Processes

22 pages, 1274 KB

Open AccessArticle

Energy-Saving and Low-Emission Equipment Selection for Machining Process Based on New Quality Productivity Orientation

by Qin Xiang, Wenwen Ding and Shixiong Xing

Processes 2025, 13(11), 3437; https://doi.org/10.3390/pr13113437 (registering DOI) - 26 Oct 2025

The use of equipment is an important source of energy consumption and carbon emissions. The energy consumption and carbon emissions generated by different types and quantities of equipment processing the same product vary greatly. At present, most of the equipment selection is only [...] Read more.

The use of equipment is an important source of energy consumption and carbon emissions. The energy consumption and carbon emissions generated by different types and quantities of equipment processing the same product vary greatly. At present, most of the equipment selection is only a comparison of the best types, rarely considering the dynamic changes and effects of the production process elements, which makes it difficult to adapt to the needs of sustainable development. In order to solve this problem, we establish a production equipment selection model based on new quality productivity (NQP)-oriented, and establish a unified calculation method for different types of equipment to consider energy consumption and carbon emissions in the production process. The multi-objective egret swarm optimization algorithm (MESOA) is used to calculate the energy consumption and carbon emissions of different devices. A case was conducted, taking the shaft processing as an example. The results show that the optimal energy consumption and carbon emission of the same product produced by different equipment can be calculated under the orientation of new quality productivity. In the later stage of the algorithm, MESOA outperforms NSGA-2 by 5.3%. At last, this paper provides a positive result for equipment selection under the orientation of new quality production. Full article

(This article belongs to the Special Issue Processes in Industry 4.0/5.0: Automation, Robotics and Smart Manufacturing)

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11 pages, 3857 KB

Open AccessArticle

Study on the Fracture Characteristics and Mechanisms of Iron Ore Under Dynamic Loading

by Yilin Tian, Peng Xu, Hua Li, Junjie Li, Shiqing Zhou, Yanting Chen, Xuyang Chang and Zhibo Lin

Processes 2025, 13(11), 3436; https://doi.org/10.3390/pr13113436 (registering DOI) - 26 Oct 2025

Abstract

The dynamic fracture process of iron ore under blast loading is an important manifestation of ore fragmentation. To investigate the dynamic fracturing process of iron ore, Hopkinson bar experiments were conducted under different impact loads. The results indicate that under low strain rates, [...] Read more.

The dynamic fracture process of iron ore under blast loading is an important manifestation of ore fragmentation. To investigate the dynamic fracturing process of iron ore, Hopkinson bar experiments were conducted under different impact loads. The results indicate that under low strain rates, the dynamic stress–strain curve of iron ore exhibits compaction, elastic, and failure stages. However, as the strain rate increases, the compaction stage becomes less distinct, while the elastic modulus decreases and the failure strength increases, indicating the material toughness was enhanced at high strain rate. Moreover, under high strain rates, a significant increase in shear strain promotes the formation of tensile–shear cracks in the ore. In addition, based on the fragmentation of iron ore at different impact pressure, there exists a certain impact pressure, at which the proportion of large fragments decreases only slightly, while the amount of small fragments increases markedly. These findings provide important insights for optimizing fragmentation and improving blasting effectiveness. Full article

(This article belongs to the Special Issue Numerical Simulation and Engineering Application of Rock Mechanics and Geotechnical Engineering (Second Edition))

20 pages, 4410 KB

Open AccessArticle

Fractal Analysis of Microstructural Effects on Gas-Water Relative Permeability in Fractured Reservoirs

by Linhao Qiu, Yuxi Yang, Xiang Luo, Yunxiu Sai and Youyou Cheng

Processes 2025, 13(11), 3435; https://doi.org/10.3390/pr13113435 (registering DOI) - 26 Oct 2025

Abstract

During natural gas extraction, understanding multiphase flow in fractured reservoirs remains a critical challenge due to the heterogeneous distribution of pores and fractures and the multi-scale nature of seepage mechanisms. These complexities introduce randomness in fluid distribution and tortuosity in seepage channels, limiting [...] Read more.

During natural gas extraction, understanding multiphase flow in fractured reservoirs remains a critical challenge due to the heterogeneous distribution of pores and fractures and the multi-scale nature of seepage mechanisms. These complexities introduce randomness in fluid distribution and tortuosity in seepage channels, limiting accurate characterization of gas-water flow. To address this issue, a dual-medium gas-water two-phase relative permeability model is developed by incorporating the fractal dimension of fracture surfaces, the tortuosity of the rock matrix, and the stress sensitivity of fracture networks. The model integrates essential microstructural parameters to capture the nonlinear flow behavior in dual-porosity systems. A systematic sensitivity analysis is conducted to evaluate the effects of fracture and matrix properties on the relative permeability curve. Results indicate that the fracture surface fractal dimension exerts a dominant influence in the two-phase flow region (fracture fractal dimensions in the range of 1.6–2.8), while near single-phase flow, fracture fractal dimensions in the range of 2.4–2.8 strongly affect flow behavior. Overall, the findings demonstrate that fracture-related parameters play a greater role than matrix properties in governing permeability evolution. This study provides predictive capability for two-phase flow in stress-sensitive fractured carbonates. Full article

(This article belongs to the Special Issue Flow Mechanisms and Enhanced Oil Recovery)

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21 pages, 6893 KB

Open AccessArticle

A Multi-Source Data-Driven Fracturing Pressure Prediction Model

by Zhongwei Zhu, Mingqing Wan, Yanwei Sun, Xuan Gong, Biao Lei, Zheng Tang and Liangjie Mao

Processes 2025, 13(11), 3434; https://doi.org/10.3390/pr13113434 (registering DOI) - 26 Oct 2025

Abstract

Accurate prediction of fracturing pressure is critical for operational safety and fracturing efficiency in unconventional reservoirs. Traditional physics-based models and existing deep learning architectures often struggle to capture the intense fluctuations and complex temporal dependencies observed in actual fracturing operations. To address these [...] Read more.

Accurate prediction of fracturing pressure is critical for operational safety and fracturing efficiency in unconventional reservoirs. Traditional physics-based models and existing deep learning architectures often struggle to capture the intense fluctuations and complex temporal dependencies observed in actual fracturing operations. To address these challenges, this paper proposes a multi-source data-driven fracturing pressure prediction model, a model integrating TCN-BiLSTM-Attention Mechanism (Temporal Convolutional Network, Bidirectional Long Short-Term Memory, Attention Mechanism), and introduces a feature selection mechanism for fracture pressure prediction. This model employs TCN to extract multi-scale local fluctuation features, BiLSTM to capture long-term dependencies, and Attention to adaptively adjust feature weights. A two-stage feature selection strategy combining correlation analysis and ablation experiments effectively eliminates redundant features and enhances model robustness. Field data from the Sichuan Basin were used for model validation. Results demonstrate that our method significantly outperforms baseline models (LSTM, BiLSTM, and TCN-BiLSTM) in mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination (R²), particularly under high-fluctuation conditions. When integrated with slope reversal analysis, it achieves sand blockage warnings up to 41 s in advance, offering substantial potential for real-time decision support in fracturing operations. Full article

(This article belongs to the Special Issue Data-Based Prediction Models in Energy Systems: From Principles to Applications)

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22 pages, 2640 KB

Open AccessArticle

Mechanism-Guided and Attention-Enhanced Time-Series Model for Rate of Penetration Prediction in Deep and Ultra-Deep Wells

by Chongyuan Zhang, Chengkai Zhang, Ning Li, Chaochen Wang, Long Chen, Rui Zhang, Lin Zhu, Shanlin Ye, Qihao Li and Haotian Liu

Processes 2025, 13(11), 3433; https://doi.org/10.3390/pr13113433 (registering DOI) - 26 Oct 2025

Abstract

Accurate prediction of the rate of penetration (ROP) in deep and ultra-deep wells remains a major challenge due to complex downhole conditions and limited real-time data. To address the issues of physical inconsistency and weak generalization in conventional da-ta-driven approaches, this study proposes [...] Read more.

Accurate prediction of the rate of penetration (ROP) in deep and ultra-deep wells remains a major challenge due to complex downhole conditions and limited real-time data. To address the issues of physical inconsistency and weak generalization in conventional da-ta-driven approaches, this study proposes a mechanism-guided and attention-enhanced deep learning framework. In this framework, drilling physical principles such as energy balance are reformulated into differentiable constraint terms and directly incorporated in-to the loss function of deep neural networks, ensuring that model predictions strictly ad-here to drilling physics. Meanwhile, attention mechanisms are integrated to improve feature selection and temporal modeling: for tree-based models, we investigate their implicit attention to key parameters such as weight on bit (WOB) and torque; for sequential models, we design attention-enhanced architectures (e.g., LSTM and GRU) to capture long-term dependencies among drilling parameters. Validation on 49,284 samples from 11 deep and ultra-deep wells in China (depth range: 1226–8639 m) demonstrates that the synergy between mechanism constraints and attention mechanisms substantially improves ROP prediction accuracy. In blind-well tests, the proposed method achieves a mean absolute percentage error (MAPE) of 9.47% and an R² of 0.93, significantly outperforming traditional methods under complex deep-well conditions. This study provides reliable intelligent decision support for optimizing deep and ultra-deep well drilling operations. By improving prediction accuracy and enabling real-time anomaly detection, it enhances operational safety and efficiency while reducing drilling risks. The proposed approach offers high practical value for field applications and supports the intelligent development of the oil and gas industry. Full article

(This article belongs to the Section Energy Systems)

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14 pages, 2102 KB

Open AccessArticle

A Unified Control Strategy Integrating VSG and LVRT for Current-Source PMSGs

by Yang Yang, Zaijun Wu, Xiangjun Quan, Junjie Xiong, Zijing Wan and Zetao Wei

Processes 2025, 13(11), 3432; https://doi.org/10.3390/pr13113432 (registering DOI) - 25 Oct 2025

Abstract

The growing penetration of renewable energy has reduced system inertia and damping, threatening grid stability. This paper proposes a novel control strategy that seamlessly integrates virtual synchronous generator (VSG) emulation with low-voltage ride-through (LVRT) capability for direct-drive permanent magnet synchronous generators (PMSGs). The [...] Read more.

The growing penetration of renewable energy has reduced system inertia and damping, threatening grid stability. This paper proposes a novel control strategy that seamlessly integrates virtual synchronous generator (VSG) emulation with low-voltage ride-through (LVRT) capability for direct-drive permanent magnet synchronous generators (PMSGs). The unified control framework enables simultaneous inertia support during frequency disturbances and compliant reactive current injection during voltage sags—eliminating mode switching. Furthermore, the proposed strategy has been validated through both a single-machine model and actual wind farm topology. Results demonstrate that the strategy successfully achieves VSG control functionality while simultaneously meeting LVRT requirements. Full article

(This article belongs to the Special Issue Advances in Hydrogen Energy Systems Integration, Modeling and Optimization)

21 pages, 5340 KB

Open AccessArticle

A Study on the Basic Properties of Oil Shale and Its Oxidative Pyrolysis Kinetic Characteristics in an Air Atmosphere

by Zongyao Qi, Peng Liu, Tong Liu, Xiaokun Zhang, Changfeng Xi, Bojun Wang, Fang Zhao, Chuanju Zhao and Liang Zhang

Processes 2025, 13(11), 3431; https://doi.org/10.3390/pr13113431 (registering DOI) - 25 Oct 2025

Abstract

The in situ conversion of oil shale with air injection has the advantage of self-generated heat. The fragmentation degree of oil shale affects the oxidative pyrolysis process. In this paper, the basic properties of oil shale were analyzed, and weight loss observation and [...] Read more.

The in situ conversion of oil shale with air injection has the advantage of self-generated heat. The fragmentation degree of oil shale affects the oxidative pyrolysis process. In this paper, the basic properties of oil shale were analyzed, and weight loss observation and high-pressure TGA-DSC (thermogravimetric analysis and differential scanning calorimetry) tests in an air atmosphere were conducted using the cores and particles. The oil shale’s oxidative pyrolysis characteristics and the effect of its particle sizes were evaluated. The results show that the porosity and permeability conditions, TOC (total organic carbon), and inorganic mineral composition of oil shale are highly heterogeneous, with higher permeability and greater TOC along the bedding direction. The derivative of the TGA curve shows a single peak, and the heat flow curve shows a double peak that can be used to determine the oil shale’s oxidation type. The oxidative pyrolysis stage of organic matter can be divided into three temperature ranges, of which the medium temperature range is where the most combustion weight loss and heat release occurs. The activation energy of oxidative pyrolysis, which is affected by factors such as particle size, organic matter content, and pyrolysis temperature, is 46.92–248.11 kJ/mol, indicating the varying degrees of difficulty in initiating the reaction under different conditions. The pre-exponential factor is 3.15 × 10²–6.27 × 10¹¹ 1/s, and the enthalpy value is 2.575–4.045 kJ/g. The combustion indexes and reaction enthalpy under different particle sizes are more correlated with their own organic matter content. As oil shale particle size decreases, the variation law of the activation energy and pre-exponential factor changes with temperature from an initial continuous increase to a decrease, then increases again with the smallest kinetic parameters in the medium temperature zone. A small particle size, high organic matter content, and high pressure are more conducive to initiating the oxidative pyrolysis reaction to achieve in situ conversion of organic matter. Full article

(This article belongs to the Special Issue Oil Shale Mining and Processing)

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21 pages, 4515 KB

Open AccessArticle

Performance Evaluation of Hybrid and Conventional Coagulants for the Removal of Sunset Yellow and Methylene Violet Dyes from Wastewater

by Eftychia Kalli, Konstantinos N. Maroulas, Anna A. Thysiadou, George Z. Kyzas and Athanasia K. Tolkou

Processes 2025, 13(11), 3430; https://doi.org/10.3390/pr13113430 (registering DOI) - 25 Oct 2025

Abstract

Textile industries release dyes into wastewater, and when present above certain levels, these dyes pose serious risks because of their high toxicity. This study investigates the removal of Sunset Yellow (SY) and Methylene Violet (MV) dyes from wastewater using chitosan (CS) and polysilicate [...] Read more.

Textile industries release dyes into wastewater, and when present above certain levels, these dyes pose serious risks because of their high toxicity. This study investigates the removal of Sunset Yellow (SY) and Methylene Violet (MV) dyes from wastewater using chitosan (CS) and polysilicate acid (pSi) in the structure of aluminum-based coagulants, resulting in hybrid formulations (CS@Al, Al/pSi, and CS@Al/pSi). Among the various treatment methods that have been applied for the removal of dyes, the coagulation/flocculation process was chosen in the present study, as it is a cheap and effective method. Coagulation performance was optimized for pH, coagulant dosage, temperature and mixing time. The Al/pSi coagulant achieved nearly complete SY removal (98.8%) at 25 mg/L dosage and pH 3.0. MV removal in single-dye solutions was limited, with Al/pSi achieving only 26.6% removal at pH 3.0. However, in mixed-dye systems (SY/MV), synergistic interactions increased MV removal up to 94.4% and SY removal to 100%. Hybrid CS@Al/pSi showed lower SY removal (36.4%) for SY at 50 mg/L but provided stable floc formation, particularly in mixtures of anionic and cationic dyes. Application to real textile wastewater confirmed the high efficiency of the optimized coagulants, particularly with Al/pSi_20,A and AlCl₃, indicating their potential for industrial wastewater treatment. SEM, EDS, XRD, and FTIR analyses revealed structural consolidation, increased surface area, and successful dye adsorption, explaining the high removal efficiency. Full article

(This article belongs to the Special Issue Sediment Contamination and Metal Removal from Wastewater)

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32 pages, 6801 KB

Open AccessArticle

Discrete Heating and Outlet Ports’ Influences on Thermal Convection in Lid-Driven Vented Cavity System with Thermal Dispersion and LTNE Effects

by Luma F. Ali, Shibly A. AL-Samarraie and Amjad J. Humaidi

Processes 2025, 13(11), 3429; https://doi.org/10.3390/pr13113429 (registering DOI) - 25 Oct 2025

Abstract

An ambit of enhancing heat transfer throughout thermal convection in a cavity is explored numerically in this study, contemplating the heat dispersal from a segmental heat source circumscribed in a square-vented porous cavity with a moving lid. The cavity can be used as [...] Read more.

An ambit of enhancing heat transfer throughout thermal convection in a cavity is explored numerically in this study, contemplating the heat dispersal from a segmental heat source circumscribed in a square-vented porous cavity with a moving lid. The cavity can be used as a heat sink for electronic cooling, material processing, and convective drying. Aluminum

10

PPI metal foam saturated by aluminum oxide–water nanofluid is occupied in this lid-driven vented cavity system. The bottom cavity wall is fully and partially heated by a heat source of specific length

L_{H}

, and the left wall and inlet fluid are kept at the same cold temperature, while the right wall and top-driven wall are thermally insulated. Thermal dispersion and local thermal non-equilibrium effects are included in an energy equation, and continuity and Darcy–Brinkmann–Forchheimer momentum equations are implemented and resolved by utilizing the finite volume method with the aid of a vorticity–stream function approach operation. The inspirations behind pertinent parameters, including the Reynolds number (

R e = 10 - 50

), Grashof number (

G r = 10^{3} - 10^{6}

), inlet and outlet ports’ aspect ratio (

D / H = 0.1 - 0.4

), outlet port location ratio (

S / H = 0.25 - 0.75

), and discrete partial heating ratio (

L_{H} / L = 0.25 - 1

) are scrutinized. The baseline circumstance corresponds to full-length heating

L_{H} / L = 1

and the outlet port location ratio

S / H = 0.25

. The results reveal that the fluid and heat flow domains are addressed mostly via these specification alterations. For

G r = 10^{3}

, increasing

R e

from

10

to

40

does not alter streamlines or the isotherm field, but when

R e = 50

it is detected that streamlines increase monotonically. Streamlines are not altered when

L_{H} / L

and

S / H

are amplified but strengthened more when the opening vent aspect ratio is increased. A greater temperature difference occurs as

L_{H} / L

is raised from

0.25 - 0.75

and isotherms are intensified, and the thermal boundary layer becomes more distinct when

S / H

is augmented. The average Nusselt number rises as

R e

,

G r

,

L_{H} / L

, and

D / H

are increased by about

30 %

,

3.5 %

,

23 %

, and

19.4 %

, respectively, and it decreases with

S / H

amplifying is increased by around

5.5 %

. Full article

(This article belongs to the Special Issue Numerical Simulation and Application of Flow in Porous Media)

18 pages, 7910 KB

Open AccessFeature PaperArticle

Mixed-Dimensional 3D BiOCl Nanosheet Arrays/2D ZnO Nanoparticle Film Heterojunction Photodetectors with High Self-Powered Performance for Light Communication

by Mingmin Zhang and Weixin Ouyang

Processes 2025, 13(11), 3428; https://doi.org/10.3390/pr13113428 (registering DOI) - 25 Oct 2025

Abstract

High-performance self-powered ultraviolet (UV) photodetectors (PDs) based on mixed-dimensional 3D BiOCl nanosheet array/2D ZnO nanoparticle films heterojunction were fabricated via facile spin-coating and impregnation methods. Under zero bias, compared to the pristine ZnO PD exhibiting a large dark current (≈2 μA) and slow [...] Read more.

High-performance self-powered ultraviolet (UV) photodetectors (PDs) based on mixed-dimensional 3D BiOCl nanosheet array/2D ZnO nanoparticle films heterojunction were fabricated via facile spin-coating and impregnation methods. Under zero bias, compared to the pristine ZnO PD exhibiting a large dark current (≈2 μA) and slow response time (>20 s/>20 s), the optimized 2-BiOCl-ZnO heterojunction PD demonstrated a dramatically suppressed dark current (≈1 nA), along with an ultrahigh on/off ratio (22,748) and a shorter response time (17.44 ms/14 ms) under 365 nm light illumination. This optimized device also achieved a remarkable responsivity of 1.08 A·W⁻¹ and a detectivity of 2.48 × 10¹³ Jones at 354 nm. The built-in electric field formed at the BiOCl-ZnO heterojunction interface, the improved light absorption enabled by the mixed-dimensional heterostructure, and the optimized charge carrier separation and transport within the device were responsible for the enhanced self-powered performance. Due to its fascinating photoelectric properties, this PD was applied as a self-powered signal receiver in a UV optical communication system, demonstrating the ability to achieve efficient and high-speed message transmission. The rational construction of BiOCl-based heterojunction has proved to be an efficient pathway to achieving self-powered photodetection. These results demonstrate that the rational construction of heterojunctions holds great potential for fabricating high-performance PDs. Full article

(This article belongs to the Special Issue Preparation of Semiconductor Materials and Their Application in Photoelectronic Devices)

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20 pages, 1156 KB

Open AccessArticle

A New Control Tracking Approach for the Congestion Problem of a TCP System Based on Nonlinear Sliding Mode Control

by Chaimae El Mortajine and Mostafa Bouzi

Processes 2025, 13(11), 3427; https://doi.org/10.3390/pr13113427 (registering DOI) - 25 Oct 2025

Abstract

In this paper, we propose two control approaches based on sliding mode control (SMC) to address the congestion problem in transmission control protocol (TCP) systems. First, a nonlinear sliding variable is introduced using a

K_{1}

function, which ensures robustness and finite-time convergence. [...] Read more.

In this paper, we propose two control approaches based on sliding mode control (SMC) to address the congestion problem in transmission control protocol (TCP) systems. First, a nonlinear sliding variable is introduced using a

K_{1}

function, which ensures robustness and finite-time convergence. Based on this sliding variable, a suitable switching controller is designed. Additionally, a continuous version of the controller is developed using the arctangent function to reduce chattering. Two simulation scenarios are presented to validate the effectiveness of the proposed control schemes in terms of congestion control and tracking performance. Full article

(This article belongs to the Special Issue Innovative Approaches to Modeling, Optimization, Control, and Monitoring in Industrial Processes)

15 pages, 2809 KB

Open AccessArticle

La³⁺/Bi³⁺ Co-Doping in BaTiO₃ Ceramics: Structural Evolution and Enhanced Dielectric Properties

by María Inés Valenzuela-Carrillo, Miguel Pérez-Labra, Francisco Raúl. Barrientos-Hernandez, Antonio Romero-Serrano, Irma Mendoza-Sanchez, Alejandro Cruz-Ramírez, Mizraim U. Flores, Martín Reyes-Pérez and Julio C. Juárez-Tapia

Processes 2025, 13(11), 3426; https://doi.org/10.3390/pr13113426 (registering DOI) - 25 Oct 2025

Abstract

La³⁺/Bi³⁺ co-doped BaTiO₃ ceramics were synthesized via ball milling followed by heat treatment at 1200 °C according to the Ba_1−3xLa_2xTi_1−3xBi_4xO₃ formula, with dopant levels ranging from x = 0.0 to [...] Read more.

La³⁺/Bi³⁺ co-doped BaTiO₃ ceramics were synthesized via ball milling followed by heat treatment at 1200 °C according to the Ba_1−3xLa_2xTi_1−3xBi_4xO₃ formula, with dopant levels ranging from x = 0.0 to 0.006. X-ray diffraction and Rietveld refinement confirmed a ferroelectric tetragonal phase for all compositions, with the highest tetragonality (c/a = 1.009) observed for x = 0.001 exceeding that of pure BaTiO₃ (1.0083). High-resolution electron microscopy analysis revealed faceted particles with mean sizes between 362.5 nm and 488.3 nm. Low-doped samples (x = 0.001 and 0.002) exhibited higher permittivity than undoped BaTiO₃, with the maximum dielectric constant (ε_r = 2469.0 at room temperature and 7499.7 at the Curie temperature) recorded for x = 0.001 at 1 kHz. At x = 0.006, minimal permittivity variation indicated a stable dielectric response. A decrease in the Curie temperature was observed with increasing doping levels, indicating a progressive tendency toward the cubic phase. Critical exponent γ values (0.94–1.56) indicated a sharp phase transition for low-doped samples and a diffuse transition for highly doped BaTiO₃. These results showed that La³⁺/Bi³⁺ co-doping effectively tunes the structural and dielectric properties of BaTiO₃ ceramics. Full article

(This article belongs to the Special Issue Microstructure Properties and Characterization of Metallic Material)

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21 pages, 9357 KB

Open AccessArticle

Genesis of Meniscus Dynamic Distortions (MDDs) in a Medium Slab Mold Driven by Unstable Upward Flows

by Eriwiht Dominic Tello-Cabrera, Saúl García-Hernández, Enif Gutierrez, Rodolfo Morales Dávila, Jose de Jesus Barreto and Rumualdo Servín-Castañeda

Processes 2025, 13(11), 3425; https://doi.org/10.3390/pr13113425 (registering DOI) - 25 Oct 2025

Abstract

To better understand the relationship between meniscus instabilities and the high levels of turbulence in the fluid dynamics of a continuous medium slab mold, this study investigates the magnitudes of meniscus dynamics distortions and their fluid dynamic origin using a full-scale water modeling [...] Read more.

To better understand the relationship between meniscus instabilities and the high levels of turbulence in the fluid dynamics of a continuous medium slab mold, this study investigates the magnitudes of meniscus dynamics distortions and their fluid dynamic origin using a full-scale water modeling experiment and mathematical simulations. The three-dimensional mathematical model is composed of the continuity and momentum equations, together with the standard k-ε turbulence model and the volume of fluid model, to track the dynamics of the steel interface. The results show that the medium slab mold shares flow patterns common to both conventional slab molds and funnel thin slab molds, making its fluid dynamics more complex. Despite this, the fluid dynamics within the mold do not develop a dynamic distortion phenomenon but induce upward stream flows with instability and high velocities, which generate an unstable meniscus behavior characterized by significant surface oscillations, variations in velocity, and high deformations. These latter flow characteristics are the origin of meniscus dynamic distortion (MDD), which shows a constant frequency with non-constant periodicity and different median lifecycle ranges. Full article

(This article belongs to the Special Issue Numerical Simulation and Heat Transfer in Material Processing and Casting Engineering)

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19 pages, 1583 KB

Open AccessArticle

Immobilization of Bioimprinted Phospholipase D and Its Catalytic Behavior for Transphosphatidylation in the Biphasic System

by Bishan Guo, Huiyi Shang, Juntan Wang, Hongwei Liu and Haihua Zhu

Processes 2025, 13(11), 3424; https://doi.org/10.3390/pr13113424 (registering DOI) - 24 Oct 2025

Abstract

Phosphatidylserine (PS) holds considerable importance in both the food and medical sectors; however, its biosynthesis is critically dependent on phospholipase D (PLD). The practical application of PLD is constrained by pronounced side reactions in its free form and by reduced selectivity when immobilized. [...] Read more.

Phosphatidylserine (PS) holds considerable importance in both the food and medical sectors; however, its biosynthesis is critically dependent on phospholipase D (PLD). The practical application of PLD is constrained by pronounced side reactions in its free form and by reduced selectivity when immobilized. To address these challenges, this study employed a sequential strategy involving bioimprinting to hyperactivate PLD, followed by microencapsulation via ionotropic gelation within an alginate–chitosan matrix. This approach induced conformational rigidification, enabling PLD to maintain its hyperactivated state in aqueous environments. Under optimal conditions, the encapsulation efficiency reached 78.56%, and the enzyme activity recovery achieved 105.27%. The immobilized bioimprinted PLD demonstrated exceptional catalytic performance, achieving a 94.68% PS yield within 20 min, which significantly surpassed that of free PLD (85.82% in 150 min) and non-imprinted immobilized PLD (90.34% in 60 min). This represents 7.27-fold and 2.14-fold efficiency improvements, respectively. Furthermore, the biocatalyst exhibited outstanding storage stability, thermal stability, and reusability (77.53% yield after 8 cycles). To our knowledge, this is the first report combining bioimprinting with alginate-chitosan microencapsulation via ionotropic gelation, which yielded remarkably enhanced PLD activity. These findings highlight the strong potential of this method for efficient PS production. Full article

(This article belongs to the Section Materials Processes)

13 pages, 2914 KB

Open AccessArticle

Efficient Bioreduction of Cr(VI) by a Halotolerant Acinetobacter sp. ZQ-1 in High-Salt Environments: Performance and Metabolomic Mechanism

by Lei Yu, Qi Zhou and Jing Liang

Processes 2025, 13(11), 3423; https://doi.org/10.3390/pr13113423 (registering DOI) - 24 Oct 2025

Abstract

Bioreduction is an effective method to reduce Cr(VI) for bioremediation. In this study, a hexavalent chromium-reducing bacterium with salt tolerant abilities, Acinetobacter ZQ-1, was isolated, which could efficiently reduce Cr(VI) under a wide range of pH (6.0–9.0), temperatures (28–42 °C) and coexisting heavy [...] Read more.

Bioreduction is an effective method to reduce Cr(VI) for bioremediation. In this study, a hexavalent chromium-reducing bacterium with salt tolerant abilities, Acinetobacter ZQ-1, was isolated, which could efficiently reduce Cr(VI) under a wide range of pH (6.0–9.0), temperatures (28–42 °C) and coexisting heavy metals (Mn²⁺, Pb²⁺ and Fe³⁺). It is worth mentioning that the strain ZQ-1 could reduce Cr(VI) containing 15% (w/v) NaCl, showing strong salt tolerance. Under optimal culture conditions, strain ZQ-1 was able to completely reduce 50 mg/L of Cr(VI) in 24 h. The metabolic data of ZQ-1 showed that salt stress significantly altered the composition of metabolites, in which the accumulation of compatible solutes such as Arginine, Leucine, Lysine and Proline contributed to the alleviation of high salt stress for strain ZQ-1. Meanwhile, the increased content of alginate and betaine also helped to maintain the normal function of strain ZQ-1 in a high-salt environment. This is of great significance for the development, utilization and mechanism of action of salt-tolerant hexavalent chromium-reducing bacteria in the future. Full article

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

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24 pages, 3293 KB

Open AccessArticle

Short-Term Forecasting of Photovoltaic Clusters Based on Spatiotemporal Graph Neural Networks

by Zhong Wang, Mao Yang, Yitao Li, Bo Wang, Zhao Wang and Zheng Wang

Processes 2025, 13(11), 3422; https://doi.org/10.3390/pr13113422 (registering DOI) - 24 Oct 2025

Abstract

Driven by the dual-carbon goals, photovoltaic (PV) battery systems at renewable energy stations are increasingly clustered on the distribution side. The rapid expansion of these clusters, together with the pronounced uncertainty and spatio-temporal heterogeneity of PV generation, degrades battery utilization and forces conservative [...] Read more.

Driven by the dual-carbon goals, photovoltaic (PV) battery systems at renewable energy stations are increasingly clustered on the distribution side. The rapid expansion of these clusters, together with the pronounced uncertainty and spatio-temporal heterogeneity of PV generation, degrades battery utilization and forces conservative dispatch. To address this, we propose a “spatio-temporal clustering–deep estimation” framework for short-term interval forecasting of PV clusters. First, a graph is built from meteorological–geographical similarity and partitioned into sub-clusters by a self-supervised DAEGC. Second, an attention-based spatio-temporal graph convolutional network (ASTGCN) is trained independently for each sub-cluster to capture local dynamics; the individual forecasts are then aggregated to yield the cluster-wide point prediction. Finally, kernel density estimation (KDE) non-parametrically models the residuals, producing probabilistic power intervals for the entire cluster. At the 90% confidence level, the proposed framework improves PICP by 4.01% and reduces PINAW by 7.20% compared with the ASTGCN-KDE baseline without spatio-temporal clustering, demonstrating enhanced interval forecasting performance. Full article

(This article belongs to the Special Issue Power System Optimization for Energy Storage: Methods and Applications)

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18 pages, 9366 KB

Open AccessArticle

Multi-Objective Rolling Linear-Programming-Model-Based Predictive Control for V2G-Enabled Electric Vehicle Scheduling in Industrial Park Microgrids

by Tianlu Luo, Feipeng Huang, Houke Zhou and Guobo Xie

Processes 2025, 13(11), 3421; https://doi.org/10.3390/pr13113421 (registering DOI) - 24 Oct 2025

Abstract

With the rapid growth of electricity demand in industrial parks and the increasing penetration of renewable energy, vehicle-to-grid (V2G) technology has become an important enabler for mitigating grid stress while improving charging economy. This paper proposes a multi-objective rolling linear-programming-model-based predictive control (LP-MPC) [...] Read more.

With the rapid growth of electricity demand in industrial parks and the increasing penetration of renewable energy, vehicle-to-grid (V2G) technology has become an important enabler for mitigating grid stress while improving charging economy. This paper proposes a multi-objective rolling linear-programming-model-based predictive control (LP-MPC) method for coordinated electric vehicle (EV) scheduling in industrial park microgrids. The model explicitly considers transformer capacity limits, EV state-of-charge (SOC) dynamics, bidirectional charging/discharging constraints, and photovoltaic (PV) generation uncertainty. By solving a linear programming problem in a receding horizon framework, the approach simultaneously achieves load peak shaving, valley filling, and EV revenue maximization with real-time feasibility. A simulation study involving 300 EVs, 100 kW PV, and a 1000 kW transformer over 24 h with 5-min intervals demonstrates that the proposed LP-MPC outperforms greedy and heuristic load-leveling strategies in peak load reduction, load variance minimization, and charging cost savings while meeting all SOC terminal requirements. These results validate the effectiveness, robustness, and economic benefits of the proposed method for V2G-enabled industrial park microgrids. Full article

(This article belongs to the Special Issue AI-Driven Optimization in Intelligent Process Control for Power and Energy Systems)

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22 pages, 3822 KB

Open AccessArticle

Eco-Friendly and Sustainable One-Component Polyurethane Syntactic Foams Reinforced with Fly Ash Cenospheres for Acoustic and Thermal Insulation

by Hakkı Özer and Anıl Burak Bektaşoğlu

Processes 2025, 13(11), 3420; https://doi.org/10.3390/pr13113420 (registering DOI) - 24 Oct 2025

Abstract

In this study, syntactic composite foams were developed by incorporating cenosphere (CS) particles recovered from recycled fly ash into a one-component polyurethane (PU) foam system. During production, CS was added to the spray-applied PU foam at specific ratios, and the foaming reaction was [...] Read more.

In this study, syntactic composite foams were developed by incorporating cenosphere (CS) particles recovered from recycled fly ash into a one-component polyurethane (PU) foam system. During production, CS was added to the spray-applied PU foam at specific ratios, and the foaming reaction was simultaneously initiated via manual mixing. This approach minimized particle settling caused by the filler–matrix density difference and promoted a more homogeneous structure. Two types of CS, with mean sizes of approximately 70 µm and 130 µm, were incorporated at five loadings ranging from 5 wt% to 15 wt%. The resulting composites were evaluated for their acoustic, mechanical, and thermal performance. Thermal analyses revealed that CS addition increased the glass-transition temperature (Tg) by ≈12 °C and delayed the 5% mass-loss temperature (T₅%) by ≈30–35 °C compared with the neat N2 foam, confirming the stabilizing role of cenospheres. The refoaming process with manual mixing promoted finer cell diameters and thicker walls, enhancing the sound absorption coefficient (α), particularly at medium and high frequencies. Moreover, increasing the filler content improved both the sound transmission loss (STL) and compressive strength, alongside density, although further gains in α and STL were limited beyond a 10 wt% filler content. Significant enhancements in compressive strength were achieved at filler ratios above 12.5 wt%. Unlike conventional two-component PU foams, this study demonstrates a sustainable one-component PU system reinforced with recycled cenospheres that simultaneously achieves acoustic, mechanical, and thermal multifunctionality. To the best of our knowledge, this is the first report on incorporating recycled cenospheres into a one-component PU foam system, overcoming dispersion challenges of conventional two-component formulations and presenting an environmentally responsible route for developing versatile insulation materials. Full article

(This article belongs to the Special Issue Thermal Properties of Composite Materials)

13 pages, 999 KB

Open AccessArticle

Statistical Analysis of Heat Transfer Effects on Flow Patterns Maps in a Flat-Plate Collector/Evaporator with R600a Under Variable Tilt Angles

by William Quitiaquez, Isaac Simbaña, Alex Herrera, Patricio Quitiaquez, César Nieto-Londoño, Erika Pilataxi, Anthony Xavier Andrade and Yoalbys Retirado-Mediaceja

Processes 2025, 13(11), 3419; https://doi.org/10.3390/pr13113419 (registering DOI) - 24 Oct 2025

Abstract

This present investigative work proceeds with the statistical study of the heat transfer coefficient (CTC) in the different flow transitions that are formed in a horizontal pipe with variation in the angles of inclination in a collector/evaporator component of a heat pump of [...] Read more.

This present investigative work proceeds with the statistical study of the heat transfer coefficient (CTC) in the different flow transitions that are formed in a horizontal pipe with variation in the angles of inclination in a collector/evaporator component of a heat pump of solar assisted direct expansion (DX-SAHP) by using R600a refrigerant as working fluid in Quito - Ecuador. The dimensions of the collector/evaporator are 3.8 and 1000 mm inside diameter and length, respectively. To determine the results obtained, five practical tests are carried out with inclination angles of 10, 20, 30, 40 and 45°, with speeds or mass flows that vary between 203.24 and 222.28 kg·m⁻²·s⁻¹, the heat fluxes reached values between 200.58 and 507.23 W·m⁻². The correlations proposed by Kattan, Kundu, and Mohseni, and the experimental data were considered for the analysis of the effects of heat transfer on flow patterns. The results obtained from the investigation show that the maximum CTC is 6163.83 W·m⁻²·K⁻¹ with an inclination angle of 45°. Statistical analysis was performed considering the direction of Pearson presented results that for the angle of inclination of 10° a greater inverse direction of −0.316 is obtained. Full article

(This article belongs to the Special Issue Numerical Simulation of Flow and Heat Transfer Processes)

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