Search Results (20)

To advance the construction of intelligent mining, electro-hydraulic digital control technology has emerged as a critical direction for the digital transformation of mining machinery. This study proposes a digital control scheme based on the pressure state of the system and the operating state of the actuator. The scheme utilises a novel convergence rate sliding film position control method to regulate the system pressure in real time by controlling the pilot valve, which is driven by a permanent magnet synchronous motor (PMSM). Moreover, a prototype of an incremental digital pressure control valve was developed for high-pressure, high water-based working conditions. A simulation model of the valve was established using AMESim/Simulink, and dynamic characteristics under various operating conditions were analyzed. The relative error between simulated and experimental pressure results remained within ±4.7%. Finally, a multi-parameter optimization was conducted using a genetic algorithm. The results demonstrate that the optimized digital pressure control valve achieved a stabilized inlet pressure within 44.8 ms, with a pressure overshoot of 4.1% and a response time of 20.1 ms, exhibiting excellent real-time dynamic pressure regulation capabilities. This study provides a theoretical foundation and practical reference for comprehensive research on pressure control in underground emulsion pump stations. Full article

Polyethylene microplastics (PE MPs) pose a severe threat to aquatic ecosystems and human health, demanding urgent, sustainable remediation strategies. While the electro-Fenton process is widely used for treating refractory pollutants in wastewater, its standalone application remains inadequate for PE MPs due to their stable chemical structure and complex molecular chains. This study introduces a green and sustainable magnetite-activated persulfate electro-Fenton (Mt-PS-EF) system designed to address these limitations while aligning with circular-economy principles. By synergizing Fe₃O₄ catalysis, persulfate activation, and electrochemical processes, the Mt-PS-EF system achieves efficient PE MP degradation through hydroxyl (·OH) and sulfate (SO₄·⁻) radical-driven oxidation. Under optimized conditions (60 mg/L PE, 40 mM persulfate, 150 mg Fe₃O₄, 20 h treatment), a 90.6% degradation rate was attained, with PE MPs undergoing chain scission, surface erosion, and release of low-molecular-weight organics. Crucially, the magnetic property of magnetite facilitated the recovery and reuse of the catalyst, significantly reducing material costs and minimizing waste generation. By integrating catalytic efficiency with resource recovery, this work advances scalable, eco-friendly solutions for microplastic pollution mitigation, directly contributing to UN Sustainable Development Goals (SDGs) 6 (Clean Water) and 14 (Life Below Water). The findings highlight the potential of hybrid electro-Fenton technologies in achieving sustainable wastewater treatment and plastic waste management. Full article

In this paper, an EML (electro-magnetic log) integrated navigation algorithm based on the HMM (hidden Markov model) and CNLKF (cross-noise linear Kalman filter) is proposed, which is suitable for SINS (strapdown inertial navigation system)/EML/GNSS (global navigation satellite system) integrated navigation systems for small or medium-sized AUV (autonomous underwater vehicle). The algorithm employs the following five techniques: ① the HMM-based pre-processing algorithm of EML data; ② the CNLKF-based fusion algorithm of SINS/EML information; ③ the MALKF (modified adaptive linear Kalman filter)-based algorithm of GNSS-based calibration; ④ the estimation algorithm of the current speed based on output from MALKF and GNSS; ⑤ the feedback correction of LKF (linear Kalman filter). The principle analysis of the algorithm, the modeling process, and the flow chart of the algorithm are given in this paper. The sea trial of a small-sized AUV shows that the endpoint positioning error of the proposed/traditional algorithm by this paper is 20.5 m/712.1 m. The speed of the water current could be relatively accurately estimated by the proposed algorithm. Therefore, the algorithm has the advantages of high accuracy, strong anti-interference ability (it can effectively shield the outliers of EML and GNSS), strong adaptability to complex environments, and high engineering practicality. In addition, compared with the traditional DVL (Doppler velocity log), EML has the advantages of great concealment, low cost, light weight, small size, and low power consumption. Full article

In this article, the authors developed a novel method for the moisture mapping of the soil surface of agrophytocenosis using a neural network based on synchronized radar and multispectral optoelectronic data from Sentinel-1,2. The significance of this research lies in its potential to enhance precision farming practices, which are increasingly vital in addressing global agricultural challenges such as water scarcity and the need for sustainable resource management. To verify the developed method, data from two experimental plots were utilized. These plots were located on irrigated soybean crops, with the first plot situated on the right bank (plot No. 1) and the second on the left bank (plot No. 2) of the lower Volga River. Two experimental soil moisture geodatasets were created through measurements and geo-referencing points using the gravimetric method (for plot No. 1) and the proximal sensing method (for plot No. 2) employing the Soil Moisture Sensor ML3-KIT (THETAKIT, Delta). The soil moisture retrieval algorithm was based on the use of a neural network to predict the reflection coefficient of an electro-magnetic wave from the soil surface, followed by inversion into soil moisture using a dielectric model that takes into account the soil texture. The input parameter of the neural network was the ratio of the microwave radar vegetation index (calculated based on Sentinel-1 data) to the index (calculated based on the data of multispectral optoelectronic channels 8 and 11 of Sentinel-2). The retrieved soil moisture values were compared with in situ measurements, showing a determination coefficient of 0.44–0.65 and a standard deviation of 2.4–4.2% for plot No. 1 and similar metrics for plot No. 2. The conducted research laid the groundwork for developing a new technology for remote sensing of soil moisture content in agrophytocenosis, serving as a crucial component of precision farming systems and agroecology. The integration of this technology promotes sustainable agricultural practices by minimizing water consumption while maximizing crop productivity. This aligns with broader environmental goals of conserving natural resources and reducing agricultural runoff. On a larger scale, data derived from such studies can inform policy decisions related to water resource management, guiding regulations that promote efficient water use in agriculture. Full article

While the advantageous effects of using magnetic and electromagnetic treatment (ET) of brackish and saline waters on soil salinity reduction in the root zone were largely reported, more studies are needed to answer questions about the soil salt leaching efficiency and the effect of the duration of the exposure to ET. For this aim, pot experiments were conducted using an Aqua-4D^R physical water treatment device. The first experiment included two trials. The first trial considered five concentrations: C0:1.0; C1:4.5; C2:9; C3:13.5; and C4:18 dS m⁻¹. The results revealed that the volume and the salt concentrations of the drained waters were significantly higher under irrigation with ET saline waters than those provided by untreated waters. The drained fraction of water varied from 20 to 26% under irrigation with untreated water and increased from 33 to 56% under irrigation with electro-magnetized water, indicating an improvement in the salt leaching. The second trial was carried out with different irrigation doses. The results showed that the higher the dose, the more obvious and significant the ET effect. The different treatment durations of water exposure revealed that the volume and salinity of drained water significantly increase as the ET duration increases. An increase in the ET duration also induces an increase in the soil water content of around 2.5%. Based on the experimental findings, we may conclude that the ET of saline water can reduce the adverse effect of salinity on the top soil, but these leached salts are carried away in depth and there is no concentration limit of water to the effect of the ET. Full article

The reciprocating plate column is a kind of column with the plates driven by a geared motor, and it has advantages in regard to efficiency compared to traditional columns in the extraction process, however, it comes with an increase in energy consumption. A new type of reciprocating plate column driven by electro-permanent magnet technology (EPM) is proposed in this paper to obtain a better performance with lower energy consumption. The feasibility and performance of the proposed column is studied by numerical simulation and experiments with a kerosene–water system. The electro-permanent magnet chuck could provide a maximum amplitude of 12 mm in this study. Kerosene was used as the dispersed phase, and deionized water was used as the continuous phase, in a laboratory-scale 35 mm diameter reciprocating plate column driven by EPM. Hydrodynamic performance experiments were carried out with different flowrates of both phases and reciprocating frequencies. The experimental results show that the electro-permanent magnet chuck, which serves as the driving device of the reciprocating plate column, plays the role of adding energy and increasing the droplet breakage. In addition, the energy consumption of the reciprocating plate column with traditional geared motor and electro-permanent magnet chuck is calculated respectively. Compared with the traditional geared motor, the energy saving of the electro-permanent magnet chuck is as high as 98.55%. Full article

The Controlled-Source ElectroMagnetic (CSEM) method provides crucial information about reservoir fluids and their spatial distribution. Carbon dioxide (CO₂) storage, enhanced oil recovery (EOR), geothermal exploration, and lithium exploration are ideal applications for the CSEM method. The versatility of CSEM permits its customization to specific reservoir objectives by selecting the appropriate components of a multi-component system. To effectively tailor the CSEM approach, it is essential to determine whether the primary target reservoir is resistive or conductive. This task is relatively straightforward in CO₂ monitoring, where the injected fluid is resistive. However, for scenarios involving brine-saturated (water-wet) or oil-wet (carbon capture, utilization, and storage—CCUS) reservoirs, consideration must also be given to conductive reservoir components. The optimization of data acquisition before the survey involves analyzing target parameters and the sensitivity of multi-component CSEM. This optimization process typically includes on-site noise measurements and 3D anisotropic modeling. Based on our experience, subsequent surveys tend to proceed smoothly, yielding robust measurements that align with scientific objectives. Other critical aspects to be considered are using magnetotelluric (MT) measurements to define the overall background resistivities and integrating real-time quality assurance during data acquisition with 3D modeling. This integration allows the fine tuning of acquisition parameters such as acquisition time and necessary repeats. As a result, data can be examined in real-time to assess subsurface information content while the acquisition is ongoing. Consequently, high-quality data sets are usually obtained for subsequent processing and initial interpretation with minimal user intervention. The implementation of sensitivity analysis during the inversion process plays a pivotal role in ensuring that the acquired data accurately respond to the target reservoirs’ expected depth range. To elucidate these concepts, we present an illustrative example from a CO₂ storage site in North Dakota, USA, wherein the long-offset transient electromagnetic method (LOTEM), a variation of the CSEM method, and the MT method were utilized. This example showcases how surface measurements attain appropriately upscaled log-scale sensitivity. Furthermore, the sensitivity of the CSEM and MT methods was examined in other case histories, where the target reservoirs exhibited conductive properties, such as those encountered in enhanced oil recovery (EOR), geothermal, and lithium exploration applications. The same equipment specifications were utilized for CSEM and MT surveys across all case studies. Full article

Global climatic change intensifies the water crisis, particularly in arid and semi-arid regions. In this regard, the provision of enough water for irrigation is a serious dilemma because the agricultural sector consumes the largest amount of water (70% withdrawal and 90% consumption). In this review, we have summarized recent innovations that have emerged as unconventional techniques to supply adequate water for irrigation purposes. We present the principles and basics of seven approaches: the Sahara Forest Project (SFP), water extraction from the air (WEA), aquifer recharge, the treatment of marginal water using a magnetic field, desalination and wastewater treatment (DWT), electro-agric technology (E-AT), and the Toshka Project. The SFP is currently being utilized in Aqaba, Jordan, and DWT is considered a common practice worldwide, whereas some of these innovations are still under investigation to ensure their feasibility for large-scale applications, such as E-AT. The Toshka Project is considered a wonderful idea that utilizes the water stored behind the High Dam in Lake Nasser, Egypt. Several approaches have been adopted to reduce the amount of water being used for irrigation, as the current amount of freshwater is insufficient for the requirements of increased agricultural consumption, particularly in hot, arid, and semi-arid regions. Full article

In the context of global warming, agriculture faces severe challenges such as water scarcity and soil erosion. Key to achieving soil sustainability is the choice of farming practices, the consequences of which are generally site-specific. In this study, the ability of Electrical Resistivity Tomography (ERT) and Electro Magnetic Induction (EMI) methods were assessed for monitoring the effects of conventional (CONV) and conservation (CONS) agricultural practices. The aim is to highlight differences in soil water distribution caused by both short- and long-term effects of the two different practices. Results demonstrated that both ERT and EMI provided sufficient information to distinguish between the effects of CONV and CONS, while traditional direct measurements, being punctual techniques, lacked sufficient spatial resolution. The ERT transects showed that the soil was much more homogeneous as a result of CONS practices, resulting in a higher sensitivity to changes in the water content. Conversely, due to the heterogeneous soil structure under CONV, water distribution was more irregular and difficult to predict. Similar patterns were also observed with the EMI surveys, with a strong link to spatial variability. Finally, we conclude that for CONV soil, the accessible water for the plant is clearly controlled by the soil heterogeneities rather than by the forcing atmospheric conditions. This study is a first step towards paving the way for more refined hydrology models to identify which soil parameters are key to controlling spatial and temporal changes in soil water content. Full article

Synthesis of polyaniline in the presence of fullerene nanotubes (nanocarbons) in water was carried out with oxidative polymerization. The surface of the sample showed metallic emerald green color in bulk like the brilliance of encrusted gemstones. The composite showed unique magnetic behavior, such as microwave power-dependent magnetic resonance as magnetic spin behavior and macroscopic paramagnetism with a maximum χ value at room temperature evaluated with superconductor interference device. Surface structure of the composite was observed with optical microscopy, circular polarized differential interference contrast optical microscopy, scanning electron microscopy, and electron probe micro analyzer. Polymer blends consisting of polyaniline, nano-carbons, and hydroxypropylcellulose or acryl resin with both conducting polymer and carbon characters were prepared, which can be applied for electrical conducting plastics. The combination of conducting polymer and nano-carbon materials can produce new electro-magneto-active soft materials by forming a composite. This paper reports evaluation of magnetic properties as a new point of nanocarbon and conducting polymer composite. Full article

It is known that poorly performed fertigation directly impacts on tomato production and biometric components. In addition, consumers are also affected by interrelated characteristics that interfere with the acceptability of the fruit, such as the physicochemical parameters and nutrients in the fruit. Thus, eco-friendly technologies, such as irrigation with ultra-low frequency electromagnetic treated-water, which attenuates the inadequate management of fertigation, are essential to improve marketable fruit yields. Thus, the objective of the present work was to investigate the impact of treated water with very low-frequency electromagnetic resonance fields in physical, chemical and nutritional parameters at different nutrient solution strengths in tomato fruits. In this study, experiments were carried out in randomized blocks and five doses of fertigation were used (1.5; 2.5; 4.0; 5.5; and 7.0 dS m⁻¹), employing two types of water: electromagnetically treated and untreated. It can be seen that the fertigation affected some parameters, mainly the number of fruits with blossom-end rot, fruit size, and weight. Variance analysis (ANOVA) was performed with the subsequent use of the Tukey test. In all statistical tests, a confidence level of 95% was considered. The soluble solids content increased by 28% as a function of the fertigation doses. The electromagnetically treated water reduced the number of fruits with blossom-end rot by 35% (p < 0.05). Overall, electromagnetic water improved the physicochemical quality parameters and the nutritional status of tomato fruits. Thus, this study demonstrated that green technology could leverage tomato fruit production and quality. Full article

In this work, a novel application of Active Magnetic Bearing (AMB) is proposed to integrate AMB in the Magnetically Coupled Thruster (MCT) assembly for underwater application. In this study, a 2-Degree-Of-Freedom (DOF) AMB is developed and investigated for the MCT of an Unmanned Underwater Vehicle (UUV). The paper presents the detailed electro-mechanical modeling of the in-house developed AMB system. The intractable problem of rotor suspension and rotation with opposing pairs of electromagnets is considered. A Linear Quadratic Gaussian (LQG) controller is designed and analyzed in the frequency domain for the stabilization of the open-loop unstable AMB for MCT. The performance specifications of the controller, such as reference tracking and disturbance rejection are achieved and evaluated through real-time implementation of the controller. The compensator also performed reasonably well during the dynamic operations, i.e., when the rotor-propeller assembly was spun at 1500 rpm. This rotor speed is needed to generate a thrust of 40–45 N and up to 1 m/s forward velocity, which is necessary to propel the UUV under consideration. By deploying AMB in MCT assembly, it is anticipated that problems associated with the conventional directly coupled thruster operating in harsh underwater environment, such as water ingress into electronics compartment, rusting, lubrication, and vibrations would be eliminated. Full article

To study the damage and destruction behavior of small coal pillars in coal mine roadway driving along gobs under long-term in-situ stress and multiple engineering disturbances, an unconfined compression experiment under a discontinuous cyclic load was designed, with the holding time as a variable. An electro-hydraulic servo rock testing machine was used to impose a discontinuous cyclic load on the coal sample and perform a final uniaxial compressive strength test. The changes in pore number and diameter in the coal under stress were monitored by nuclear magnetic resonance analysis. An increase in holding time in the discontinuous cyclic loading resulted in a significant increase in the number and diameter of pores in the coal sample; the coal porosity continued to increase, and the proportion of pores in the coal changed. The proportion of micropores decreased gradually, whereas the proportion of mesopores and macropores (cracks) increased. The degree of internal specimen damage increased with an increase of holding time, which resulted in a gradual decrease in final uniaxial compressive strength. Therefore, under the action of a long-term stress, to improve the bearing capacity of the coal pillar while avoiding gas and water influx into the working face in the goaf, the coal pillar should be reinforced with multi-layer and multi-grain grouting. Full article

Constructing micro-sized machines always involves the problem of how to bring the energy (electric, magnetic, light, electro wetting, vibrational, etc.) source to the device to produce mechanical movements. The paper presents a rotational micro-sized motor (the diameter of the rotor is 350 µm) driven by low frequency (200–700 Hz) circular vibrations, made by two piezoelectric actuators, through the medium of a water droplet with diameter of 1 mm (volume 3.6 µL). The theoretical model presents how to produce the circular streaming (rotation) of the liquid around an infinitely long pillar with micro-sized diameter. The practical application has been focused to make a time-stable circular stream of the medium around the finite long vibrated pillar with diameter of 80 µm in the presence of disturbances produced by the vibrated plate where the pillar is placed. Only the time-stable circular stream in the water droplet around the pillar produces enough energy to rotate the micro-sized rotor. The rotational speed of the rotor is controlled in both directions from −20 rad/s to +26 rad/s. 3D printed mechanical amplifiers of vibrations, driven by piezoelectric actuators, amplify the amplitude of the piezoelectric actuator up to 20 µm in the frequency region of 200 to 700 Hz. Full article

Although many studies in the literature illustrate the numerous devices and methodologies nowadays existing for assessing the spatial variability within agricultural fields, and indicate the potential for variable-rate irrigation (VRI) in vineyards, only very few works deal with the implementation of VRI systems to manage such heterogeneity, and these studies are usually conducted in experimental fields for research aims. In this study, a VR drip irrigation system was designed for a 1-ha productive vineyard in Northern Italy and managed during the agricultural season 2018, to demonstrate feasibility and effectiveness of a water supply differentiated according to the spatial variability detected in field. Electrical resistivity maps obtained by means of an electro-magnetic induction sensor were used to detect four homogeneous zones with similar soil properties. In each zone, a soil profile was opened, and soil samples were taken and analyzed in laboratory. Two irrigation management zones (MZs) were identified by grouping homogeneous zones on the basis of their hydrological properties, and an irrigation prescription map was built consistently with the total available water (TAW) content in the root zone of the two MZs. The designed drip irrigation system consisted of three independent sectors: the first two supplied water to the two MZs, while the third sector (reference sector) was managed following the farmer’s habits. During the season, irrigation in the first two sectors was fine-tuned using information provided by soil moisture probes installed in each sector. Results showed a reduction of water use by 18% compared to the ‘reference’ sector without losses in yield and product quality, and a grape’s maturation more homogeneous in time. Full article