optimisation and solution methods for IIES models are summarised. To integrate complex, multivariable energy systems and create stable and predictable outputs, marine energy and load forecasting methods are explored. Overall, this study supports the advancement of marine energy utilisation, focusing on its progressive integration into island energy systems as the efficiency of marine energy improves. This work aims to inspire the development of new functions and modules based on existing system optimisation and forecasting techniques.
Open Access: Yes
Változások az orvosok, védőnők és egészségügyi szakemberek gyermekvédelmi munkájában, ajánlások a további munkához: Tanulmány a Védőnői Szolgálat 110 éves évfordulója alkalmából
Publication Name: Orvosi Hetilap
Publication Date: 2025-08-31
Volume: 166
Issue: 35
Page Range: 1391-1400
Description:
Introduction: From 13 June 1915, when the National Stefania Association was founded, for almost a century, the health visitors, alongside the doctors, were the health-social-child protection carers of children and families with children, the coordinators of this work. Objective: (1) To review the changes in the last decades that have changed the work of doctors, health visitors and health professionals in child protection; (2) to describe their place and responsibilities in the child protection system; (3) to make suggestions based on our professional experience on how they can work more effectively to better represent the interests of children in need. Method: We studied the legislation, professional regulations and literature related to the topic, and we also carried out systematic and analytical work based on our own professional experience. Results: Act III of 1993 on social welfare, Act XXXI of 1997 on child protection, and the creation of the family and child welfare services and centres in 2016, brought radical changes. Health professionals play a key role in the child protection signalling system and work together with other child protection actors. Our own health-child protection DDTT (Detection–Diagnosis–Treatment–Therapy) model and checklist, which have proved successful in our own work, can be used to help health professionals in their health-child protection work. Discussion: The place and responsibilities of doctors, health visitors and health professionals in the child protection system have become clearer. The role of all health professionals is very important in this work. Conclusion: More attention should be focused on cases within their own competence, on primary prevention in the field of health and child protection. Teamwork, traditionally important in the health sector, is also important in the health and child protection field. Also to follow the changes, participation in training courses is recommended. For more effective work, we recommend the use of the DDTT model and checklist, which have been well proven in our own work in health and child protection. Orv Hetil. 2025; 166(35): 1391–1400.
Open Access: Yes
Engineering Elegance at Altitude
Publication Name: Epites Epiteszettudomany
Publication Date: 2025-08-21
Volume: 53
Issue: 3-4
Page Range: 323-346
Description:
Water towers are a characteristic vertical visual element of today’s townscapes and rural landscapes. We encounter them in urban residential areas, industrial zones, but they are also decisive in the silhouette of villages. Their task is most often to ensure the supply of drinking water to the population, but we often encounter water towers belonging to industrial, railway or agricultural plants.In terms of their appearance, most water towers are simple engineering creations, but in some cases, the creators also placed emphasis on the aesthetic design of the structure.Historical water towers have survived from the 19thcentury, they were built using traditional construction techniques, usually with historicizing architecture. A significant part of the memorial material comes from the period between the two world wars, which is the time of the construction of early reinforced concrete structures; the appearance of the buildings is also determined by this structure. In the second half of the 20thcentury, the material of the towers continued to be reinforced concrete, but dynamic, architecturally sophisticated formal solutions were more common.Our study analyses the historical development of water towers, including their structural development, changes in form, and role in the settlement or landscape.
Open Access: Yes
