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]

The inorganic-carbonate dual-phase membrane represents a class of dense membranes that are fabricated using diverse support materials, ranging from metals to ceramics. This dual-phase membrane consists of a porous metal or ceramic support with an introduced carbonate phase within the support pores. Compared with polymer and zeolite membranes, inorganic-carbonate dual-phase membranes exhibit exceptional CO2 selectivity at elevated temperatures (>500 °C), making them an ideal choice for high-temperature CO2 separation in power plant systems. The present paper provides a comprehensive overview of the separation principle, significant models, and preparation techniques employed in carbonate dual-phase membranes for CO2 separation. The present study aims to discuss key factors that limit the CO2 permeation performance and stability of membranes, while also exploring the potential applications of dual-phase membranes in various fields. The identification of key challenges in the future devel... [more]

In addition to main fractures, a large number of secondary fractures are formed after the volumetric fracturing of shale gas wells. The secondary fracture properties are so complex, that it is difficult to identify and diagnose by direct monitoring methods. In this study, a new approach to model and diagnose secondary fracture properties is presented. First, a new pressure decline model, which is composed of four interconnected domains, i.e., wellbore, main fractures, secondary fractures, and reservoir matrix pores, is built. Then, the fracturing fluid pumping and post-fracturing soaking processes are simulated. The simulated pressure derivatives reflect five fracture-dominated flow regimes, which correspond to multiple alternating positive and negative slopes of the pressure decline derivative. The results of sensitivity simulation show that the density, permeability, and width of secondary fractures are the main controlling factors affecting the size ratio. Finally, based on the simu... [more]

In Section 4 of the original publication [...]

Pectinase, a kind of hydrolase, mainly contains polygalacturonase, pectinase, and pectin lyase, which can hydrolyze pectin to generate galacturonide and is widely used in industry. At present, pectinase’s activity is still relatively low. Hyperactive pectinase was produced with solid-phase fermentation and a tray bioreactor using the novel strain Aspergillus sp. CM96 in this study. This pectinase’s activity can reach 17,000 U·g−1 after fermentation with a tray bioreactor, an increase of 86% compared to that obtained using flask liquid fermentation. The pectinase was purified and its characteristics were explored. Additionally, during pectinase fermentation, the activities of protease, glucanase, and cellulase were also determined to reach 7000, 8000, and 3000 U·g−1. The enzyme mixture was used to improve substrate digestion efficiency in 144 Soviet white pigs after adding a 0.05% cocktail enzyme for 38 days. The results showed that the average daily gain (ADG) increased by 139.41 ± 1.0... [more]

This study investigated the characteristics of radiofrequency, middle-pressure argon plasma used in the atomic layer deposition (ALD) of Al2O3 films. Based on the electrical characteristics—the current, voltage, and phase shift between them—and the stability of the plasma plume, the optimum plasma power, allowing reliable switching on of the plasma for any step of an ALD cycle, was determined. Spectral measurements were performed to determine the gas temperature and reactive species that could be important in the ALD process. The density of metastable argon atoms was estimated using tunable laser absorption spectroscopy. It was concluded that plasma heating of substrates did not affect film growth. The crystallization-enhancing effect of plasma observed in these experiments was due to the action of OH radicals produced in the plasma.

Kazakhstan has abundant resources of low-permeability oil reservoirs, among which the KKM low-permeability oil reservoir has geological reserves of 3844 × 104 t and a determined recoverable reserve of 1670 × 104 t. However, the water flooding efficiency is only 68%, and the recovery efficiency is as low as 32%. The development of the reservoir faces challenges such as water injection difficulties and low oil production from wells. In order to further improve the oil recovery rate of this reservoir, our team developed micro-pressure-driven development technology based on pressure-driven techniques by integrating theories of fluid mechanics and artificial intelligence. We also combined this with subsequent artificial lift schemes, resulting in a complete set of micro-pressure-driven process technology. The predicted results indicate that after implementing micro-pressure-driven techniques, a single well group in the KKM oilfield can achieve a daily oil production increase of 32.08 t, dem... [more]

Rapid detection and sensitive analysis of MMZ is of great importance for food safety. Herein, a fluorescent molecularly imprinted sensor based on upconversion nanoparticles (UCNPs) grafted onto covalent organic frameworks (COFs) was designed for the detection of MMZ. COFs with a high specific surface area and excellent affinity serve as substrates for grafting of UCNPs, which can inhibit the aggregation burst of UCNPs and improve the mass transfer rate of the sensor. Through a series of characterizations, it was found that the proposed UCNP-grafted COFs@MIP-based sensor had good optical stability, high adsorption efficiency, strong anti-interference ability, and high sensitivity owing to the integration of the advantages of UCNPs, COFs and MIPs. Under the optimal conditions, a good linear relationship was presented between the fluorescence intensity of UCNP-grafted COFs@MIPs and the methimazole concentration in the range of 0.05−3 mg L−1, and the detection limit was 3 μg L−1. The as-pr... [more]

Internal recycle quadruple fluidized bed pyrolyzer (IR-QFBP) consists of a dual fluidized bed pyrolyzer and a dual fluidized bed combustor and is proposed in this work. It is a new kind of efficient fluidized bed with high pyrolysis and energy efficiency. IR-QFBP may attract extensive attention because of its compact structure. Cold hydrodynamic characteristics of IR-QFBP are the bases of modeling and designing for the hot one. To fully understand the hydrodynamic characteristics of IR-QFBP, a cold flow model on a laboratory scale was designed and set up; furthermore, the two-fluid model (TFM) based simulation was also carried out. The pressure profiles, fluidization states, velocity profiles, and circulation rates of a solid powder at different operation conditions in IR-QFBP were investigated. The results showed that the stable internal circulation of solid powder can be achieved in IR-QFBP. And different circulation characteristics can be obtained by adjusting the operating conditio... [more]

Enzymatic additives, particularly alkaline proteases, play a crucial role in enhancing detergent effectiveness against protein-based stains. Despite advancements in enzyme stabilization techniques, there is a need for innovative strategies to further improve protease stability in laundry detergents. However, research exploring the utilization of substrate imprinting technology to achieve this objective remains limited. Therefore, this study aims to enhance the stability of alkaline proteases in laundry detergents by employing casein as an imprinting substrate and utilizing transglutaminase-mediated (TGase) crosslinking to modify proteases 102 and 306. The optimal temperature, pH, and thermal stability of the modified alkaline proteases 102 and 306 showed no significant changes. However, these two modified alkaline proteases exhibited varying degrees of improvement in stability among the 14 detergent additives tested. Under 40 °C incubation for 24 h, the relative enzyme activity of modi... [more]

The objective of this inquiry is to illuminate the attributes of heavy metal contamination and evaluate the potential ecological hazards inherent in the surface soil of Chenzhou City. A comprehensive analysis was conducted on 600 systematically collected soil samples within the study area, utilizing enrichment factors, geo-accumulation indices, comprehensive pollution indices, potential ecological hazard indices, and health risk assessment models to evaluate the degree of heavy metal contamination in the soil, potential ecological risks, and associated health hazards. The findings reveal that the average enrichment factor (EF) for each heavy metal is below 2, with the hierarchy from highest to lowest being Hg > Cd > Cu > Pb > Ni > Zn > Cr > As. Approximately 78.67% of soil samples exhibit no pollution to weak pollution levels based on heavy metal enrichment factors. Moreover, the comprehensive pollution index (IPIN) indicates that 95.17% of soil samples are within safe and pollution-fr... [more]