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Publications - 6289

Shear strength of stainless steel I-beams with sinusoidal corrugated webs

G. Hajdú Imre Cserpes

Publication Name: Structures

Publication Date: 2026-02-01

Volume: 84

Issue: Unknown

Page Range: Unknown

Description:

This paper presents an experimental and numerical investigation on stainless steel I-beams with sinusoidal corrugated webs. To characterise the shear resistance and failure mechanism, nine full-scale specimens fabricated from austenitic stainless steel (grade 1.4301) were subjected to three-point bending loading condition. The experimental results showed that at low slenderness ratios, the web could exceed its nominal yield strength. At the ultimate load level, initial local buckling occurred in a single corrugation wave. As the load increased further, the local buckling spread to the other waves as well and the post-buckling failure mode resembled global buckling. Based on the results of the experimental tests, advanced finite element models were developed and validated to conduct a comprehensive parametric study. The numerical analysis demonstrated that the shear buckling capacity of stainless steel girders with sinusoidal corrugated web exceeds the predictions of EN 1993–1–5:2006. On this basis, analytical expressions are proposed to account for the increased ultimate shear resistance. In addition, the accuracy of existing expressions for determining the elastic critical local shear buckling stress is evaluated, and a new formula is proposed. Statistical analysis shows that the proposed expressions provide improved accuracy within the investigated parameter ranges.

Open Access: Yes

DOI: 10.1016/j.istruc.2025.111036

Preliminary Study on Synergistic Effects of Humic Acid and Seaweed Extract on Cereal Crop Yield and Competitiveness with Wild Weed Beets (Beta vulgaris L.)

Viktoria Vona Husam S.M. Khalaf István Mihály Kulmány Ali Adnan Hassouni Husam S.M. Khalaf Zainulabdeen Khalaf Hashim Rusul R. Shakir

Publication Name: Plants

Publication Date: 2025-12-01

Volume: 14

Issue: 24

Page Range: Unknown

Description:

Crop–weed competition markedly reduces cereal yield. Integrative weed management approaches, involving the use of humic acid (HA) and seaweed extract (SWE), have gained attention as herbicide efficacy declines and environmental concerns grow. However, potential synergistic effects between HA and SWE have not yet been investigated. We evaluated the effects of HA, SWE, and their combination (HA+SWE) on the growth, yield, and competitive ability of cereals against wild weed beets (Beta vulgaris L.). A single-season field experiment was conducted using a split-plot design within a randomised complete block to assess the effects of treatment amendments on wheat, barley, and oats. The results showed that HA and HA+SWE organic amendments consistently improved grain yield and biomass across crop species. SWE responses varied across species, indicating species-dependent sensitivity. In addition, HA enhanced barley weed suppression, highlighting its dual roles in improving crop vigour and reducing weed proliferation. In contrast, SWE modestly increased spike length in oats, emphasising its effect on crop growth characteristics. Overall, these preliminary findings support targeted biostimulant use to enhance cereal yield and integrate weed management into sustainable cropping systems.

Open Access: Yes

DOI: 10.3390/plants14243770

Discrete time stability of augmented Lagrangian formalism based underactuated inverse dynamics control method

Ambrus Zelei R. Zana

Publication Name: JVC Journal of Vibration and Control

Publication Date: 2025-10-01

Volume: 31

Issue: 19-20

Page Range: 4445-4468

Description:

Stability problems of robotic systems arise sometimes suddenly, seemingly for no reason. The digital time sampling is often the main cause of these instabilities. Discrete models, which are capable of the prediction of stability, are available for low-degree-of-freedom template models of linear position and force control. However, for the inverse dynamics control of underactuated systems, the literature has a lack of generally applicable results related to the effect of time discretization. Several control approaches are available in the literature out of which a widely used one, the augmented Lagrangian formalism and its stability properties are analysed in this work. Theoretical stability properties are obtained for a generally usable, linear, underactuated, two-degree-of-freedom constrained template model. The actuator dynamics, the finite difference approximation of the feedback velocity and the filtering of the feedback data are considered in the model. These phenomena strongly affects the stability properties. The theoretically obtained stability maps are experimentally validated on an underactuated crane-like indoor robot. The position and orientation accuracy of the robot were assessed: the absolute position error was below 30 mm and the orientation error was below 3°.

Open Access: Yes

DOI: 10.1177/10775463241280339

Catalogue of the Uropodina species (Acari: Mesostigmata) described between 1993 and 2023

Jenő Kontschán

Publication Name: Acta Phytopathologica Et Entomologica Hungarica

Publication Date: 2024-09-06

Volume: 59

Issue: 1

Page Range: 29-62

Description:

All described Uropodina species (351) are listed from the last 30 years with the original occurrences. On continent level, the most of the described species are from Asia (121), from Central and South America (87) and from Africa (79). On country level, the most species were described from Ecuador (21), Vietnam (21), Kenya (18), Thailand (16), Costa Rica (15), China (14), Slovakia (14), Malaysia (14), Madagascar (14), Brazil (13), Indonesia (11), India (10) and Peru (10) and nine or fewer species were described from the other countries in the last 30 years. Trichouropoda pocsi Kontschán, 2004 (Comoro Islands) is a junior homonymous name of Trichouropoda pocsi Hirschmann & Wisniewski, 1987. The new replacement name for the T. pocsi Kontschán, 2004 is Trichouropoda pocstamasi nom. nov.

Open Access: Yes

DOI: 10.1556/038.2024.00216

Pontfelhők geometriai és attribútumtorzulásai

K. Kozma Szeverin Oláh Árpád Barsi

Publication Name: Geodezia Es Kartografia

Publication Date: 2025-01-01

Volume: 77

Issue: 3

Page Range: 18-26

Description:

The paper addresses geometric and attribute distortions in point clouds, which can arise at various stages of data acquisition and processing. The authors present the main sources of distortions—such as sensor limitations, platform movement, and environmental influences—and their impact on point density, data distribution, and attribute reliability. They detail statistical methods for quantitative evaluation of distortions (e.g., Getis–Ord Gi*, Moran’s I, Gini coefficient), which allow systematic measurement and correction of errors. The study emphasizes that analyzing and mitigating distortions is essential for creating more accurate spatial models and producing reliable geoinformatics analyses.

Open Access: Yes

DOI: 10.30921/GK.77.2025.3.3

Performance of Concrete Incorporating Waste Glass Cullet and Snail Shell Powder: Workability and Strength Characteristics

Majid Movahedi Rad Akindele Christopher Apata Udeme Udo Imoh

Publication Name: Buildings

Publication Date: 2025-07-01

Volume: 15

Issue: 13

Page Range: Unknown

Description:

This study investigates the combined use of waste glass cullet (WGC) and snail shell powder (SSP) as a sustainable binary cementitious system to enhance the mechanical performance and durability of concrete, particularly for rigid pavement applications. Nine concrete mixes were formulated: a control mix, four mixes with 5%, 10%, 15%, and 20% WGC as partial cement replacement, and four corresponding mixes with 1% SSP addition. Slump, compressive strength, and flexural strength were evaluated at various curing ages. Results showed that while WGC reduced workability due to its angular morphology (slump decreased from 30 mm to 20 mm at 20% WGC), the inclusion of SSP slightly mitigated this reduction (21 mm at 20% WGC + 1% SSP). At 28 days, compressive strength increased from 40.0 MPa (control) to 45.0 MPa with 20% WGC and further to 48.0 MPa with the addition of SSP. Flexural strength also improved from 7.0 MPa (control) to 7.8 MPa with both WGC and SSP. These improvements were statistically significant (p < 0.05) and supported by correlation analysis, which revealed a strong inverse relationship between WGC content and slump (r = −0.97) and strong positive correlations between early and later-age strength. Microstructural analyses (SEM/EDX) confirmed enhanced matrix densification and pozzolanic activity. The findings demonstrate that up to 20% WGC with 1% SSP not only enhances strength development but also provides a viable, low-cost, and eco-friendly alternative for producing durable, load-bearing, and sustainable concrete for rigid pavements and infrastructure applications. This approach supports circular economic principles by valorizing industrial and biogenic waste streams in civil construction.

Open Access: Yes

DOI: 10.3390/buildings15132161

Application of the Linear Programming Method in the Construction of a Mathematical Model of Optimization Distributed Energy

Laszlo Vasa Yuriy Bilan Marcin Rabe Katarzyna Widera

Publication Name: Energies

Publication Date: 2022-03-01

Volume: 15

Issue: 5

Page Range: Unknown

Description:

The Polish economy is facing a huge challenge regarding the future of energy in Poland. The current energy system is very inefficient, it consumes huge resources that, like countries with high energy efficiency, could be allocated to the development of low-carbon and renewable energy networks. At the moment, the Polish energy sector, related to the coal monoculture, lacks electricity and the entire transmission system is obsolete. The solution may be distributed energy, which can ultimately satisfy energy supplies in less urbanized areas and in rural areas, while guaranteeing the sustainable development of these areas. In order to take up the challenge of better understanding and explaining such a complex reality, it was decided that the research framework of this article will be distributed energy in the region. The aim of the article is to ensure energy security in the conditions of innovative, ecological and open to competition regional energy using local energy resources. Currently, it is believed that distributed energy can be an effective solution to the problem of conventional energy operation.

Open Access: Yes

DOI: 10.3390/en15051872

Investigation of Convective and Radiative Heat Transfer of 21700 Lithium-Ion Battery Cells

Szabolcs Fischer Gabor Kovacs Szabolcs Kocsis Szurke

Publication Name: Batteries

Publication Date: 2025-07-01

Volume: 11

Issue: 7

Page Range: Unknown

Description:

Due to their high energy density and power potential, 21700 lithium-ion battery cells are a widely used technology in hybrid and electric vehicles. Efficient thermal management is essential for maximizing the performance and capacity of Li-ion cells in both low- and high-temperature operating conditions. Optimizing thermal management systems remains critical, particularly for long-range and weight-sensitive applications. In these contexts, passive heat dissipation emerges as an ideal solution, offering effective thermal regulation with minimal additional system weight. This study aims to deepen the understanding of passive heat dissipation in 21700 battery cells and optimize their performance. Special emphasis is placed on analyzing heat transfer and the relative contributions of convective and radiative mechanisms under varying temperature and discharge conditions. Laboratory experiments were conducted under controlled environmental conditions at various discharge rates, ranging from 0.5×C to 5×C. A 3D-printed polymer casing was applied to the cell to enhance thermal dissipation, designed specifically to increase radiative heat transfer while minimizing system weight and reliance on active cooling solutions. Additionally, a numerical model was developed and optimized using experimental data. This model simulates convective and radiative heat transfer mechanisms with minimal computational demand. The optimized numerical model is intended to facilitate further investigation of the cell envelope strategy at the module and battery pack levels in future studies.

Open Access: Yes

DOI: 10.3390/batteries11070246

A Review of Modern Strategies for Enhancing Power Quality and Hosting Capacity in Renewable-Integrated Grids: From Conventional Devices to AI-Based Solutions

Eman S. Ali Adel A. Abou El-Ela Abdallah Nazih Adel A. Abou El-Ela Adel A. Abou El-Ela Asmaa A. Mubarak Adel A. Abou El-Ela Ragab A. El-Sehiemy

Publication Name: CMES Computer Modeling in Engineering and Sciences

Publication Date: 2025-01-01

Volume: 145

Issue: 2

Page Range: 1349-1388

Description:

Distribution systems face significant challenges in maintaining power quality issues and maximizing renewable energy hosting capacity due to the increased level of photovoltaic (PV) systems integration associated with varying loading and climate conditions. This paper provides a comprehensive overview on the exit strategies to enhance distribution system operation, with a focus on harmonic mitigation, voltage regulation, power factor correction, and optimization techniques. The impact of passive and active filters, custom power devices such as dynamic voltage restorers (DVRs) and static synchronous compensators (STATCOMs), and grid modernization technologies on power quality is examined. Additionally, this paper specifically explores machine learning and AI-driven solutions for power quality enhancement, discussing their potential to optimize system performance and facilitate renewable energy integration. Modern optimization algorithms are also discussed as effective procedures to find the settings for power system components for optimal operation, including the allocation of distributed energy resources and the tuning of control parameters. Added to that, this paper explores the methods to maximize renewable energy hosting capacity while ensuring reliable and efficient system operation. By synthesizing existing research, this review aims to provide insights into the challenges and opportunities in distribution system operation and optimization, highlighting future research directions that enhance power quality and facilitate renewable energy integration.

Open Access: Yes

DOI: 10.32604/cmes.2025.069507