The unprecedented growth of distributed renewable generation is changing the distribution network from passive to active, resulting in issues like reverse power flow, voltage violations, malfunction of protection relays, etc. To ensure the reliable and flawless operation of active distribution networks, an electrical device enabling active network management is necessary, and a hybrid distribution transformer offers a promising solution. This study introduces a novel hybrid transformer topology and multi-mode control strategy to achieve coordinated voltage and reverse power regulation in active distribution networks. The proposed hybrid transformer combines conventional transformer windings with a partially rated SiC-MOSFET-based back-to-back converter, reducing additional investment costs and enhancing system reliability. A multi-mode control strategy is proposed to facilitate the concurrent reverse power control and voltage violation mitigation of the presented hybrid transformer, al... [more]

The development of efficient and low-cost non-metallic catalysts is of great significance for the oxygen reduction reaction (ORR) in fuel cells. Heteroatom-doped carbon-based catalysts are one of the popular candidates, although their preparation method is still under exploration. In this work, single (CS)-, double (NCS)-, and triple (NBCS)-heteroatom-doped carbon-based catalysts were successfully prepared by a “cook-off” process. The morphology, elemental composition, and bonding structure of the catalysts were investigated by SEM, TEM, Raman spectra, BET, and XPS. ORR catalytic performance measurements suggested an activity trend of CS < NCS < NBCS, and NBCS demonstrated better methanol resistance and slightly higher stability than the commercial Pt/C catalyst, as evaluated with both rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) systems. The mechanism for the promoted performance was also proposed based on the conductivity of the catalysts. In this paper... [more]

With the development of society and urbanization, higher requirements have been put forward for the safety and seismic resistance of building structures. The fatigue strength and seismic performance of welded joints have received close attention, especially as a crucial part of building steel structure. This study used the finite element simulation method to analyze the stress-strain of welded joints in building steel structures, and explore the influence of residual stress on their seismic performance. A stress-strain calculation model for welded joints in building steel structures was studied and constructed, and the accuracy of the model was verified through numerical calculation methods. The results showed that the residual stress peaks of the horizontal and vertical directions of the V-groove welded joint structure were 475 MPa and 325 MPa, respectively, and the longitudinal residual stress peaks were 525 MPa and 425 MPa, respectively. The seismic performance of four different ste... [more]

As global efforts intensify to transition toward cleaner and more sustainable energy sources, the blending of hydrogen with natural gas emerges as a promising strategy to reduce carbon emissions and enhance energy security. This study employs a systematic approach to assess the economic viability of hydrogen blending, considering factors such as gas costs and heat values. Various hydrogen blending scenarios are analyzed to determine the optimal blend ratios, taking into account both technical feasibility and economic considerations. The study discusses potential economic benefits, challenges, and regulatory implications associated with the widespread adoption of hydrogen−natural gas mixtures. Furthermore, the study explores the impact of this integration on existing natural gas infrastructure, exploring the potential for enhanced energy storage and delivery. The findings of this research contribute valuable insights to policymakers, industry stakeholders, and researchers engaged in the... [more]

This article presents computational fluid dynamics (CFD) modeling of the flow processes at a certain specimen of an external gear pump. The purpose of the developed two-dimensional (2D) CFD model is to carry out a numerical study to obtain the main characteristics of the pump flow rate, especially the flow rate as a function of the pressure and the flow rate as a function of the time. A numerical study was carried out at forty-two different operating modes that were expressed as a variation of two parameters: rotational frequency (950−1450 min−1) and pressure (5−150 bar). The validation of the numerical results was carried out through an experimental study. For this purpose, a laboratory experimental setup equipped with a modern data acquisition (DAQ) system was designed and implemented. It allows the gear pump to be tested at the same operating modes as the numerical study. A validation analysis was performed by comparing the numerical and experimental results using the average relati... [more]

The drying process of polymeric coatings, particularly in the presence of surfactants, poses a complex challenge due to its intricate dynamics involving simultaneous heat and mass transfer. This study addresses the inherent complexity by employing Artificial Neural Networks (ANNs) to model the surfactant-enhanced drying of poly(styrene)-p-xylene coatings. A substantial dataset of 16,258 experimentally obtained samples forms the basis for training the ANN model, showcasing the suitability of this approach when ample training data is available. The chosen single-layer feed-forward network with backpropagation adeptly captures the non-linear relationships within the drying data, providing a predictive tool with exceptional accuracy. Our results demonstrate that the developed ANN model achieves a precision level exceeding 99% in predicting coating weight loss for specified input values of time, surfactant amount, and initial coating thickness. The model’s robust generalization capability e... [more]

In order to address the time-consuming and labor-intensive challenges as well as the suboptimal operational quality encountered in the conventional processes of fruit bagging within expansive orchards, an innovative end-of-bagging actuator is proposed, which can be installed on a fruit-production robot. Due to the excessive power sources required to complete the bagging operation, while also taking into account the quality and cost of the end effector, we have implemented a clutch transmission system to control individual motors, thereby achieving efficient bag-opening and collection actions. Through kinematic analysis of the bagging end effector, the optimal bag opening size is determined to be 40.3372 mm, with a deviation of 0.1428 mm from the design target and an error rate of 0.35%. This ensures the desired bag size for bagging juvenile fruits. Moreover, a dynamic simulation model comprising rigid drive components and a flexible clutch was developed. The simulation results demonstr... [more]

Lignocellulosic biomass holds promise as a renewable feedstock for various applications, but its efficient conversion requires cost-effective degradation strategies. The main objective of this study was to investigate the effect of the growth conditions of Cellulomonas phragmiteti in the production of (hemi)cellulosic supernatants. To meet this aim, different lignocellulosic residues were used as carbon sources for growth using defined mineral or nutritive culture media. Cell-free culture supernatants with xylanolytic activity were produced in all the conditions evaluated, but the highest xylanase activity (15.3 U/mL) was achieved in Luria−Bertani (LB) medium containing 1% waste paper. Under these conditions, almost negligible β-glucosidase, cellobiohydrolase, β-xylosidase, and α-arabinofuranosidase activity was detected. The xylanolytic supernatant showed tolerance to salt and displayed maximal catalytic efficiency at pH 6 and 45 °C, along with good activity in the ranges of 45−55 °C... [more]

In order to meet the mechanical property of the die steel, this study used laser cladding to prepare a high-entropy alloy coating on Cr12MoV. A finite element method using a double ellipsoidal heat source model is proposed to simulate the evolution of the temperature field in laser cladding. The simulation results showed that with the increase in the power, the peak temperature of the molten pool increased from 2005.5 °C to 2357.4 °C, and the depth of the molten pool increased from 1.60 mm to 2.04 mm. The coating with the laser power of 1600 W had a good macroscopic quality and high lattice distortion (2.43 × 10−2). Due to the increase in laser energy density, the size of equiaxed crystals gradually increased from 1400 W to 1700 W. Under the comprehensive effect of the solution and fine grain strengthening, the coating with the power of 1600 W had a higher average microhardness (600 HV), which is 150% higher than that of the substrate. The experiment results further confirmed the accur... [more]

Direct numerical simulations of temporally evolving high-temperature supersonic turbulent channel flow for chemical equilibrium were conducted with a Mach number of 3.0, a Reynolds number of 4880, and a wall temperature of 1733.2 K to investigate the influence of the viscosity law. The mean and fluctuating viscosity for the mixture rule is higher than that for Sutherland’s law, whereas an opposite trend is observed in the mean temperature, mean pressure, and dissociation degree. The Trettel and Larsson transformed mean velocity, the Reynolds shear stress, the turbulent kinetic energy budget, and the turbulent Prandtl number are insensitive to the viscosity law. The semilocal scaling that take into account local variation of fluid characteristics better collapses the turbulent kinetic energy budget. The modified strong Reynolds analogies provide reasonably good results for the mixture rule, which are better than those for Sutherland’s law. The streamwise and spanwise coherencies for the... [more]

Flow stability is extremely important for hydraulic turbines, especially for 1 GW hydraulic turbines, and has a strong impact on mesh stability. However, turbines often operate under non-design conditions, and current research on this aspect is still lacking. So a model of the fluid domains of a high-quality installed 1 GW Francis turbine was established to investigate the flow characteristics of the turbine and fluid domains. CFD simulations of a 1 GW Francis turbine under rated load and overload operation conditions were performed. According to simulation results, when the turbine is under the overload operation condition, the internal flow stability of the 1 GW hydraulic turbine can be obviously different from that of the rated load. In the overload condition, the flow field is more turbulent and a large number of vortices are generated in the draft tube, resulting in significant changes in pressure, flow rate, and output. In order to improve calculation accuracy, a pure clearance m... [more]

This study presents a model-based deep reinforcement learning (MB-DRL) controller for the fluidized bed biomass gasification (FBG) process. The MB-DRL controller integrates a deep neural network (DNN) model and a reinforcement learning-based optimizer. The DNN model is trained with operational data from a pilot-scale FBG plant to approximate FBG process dynamics. The reinforcement learning-based optimizer employs a specially designed reward function, determining optimal control policies for FBG. Moreover, the controller includes an online learning component, ensuring periodic updates to the DNN model training. The performance of the controller is evaluated by testing its control accuracy for regulating synthetic gas composition, flow rate, and CO concentration in the FBG. The evaluation also includes a comparison with a model predictive controller. The results demonstrate the superior control performance of MB-DRL, surpassing MPC by over 15% in regulating synthetic gas composition and... [more]

Microfiltration is an important process in the pharmaceutical industry. Filter selection and validation is a time-consuming and expensive process. Quality by design approach is important for product safety. The article covers the instrumentalization and process control of a laboratory-scale dead-end microfiltration layout. The layout is a downscale model of the actual production line, and the goal is filter validation and analysis of process parameters, which may influence filter operation. Filter size, fluid pressure, valve plunger speed, and timing issues were considered. The focus is on the identification of the most influential process parameters and their influence on the repeatability of pressure oscillations caused by valve opening. The goal was to find the worst-case scenario regarding pressure oscillations and, consequently, filter energy intake. The layout was designed as compact as possible to reduce pressure losses between the filter and valve. Valve-induced pressure oscill... [more]

The residual antibiotics in livestock excreta (LE) have been regarded as a potential threat to the ecosystem and human society. Some photoautotrophic microalgae, however, were found to metabolize them during active biomass photosynthesis. This study investigates how the strength of the antibiotics impacts the overall biodiesel yield and composition of the harvested microalgal biomass grown from LE. The microalgal growth results demonstrate that increasing the concentration of residual antibiotics suppresses the microalgal growth rate from 0.87 d−1 to 0.34 d−1. This 61% lower biomass production rate supports the proposition that the kinetic impact of antibiotics may slow lipid synthesis. Moreover, the analytical results of fatty acid methyl ester (FAME) demonstrate that amoxicillin substantially reduces the C16:0 content by over 96%. This study evidences that the functional group similarity of amoxicillin may competitively inhibit the esterification reaction by consuming methanol. This... [more]

This paper presents a comprehensive review of the historical development, the current state of the art, and prospects of data-driven approaches for industrial process monitoring. The subject covers a vast and diverse range of works, which are compiled and critically evaluated based on the different perspectives they provide. Data-driven modeling techniques are surveyed and categorized into two main groups: multivariate statistics and machine learning. Representative models, namely principal component analysis, partial least squares and artificial neural networks, are detailed in a didactic manner. Topics not typically covered by other reviews, such as process data exploration and treatment, software and benchmarks availability, and real-world industrial implementations, are thoroughly analyzed. Finally, future research perspectives are discussed, covering aspects related to system performance, the significance and usefulness of the approaches, and the development environment. This work... [more]

Due to the large inertia and strong impact accompanying the free-falling hook process of crawler cranes, it is difficult to meet the demand for flexible and smooth braking control under different weight load conditions. Therefore, this paper takes the free-fall hook system as the research object and combines system operation characteristics and control theory to carry out research on flexible braking control of the free-fall hook system. Firstly, a joint simulation platform of MATLAB (version 2018b) and AMESim (version 2019.1) software is built to theoretically analyze the key components of the free-fall hook system (proportional pressure-reducing valve, winch reducer, and wet clutch). Secondly, a mathematical model of the braking process is established, and the pressure control demand is clarified to analyze the reasons for the existence of dead zones and hysteresis loops in the system. Meanwhile, it is found that the dead zones and hysteresis loops existing in the pressure output of... [more]

The hydrogen cycle system, one of the main systems used for hydrogen fuel cells, has many advantages. It can improve the efficiency, the water capacity, and the management of thermal fuel cells. It can also enhance the safety of the system. Therefore, it is widely used in hydrogen fuel cell vehicles. We introduce the structure and principles of hydrogen cycle pumps, ejectors, and steam separators and analyze and summarize the advantages of the components, as well as reviewing the latest research progress and industrialization status of hydrogen cycle pumps and ejectors. The technical challenges in hydrogen circulation systems and the development direction of key technologies in the future are discussed. This paper aims to provide a reference for research concerning hydrogen energy storage application technology in hydrogen fuel cell systems.

A solid-phase microextraction (SPME) injection gas chromatography was validated with the flame ionization detection method (GC-FID) using a capillary column to detect ethanol. The method was used to determine ethanol in fluids with biomedical, clinical, and forensic importance, including water, phosphate-buffered saline (PBS), and artificial sweat. The strategy produced good peak resolution and showed a linear correlation between the concentration and peak areas for ethanol in all matrices. The inter- and intra-day precisions of the method were below 15.5% and 6.5%, respectively, varying according to the matrix. The method achieved detection limits below 1.3 mg/L, varying according to the matrix. Lower limits were obtained for the aqueous solution (0.22 mg/L), followed by the PBS solution (0.96 mg/L), and finally, the sweat solution (1.29 mg/L). This method is easy to perform and suitable for use in routine clinical biochemistry and forensic laboratories, allowing ethanol detection at... [more]

Data fusion, which involves integrating information from multiple sources to achieve a specific objective, is an essential area of contemporary scientific research. This article presents a multimodal fusion system for object identification in point clouds in a controlled environment. Several stages were implemented, including downsampling and denoising techniques, to prepare the data before fusion. Two denoising approaches were tested and compared: one based on neighborhood technique and the other using a median filter for each “x”, “y”, and “z” coordinate of each point. The downsampling techniques included Random, Grid Average, and Nonuniform Grid Sample. To achieve precise alignment of sensor data in a common coordinate system, registration techniques such as Iterative Closest Point (ICP), Coherent Point Drift (CPD), and Normal Distribution Transform (NDT) were employed. Despite facing limitations, variations in density, and differences in coverage among the point clouds generated by... [more]

Given the lack of accurate and reliable discrete element simulation parameters to study the interactions between soft soil and soil casting components after ginseng land cultivation in Northeast China and the design of ginseng land-specific borders, this paper calibrates the relevant model parameters of ginseng soil using the Hertz−Mindlin with JKR contact model in EDEM to standardize the contact parameters between soil particles and between soil and Q235 steel in soft soil after cultivation in ginseng land. Taking the soil particle accumulation angle as the response value, a Box−Behnken design (BBD) was introduced to establish a regression model for the soil accumulation angle; the surface energy, static friction coefficient, rolling friction coefficient, and coefficient of restoration parameters were obtained, respectively, through the optimization of the model, at which time, the simulated value of the soil accumulation angle was 37°, which is a 4% relative error to the actual measu... [more]

Pouring semi-flexible pavement material (PSFM) is widely used as a wearing layer material or below pavement due to its excellent resistance to deformation at high temperatures and under heavy loads. However, in cold regions, the material exhibits severe cracking issues. The primary objective of this study is to enhance the resistance of pouring semi-flexible pavements (SFPs) to low-temperature cracking in cold regions by strategically designing pavement structures that incorporate PSFM. To achieve this goal, we conducted indoor tests to determine the relaxation modulus and temperature shrinkage coefficient of PSFM and simulated a pavement structure using COMSOL finite element simulation. The impacts of different application layers and layer thicknesses on low-temperature stresses were investigated based on these findings. The research findings indicate that when PSFM is used as the wearing layer material, the low-temperature stress is 4.7% lower than that of typical materials used in t... [more]

is one of the oilseeds in the Brassicaceae family, possessing seed quality traits such as oil with various fatty acid profiles suitable for many industrial applications. Determination of such quality traits using conventional methods is often expensive, time-consuming, and destructive. In contrast, the Near-Infrared Spectroscopic (NIRS) technique has been proven fast, cost-effective, and non-destructive for the determination of seed compositions. This study aimed to demonstrate that NIRS is a rapid and non-destructive method for determining the fatty acid profile and oil content in diverse germplasms of B. carinata. A total of 96 genetically diverse B. carinata germplasms that include accessions, advanced breeding lines, and varieties were used in this study. Reference data sets were generated using gas chromatography and the Soxhlet oil extraction method for fatty acid profile and oil content, respectively. Spectra data were taken from the wavenumber range of 11,500 to 4000 cm−1 using... [more]

Aerobic granular sludge (AGS) represents a significant advancement in wastewater treatment technology [...]

Glioblastoma is one of the most aggressive and lethal brain tumors. Due to the failure of conventional chemotherapies and targeted drugs pursuit of natural, less toxic agents is on the rise as well as their utilization in glioblastoma treatment. Consequently, this study explores the antiproliferative potential of selected berry juices (wild blackberry (Rubus discolor), dwarf elderberry (Sambucus ebulus), and raspberry (Rubus idaeus)) on glioblastoma cells (U87-MG and GBM43) in comparison to temozolomide. The juices were assessed for total phenolic content, proanthocyanins, polyphenol profiles, and antioxidant activity. Wild blackberry and dwarf elderberry juices exhibited higher total polyphenols, proanthocyanins, and monomeric anthocyanins compared to raspberry juice. HPLC analysis revealed distinctive anthocyanins, flavonoids, and phenolic acids in each juice. With the DPPH assay, the highest antioxidant potential had wild blackberry juice, while with other assays dwarf elderberry ju... [more]

In the preparation of high specific surface area activated carbon (AC) by KOH activation, the swelling of the reactant mixture and the particles’ agglomeration deteriorates the process and the property of product. In this study, a novel method using a rotary kiln loaded with steel balls has been developed for the preparation of AC from petroleum coke (PC) by KOH activation. It has been found that the molten KOH caused the swelling of the reaction mixture at a lower activation temperature, while the molten K2O led to the particles’ agglomeration at a higher temperature. The steel balls could relieve the swelling and agglomeration and enhance the pore structure development of the AC by boosting the heat and mass transfer in the reactor. At an activation temperature of 800 °C and a KOH/PC mass ratio of 3:1, the specific surface area of the AC obtained without the addition of steel balls in the kiln is 1492 m2/g, while that with the steel balls is 1996 m2/g. The introduction of CO2 during... [more]