Search Results (22,545)

Electric vehicles (EVs) are playing a crucial role in decarbonising the transportation industry by cutting down on toxic emissions from vehicles. Increasing the range of EVs is still a major hurdle in the widespread adoption of such vehicles, and serious efforts are underway across the globe in order to address this issue. A potential solution to this is the integration of small wind turbines with EVs to extract wind power and help charge the batteries. However, serious efforts in this regard are severely lacking in the published literature. This study aims to bridge this gap through systematic numerical investigations on a drag-based vertical-axis wind turbine (VAWT) installed on top of an EV. Utilising Computational Fluid Dynamic (CFD)-based solvers, the flow fields associated with the turbine are analysed in detail. Instantaneous and average power produced by the turbine have been critically evaluated over its entire operational range and at different vehicle speeds. The results obtained show that the VAWT has a peak power coefficient (Cp) of 0.46 at a tip speed ratio (λ) of 0.55. The average power produced by the VAWT at 30 mph, 50 mph, and 70 mph is about 160 W, 700 W, and 2 kW, respectively. Full article

The present study explored the dynamic effects of foliar biostimulants on cucumber (Cucumis sativus var. Centauro) accumulated yield curves using a novel statistical approach: Functional Data Analysis (FDA). Four treatments were tested: T1 (control, water), T2 (seaweed extract with N, K, B, Zn), T3 (high Mg, B, Zn), and T4 (T2 + T3). Yield was measured over four harvest cuts. FDA modelled cumulative yield as continuous functions. Functional principal component analysis identified one major mode of variation, revealing an accelerated yield response between the second and third cuts, especially for T4. A functional generalized regression detected significant treatment effects (p = 0.029), which were not detected by a traditional repeated-measures ANOVA (p = 0.074). The results showed that FDA captures subtle, time-dependent growth dynamics missed by conventional methods. The combination treatment (T4) maximized yield via early-phase acceleration, highlighting a synergistic biostimulant effect. FDA provided a superior analytical framework for understanding continuous crop responses to biostimulants. Full article

Under low wind speed conditions, conventional bluff body energy harvesters suffer from a single vibration mechanism and a narrow effective wind speed range, making it difficult to meet the continuous power supply demands of miniature electronic devices. In this paper, by systematically optimizing the number of triangular prisms N and the circumferential installation angle α, a parametrically adjustable star-shaped energy harvester (SEH) is proposed. The proposed structure consists of a cylindrical base with a tunable number of triangular prisms uniformly distributed along its circumference, aiming to reveal the regulation mechanism of the VIV-galloping coupling response and energy harvesting performance. Conceptual design and theoretical modeling of the SEH are first carried out. Then, three-dimensional fluid–structure interaction simulations are performed by varying N and α, and a prototype is fabricated for wind tunnel experimental validation. The results show that under the optimal parameter combination of N = 7 and α = 51.4°, the SEH achieves a maximum output voltage of 12.2 V at a wind speed of 3.41 m/s, with a maximum output power of 1.488 mW, and the effective wind speed range is broadened to 2.5~12.44 m/s. Compared with the conventional cylindrical energy harvester (CEH), the SEH (N = 7) increases the maximum output voltage by 44.38%, the maximum output power by 108.4%, and expands the effective wind speed range by 198.50%. Through systematic optimization of key geometric parameters, this study achieves synergistic regulation of flow-induced vibration modes and performance enhancement, providing a parametric design basis for efficient low-speed wind energy harvesting, which can promote the development of self-powered technologies for micro-sensors and IoT devices. Full article

The field inspection and ripeness detection of tomatoes in China remain heavily dependent on manual labor, while existing robotic solutions often exhibit limited functionality, poor environmental adaptability, prohibitive hardware costs, and unstable positioning accuracy. To address these limitations, this study proposes an intelligent tomato inspection robot that seamlessly integrates real-time ripeness recognition with precise spatial localization. Built upon a Raspberry Pi 5 core controller, the robot employs a lightweight, layered modular architecture designed to flexibly navigate complex agricultural environments. A comprehensive, multi-dimensional image dataset of tomato ripeness was constructed to train a three-category detection model based on the YOLOv8n architecture. Following 413 training epochs, the model demonstrated exceptional performance, achieving an overall mAP@0.5 of 87.8% and an mAP@0.5:0.95 of 72.7% on the held-out test dataset. In field inspections, the system achieved detection precisions of 82.22% for immature tomatoes, 92.66% for half-ripened tomatoes, and 100% for fully ripe tomatoes, successfully identifying all ripe tomatoes and satisfying the practical demands of field inspection. Furthermore, the integration of an Ultra-Wideband positioning system yielded an overall Root Mean Square Error of 0.231 m, successfully confining positioning errors to within 0.24 m to fully satisfy the stringent localization demands of crop-level inspection. Field evaluations confirmed that under optimal configurations, the robot can efficiently inspect a 50-m planting row in 10 min (±1 min) and maintains a continuous operational battery life of 2 h (±10 min). The core contribution of this work is the system-level integration and optimization of technologies for greenhouse agriculture. This integrated design achieves low hardware cost and high deployment flexibility, addressing longstanding challenges of labor-intensive inspection and delayed harvesting, and delivering a practical solution for intelligent tomato plantation management. Full article

Early and non-destructive identification of fungal contamination in cereals is essential to support post-harvest management, reduce economic losses, and mitigate food safety risks along the wheat supply chain. Among filamentous fungi, Alternaria spp. are widespread contaminants of durum wheat and producers of toxic secondary metabolites such as alternariol (AOH), whose early detection remains analytically challenging. The aim of this study was to evaluate the potential of near-infrared transmittance (NIT) spectroscopy as a rapid, non-destructive pre-screening tool for the early identification of Alternaria-contaminated durum wheat lots and associated AOH risk. Samples from three durum wheat cultivars were artificially inoculated with Alternaria spp. and monitored over time. NIT spectra (570–1100 nm) were acquired in transmittance mode and analyzed using partial least squares (PLS) regression, focusing on the 870–1100 nm spectral region. Clear and time-dependent spectral differences were observed between inoculated and control samples, with the strongest discriminative features at 834 and 966 nm. Classification performance was high, with area under the curve (AUC) values between 0.96 and 0.97. ELISA analysis confirmed progressive AOH accumulation in inoculated kernels, consistent with the observed spectral changes, while control experiments excluded autoclaving and visual grain damage as confounding factors. From an applied perspective, the results indicate that NIT spectroscopy can support post-harvest decision-making as a rapid pre-screening approach, enabling the prioritization of suspect wheat lots for confirmatory analytical testing. Multivariate analysis further confirmed the consistency of spectral differences across datasets. Full article

Plums are primarily sold fresh, but post-harvest softening and rotting can cause significant economic losses. Understanding quality changes across different maturity stages is crucial for meeting consumer demand for high-quality fruit. This study systematically analyzed the dynamic changes in the physicochemical properties, phenolic content, and cellular structure of ‘French’ plums during six growth and development stages (D1–D6), and comprehensively evaluated fruit quality using correlation analysis and principal component analysis (PCA). The results showed that firmness declined considerably with maturity, whereas the soluble solids content (SSC) increased and titratable acidity (TA) decreased. The peel color progressed from green to a purplish-red. The levels of sugars, such as glucose and fructose, increased, whereas those of major organic acids decreased. Phenolic content varied with developmental stage, with catechin and epicatechin peaking at the D3 stage (pre-color green stage), demonstrating exceptional antioxidant potential. At the D5 stage (purple stage), the fruit exhibits an ideal balance of sweetness, acidity and moderate firmness. Although at the D6 stage (full purple ripe stage), SSC reached its highest levels, fruit cell walls were compromised, vesicles ruptured, and firmness significantly decreased. At this stage, phenolic content declined, indicating that the fruit had attained full maturity. At this maturity level, the fruit should be promptly consumed or processed. Full article

As a key component of sugarcane harvesting machinery, the spiral sugarcane lifter (SSL) enhances harvesting quality by lifting lodged sugarcane (LSC) into a posture suitable for stalk-base cutting and feeding. To improve the SSL’s lifting performance for LSC, this study developed a rigid–flexible coupling (RFC) simulation model of the sugarcane–SSL interaction and conducted kinematic and force analyses to identify the main shortcomings of the original design. Critical structural and operational parameters affecting lifting performance–including the lifting roller pitch, roller diameter, roller inclination angle, and lifter shoe length—were redesigned using mechanism-based constraints and simulation-assisted evaluation. The optimized SSL exhibited increased lifting speed and stability under low–speed, severe–lodging conditions. Under side-forward lodging (side deflection angle = 30°), the average maximum vertical height of the centroid (VHC) increased by 40.36%, and paired comparisons across three simulated lodging-angle scenarios showed significant improvement. Field tests under severe lodging at 0.55 m/s (≈2 km/h) yielded an average absolute simulation–to–field error of 5.37%. These findings support the effectiveness of the proposed parameter redesign for the tested medium-size harvester, although further validation is required under higher forward speeds, greater biomass throughput, and more variable soil conditions. Full article

The contamination of cereals by mycotoxins represents a major concern due to their harmful effects on human health and food quality. The current study investigated the occurrence of major mycotoxins (AFB1, AFB2, AFG1, AFG2, OTA, ENA, ENA1, ENB, and ENB1) in 158 raw cereal samples (durum wheat, barley, and maize) collected from two Tunisian regions: Beja (continental region) and Mahdia (coastal region). Mycotoxins were extracted using the QuEChERS method and quantified by UHPLC–MS/MS. Several mycotoxins were detected at high levels across all the cereals. In the Beja region, durum wheat was contaminated with AFB1, AFG1, ENA, ENA1, ENB, and ENB1, with ENB being the most frequent (70%). Mahdia durum wheat was contaminated only with ENA, ENA1, ENB, and ENB1, with ENB1 being the most prevalent (22.6%). Barley from both regions was contaminated only with ENs. The ENB was the most frequent (Beja 66%, Mahdia 28.6%). Maize from Beja was contaminated by OTA and ENs, with ENA1 being the most frequent (22.5%), while maize from Mahdia was contaminated by AFB1, AFB2, AFG2, and ENs (AFB1 was the most frequent, 35%). All wheat samples contaminated with AFG1 (6.55%) exceeded the European Union maximum limit for AFs in cereals (4 µg/kg). Similarly, maize samples contaminated with AFB1 (17.5%), AFB2 (10%), and AFG2 (2.5%) exceeded the EU maximum limit for aflatoxins in maize (10 µg/kg). Additionally, maize samples contaminated with OTA (5%) exceeded the EU maximum limit for OTA in unprocessed cereals (5 µg/kg). The co-occurrence of multiple mycotoxins was observed in all cereal types, with up to six different mycotoxins detected in a single sample. Dietary risk assessment revealed high EDIs of AFB1, AFG1, and ENs through the consumption of wheat and barley by Tunisian adults. The calculated MOE values for AFB1 and AFG1 in wheat were below 10,000 (MOE = 1190 for AFB1 and 2.5 for AFG1), suggesting a potential health concern associated with dietary exposure. Despite this potential risk, AFB1 and AFG1 were detected in only 3% and 7% of the analyzed samples, respectively. These results highlight the need for regular monitoring and the establishment of regulations to control mycotoxins in Tunisian cereals. Full article

To protect the endangered Northern Spotted Owl, the U.S. Fish and Wildlife Service established extensive conservation areas across the Pacific Northwest (PNW). While this policy effectively contributed to the preservation of an endangered species, it also generated significant short- and long-term impacts on the U.S. forestry market. This study investigates the impact of federal timber harvesting restrictions in the Pacific Northwest in the early 1990s on the U.S. softwood market, particularly on softwood planting in the South. By constructing and analyzing a panel dataset covering 537 counties in seven southern U.S. states from 1977 to 2007, the research finds that timber-harvesting restrictions triggered by the listing of the Northern Spotted Owl as threatened led to a significant increase in softwood planting rates in the Southern U.S. Previous studies have shown that set-asides can shift timber harvesting from one region to another and raise prices in the short term. This study illustrates a different outcome of set-asides: tree planting. We argue that accounting for long-term investment responses, such as tree planting, is critical when evaluating the impacts of forest policies, as these can significantly alter estimates of net carbon balance and overall market outcomes. Full article

Ablation and harvesting are among the most labor-intensive and physically demanding operations in oil palm cultivation, often resulting in significant drudgery and safety concerns when performed manually through climbing or pole-assisted methods. To overcome these challenges, a motorized backpack-type machine was developed and evaluated for its field performance, ergonomics, and economic feasibility. The machine met required quality standards and exhibited satisfactory performance under field conditions, achieving average ablation and harvesting capacities of 286 inflorescences per day and 4.115 t day⁻¹, with actual field capacities of 0.727 ha h⁻¹ (ablation), 0.516 ha h⁻¹ (sickle), and 0.537 ha h⁻¹ (chisel), and field efficiencies of 81.23%, 76.3%, and 79.91%, respectively. Ergonomic evaluation indicated that operation of the machine falls within a moderate workload category, thereby reducing operator fatigue compared to manual methods. Economic analysis further revealed that the cost of operation was substantially reduced to 3.02 USD t⁻¹ and 60.40 USD ha⁻¹ year⁻¹, resulting in increased harvester earnings of 174.72% and 64.83% compared to climbing and pole harvesting methods, respectively. These findings demonstrate that the motorized backpack machine is a practical, efficient, and economically viable alternative to traditional techniques and minimizes drudgery while improving productivity and profitability in oil palm plantations. Full article

Logging causes damage on residual trees, with differing characteristics and severities. The causal agent, as well as the size and type of injury, is influenced by the type of machines, the harvesting technology adopted, and the machine operator. This study descriptively documents residual tree damage observed in two sledge-yarding operations conducted under contrasting stand and operational conditions: a beech stand managed with a full-tree system and a Scots pine stand managed with a cut-to-length system. Two stands were selected: the harvesting intensity was 50% in the coniferous stand (salvage logging) and 20% in the deciduous stand (thinning). In each stand, six 20 × 20 m plots (0.04 ha) were delineated to assess residual tree damage. In the two observed cases, the beech operation showed a higher proportion of damaged residual trees, 32.2%, than the Scots pine operation, 5.3%. In the deciduous stand, bark injuries were mainly slight wood exposure (75%), whereas in the coniferous stand, crushed bark (42.9%) was most frequent, followed by slight wood exposure (35.7%). No concerning damage to seedlings was detected. In general, the number of damaged trees and the severity of injuries were considerably lower than those typically observed when extracting with a cable skidder, and especially with an adapted farm tractor. To reduce mechanical damage to residual trees, protective devices can be deployed around trees at risk of root and stem injury. Another effective measure is to financially motivate workers to implement environmentally sound forest operations. Full article

The open fan as a highly efficient propulsion concept is a promising approach to reduce climate-damaging emissions in aviation. However, the increased vibroacoustic emissions of the fan resulting from the open design lead to elevated cabin noise. Energy harvesting resonators can be used to leverage the piezoelectric effect and to attenuate structural vibrations caused by the acoustic loading simultaneously. To evaluate the potential of a specific configuration of energy harvesting resonators, an investigation of the dynamic interaction between the airframe and the resonators is necessary. Therefore, the eigenmodes and eigenfrequencies of a representative stiffened plate are determined experimentally using modal analysis via laser scanning vibrometry. A finite element model of the stiffened plate with the resonator idealized as a mass–spring element is implemented. The stiffness of this simplified resonator model is calibrated by correlating simulated with experimental results following a model updating approach. Finally, an optimization framework designed to determine the optimal quantity and placement of resonators using the experimentally validated model and representative loads is implemented to maximize both vibroacoustic attenuation and energy harvesting efficiency. The resulting framework serves as a generalized optimization tool capable of systematically optimizing the resonator configuration based on airframe geometry and specified vibroacoustic loading scenarios. Full article

Enhancing egg production in geese without antibiotics remains a challenge in poultry science. This study compared the effects of Lactobacillus (LAB) and Bacillus (BAC) probiotics on laying performance, gut microbiota, and serum metabolism in Zhedong White geese. Birds were fed a control diet or diets supplemented with LAB or BAC. Egg production and quality were monitored throughout the trial. Serum metabolomics and fecal 16S rRNA sequencing were integrated with KEGG enrichment and correlation analyses to uncover functional mechanisms. Both probiotics improved laying performance and egg quality. Total egg production of the LAB group was 8.5% higher than that of the BAC group (p < 0.05). The LAB group’s advantage in egg production was consistent with its stronger activation of the steroid hormone biosynthesis pathway (elevated serum corticosterone and tetrahydrocorticosterone indicated an overall enhancement of steroidogenic flux). Simultaneously, the LAB group exhibited a more efficient conversion of L-phenylalanine to catecholamine precursors, which drove activation of the neuroendocrine reproductive axis. The BAC group showed more significant changes in nitrogen and energy metabolism pathways and a more pronounced expansion of energy-harvesting Firmicutes. These findings reveal two strain-specific regulatory pathways: LAB functions through the “aromatic amino acid–neuroendocrine–steroid hormone axis,” while BAC relies on the “gut microbiota–energy metabolism” pathway, with direct implications for the precise application of probiotics under antibiotic-free farming conditions. Full article

To address the low mechanization level, high labor intensity, and severe substrate disturbance in intertidal shellfish harvesting, a vibratory harvesting method based on local vibration-induced substrate fluidization was proposed, and a vibratory harvesting device for Mactra veneriformis was developed. Bench and intertidal field tests were conducted to systematically investigate the effects of vibration frequency, vibration pressure, and vibration amplitude on substrate fluidization, clam uplift, and harvesting performance. The single-factor results showed that all three parameters significantly affected the pore water pressure ratio, substrate viscosity, uplift distance, and harvesting rate, with better fluidization obtained at 8 Hz, 30 kPa, and 25 mm. A Box–Behnken response surface design was further used to establish quadratic regression models for these responses, and all models were highly significant with a non-significant lack of fit. The optimized parameter combination was 10 Hz, 35 kPa, and 25 mm, under which the predicted pore water pressure ratio and uplift distance were 101.3% and 97.2 mm, respectively, and the substrate viscosity was 1364 Pa·s. Field tests showed that the pore water pressure ratio remained above 85.3%, viscosity decreased to 1331–2639 Pa·s, shear strength decreased by 57.2–64.9%, and the average uplift distance at 100 mm burial depth reached 80–92 mm. The results indicate that vibratory harvesting can effectively promote substrate fluidization and reduce clam uplift resistance, providing a reference for the development of low-disturbance mechanized harvesting equipment for intertidal shellfish. Full article

In plant factories with artificial lighting (PFALs), spectral regulation serves as the predominant factor governing plant growth and development. The implementation of red-enriched spectral regimens during cultivation promotes biomass accumulation, whereas blue-dominant spectra enhance the biosynthesis of phytochemicals and nutritional compounds in plants. Nevertheless, systematic investigations into the effects of staged spectral regimens on both plant development and secondary metabolite biosynthesis remain limited. This study evaluated four distinct stage-specific dynamic lighting regimens (T1–T4) under a constant total photosynthetic photon flux density (PPFD) of 200 μmol·m⁻²·s⁻¹. The treatments utilized three distinct red-to-white photon flux ratios (R:W = 3:1, 1:1, and 1:3) administered sequentially during critical developmental phases of Pak choi: the seedling stage, the early growth stage (15 days after transplanting, DAT), and the late growth stage (16–30 DAT). The effects of these treatments on biomass production, morphological development, photosynthetic pigments, nutritional metabolites, antioxidant levels and radical quenching capacity were evaluated. The results demonstrated that the T4 treatment significantly enhanced biomass production, increasing shoot fresh weight by 51.3% compared to the T1 treatment at the late growth stage. The application of a higher red-light proportion (HR, R:W = 3:1) during the seedling stage significantly increased leaf area by 70% compared to the low red-light treatment (LR, R:W = 1:3). Regarding nutritional quality, while carotenoid content showed no significant differences among treatments, higher blue-light proportions selectively stimulated the biosynthesis of chlorophyll, vitamin C, and soluble proteins. Specifically, the T3 treatment enhanced certain traits during the early growth stage, whereas the T2 treatment best maintained specific antioxidant capacities (FRAP and flavonoids) at the late growth stage prior to harvest. Notably, nitrate levels were not significantly affected by the spectral shifts. This study establishes that the temporal modulation of red-to-white spectral ratios enables the targeted optimization of either crop yield (T4) or specific harvest-stage nutritional attributes (T2) in Pak choi. Full article