Search Results (40)

The Northwestern Indian Ocean (NWIO) serves as a primary fishing ground for tuna longline fisheries, with bigeye tuna (Thunnus obesus) and yellowfin tuna (Thunnus albacares) constituting the main target species. Investigating their spatiotemporal distribution and relationship with environmental factors is of significant importance for fishery management and fishing. This study analyzed and compared the distribution patterns and environmental preferences of these two species across different depth layers, based on fisheries scientific survey data collected during the 2023/2024 and 2024/2025 fishing seasons. Key findings include: The hook rate in 2023/2024 was higher than in 2024/2025, and the hook rate for T. obesus exceeded that of T. albacares. T. obesus were predominantly concentrated within 63° E–69° E and 7° N–9° N, while T. albacares exhibited a broader yet more dispersed distribution range. T. obesus primarily occupied depth layers of 130–140 m (12.20%), 180–190 m (9.76%), and 270–280 m (9.76%). T. albacares were mainly found at 110–120 m (15%), 140–150 m (15%), and 200–210 m (15%). Both species exhibit distinct spatial clustering patterns, and their hotspot distribution areas are, respectively, 63° E–69° E, 5° N–10° N and 64° E–68° E, 0° N–4° N. Correlation analysis revealed significant relationships between T. obesus distribution and latitude, zooplankton abundance, water temperature at various depths, and chlorophyll a concentration. Our research provides reference for understanding the distribution of T. obesus and T. albacares across different water layers and their habitat preferences, laying a scientific foundation for achieving sustainable utilization of both species. Full article

Purpose: This study investigated the contribution of lower limb kinetics to punch performance in amateur boxing and examined the effects of fatigue on biomechanical efficiency. Methods: Ten male amateur boxers performed six punch types (jab, cross, left hook, right hook, left uppercut, right uppercut) under non-fatigued and post-fatigue conditions. Ground reaction force (GRF) and rate of force development (RFD) were measured using dual force plates, while punch outputs were assessed via a boxing force sensor. Fatigue was induced using a 9.5 min lower-body circuit. Results: Pre-fatigue, the cross punch generated the highest outputs for punch force (1475.42 N), GRF (947.54 N), and RFD (3973.38 N/s). Post-fatigue, punch force declined significantly across all punches (–4.26%, p = 0.027), with the greatest reductions in the cross and left hook. RFD responses were variable, with compensatory increases observed in some punches. Intra-individual analysis revealed greater fatigue-induced declines in the weakest punches (–9.84%, p = 0.001) compared with the strongest (–4.63%, p = 0.027). Conclusions: Lower limb force generation, particularly rear-leg drive, is critical to punch effectiveness and fatigue resilience. Conditioning programs should prioritise lower limb endurance while addressing performance variability across punch types. Full article

In this paper, a pattern reconfigurable quasi-Yagi antenna and array for 3-D full-space coverage is proposed. The antenna element consists of hook-shaped radiating patches, parallel-coupled branches, a circular metal patch, and a windmill-shaped metal ground, where four diodes are integrated with the feed lines. By switching the diodes’ operation states, the antenna element can operate in both omnidirectional and directional modes. In the omnidirectional mode, the antenna exhibits a bandwidth of 5.02–5.89 GHz, with a maximum gain of approximately 0.8 dBi. While in the directional mode, the antenna provides a bandwidth of 4.93–5.81 GHz and a maximum gain of 2.4 dBi. In array configuration, directional pattern reconfiguration for azimuth and elevation planes for 3-D full-space coverage can be achieved through excited elements selection and diode states switching, with a peak gain of 4.9 dBi in the directional mode and a pattern non-circularity of 3.1 dB in the omnidirectional mode. The proposed antenna offers advantages such as compact size, light weight, and excellent omnidirectionality, which has great potential in the application of unmanned aerial vehicles (UAVs). Full article

Composite geopolymer concrete (CGPC), is receiving growing attention in the construction sector for its sustainable nature, environmental benefits, and its valuable role in promoting efficient waste utilization. The strategic incorporation of reinforcing fibers into geopolymer concrete (GPC) matrices is critical for enhancing mechanical performance and meeting the durability requirements of high-performance construction applications. Although substantial research has focused on strength enhancement of fiber-reinforced geopolymer concrete (FGPC) individually, it has neglected practical considerations such as energy use for curing and life-cycle assessments. Thus, this study investigates the cost-effective aspects of FGPC cured under different regimes. Different cementitious binders were incorporated, i.e., fly ash (FA) and ground granulated blast-furnace slag (GGBS), in addition to alkaline activators (a combination of sodium hydroxide and sodium silicate), hooked-end steel fibers (HESFs), basalt fibers (BFs), and polypropylene fibers (PPFs), as well as aggregates (gravel and sand). The effect of different geopolymer-based materials, reinforcing fibers, and different curing regimes on the mechanical, durability, and economic performance were analyzed. Results showed that the applied thermal curing regimes (oven curing or steam curing) had a considerable impact on durability performance, compressive strength, and flexural strength development, especially for GPC mixes involving high FA content. Cost analysis outcomes suggested that the most affordable option is GPCM1 (100% FA without fibers), but it demonstrates low strength under ambient curing conditions; RGCM4 (100% GGBS and 0.75% HESF) provided the best strength and durability option but at higher material cost; RGCM7 (50% FA, 50% GGBS, and 0.75% HSF) exhibited a balanced choice since it offer satisfied strength and durability performance with moderate cost compared to other options. Full article

In this work, the synergistic effects of mineral admixtures and advanced mixing processes are systematically accounted for steel fibre-reinforced recycled aggregate concrete (SFR-RAC). It studies the improvement of performance optimization in SFR-RAC, inherently weak ITZ by adding 0.5% hooked steel fibres and replacing cement with ground granulated blast furnace slag (25–50%), fly ash (20–40%) and silica fume (7–14%). The efficiency of double-mixing (DM) and triple-mixing (TM) procedures were comprehensively evaluated. Results showed that mineral admixtures could improve mortar-aggregate interface bond, and the triple-mix technique contributed to such improvement. The maximum performance was observed for the combination of 7%SF with triple mixing (7%SF-TM), which presented increased compressive, tensile and flexural strengths by 7–18%, 12–29%, and 16–31% respectively. The durability was significantly improved, and the water resistance could increase by 53% with addition of 7%SF-TM, chloride penetration depth reduced by 86% when incorporated with 25%GGBS-TM, acid attack decreased by 84% with addition of 14%SF-TM. Microstructural analysis (SEM, XRD) confirmed that these enhancements stem from a denser matrix and refined ITZ due to increased C–S–H formation. This study confirms that the strategic integration of fibre reinforcement, pozzolanic admixtures and optimized mixing protocols presents a viable pathway for producing sustainable concrete from construction waste. Full article

Large-scale transitions to eco-friendly vehicle fleets present complex capital budgeting challenges, requiring the integration of extensive operational data with financial modeling while balancing economic profitability and environmental sustainability. Traditional approaches often struggle to manage this complexity and quantify the inherent trade-offs. This study develops and applies an innovative integrated accounting-and-finance framework to evaluate the economic and environmental implications of green fleet transition projects, explicitly quantifying the trade-off between profitability and sustainability. Focusing on waste vehicle replacement of Iren Spa, a leading European multi-utility company, we employ the recently developed Split-Screen Approach, a unified accounting-and-finance framework grounded in the laws of motion and conservation. It automatically reconciles pro forma financial statements and generates internally consistent valuation metrics, eliminating the manual adjustments and inconsistencies of traditional models. Its built-in diagnostic checks and scalability for highly complex datasets overcome the manual adjustments and inconsistencies inherent in traditional financial models. We process 2303 inputs across multiple “green” scenarios. This methodology integrates an Engineering Model, describing fleet evolution, operating costs, and CO₂ reduction, with a HookUp Model, which serves to transform scenarios into well-defined projects. The latter model is then integrated with a Financial Model that generates pro forma financial statements, incorporates financing and payout policies, and assesses economic profitability through Net Present Value (NPV) and consistent accounting rates of return. Together, these elements form a robust framework for managing complex data integration and analysis. Our research reveals a fundamental trade-off: enhanced environmental sustainability (measured by Net Green Value, NGV), which quantifies CO₂ reduction, is achieved at the expense of economic profitability, measured by NPV. This financial sacrifice is captured by the Net Value Curve, a Pareto frontier, while the NPV-to-NGV ratio provides “shadow prices” for CO₂ reduction, revealing the financial cost per unit of sustainability gained. Based on 21 project scenarios and additional sensitivity analyses on financial inputs and energy prices, the results confirm a decreasing relationship between NGV and NPV. This study makes three main contributions: (1) it demonstrates the practical application of the Split- Screen Approach for capital budgeting under complexity, (2) it introduces the Net Value Curve framework as a useful tool for visualizing and quantifying the trade-off between profitability and sustainability, (3) it provides managers and policymakers actionable insights, supporting more informed decisions in green fleet transition planning where economic and environmental objectives may conflict. The findings provide managers and policymakers with a rigorous and transparent accounting-and-finance framework that enhances the reliability of capital budgeting decisions compared with traditional financial modeling, while offering a Paretian frontier for evaluating environmental trade-offs. Full article

Particle Swarm Optimization (PSO) is a metaheuristic optimization technique based on population behavior, inspired by the movement of a flock of birds or a school of fish. In this method, particles move in a search space to find the global minimum of an objective function. In this work, a modified PSO algorithm written in Fortran 90 is proposed. The optimized structures obtained with this algorithm are compared with those obtained using the basin-hopping (BH) method written in Python (3.10), and complemented with density functional theory (DFT) calculations using the Gaussian 09 software. Additionally, the results are compared with the structural parameters reported from single crystal X-ray diffraction data for carbon clusters ${\mathrm{C}}_n$(n = 3–5), and tungsten–oxygen clusters, ${\mathrm{WO}}_n^{m-}$(n = 4–6, $m=2,4,6$). The PSO algorithm performs the search for the minimum energy of a harmonic potential function in a hyperdimensional space $\in {\mathbb{R}}^{3N}$ (where N is the number of atoms in the system), updating the global best position ( $g_{best}$) and local best position ( $p_{best}$), as well as the velocity and position vectors for each swarm cluster. A good approximation of the optimized structures and energies of these clusters was obtained, compared to the geometric optimization and single-point electronic energies calculated with the BH and DFT methods in the Gaussian 09 software. These results suggest that the PSO method, due to its low computational cost, could be useful for approximating a molecular structure associated with the global minimum of potential energy, accelerating the prediction of the most stable configuration or conformation, prior to ab initio electronic structure calculation. Full article

Predicting the flexural behavior of fiber-reinforced ultra-high-performance concrete (UHPC) remains a significant challenge due to the complex interactions among numerous mix design parameters. This study presents a machine learning-based framework aimed at accurately estimating the modulus of rupture (MOR) of UHPC. A comprehensive dataset comprising 566 distinct mixtures, characterized by 41 compositional and fiber-related variables, was compiled. Seven regression models were trained and evaluated, with Random Forest, Extremely Randomized Trees, and XGBoost yielding coefficients of determination (R²) exceeding 0.84 on the test set. Feature importance was quantified using Shapley values, while partial dependence plots (PDPs) were employed to visualize both individual parameter effects and key interactions, notably between fiber factor, water-to-binder ratio, maximum aggregate size, and matrix compressive strength. To validate the predictive performance of the machine learning models, an independent experimental campaign was carried out comprising 26 UHPC mixtures designed with varying binder compositions—including supplementary cementitious materials such as fly ash, ground recycled glass, and calcium carbonate—and reinforced with mono-fiber (straight steel, hooked steel, and PVA) and hybrid-fiber systems. The best-performing models were integrated into a hybrid neural network, which achieved a validation accuracy of R² = 0.951 against this diverse experimental dataset, demonstrating robust generalizability across both material and reinforcement variations. The proposed framework offers a robust predictive tool to support the design of more sustainable UHPC formulations incorporating supplementary cementitious materials without compromising flexural performance. Full article

Hub motor-driven vehicles (HMDVs) suffer from poor handling and stability due to an increased unsprung mass and unbalanced radial electromagnetic forces. Although traditional ground-hook control reduces the dynamic tire load, it severely worsens the body acceleration. This paper presents a generalized ground-hook control strategy based on impedance transfer functions to address the parameter redundancy in structural methods. A quarter-vehicle model with a switched reluctance motor wheel hub drive was used to study different orders of generalized ground-hook impedance transfer function control strategies for dynamic inertial suspension. An enhanced fish swarm parameter optimization method identified the optimal solutions for different structural orders. Analyses showed that the third-order control strategy optimized the body acceleration by 2%, reduced the dynamic tire load by 8%, and decreased the suspension working space by 22%. This strategy also substantially lowered the power spectral density for the body acceleration and dynamic tire load in the low-frequency band of 1.2 Hz. Additionally, it balanced computational complexity and performance, having slightly higher complexity than lower-order methods but much less than higher-order structures, meeting real-time constraints. To address time-domain deviations from generalized ground-hook control in semi-active systems, a dynamic compensation strategy was proposed: eight topological structures were created by modifying the spring–damper structure. A deviation correction mechanism was devised based on the frequency-domain coupling characteristics between the wheel speed and suspension relative velocity. For ride comfort and road-friendliness, a dual-frequency control criterion was introduced: in the low-frequency range, energy transfer suppression and phase synchronization locking were realized by constraining the ground-hook damping coefficient or inertance coefficient, while in the high-frequency range, the inertia-dominant characteristic was enhanced, and dynamic phase adaptation was permitted to mitigate road excitations. The results show that only the T0 and T5 structures met dynamic constraints across the frequency spectrum. Time-domain simulations showed that the deviation between the T5 structure and the third-order generalized ground-hook impedance model was relatively small, outperforming traditional and T0 structures, validating the model’s superior adaptability in high-order semi-active suspension. Full article

If modern Western disciplinary structures, laid forth by Dilthey and others in the 19th century, have helped structure the world in ways that bring about climate change and gross economic inequities (along with many “good” things such as vaccines and some modern comforts), how might we re-structure our thinking and learning in ways that address these violent lacunae? What does it mean to educate in a truly globalized world that is facing climate change, extinction, and growing injustice? The answer to that surely cannot be “more of the same”. Following the work of critical theorists and the ideas of Paulo Freire and bell hooks, among others, this essay argues that education should be about imagining and working toward a more just and ecologically sound version of the planetary future in a way that is attentive to as much input as possible from multiple perspectives (human and non). The goals of such an education are connective, grounding, and encountering “others” rather than reductive, productive, and geared toward technology transfer. What would it mean to undiscipline or open our disciplinary categories in ways that reattune us to the changing, entangled planet of which we are a part? What will it take to develop planetary humanities and technologies? If humans are not exceptions to the rest of the natural world, and if the nonhuman world is not just dead matter to be used toward human ends, then how do we go about re-grounding our epistemologies within the planet, rather than continuously thinking “out of this world”? The first part of this essay offers a critique of the reductive and productive model that turns the world into a “standing reserve” for use by some humans. The second part of the essay outlines some principles for knowledge that are more connective, grounding and enable us to counter the multiple others within the planetary community. Such “planetary” knowledge reminds humans of the humus of our humanity, connects us to other life found through compassion (to suffer with), reminds us of the justice of good company (sharing of bread/resources), and focuses on the playfulness of public, political conversations (the ability to be converted to another’s point of view). In the third part, I suggest some grounded metaphors for planetary thinking: wild and slow thinking, elemental and grounded thinking, and creaturely and mycelium thinking. Full article

The electrification trend characterizing the current automotive industry creates opportunities for the implementation of innovative functionalities, enhancing aspects of energy efficiency and vehicle dynamics. Active vehicle suspensions are an important subsystem in this process. To enable proper suspension control, vehicle sensors can be used to measure the system’s response and, in some cases, preview the road conditions and the presence of possible obstacles. When assessing the performance of a suspension system, the speed bump crossing represents a challenging maneuver. A suitable trade-off between comfort and road holding must be found through different phases of the profile. The proposed work uses a fixed-gain observer obtained from Kalman filtering to identify road unevenness and adapt the control strategy when the vehicle travels through a bump. To this end, the obstacle is identified through the use of affordable sensors available in high-end vehicles: accelerometers, inertial measurement units, and stroke sensors. The proposed technique is also affordable from the computational point of view, thus enabling its use in common microprocessors tailored for the automotive field. The bump identification technique is validated through experimental data captured in a vehicle demonstrator. Subsequently, numerical results show that the proposed technique is able to enhance comfort while keeping road holding and attenuating the transient after taking the bump. Full article

The work presented in this paper is to be read within the context of a connected autonomous vehicle (CAV). This context makes it possible to consider dividing the overall operational domain (operational design domain: ODD) of the vehicle into three sub-domains, relating to the areas of comfort (ODD1), road-holding (ODD2), and emergency situations (ODD3). Thus, based on information from the CAV’s proprioceptive and exteroceptive sensors, in addition to information from the infrastructure and other vehicles, supervision makes it possible, at any time, to identify the ODD in which the vehicle is located and to propose the most appropriate strategy, particularly for suspension control. Work already carried out by the authors made it possible to determine a crone sky hook (CSH) strategy for suspension control, 100% comfort-oriented for ODD1, a mixed crone sky hook—crone ground hook (CSH-CGH) strategy, oriented towards road-holding for ODD2, and a CGH strategy oriented towards safety for ODD3. In this paper, a comparative study focusing on security (ODD3) is presented. It concerns two versions of the CGH strategy (nominal CGHN and generalized CGHG). More precisely, for the comparative study to be meaningful, the control loops of the two versions have the same speed (iso-speed constraint), and the performance indices are normalized with respect to the values obtained in fault mode when the actuator is faulty. Notably, the CGHG version is part of the dynamics of fractional systems. Full article

This paper investigates the potential of negative stiffness suspensions for enhanced vehicle vibration isolation. By analyzing and improving traditional control algorithms, we propose and experimentally validate novel skyhook, groundhook, and hybrid control strategies for suspensions with negative stiffness characteristics. We establish pavement models, incorporate negative stiffness into suspension modeling, and develop a performance evaluation index. Our research identifies shortcomings of classical semi-active control algorithms and introduces a new band selector to combine improved control methods. Simulation results demonstrate that the proposed semi-active suspension control strategy based on negative stiffness effectively reduces body vibration and enhances vehicle ride performance. Full article

Despite numerous studies of single piles and practical experience with their application, methods for calculating settlements of pile foundations remain limited. The existing objective need for specialized methods of pile foundation settlement calculation that take into account the rheological properties of the base soils is becoming more and more important, especially in the construction of unique objects in complex ground conditions. When predicting the stress–strain state of the pile–raft-surrounding soil mass system, it is allowed to consider not the entire pile foundation as a whole, but only a part of it—the computational cell. In the present work, we have solved the problems of determining the strains of the computational cell consisting of the pile, the raft and the surrounding soil according to the column pile scheme and hanging pile scheme, on the basis of the Kelvin–Voigt rheological model, which is a model of a viscoelastic body consisting of parallel connected elements: Hooke’s elastic spring and Newtonian fluid. According to our results, we obtained graphs of the dependence of strains of the computational cell on time at different pile spacing and different values of coefficients of viscosity of the surrounding soil, and a formula for calculating the reduced modulus of deformation of the pile. The results of the present study can significantly improve the accuracy of calculations during construction on clayey soils with pronounced rheological properties and, as a result, increase the reliability of pile structures in general. Full article

Jiangsu is a province in China and has the highest frequency of tornado occurrences. Studying the meteorological background and mechanisms of tornado formation is crucial for predicting tornado events and preventing the resulting disasters. This paper analyzed the meteorological background, instability mechanisms, and lifting conditions of the two Enhanced Fujita Scale level 2 (EF2) and above tornadoes that occurred in southern Jiangsu on 14 May 2021 (“5.14”) and 6 July 2020 (“7.06”) using ERA5 reanalysis data. Detailed analyses of the internal structure of tornado storms were conducted using Changzhou and Qingpu radar data. The results showed that (1) both tornadoes occurred in warm and moist areas ahead of upper-level troughs with significant dry air transport following the cold troughs. The continuous strengthening of low-level warm and moist advection was crucial in maintaining potential instability and triggering tornado vortices. The 14 May tornado formed within a low-level shear line and a warm area of a surface trough, while the 6 July tornado occurred at the end of a low-level jet stream, north of the eastern section of a quasi-stationary front. (2) The convective available potential energy (CAPE) and K indices for both tornado processes were very close (391 for “5.14” and 378 for “7.06”), with the lifting condensation level (LCL) near the ground. The “5.14” showed greater instability and more favorable thermodynamic conditions, with deep southwesterly jets at the mid-level shear line producing rotation under strong convergent action (convergence center value exceeding −1 $\times {10}^{-4}$${\mathrm{s}}^{-1}$). In contrast, the “7.06” was driven by super-low-level jet stream pulsations and wind direction convergence under the influence of the Meiyu Front (convergence center value exceeding −1.5 $\times {10}^{-4}$ ${\mathrm{s}}^{-1}$), resulting in intense lifting and vertical vorticity triggered by a surface convergence line. (3) The “5.14” tornado process involved a supercell storm over a surface dry line experiencing tilting due to strong vertical wind shear, which led to the formation of smaller cyclonic vortices near a hook echo that developed into a tornado. The “7.06” developed on a bow echo structure within a mesoscale convective system formed over the Meiyu Front, where dry air subsidence, entrainment, and convergence of the southeast jet stream triggered a “miniature” supercell. The relevant research results provide a reference for the prediction and early warning of tornadoes. Full article