Search Results (740)

Long-term cold exposure reduces livestock welfare and productivity in Inner Mongolia. This study assessed cold stress effects on 60 two-month-old female Dorper × Mongolia lambs allocated to four sheltering conditions (n = 15): indoor pens with enclosed housing (IP), outdoor pens (OP), house with playground pens (OPP), and polytunnel pens (PP). Compared with IP, OP exhibited significantly lower temperature, humidity, CO₂ concentration, NH₃ concentration, and WCI, and significantly higher wind speed and solar radiant heat (p < 0.001). Humidity, CO₂ concentration, and NH₃ concentration in PP was lower than in IP, but higher than in OP (p < 0.001); temperature, wind speed, and WCI did not differ significantly between PP and IP. ADG was significantly lower in OP and OPP than in IP (p < 0.001), whereas PP did not differ from IP. F:G was higher in OP than in IP and PP (p = 0.040). Feeding duration had significant effects on ACTH, leptin, T₃, T₄, TP, urea, TG, NEFA, LDL, and HDL concentrations. Rearing environment significantly affected GLU, ALB, LDH, and TG. Feeding duration × sheltering conditions interaction significantly influenced ACTH, TP, ALB, urea, LDH, TG, LDL, and HDL. OP induced cold stress and dysfunction, while IP and PP produced milder responses. PP raised indoor temperatures substantially, and is thus optimal for winter lamb production. Full article

Atlantic salmon (Salmo salar) is an important dietary source of health-promoting long-chain polyunsaturated fatty acids (PUFAs). As rearing conditions significantly influence fillet quality, this study evaluated the effects of warm and cool rearing temperature and photoperiod regimes on salmon growth, lipid profiles, and antioxidant capacity. Atlantic salmon (210 days old) were reared for 92 days under low temperature (14 °C, 12 h light) or high temperature (21 °C, 24 h light) conditions to simulate relevant seasonal conditions, winter and summer respectively. At day 302, conditions were reversed to create low-to-high (L→H) and high-to-low (H→L) treatments, continuing until day 362. Growth parameters, muscle lipid content, fatty acid profile, and antioxidant activity were measured at 302 and 362 days. Lipid content and fatty acid profile were also measured based on fillet location and fish sex. High rearing temperatures accelerated weight gain and increased total and neutral lipid contents, but elevated saturated fatty acids (SFA) and decreased PUFAs in structural polar lipids. High temperatures also significantly increased antioxidant activity, indicating elevated oxidative stress. Conversely, low temperatures suppressed growth but preserved essential PUFAs and maintained oxidative stability. Following the temperature shift, the H→L group had enriched polar lipids with PUFAs and maintained oxidative stability. On the other hand, L→H group showed lower PUFAs accumulation in polar lipid and enhanced oxidative stress. Total lipid content was higher in the head region, followed by the middle and tail sections of the fillet. However, fatty acid composition remained largely uniform across all three sections of the fillet. There were no significant differences in total lipid content between fish sexes. In conclusion, production efficiency and nutritional quality can be optimized by initially rearing salmon at high temperatures to promote rapid growth, followed by low temperature finishing phase to increase essential PUFA content and maintain oxidative stability. Full article

The load characteristics of the helicopter tail rotor system are critical to flight safety and handling performance, and flight testing remains the most direct and reliable means to obtain authentic load data. In this paper, the well-established Wheatstone bridge strain measurement method is adopted to carry out accurate load testing on the helicopter tail rotor system. The tail rotor assembly mainly consists of the tail rotor shaft, pitch link, and tail rotor blades, which undertake different load transfer tasks during flight. Under actual operating conditions, the tail rotor shaft bears significant axial tension as well as combined lateral and vertical bending moments; the pitch link is primarily subjected to alternating axial tension and compression; and the tail rotor blades withstand complex loads including flapping bending, lagwise bending, and torsional moments. According to the distinct stress characteristics and force transmission paths of each component, targeted flight test maneuvers are reasonably designed. These maneuvers include steady-level flight at low, medium, and high speeds, zigzag climbing flight, near-ground side-rear flight, as well as deceleration-to-sprint and obstacle slope maneuvers specified in ADS-33E. Key flight parameters are selected for in-depth analysis to reveal the load distribution and dynamic variation patterns of the tail rotor under typical operating conditions. On this basis, a helicopter load risk test point matrix is established to identify high-risk working conditions and key monitoring positions. This study provides a solid theoretical and data foundation for subsequent flight test monitoring and structural strength verification. It effectively reduces flight test risks, improves monitoring efficiency and accuracy, and helps cut down the human, material, and financial costs associated with flight test monitoring. The research results can also provide important references for the design optimization and safety evaluation of helicopter tail rotor systems. Full article

Contemporary vehicle development, particularly for overactuated platforms, demands design methodologies that bridge the gap between high-level performance targets and hardware selection. Existing physics-based models, while essential, offer limited utility for this systems-level design task. This paper introduces a novel analytical framework for vehicle lateral dynamics, predicated on a reformulated single-track model that integrates the concept of tire-specific slip. The derived specific slip-based bicycle model enables a comprehensive frequency-domain analysis of handling characteristics, articulated through three fundamental metrics: the front and rear axle specific slips and the vehicle wheelbase. Our results quantify the influence of these parameters on key handling attributes, including stability, responsiveness, and roll susceptibility. This work provides a constitutive tool for the model-based design of next-generation vehicles, enabling the a priori selection and optimization of chassis hardware to meet predefined performance objectives and informing the synthesis of advanced motion control systems. Full article

To enhance the propulsion efficiency of near-space high-altitude unmanned aerial vehicle under low-density conditions and to gain a deeper understanding of the aerodynamic characteristics of contra-rotating propellers under complex interference, this study focuses on a high-altitude contra-rotating propeller propulsion system. A systematic investigation is conducted on the influence of design variables and flow characteristics. Considering the distinctive features of high-altitude environments, including low Reynolds numbers, high induced velocity ratios, and strong mutual interference between front and rear rotors, a numerical simulation method for contra-rotating propellers is established. The aerodynamic performance and typical flow structures are analyzed and compared with conventional propeller configurations to elucidate the aerodynamic advantages of contra-rotating propellers. Furthermore, key design variables such as axial distance, pitch angles of the front and rear propellers, and rotational speed matching are systematically examined to assess their effects on aerodynamic characteristics. Comparative analysis of axial velocity distributions reveals the interaction mechanisms between front and rear rotors under different parameter combinations and identifies the dominant factors influencing aerodynamic performance. The results indicate that rational matching of geometric parameters between front and rear rotors can effectively mitigate adverse interference, optimize wake structures, and improve the overall aerodynamic performance of contra-rotating propellers at high altitudes. These findings provide theoretical guidance and engineering references for the aerodynamic design and parameter selection of high-altitude contra-rotating propeller systems. Full article

The escalating demand for sustainable, nutrient-dense feeds underscores the need to valorize the agro-industrial byproducts utilizing innovative bioconversion strategies. In this context, we have studied the feasibility of incorporating tomato (Solanum lycopersicum) cultivation residues into Black Soldier Fly (BSF) larvae diets to produce high-protein insect meals. These residues are known to contain the naturally occurring toxic steroidal alkaloids tomatidine and α-tomatine, prohibiting their incorporation into human and animal diets. Herein, the tomato cultivation biomass was dried and mill-ground, and its varying volumes were incorporated into standard poultry feed (seven diet levels with 0–100% biomass inclusion) and tested in BSF-larvae-rearing trials to produce insect meals. The optimal results with respect to larvae growth, protein accumulation (highest value = 30.61%), lipid–fiber content, and antioxidant capacity were determined for insect meals obtained from BSF larvae reared with a ration composed of 40% tomato plant biomass. In addition, the toxicity of this insect meal was substantially low, as a consequence of the observed groundbreaking reduction in the contained toxic steroidal alkaloids α-tomatine and its aglycone tomatidine. The results herein reveal the efficacy of the BSF-larvae-rearing process in acting as a biological filter for the bioconversion of the toxic tomato cultivation waste into a functional, safe, and protein-rich livestock feed, supporting the principles of a circular economy. Full article

The black soldier fly, Hermetia illucens (Linnaeus, 1758), is a globally recognized resource insect for waste bioconversion and sustainable resource provision. Understanding its larval sensory system is key to explaining feeding and environmental perception behaviors. This study used scanning and transmission electron microscopy to analyze the types, distribution, ultrastructure, and developmental consistency of sensilla on larval cephalic appendages. Five sensilla types were found on antennae, sensilla basiconica I–II, sensilla twig basiconica I–II, and sensilla campaniformia, each type comprising 2–6 sensilla. Mouthparts harbored ten types, including sensilla twig basiconica III–V, sensilla placodea, sensilla ligulate, sensilla digitiformia, sensilla trichodea, and sensilla chaetica I–III, with 2–9 sensilla per type. All sensilla showed constant numbers and positions throughout larval development. Ten sensillum types with cuticle pores were innervated by 2–6 sensory neurons, primarily suggesting chemoreceptors; these were concentrated at the tips of antennae and maxillary palps. Sensilla digitiformia on the palps possessed a non-porous cuticle and a single sensory cell, indicative of a thermo-/hygroreceptive role. Sensilla chaetica and trichodea, with non-porous cuticles and no dendrites, were mechanosensory. These results reveal the morphofunctional basis of larval sensation, supporting chemoreception studies and optimizing rearing via behavioral modulation. Full article

The use of olive by-products in livestock farming is a valuable resource, given their high levels of bioactive compounds with antioxidant and health-promoting properties. This preliminary study adopted an integrated approach to evaluate the influence of dietary Olea europaea L. polyphenols on animal welfare, physiological stress response, intestinal morphofunctional traits, and meat quality in Neroametà finishing pigs, a novel Casertana × Large White genetic line (Neroametà). Thirty pigs reared under extensive farming conditions were randomly allocated to two groups (n = 15): a control group fed a standard diet (C) and a treatment group (OL) supplemented with 300 mg/head/day of olive polyphenolic extract for 90 days. The study focused on the systemic correlation between host health and product quality. Meat composition, rheological properties, meat antioxidant activity, stress parameters, and fatty acid profiles of the longissimus lumborum and psoas major muscles were analyzed. Results showed that the OL diet significantly modulated the HPA axis, as evidenced by a marked reduction in plasma ACTH and cortisol levels, alongside improved antioxidant status. These physiological changes were positively associated with a trophic effect on the intestinal mucosa, characterized by increased villus height and a more favorable villus/crypt ratio. Regarding meat quality, the OL group exhibited superior oxidative stability, optimized pH decline, and an improved intramuscular fatty acid profile (increased MUFA and n-3 PUFA, reduced SFA). Despite the pilot scale of 30 animals, these findings provide a solid foundation for characterizing the Neroametà breed. In conclusion, Olea europaea L. polyphenols act as a multi-level modulator, enhancing physiological resilience and meat quality, offering a sustainable strategy for high-quality pork production in line with circular economy and One Health principles. Full article

Traditional simulation work often starts from the study of the impact of a single factor on device performance to obtain the optimal value of that factor and then regards the combination of the optimal values of each factor as the optimization condition. Obviously, this approach ignores the impacts of the interactions among factors on device performance. To address this issue, this paper uses Quokka3 v2.6.0 and JMP Pro 17.0.0 to perform device simulation and parameter optimization research on tunnel oxide passivated back contact (TBC) solar cells. First, Quokka3 was employed to investigate the effects of silicon wafer properties, rear-side passivation and contact characteristics, and rear-side geometry on the performance of TBC solar cells. Subsequently, a total of 625 simulations were performed by using Quokka3 with four factors (wafer thickness, wafer resistivity, P/N ratio, and pitch) at five levels. Finally, JMP Pro was used to analyze the simulation results statistically. It was found that the pitch, P/N ratio, quadratic power terms, quadratic interaction terms except the interaction between wafer thickness and resistivity, cubic power terms, and some cubic interaction terms all have significant impact on power conversion efficiency (PCE). JMP Pro predicted that the TBC solar cell could achieve the maximum PCE of 26.784% under the conditions of wafer thickness = 143.25 μm, wafer resistivity = 1.09 Ω·cm, P/N ratio = 1.94, and pitch = 380 μm. Full article

The bollworm/corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), is one of the most economically damaging crop pests in North America. Colonies of H. zea are notoriously difficult to maintain and frequently collapse in laboratory rearing. The persistent difficulty in maintaining healthy H. zea colonies has become a major obstacle to performing many research activities on the insect. To optimize colony maintenance, six populations were evaluated across three trials and six tests examining pupal maturity at diet removal, adult emergence synchrony, and cohort size at mating and reproduction. Females emerging from mature pupae produced more eggs than those from mid-aged (5–7 d) or young pupae (0–2 d). Synchronizing male and female emergence within one day yielded higher mating frequency, spermatophore transfer, and progeny, whereas a two-day difference reduced these metrics by 45–67%. Adult cohort size also influenced the outcomes, with ≥10 males and ≥10 females per cage enhancing reproductive success. Most matings occurred on nights 2–3, peaking within 2.5 h after lights off. Positive correlations were observed among mating frequency, spermatophore transfer, and progeny production. Overall, optimal performance was achieved by removing pupae only at maturity, synchronizing adult emergence within one day, and maintaining larger adult cohorts. These findings should establish key conditions to improve the mating success, reproduction, and laboratory rearing of H. zea. Full article

Brackish aquaponics is expected to be a promising approach to sustainable food production, integrating saline water resources with simultaneous co-cultivation of fish and halophytes. The present study investigated the effects of three feeding ratios (FR1.5: 1.5%, FR3: 3%, and FR6: 6% b.w/d) on the growth performance of European sea bass (Dicentrarchus labrax) and glasswort (Salicornia europaea) co-cultured in three autonomous one-loop recirculation aquaponic systems (180 L each) at 20 ppt salinity over 78 days. Each system comprised three fish-rearing tanks connected to a two-stage sump filter and a nutrient film technique (NFT) hydroponic subsystem. Sea bass fed at FR3 achieved significantly higher weight gain, specific growth rate, and feed conversion efficiency than FR1.5. At FR6, feed consumption nearly doubled compared to FR3 (3.79 vs. 1.91 g), yet the feed conversion ratio increased from 0.79 to 1.65, and protein efficiency ratio declined from 3.80 to 1.91, indicating overfeeding effects. Regarding glasswort, FR6 produced significantly higher chlorophyll a content and plant biomass, whereas FR1.5 showed superior ammonia removal efficiency. Overall, FR3 provided the best balance between fish growth, plant yield, and water quality maintenance. These findings highlight the critical role of feeding management in brackish aquaponics in order to optimize nutrient coupling between fish and halophyte production. Full article

Aphids are among the most significant agricultural pests worldwide. Artificial diets are a critical foundation for aphid physiological and biochemical research and the development of pest control technology. However, their phloem sap-feeding habits, extraoral digestion characteristics, and host specificities pose numerous challenges to the development of artificial diets for aphids, including population degradation, reduced fecundity during long-term rearing, and a lack of methodological diversity in dietary formulation research. In this review, we summarize the research on artificial diets for aphids, encompassing the history of artificial rearing, rearing methods, and nutritional composition analysis of these diets. Furthermore, we discuss the optimization of diet formulations based on aphid digestive enzymes and symbiotic bacteria. We aim to synthesize successful developments of artificial diets for aphids and extend their application to diverse aphid species. Future development of artificial aphid diets should focus on matching the types and contents of nutritional elements with the digestive enzymes and gut microbes of aphids. It is necessary to develop specific artificial diets for targeted aphid populations rather than merely adopting successful formulations and experience with Myzus persicae or Acyrthosiphon pisum. In addition, automated and large-scale aphid rearing devices should be developed, and further research on population degradation during long-term aphid rearing is required to explore multifaceted solutions involving nutritional and environmental aspects. Full article

Precise regulation of the postharvest storage environment is critical for reducing losses and maintaining potato quality. Semi-underground storage facilities are widely used in major potato-producing regions of northern China; however, pronounced spatiotemporal heterogeneity in the internal temperature field often leads to localized quality deterioration. To enable accurate sensing and proactive prediction of temperature dynamics in such facilities, this study investigated a typical semi-underground potato storage cellar in Wuchuan County, Inner Mongolia. A high-density sensor network was deployed to collect temperature data, and the spatiotemporal variation patterns of the internal temperature field were systematically analyzed. The results indicate that, at the same vertical height, spatial temperature gradually increases from the entrance toward the interior of the cellar. Both the maximum and minimum temperatures in the entrance zone are lower than those in other regions, while the highest temperatures are observed near the rear wall. Based on the collected data, hierarchical clustering was employed to partition the internal temperature field into three spatiotemporal pattern clusters with significant differences. Key representative monitoring locations were then identified using the Spearman correlation coefficient. An AdaBoost-based prediction model was subsequently developed to estimate the temperatures at other test locations within each cluster using measurements from the representative points. The results demonstrate that the proposed model maintains high prediction accuracy while substantially reducing dependence on a dense sensor network. The overall MAE ranges from 0.075 to 0.373 °C, and the sensor reduction ratio reaches 87%. This approach provides a paradigm for low-cost intelligent monitoring and offers theoretical support and decision-making guidance for the smart regulation of potato storage environments. By optimizing the monitoring of potato storage environments, this study can reduce monitoring system costs and resource consumption, providing technical support for building a sustainable potato supply chain and delivering significant economic benefits in promoting the development of a resource-conserving potato industry. Full article

Insect farming for several purposes, which inscribes itself into circular economy, could become an alternative to traditional agriculture in Europe. Insects are a more sustainable and circular alternative source of protein and fat in food and feeds. The aim of this study is to identify legal barriers to the rearing of insects and marketing of insect-based products. The study focuses on the identification of such barriers to insect rearing and to the production of fertilizers from insect frass. The dogmatic legal method, as well as SWOT and PESTEL analyses, are employed in this research. The two latter methods are used to gain insight into the views held by the industry’s stakeholders. Subsequently, issues within the research field, such as the rearing of insects, their welfare, and the requirements imposed on the feeding of farmed insects, are discussed. Finally, solutions to the identified problems are suggested. The most important strengths of insect farming are its innovative edge and the creation of new products at the EU level. Weaknesses include technological and organizational challenges. Stakeholders attribute high importance to external circumstances, especially economic and social ones. As concluded from this study, the current laws are not optimal for insect farming; however, despite this situation, some changes to the law could facilitate the acquisition of feed for insects or the marketing of some insect-based products. The proposed legal changes aim at lifting the identified barriers to insect farming while still meeting safety requirements and supporting circular economy principles. Full article

This study examines the hydrodynamic performance and energy conversion mechanisms of a dual-float wave energy converter (WEC) to address the limitations of single-float WECs regarding energy capture efficiency and cost-effectiveness. A three-dimensional numerical wave tank is constructed utilizing computational fluid dynamics (CFDs) technology and STAR-CCM+ to simulate the dynamic response of the dual-float system under specific wave conditions characterized by a height of 0.1 m and a period of 1.5 s. The effects of a front-rear configuration with a quarter-wavelength spacing on the converter’s power output, turbofan rotational characteristics, and heave motion are systematically analyzed. The results indicate that the wave-facing float attains a consistent rotational speed of 4 rad/s, exhibiting significant fluctuations in heave displacement and velocity. Conversely, the downstream float exhibits diminished motion amplitude, a constant rotational velocity of 2.5 rad/s, and curtailed power generation attributable to wave diffraction and energy shielding from the wave-facing float. The mutual hydrodynamic interference between the floats influences the total energy conversion efficiency, as evidenced by the dual-float system’s array impact factor of 0.989. A parametric study covering multiple wave conditions and float spacing is supplemented to reveal the influence law of key parameters on system performance. This paper elucidates the fundamental mechanism of hydrodynamic coupling in dual-float arrays and offers a theoretical foundation and technical guidance for the optimal design and engineering application of arrayed WECs. Full article