Processes

15 pages, 518 KiB

Open AccessReview

Application of Ultrasound in Proteins: Physicochemical, Structural Changes, and Functional Properties with Emphasis on Foaming Properties

by José Ramón Antunez-Medina, Guadalupe Miroslava Suárez-Jiménez, Víctor Manuel Ocano-Higuera, Iván de Jesús Tolano-Villaverde, José de Jesús Ornelas-Paz, Wilfrido Torres-Arreola and Enrique Márquez-Ríos

Processes 2025, 13(6), 1646; https://doi.org/10.3390/pr13061646 - 23 May 2025

Abstract

Proteins have the ability to form foam, which is a system consisting of a gas phase dispersed within a continuous phase, either liquid or solid. In certain types of food, the incorporation of gas is important for maintaining quality and sensory attributes. However, [...] Read more.

Proteins have the ability to form foam, which is a system consisting of a gas phase dispersed within a continuous phase, either liquid or solid. In certain types of food, the incorporation of gas is important for maintaining quality and sensory attributes. However, foam is a thermodynamically unstable system, and its stabilization is a highly researched area. In recent years, there has been growing interest in the application of ultrasound not only to improve foaming properties, but also to alter physicochemical and structural characteristics of proteins, making it an environmentally friendly and versatile technology. Ultrasound can enhance formation and stability by inducing conformational changes through the cavitation phenomenon. However, the benefits of this technology depend on the inherent characteristics of the proteins and the conditions applied during its use, such as frequency, time, amplitude, energy, protein concentration, volume, and medium conditions. This review aims to explore how ultrasound influences the physicochemical properties, induces structural modifications, and consequently enhances functional characteristics such as foaming capacity. Full article

(This article belongs to the Special Issue Application and Development of Ultrasonic Technology in Food Processing)

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14 pages, 3909 KiB

Open AccessArticle

Application of Blasingame’s Modern Production-Decline Analysis Method in Production Performance Analysis of Buried Hill Condensate Gas Reservoir

by Lingang Lv, Peng Chen and Hang Lai

Processes 2025, 13(6), 1645; https://doi.org/10.3390/pr13061645 - 23 May 2025

Abstract

With the increase in exploration in recent years, buried hill condensate gas reservoirs have gradually become an important field for increasing reserves and production of offshore oil and gas in China, and efficient development of condensate gas reservoirs has also become a hot [...] Read more.

With the increase in exploration in recent years, buried hill condensate gas reservoirs have gradually become an important field for increasing reserves and production of offshore oil and gas in China, and efficient development of condensate gas reservoirs has also become a hot issue in hydrocarbon development. Due to the complex phase-change law and retrograde condensation phenomenon of deep condensate gas reservoirs, the reservoir properties and production dynamics data obtained by conventional pressure-recovery-test methods were greatly limited, and the dynamic data and evaluation parameters of the single well control area cannot be accurately determined. In this paper, using the production analysis method to analyze the production dynamics data of a single well, combined with static geological data and well-test analysis data, the reservoir parameters of a single well were evaluated. Specifically, the Blasingame method was applied to realize the production-decline law of production wells, and new dimensionless flow, pressure parameters, and pseudo-time functions were introduced. Using the unstable well test theory and the traditional production decline analysis technology, the IHS Harmony software is used to fit the production dynamic data with the theoretical chart. The evaluation parameters such as reservoir permeability, skin factor, well control radius, and well control reserves were calculated, providing strong support for the production decision-making of the petroleum industry and also providing a strong decision-making basis for the dynamic adjustment of oil–gas-well manufacture. Full article

(This article belongs to the Section Energy Systems)

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35 pages, 805 KiB

Open AccessFeature PaperArticle

Isolation, Identification, and Characterization of Probiotic Properties of Lactic Acid Bacterial Strains Isolated from Rose Blossom of Rosa damascena Mill

by Zapryana Denkova, Polina Zapryanova, Yordanka Gaytanska, Bogdan Goranov, Vesela Shopska, Rositsa Denkova-Kostova and Georgi Kostov

Processes 2025, 13(6), 1644; https://doi.org/10.3390/pr13061644 - 23 May 2025

Abstract

This study on the isolation, identification, and characterization of the probiotic properties of lactic acid bacterial strains from the rose blossom of Rosa damascena Mill. (R. damascena) is crucial for discovering novel, plant-derived probiotics with potential health benefits and applications in [...] Read more.

This study on the isolation, identification, and characterization of the probiotic properties of lactic acid bacterial strains from the rose blossom of Rosa damascena Mill. (R. damascena) is crucial for discovering novel, plant-derived probiotics with potential health benefits and applications in food, medicine, and cosmetics. Nine lactic acid bacterial (LAB) strains were isolated from rose blossom of R. damascena, and they were identified to the species level by applying physiological and biochemical (API 50 CHL), and molecular genetic (16S rRNA gene sequencing) methods. The isolates were identified as belonging to the Lactobacillus helveticus, Lactobacillus acidophilus, and Lactiplantibacillus plantarum species. Some probiotic properties of the newly isolated and identified LAB strains were examined: their antibacterial activity against pathogens by the agar well diffusion method, and their antibiotic resistance profile by the agar paper disc diffusion method. The LAB strains studied demonstrated significant antibacterial activity against the Escherichia coli, Staphylococcus aureus, Salmonella Abony, Proteus vulgaris, Listeria monocytogenes, and Enterococcus faecalis pathogens and were resistant to most of the antibiotics used in clinical practice, which in turn suggested the possibility of their joint inclusion in therapy, in the composition of probiotic preparations. A batch fermentation process was conducted with Lactiplantibacillus plantarum 5/20, and the kinetic parameters of the batch fermentation process were determined in order to obtain a concentrate with a high viable cell count (10¹³CFU/cm³). The resultant concentrate was freeze-dried, and freeze-dried preparations with a high viable cell count (over 10¹² CFU/g) were obtained. Research on LAB strains isolated from R. damascena could reveal valuable LAB strains with significant probiotic properties. These strains will be suitable for various applications in the composition of starter cultures for functional beverages and foods, as well as probiotic preparations, showcasing the untapped potential of plant-associated microbiota. Full article

(This article belongs to the Special Issue Feature Papers in the "Food Process Engineering" Section)

24 pages, 5469 KiB

Open AccessArticle

The Impact of the Feed Rate and the Binder Concentration on the Morphology of Spray-Dried Alumina–Polymer Nanocomposites

by Rahul Mitra, Lukas Fuchs, Orkun Furat, Yannik Sinnwell, Sergiy Antonyuk, Volker Schmidt and Urs Alexander Peuker

Processes 2025, 13(6), 1643; https://doi.org/10.3390/pr13061643 - 23 May 2025

Abstract

Spray-drying is a flexible method for creating fine porous composites with controlled size and morphology. This study investigates how the morphology and porosity of the spray-dried powder of nano-alumina and polyvinylpyrrolidone (PVP-30) granules are affected by both the feed rate and the binder [...] Read more.

Spray-drying is a flexible method for creating fine porous composites with controlled size and morphology. This study investigates how the morphology and porosity of the spray-dried powder of nano-alumina and polyvinylpyrrolidone (PVP-30) granules are affected by both the feed rate and the binder concentration. Droplet size and velocity distributions, measured with a HiWatch system, showed that higher feed rates produce larger droplets with faster velocities, therefore affecting the final morphology of the dried product. The morphology of the dried granules was analyzed using inline SOPAT imaging. While mercury intrusion porosimetry quantified the nano-pore volume and nano-pore size of the granules, offline scanning electron microscopy (SEM) was also used to characterize the morphology of the dried product. The findings show that, while raising the binder concentration produces a more compact morphology with a lower nano-pore volume, higher feed rates produce larger granules with a larger nano-pore volume. This study offers fundamental insights that can support the future development of control strategies for optimizing the production of spray-dried porous alumina–polymer nanocomposites by means of knowledge about the relationship between these process parameters and product qualities. Full article

(This article belongs to the Section Materials Processes)

16 pages, 7350 KiB

Open AccessArticle

Study on the Mechanisms of Floor Heave in Roadways and Control Strategies via Grooving and Pressure Relief

by Tongxi Li, Bingyuan Hao and Chaoyao Shi

Processes 2025, 13(6), 1642; https://doi.org/10.3390/pr13061642 - 23 May 2025

Abstract

With the increasing depth of mining operations, roadways experience higher ground stress and pronounced deformation. Elevated in situ stress leads to a continuous rise in vertical stress on surrounding rock. The excavation of roadways and working faces further redistributes the stress field, resulting [...] Read more.

With the increasing depth of mining operations, roadways experience higher ground stress and pronounced deformation. Elevated in situ stress leads to a continuous rise in vertical stress on surrounding rock. The excavation of roadways and working faces further redistributes the stress field, resulting in more frequent and severe floor heave. To address this issue in the 1232 transportation roadway of Shuguang Coal Mine, a numerical model was developed using the discrete element method (PFC2D) to systematically analyze the impacts of floor stiffness, strength, and joint distribution on heave mechanisms. A mechanical device for underground slotting operations was designed, and the optimal slotting depth was determined through simulation. The results indicate that floor heave stems from progressive failure of composite strata, governed by stiffness, strength, and moment of inertia (influenced by strata thickness and joint development). Effective suppression requires slotting depths to penetrate the shallow fractured zone and reach the load-bearing structure. Stress arching effects significantly mitigate deformation at 2.5 m depth, providing a theoretical basis for optimal slotting design. Full article

(This article belongs to the Special Issue Advances in Coal Processing, Utilization, and Process Safety)

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15 pages, 9789 KiB

Open AccessArticle

Study on Rational Roadway Layout and Air Leakage Prevention in Shallow Close-Distance Coal Seam Mining

by Ying Liu

Processes 2025, 13(6), 1641; https://doi.org/10.3390/pr13061641 - 23 May 2025

Abstract

To address the issues of roadway instability and severe air leakage in goaf areas during overlapping coal pillar mining in shallow multi-seam coalfields, this study takes the 22,209 working face of Huojitu Shaft in the Shendong Daliuta Mine as the research object. Using [...] Read more.

To address the issues of roadway instability and severe air leakage in goaf areas during overlapping coal pillar mining in shallow multi-seam coalfields, this study takes the 22,209 working face of Huojitu Shaft in the Shendong Daliuta Mine as the research object. Using the discrete element method (DEM), the optimal layout of roadways in the lower coal seam and the corresponding evolution of overburden fractures were simulated. In addition, the effectiveness of goaf backfilling in controlling overburden air leakage channels was analyzed and verified. The results indicate that the width of coal pillars in the upper seam should be greater than approximately 23 m to ensure that roadways remain in a stress-stable zone. Roadways in the lower seam should be horizontally arranged within a range of 35–55 m from the center of the overlying coal pillar. This layout effectively avoids placing the roadway beneath the high-stress concentration zone or the pressure-relief area of the goaf. After mining the upper coal seam, the overburden collapse zone takes on a “trapezoidal” shape, and mining-induced fractures develop upward to the surface, forming vertical and inclined fracture channels that penetrate to the surface, resulting in severe air leakage in the goaf. Following the mining of the lower seam, the interlayer strata are completely fractured, leading to secondary development of fractures in the overlying old goaf. This results in the formation of a connected fracture network spanning from the surface through the seam goaf linkage. Implementing goaf backfilling measures significantly reduces the vertical settlement of the overburden, prevents the formation of through-layer air leakage channels, and effectively mitigates interlayer air leakage problems during lower-seam mining. Full article

(This article belongs to the Special Issue Advances in Coal Processing, Utilization, and Process Safety)

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14 pages, 8156 KiB

Open AccessArticle

Light-Triggered Core Coalescence of Double-Emulsion Droplets for High-Throughput Microreaction on a LiNbO₃ Platform

by Mengtong Wang, Wenbo Yan and Lihong Shi

Processes 2025, 13(6), 1640; https://doi.org/10.3390/pr13061640 - 23 May 2025

Abstract

Optically triggering the core coalescence of double-emulsion droplets remains challenging. Herein, we utilize a photovoltaic field generated by laser illumination on LiNbO₃ crystals to trigger the core coalescence in a high-throughput manner. The synergy between the interfacial pressure of the shell droplet [...] Read more.

Optically triggering the core coalescence of double-emulsion droplets remains challenging. Herein, we utilize a photovoltaic field generated by laser illumination on LiNbO₃ crystals to trigger the core coalescence in a high-throughput manner. The synergy between the interfacial pressure of the shell droplet and the internal flow induced by the photovoltaic field facilitates the core coalescence. With an increase in the core number, the illumination intensity required for the core coalescence is found to increase initially, whereas it tends to saturate at 5 × 10⁷ W/m², an intensity that does not cause a large temperature increase (<4 °C). The effective mixing of the substances contained in two core droplets after their coalescence is also verified. The proposed technique provides a precise, non-thermal and electrodeless strategy for high-throughput biochemical microreactions. Full article

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

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19 pages, 9538 KiB

Open AccessArticle

Research on the Impact Resistance of Sandwich-Structured Battery Pack Protective Plates

by Jun Zhou, Changjie Luo, Ruilin Shen, Fengqiang Zhang, Wenze Yu, Mingming Zhang and Weiliang Liao

Processes 2025, 13(6), 1639; https://doi.org/10.3390/pr13061639 - 23 May 2025

Abstract

With the continuous development of the new energy vehicle industry, in order to further improve the safety and range of electric vehicles, vehicle lightweighting has been a key focus of major car companies. However, research on lightweighting and the impact protection effect of [...] Read more.

With the continuous development of the new energy vehicle industry, in order to further improve the safety and range of electric vehicles, vehicle lightweighting has been a key focus of major car companies. However, research on lightweighting and the impact protection effect of battery pack protective plates is lacking. The bottom protective plate of the battery pack in this study has a sandwich-type multi-layer structure, which is mainly composed of upper and lower glass-fiber-reinforced resin protective layers, steel plate impact resistant layers, and honeycomb buffer layers. In order to study the relationship between the impact damage response and material characteristics of the multi-material battery pack protective plate, a matrix experimental design was adopted in this study to obtain the energy absorption ratio of different material properties when the protective plate is subjected to impact damage. This work innovatively used a low-cost equivalent model method. During the drop hammer impact test, a 6061-T6 aluminum plate in direct contact with the lower part of the bottom guard plate test piece was used to simulate the deformation of the water-cooled plate in practical applications. High-strength aluminum honeycomb was arranged below the aluminum plate to simulate the deformation of the battery cell. This method provides a scientific quantitative standard for evaluating the impact resistance performance of the protective plate. The most preferred specimen in this work had a surface depression deformation of only 8.44 mm after being subjected to a 400 J high-energy impact, while the simulated water-cooled plate had a depression deformation of 4.07 mm. Among them, the high-strength steel plate played the main role in absorbing energy during the impact process, absorbing energy. It can account for about 34.3%, providing reference for further characterizing the impact resistance performance of the protective plate under different working conditions. At the same time, an equivalence analysis of the damage mode between the quasi-static indentation test and the dynamic drop hammer impact test was also conducted. Under the same conditions, the protective effect of the protective plate on impact damage was better than that of static pressure marks. From the perspective of energy absorption, the ratio coefficient of the two was about 1.2~1.3. Full article

(This article belongs to the Special Issue Micro/Nano Manufacturing Processes: Theories and Optimization Techniques (2nd Edition))

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18 pages, 1517 KiB

Open AccessArticle

Power Supply Resilience Under Typhoon Disasters: A Recovery Strategy Considering the Coordinated Dispatchable Potential of Electric Vehicles and Mobile Energy Storage

by Xinyi Dong, Xiaofu Xiong, Di Yang, Song Wang and Yanghaoran Zhu

Processes 2025, 13(6), 1638; https://doi.org/10.3390/pr13061638 - 23 May 2025

Abstract

In recent years, extreme natural disasters, such as typhoons, have become increasingly frequent, leading to persistent power outages in urban distribution grids. These outages pose significant challenges to the stability of urban power supply systems. With the growing number of electric vehicle (EV) [...] Read more.

In recent years, extreme natural disasters, such as typhoons, have become increasingly frequent, leading to persistent power outages in urban distribution grids. These outages pose significant challenges to the stability of urban power supply systems. With the growing number of electric vehicle (EV) users and the expanding EV industry, and considering the potential of EVs as flexible load storage resources, this paper proposes a post-disaster power supply restoration strategy that takes into account the potential of coordinated scheduling of EVs and mobile energy storage. First, a compression method based on the Minkowski addition is proposed for the EV cluster model in charging stations, which establishes an EV dispatchable model. Second, the spatiotemporal matrix of failure rates for distribution network elements is calculated using the Batts wind field model, enabling the generation of distribution network failure scenarios under typhoon conditions. Finally, the power supply restoration strategy of multi-source coordination with the participation of EV cluster and mobile storage is formulated with the objective of minimizing the loss of the distribution network side. Simulation results demonstrate that the proposed strategy effectively utilizes the load storage potential of EVs and mobile energy storage, enhances recovery performance, ensures cost-effectiveness, and explicitly solves the islanding operation stability problem. Full article

(This article belongs to the Special Issue Recent Advances in Sustainable Electrical Energy Technologies (2nd Edition))

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30 pages, 4701 KiB

Open AccessArticle

Electrocoagulation with Fe-SS Electrodes as a Fourth Stage of Tequila Vinasses Treatment for COD and Color Removal

by Rafael González Pérez, Aída Lucía Fajardo Montiel, Edgardo Martínez Orozco, Norberto Santiago Olivares, Juan Nápoles Armenta and Celestino García Gómez

Processes 2025, 13(6), 1637; https://doi.org/10.3390/pr13061637 - 23 May 2025

Abstract

The tequila industry faces several environmental challenges due to its high yields of contaminants, especially tequila distillation stillage or tequila vinasses, with ten to twelve liters produced per liter of tequila. All treatments aim to shorten retention times to avoid the need for [...] Read more.

The tequila industry faces several environmental challenges due to its high yields of contaminants, especially tequila distillation stillage or tequila vinasses, with ten to twelve liters produced per liter of tequila. All treatments aim to shorten retention times to avoid the need for large equipment or new facilities and the saturation of residues within tequila distilleries. The complexity of tequila vinasses has led to treatments with several stages, whereby most of the organic matter content is reduced, but the treatment range results are insufficient. This study aimed to evaluate a fourth-stage tequila vinasse treatment using an electrocoagulation system that uses inexpensive electrodes (SS cathodes and iron anodes), has a low electrical consumption, and applies low voltages in order to meet safety, economic, and environmental criteria so as to comply with Mexican norm NOM-001-SEMARNAT-2021. Three sets of voltage–amperage controllable power source, a 4 mm cylindrical 304 stainless-steel cathode, and a 9 mm iron anode with 200 mL samples in 250 mL beakers were used; three replicas (R1, R2, and R3) underwent 2 h treatment at 1–6 volts to evaluate the voltage effect and 1–6 h of 5-volt treatment to assess the time effect. All samples were filtered with 8 μm and 0.25 μm meshes. Chemical oxygen demand, pH, electrical conductivity, turbidity, and color measurements (SAC for λ 436, 525, and 620 nm) were taken. The experiments determined the optimal voltage and time, considering a hydraulic retention time below 6 h. The results show that electrocoagulation of pretreated tequila vinasses effectively helps in the final removal of organic matter measured as COD, reaching values below 150 COD mg/L at 5–6 h with 5 V treatments and color reduction with 5 V, 1 h treatment. This leads to final polishing that complies with the Mexican wastewater discharge norm criteria. Full article

(This article belongs to the Section Environmental and Green Processes)

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11 pages, 700 KiB

Open AccessArticle

A Simple Method to Determine Pheomelanin Content and Structure in FFPE Human Melanoma Specimens

by Slawomir Kurkiewicz, Łukasz Marek, Irena Tam, Agata Stanek-Widera, Dariusz Lange and Jerzy Stojko

Processes 2025, 13(6), 1636; https://doi.org/10.3390/pr13061636 - 23 May 2025

Abstract

Human cutaneous malignant melanoma is a skin cancer that develops from melanocytes, the cells specialised in the production of eu- and pheomelanin. A growing body of evidence suggests that pheomelanin in particular is involved in melanoma development. The aim of this study was [...] Read more.

Human cutaneous malignant melanoma is a skin cancer that develops from melanocytes, the cells specialised in the production of eu- and pheomelanin. A growing body of evidence suggests that pheomelanin in particular is involved in melanoma development. The aim of this study was to develop a new method enabling the determination of the pheomelanin in formalin-fixed paraffin-embedded (FFPE) tissue specimens of human nodular (NM) and superficial spreading (SSM) melanomas. The pheomelanin level was evaluated in a small amount of material obtained from FFPE melanoma samples (less than 1 mg), using a multi-step procedure of paraffin removal, tissue rehydration, and homogenisation, omitting the melanin isolation step. The obtained product was studied for pheomelanin content using the Py-GC/MS/MS method operating in a multiple reaction monitoring (MRM) mode. The results of our research confirmed the presence of all the pheomelanin markers in the FFPE human melanoma specimens and showed that the tissues analysed contained different amounts of pheomelanin isomers (5-S-cysteinylDOPA and 2-S-cysteinylDOPA). The developed Py-GC/MS/MS procedure enables sensitive quantification of pheomelanin in FFPE human melanoma samples, facilitating broader studies on its role in melanoma development and progression. This method opens new avenues for investigating pheomelanin’s involvement in melanoma malignancy. Full article

(This article belongs to the Special Issue Applications of Chromatographic Separation Techniques in Food and Chemistry—Second Edition)

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Graphical abstract

17 pages, 449 KiB

Open AccessFeature PaperArticle

New Functional Extruded Products Based on Corn and Lentil Flour Formulated with Winemaking By-Products

by Mario Cotacallapa-Sucapuca, José de J. Berrios, James Pan, Priscila Alves, Claudia Arribas, Mercedes M. Pedrosa, Patricia Morales and Montaña Cámara

Processes 2025, 13(6), 1635; https://doi.org/10.3390/pr13061635 - 22 May 2025

Abstract

To enhance the nutritional value of food products, new functional extruded products have been developed based on combinations of corn and lentil flour (70:30), with added salt (1.25%), sugar (5%), and resistant starch V (5–20%), and fortified winemaking by-products (fermented and unfermented pomace/pomace [...] Read more.

To enhance the nutritional value of food products, new functional extruded products have been developed based on combinations of corn and lentil flour (70:30), with added salt (1.25%), sugar (5%), and resistant starch V (5–20%), and fortified winemaking by-products (fermented and unfermented pomace/pomace seeds) (5–20%). The formulations were processed through a 32 mm twin screw extruder. The developed extrudates were analyzed for bioactive content. The findings show that among the experimental formulations, those with the highest concentration (20%) presented the greatest amounts of the following functional compound total dietary fiber, total arabinoxylans, resistant starch, total phenols, total flavonols, and total anthocyanins, and the lowest content of raffinose and stachyose. These study results indicate that extrusion is an effective method for adding value to underutilized commodities, such as winemaking by-products. A future sensory evaluation study will be conducted on the extruded products with the highest amount of winemaking by-products of 20%. Full article

(This article belongs to the Special Issue Feature Reviews in Food Processing Technologies: Present Innovations and Future Opportunities)

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17 pages, 9105 KiB

Open AccessArticle

The Law of Acid Pressure Fracture Propagation in Maokou Formation Carbonate Reservoir in Central Sichuan

by Yu Fan, Hailong Jiang, Zhouyang Wang, Jinsui Li, Xing Yang, Zefei Lv, Xiangfei Zhang and Xueyuan Han

Processes 2025, 13(6), 1634; https://doi.org/10.3390/pr13061634 - 22 May 2025

Abstract

The Dolomite reservoir of the Maokou Formation is rich in gas resources in the central Sichuan Basin. Acid fracturing is an important technical means to improve reservoir permeability and productivity. The interaction mode of the dolomite and limestone acid system will affect the [...] Read more.

The Dolomite reservoir of the Maokou Formation is rich in gas resources in the central Sichuan Basin. Acid fracturing is an important technical means to improve reservoir permeability and productivity. The interaction mode of the dolomite and limestone acid system will affect the effect of reservoir reconstruction. In order to clarify the influence of complex structure on fracture morphology, we explore the fracturing effect of different acid systems. Physical simulation experiments of true triaxial acid fracturing were carried out with two acid systems and downhole full-diameter cores. The experimental results show: (1) After the carbonate rock is subjected to acid fracturing using a “self-generated acid + gel acid” system, the fracture pressure drops significantly by up to 60%. The morphology of the acid-eroded fractures becomes more complex, with an increase in geometric complexity of about 28% compared to a single acid solution system. It is prone to form three-dimensional “spoon” shaped fractures, and the surface of the acid-eroded fractures shows light yellow acid erosion marks. Analysis of the acid erosion marks indicates that the erosion depth on the fracture surface reaches 0.8–1.2 mm, which is deeper than the 0.2 mm erosion depth achieved with a single system. (2) Acid solution is difficult to penetrate randomly distributed calcite veins with a low porosity and permeability structure. When the fracture meets the calcite vein, the penetration rate of acid solution drops sharply to 15–20% of the initial value, resulting in a reduction of about 62% of the acid erosion area in the limestone section behind. And the acid erosion traces in the limestone behind the calcite vein are significantly reduced. The acid erosion cracks are easy to open on the weak surface between dolomite and limestone, causing the fracture to turn. (3) The results of field engineering and experiment are consistent, and injecting authigenic acid first in the process of reservoir reconstruction is helpful to remove pollution. The recovery rate of near-well permeability is more than 85% with pre-generated acid. Reinjection of gelled acid can effectively communicate the natural weak surface and increase the complexity of cracks. The average daily oil production of the completed well was increased from 7.8 m³ to 22.5 m³, and the increase factor reached 2.88. Full article

(This article belongs to the Special Issue Environmentally Friendly Production of Energy from Natural Gas Hydrates)

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20 pages, 825 KiB

Open AccessArticle

A Hierarchical Distributed and Local Voltage Control Strategy for Photovoltaic Clusters in Distribution Networks

by Zhiwei Liu, Zhe Wang, Yuzhe Chen, Qirui Ren, Jinli Zhao, Sihai Qiu, Yuxiao Zhao and Hao Zhang

Processes 2025, 13(6), 1633; https://doi.org/10.3390/pr13061633 - 22 May 2025

Abstract

The increasing integration of distributed photovoltaics (PVs) has intensified voltage violations in active distribution networks (ADNs). Traditional centralized voltage regulation approaches face substantial challenges in terms of communication and computation. Distributed control methods can help mitigate these issues through distributed algorithms but struggle [...] Read more.

The increasing integration of distributed photovoltaics (PVs) has intensified voltage violations in active distribution networks (ADNs). Traditional centralized voltage regulation approaches face substantial challenges in terms of communication and computation. Distributed control methods can help mitigate these issues through distributed algorithms but struggle to track real-time fluctuations in PV generation. Local control offers fast voltage adjustments but lacks coordination among different PV units. This paper presents a hierarchical distributed and local voltage control strategy for PV clusters. First, the alternating direction method of multipliers (ADMM) algorithm is adopted to coordinate the reactive power outputs of PV inverters across clusters, providing reference values for local control. Then, in the local control phase, a Q-P control strategy is utilized to address real-time PV fluctuations. The flexibility of the local control strategy is enhanced using the lifted linear decision rule, enabling a rapid response to PV power fluctuations. Finally, the proposed strategy is tested on both the modified IEEE 33-node distribution system and a practical 53-node distribution system to evaluate its performance. The results demonstrate that the proposed method effectively mitigates voltage issues, reducing the average voltage deviation by 53.93% while improving flexibility and adaptability to real-time changes in PV output. Full article

(This article belongs to the Special Issue Distributed Intelligent Energy Systems)

17 pages, 1331 KiB

Open AccessArticle

A System Designed for Modelling, Monitoring, and Control of Fermentation Processes, Powered by Metaheuristic Algorithms

by Velislava Lyubenova, Dafina Zoteva, Maya Ignatova, Denitsa Kristeva and Olympia Roeva

Processes 2025, 13(6), 1632; https://doi.org/10.3390/pr13061632 - 22 May 2025

Abstract

This paper introduces an Interactive System for Education in Modelling and Control of Biotechnological Processes (InSEMCoBio) for biotechnologists, including students and researchers. The system integrates advanced optimisation algorithms for identifying models of nonlinear systems, along with algorithms for monitoring and controlling biotechnological processes. [...] Read more.

This paper introduces an Interactive System for Education in Modelling and Control of Biotechnological Processes (InSEMCoBio) for biotechnologists, including students and researchers. The system integrates advanced optimisation algorithms for identifying models of nonlinear systems, along with algorithms for monitoring and controlling biotechnological processes. InSEMCoBio was developed in MATLAB R2017a, featuring a user-friendly graphical interface that bridges complex computational tasks. Three metaheuristics for model identification are built in: an evolutionary algorithm, a genetic algorithm, and a hybrid metaheuristic algorithm. The software allows users to execute integrated algorithms and obtain desired results through visualisation (graphical and tabular) of data, without requiring programming knowledge. The functions of the system are demonstrated through the operation of the algorithms on two biotechnological processes. The ability to compare results of different algorithms is shown. The embedded identification algorithms are applicable beyond biotechnology. This provides the developed system with potential for other interesting applications. Full article

(This article belongs to the Section Process Control and Monitoring)

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21 pages, 4230 KiB

Open AccessArticle

A Study on the Crack Propagation Behavior of Cement Sheath Interfaces Considering Bond Strength

by Jiwei Wu, Xuegang Wang, Shiyuan Xie, Yanxian Wu, Yilin Li, Zhenhui Shu, Xiaojun Zhang, Wei Lian and Dandan Yuan

Processes 2025, 13(6), 1631; https://doi.org/10.3390/pr13061631 - 22 May 2025

Abstract

Existing studies have not considered the impact of interface bond strength on the ease of crack propagation at the cement sheath interface. Through Brazilian splitting and direct shear tests, the normal and shear bond strengths at interfaces I and II of a cement [...] Read more.

Existing studies have not considered the impact of interface bond strength on the ease of crack propagation at the cement sheath interface. Through Brazilian splitting and direct shear tests, the normal and shear bond strengths at interfaces I and II of a cement sheath were quantified. Based on this, a crack propagation model for the cement sheath interface was established using cohesive zone elements. The propagation characteristics of cracks along the axial and circumferential directions at interfaces I and II of a cement sheath during hydraulic fracturing were analyzed, along with their influencing factors. The results show that, due to the difference in interface bond strength, the crack propagation rate and length at interface I in the axial direction are greater than those at interface II, while the interface II crack is more likely to propagate in the circumferential direction. The elastic modulus of the cement sheath is a key factor affecting the integrity of the cement seal. Both excessively low and high elastic moduli can lead to different forms of failure in the cement sheath. It is recommended to control the elastic modulus of the cement sheath between 7 and 8 GPa. As the internal casing pressure increases, the axial propagation length of cement sheath interface cracks also increases. During fracturing, reducing pump pressure can reduce the axial crack propagation length in the cement sheath, alleviating or preventing the risk of fluid migration between stages and clusters. The findings of this study provide theoretical references and engineering support for the control of cement sheath seal integrity. Full article

(This article belongs to the Section Materials Processes)

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22 pages, 4552 KiB

Open AccessArticle

Wellhead Stability During Development Process of Hydrate Reservoir in the Northern South China Sea: Sensitivity Analysis

by Qingchao Li, Qiang Li, Jingjuan Wu, Kaige He, Yifan Xia, Junyi Liu, Fuling Wang and Yuanfang Cheng

Processes 2025, 13(6), 1630; https://doi.org/10.3390/pr13061630 - 22 May 2025

Abstract

Natural gas hydrates are a promising alternative energy source for oil and gas in the future. However, geomechanical issues, such as wellhead instability, may arise, affecting the safe and efficient development of hydrates. In the present work, a sensitivity analysis was performed on [...] Read more.

Natural gas hydrates are a promising alternative energy source for oil and gas in the future. However, geomechanical issues, such as wellhead instability, may arise, affecting the safe and efficient development of hydrates. In the present work, a sensitivity analysis was performed on sediment subsidence and wellhead instability during the development of marine hydrates using a multi-field coupled model. This is accomplished by adjusting the corresponding parameters based on the basic data of the default case. Meanwhile, the corresponding influencing mechanisms were explored. Finally, design recommendations for operation parameters were proposed based on the research findings regarding wellhead stability. It was found that the wellhead undergoes rapid sinking during a certain period in the early stage of hydrate development, followed by a slower, continued sinking. The sensitivity analysis found that when the depressurization amplitude is small, the wellhead sinking is also minimal. To maintain wellhead stability during the development process, it is recommended that neither the depressurization amplitude or drawdown pressure exceed 3.0 MPa. Although a high heating temperature can increase gas production to some extent, the accompanying excessive hydrate dissociation may compromise the stability of both the formation and wellhead. To balance gas production and wellhead stability, it is recommended that the heating amplitude does not exceed 50 °C. In addition, the permeability influences the distribution of pore pressure, which in turn affects sediment subsidence and wellbore stability. Wellhead stability deteriorates as permeability increases. Therefore, it is crucial to accurately determine the reservoir characteristics (such as permeability) before developing hydrates to avoid wellhead instability. Finally, the investigation results reveal that using different versions of the investigation model can impact the accuracy of the results, and neglecting certain physical fields may lead to an underestimation of the wellhead sinking. Full article

(This article belongs to the Special Issue Environmentally Friendly Production of Energy from Natural Gas Hydrates)

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31 pages, 1699 KiB

Open AccessFeature PaperReview

Downstream Processes in a Microalgae Biorefinery: Cascaded Enzymatic Hydrolysis and Pulsed Electric Field as Green Solution

by Gianpiero Pataro, Elham Eslami, Francesco Pignataro and Alessandra Procentese

Processes 2025, 13(6), 1629; https://doi.org/10.3390/pr13061629 - 22 May 2025

Abstract

Microalgae are a promising source of valuable compounds, including proteins, pigments, lipids, vitamins, and ingredients for cosmetics and animal feed. Despite their potential, downstream processing remains a major bottleneck in microalgae biorefineries, particularly in achieving high extraction efficiency with low energy and chemical [...] Read more.

Microalgae are a promising source of valuable compounds, including proteins, pigments, lipids, vitamins, and ingredients for cosmetics and animal feed. Despite their potential, downstream processing remains a major bottleneck in microalgae biorefineries, particularly in achieving high extraction efficiency with low energy and chemical input. While several extraction methods exist, few balance efficiency with selectivity and sustainability. Recently, mild and selective techniques such as Pulsed Electric Field (PEF) and Enzymatic Hydrolysis (EH) have gained attention, both individually and in combination. This review provides the first comprehensive comparative analysis of PEF and EH, emphasizing their mechanisms of action, specific cellular targets, and potential for integration into a cascaded, wet-route biorefinery process. Studies involving PEF, EH, and their sequential application (PEF-EH and EH-PEF) are analyzed, focusing on microalgae species, operational conditions, and extraction yields. The advantages and challenges of each method, including compound selectivity, environmental impact, and economic feasibility, are critically evaluated. The goal is to gain insight into whether the synergistic use of PEF and EH can enhance the recovery of intracellular compounds while improving the overall sustainability and efficiency of microalgae-based bioprocessing. Full article

(This article belongs to the Special Issue Process Intensification towards Sustainable Biorefineries)

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21 pages, 7194 KiB

Open AccessArticle

Rain-Resilient Image Restoration for Reliable and Sustainable Visual Monitoring in Industrial Inspection and Quality Control

by Miao Zhang, Shanqin Wang and Shiqun Yin

Processes 2025, 13(6), 1628; https://doi.org/10.3390/pr13061628 - 22 May 2025

Abstract

Reliable visual monitoring is essential for industrial quality control systems under adverse weather conditions. Rain-induced degradation, such as occlusions, texture blurring, and depth distortions, can significantly hinder image clarity and compromise precision in surface defect detection. To address this, we propose a novel [...] Read more.

Reliable visual monitoring is essential for industrial quality control systems under adverse weather conditions. Rain-induced degradation, such as occlusions, texture blurring, and depth distortions, can significantly hinder image clarity and compromise precision in surface defect detection. To address this, we propose a novel image deraining framework, the Degradation-Background Perception Network (DBPNet). DBPNet features a hierarchical encoder–decoder structure and incorporates two core modules: the Frequency Degradation Perception Module (FDPM) and the Depth Background Perception Module (DBPM). FDPM focuses on frequency decomposition to remove high-frequency rain streaks while retaining critical image features using cross-attention mechanisms. DBPM is proposed to integrate robust depth maps, which remain unaffected by rain degradation, as explicit constraints to guide the model in reconstructing clean scenes. Furthermore, we propose the Selective Focus Attention (SFA) module, which enhances interactions between frequency-domain features and background priors, ensuring accurate reconstruction and effective rain removal. Experimental results on five synthetic and real-world benchmark datasets demonstrate that our method outperforms state-of-the-art CNN and transformer-based approaches. This framework contributes to more robust visual input for process control, enabling better fault detection, predictive maintenance, and sustainable system operation. Full article

(This article belongs to the Section Process Control and Monitoring)

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