Processes

19 pages, 5904 KiB

Open AccessArticle

Small-Signal Stability Analysis of Grid-Connected System for Renewable Energy Based on Network Node Impedance Modelling

by Lifu He, Dingshan Liu, Haidong Tao, Yangwu Shen, Jiapeng Ren, Yuting Wang, Jin Li and Yaqin Xu

Processes 2025, 13(5), 1292; https://doi.org/10.3390/pr13051292 - 23 Apr 2025

Abstract

As distributed renewable energy is integrated into the power grid, the issue of small-signal stability arising from the interaction between the grid-connected converters and the grid-side impedance cannot be overlooked. However, when multiple converters for renewable energy are interconnected, the system topology becomes [...] Read more.

As distributed renewable energy is integrated into the power grid, the issue of small-signal stability arising from the interaction between the grid-connected converters and the grid-side impedance cannot be overlooked. However, when multiple converters for renewable energy are interconnected, the system topology becomes complex, making it difficult to delineate the source and grid subsystems. This poses challenges for analyzing the interactive stability among the control loops of grid-connected converters and network impedance. To address this, this article establishes a small-signal impedance model for a grid-connected system. By deriving the transfer functions of individual control loops through the control block diagram, the stability influencing factors for specific control parameters can be analyzed. Furthermore, a stability analysis method for systems with multiple grid-connected converters based on a network node impedance model is proposed. This method enables the determination of stability for grid-connected converters connected at different node locations, providing a theoretical reference for the stability analysis of grid-connected systems. Full article

(This article belongs to the Special Issue Control and Optimization of Smart Grids, Microgrid Systems and Active Distribution Networks)

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23 pages, 6864 KiB

Open AccessArticle

An Unresolved SPH-DEM Coupling Framework for Bubble–Particle Interactions in Dense Multiphase Systems

by Ying Tian, Guanhua An, Xiangwei Dong, Rui Chen, Zhen Guo, Xuhe Zheng and Qiang Zhang

Processes 2025, 13(5), 1291; https://doi.org/10.3390/pr13051291 - 23 Apr 2025

Abstract

This study presents a novel unresolved SPH-DEM coupling framework to investigate the complex interactions between rising gas bubbles and sinking solid particles in multiphase systems. Traditional numerical methods often struggle with large deformations, multiphase interfaces, and computational efficiency when simulating dense particle-laden flows. [...] Read more.

This study presents a novel unresolved SPH-DEM coupling framework to investigate the complex interactions between rising gas bubbles and sinking solid particles in multiphase systems. Traditional numerical methods often struggle with large deformations, multiphase interfaces, and computational efficiency when simulating dense particle-laden flows. To address these challenges, the proposed model leverages SPH’s Lagrangian nature to resolve fluid motion and bubble dynamics, while the DEM captures particle–particle and particle–bubble interactions. An unresolved coupling strategy is introduced to bridge the scales between fluid and particle phases, enabling efficient simulations of large-scale systems with discrete bubbles/particles. The model is validated against benchmark cases, including single bubbles rising and single particle’s sedimentation. Simulation studies reveal the effects of particle/bubble number and initial distance on phase interaction patterns and clustering behaviors. Results further illustrate the model’s capability to capture complex phenomena such as particle entrainment by bubble wakes and hindered settling in dense suspensions. The framework offers a robust and efficient tool for optimizing industrial processes like mineral flotation, where bubble–particle dynamics play a critical role. Full article

(This article belongs to the Special Issue Innovative Meshless Methods for Multiphase Flows and Fluid–Structure Interaction Problems)

17 pages, 11168 KiB

Open AccessArticle

pH-Responsive Gold Nanoparticle/PVP Nanoconjugate for Targeted Delivery and Enhanced Anticancer Activity of Withaferin A

by Velmurugan Sekar, Amutha Santhanam and Paulraj Arunkumar

Processes 2025, 13(5), 1290; https://doi.org/10.3390/pr13051290 - 23 Apr 2025

Abstract

The development of advanced high-capacity nanoparticle-based drug loading, precise targeting, low toxicity, and excellent biocompatibility is critical for improving cancer therapeutics. Withaferin A, a natural steroidal lactone derived from Physalis minima, exhibits potential biological activity and holds promise as a therapeutic agent. [...] Read more.

The development of advanced high-capacity nanoparticle-based drug loading, precise targeting, low toxicity, and excellent biocompatibility is critical for improving cancer therapeutics. Withaferin A, a natural steroidal lactone derived from Physalis minima, exhibits potential biological activity and holds promise as a therapeutic agent. In this study, a novel nanoconjugate (NC) was developed using gold nanoparticles (AuNPs) functionalized with polyvinylpyrrolidone (PVP), Withaferin A drug, and folic acid for targeted drug delivery in cancer treatment. The AuNPs–PVP–Withaferin A–FA nanoconjugate was synthesized through a layer-by-layer assembly process and was confirmed using UV–visible and FTIR spectroscopy. The hydrodynamic radius, surface charge, and morphology of the NC were characterized using dynamic light scattering (DLS), zeta potential analysis, and electron microscopy, respectively. The nanoformulation demonstrated a pH-responsive drug release, with 92% of Withaferin A released at pH 5, mimicking the tumor microenvironment. In vitro cytotoxicity studies conducted on MCF-7 cells using MTT assays, dual dye staining, and protein expression analysis revealed that the nanoconjugate effectively induced apoptosis in cancer cells. These outcomes emphasize the prospect AuNPs–PVP–Withaferin A–FA nanoconjugate as a targeted and efficient Withaferin A delivery system for cancer therapy, leveraging the inherent anticancer properties of Withaferin A. Full article

(This article belongs to the Special Issue Composite Materials Processing, Modeling and Simulation)

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16 pages, 9250 KiB

Open AccessArticle

Numerical Investigation into Particle Migration Characteristics in Hydraulic Oil Filtration

by Jian Chen, Dongyang Xi, Guichao Wang, Mi Zhou, Yibo Hu and Xihua Xie

Processes 2025, 13(5), 1289; https://doi.org/10.3390/pr13051289 - 23 Apr 2025

Abstract

An oil filter is a necessary and significant part of many manufacturing processes and equipment. Unlike the structural design and filter material selection, the particle movement in the filter during filtration is the fundamental factor influencing the filter’s performance, but this has not [...] Read more.

An oil filter is a necessary and significant part of many manufacturing processes and equipment. Unlike the structural design and filter material selection, the particle movement in the filter during filtration is the fundamental factor influencing the filter’s performance, but this has not attracted enough attention. Due to the small size and large number of particles in the filter, it is difficult to monitor every particle’s movement. Therefore, this work used a hydraulic oil filter as a case study. Computational Fluid Dynamics (CFD) was coupled with the Discrete Phase Model (DPM) to investigate the particle motion in the filter. A filter boundary function was programmed to simulate the filter cartridge zone. The effects of inlet velocity and oil temperature/viscosity on the particle movement and filtration performance were studied. The results showed that a low-velocity zone existed and trapped some contaminant particles, particularly for particles with large Stokes numbers. The results also demonstrated that increased temperature induced an apparent reduction in filtering efficiency within the first 1.8 s from 0.61 to 0.49 when the temperature increased from 15 °C to 70 °C for 25 μm particles. Full article

(This article belongs to the Section Particle Processes)

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Graphical abstract

16 pages, 8377 KiB

Open AccessArticle

Stratigraphic Correlation of Well Logs Using Geology-Informed Deep Learning Networks

by Zhaohui Xu, Boyu Zheng, Bo Liu and Wendan Song

Processes 2025, 13(5), 1288; https://doi.org/10.3390/pr13051288 - 23 Apr 2025

Abstract

Stratigraphic correlation plays a crucial role in reservoir characterization. However, it is often time-consuming and heavily dependent on geological expertise. To address this issue, we propose a novel method called CMT-enhanced Hiformer, which integrates convolutional neural networks meet vision transformers (CMT) and hierarchical [...] Read more.

Stratigraphic correlation plays a crucial role in reservoir characterization. However, it is often time-consuming and heavily dependent on geological expertise. To address this issue, we propose a novel method called CMT-enhanced Hiformer, which integrates convolutional neural networks meet vision transformers (CMT) and hierarchical multi-scale representations using transformers (Hiformer). First, the architecture of CMT-enhanced Hiformer fuses the advantages of convolutional neural networks and transformers, effectively extracting complex features from well logs and capturing both local and global dependencies via a well-designed attention mechanism. Next, a geological constraint with regularization parameters is incorporated into the loss function. The new loss function promotes the accuracy of stratigraphic boundaries. The proposed method was validated using data from the Shuanghe oil field in central China. Specifically, the model achieved a maximum F1 score of 0.8857 and a precision of 0.8865 on the blind test dataset, demonstrating its robustness and high classification accuracy. Moreover, we conducted ablation studies and performed a detailed comparison with state-of-the-art deep learning models. The results demonstrate that the proposed method significantly improves the accuracy and efficiency of stratigraphic correlation. Full article

(This article belongs to the Special Issue Applications of Intelligent Models in the Petroleum Industry)

20 pages, 1638 KiB

Open AccessArticle

Brake Disc Material Selection Based on MCDM and Simulation

by Javier Martínez-Gómez and Juan Francisco Nicolalde

Processes 2025, 13(5), 1287; https://doi.org/10.3390/pr13051287 - 23 Apr 2025

Abstract

Material selection is a crucial aspect of product design, often determining the success or failure of a product in the market. It involves an exploration of the main criteria for the application of the product, according to the properties required by the component [...] Read more.

Material selection is a crucial aspect of product design, often determining the success or failure of a product in the market. It involves an exploration of the main criteria for the application of the product, according to the properties required by the component to be designed. The present study aims to evaluate the material selection of a brake disc in light SUV-type vehicles. The material selection is based on multi-criteria decision making (MCDM) methods. Five different MCDM methods were used to select the best material alternatives and the ENTROPY method was used for weighting the criteria. In addition, a simulation is carried out to validate the results of the MCDM analysis and to show that the selected material can be used due to its strength and temperature conditions. Due to its low density, high yield strength, and good compressive strength, the best alternative is ASTM A536 material for three MCDM methods and the second option is ASTM A48 according to two methods. Full article

(This article belongs to the Special Issue Multi-Criteria Decision Making in Chemical and Process Engineering)

22 pages, 2714 KiB

Open AccessArticle

Seed Train Intensification and TFDF-Based Perfusion for MDCK Cell-Based Influenza A Virus Production

by Tilia Zinnecker, Emelie Wicke, Udo Reichl, Sven Göbel and Yvonne Genzel

Processes 2025, 13(5), 1286; https://doi.org/10.3390/pr13051286 - 23 Apr 2025

Abstract

The production of influenza A virus (IAV) using Madin-Darby Canine Kidney (MDCK) cells is a key strategy for efficient influenza vaccine manufacturing. However, challenges remain in optimizing cell culture processes for higher yield and efficiency. This study aims to evaluate different process intensification [...] Read more.

The production of influenza A virus (IAV) using Madin-Darby Canine Kidney (MDCK) cells is a key strategy for efficient influenza vaccine manufacturing. However, challenges remain in optimizing cell culture processes for higher yield and efficiency. This study aims to evaluate different process intensification strategies on two distinct clonal MDCK suspension cell lines (C59 and C113) for improved IAV production. A semi-perfusion strategy was used to push cells towards high cell density (HCD), achieving up to 17 × 10⁶ C113 cells/mL and 42 × 10⁶ C59 cells/mL, respectively. Next, a Tangential Flow Depth Filtration (TFDF)-based perfusion process with direct harvest during IAV production was established, resulting in high titers and a 10-fold higher space-time yield for C59 and a 4-fold improvement for C113 compared to batch operation. In addition, the suitability of N-1 perfusion was evaluated for batch and intensified fed-batch processes. Cells taken from the N-1 perfusion showed different cell-specific growth rates, but this had no effect on virus titers except for processes started from oxygen-deprived precultures. Finally, comparable virus titers were obtained when the production bioreactor was directly inoculated from an HCD cryovial. Taken together, seed train intensification and TFDF-based perfusion majorly reduced process times and improved IAV production. Full article

(This article belongs to the Section Biological Processes and Systems)

23 pages, 1024 KiB

Open AccessArticle

Integrated Coordinated Control of Source–Grid–Load–Storage in Active Distribution Network with Electric Vehicle Integration

by Shunjiang Wang, Yiming Luo, Peng Yu and Ruijia Yu

Processes 2025, 13(5), 1285; https://doi.org/10.3390/pr13051285 - 23 Apr 2025

Abstract

In line with the strategic plan for emerging industries in China, renewable energy sources like wind power and photovoltaic power are experiencing vigorous growth, and the number of electric vehicles in use is on a continuous upward trend. Alongside the optimization of the [...] Read more.

In line with the strategic plan for emerging industries in China, renewable energy sources like wind power and photovoltaic power are experiencing vigorous growth, and the number of electric vehicles in use is on a continuous upward trend. Alongside the optimization of the distribution network structure and the extensive application of energy storage technology, the active distribution network has evolved into a more flexible and interactive “source–grid–load–storage” diversified structure. When electric vehicles are plugged into charging piles for charging and discharging, it inevitably exerts a significant impact on the control and operation of the power grid. Therefore, in the context of the extensive integration of electric vehicles, delving into the charging and discharging behaviors of electric vehicle clusters and integrating them into the optimization of the active distribution network holds great significance for ensuring the safe and economic operation of the power grid. This paper adopts the two-stage “constant-current and constant-voltage” charging mode, which has the least impact on battery life, and classifies the electric vehicle cluster into basic EV load and controllable EV load. The controllable EV load is regarded as a special “energy storage” resource, and a corresponding model is established to enable its participation in the coordinated control of the active distribution network. Based on the optimization and control of the output behaviors of gas turbines, flexible loads, energy storage, and electric vehicle clusters, this paper proposes a two-layer coordinated control model for the scheduling layer and network layer of the active distribution network and employs the improved multi-target beetle antennae search optimization algorithm (MTTA) in conjunction with the Cplex solver for solution. Through case analysis, the results demonstrate that the “source–grid–load–storage” coordinated control of the active distribution network can fully tap the potential of resources such as flexible loads on the “load” side, traditional energy storage, and controllable EV clusters; realize the economic operation of the active distribution network; reduce load and voltage fluctuations; and enhance power quality. Full article

(This article belongs to the Special Issue Analysis and Optimization Control of Active Distribution Networks and Smart Grids)

21 pages, 5088 KiB

Open AccessArticle

Doubly Fed Induction Generator Frequency Regulation Enhancement Using Combined Inertia and Proportional Resonant Controller

by Mohamed Abdeen, Saleh Al Dawsari, Mahmoud A. El-Dabah, Mamdouh K. Ahmed, Ezzeddine Touti, Ahmed A. Zaki Diab and Ayat G. Abo El-Magd

Processes 2025, 13(5), 1284; https://doi.org/10.3390/pr13051284 - 23 Apr 2025

Abstract

Power systems are currently undergoing a transition from centralized synchronous generators to decentralized non-synchronous generators that rely on renewable energy sources. This shift poses a challenge to system operators, as the high penetration levels of renewable energy introduce variability and changes in the [...] Read more.

Power systems are currently undergoing a transition from centralized synchronous generators to decentralized non-synchronous generators that rely on renewable energy sources. This shift poses a challenge to system operators, as the high penetration levels of renewable energy introduce variability and changes in the physics of power systems. Load-frequency control is one of the biggest challenges faced by electrical grids, especially with increased wind energy penetration in recent years. The inertial controller is one of the methods used to support system frequency in variable-speed wind turbines. In this study, a proportional resonant (PR) controller was added to an inertial controller to achieve better frequency regulation by controlling the active power of the doubly fed induction generator (DFIG). First, the impact of the PR controller parameters on the frequency deviation, overshoot, settling time, and system stability was investigated to identify the optimal values that achieved the lowest frequency deviation while maintaining system stability. Second, the performance of the proposed method was compared that of the traditional method under different load perturbations. The results prove that improperly determining the proportional gain of the PR controller negatively affects system stability and frequency deviation. In addition, the results validate the hypothesis that the proposed method would provide fast frequency support for all the studied cases. The analysis and simulation of these scenarios were performed using the MATLAB/SIMULINK program. Full article

(This article belongs to the Section Energy Systems)

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24 pages, 1114 KiB

Open AccessArticle

Actuator Fault Estimation for Distributed Interconnected Lipschitz Nonlinear Systems with Direct Feedthrough Inputs

by Ling Fang, Zhi-Wei Gao and Yuanhong Liu

Processes 2025, 13(5), 1283; https://doi.org/10.3390/pr13051283 - 23 Apr 2025

Abstract

Distributed interconnected systems are complex dynamic systems where every single subsystem has an impact on other subsystems. Actuators are key components in interconnected dynamic systems, which are prone to faults due to age and unexpected conditions. Therefore, there is motivation to develop an [...] Read more.

Distributed interconnected systems are complex dynamic systems where every single subsystem has an impact on other subsystems. Actuators are key components in interconnected dynamic systems, which are prone to faults due to age and unexpected conditions. Therefore, there is motivation to develop an effective diagnosis algorithm for distributed interconnected systems, which is a starting point for predictive maintenance. In this study, an actuator fault estimation approach is proposed for a class of nonlinear interconnected systems with direct feedthrough inputs. Specifically, the original interconnected system is transformed into an augmented system by setting an extended state vector composed of an original state vector and actuator fault vector. An additional control term is used to eliminate the impact from unknown disturbances on the estimator error dynamics. Regional pole constraints are considered in the design of the distributed robust observer so that the poles are placed into a desired stable region. The observer gains are obtained by solving simultaneous linear matrix inequalities. Finally, the effectiveness of the proposed method is demonstrated by simulation studies, and a comparison is also provided. Full article

(This article belongs to the Special Issue Model Based, Data Driven Identification and Control for Developing Intelligent and Smart Processes and Systems)

17 pages, 3339 KiB

Open AccessFeature PaperArticle

Case Study: Component Design for Streamlining the Manufacturing Process Using 3D Printing

by Jozef Trojan, Peter Trebuňa, Jozef Svetlík and Ján Kopec

Processes 2025, 13(5), 1282; https://doi.org/10.3390/pr13051282 - 23 Apr 2025

Abstract

The innovative pressure device, developed to address contamination issues on Essity Slovakia’s carton production line, was successfully implemented using 3D printing technology. This approach resulted in a precise prototype that significantly reduces contamination, simplifies packaging procedures, and lessens the need for manual labor. [...] Read more.

The innovative pressure device, developed to address contamination issues on Essity Slovakia’s carton production line, was successfully implemented using 3D printing technology. This approach resulted in a precise prototype that significantly reduces contamination, simplifies packaging procedures, and lessens the need for manual labor. The project entailed a comprehensive review of the current system, 3D scanning, creation of a model using SolidWorks software, and fabrication with a Trilab DeltiQ 2 printer. The outcomes demonstrate a staggering 96% decrease in contamination, elimination of downtime, and a boost in overall line efficiency. This research underscores the transformative capabilities of additive manufacturing in industrial modernization and accentuates the significance of technological advancements in enhancing efficiency, sustainability, and quality within the manufacturing industry. Full article

(This article belongs to the Special Issue Circular Economy on Production Processes and Systems Engineering)

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13 pages, 4638 KiB

Open AccessArticle

Migration and Conversion of Al Element in the Hydrometallurgical Preparation of Al₂O₃ from Secondary Aluminium Dross

by Kepeng Huang, Changjiang Zheng, Qingda Li, Xinyang Qiu and Xuemei Yi

Processes 2025, 13(5), 1281; https://doi.org/10.3390/pr13051281 - 23 Apr 2025

Abstract

The amount of secondary aluminium dross in China exceeds one million tons annually, posing environmental and disposal challenges. This study explores acid leaching as an alternative to conventional alkali methods for recovering Al from secondary aluminium dross to produce Al₂O₃ [...] Read more.

The amount of secondary aluminium dross in China exceeds one million tons annually, posing environmental and disposal challenges. This study explores acid leaching as an alternative to conventional alkali methods for recovering Al from secondary aluminium dross to produce Al₂O₃. Research has focused on optimizing leaching conditions. Under optimized H₂SO₄ leaching conditions, an Al³⁺ leaching ratio of 86.5% is achieved. By maintaining a pH below 9 during hydrolytic precipitation and multiple washes, the leaching efficiency of Al from Al(OH)₃ reached 95.97%. The original dross, which is primarily composed of Al, Al₂O₃, and AlN, undergoes a transformation where AlN becomes Al(OH)₃ during washing. Thermal decomposition then yields Al₂O₃. The overall recovery of Al reaches 83.11%. Full article

(This article belongs to the Special Issue Recent Trends in Extractive Metallurgy)

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2 pages, 139 KiB

Open AccessCorrection

Correction: Supramani et al. Performance of Biomass and Exopolysaccharide Production from the Medicinal Mushroom Ganoderma lucidum in a New Fabricated Air-L-Shaped Bioreactor (ALSB). Processes 2023, 11, 670

by Sugenendran Supramani, Nur Ardiyana Rejab, Zul Ilham, Rahayu Ahmad, Pau-Loke Show, Mohamad Faizal Ibrahim and Wan Abd Al Qadr Imad Wan-Mohtar

Processes 2025, 13(5), 1280; https://doi.org/10.3390/pr13051280 - 23 Apr 2025

Abstract

Error in Table [...] Full article

(This article belongs to the Section Biological Processes and Systems)

12 pages, 3340 KiB

Open AccessArticle

Enhancing the Quality and Sustainability of Laser Cutting Processes in Laser-Assisted Manufacturing Using a Box–Behnken Design

by Omid Mehrabi, Zeinab Malekshahi Beiranvand, Fakhir A. Rasoul and Mahmoud Moradi

Processes 2025, 13(5), 1279; https://doi.org/10.3390/pr13051279 - 23 Apr 2025

Abstract

This study aims to examine and optimize CO₂ laser cutting parameters—namely, laser power, cutting speed, and focal plane position—when applied to polypropylene material using an experimental methodology. This research aims to improve cutting quality, increase cutting speed, and reduce waste while adhering [...] Read more.

This study aims to examine and optimize CO₂ laser cutting parameters—namely, laser power, cutting speed, and focal plane position—when applied to polypropylene material using an experimental methodology. This research aims to improve cutting quality, increase cutting speed, and reduce waste while adhering to sustainability objectives. To achieve these goals, a comprehensive experimental approach was employed, incorporating the Box–Behnken Design (BBD) based on the response surface methodology (RSM) to optimize the laser cutting process by evaluating the relationships between input parameters and output responses. Data were collected through a series of controlled experiments in which laser power (ranging from 30 to 60 W), cutting speed (ranging from 30 to 60 mm/s), and focal plane position (set at −3, 0, and +3 mm) were systematically varied. The responses, quantified regarding cut quality, include kerf width and the heat-affected zone (HAZ). Additionally, RSM was used to optimize the laser cutting process to improve kerf quality. The results indicated that cutting speed has an inverse effect on kerf width and HAZ, while laser power has a direct effect. Furthermore, the focal plane position was found to have the least impact on the output responses. The maximum kerf width and HAZ were observed at a minimum cutting speed of 30 mm/s and a maximum laser power of 60 W. Full article

(This article belongs to the Special Issue Progress in Laser-Assisted Manufacturing and Materials Processing)

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28 pages, 1129 KiB

Open AccessReview

Metal-Based Nanoparticles as Nanopesticides: Opportunities and Challenges for Sustainable Crop Protection

by Puji Shandila, Tunjung Mahatmanto and Jue-Liang Hsu

Processes 2025, 13(5), 1278; https://doi.org/10.3390/pr13051278 - 23 Apr 2025

Abstract

Metal-based nanoparticles (MNPs) are gaining attention as promising components of nanopesticides, offering innovative solutions to enhance agricultural pest management while addressing environmental concerns associated with traditional pesticides. MNPs, such as silver, copper, zinc, nickel, gold, iron, aluminum, and titanium, exhibit unique nanoscale properties. [...] Read more.

Metal-based nanoparticles (MNPs) are gaining attention as promising components of nanopesticides, offering innovative solutions to enhance agricultural pest management while addressing environmental concerns associated with traditional pesticides. MNPs, such as silver, copper, zinc, nickel, gold, iron, aluminum, and titanium, exhibit unique nanoscale properties. These properties enable the formulation of MNPs for controlled and sustained release, thereby reducing application frequency and minimizing environmental runoff. This controlled release mechanism not only improves pest management efficacy but also reduces risks to non-target organisms and beneficial species, aligning with the principles of sustainable crop protection. This review examines nanopesticides based on their specific targets, such as nanoinsecticide, nanobactericide, nanofungicide, nanonematicide, and nanoviricide. It also explores the mechanisms of action of metal-based nanoparticles, including physical disruption, chemical interactions, and biological processes. Additionally, the review details how MNPs compromise cellular integrity through mechanisms such as membrane damage, DNA disruption, mitochondrial impairment, and protein denaturation. Despite these advantages, significant challenges remain, particularly concerning the environmental impact of MNPs, their long-term effects on soil health and ecosystem dynamics, and potential risks to human safety. Addressing these challenges is crucial for realizing the full potential of MNPs in sustainable agriculture. Full article

(This article belongs to the Special Issue Feature Review Papers in Section "Environmental and Green Processes")

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18 pages, 6611 KiB

Open AccessArticle

Optimization of Thiourea-Promoted Gold and Silver Leaching from Pyrite Cinders Using Response Surface Methodology (RSM)

by Yerkezhan Abikak, Bagdaulet Kenzhaliev, Ata Akcil, Seydou Dembele, Aigul Koizhanova, Nauryzbek Bakhytuly and Gulzhaina Kassymova

Processes 2025, 13(5), 1277; https://doi.org/10.3390/pr13051277 - 22 Apr 2025

Abstract

The cyanidation of precious metals from ores and secondary resources has been classified as a hazardous process due to the release of toxic gases. The use of environmentally friendly and cost-effective processes is a suitable alternative to cyanidation. Thiourea leaching has been shown [...] Read more.

The cyanidation of precious metals from ores and secondary resources has been classified as a hazardous process due to the release of toxic gases. The use of environmentally friendly and cost-effective processes is a suitable alternative to cyanidation. Thiourea leaching has been shown to be one of the best alternative reagents to cyanide. The present work aims to evaluate the efficiency of the thiourea leaching of gold and silver from pretreated pyrite cinders. The use of pre-chemical activation prior to leaching helped to increase the amount of free gold and silver particles. A preliminary leaching test led to the selection of Fe₂(SO₄)₃ as a suitable oxidizing agent for Au and Ag leaching. To select suitable leaching parameters, the response surface methodology (RSM) was used to optimize some parameters that can considerably affect sulfuric acid–thiourea leaching and identify the greatest interaction between them. The optimized parameters of 30 g/L thiourea, 10% pulp density, pH = 1, and 50 °C over 4 h of leaching time allowed for Au and Ag recoveries of 98.31 and 88.57%, respectively. Full article

(This article belongs to the Special Issue Chemical Systems Dynamic Modeling and Simulation)

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14 pages, 1450 KiB

Open AccessArticle

Investigation of the Process of Increasing Bismuth Content in Lead Alloys Using the Oxygen Oxidation Method

by Aibar S. Kizatov, Yernat A. Kozhakhmetov, Natalya A. Kulenova and Raigul A. Ramazanova

Processes 2025, 13(5), 1276; https://doi.org/10.3390/pr13051276 - 22 Apr 2025

Abstract

Bismuth is a promising and environmentally safe metal widely used in various industries, including electronics, medicine and metallurgy. Despite this, its production is associated with a number of technological difficulties due to the low content of bismuth in natural ores and its presence [...] Read more.

Bismuth is a promising and environmentally safe metal widely used in various industries, including electronics, medicine and metallurgy. Despite this, its production is associated with a number of technological difficulties due to the low content of bismuth in natural ores and its presence mainly as a by-product of lead processing. The present article is devoted to the study of the method of increasing the content of bismuth in lead alloys using oxygen oxidation. It is shown that lead, which has a high affinity for oxygen, is effectively oxidized and passes into the slag phase, whereas bismuth is concentrated in the metallic phase. Experiments were carried out at 650 °C using boric acid to lower the melting point of the slag and improve its flowability. As a result of five enrichment steps, the bismuth content in the alloy increased from 4.0% to 48.8%. The proposed method demonstrates high selectivity and economic efficiency, which makes it promising for industrial application. The results of the study can be used to develop more environmentally safe and energy-efficient technologies for bismuth lead enrichment, which is especially relevant in the context of growing demand for bismuth in various industries. Full article

(This article belongs to the Section Manufacturing Processes and Systems)

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15 pages, 6887 KiB

Open AccessArticle

SCA Fracturing Mechanisms of Rock Mass and Application in Overhanging Roof Structure Fragmentation of Mine Goaf

by Hui Li, Ruifu Yuan, Penghui Zai, Qunlei Zhang and Chun Feng

Processes 2025, 13(5), 1275; https://doi.org/10.3390/pr13051275 - 22 Apr 2025

Abstract

During coal resource mining, hard roof mining is prone to causing rock-burst disasters because traditional blasting–cutting roof technology has the disadvantages of low efficiency and high cost. This article studies the theoretical basis and engineering application of fracturing technology with a static expansion [...] Read more.

During coal resource mining, hard roof mining is prone to causing rock-burst disasters because traditional blasting–cutting roof technology has the disadvantages of low efficiency and high cost. This article studies the theoretical basis and engineering application of fracturing technology with a static expansion agent (SCA). The influences of borehole diameter and spacing on the fracturing effect of a rock mass are studied through theoretical analysis and simulation. Rock mass models of a cantilever beam for a single rock layer and multiple layers were established, and the mechanical properties of the roof strata under three working conditions were analyzed. The research results show that the maximum annular stress value occurs along the drill hole wall between the adjacent drill holes, and the annular stress at the center line between two drill holes is the smallest. As the spacing between the holes increases, the annular stress at the center line decreases; however, the annular stress at the center of the drill line becomes larger with the increase in hole diameter. The degree of stress concentration increases sharply with the decrease in distance f from the borehole center to the free surface. Relative to the cantilever beam model of a single rock layer, the combined rock layers can effectively control the displacement and deformation of the cantilever roof. Based on the above research results, a drilling method with a 75 mm diameter and a 10° inclination angle is used, demonstrating that the suspended roof area can be reduced to below 20 m² using the fracturing technology with a static expansion agent, allowing the roof strata to fall simultaneously during mining. Full article

(This article belongs to the Section Energy Systems)

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19 pages, 8687 KiB

Open AccessArticle

Research on the Effect of Damping Grooves on the Pressure and Cavitation Characteristics of Axial Piston Pumps

by Ruichuan Li, Dongrun Li, Zhengyu Li, Tong Wu and Jikang Xu

Processes 2025, 13(5), 1274; https://doi.org/10.3390/pr13051274 - 22 Apr 2025

Abstract

The damping groove structure of the port plate plays a crucial role in the pulsation suppression, vibration reduction, and noise optimization of the piston pump. Different damping groove structures have a significant impact on the flow distribution process during the normal operation of [...] Read more.

The damping groove structure of the port plate plays a crucial role in the pulsation suppression, vibration reduction, and noise optimization of the piston pump. Different damping groove structures have a significant impact on the flow distribution process during the normal operation of the port plate, affecting the pump outlet flow and pressure pulsations, which in turn influence the noise level of the piston pump. Therefore, the damping groove in the piston pump is one of the key structures influencing the pump’s pressure and cavitation behavior. To address the pressure shocks and oscillations caused by the distribution process in the piston pump, this study proposes a novel damping groove and performs CFD simulations on the non-damped groove. The analysis focuses on the pressure pulsation characteristics in the plunger chamber and the cavitation behavior of the pump. Additionally, an optimization analysis of the structural parameters of the new damping groove is conducted, which effectively reduces pressure shocks and cavitation in the swash plate axial piston pump. This study provides a theoretical foundation for improving the performance and lifespan of piston pumps. Full article

(This article belongs to the Special Issue Application of Refrigeration and Heat Pump Technology)

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14 pages, 2843 KiB

Open AccessArticle

Thermodynamic Analysis of a Compact System Generating Hydrogen for Mobile Fuel Cell Applications

by Qiaolin Lang, Xiaobo Yang, Ke Liang, Yang Liu and Yang Zhang

Processes 2025, 13(5), 1273; https://doi.org/10.3390/pr13051273 - 22 Apr 2025

Abstract

A thermodynamic analysis of a compact hydrogen generation system for mobile fuel cell applications is presented. The system consists of a miniature autothermal steam reformer (ATR) and a water–gas shift (WGS) reactor, designed to produce hydrogen from hydrocarbon fuels for a 1 kW [...] Read more.

A thermodynamic analysis of a compact hydrogen generation system for mobile fuel cell applications is presented. The system consists of a miniature autothermal steam reformer (ATR) and a water–gas shift (WGS) reactor, designed to produce hydrogen from hydrocarbon fuels for a 1 kW proton exchange membrane (PEM) fuel cell. Methane is used as the model fuel, and the study focuses on optimizing feed compositions and operational conditions to maximize hydrogen yield and purity. Feed compositions and operational conditions are optimized. In total, 0.7 Nm³ h⁻¹ H₂ is generated from 0.25 Nm³ h⁻¹ CH₄ with properly adjusted steam and air feeding. Issues with product purity and start-up procedures have been identified and discussed, along with feasible solutions. The system is suitable for remote and mobile applications. Full article

(This article belongs to the Special Issue Studies on Chemical Processes Thermodynamics)

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34 pages, 1406 KiB

Open AccessReview

Electrochemical-Based Technologies for Removing NSAIDs from Wastewater: Systematic Review with Bibliometric Analysis

by Katarina D. Stojanović, Danka D. Aćimović and Tanja P. Brdarić

Processes 2025, 13(5), 1272; https://doi.org/10.3390/pr13051272 - 22 Apr 2025

Abstract

Electrochemical-based processes have shown great promise in removing organic pollutants such as non-steroidal anti-inflammatory drugs (NSAIDs) from wastewater due to their effectiveness in addressing environmental pollution. This study conducts a bibliometric analysis of the most-cited articles in the field to systematically evaluate the [...] Read more.

Electrochemical-based processes have shown great promise in removing organic pollutants such as non-steroidal anti-inflammatory drugs (NSAIDs) from wastewater due to their effectiveness in addressing environmental pollution. This study conducts a bibliometric analysis of the most-cited articles in the field to systematically evaluate the progress and current state of electrochemical methods for NSAID removal from wastewater. Additionally, it highlights the potential of combining electrochemical techniques with other treatment methods to enhance the overall efficiency of NSAID removal. Research in this field has mainly focused on three technologies: electro-peroxone process (E-peroxone), electro-Fenton (EF), and electrochemical oxidation (EO). Early studies prioritized EO-based treatments, but interest has gradually shifted toward EF and E-peroxone. Future research is expected to focus on the development of cost-effective electrode materials, improving energy efficiency, and exploring hybrid systems for more effective treatment of wastewater contaminated with NSAIDs. An integrated bibliometric and systematic review framework presented in this study provides the first comprehensive assessment of electrochemical strategies for NSAIDs removal, highlighting the evolution of research focus and the potential of hybrid approaches. Full article

(This article belongs to the Special Issue Municipal Wastewater Treatment and Removal of Micropollutants)

18 pages, 1609 KiB

Open AccessArticle

Effect of Applied Voltages on Corn Stover Biomethanation and Microbial Community Characteristics in a Microbial Electrolytic Cell-Assisted Anaerobic Digestion System

by Qing Zhao, Hairong Yuan and Xiujin Li

Processes 2025, 13(5), 1271; https://doi.org/10.3390/pr13051271 - 22 Apr 2025

Abstract

This study aims to investigate the effect of different applied voltages on the biomethanation performance and microbial community characteristics of corn stover (CS) in a microbial electrolysis cell (MEC)-assisted anaerobic digestion (AD) system (MEC-AD). The results showed that the MEC-AD system operating at [...] Read more.

This study aims to investigate the effect of different applied voltages on the biomethanation performance and microbial community characteristics of corn stover (CS) in a microbial electrolysis cell (MEC)-assisted anaerobic digestion (AD) system (MEC-AD). The results showed that the MEC-AD system operating at 0.8 V achieved the highest methane yield of 192.40 mL CH₄/g VS (volatile solids), an increase of 14.98% compared to the conventional AD. The system obtained methane yields of 187.74 to 191.18 mL CH₄/g VS at lower voltages (0.4 V and 0.6 V), and 156.11–182.75 mL CH₄/g VS at higher voltages (1.0 V and 1.2 V), respectively, suggesting that lower or higher voltages would have adversely impacted the methane yield. Correspondingly, the MEC-AD system operating at 0.4–0.8 V achieved over 71.47% conversion rates of total solids (TS), VS, and cellulose. The microbial community analysis revealed that 0.8 V optimally enriched fermentative acidogenic bacteria (FABs, 24.55%) and electroactive bacteria (13.50%), enhancing both hydrolysis acidification efficiency and direct interspecies electron transfer (DIET). Both Methanosarcina and Methanoculleus demonstrated significant positive correlations with FABs, SOBs, and electroactive bacteria. This study reveals that 0.8 V represents the optimal operating voltage for biomethane production in MEC-AD systems, providing critical insights for agricultural waste valorization. Full article

(This article belongs to the Section Chemical Processes and Systems)

65 pages, 3461 KiB

Open AccessReview

Pharmaceutical Contamination by Biofilms Formed of the Burkholderia cepacia Complex: Public Health Risks

by Giorgio Silva-Santana, Francisca Letícia Sousa Sales, Alícia Ribeiro Aguiar and Marcelo Luiz Lima Brandão

Processes 2025, 13(5), 1270; https://doi.org/10.3390/pr13051270 - 22 Apr 2025

Abstract

Biofilms formation by the Burkholderia cepacia complex (Bcc) poses a considerable risk to hospital environments, particularly for immunocompromised individuals. These bacteria exhibit notable resistance to disinfectants and antibiotics, mainly due to their ability to adhere to biotic and abiotic surfaces, forming highly persistent [...] Read more.

Biofilms formation by the Burkholderia cepacia complex (Bcc) poses a considerable risk to hospital environments, particularly for immunocompromised individuals. These bacteria exhibit notable resistance to disinfectants and antibiotics, mainly due to their ability to adhere to biotic and abiotic surfaces, forming highly persistent biofilms, contamination, and pharmaceutical solutions. These microbial structures function as protective shields, impeding the effective action of antimicrobial compounds and facilitating the occurrence of chronic infections and outbreaks in healthcare settings. The high genetic plasticity of the Bcc, evidenced by the presence of multiple chromosomes and the ease of horizontal gene transfer, further enhances its capacity for adaptation and treatment resistance. Moreover, the ability of the Bcc to survive in aquatic environments and withstand unfavorable conditions heightens concerns regarding the contamination of pharmaceutical products. This study examines the molecular mechanisms underlying Bcc biofilm formation, its impact on hospital infections, and the challenges associated with its eradication. It also discusses the current detection techniques available and innovative approaches to mitigating contamination in pharmaceutical products. In summary, a thorough understanding of the mechanisms underlying Bcc biofilm formation and maintenance is crucial for implementing more effective preventive measures and minimizing the risks associated with hospital infections. Full article

(This article belongs to the Special Issue Microbial Biofilms: Latest Advances and Prospects)

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22 pages, 6350 KiB

Open AccessArticle

Applications for Predicting Cracking Outlet Temperatures for Ethylene Cracker Furnaces Based on the GAC-BiLSTM-AM Method

by Yanwei Dong, Qirui Li, Delong Cui, Zhiping Peng, Jieguang He and Zhusen Liang

Processes 2025, 13(5), 1269; https://doi.org/10.3390/pr13051269 - 22 Apr 2025

Abstract

In order to achieve a good generalization ability across different prediction tasks and ensure the reliability of prediction results, this paper proposes a GAC-BiLSTM-AM prediction method based on ensemble learning. This method employs a dual-channel convolutional neural network to comprehensively extract and integrate [...] Read more.

In order to achieve a good generalization ability across different prediction tasks and ensure the reliability of prediction results, this paper proposes a GAC-BiLSTM-AM prediction method based on ensemble learning. This method employs a dual-channel convolutional neural network to comprehensively extract and integrate sample features, which are then input into a composite analysis module consisting of a bidirectional long short-term memory, an attention mechanism, and a fully connected layer to achieve in-depth analysis and processing of information, jointly constructing an efficient base learner. Meanwhile, during the parameter iteration tuning process of the base learner, a mistake correction mechanism is introduced to dynamically adjust sample weights in order to correct potential attention biases, and further combined with the gold rush optimizer to optimize the key structural parameters of the model. The application evaluation in multiple benchmark prediction tasks confirms that the GAC-BiLSTM-AM method possesses excellent generalization performance. Full article

(This article belongs to the Section Chemical Processes and Systems)

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14 pages, 5362 KiB

Open AccessCommunication

Comparison of Colour Measurement Methods in the Food Industry

by Hanna Boruczkowska, Tomasz Boruczkowski, Monika Bronkowska, Maja Prajzner and Elżbieta Rytel

Processes 2025, 13(5), 1268; https://doi.org/10.3390/pr13051268 - 22 Apr 2025

Abstract

Colour is a key parameter in the evaluation of food products. Accurate colour measurement enables us to maintain their consistent quality. The aim of this study was to compare three colour measurement methods. The food products used for the study were French fries, [...] Read more.

Colour is a key parameter in the evaluation of food products. Accurate colour measurement enables us to maintain their consistent quality. The aim of this study was to compare three colour measurement methods. The food products used for the study were French fries, the colour of which was checked after defined frying times. Their colour was measured using a professional Minolta C-5 spectrophotometer (Konica Minolta Sensing Europe B.V., Nieuwegein, The Netherlands) as well as a low-cost SparkFun SEN-15050 spectrophotometer (SparkFun Electronics, Niwot, CO, USA) and a readily available HP SkanJet 4850 scanner (Hewlett Packard, Palo Alto, CA, USA). The images obtained were analysed using free ImageJ software ver. 1.54. The results indicate that low-cost spectrophotometers used in the Internet of Things (IoT) systems and colour measurement methods based on vision techniques are suitable for less precise but fast measurements and, in such cases, can successfully replace the expensive and often bulky devices. Full article

(This article belongs to the Section Food Process Engineering)

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19 pages, 7720 KiB

Open AccessArticle

A Novel Fe(III)-Complex with 1,10-Phenanthroline and Succinate Ligands: Structure, Intermolecular Interactions, and Spectroscopic and Thermal Properties for Engineering Applications

by Danilo Gualberto Zavarize, João G. de Oliveira Neto, Kamila Rodrigues Abreu, Alejandro Pedro Ayala, Francisco Ferreira de Sousa and Adenilson Oliveira dos Santos

Processes 2025, 13(5), 1267; https://doi.org/10.3390/pr13051267 - 22 Apr 2025

Abstract

A new complex, tetrakis(1,10-phenanthroline)-bis(succinate)-(µ₂-oxo)-bis(iron(III)) nonahydrate, [Fe₂(Phen)₄(Succinate)₂(μ-O)](H₂O)₉, was synthesized using the slow evaporation method. This study provides a comprehensive characterization of this coordination compound, focusing on its structural, spectroscopic, and thermal properties, which are [...] Read more.

A new complex, tetrakis(1,10-phenanthroline)-bis(succinate)-(µ₂-oxo)-bis(iron(III)) nonahydrate, [Fe₂(Phen)₄(Succinate)₂(μ-O)](H₂O)₉, was synthesized using the slow evaporation method. This study provides a comprehensive characterization of this coordination compound, focusing on its structural, spectroscopic, and thermal properties, which are relevant for applications in catalysis, material science, and chemical engineering processes. Single-crystal X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared (FT-IR), ultraviolet-visible (UV-Vis) spectroscopy, and thermoanalytical analyses were employed to investigate the material properties. Intermolecular interactions were further explored through Hirshfeld surface analysis. XRD results revealed a monoclinic crystal system with the C2/c space group, lattice parameters: a = 12.7772(10) Å, b = 23.0786(15) Å, c = 18.9982(13) Å, β = 93.047(2)°, V = 5594.27(7) Å³, and four formulas per unit cell (Z = 4). The crystal packing is stabilized by C–H⋯O, C–O⋯H, C–H⋯π, and π⋯π intermolecular interactions, as confirmed by vibrational spectroscopy. The heteroleptic coordination environment, combining weak- and strong-field ligands, results in a low-spin state with an estimated crystal field stabilization energy of −4.73 eV. Electronic properties indicate direct allowed transitions (γ = 2) with a maximum optical band gap of 2.66 eV, suggesting potential applications in optoelectronics and photochemical processes. Thermal analysis demonstrated good stability within the 25–136 °C range, with three main stages of thermal decomposition, highlighting its potential for use in high-temperature processes. These findings contribute to the understanding of Fe(III)-based complexes and their prospects in advanced material design, catalytic systems, and process optimization. Full article

(This article belongs to the Special Issue Transport and Energy Conversion at the Nanoscale and Molecular Scale)

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19 pages, 707 KiB

Open AccessFeature PaperArticle

Nonlinear Back-Calculation Anti-Windup Based on Operator Theory

by Yuuki Morohoshi and Mingcong Deng

Processes 2025, 13(5), 1266; https://doi.org/10.3390/pr13051266 - 22 Apr 2025

Abstract

Real-world plants have various nonlinear characteristics such as friction and hysteresis, so nonlinear control is essential for precise control. In addition, actuators of plants have input constraints, which cause the integrator of the controller to windup. So far, anti-windup methods have mainly been [...] Read more.

Real-world plants have various nonlinear characteristics such as friction and hysteresis, so nonlinear control is essential for precise control. In addition, actuators of plants have input constraints, which cause the integrator of the controller to windup. So far, anti-windup methods have mainly been for linear controllers, and research on nonlinear controllers has not been sufficient. This paper proposes a back-calculation anti-windup method for nonlinear controllers. By analyzing and extending the back-calculation anti-windup for a Proportional–Integral controller using operator theory, it can be applied to nonlinear controllers. The proposed method is applied to integral sliding mode control and right coprime factorization. In the simulation, we compared the proposed method with and without its application, as well as with conditional integration, and confirmed the effectiveness of the proposed method. In the future, it is necessary to extend the method to be applicable to more complex systems. This study has the potential to contribute to the practical application of nonlinear control. Full article

(This article belongs to the Special Issue Advances in the Control of Complex Dynamic Systems)

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11 pages, 5065 KiB

Open AccessArticle

The Effect of Water–Rock Interaction on Shale Reservoir Damage and Pore Expansion

by Jin Pang, Tongtong Wu, Xinan Yu, Chunxi Zhou, Haotian Chen and Jiaao Gao

Processes 2025, 13(5), 1265; https://doi.org/10.3390/pr13051265 - 22 Apr 2025

Abstract

This study investigates the microscopic structural changes and the evolution of physical properties in typical shale samples from three wells in southwestern China during water–rock interactions. Using scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and other techniques, we analyzed the changes in [...] Read more.

This study investigates the microscopic structural changes and the evolution of physical properties in typical shale samples from three wells in southwestern China during water–rock interactions. Using scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and other techniques, we analyzed the changes in pore structure, mineral dissolution behavior, and fracture propagation in shale samples of different types (organic-rich, mixed, and inorganic) during water immersion. The results show that water–rock interaction significantly affects the porosity, fracture width, and physical properties of shale. As the reaction time increases, the pore volume and number of pores generally increase in all shale types, with significant fracture propagation. Furthermore, fracture width changes exhibit varying trends depending on the reaction depth. NMR T2 spectrum analysis indicates that water–rock interaction not only influences the expansion of microfractures but also shows different responses in organic and inorganic pores. SEM images further reveal the impact of water–rock interaction on mineral dissolution, particularly during the early stages, where the dissolution of minerals significantly alters the pore structure. Overall, water–rock interaction plays a crucial role in the development of shale gas reservoirs, providing valuable data and theoretical support for future shale gas extraction. Full article

(This article belongs to the Section Energy Systems)

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25 pages, 2048 KiB

Open AccessReview

Integration of Emerging and Conventional Technologies for Obtaining By-Products from Cocoa Pod Husk and Their Application

by Alejandra Bugarin, Angela Iquise, Bianca Motta Dolianitis, Marcus Vinícius Tres, Giovani Leone Zabot and Luis Olivera-Montenegro

Processes 2025, 13(5), 1264; https://doi.org/10.3390/pr13051264 - 22 Apr 2025

Abstract

This review discusses the potential of emerging technologies, as well as their integration with conventional methods, to optimize the extraction of lignocellulosic compounds from cocoa pod hull (CPH), an agro-industrial residue that represents approximately 76% of the total weight of the fruit. CPH [...] Read more.

This review discusses the potential of emerging technologies, as well as their integration with conventional methods, to optimize the extraction of lignocellulosic compounds from cocoa pod hull (CPH), an agro-industrial residue that represents approximately 76% of the total weight of the fruit. CPH is primarily composed of cellulose, hemicellulose, lignin, and pectin. Emerging technologies such as microwave-assisted extraction, hydrothermal treatment, subcritical water, ionic liquids, deep eutectic solvents, and ultrasound treatment have proven effective in recovering value-added compounds, especially when combined with conventional techniques to improve process efficiency. Furthermore, the use of technologies such as high-voltage electric discharge (HVED) is proposed to reduce inorganic contaminants, such as cadmium, ensuring the safety of by-products. The CPH compounds’ applications include use in the food, pharmaceutical, cosmetics, agricultural, biopolymer, and environmental industries. The conversion of CPH to biochar and biofuels via pyrolysis and supercritical extraction is also discussed. The integration of technologies presents an opportunity to valorize CPH and optimize by-product development; however, as research continues, process scalability and economic viability must be assessed. Full article

(This article belongs to the Special Issue The Recycling Process of Agro-Industrial Waste)

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18 pages, 1634 KiB

Open AccessArticle

Research on Photovoltaic Long-Term Power Prediction Model Based on Superposition Generalization Method

by Yun Chen, Jilei Liu, Bei Liu, Shipeng Liu and Dongdong Zhang

Processes 2025, 13(5), 1263; https://doi.org/10.3390/pr13051263 - 22 Apr 2025

Abstract

The integration of renewable energy sources, specifically photovoltaic generation, into the grid at a large scale has significantly heightened the volatility and unpredictability of the power system. Consequently, this presents formidable challenges to ensuring the reliable operation of the grid. This study introduces [...] Read more.

The integration of renewable energy sources, specifically photovoltaic generation, into the grid at a large scale has significantly heightened the volatility and unpredictability of the power system. Consequently, this presents formidable challenges to ensuring the reliable operation of the grid. This study introduces a novel stacked model for photovoltaic power prediction, integrating multiple conventional data processing methods as base learners, including Group Method of Data Handling (GMDH), Least Squares Support Vector Machine (LSSVM), Radial Basis Function Neural Network (RBFNN), and Emotional Neural Network (ENN). A Backpropagation Neural Network (BPNN) serves as the meta-learner, utilizing the outputs of the base learners as input features to enhance overall prediction accuracy by mitigating individual model errors. To assess the model’s effectiveness, five evaluation metrics are employed: Bayesian Information Criterion (BIC), Percent Mean Average Relative Error (PMARE), Legates and McCabe Index (LM), Mean Absolute Deviation (MAD), and Root Mean Square Error (RMSE), ensuring long-term stability in photovoltaic power output forecasting. Additionally, the model’s effectiveness and accuracy are validated using operational data from photovoltaic power plants in a particular province of China. The results indicate that the stacked model, after training, testing, and validation on multiple performance metrics, surpasses baseline single models in performance. Full article

(This article belongs to the Special Issue Advancements in Photovoltaic Technologies: Innovations for Enhanced Energy Conversion and Efficiency)

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Processes, Volume 13, Issue 5 (May 2025) – 32 articles

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