Search Results (122)

Jujubes have a beautiful taste, and high nutritional and economic value. The planting area of dwarf and densely planted jujubes is large and shows an increasing trend; however, the mechanization level and efficiency of fresh jujube harvesting are low. For this reason, our research group conducted a study on mechanical harvesting technology for fresh jujubes. A pneumatic jujube harvester was designed. This harvester is composed of a self-regulating picking mechanism, a telescopic conveying pipe, a negative pressure generator, a cleaning mechanism, a double-chamber collection box, a single-door shell, a control assembly, a generator, a towing mobile chassis, etc. During the harvest, the fresh jujubes on the branches are picked under the combined effect of the flexible squeezing of the picking roller and the suction force of the negative pressure air flow. They then enter the cleaning mechanism through the telescopic conveying pipe. Under the combined effect of the upper and lower baffles of the cleaning mechanism and the negative-pressure air flow, the fresh jujubes are separated from impurities such as jujube leaves and branches. The clean fresh jujubes fall into the collection box. We considered the damage rate of fresh jujubes, impurity rate, leakage rate, and harvesting efficiency as the indexes, and the negative-pressure suction wind speed, picking roller rotational speed, and the inclination angle of the upper and lower baffles of the cleaning and selection machinery as the test factors, and carried out the harvesting test of fresh jujubes. The test results show that when the negative-pressure suction wind speed was 25 m/s, the picking roller rotational speed was 31 r/min, and the inclination angles of the upper and lower baffle plates for cleaning and selecting were −19° and 19.5°, respectively, the breakage rate of fresh jujube harvesting was 0.90%, the rate of impurity was 1.54%, the rate of leakage was 2.59%, and the efficiency of harvesting was 73.37 kg/h, realizing the high-efficiency and low-loss harvesting of fresh jujubes. This study provides a reference for the research and development of fresh jujube mechanical harvesting technology and equipment. Full article

Magnetorheological (MR) foams represent a class of smart materials with unique tunable viscoelastic properties when subjected to external magnetic fields. Combining porous structures with embedded magnetic particles, these materials address challenges such as leakage and sedimentation, typically encountered in conventional MR fluids while offering advantages like lightweight design, acoustic absorption, high energy harvesting capability, and tailored mechanical responses. Despite their potential, challenges such as non-uniform particle dispersion, limited durability under cyclic loads, and suboptimal magneto-mechanical coupling continue to hinder their broader adoption. This review systematically addresses these issues by evaluating the synthesis methods (ex situ vs. in situ), microstructural design strategies, and the role of magnetic particle alignment under varying curing conditions. Special attention is given to the influence of material composition—including matrix types, magnetic fillers, and additives—on the mechanical and magnetorheological behaviors. While the primary focus of this review is on MR foams, relevant studies on MR elastomers, which share fundamental principles, are also considered to provide a broader context. Recent advancements are also discussed, including the growing use of artificial intelligence (AI) to predict the rheological and magneto-mechanical behavior of MR materials, model complex device responses, and optimize material composition and processing conditions. AI applications in MR systems range from estimating shear stress, viscosity, and storage/loss moduli to analyzing nonlinear hysteresis, magnetostriction, and mixed-mode loading behavior. These data-driven approaches offer powerful new capabilities for material design and performance optimization, helping overcome long-standing limitations in conventional modeling techniques. Despite significant progress in MR foams, several challenges remain to be addressed, including achieving uniform particle dispersion, enhancing viscoelastic performance (storage modulus and MR effect), and improving durability under cyclic loading. Addressing these issues is essential for unlocking the full potential of MR foams in demanding applications where consistent performance, mechanical reliability, and long-term stability are crucial for safety, effectiveness, and operational longevity. By bridging experimental methods, theoretical modeling, and AI-driven design, this work identifies pathways toward enhancing the functionality and reliability of MR foams for applications in vibration damping, energy harvesting, biomedical devices, and soft robotics. Full article

Anastomotic leaks after colorectal resection are serious surgical complications. We have compared the integrity of two common colorectal anastomosis techniques, end-to-side (ES) and end-to-end (EE), to control specimens using a novel experimental setup that mimics anastomotic air leak tests, which are typically performed during surgeries. Freshly harvested porcine colonic sections from 23 F1 cross-species pigs were used. Pressure measurements and video imaging were used to monitor the ex vivo experiments on EE, ES, and Control specimens. Using EE (n = 16), ES (n = 12), and Control (n = 22) specimens, leak pressure was 282.6 ± 3.0 mm Hg for EE, 282.8 ± 2.6 mm Hg for ES, and 294.4 ± 12.1 for the Control. Time to leakage was 106.3 ± 28.1 s for EE, 263.9 ± 2127.0 s for ES, and 194.5 ± 90.2 s for the Control. We found that, while EE and ES have nearly identical leak pressures, ES was superior in terms of time to leakage and tissue expansion, which may explain why ES anastomoses have a lower clinical anastomotic leak rate. Two dependent variables representing stress and strain of colonic tissues were introduced. These variables showed ES was comparable to the Control. The experiments were simulated successfully using the finite element method (FEM). This research provides a reproducible ex vivo system with a corresponding FEM system to study the differences between anastomosis techniques and may help design anastomoses with lower leak rates and improve patient outcomes in colorectal surgeries. Full article

The increasing demand for sustainable and autonomous monitoring solutions in critical infrastructure has driven interest in Green Internet of Things (G-IoT) systems. This paper presents an analytical and experimental framework for designing energy-efficient, self-sustaining pipeline monitoring systems that leverage renewable energy harvesting and low-power operation techniques. We propose a hybrid approach combining solar energy harvesting with energy-saving strategies such as adaptive sensing, duty cycling, and distributed computing to extend the lifetime of IoT nodes without human intervention. Using real-world irradiance data and energy profiling from a prototype testbed, we analyze the impact of solar panel sizing, energy storage capacity, energy-saving strategies, and energy leakage on the energy balance of IoT nodes. The simulation results show that, with optimal dimensioning, harvested solar energy can sustain pipeline monitoring operations over multi-year periods, even under variable environmental conditions. We investigated the influence of design parameters such as duty cycling, solar panel area, the capacity of the energy storage system, and the energy leakage coefficient on energy performance metrics such as the autonomy or lifetime of the node (time required to drain all the stored energy), which is an important design object. This framework provides practical design insights for the scalable deployment of G-IoT systems in energy-constrained outdoor environments. Full article

The use of non-wood forest products plays a significant role in sustainable development, especially in the context of regional development. One of the most important and promising raw materials is birch sap, which in European conditions is obtained mainly from silver birch (Betula pendula Roth). Research on the utility value of birch sap and the influence of a number of factors on its efficiency and quality has been carried out in many research centers, but so far, there are not many studies on the variability of such parameters as a function of time, taking into account the entire period of sap leakage. This research was carried out in birch stands of approximately 80 years in three forest site types: mixed coniferous forest, mixed broadleaved forest, and broadleaved forest. In each site, nine sample trees were selected using Hartig’s method. The daily and all-season sap yield obtained from individual trees was statistically characterized. The relationship between birch sap yield and select quantitative (tree height, absolute and relative crown length, and slenderness) and qualitative (forest site type, tree thickness class, and sap harvesting period) variables was examined. For the first time in the literature on the subject, there is a proposal to distinguish the phases of obtaining birch sap, which may bring new knowledge, both in relation to daily productivity and the quality of the sap. As a result, the smallest amount of sap was found in the initial leak phase, a slightly higher amount was found in the final phase, and the largest amount was found in the main phase. Regarding the forest site type and the interaction between the collection phase and forest site type, no statistically significant relationship with the average amount of obtained sap was found. Full article

In recent years, there has been growing interest in the use of native ground-grown perennials in floral compositions as cut greenery. The easily available plant materials that can replace some exotic species include Hosta leaves and the leafy shoots of Polygonatum multiflorum. Their vase life should be at least as long as that of the flowers, with which they are combined. In order to prolong the vase life of cut greenery, the conditioning of cut plant material in solutions of plant hormones (GA3 and BA) and commercial conditioning substances (8HQC and Chrysal Clear 2) is most commonly performed. The aim of this study was to evaluate the effect of different conditioning solutions on vase life and parameters indicating the progression of the senescence of plant materials. Cut Hosta leaves and leafy shoots of Polygonatum multiflorum were conditioned immediately after cutting for 24 h in aqueous solutions of benzyladenine (BA) and gibberellic acid (GA₃), 8HQC standard medium with the addition of 2% sucrose and 1% Chrysal Clear 2 solution. The post-harvest storage and physiological senescence parameters of the plant materials were analyzed using the following indicators: the vase life, the relative water content (RWC), electrolyte leakage (E_L), and thiobarbituric acid reactive substance (TBARS) and pigment contents (chlorophyll a, chlorophyll b, carotenoids, and anthocyanins). Conditioning Hosta leaves in a BA solution at 100 mg L⁻¹ immediately after cutting more than doubles their post-harvest vase life. The longevity of P. multiflorum shoots can be effectively extended by storage in a BA solution of 400 mg L⁻¹, for 24 h. Both the plant materials responded to the progressive aging process with the disruption of water management, a reduction in cytoplasmic membrane integrity, and a decrease in the plant pigment content. Tissue water retention in the Hosta leaves was most favorably affected by conditioning in the GA₃ solution at a concentration of 400 mg L⁻¹. The P. multiflorum shoots responded with tissue water retention to conditioning in 1% Chrysal Clear 2 solution. The conditioning of Hosta leaves in BA solution at 400 mg L⁻¹ stabilized the cytoplasmic membranes and inhibited E_L most effectively. In P. multiflorum, the lowest E_L level was found as an effect of conditioning the shoots in GA₃ solution at 200 mg L⁻¹. The degradation of assimilation pigments was prevented by conditioning the Hosta leaves in GA₃ solution at 200 mg L⁻¹ and the P. multiflorum leafy shoots in GA₃ solution, regardless of the concentration used. Although the prolongation of the vase life of the cut leaves and the shoots by up to 30 days was achieved, along with an improvement in the appearance of the plant materials, it was not possible to identify a single conditioner that had a positive effect on all the parameters studied. Full article

Sweet basil (Ocimum basilicum L.) is highly susceptible to chilling injury (CI), resulting in the development of CI symptoms during cold storage that reduce postharvest quality and shelf life. This study evaluated whether silicon (Si) and abscisic acid (ABA) applications can mitigate these symptoms. In Trial 1, basil plants had a Si solution (189 mg/L Si from potassium silicate) or deionised water (control) applied during cultivation via rootzone irrigation or foliar spray. Some plants were also foliar sprayed with ABA (1000 mg/L) before harvest. In Trial 2, wollastonite was added to the growing media (0, 1, 2, 3, 4, 5 mL/L) as the Si source. Applying the Si solution using either method reduced leaf necrosis, fresh weight loss, and electrolyte leakage, extending shelf life to at least 14 days. There were also no negative impacts on plant performance during cultivation (chlorophyll content, shoot height, and canopy width). The ABA solution, alone or in combination with Si solution, reduced symptoms but less effectively, extending shelf life up to 8 days. Wollastonite had no positive effects. These findings suggest that Si solution applications are a promising strategy to alleviate CI during postharvest cold storage of basil at 3.5 °C. Full article

The interest in forests from a climate and biodiversity perspective is increasing. Several scientific scenarios and political narratives suggest that reduced timber harvest may facilitate these perspectives. However, reducing timber harvest in one location might result in an increased harvest elsewhere. A harvest leakage might occur. This study estimates the magnitude of leakage due to potential reductions in timber harvests in Sweden. The leakage is calculated using an empirical estimation model based on market responses. The results indicate that 24–77 percent of the reduced harvest will be offset by an opposing change in other countries, depending on timber assortment and time horizon. Thus, the magnitude of the leakage is case specific, but, in all cases, sizeable. Subsequently, the expected climate benefits of policies may be severely reduced if the leakage is left unaddressed in the policy design. Full article

The future Internet of Things (IoT) will consist of energy harvesting devices and Unmanned Aerial Vehicles (UAVs) to support applications in remote areas. However, as UAVs communicate with IoT devices using broadcast channels, information leakage emerges as a critical security threat. This paper considers the problem of maximizing the minimum secrecy rate in an energy harvesting IoT network supported by two UAVs, where one acts as a server to collect data from devices, and the other is an eavesdropper to intercept data transmission. It presents a novel Mixed-Integer Nonlinear Program (MINLP), which we then linearize into a Mixed-Integer Linear Program (MILP) problem. It also proposes a heuristic solution called Fly Nearest Location (FNL). Both solutions determine (i) the UAV server’s flight routing, flight time, and computation time, as well as (ii) the energy usage and operation mode of IoT devices. Our results show that FNL achieves on average 78.15% of MILP’s performance. Full article

Crop failure is defined as crop production that is significantly lower than anticipated, resulting from plants that are harmed, diseased, destroyed, or influenced by climatic circumstances. With the rise in global food security concern, the earliest detection of crop diseases has proven to be pivotal in agriculture industries to address the needs of the global food crisis and on-farm data protection, which can be met with a privacy-preserving deep learning model. However, deep learning seems to be a largely complex black box to interpret, necessitating a prerequisite for the groundwork of the model’s interpretability. Considering this, the aim of this study was to follow up on the establishment of a robust deep learning custom model named CropsDisNet, evaluated on a large-scale dataset named “New Bangladeshi Crop Disease Dataset (corn, potato and wheat)”, which contains a total of 8946 images. The integration of a differential privacy algorithm into our CropsDisNet model could establish the benefits of automated crop disease classification without compromising on-farm data privacy by reducing training data leakage. To classify corn, potato, and wheat leaf diseases, we used three representative CNN models for image classification (VGG16, Inception Resnet V2, Inception V3) along with our custom model, and the classification accuracy for these three different crops varied from 92.09% to 98.29%. In addition, demonstration of the model’s interpretability gave us insight into our model’s decision making and classification results, which can allow farmers to understand and take appropriate precautions in the event of early widespread harvest failure and food crises. Full article

Energy harvesting systems are becoming increasingly vital for sustainable power supply in Internet of Things (IoT) applications. These systems involve capturing and converting energy from environmental sources into electrical power. This paper presents a high-efficiency 5.8 GHz energy harvester for powering such devices, designed in a 65 nm pure CMOS process. The proposed design utilizes a metal-oxide-semiconductor field-effect-transistor-based Dickson charge pump energy harvester for high-frequency energy conversion. Simulation results are presented and discussed on the post-layout verified and extracted circuits with matching implemented to emulate the real-world testing scenarios. The design addresses challenges specific to high-frequency operation, including parasitic capacitances, frequency-dependent leakage currents, and impedance mismatches, ensuring optimal performance at higher frequencies. The evaluation focuses on key metrics such as output voltage and power conversion efficiency (PCE), with the harvester demonstrating an output voltage of 2.88 V and an efficiency of 82.94%. Full article

Green energy conversion and storage materials have become a focal point of research in recent times, especially in energy-consuming buildings. Phase change materials (PCMs) have gained more and more attention not only for energy storage but also in composites for solar energy conversion. This research investigates a sustainable method for converting orange biomass waste (OBW) into advanced porous carbon aerogel (PCA) composites, designed for solar-thermal energy harvesting and storage in building applications. Using potato starch as a binder, the research develops a process for producing a uniform and lightweight carbon matrix that could be scalable. The best results were found for PCA obtained with 2.5% starch, where the lowest mass loss (8.2, 0.5, 11.2% pt) was observed during the leakage test. This study highlights the suitability of OBW-derived aerogels as effective matrices for PCM impregnation and shape stabilization, indicating their future potential in solar-thermal energy conversion and storage and potentially lowering energy consumption in buildings. By repurposing agricultural waste, this work contributes to sustainable material development and advances the application of renewable energy technologies. Full article

Free-standing ferroelectric films have emerged as a transformative technology in the field of flexible electronics, offering unique properties that enable a wide range of applications, including sensors, actuators, and energy harvesting devices. This review paper explores recent advancements in the fabrication, characterization, and application of free-standing ferroelectric films, highlighting innovative techniques such as multilayer structures and van der Waals epitaxy that enhance their performance while maintaining mechanical flexibility. We discuss the critical role of these films in next-generation devices, emphasizing their potential for integration into multifunctional systems that combine energy harvesting and sensing capabilities. Additionally, we address challenges related to leakage currents, polarization stability, and scalability that must be overcome to facilitate commercialization. By synthesizing current research findings and identifying future directions, this paper aims to provide a comprehensive overview of the state-of-the-art in free-standing ferroelectric films and their impact on the development of sustainable and efficient flexible electronic technologies. Full article

China’s carrot planting area and total output rank first in the world, but China’s mechanized carrot harvesting level is relatively backward. There are many problems in the existing machine operation process, among which the problems of a high leakage rate and high damage rate are the main difficulties faced. In order to study this problem, a test platform composed of clamping and pulling devices and conveying devices is designed, and it can complete the experiments of clamping, pulling and conveying carrot plants and collecting carrot stalks at one time. During the test, the clamping speed was divided into four test levels: 0.40 m/s (T1), 0.85 m/s (T2), 1.30 m/s (T3), and control test (CK), and each test level was carried out three times at different forward speeds. Finally, the leakage rate and damage rate were statistically analyzed. The results show that the average damage rate of Xiahong2 is 6.13%, 3.53%, and 9.36% and that of Sanhong is 6.22%, 3.76%, and 9.88% under the clamping and conveying speeds of T1, T2, and T3 in two years. The average carrot missed-pulling rate of two consecutive years corresponding to two carrot varieties, Xiaohong2 and Sanhong, was 3.68% and 4.14%, respectively. The carrot missed-pulling rate of CK in the control group of two carrot varieties, Xiaohong2 and Sanhong, was high and stable at 96.2% to 97.5%. At the same time, T1, T2, and T3 had similar overall trends of high carrot leakage rates for two carrot varieties at different clamping and conveying speeds. This control experiment also proves that the experimental arrangement is scientific and accurate. The average carrot leakage rate of T1, T2, and T3 for Xiahong2 is 3.91%, 3.42%, and 6.22%, and that of T1, T2, and T3 for Sanhong is 4.06%. The research results can provide a theoretical basis and reference for the optimization and improvement of carrot clamping and conveying devices, and this research can provide a reference for how to reduce the harvest loss of carrot combine harvesters in China. Full article

Indian jujube fruit is prone to perishing, resulting in a shorter shelf life after harvest. Kadozan is a liquid chitosan formulation that has a significant effect on fruit preservation. In order to explore its efficacy, the quality, and storability indicators of Indian jujube fruit were evaluated during storage at 15 ± 1 °C for 18 days. Results showed that Kadozan-treated fruit exhibited lower respiration rate, relative electrolyte leakage rate, weight loss, and decay index, along with higher firmness and commercially acceptable rate. Furthermore, Kadozan-treated fruit showed higher vitamin C, total sugar, titratable acid, total soluble solids, chlorophyll, and carotenoid contents, L* and h° values, but lower a* and b* values. Principal component analysis and comprehensive score revealed that Kadozan treatment helped preserve the appearance and nutritional qualities of Indian jujube fruit. The best effect was seen with 1:600 Kadozan among three concentrations (1:300, 1:600, 1:900). It was discovered that the commercially acceptable rate of 1:600 Kadozan-treated fruit was 37.5% higher than control fruit while the decay index was 30.5% lower than control fruit at 18 days. Therefore, Kadozan treatment has great substantial implications for the preservation of Indian jujube fruit, providing practical guidance for reducing its postharvest losses. Full article