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Found 6374 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
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
Mind the Net: Parental Awareness and State Responsibilities in the Age of Grooming
Publication Name: Social Sciences
Publication Date: 2025-09-01
Volume: 14
Issue: 9
Page Range: Unknown
Description:
In the digital environment, grooming—classified as a communication-based risk—has shown a steadily increasing frequency in recent years. In Hungary, increasing attention has been directed to the protection of children’s rights in the digital space in alignment with ensuring their online safety, with both parents and the state playing crucial roles in ensuring a safe digital presence. Within this context, the state bears a particular responsibility to educate not only children but also parents. This study explores how public policies and institutional programs in Hungary address the prevention of grooming and the reactive management of this harm through parental awareness. It examines existing measures aimed at expanding knowledge related to prevention and response, based on a qualitative analysis of the normative foundations of the state’s educational obligations and the relevant academic literature. The study relies on questionnaire data collected from parents of children aged 7 to 18 to examine the effectiveness of state measures and parents’ perceptions of them. The findings of the empirical research may support the development of state-led parental education programs and identify current gaps. As such, it can play a guiding role in shaping the direction of a future, large-scale investigation.
Open Access: Yes
Can multifarious types of green bonds be accused of greenwashing with a durative analysis? Insights from a permanent causality vs. temporary causality phenomenon
Publication Name: Environment Development and Sustainability
Publication Date: 2025-09-01
Volume: 27
Issue: 9
Page Range: 21425-21449
Description:
Green bonds are useful monetary tools that can finance sustainable endeavors to bolster an eco-friendly economy. This research inspects the frequency-domain causal relationship between diverse green bond types and the green economy from June 30, 2014 to August 3, 2023. The goal is to understand both permanent and temporary causal phenomena between them. The findings reveal that only pioneering green bonds display a robust bidirectional causal link with an eco-efficient economy. Meanwhile, other green bond types, like conventional, municipal, and currency-dominated green bonds, may be susceptible to greenwashing due to the absence of a thorough permanent causal tie with an ecologically sustainable economy. Additionally, enhancing pioneering green bonds by integrating ESG (Environmental, Social, and Governance) stocks can transform the cause-and-effect dynamic between specific green bonds and the green economy. It shifts from a bilateral cause to a unilateral one stemming from the environmentally friendly economy and extending to distinguished green bonds. This phenomenon persists whether the 5% annual fee for sustaining and managing the index combining green bonds and ESG equities is considered or not. Interestingly, an environmentally conscious economy, in both persistent and transient associations, consistently affects ecological bonds with diverse traits. This highlights the importance of the overall state of an environmentally responsible economy in enhancing green bonds. These discoveries provide novel perspectives for green market regulators and policymakers to design improved standards for green assets.
Open Access: Yes
Pollinator benefits of small-scale landscapes depend also on semi-natural habitat
Publication Name: Journal of Applied Ecology
Publication Date: 2025-09-01
Volume: 62
Issue: 9
Page Range: 2249-2260
Description:
Farmland pollinators are influenced by landscape structure, including mean field size, floral resources, the amount of semi-natural habitats and crop type, but their relative importance and interactions for bumblebee colony performance are not well known. In our study, we focused on the concurrent role of crop type (oilseed rape vs. cereal), proximity to semi-natural habitats (close vs. far) and landscapes with small (average 2 ha) and large fields (average 17 ha) on experimentally exposed bumblebee colony fitness parameters; we also carried out a botanical survey and analysed pollen collected by the bumblebees. We conducted a homing experiment, with workers translocated 0.1–1 km from the colony, and measured the homing speed. We found a significantly higher colony traffic rate next to mass-flowering oilseed rape fields and close to semi-natural habitats. According to our structural equation model, higher traffic rates boosted colony growth rates, which in turn supported higher queen brood cell numbers. In the homing experiment, the relocated bumblebees returned to their home colony faster when it was located close to semi-natural habitats and when the flowering plant species richness was high. The homing speed was lower when semi-natural habitats were distant and flowering plant species richness was high, possibly due to fewer visual cues. Semi-natural habitats were more important for pollinators in large-scale than in small-scale agriculture. In small-scale landscapes, bumblebees returned more quickly when flowering plant species richness was low, presumably because the small-scale landscape structure (higher edge density) allowed for easier navigation by landscape visual cues. The abundance of flowering plants did not affect homing speed, presumably underlining the predominant role of orientation in small-field landscapes. Synthesis and applications: Mass-flowering crops and nearby semi-natural habitats enhance colony growth and queen production, emphasising the important role of abundant and diversified flower resources as well as neighbouring semi-natural habitats. Further, landscapes shaped by small-scale farming are crucial for sustaining and enhancing pollinator populations. Our results underscore the need to restore and maintain semi-natural habitats and to enhance floral resources. These efforts are especially effective in small-scale agricultural landscapes, which appear to improve bumblebee orientation and support biodiversity-friendly farming.
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
József Lőrincz, the Star Architect of the Designing and Planning Institute of Győr
Publication Name: Epites Epiteszettudomany
Publication Date: 2025-08-21
Volume: 53
Issue: 3-4
Page Range: 347-388
Description:
Although between 1948 and 1990, architectural practice was largely confined to state- and council-run design enterprises, the system was not so rigid as to preclude the emergence of architectural roles familiar even in contemporary practice. At the Designing and Planning Institute of Győr, for instance, József Lőrincz (1930–1990) embodied the figure of the star designer—an architect who operated within the institutional framework of the enterprise but pushed its boundaries to the utmost, thereby gaining opportunities that were accessible to only a few of his contemporaries.This study examines Lőrincz’s oeuvre through both his realized works and a selection of unbuilt projects. My objective is to reconstruct the Győr phase of his career to illustrate a possible strategy for achieving professional autonomy and self-actualization within the institutional framework of a socialist state regional design enterprise. The study also approaches the topic from the perspective of professional history by exploring certain institutional-historical aspects.Through Lőrincz’s body of work, actions, and decisions, multiple facets of state-controlled architectural design are revealed, delineating the social, political, economic, and professional networks that shaped his career. Furthermore, the analysis highlights how his involvement in local political decision-making and his personal relationships with local investors influenced not only his own trajectory but also the structure of the design institute and even the architectural history of the region during that era.
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
Enhancing 3D Precision: Point Cloud Upsampling Methods — A Review
Publication Name: Periodica Polytechnica Civil Engineering
Publication Date: 2025-08-19
Volume: 69
Issue: 3
Page Range: 689-702
Description:
Enhancing the resolution of point clouds is crucial in achieving detailed and precise 3D representations for various applications. Factors such as sensor calibration, scanning range, and environmental capability play a pivotal role in determining the overall quality of the captured point cloud data. Moreover, issues related to noise, occlusions, and sensor limitations can further impact the accuracy of the modelling outcome, underscoring the importance of optimizing point cloud resolution. Thus, researchers started to build new architectures with the aim of produce more dense and complete representation with higher resolution. Different methods have been created to achieve successful upsampling, such as interpolation techniques, deep learning strategies, and optimization algorithms. In this paper, we take a closer look at this exceptionally fast-developing field of science. According to this aim, the reader will better understand point cloud upsampling technology.
Open Access: Yes
DOI: 10.3311/PPci.38617
