The problems of large deformations, failures, and fractures that agricultural tillage tools may encounter during the cultivation process has long been a concern in the field of agricultural machinery design and manufacturing. It is important to establish a more accurate numerical model to effectively predict tools’ plastic deformation failures and ductile fracture failures. This research develops a numerical model for predicting the plastic deformation failure and ductile fracture failure of agricultural tillage tools using the smoothed particle hydrodynamics (SPH) method and the Johnson−Cook constitutive model. The model uses the Drucker−Prager criterion to describe the elastic−plastic constitutive behavior of the soil, the von Mises criterion to describe the Johnson−Cook constitutive model of the tool, and the coupling condition with the Lennard-Jones repulsive force to describe the interaction between the tool and soil. The numerical results show that the proposed model can effectiv... [more]

The treatment of chabazite (CHA), a natural zeolite, with the alkaline hydrothermal method to improve its ion-exchange capacity is a widely adopted route by environmental scientists for the purpose of better ammonium (NH4+) removal from wastewater. This work addresses a noteworthy trend in environmental science, where researchers, impressed by the increased ion-exchange capacity achieved through alkaline hydrothermal treatment, often bypass the thorough material characterization of treated CHA. The prevalent misconception attributes the improved features solely to the parent zeolitic framework, neglecting the fact that corrosive treatments like this can induce significant alterations in the framework and those must be identified with correct nomenclature. In this work, alkaline-mediated hydrothermally treated CHA has been characterized through X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), solid-state magic-angle spinning nuclear magnetic resonance (MAS... [more]

Currently, the focus of integrated energy system scheduling research is the multi-objective’s optimized operational strategies that take into account the economic benefits, carbon emissions, and new energy consumption rates of such systems. The integration of electric trucks with battery charging and swapping capabilities, along with their corresponding battery swapping stations, into an integrated energy system can not only optimize system operation, but also reduce investment costs associated with building energy storage equipment. This study first constructs an operational model for the electric trucks, as well as an electric truck battery swapping station, of the flexible charging and discharging; then, an optimized scheduling model of an integrated energy system is proposed, including an electric truck battery swapping station and using stepped carbon trading. On the basis of meeting the charging and battery swapping needs of electric trucks and coordinating the system’s electrica... [more]

Alpha particle-emitting radiopharmaceuticals are in high demand for use in targeted alpha therapy. Ac-225 is currently produced using Th-229, but its annual production remains low, approximately 63 GBq. Previously, we produced a large amount of Ac-225 via the (n,2n) reaction in fast reactors; however, it required repetitive irradiation. In this work, we investigated a method to produce Th-229 via the (3n,x) reaction through long-term irradiation using neutrons from Pressurized Water Reactors. As target nuclides, Ra-226, which is commonly used for Ac-225 production, and Th-230, which is not widely used but is abundant, were selected. The evaluation was conducted under mixed conditions of Th-230 and Th-232. Ra-226 and Th-230 produce Th-229 (T1/2 = 7920 years) after long-term neutron irradiation. Th-229, which has a long half-life, the α-decays to produce Ra-225, and the β-decays of Ra-225 to produce Ac-225. These processes are semi-permanent owing to the long half-life of Th-229. Further... [more]

Considering energy conversion efficiency, pollution emissions, and economic benefits, combining biomass with fossil fuels in power generation facilities is a viable approach to address prevailing energy deficits and environmental challenges. This research aimed to investigate the thermodynamic and exergoeconomic performance of a novel power and cooling cogeneration system based on a natural gas−biomass dual fuel gas turbine (DFGT). In this system, a steam Rankine cycle (SRC), a single-effect absorption chiller (SEAC), and an organic Rankine cycle (ORC) are employed as bottoming cycles for the waste heat cascade utilization of the DFGT. The effects of main operating parameters on the performance criteria are examined, and multi-objective optimization is accomplished with a genetic algorithm using exergy efficiency and the sum unit cost of the product (SUCP) as the objective functions. The results demonstrate the higher energy utilization efficiency of the proposed system with the therma... [more]

FeNi films were prepared using the DC magnetron sputtering technique with an oblique deposition arrangement. Multilayers with different orientations of the magnetic anisotropy axes were obtained thanks to a rotary sample holder inside the vacuum chamber. Magnetic properties were studied using magneto−optical Kerr microscopy and a vibrating sample magnetometer. Single-layered FeNi films having thicknesses as high as 10 nm and 40 nm show in-plane uniaxial easy magnetization axes produced by the oblique incidence of incoming components of the beams. Magnetic anisotropy field for four-layered samples with orthogonal uniaxial magnetic anisotropy axes in the adjacent layers and the thickness of individual layers of 10 nm and 40 nm turned out to be less than in single-layered films. The magnetic properties peculiarities of the eight-layered sample FeNi (10 nm) × 8 obtained by rotation of the sample holder by 45° before deposition of each subsequent layer suggest the formation of a helix-like... [more]

The automotive air conditioning (AC) electromagnetic clutch plays a crucial role in accurately controlling power transmission between the engine and the compressor, ensuring the proper operation of the AC system. The aim of this paper is to provide high-quality experimental data for researchers who are interested in simulating the dynamic process of an AC electromagnetic clutch and also to assess the adaptiveness of empirical equations to describe the AC electromagnetic clutch performance that is limited in discussion in existing studies. In this study, an automotive AC electromagnetic clutch characteristic test system was employed along with an infrared (IR) camera to conduct comprehensive experimental analyses. The test system enabled the evaluation of various parameters, including the clutch torque output, compressor exhaust pressure, and temperature of the friction surface. The results revealed that the torque and exhaust pressure were closely associated with the on/off time and ro... [more]

Parallel seam welding (PSW) is the most commonly employed encapsulation technology to ensure hermetic sealing and to safeguard sensitive electronic components. However, the PSW process is complicated by the presence of multiphysical phenomena and nonlinear contact problems, making the analysis of the dynamics of the PSW process highly challenging. This paper proposes a multiphysics simulation model based on direct coupling, enabling the concurrent coupling of the electric field, temperature field, and structural field to facilitate the analysis of the thermal and electrical dynamics within the PSW process. First, this paper conducts an in-depth theoretical analysis of thermal and electrical contact interactions at all contact interfaces within the PSW process, taking into account material properties related to temperature. Second, the acquired data are integrated into a geometric model encompassing electrode wheels and ceramic packaging components, facilitating a strongly coupled multi... [more]

The integration of distributed power generation mainly consisting of photovoltaic and wind power into active distribution networks can lead to safety accidents in grid operation. At the same time, climate change can also cause voltage fluctuations, direct current injection, harmonic pollution, frequency fluctuations, and other issues. To achieve economic and safe operation of the distribution network, an active distribution network-network planning model considering the dynamic configuration of energy storage system energy storage is constructed. This model focuses on energy storage batteries with high ease of use, high modularity, and strong mobility. The route location planning involving different load operating scenarios in spring, summer, autumn, and winter is constructed. The objective function includes the revenue from selling electricity in the distribution network, the expenditure on purchasing electricity in the distribution network, and the cost during the planned constructio... [more]

During the production of soy milk, a by-product is produced, which is typically treated as a waste material. This by-product has significant levels of dietary fibre, proteins, isoflavones and antioxidant capacity. As such, it has been recommended as an effective functional ingredient when milled to a flour after drying at 100 °C. The shelf-life stability of this dried by-product is relatively unknown when stored under different storage conditions (2 °C, 20 °C and 40 °C) and initial moisture content (9%, 12% and 14%), both packaged and exposed to immediate environments. This study investigated the impact of storage over ten weeks on the physical properties, lipid oxidation, antioxidant capacity and stability of isoflavones of this functional ingredient. The results showed that exposure significantly affected the stability of flour, especially on moisture content, water activity, isoflavone concentration and lipid oxidation. Different initial moisture contents significantly affected the... [more]

An overview of the composition of wolframite ores of the Akchatau deposit and the technologies for processing concentrates using NaOH and Na2CO3 by hydro- and pyrometallurgical methods is given, and the disadvantages associated with both the technology and the equipment are noted. To develop a technology for processing Akchatau wolframite concentrates, samples of ore materials were taken, the chemical and mineralogical composition of the samples was studied, and enrichment was carried out to obtain rich concentrates. The kinetics of the sintering of the wolframite concentrate with soda was investigated, the dependences of the degree of transformation of the tungsten minerals into sodium tungstate were obtained, and the rate constants, the order of the reaction, and the values of the apparent activation energy were calculated. The results of sintering an enlarged sample of wolframite concentrate with soda in a muffle furnace are presented. After the subsequent leaching, studies were car... [more]

In the study of borehole instability, the majority of input parameters often rely on the average values that are treated as fixed values. However, in practical engineering scenarios, these input parameters are often accompanied by a high degree of uncertainty. To address this limitation, this paper establishes a borehole stability model considering the uncertainty of input parameters, adopts the Monte Carlo method to calculate the borehole stability reliability at different drilling fluid densities, evaluates the sensitivity of borehole instability to a single parameter, and studies the safe drilling fluid density window at different borehole stability reliability values under multi-parameter uncertainties. The results show that the uncertainty of rock cohesion has a great influence on the fracture pressure of the vertical and horizontal wells. The minimum horizontal stress has the greatest influence on the fracture pressure of the vertical and horizontal wells, followed by pore pressu... [more]

The utilization of auxiliary tools employing ultrasonic high-frequency vibration to enhance rock breaking efficiency holds significant potential for application in underground hard rock excavation engineering. To investigate the failure mechanism of rocks under high frequency ultrasonic vibration load, this study employs particle flow software PFC2D for numerical simulation. By incorporating boundary conditions from actual ultrasonic vibration rock breaking experiments and utilizing a parallel bond model to construct the rock, we analyze the deformation, damage, fracture, and energy evolution process of hard rocks subjected to vibrational loads. The results demonstrate that the maximum displacement in hard rocks increases nearly linearly with vibrations until reaching 5.0199 × 10−3 m, after which it plateaus. Additionally, macroscopic fissures formed during rock failure exhibit an X-shaped pattern. Furthermore, based on our model, we examine the impact of amplitude variation on hard ro... [more]

Knowledge of the chemical changes caused during plasma treatment is essential to enhance food quality. In this work, the influence of two cold plasma technologies, dielectric barrier discharge plasma and glow discharge plasma, on the phenolic profile of araça-boi (Eugenia stipitata) juice was investigated and assessed by gas chromatography coupled to mass spectrometry. Eight phenolic compounds were identified in araça-boi, with cinnamic acid being the major phenolic compound of the fruit juice, followed by protocatechuic acid. The effects of excitation frequency and plasma flow rate were evaluated because these are the main operating conditions that can be set for plasma treatments. The phenolic profile slightly changed due to the reaction of the phenolics with the reactive plasma species produced during the treatment, with the highest increase in phenolic content observed in the dielectric barrier discharge plasma operating at 1000 Hz. Both plasma systems increased the bioavailability... [more]

Solid−liquid flows are encountered in various industrial and natural environments. The internal structure of such flows is highly sensitive to the grading of the solid particles present. In this experimental study, an extended stereometric method is employed to assess the distributions of velocity of particles of different fractions, distinguished by different colors, in vertical and nearly horizontal granular flows. In the vertical flow experiments, mixtures comprising three fractions of lightweight particles, characterized by a very similar density, size, and shape, were tested. The results affirmed the method’s ability to discern particle velocity differences on the order of millimeters per second, establishing its suitability for characterizing nearly horizontal open-channel flows with bimodal mixtures that are stratified and exhibit more complex velocity distributions. Tilting flume experiments, incorporating additional measurements of water velocity distribution, allowed for the... [more]

Hydraulic vibrations in Francis turbines caused by cavitation profoundly impact the overall hydraulic performance and operational stability. Therefore, to investigate the influence of cavitation phenomena under high-load conditions, a three-dimensional unsteady numerical simulation is carried out for a Francis turbine with different head operating conditions, which is combined with the SST k-w turbulence model and two-phase flow cavitation model to capture the evolution of cavitation under high-load conditions. Additionally, utilizing entropy production theory, the hydraulic losses of the Francis turbine during cavitation development are assessed. Contrary to the pressure-drop method, the entropy production theory can quantitatively reflect the characteristics of the local hydraulic loss distribution, with a calculated error coefficient τ not exceeding 2%. The specific findings include: the primary sources of energy loss inside the turbine are the airfoil cavitation and cavitation vort... [more]

This paper studies an improved super-twisting sliding mode controller (IST-SMC) for the permanent magnet synchronous generator (PMSG) voltage loop to improve the anti-disturbance capability of the system. Compared to conventional voltage controllers, the control algorithm provides advantages in terms of system resistance to load disturbances. Conventional voltage controllers have significant voltage fluctuations and long recovery times during sudden load changes. To solve this problem, a voltage loop controller based on a super-twisting sliding mode (ST-SMC) is designed to enhance the immunity of the system. Also, the ST-SMC was improved to further increase the convergence rate of the system and enhance the dynamic performance. The convergence of the system away from the balance point is accelerated by introducing an exponential term, which in turn provides an improvement in the dynamic performance of the system. The effectiveness of the proposed control scheme was verified on a PMSG.

High-performance aeroengine design is an important component of modern industry, and advanced sealing technology is a key technology to meet the engine fuel consumption rate, thrust-to-weight ratio, pollutant emission, durability, and lifetime. Reducing the internal airflow leakage of the engine through a sealing technology can improve the performance and efficiency of the engine. In this paper, the typical sealing technology for an aeroengine is introduced in more detail, including the structural characteristics and use limitations of the labyrinth seal, brush seal, honeycomb seal, gas film face seal, and cylindrical gas film seal. It focuses on the development history, typical structure type, working principle, basic technology research method, steady-state performance, dynamic characteristics, multi-physical field coupling, structural deformation, experimental testing, processing technology. Finally, it summarizes the problems and future development trends of the current application... [more]

Nanofluid Minimum Quantity Lubrication (NMQL) is a resource-saving, environmentally friendly, and efficient green processing technology. Therefore, this study employs Minimum Quantity Lubrication (MQL) technology to conduct milling operations on aerospace 7050 aluminum alloy using soybean oil infused with varying concentrations of MoS2 and MWCNTs nanoparticles. By measuring cutting forces, cutting temperatures, and surface roughness under three different lubrication conditions (dry machining, Minimum Quantity Lubrication, and nanofluid minimum quantity lubrication), the optimal lubricating oil with the best lubrication performance is selected. Under the conditions of hybrid nanofluid minimum quantity lubrication (NMQL), as compared to dry machining and Minimum Quantity Lubrication (MQL) processing, surface roughness was reduced by 48% and 36% respectively, cutting forces were decreased by 35% and 29% respectively, and cutting temperatures were lowered by 44% and 40%, respectively. Unde... [more]

Gas leaks can cause disasters at process sites, including fires and explosions, and thus, effective gas-leak detection systems are required. This study investigated the limitations of conventional detectors and introduced an innovative ultrasonic sensor-based approach for continuous monitoring. A new configuration for a stationary remote ultrasonic gas-leak monitoring system is proposed. The selected material was 1-Butene. The detection probability was assessed through a simulation based on a gas-leak scenario, detailing the selection criteria for leak sites and simulation conditions. Computational fluid-dynamics (CFD) simulations were used to evaluate the detection capability of the existing system, whereas Monte Carlo simulations were used to compare it with the proposed ultrasonic system. The CFD simulation was performed by setting the lower detection limit of the concentration-measurement-type gas detector to 600 ppm, and the leak-detection time was approximately 8.895 s. A Monte C... [more]

The rational structural design of polycrystalline diamond compact (PDC) cutters effectively enhances the performance of drill bits in rock fragmentation and extends their service life. Inspired by bionics, a bionic PDC cutter was designed, taking the mole claw toe, shark tooth, and microscopic biomaterial structures as the bionic prototypes. To verify its rock-breaking effectiveness, the finite element method was employed to compare the rock-breaking processes of the bionic cutter, triangular prism cutter, and axe cutter. The study also investigated the influence of different back rake angles, cutting depths, arc radii, and hydrostatic pressures on rock breaking using the bionic cutter. Prior to this, the accuracy of the finite element model was validated through laboratory tests. Subsequently, a drill bit incorporating all three types of cutters was constructed, and simulations of rock breaking were conducted on a full-sized drill bit. The results demonstrate that the bionic cutter ex... [more]

Model uncertainty creates a largely open challenge for industrial process control, which causes a trade-off between robustness and performance optimality. In such a case, we propose a generalized conditional feedback (GCF) system to largely eliminate conflicts between robustness and performance optimality. This approach leverages a nominal model to design an optimal control in the virtual domain and defines an ancillary feedback controller to drive the physical process to track the trajectory of the virtual domain. The effectiveness of the proposed GCF scheme is demonstrated in a simulation for six typical industrial processes and three model-based control methods, and in a half-quadrotor system control test. Furthermore, the GCF scheme is open to existing optimal control and robust control theories.

A waste material cannot truly be called waste when the procedures and technologies have been invented and developed to exploit and utilize it [...]

In order to achieve efficient photocatalytic N2 reduction activity for ammonia synthesis, a photochemical strategy was used in this work. UiO-66 was prepared through the solvothermal method and further loaded with Au nanoparticles (Au NPs) onto the UiO-66 (Zr) framework. The experimental results verified that there were metal−support interactions between Au NPs and UiO-66; this could facilitate charge transfer among Au NPs and UiO-66, which was beneficial to enhance the photocatalytic activity. The best N2 fixation effect of Au/UiO-66 with a loading of 1.5 wt% was tested, with a photocatalytic yield of ammonia of 66.28 μmol g−1 h−1 while maintaining good stability. The present work provides a novel approach to enhancing photocatalytic N2 fixation activity by loading NPs onto UiO-66.

It is important for data modeling to comply with a data observation window of physical variables behind the data. In this paper, a multivariate data alignment method is proposed to follow different time scales and different role effects. First, the length of the sliding windows is determined by the frequency characteristics of the time-series reconstruction. Then, the time series is aligned to the length of the window by a sequence-to-sequence neural network. This neural network is trained by replacing the loss function with dynamic time warping (DTW) in order to prevent the losses of the time series. Finally, the attention mechanism is introduced to adjust the effect of different variables, which ensures that the data model of the matrix is in accord with the intrinsic relation of the actual system. The effectiveness of the approach is demonstrated and validated by the Tennessee Eastman (TE) model.