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Found 6374 publications

Numerical investigation of composite metal foams using substructure techniques

Imre Norbert Orbulov Balázs Pere Márió Kovács

Publication Name: Composite Structures

Publication Date: 2025-01-01

Volume: 353

Issue: Unknown

Page Range: Unknown

Description:

An accurate description of the mechanical behaviour of inhomogeneous, anisotropic composite materials, such as metal matrix syntactic foams (MMSFs), is a challenging task. This paper is based on the so-called substructure technique, which has never been used for the mechanical modelling of metal foams or MMSFs. Using this method, a finite element model with low computational requirements but still modelling inhomogeneous properties can be constructed that reproduces the results of laboratory measurements with high accuracy. In all cases, the tests presented in this paper are limited to the linearly elastic phase. As the most common investigation of MMSFs is the compression test, this study considers only this loading case. A more detailed discussion of the stress analysis of MMSFs is given at the end of this work. A potential cause of 45° crack planes during compression tests and the evolution of stresses as a function of space-filling are also investigated.

Open Access: Yes

DOI: 10.1016/j.compstruct.2024.118731

A Novel Coenergy Based Torque Calculation Method for the Reluctance Motor Drives of Electric Vehicles

István Szászi Tibor Vajsz Csongor Horváth Richárd Csaba Kovács Vilmos Paiss István Szászi

Publication Name: Proceedings 2025 IEEE 7th Global Power Energy and Communication Conference Gpecom 2025

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: 210-215

Description:

Nowadays, the field of electric mobility is experiencing a rapid evolution. The need for more competitive electric vehicles is affecting the field of electric motor drive systems as well, placing the alternative types of electric motors into the center of research attention. The reluctance motors are one of these alternative motor types, but their highly nonlinear characteristics place a significant burden to their application. The stator inductances are varying in the function of the stator currents, and also in the function of the rotor position due to the magnetically asymmetric rotor structure. This means that the traditional calculation methods for the electromagnetic torque of the machine yield in inaccurate results. Therefore, this paper presents a novel, generalized coenergy-based torque calculation method, which eliminates a significant constraint of the traditional magnetic energy- and coenergy-based torque calculation methods, and considers the highly nonlinear behavior of the machine as well.

Open Access: Yes

DOI: 10.1109/GPECOM65896.2025.11061976

A Novel Approach to the Operationalization of Corporate Local Embeddedness: Cultural Perspectives on Narrativesas Indicators

Zsuzsanna Pálffy

Publication Name: European Journal of Interdisciplinary Studies

Publication Date: 2025-01-01

Volume: 17

Issue: 1

Page Range: 101-123

Description:

Corporate embeddedness, the extent to which companies anchor themselves in a local context through political, economic, academic, social, andenvironmental connections, remains a key area of research in social and regional sciences. Due to the limited availability of secondary data on corporate relationships, measurement methods often rely on qualitative data. Corporate communication, especially CEO letters in annual reports, is a frequently neglected secondary data source that has grown in significance in meeting stakeholder expectations and providing insights into corporate strategies and operations. Despite the growing scholarly interest in CEO letters, little is known about embeddedness narratives and the cultural factors that influence them. Through an analysis of the cultural variations in embeddedness narratives found in CEO letters from the fashion and cosmetics industries, this study suggests a novel approach to operationalising corporate localembeddedness. The focus on these sectors is justified by the significant variations in embeddedness orientations across industries and the accessibility of relevant data. The study finds that CEO letters can serve as a complementary data source for assessing corporate embeddedness, as they reveal both local and global orientations. Using software-based content analysis, key themes and keywords were identified along the Quintuple Helix model, providing a structured approach to analysing embeddedness. The results highlight cultural influences, with reactive cultures emphasising social sustainability, while academic engagement challenges existing assumptions. In addition to reflecting corporate strategies, CEO letters offer insights into sectoral characteristics. However, more qualitative research is still required to fully comprehend a company’s level of embedding.

Open Access: Yes

DOI: 10.24818/ejis.2025.07

Body Conformation Scoring of Cattle, using Machine Learning

István Szabó Bence Tarr János Tőzsér

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2025-01-01

Volume: 22

Issue: 3

Page Range: 27-38

Description:

Precision agriculture brings new artificial intelligence techniques closer to everyday farming. Agriculture historical data is easily available, so using this data to teach a machine-learning model, offers various opportunities to enhance farming efficiency. In our study, we develop a machine learning model to estimate some linear traits of Limousin sires (sore for muscularity, length of the rump, muscularity of breast and muscularity of the width of rump), based on a phenotypic score, using artificial intelligence, in Hungary. Phenotypic scores are usually given by the experts in field. Before scoring, many measurements are made on the animals, which takes time and places a high stress on the cattle. A hands-on prediction application can make the whole process faster, and more comparable, regardless of the expert who created the scoring. We found that after collecting sufficient data from previous observations it is possible to train specifically selected artificial intelligence (AI) algorithms to predict linear traits in Limousin breeding bulls. Machine learning (ML) was used to predict the score values for muscularity, length of the rump, muscularity of the breast and muscularity of the width of the rump for this study. We found no similar experiments for the usage of AI algorithms to predict these variables. The coefficient of determination (R2) of the algorithm, in this study, provided the following range values: (R2=0.77 to 0.86).

Open Access: Yes

DOI: 10.12700/APH.22.3.2025.3.2

Minimum Curvature Trajectory Planning for Autonomous Vehicles in a Hierarchical Framework

Szilárd Aradi Árpád Fehér Dániel Losonczi László Palkovics

Publication Name: 11th 2025 International Conference on Control Decision and Information Technologies Codit 2025

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1331-1336

Description:

This paper presents an approach for global trajectory planning using quadratic optimization and dynamic programming. In the global route planning phase, the goal is to find a route with minimal curvature for any road geometry, while a speed profile is determined by dynamic programming based on the vehicle's dynamic constraints. The method has a low computational cost and is well-suited for integration within a hierarchical system architecture, where the trajectory can be further refined with local route planning to enable the vehicle to adapt to changing environmental conditions. The developed method ensures vehicle stability while achieving the highest possible speed. The approach is implemented in the Frenet coordinate system within a self-developed simulation environment that allows for a comprehensive evaluation of vehicle dynamics, trajectory feasibility, and performance metrics. The results show that the proposed method can generate smooth and dynamically feasible trajectories while balancing curvature minimization, safety, and computational efficiency, making it well-suited for real-world applications.

Open Access: Yes

DOI: 10.1109/CoDIT66093.2025.11321486

Impact of Digital Business Communication on Expanding Sustainability in B2B Supply Chains

Edit Süle Matthew Boota

Publication Name: Chemical Engineering Transactions

Publication Date: 2025-01-01

Volume: 121

Issue: Unknown

Page Range: 133-138

Description:

In this digital era, the adoption of digital technologies is transforming business processes and helping organizations to achieve goals both domestically and globally. The role of digital businesses' communication in the B2B supply chain has become increasingly extensive. Digital technologies are helping companies to streamline their transactions more safely, enhance collaboration, and build trust among partners. Digital technology tools help businesses to improve sustainability by enhancing visibility, enabling real-time information, and facilitating product tracking throughout the entire supply chain. Earlier research explored digital tools in supply chains, but there is limited research on how these tools support business communication in supply chain sustainability. The study addresses this gap by conducting a systematic literature review of 102 journal papers from the Scopus and Web of Science databases. Out of the 732 articles initially screened, 102 were chosen, which is a selection rate of 13.9 %. The data show that the number of publications rose by more than 60 % between 2022 and 2024. This shows that audience interest is being increased in using digitalization to make supply chains sustainable. This paper outlines how digital technologies such as blockchain, ERP, cloud, and RFID help industries reach digital sustainability. The study has also presented real-world case studies of Walmart and Unilever that explain the importance of digitalization in the supply chain. This review suggests a noticeable increase in research on implementing digital tools in sustainable supply chain processes.

Open Access: Yes

DOI: 10.3303/CET25121023

Investigation of the Modified Ballast Breakage Index for a Laboratory Test Series using the Proctor Compactor Machine

Szabolcs Fischer Erika Juhasz

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2025-01-01

Volume: 22

Issue: 4

Page Range: 137-157

Description:

The rock physics properties of the crushed railway ballast include resistance against breakage and wear. The qualification of such materials and their compliance with requirements is mainly considered by two standard tests: The Los Angeles abrasion and Micro-Deval wear resistance tests. These tests are indispensable for the legally mandatory qualification of aggregates, but several measurement methods have been developed that better simulate operating conditions and provide an even more accurate classification of these materials. A Proctor compactor machine was applied to induce a top impact load more similar to the operating conditions of ballast. Pre-screened, sorted, washed, and dried samples of andesite aggregate from four quarries with different rock physics characteristics were used to conduct the test series. The impact load was applied with increasing numbers of blows, i.e., 64, 128, 256 and 1024. Several parameters and indexes were calculated to reveal different relationships, which had to be modified in some cases to obtain estimates as close as possible to those obtained in individual tests. The original Ballast Breakage Index seemed to be an appropriate measure of the change in ballast material quality during deterioration for over a decade. The original calculation method was not consistent with the newly introduced test method. Keeping the principle, however, a modified BBI index calculation method has been developed that fundamentally simplifies the calculation of ballast fragmentation. The whole series of measurements aimed to provide, by material and number of impacts, a series of fragmentation and degradation curves for each of the three repeated measurements, which would give the degradation of samples with different rock physics and grain sizes.

Open Access: Yes

DOI: 10.12700/APH.22.4.2025.4.9

Pulchellaobovella brunszvikae sp. nov.: the second species of the genus in Africa with the notes on the genus Pulchellaobovella Hirschmann, 1979 (Acari: Uropodina: Urodinychidae)

Sergey G. Ermilov Jenő Kontschán Rita Ábrahám

Publication Name: International Journal of Acarology

Publication Date: 2025-01-01

Volume: 51

Issue: 7-8

Page Range: 525-529

Description:

Herein, a new species, Pulchellaobovella brunszvikaesp. nov. (Mesostigmata: Uropodina: Urodinychidae), is described and illustrated based on two females and two males collected in Kenya. It is the second representative of the genus Pulchellaobovella in Africa. The new species differs from the already described Pulchellaobovella species in the presence of strongly sclerotized grooves on the dorsal shield, which are unique characters in this genus. A generic diagnosis and a new key to the known species are presented. Paper: http://www.zoobank.org/urn:LSIDurn:lsid:zoobank.org:pub:77E084D4-8256-4148-A500-4A336CCF4A8C New species: http://www.zoobank.org/urn:LSIDurn:lsid:zoobank.org:pub:6C6EE41C-F38F-4242-8063-9441FE96A430.

Open Access: Yes

DOI: 10.1080/01647954.2025.2571118

Implementing Nature-Based Solutions for Treatment of Winery's Wastewater and Sustainable Carbon-Footprint Reduction

Katalin Bene Attila Kálmán Mirtill Szombati

Publication Name: Chemical Engineering Transactions

Publication Date: 2025-01-01

Volume: 121

Issue: Unknown

Page Range: 19-24

Description:

Nature-based solutions can reduce the negative effects of climate change by mitigating the risk of droughts with water retention, increasing infiltration, controlling stormwater runoff and by decreasing atmospheric greenhouse gas emission. The carbon footprint of wastewater treatment plants is significant; the processes are energy-intensive and thus high CO2 emitters. The technology of wine making creates wastewater with extremely high organic content and is coupled with high carbon footprint. Its treatment poses challenges for wastewater plants. This study focuses on the wastewater of winemaking process and its negative effects on carbon-footprint and the wastewater management opportunities of the Csengőd wastewater treatment plant in Hungary. The traditional wastewater treatment and the potential implementation of a poplar plantation were assessed economically and environmentally. The energy consumption and the carbon footprint reduction were compared in the two cases to evaluate their sustainability. Significant energy savings and economic benefits can be achieved by the trade-off between traditional treatment and the use of nature-based solutions. The assessment is novel, because it evaluates all three sustainability pillars, considering: benefits with pay-off through technological processes, environmental aspects and additionally the interests of stakeholders. A poplar plantation can be used to pre-treat wastewater of a winery and thus effectively reduce the high organic concentration – thereby protecting the sensitive technologies of traditional wastewater plants. The trade-off results in annual energy savings of 61,823 kWh and CO2 emission reduction of 16,692 kg, which means financial savings. The direct sustainable benefits are € 287,824 over the 50-year life cycle in a small wastewater plant.

Open Access: Yes

DOI: 10.3303/CET25121004