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process optimization of AlGaN high temperature reactor and multi-physicals calculation

MATERIALS SCIENCE IN SEMICONDUCTOR processING 2025年 192卷

作者： An, Jiadai Dai, Xianying Liu, Ying Huang, Kama Zhang, Dengke Zhoukou Normal Univ Sch Phys & Telecommun Engn Zhoukou 466000 Peoples R China Xidian Univ Sch Microelect Xian 710071 Peoples R China Xidian Univ Sch Elect Engn Xian 710071 Peoples R China Sichuan Univ Coll Elect & Informat Engn Chengdu 610065 Peoples R China Xidian Univ Sch Comp Sci & Technol Xian 710071 Peoples R China

Metal organic chemical vapor deposition (MOCVD) is a typical and effective approach to AlGaN thin film synthesize. High temperature is an effective mean to improve the crystallization quality. However, problems such as low efficiency, low yield and difficult process control are common in the growing process. Based on the consideration of operating pressure, gas flow rate and rotation speed, a high temperature reactor of AlGaN thin film MOCVD growth is proposed in this paper. The process parameters were optimized by CFD simulation, and multi-physicals such as temperature field, pressure field, velocity field and density field were calculated and analyzed by finite element method. The stability of the flow field in the reactor is realized, the parasitic reaction is effectively reduced, and the deposition efficiency and film quality are ensured. This research not only provides an effective scheme for high quality and efficient AlGaN synthesis, but also provides a theoretical basis for subsequent experiments and equipment improvement.

关键词： AlGaN HT-MOCVD process optimization Multi-physicals

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process optimization to maximize bonding performance of injection-moulded short-fibre composites

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COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING 2025年 193卷

作者： Verstraete, Sofie Serhat, Gokhan Debruyne, Stijn Desplentere, Frederik Katholieke Univ Leuven Dept Mat Engn ProPoliS Bruges CampusSpoorwegstr 12 B-8200 Brugge Belgium Katholieke Univ Leuven Dept Mech Engn M Grp Bruges CampusSpoorwegstr 12 B-8200 Brugge Belgium Katholieke Univ Leuven Dept Mech Engn Mechatron Syst Dynam LMSD Bruges CampusSpoorwegstr 12 B-8200 Brugge Belgium

Adhesive bonding has the major advantage of preserving structural integrity when joining laminated composites, whose stacking sequence influences the joint strength. For short fibre reinforced thermoplastics (SFRT), injection moulding process parameters such as the flow rate, wall temperature, and packing pressure directly affect the resulting fibre orientations. This study explores the fundamental effects of the fibre architecture in SFRT substrates on the stress distribution in single lap joints. Considering the observed influences, a metamodel-based optimization approach is proposed to improve the joint bonding performance by modifying the production process, where the maximization of the bending stiffness is selected as the primary performance indicator. Experimental results validate the introduced methodology as they revealed approximately 30 % average difference of between the lap shear strength levels of the samples with maximized and minimized bending stiffness. These findings highlight the importance of a well-controlled production procedure respecting the bonding area of SFRT composites.

关键词： Short fibre reinforced thermoplastics Injection moulding Adhesive bonding process optimization

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process optimization of refill friction spot stir of AA6061-T6 aluminum alloy for thick plate

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JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY 2025年第4期39卷 555-573页

作者： Di, Jiang Kolupaev, I. N. Wang, HongFeng Ge, Xiaole Huangshan Univ Coll Mech & Elect Engn Huangshan Anhui Peoples R China Natl Tech Univ Dept Mat Sci Kharkiv Polytech Inst Kharkiv Ukraine

To investigate the process parameters of refillable friction stir spot welding for AA6061-T6 aluminum alloy with a 3 mm plate thickness, and to extend the applicability of this technology, experiments were conducted using custom-made tools under varying rotational and penetration speeds. This study aimed to produce well-formed welds and analyze the metallurgical structure, tensile shear strength, and microhardness of the welded joints. The experiments were performed at rotational speeds of 1000, 1200, 1400, and 1600 rpm and penetration speeds of 20, 30, 40, and 50 mm/min. These conditions were found to facilitate effective refillable friction stir spot welding. The results indicated that at lower rotational speeds, the joints failed at the interface, while at higher speeds, failure occurred through the plug. Optimal tensile shear strength was achieved at a rotational speed of 1400 rpm and a penetration speed of 30 mm/min, with a peak force of 9.27 kN and a joint surface fracture mode. Microstructural examination revealed a significant refinement of grains in the weld zone compared to the base metal. Microhardness measurements showed a concentric ring pattern on the upper surface with higher hardness at the center, decreasing toward the edges. The cross-sectional hardness demonstrated a vertical gradient, being higher at the top and decreasing toward the bottom. Notably, the welded area exhibited signs of annealing with a reduced hardness compared to the base metal, where the maximum value was recorded as HV79.

关键词： Refill friction stir spot welding tensile and shear strength microhardness process optimization

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process optimization for Microstructure and Mechanical Properties Improvement of IN718 by Vacuum Centrifugal Casting

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INTERNATIONAL JOURNAL OF METALCASTING 2025年 1-18页

作者： Liao, Minle Jiang, Wenhao Ma, Xiaoqing Li, Tianxiang Liu, Guohuai Wang, Zhaodong Northeastern Univ State Key Lab Rolling & Automat Shenyang 110819 Peoples R China Liaoning Petrochem Univ Sch Mech Engn Fushun 113001 Liaoning Peoples R China Henan Acad Sci Inst Mat Zhengzhou 450046 Peoples R China

Large IN718 rings were first fabricated using vacuum centrifugal casting, overcoming the challenges of conventional processes, including low material utilization, high-energy consumption, and long production cycles. This study synergized numerical simulations, regression modeling, and optimization algorithms to optimize the casting process and elucidate the layered solidification behavior. Validated computational models coupled with partial least squares regression (PLSR) quantified the correlations between process parameters and key microstructural features, including grain size, macroshrinkage porosity, and microshrinkage porosity. Subsequent optimization of the PLSR-derived constitutive relationships was achieved through implementation of the dung beetle optimizer algorithm. Comparative experiments validated the effectiveness of the optimized parameters achieved through the optimization algorithm. The results showed that the grain size of cast ring reduced from 74 to 56 mu m, and the microshrinkage porosity diminished from grade 4-2. The optimized process parameters facilitated solidification by layer and rapid cooling during the centrifugal casting process, with temperature fields and flow dynamics acting as critical latent variables bridging process parameters and microstructural characteristics. The optimized IN718 rings exhibited superior ductility (22.1% elongation), demonstrating excellent compatibility with diverse downstream processing routes.

关键词： process optimization IN718 alloy vacuum centrifugal casting numerical simulation microstructural optimization strength and ductility enhancing

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process optimization and bioflocculative insights of glycoprotein bioflocculant produced by marine bacterium Bacillus oceanisediminis LBB1

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BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2025年 65卷

作者： Cherian, Tijo Eranhottu, Shibin Mohanraju, R. Pondicherry Univ Dept Ocean Studies & Marine Biol Port Blair Campus Andamans 744112 India

A type of environmentally benign and biodegradable biopolymers made by different microorganisms, bioflocculants have drawn more attention as viable substitutes for traditional chemical flocculants in the treatment of wastewater and the removal of pollutants. However, a number of obstacles prevent bioflocculants from being scaled up industrially, such as expensive substrate prices, limited manufacturing yields, and complex purifying procedures. A careful consideration must be given to the potential of microbiological contamination and the resulting health consequences linked to the use of bioflocculants. In present study, the bio-flocculative activity of Bacillus oceanisediminis LBB1 isolated from the gut of a finfish Lutjanus biguttanus, has been documented for the first time-the glycoproteinaceous bioflocculant BOB1 found to be an excellent bioflocculant with 80 % flocculating activity. The process standardization and optimization elucidated the most feasible and favourable reaction conditions ascertaining the synthesis and reaction kinetics of the bioflocculant BOB1 against kaolin clay suspension. The pattern of thermal stability of BOB1 was found to be fairly steady and stable with the maximal value reaching 94.6 % +/- 1.0 % at 30 degrees C. The presence of various functional groups was analysed by FT-IR whereas the SEM micrographs exhibited the compact nature and fine and scattered particles of BOB-1. Hence, the creation of multipurpose flocculants based on MBF and its cooperative use with other treatment technologies are recognized as new developments for improved resource recovery and wastewater treatment.

关键词： Bacillus oceanisediminis Bioflocculant process optimization Water treatment

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Vacuum ammonia stripping from liquid digestate:Effects of pH,alkalinity,temperature,negative pressure and process optimization

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Journal of Environmental Sciences 2025年第3期149卷 638-650页

作者： Qiuhong Chen Donghai Yang Xiang Chen Xiankai Wang Bin Dong Xiaohu Dai State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China YANGTZE Eco-Environment Engineering Research Center National Engineering Research Center of Eco-environment Protection for Yangtze River Economic BeltChina Three Gorges CorporationWuhan 430010China

High ammonia-nitrogen digestate has become a key bottleneck limiting the anaerobic digestion of organic solid *** ammonia stripping can simultaneously remove and recover ammonia nitrogen,which has attracted a lot of attention in recent *** investigate the parameter effects on the efficiency and mass transfer,five combination conditions(53℃ 15 kPa,60°C 20 kPa,65°C 25 kPa,72°C 35 kPa,and 81°C 50 kPa)were conducted for ammonia stripping of sludge *** results showed that 80%of ammonia nitrogen was stripped in 45 min for all experimental groups,but the ammonia transfer coefficient varied under different conditions,which increased with the rising of boiling point temperature,and reached the maximum value(39.0 mm/hr)at 81°C 50 *** ammonia nitrogen removal efficiency was more than 80%for 30 min vacuum stripping after adjusting the initial pH to above 9.5,and adjustment of the initial alkalinity also affects the pH value of liquid *** was found that pH and alkalinity are the key factors influencing the ammonia nitrogen dissociation and removal efficiency,while temperature and vacuum mainly affect the ammonia nitrogen mass transfer and removal *** terms of the mechanism of vacuum ammonia stripping,it underwent alkalinity destruction,pH enhancement,ammonia nitrogen dissociation,and free ammonia *** this study,two-stage experiments of alkalinity destruction and ammonia removal were also carried out,which showed that the two-stage configuration was beneficial for ammonia *** provides a theoretical basis and practical technology for the vacuum ammonia stripping from liquid digestate of organic solid waste.

关键词： Liquid digestate Vacuum ammonia stripping Alkalinity Mass transfer process optimization

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Investigation on the modeling and simulation of hydrodynamics in asymmetric conduction laser micro-welding of austenitic stainless steel and its process optimization

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE 2025年第4期239卷 530-543页

作者： de la Hoz, Jose Luis Velazquez Cheng, Kai Brunel Univ London Coll Engn Design & Phys Sci Uxbridge England Brunel Univ London Coll Engn Design & Phys Sci Mech & Automot Engn Dept Uxbridge UB8 3PH Middx England

Laser micro-welding is a joining technology utilized across various high-value industries, like medical, automotive, e-mobility, and aerospace. A trial-and-error process to identify welding parameters does not necessarily lead to optimized quality levels. Furthermore, offline non-destructive examination methods often launched to verify welding quality may inadvertently trigger excessive costs and time delays, ultimately failing to guarantee defect-free welds. In response to these challenges, this article introduces an advanced multiscale model designed to unravel the intricate dynamics of hydrodynamics and the overarching physics within laser micro-welding melting pools. Developed using the COMSOL software package, the model adeptly demonstrates how surface tension gradients shape the geometry of welds, thus influencing their quality. This knowledge allows the mapping of welding defects. One of the novelties of the article is to introduce geometric dissimilar welding conditions by simulating an asymmetric edge joint. It shows a study on a new, unstudied way to laser weld with many applications in the field. The model further establishes its utility in design experiments to determine parameter, tolerance, and system design. Moreover, the insights garnered from understanding and controlling these drivers have far-reaching implications for the advancement of subsequent methodological research and the development of in-situ quality control practices by characterizing the welding defects. Finally, the results shows that the discouragingly high computational costs restrict its potential application to support a Digital Twin.

关键词： Asymmetric laser micro welding melt hydrodynamics multiphysics modeling and simulation smart manufacturing process optimization laser conduction regime multiscale modeling multiphysics simulation Digital Twin

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Home Biogas Production from Organic Waste: Challenges and process optimization of Methane Fermentation

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ENERGIES 2025年第7期18卷 1745-1745页

作者： Holewa-Rataj, Jadwiga Rataj, Mateusz Kapusta, Piotr Brzeszcz, Joanna Janiga, Marek Krol, Anna Natl Res Inst Oil & Gas Inst Ul Lubicz 25a PL-31503 Krakow Poland

This publication presents an analysis of the possibilities for home biogas production using an original method. The assumptions for a biogas-generating system and key principles for the methane fermentation process are outlined. Research on the methane fermentation of both kitchen waste and green waste was conducted using a methanogenic consortium. The studies allowed for the characterization of the microorganisms comprising the consortium, and tests confirmed the feasibility of conducting methane fermentation of both types of waste at both laboratory and technical scales, as well as estimating the biogas productivity of the substrates. Based on the research conducted at both scales, the range of conditions under which the biogas production process is possible was determined, with particular reference to temperature conditions and the pH of the leachate. The tests, primarily conducted at a technical scale, allowed for the definition and implementation of optimization measures that resulted in increased process efficiency at the technical scale. Among the main optimization measures were the use of sand as a phase to maintain an anaerobic zone at the start of the process, the use of wood ash to stabilize pH, and the use of substrates and water at room temperature.

关键词： biogas production methane fermentation waste substrates process optimization household waste household fermenters

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BDD electrode pulsed alternating electrochemical oxidation of sulfamethazine in antibiotic wastewater: process optimization and degradation mechanism

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ENVIRONMENTAL RESEARCH 2025年 275卷 121375页

作者： Hu, Simeng Lv, Yongshang Hou, Xifei Li, Jiahao Hou, Yaxuan Fu, Xiaohua Xu, Tao Cent South Univ Forestry & Technol Coll Chem & Chem Engn Changsha 410004 Peoples R China Hunan Univ Coll Chem & Chem Engn Changsha 410082 Peoples R China Cent South Univ Forestry & Technol Coll Life & Environm Sci Changsha 410004 Peoples R China Cent South Univ Forestry & Technol Coll Mat Sci & Engn Changsha 410004 Peoples R China

To address the issues of electrode passivation and high electric energy consumption (EEC) associated with the removal of antibiotic wastewater using traditional direct current electrocatalytic oxidation (DCEO) with BoronDoped Diamond (BDD) electrodes, this study aims to develop an efficient, low-cost, and self-cleaning BDD electrode pulsed alternating electrocatalytic oxidation (BDD-PAEO) technology. The experimental findings demonstrated that, under optimal conditions, the BDD-PAEO mode achieved a 99.9% removal efficiency for sulfamethazine (SMZ). Furthermore, the removal efficiency of COD in the BDD-PAEO mode consistently remained above 93% in 10 experimental cycles. Compared with the BDD-DCEO mode, the EEC of the BDD-PAEO mode is reduced by 17.39%, and the current efficiency (CE) is increased by 47.15%. The & sdot;OH was confirmed to be the main active oxidant species for degradation of SMZ by free radical quenching experiments, electron paramagnetic resonance (EPR) and three-dimensional excitation-emission matrix (3D-EEM) spectroscopy. The degradation pathway of SMZ was revealed by density functional theory (DFT) calculation and gas chromatography-mass spectrometry (GC-MS) analysis. Toxicity estimation illustrated that BDD-PAEO technology can effectively reduce the toxicity of wastewater after SMZ degradation. This study shows BDD-PAEO technology's high potential for efficient SMZ degradation and toxicity reduction in antibiotic wastewater, offering a novel treatment solution.

关键词： BDD electrode Pulsed alternating electrocatalytic oxidation Sulfamethazine process optimization Degradation mechanism

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Synergistic recycling of ground granulated blast furnace slag-red mud-phosphogypsum for developing low-carbon composite cementitious material: Performance characterization and process optimization

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CONSTRUCTION AND BUILDING MATERIALS 2025年 473卷

作者： Sun, Chuanbo Chen, Xin Lu, Longzhao Yi, Fu Li, Jiang-shan Liaoning Tech Univ Sch Civil Engn Fuxin 123000 Liaoning Peoples R China Chinese Acad Sci Inst Rock & Soil Mech State Key Lab Geomech & Geotech Engn Safety Wuhan 430071 Peoples R China IRSM CAS HK PolyU Joint Lab Solid Waste Sci Wuhan 430071 Peoples R China

A low-carbon composite cementitious material based on all-solid wastes was developed by synergistically utilizing ground granulated blast furnace slag (GGBS), red mud (RM), and phosphogypsum (PG). By adjusting the material proportions, the relationships between water demand for standard consistency, setting time, flowability, soundness, and mechanical properties of the composite material were explored. The hydration products, microstructure, and heavy metal leaching risks of the composite materials at different ratios were also investigated. The results demonstrate that the incorporation of RM increased the water demand for standard consistency, while the addition of PG had a retarding effect on the paste. The produced material exhibited excellent soundness and workability. The GGBS-PG system showed stronger hydration synergy compared to the GGBS-RM system. When the mass ratio of MGGBS: MRM: MPG was 6:2:2, the unconfined compressive strength (UCS) of the composite cementitious material reached a maximum of 30.86 MPa after 28 days of curing. The (N, C)-A-S-H structure at this ratio exhibited the highest degree of polymerization for H-O-H and Si-O-Al groups, and meanwhile the ettringite (AFt) began to turn into monosulfoaluminate (Ms). As a low-carbon composite cementitious material with controllable strength, the GGBS-RM-PG ternary composite material presents an environmentally friendly alternative to traditional cement-based materials.

关键词： Ground granulated blast furnace slag Red mud Phosphogypsum Low-carbon composite cementitious material process optimization

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