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Found 6289 publications

Analytical Overview of Accident Emergencies Arising from the Structure and Characteristics of Various Alternative Fuel Vehicles †

István Lakatos Lea Pődör

Publication Name: Engineering Proceedings

Publication Date: 2025-01-01

Volume: 113

Issue: 1

Page Range: Unknown

Description:

The spread of alternative fuel vehicles (AFVs) poses new technological and legal challenges. While these vehicles contribute to sustainable transport, their specific operational characteristics require specific regulation and infrastructure. The study analyses the risks associated with AFVs, in particular with regard to occupational safety and operation, and the extent to which the current legal framework in Hungary is able to address these challenges. It also examines the integration of AFVs into the existing transport and service network and makes recommendations for improving regulation, training and infrastructure. The study aims to contribute to enhancing road safety and legal clarity by showing that the safe integration of AFVs requires the modernisation of regulation and the adaptation of technical protocols.

Open Access: Yes

DOI: 10.3390/engproc2025113070

Towards the efficient simulation of telecommunication systems in heterogeneous distributed execution environments

László Muka István Derka Gábor Lencse

Publication Name: 2013 36th International Conference on Telecommunications and Signal Processing Tsp 2013

Publication Date: 2013-10-21

Volume: Unknown

Issue: Unknown

Page Range: 304-310

Description:

An introduction is given to the topics of the parallel and distributed simulation and of the modeling of telecommunications systems. Our practical modeling concept for simulation in heterogeneous execution environment is presented. Its logical topology is a star shaped network of homogeneous clusters. The load balancing and the coupling factor criteria are set up for building models of telecommunications systems so that the simulation may produce good speed-up in a heterogeneous distributed execution environment. A case study is given with the open source OMNeT++ discrete-event simulation system and its parallel CQN (closed queueing network) sample model executed by 64 CPU cores of four different types. Our criteria are heavily supported by the results of our experiments. © 2013 IEEE.

Open Access: Yes

DOI: 10.1109/TSP.2013.6613941

Effect of Chemical Composition of Clay on Physical-Mechanical Properties of Clay Paving Blocks

Saulius Baskutis Valentinas Navickas László Tamándl Rolandas Avizovas

Publication Name: Buildings

Publication Date: 2022-07-01

Volume: 12

Issue: 7

Page Range: Unknown

Description:

Clay paving blocks made of natural, environmentally friendly materials have their own originality and colorful authenticity, but due to the complex technological production process, they are also relatively expensive products; therefore, their environmental resistance properties are strictly defined and controlled by the standards. The physical and mechanical properties of clay paving blocks are the key factors aiming to ensure the longevity of products and their long-term success in the market. Therefore, ensuring high physical and mechanical properties of clay paving blocks have become a most crucial challenge for the manufactures. This article considers the parameters of the technological production process of clay paving blocks manufacturing and evaluates the influence of the chemical composition of three different types of clay on the physical and mechanical properties of the paving blocks. Water absorption, linear shrinkage, freeze/thaw, acid resistance, and transverse breaking load of clay paving blocks are investigated. This study reveals the importance of raw material selection in the production process of clay paving blocks and provides the concept of main quality factors of clay.

Open Access: Yes

DOI: 10.3390/buildings12070943

Efficient Layer-by-Layer Processed Small-Molecule Donor/Polymer Acceptor Solar Cells: Morphology-Dependent Charge-Transfer Mechanisms

Gusztáv Fekete Hai Qiao Wang Shu Xu István Bíró Xingyu Liu Beining Wang Zhongle Chen Yuxuan Wang Chenghuan Chen

Publication Name: ACS Photonics

Publication Date: 2026-01-21

Volume: 13

Issue: 2

Page Range: 424-432

Description:

Small-molecule donor:polymer acceptor (SMD:PA) organic solar cells have garnered attention due to their excellent active layer stability, yet their efficiency remains significantly lower than other OSC types. This study addresses the challenge of morphology control in SMD:PA systems via a layer-by-layer (LBL) process to optimize the donor–acceptor interpenetrating network. Using small-molecule donor B1 and polymer acceptor PY-IT with chloroform as a universal solvent, we systematically investigated the impact of LBL processing on the active layer morphology and device performance. The inverted LBL device (ITO/ZnO/PY-IT/B1/MoO3/Ag) achieved a power conversion efficiency of 8.6%, significantly outperforming the bulk heterojunction devices (inverted 2.91% and normal 6.11%) and previously reported LBL SMD:PA cells (1.12%). Static and femtosecond transient absorption spectra, time-resolved photoluminescence, and grazing incidence X-ray diffraction analyses revealed that the LBL and nonorthogonal solvent strategy facilitated effective B1 infiltration into the PY-IT layer, forming an optimized active layer with refined phase separation and improved donor/acceptor interfaces, thus resulting in enhanced exciton dissociation and charge transport while reducing recombination losses. This work validates the feasibility of LBL processing for high-efficiency SMD:PA OSCs, offering a novel strategy to overcome the efficiency limitations of this class of OSCs.

Open Access: Yes

DOI: 10.1021/acsphotonics.5c02041

Optimization of Bolted Steel T-Stub Connection Based on Nonlinear Finite Element Analysis Using Genetic Algorithm

Majid Movahedi Rad Péter Grubits Tamás Balogh

Publication Name: Infrastructures

Publication Date: 2025-01-01

Volume: 10

Issue: 1

Page Range: Unknown

Description:

The equivalent T-stub method is frequently employed in infrastructure projects, including bridge engineering, to simplify bolted connection analysis. However, steel connections remain inherently complex due to nonlinear behavior, cost considerations, and code compliance, framing the design process as a discrete structural optimization problem. This research addresses these challenges by presenting a comprehensive calculation framework that combines the finite element method (FEM) and genetic algorithm (GA) to accurately evaluate the structural performance of bolted T-stub configurations. The proposed approach accounts for nonlinear behavior, thereby reflecting realistic structural responses. To enhance the simulation efficiency and reduce the computational time without significantly compromising accuracy, the study introduces a simplified modeling methodology. The effectiveness of the approach is demonstrated through the development and experimental validation of a selected T-stub connection. Furthermore, a parameter sensitivity analysis is conducted to showcase the range of possible outcomes, emphasizing the potential for optimization. Finally, the proposed connections were optimized using GA, highlighting the benefits of structural optimization in achieving efficient and precise designs for steel connections.

Open Access: Yes

DOI: 10.3390/infrastructures10010008

Description of an arboreal oribatid mite species of the genus Ovobates (Acari, Oribatida, Oribatulidae), based on adult and nymphs from Vietnam

Jenő Kontschán Sergey G. Ermilov

Publication Name: Zootaxa

Publication Date: 2026-01-14

Volume: 5748

Issue: 3

Page Range: 112-124

Description:

The genus Ovobates (Oribatida, Oribatulidae) comprises two species distributed in the Oriental region. A new species— Ovobates ochrocarpicus sp. nov.—is described, based on adult and nymphal instars, collected from branches of the ochrocarp tree in southern Vietnam. The adult of the new species is characterized by the presence of the five pairs of notogastral porose areas and the epimeral formula 3-1-3-3. The nymphs of the new species are characterized by presence of clavate bothridial seta; setiform interlamellar seta; short, setiform, thin gastronotic setae c1, c2, da, la; medium-sized to long, setiform, gastronotic setae dm c3, lm, p2, and p3; medium-sized, bacilliform gastronotic setae dp, h1, and h3; long, subflagellate, gastronotic setae lp, h2, and p1; epimeral formula 3-1-2-2 in tritonymph; and seven setae on the leg tarsus IV in protonymph. The generic diagnosis and a morphological comparison of adults and juvenile instars of the known species of Ovobates are presented.

Open Access: Yes

DOI: 10.11646/zootaxa.5748.3.1

Modeling Kinematic and Dynamic Structures with Hypergraph-Based Formalism

Csaba Hajdu Norbert Hegyi

Publication Name: Applied Mechanics

Publication Date: 2025-12-01

Volume: 6

Issue: 4

Page Range: Unknown

Description:

This paper introduces a hypergraph-based formalism for modeling kinematic and dynamic structures in robotics, addressing limitations of the existing formats such as Unified Robot Description Format (URDF), MuJoCo-XML, and Simulation Description Format (SDF). Our method represents mechanical constraints and connections as hyperedges, enabling the native description of multi-joint closures, tendon-driven actuation, and multi-physics coupling. We present a tensor-based representation derived via star-expansion, implemented in the Hypergraph Model Cognition Framework (HyMeKo) language. Comparative experiments show a substantial reduction in model verbosity compared to URDF while retaining expressiveness for large-language model integration. The approach is demonstrated on simple robotic arms and a quarter vehicle model, with derived state-space equations. This work suggests that hypergraph-based models can provide a modular, compact, and semantically rich alternative for the next-generation simulation and design workflows. The introduced formalism reaches 50% reduction compared to URDF descriptions and 20% reduction compared to MuJoCo-XML descriptions.

Open Access: Yes

DOI: 10.3390/applmech6040074

Successive Mechanical Recycling of Poly(lactic Acid) by Injection Molding: Evolution of Molecular, Thermal, and Mechanical Properties

László Lendvai Sándor K. Jakab Virág Luca Bódi Petar Sabev Varbanov Martin Danko

Publication Name: Macromolecular Materials and Engineering

Publication Date: 2026-03-01

Volume: 311

Issue: 3

Page Range: Unknown

Description:

This study evaluated the changes in the molecular structure, as well as the thermal and mechanical properties of poly-lactic-acid (PLA), during successive closed-loop mechanical recycling through injection molding. Gel permeation chromatographic (GPC) analyses revealed a gradual decrease in molar mass (MM); after ten recycling steps, the MM of PLA was reduced to one-third of its initial value. According to differential scanning calorimetric (DSC) measurements, both the glass transition temperature and the cold crystallization temperature of PLA decreased, while the crystallization was facilitated by the successive recycling steps. This was ascribed to the improved chain mobility resulting from the reduced MM. Quasi-static mechanical properties were evaluated using tensile tests, while impact toughness was assessed through Charpy tests. The tensile strength of PLA was not significantly affected by recycling until the fifth recycling step, where it suffered a slight (∼5%) reduction. Meanwhile, Young's modulus, elongation at yield, and impact strength remained approximately the same as the freshly injected sample at that point. However, after ten recycling steps, all analyzed properties declined significantly: Young's modulus by 11%, tensile strength by 68%, elongation at yield by 63%, and impact strength by 30%.

Open Access: Yes

DOI: 10.1002/mame.202500349

UNVEILING SCHOLARLY NARRATIVES ON HUMAN TECHNOLOGY: A STRUCTURAL TOPIC MODELING APPROACH

Wojciech Jarecki Magdalena Olczyk Monika Imreh-Toth Przemysław Olczyk

Publication Name: Human Technology

Publication Date: 2025-01-01

Volume: 21

Issue: 3

Page Range: 511-529

Description:

This study systematically maps the thematic evolution of human–technology research from 2020 to 2025 using Structural Topic Modelling (STM) applied to over 2,000 abstracts from the Web of Science Core Collection. The analysis identifies six dominant themes: Industry, AI and Sustainability; Education and Human-Centred Design; Public Health, Community and Equity; Robotics, HRI and Ergonomics; Philosophy and Ethics of Technology; and Clinical mHealth and Usability. The results reveal a structural realignment from pandemic-driven experimentation to institutionalised, interdisciplinary research embedded in industrial, clinical, and community systems. Thematic inequality declined while diversity stabilised, indicating a mature and balanced research ecosystem. Methodologically, the study introduces a reproducible STM-based workflow integrating Gini and Shannon indices. Empirically, it provides a data-driven map of cross-disciplinary convergence. Conceptually, it demonstrates that human–technology inquiry increasingly operationalises ethics and sustainability through design, governance, and applied practice.

Open Access: Yes

DOI: 10.14254/1795-6889.2025.21-3.2