Pub Date : 2025-02-10DOI: 10.1016/j.partic.2025.01.006
Andrea Dernbecher , Supriya Bhaskaran , Nicole Vorhauer-Huget , Jakob Seidenbecher , Suresh Gopalkrishna , Lucas Briest , Alba Dieguez-Alonso
In the present study, the influence of the dynamic and anistropic pore microstructure of wood and char samples on the intra-particle flow permeability and tortuosity was investigated. To this end, a beech wood sphere was pyrolysed at different temperatures (100 °C, 200 °C, 300 °C, 400 °C, and 500 °C) and characterised, after each pyrolysis step, by X-ray micro-computed tomography (μ-CT). From the μ-CT images, the structural geometry of the particle at the different conversion degrees achieved at each temperature level was extracted. The porosity evolution was characterised, accounting for pores larger than 15 μm, which was the limit of resolution for μ-CT imaging in this study. The structural geometry was divided in subdomains and used for CFD (computational fluid dynamics) simulations, where the pressure loss at different velocities and in different directions with respect to the main pores (vessel cells) was determined and used to estimate the dynamic and anisotropic permeabilities. The permeability differed by an order of magnitude in the direction of the main pores (vessel cells) in comparison to the perpendicular directions, supporting the need to develop permeability tensors for improved simulations of the pyrolysis process at particle level, accounting for the coupled effects of microstructure, transport, and reaction.
{"title":"Investigation on the intra-particle anisotropic transport properties of a beech wood particle during pyrolysis","authors":"Andrea Dernbecher , Supriya Bhaskaran , Nicole Vorhauer-Huget , Jakob Seidenbecher , Suresh Gopalkrishna , Lucas Briest , Alba Dieguez-Alonso","doi":"10.1016/j.partic.2025.01.006","DOIUrl":"10.1016/j.partic.2025.01.006","url":null,"abstract":"<div><div>In the present study, the influence of the dynamic and anistropic pore microstructure of wood and char samples on the intra-particle flow permeability and tortuosity was investigated. To this end, a beech wood sphere was pyrolysed at different temperatures (100 °C, 200 °C, 300 °C, 400 °C, and 500 °C) and characterised, after each pyrolysis step, by X-ray micro-computed tomography (μ-CT). From the μ-CT images, the structural geometry of the particle at the different conversion degrees achieved at each temperature level was extracted. The porosity evolution was characterised, accounting for pores larger than 15 μm, which was the limit of resolution for μ-CT imaging in this study. The structural geometry was divided in subdomains and used for CFD (computational fluid dynamics) simulations, where the pressure loss at different velocities and in different directions with respect to the main pores (vessel cells) was determined and used to estimate the dynamic and anisotropic permeabilities. The permeability differed by an order of magnitude in the direction of the main pores (vessel cells) in comparison to the perpendicular directions, supporting the need to develop permeability tensors for improved simulations of the pyrolysis process at particle level, accounting for the coupled effects of microstructure, transport, and reaction.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"98 ","pages":"Pages 172-190"},"PeriodicalIF":4.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-09DOI: 10.1016/j.partic.2025.01.007
Zhipeng Wang , Yuhang Jiang , Yaonan Zhu , Feng Ma , Youzhao Wang , Chaoyue Zhao , Xu Li , Tong Zhu
To facilitate the recycling of polluted soils, the development of innovative multi-axial soil remediation machinery is essential for achieving a uniform blend of soil with remediation chemicals. The mean level of the steepest climb test was set using the mean level derived from the orthogonal test, and then the range of optimum values was determined based on the results of the steepest climb test, and the upper and lower bound intervals of the response surface test were set accordingly. The most optimal model is identified by applying machine learning algorithms to the response surface data. The results show that the Decision Tree model outperforms Random Forest, SVR, KNN and XG Boost in terms of accuracy and stability in predicting dual indicators. Analysis of the decision tree model yields the following optimal parameter settings: homogenisation time of 1.7 s, homogenisation spacing of 181 mm, crusher spacing of 156 mm, and speed of 113 rpm. In the final test prototype, the error rates of the machine learning prediction models were 3.01% and 3.88% respectively. The experimental data confirms that the prediction accuracy reaches a satisfactory level after applying machine learning to optimise the parameters. This study will provide a reference for the design and optimisation of new in situ multi-axial soil remediation devices.
{"title":"Prediction and validation of parameters of multi-axis soil remediation equipment based on machine learning algorithms","authors":"Zhipeng Wang , Yuhang Jiang , Yaonan Zhu , Feng Ma , Youzhao Wang , Chaoyue Zhao , Xu Li , Tong Zhu","doi":"10.1016/j.partic.2025.01.007","DOIUrl":"10.1016/j.partic.2025.01.007","url":null,"abstract":"<div><div>To facilitate the recycling of polluted soils, the development of innovative multi-axial soil remediation machinery is essential for achieving a uniform blend of soil with remediation chemicals. The mean level of the steepest climb test was set using the mean level derived from the orthogonal test, and then the range of optimum values was determined based on the results of the steepest climb test, and the upper and lower bound intervals of the response surface test were set accordingly. The most optimal model is identified by applying machine learning algorithms to the response surface data. The results show that the Decision Tree model outperforms Random Forest, SVR, KNN and XG Boost in terms of accuracy and stability in predicting dual indicators. Analysis of the decision tree model yields the following optimal parameter settings: homogenisation time of 1.7 s, homogenisation spacing of 181 mm, crusher spacing of 156 mm, and speed of 113 rpm. In the final test prototype, the error rates of the machine learning prediction models were 3.01% and 3.88% respectively. The experimental data confirms that the prediction accuracy reaches a satisfactory level after applying machine learning to optimise the parameters. This study will provide a reference for the design and optimisation of new in situ multi-axial soil remediation devices.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"98 ","pages":"Pages 41-55"},"PeriodicalIF":4.1,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-08DOI: 10.1016/j.partic.2025.01.008
Yunfei Yan , Haixia Zhang , Junrong Yue , Yu Guan , Lei Shao
Barium titanate (BaTiO3) is an important ferroelectric and electronic ceramic material because of its outstanding dielectric and ferroelectric properties. The demand for BaTiO3 nanoparticles with adjustable particle size has increased extensively due to the miniaturization of electronic devices. The oxalate precipitation method is regarded as a highly attractive technology for fabricating BaTiO3 nanoparticles, as it enables large-scale production at a low cost. However, the calcination process is a crucial step that significantly influences the particle size and morphology of the obtained BaTiO3 nanoparticles. This study investigates the thermal decomposition mechanism and particle size regulation strategies during the calcination of barium titanyl oxalate tetrahydrate (BTOT) for fabricating BaTiO3 nanoparticles. The Kissinger-Akahira-Sunose (KAS) model is used to calculate the kinetic parameters of BTOT thermal decomposition process, and the results indicate that the decomposition process can be divided as four stages, with the average activation energy of 60.77, 269.89, 484.72, and 199.82 kJ/mol, respectively. The average activation energy reaches its maximum value in the third stage, indicating that the thermal decomposition reaction in this stage is more challenging to occur compared to the other stages. The gas release behaviors of H₂O, CO, and CO2 are analyzed on-line during the thermal decomposition of BTOT, and the overall reaction mechanism is proposed. Additionally, by adjusting the calcination parameters, the particle size of BaTiO3 could be effectively regulated within the range of 25–120 nm. Increasing the heating rate from 10 to 40 K/min decreases the average particle size of BaTiO3 from 62 to 44 nm. Extending the calcination time from 0 to 120 min increases the average particle size from 25 to 71 nm. Raising the terminal temperature from 1173 to 1273 K significantly increases the average particle size from 56 to 120 nm. Briefly, accelerating the heating rate, reducing the calcination time, and lowering the calcination temperature facilitate the fabrication of BaTiO3 with a smaller particle size and more uniform morphology. This study offers a robust theoretical framework and technical guidance for optimizing the process conditions for fabricating BaTiO3 nanoparticles via controlled thermal decomposition of BTOT, while also contributing to the advancement of related technological fields.
{"title":"Thermal decomposition mechanism and particle size regulation in calcination of barium titanyl oxalate tetrahydrate for fabricating barium titanate nanoparticles","authors":"Yunfei Yan , Haixia Zhang , Junrong Yue , Yu Guan , Lei Shao","doi":"10.1016/j.partic.2025.01.008","DOIUrl":"10.1016/j.partic.2025.01.008","url":null,"abstract":"<div><div>Barium titanate (BaTiO<sub>3</sub>) is an important ferroelectric and electronic ceramic material because of its outstanding dielectric and ferroelectric properties. The demand for BaTiO<sub>3</sub> nanoparticles with adjustable particle size has increased extensively due to the miniaturization of electronic devices. The oxalate precipitation method is regarded as a highly attractive technology for fabricating BaTiO<sub>3</sub> nanoparticles, as it enables large-scale production at a low cost. However, the calcination process is a crucial step that significantly influences the particle size and morphology of the obtained BaTiO<sub>3</sub> nanoparticles. This study investigates the thermal decomposition mechanism and particle size regulation strategies during the calcination of barium titanyl oxalate tetrahydrate (BTOT) for fabricating BaTiO<sub>3</sub> nanoparticles. The Kissinger-Akahira-Sunose (KAS) model is used to calculate the kinetic parameters of BTOT thermal decomposition process, and the results indicate that the decomposition process can be divided as four stages, with the average activation energy of 60.77, 269.89, 484.72, and 199.82 kJ/mol, respectively. The average activation energy reaches its maximum value in the third stage, indicating that the thermal decomposition reaction in this stage is more challenging to occur compared to the other stages. The gas release behaviors of H₂O, CO, and CO<sub>2</sub> are analyzed on-line during the thermal decomposition of BTOT, and the overall reaction mechanism is proposed. Additionally, by adjusting the calcination parameters, the particle size of BaTiO<sub>3</sub> could be effectively regulated within the range of 25–120 nm. Increasing the heating rate from 10 to 40 K/min decreases the average particle size of BaTiO<sub>3</sub> from 62 to 44 nm. Extending the calcination time from 0 to 120 min increases the average particle size from 25 to 71 nm. Raising the terminal temperature from 1173 to 1273 K significantly increases the average particle size from 56 to 120 nm. Briefly, accelerating the heating rate, reducing the calcination time, and lowering the calcination temperature facilitate the fabrication of BaTiO<sub>3</sub> with a smaller particle size and more uniform morphology. This study offers a robust theoretical framework and technical guidance for optimizing the process conditions for fabricating BaTiO<sub>3</sub> nanoparticles via controlled thermal decomposition of BTOT, while also contributing to the advancement of related technological fields.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"98 ","pages":"Pages 94-104"},"PeriodicalIF":4.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-08DOI: 10.1016/j.partic.2025.01.010
Babar Azeem
Controlled-release coated urea (CRCU) is an important agrochemical in precision farming, with its effectiveness reliant on the quality of the coating film and the nutrient-release kinetics. This study explores the use of a chemically modified lignocellulosic biopolymer derived from almond shells as a coating material for producing CRCU using Wurster fluidized-bed equipment. The study examines how process parameters—namely fluidized-bed temperature (Tfb), spray rate (Rspray), fluidizing-air flow rate (Qair), and atomizing-air pressure (Pair)—influence coating quality and nutrient-release kinetics. These are assessed through the inter-particle coefficient of coating mass variance (CMV) and the diffusion coefficient, respectively. The mechanism of nutrient release was studied using the Ritger and Peppas empirical model, specifically by calculating the diffusional exponent, n, for all samples. A Response Surface Methodology (RSM) approach coupled with a CCRD was applied to plan the experiments, perform statistical analysis, predict outcomes, and optimize the process conditions. The Analysis of Variance indicated that Tfb significantly impacts the studied parameters. Optimal coating quality (CMV = 6.7%) was achieved under conditions of Tfb = 75 °C, Qair = 80 m³/h, Rspray = 0.17 mL/s, and Pair = 3.1 bar. The optimum diffusion coefficient (2.2 × 10⁻⁷ cm2/s) was obtained at Tfb = 78 °C, Qair = 75 m³/h, Rspray = 0.125 mL/s, and Pair = 3.2 bar. The experimental and predicted responses showed close agreement that validates the regression models for predicting quality of coating films and kinetics of nutrient-release. Based on the n values, some samples exhibited Fickian diffusion, while others followed a non-Fickian nutrient-release mechanism.
{"title":"Effect of process parameters on coating mass variability and nitrogen-release kinetics of controlled-release urea granules produced in a Wurster fluidized-bed","authors":"Babar Azeem","doi":"10.1016/j.partic.2025.01.010","DOIUrl":"10.1016/j.partic.2025.01.010","url":null,"abstract":"<div><div>Controlled-release coated urea (CRCU) is an important agrochemical in precision farming, with its effectiveness reliant on the quality of the coating film and the nutrient-release kinetics. This study explores the use of a chemically modified lignocellulosic biopolymer derived from almond shells as a coating material for producing CRCU using Wurster fluidized-bed equipment. The study examines how process parameters—namely fluidized-bed temperature (<em>T</em><sub><em>fb</em></sub>), spray rate (<em>R</em><sub><em>spray</em></sub>), fluidizing-air flow rate (<em>Q</em><sub><em>air</em></sub>), and atomizing-air pressure (<em>P</em><sub><em>air</em></sub>)—influence coating quality and nutrient-release kinetics. These are assessed through the inter-particle coefficient of coating mass variance (CMV) and the diffusion coefficient, respectively. The mechanism of nutrient release was studied using the Ritger and Peppas empirical model, specifically by calculating the diffusional exponent, <em>n</em>, for all samples. A Response Surface Methodology (RSM) approach coupled with a CCRD was applied to plan the experiments, perform statistical analysis, predict outcomes, and optimize the process conditions. The Analysis of Variance indicated that <em>T</em><sub><em>fb</em></sub> significantly impacts the studied parameters. Optimal coating quality (CMV = 6.7%) was achieved under conditions of <em>T</em><sub><em>fb</em></sub> = 75 °C, <em>Q</em><sub><em>air</em></sub> = 80 m³/h, <em>R</em><sub><em>spray</em></sub> = 0.17 mL/s, and <em>P</em><sub><em>air</em></sub> = 3.1 bar. The optimum diffusion coefficient (2.2 × 10⁻⁷ cm<sup>2</sup>/s) was obtained at <em>T</em><sub><em>fb</em></sub> = 78 °C, <em>Q</em><sub><em>air</em></sub> = 75 m³/h, <em>R</em><sub><em>spray</em></sub> = 0.125 mL/s, and <em>P</em><sub><em>air</em></sub> = 3.2 bar. The experimental and predicted responses showed close agreement that validates the regression models for predicting quality of coating films and kinetics of nutrient-release. Based on the <em>n</em> values, some samples exhibited Fickian diffusion, while others followed a non-Fickian nutrient-release mechanism.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"98 ","pages":"Pages 67-82"},"PeriodicalIF":4.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Characterizing the hydrodynamics of a fluidized bed flotation column is essential for understanding the behavior of this multiphase flow system. Bed pressure fluctuations and phase hold-ups are two of these key characteristics. Static bed height effects on these two key characteristics were comprehensively studied using experimental and statistical analysis operating for different flow regimes. And three different bed height-to-diameter ratios (H/D = 1.0, 1.5, and 2.0) were investigated. The time series signals of pressure fluctuation were recorded via a pressure transducer, then analyzed through time and frequency domain methods. Cross-sectional and radial combined gas and solid hold-ups distribution were detected through the electrical resistance tomography under different H/D ratios. Results indicated that the key parameters of bed pressure fluctuation signals and gas-solid hold-up distributions are significantly affected by the change in static bed height, which can be explained by differences in bubble dynamics and particle movement behaviors.
{"title":"Effects of static bed height on pressure fluctuations and phase hold-ups in fluidized bed flotation column","authors":"Jincheng Liu , Mengdi Xu , Yaowen Xing , Xiahui Gui","doi":"10.1016/j.partic.2025.01.009","DOIUrl":"10.1016/j.partic.2025.01.009","url":null,"abstract":"<div><div>Characterizing the hydrodynamics of a fluidized bed flotation column is essential for understanding the behavior of this multiphase flow system. Bed pressure fluctuations and phase hold-ups are two of these key characteristics. Static bed height effects on these two key characteristics were comprehensively studied using experimental and statistical analysis operating for different flow regimes. And three different bed height-to-diameter ratios (<em>H</em>/<em>D</em> = 1.0, 1.5, and 2.0) were investigated. The time series signals of pressure fluctuation were recorded via a pressure transducer, then analyzed through time and frequency domain methods. Cross-sectional and radial combined gas and solid hold-ups distribution were detected through the electrical resistance tomography under different <em>H</em>/<em>D</em> ratios. Results indicated that the key parameters of bed pressure fluctuation signals and gas-solid hold-up distributions are significantly affected by the change in static bed height, which can be explained by differences in bubble dynamics and particle movement behaviors.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"98 ","pages":"Pages 56-66"},"PeriodicalIF":4.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-07DOI: 10.1016/j.partic.2025.01.005
Ruihan Zhuang , Jionglong Zhang , Gang Chen , Zhibin Wang , Lisi Jia , Ying Chen
Particle focusing, which organizes randomly dispersed particles into streamlines, is crucial for particle counting, enrichment, and detection. This process is widely applied in disease diagnosis, biochemical testing, and environmental monitoring. We designed a curved microchannel featuring integrated rectangular expansion-contraction arrays on its inner side. Our design diverges from conventional techniques by harnessing the synergistical effect of Dean flow induced by both structures based on the unique geometric configuration, resulting in a marked improvement in particle focusing efficiency. We validated the focusing performance of the combined microchannel and elucidated inertial focusing mechanisms by integrating experiments with simulations. At a Reynolds number of 83.33, a 4.34-cm-long microchannel can achieve the complete focusing of 10-μm particles, representing an advancement over current designs. Furthermore, our research uncovers a novel observation: the focusing width initially decreases with the expansion region's width and then increases, while the length of the expansion region leads to a gradual decrease in focusing width until it reaches a stable point. Through structural optimization, the dimensionless focusing width of 10-μm particles was reduced from 0.102 to 0.065 at a Reynolds number of 50, and particles of 5 and 15 μm can be completely focused, highlighting its adaptability and exceptional performance across a range of particle sizes. This study not only advances the un1derstanding of particle focusing dynamics but also paves the way for the development of more efficient and versatile microfluidic devices for a multitude of applications.
{"title":"Synergistically enhancing inertial particle focusing using a curved microchannel with expansion-contraction arrays","authors":"Ruihan Zhuang , Jionglong Zhang , Gang Chen , Zhibin Wang , Lisi Jia , Ying Chen","doi":"10.1016/j.partic.2025.01.005","DOIUrl":"10.1016/j.partic.2025.01.005","url":null,"abstract":"<div><div>Particle focusing, which organizes randomly dispersed particles into streamlines, is crucial for particle counting, enrichment, and detection. This process is widely applied in disease diagnosis, biochemical testing, and environmental monitoring. We designed a curved microchannel featuring integrated rectangular expansion-contraction arrays on its inner side. Our design diverges from conventional techniques by harnessing the synergistical effect of Dean flow induced by both structures based on the unique geometric configuration, resulting in a marked improvement in particle focusing efficiency. We validated the focusing performance of the combined microchannel and elucidated inertial focusing mechanisms by integrating experiments with simulations. At a Reynolds number of 83.33, a 4.34-cm-long microchannel can achieve the complete focusing of 10-μm particles, representing an advancement over current designs. Furthermore, our research uncovers a novel observation: the focusing width initially decreases with the expansion region's width and then increases, while the length of the expansion region leads to a gradual decrease in focusing width until it reaches a stable point. Through structural optimization, the dimensionless focusing width of 10-μm particles was reduced from 0.102 to 0.065 at a Reynolds number of 50, and particles of 5 and 15 μm can be completely focused, highlighting its adaptability and exceptional performance across a range of particle sizes. This study not only advances the un1derstanding of particle focusing dynamics but also paves the way for the development of more efficient and versatile microfluidic devices for a multitude of applications.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"98 ","pages":"Pages 83-93"},"PeriodicalIF":4.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.partic.2024.12.006
Tauseeq Hussain , Atta Ullah , Rehan Zubair Khalid , Farooq Ahmad , Fei Li , Asifullah Khan
Non-spherical particles are extensively encountered in the process industry such as feedstock or catalysts e.g., energy, food, pharmaceuticals, and chemicals. The design of equipment used to process these particles is highly dependent upon the accurate and reliable modeling of hydrodynamics of particulate media involved. Drag coefficient of these particles is the most significant of all parameters. A universal model to predict the drag coefficient of such particles has not yet been developed due to the diversity and complexity of particle shapes and sizes. Taking this into consideration, we propose a unique approach to model the drag coefficient of non-spherical particles using machine learning (ML) to move towards generalization. A comprehensive database of approximately five thousand data points from reliable experiments and high-resolution simulations was compiled, covering a wide range of conditions. The drag coefficient was modeled as a function of Reynolds number, sphericity, Corey Shape Factor, aspect ratio, volume fraction, and angle of incidence. Three ML techniques—Artificial Neural Networks, Random Forest, and AdaBoost—were used to train the models. All models demonstrated strong generalization when tested on unseen data. However, AdaBoost outperformed the others with the lowest MAPE (20.1%) and MRD (0.069). Additional analysis on excluded data confirmed the robust predictive abilities and generalization of the proposed model. The models were also evaluated across three flow regimes—Stokes, transitional, and turbulent—to further assess their generalization. A comparative analysis with well-known empirical correlations, such as Haider and Levenspiel and Chien, showed that all ML models outperformed traditional approaches, with AdaBoost achieving the best results. The current work demonstrates that new generated ML techniques can be reliably used to predict drag coefficient of non-spherical particles paving way towards generalization of ML approach.
{"title":"Data driven analysis of particulate systems for development of reliable model to determine drag coefficient of non-spherical particles","authors":"Tauseeq Hussain , Atta Ullah , Rehan Zubair Khalid , Farooq Ahmad , Fei Li , Asifullah Khan","doi":"10.1016/j.partic.2024.12.006","DOIUrl":"10.1016/j.partic.2024.12.006","url":null,"abstract":"<div><div>Non-spherical particles are extensively encountered in the process industry such as feedstock or catalysts e.g., energy, food, pharmaceuticals, and chemicals. The design of equipment used to process these particles is highly dependent upon the accurate and reliable modeling of hydrodynamics of particulate media involved. Drag coefficient of these particles is the most significant of all parameters. A universal model to predict the drag coefficient of such particles has not yet been developed due to the diversity and complexity of particle shapes and sizes. Taking this into consideration, we propose a unique approach to model the drag coefficient of non-spherical particles using machine learning (ML) to move towards generalization. A comprehensive database of approximately five thousand data points from reliable experiments and high-resolution simulations was compiled, covering a wide range of conditions. The drag coefficient was modeled as a function of Reynolds number, sphericity, Corey Shape Factor, aspect ratio, volume fraction, and angle of incidence. Three ML techniques—Artificial Neural Networks, Random Forest, and AdaBoost—were used to train the models. All models demonstrated strong generalization when tested on unseen data. However, AdaBoost outperformed the others with the lowest MAPE (20.1%) and MRD (0.069). Additional analysis on excluded data confirmed the robust predictive abilities and generalization of the proposed model. The models were also evaluated across three flow regimes—Stokes, transitional, and turbulent—to further assess their generalization. A comparative analysis with well-known empirical correlations, such as Haider and Levenspiel and Chien, showed that all ML models outperformed traditional approaches, with AdaBoost achieving the best results. The current work demonstrates that new generated ML techniques can be reliably used to predict drag coefficient of non-spherical particles paving way towards generalization of ML approach.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"97 ","pages":"Pages 219-235"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.partic.2024.12.001
Daniyar Kazidenov, Yerlan Amanbek
We numerically study the mechanisms and conditions for fracture initiation in weakly cohesive granular media induced by non-Newtonian polymer solutions. A coupled computational fluid dynamics–discrete element method (CFD-DEM) approach is utilized to model fluid flow in a porous medium. The flow behavior of polymer solutions and the drag force acting on particles are calculated using a power-law model. The adequacy of the numerical model is confirmed by comparing the results with a laboratory experiment. The numerical results are consistent with the experimental data presenting similar trends in dimensionless parameters that incorporate fluid flow rate, rheology, peak pressure, and confining stress. The results show that fluid flow rate, rheology, and solid material characteristics strongly influence fracture initiation behavior. Injection of a more viscous guar-based solution results in wider fractures induced by grain displacement, whereas a less viscous XG-based solution creates more linear fractures dominated by infiltration. The ratio of peak pressures between two fluids is higher in the rigid material than in the softer material. Finally, the dimensionless parameters 1/Π1 and τ2, which account for fluid and solid material properties accordingly, are effective indicators in determining fracture initiation induced by shear-thinning fluids. Our numerical results show that fracture initiation occurs above 1/Π1 = 0.06 and τ2 = 2 ⋅ 10−7.
{"title":"CFD-DEM modeling of fracture initiation with polymer injection in granular media","authors":"Daniyar Kazidenov, Yerlan Amanbek","doi":"10.1016/j.partic.2024.12.001","DOIUrl":"10.1016/j.partic.2024.12.001","url":null,"abstract":"<div><div>We numerically study the mechanisms and conditions for fracture initiation in weakly cohesive granular media induced by non-Newtonian polymer solutions. A coupled computational fluid dynamics–discrete element method (CFD-DEM) approach is utilized to model fluid flow in a porous medium. The flow behavior of polymer solutions and the drag force acting on particles are calculated using a power-law model. The adequacy of the numerical model is confirmed by comparing the results with a laboratory experiment. The numerical results are consistent with the experimental data presenting similar trends in dimensionless parameters that incorporate fluid flow rate, rheology, peak pressure, and confining stress. The results show that fluid flow rate, rheology, and solid material characteristics strongly influence fracture initiation behavior. Injection of a more viscous guar-based solution results in wider fractures induced by grain displacement, whereas a less viscous XG-based solution creates more linear fractures dominated by infiltration. The ratio of peak pressures between two fluids is higher in the rigid material than in the softer material. Finally, the dimensionless parameters 1/Π<sub>1</sub> and <em>τ</em><sub>2</sub>, which account for fluid and solid material properties accordingly, are effective indicators in determining fracture initiation induced by shear-thinning fluids. Our numerical results show that fracture initiation occurs above 1/Π<sub>1</sub> = 0.06 and <em>τ</em><sub>2</sub> = 2 ⋅ 10<sup>−7</sup>.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"97 ","pages":"Pages 58-68"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.partic.2024.12.008
Yulei Zhao , Mingyu Xiong , Yu Huang , Kin-fai Ho , Junji Cao , Long Cui
People spend the majority of their time indoors. Indoor airborne microorganisms, comprised of airborne particles containing fungi, bacteria, and virus present a significant concern in household environment due to their potential implications for indoor air quality and human health. This review synthesizes recent advancements in the fields of indoor air quality science, microbiology, and environmental engineering, providing insights into the sources, concentrations, transmission, influencing factors and control technology of indoor airborne microorganisms in residential environments. Factors such as occupant activities, pets, indoor temperature, humidity, and ventilation systems are critical in shaping the patterns and quantities of these microorganisms.
{"title":"A review of airborne microorganism transmission and control in household indoor air","authors":"Yulei Zhao , Mingyu Xiong , Yu Huang , Kin-fai Ho , Junji Cao , Long Cui","doi":"10.1016/j.partic.2024.12.008","DOIUrl":"10.1016/j.partic.2024.12.008","url":null,"abstract":"<div><div>People spend the majority of their time indoors. Indoor airborne microorganisms, comprised of airborne particles containing fungi, bacteria, and virus present a significant concern in household environment due to their potential implications for indoor air quality and human health. This review synthesizes recent advancements in the fields of indoor air quality science, microbiology, and environmental engineering, providing insights into the sources, concentrations, transmission, influencing factors and control technology of indoor airborne microorganisms in residential environments. Factors such as occupant activities, pets, indoor temperature, humidity, and ventilation systems are critical in shaping the patterns and quantities of these microorganisms.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"97 ","pages":"Pages 143-153"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.partic.2024.12.010
Jia Liu , Donghui Zhou , Cancan Zhu , Jinbao Han , Bo Yin
Under environment with various water contents, the variations in the mixing state and particle size of coated black carbon (BC) aerosols cause changes in optical and radiative effects. In this study, fractal models for thinly, partially, and thickly coated BC under six relative humidities (RHs = 0–95%) are constructed and optically simulated at 1064 and 532 nm. Differential scattering cross-sections are selected to retrieve the mixing state (Dp/Dc) of BC to investigate the possible retrieval errors caused by the nonspherical morphology when using the single-particle soot photometer (SP2). Furthermore, the radiative forcing of BC aerosols at different RHs are analyzed. Results showed that the retrieval errors (REs) of Dp/Dc are negative for coated particles with BC volume fraction smaller than 0.10, indicating that the mixing states of coated fractal BC are underestimated during the hygroscopic growth. The partially-coated BC has the best retrieval accuracy of the mixing state, followed by the closed-cell and coated-aggregate model, judging from averaged REs. Radiative forcing enhancements for partially-coated aerosols with different BC volume fractions exponentially increase to opposite values, resulting in a warming or cooling effect. This study helps understand the uncertainties in Dp/Dc of BC aerosols retrieved by SP2 and their radiative forcing at different RHs.
{"title":"Optical and radiative properties of coated black carbon during hygroscopic growth and retrieval errors of mixing state using single-particle soot photometer","authors":"Jia Liu , Donghui Zhou , Cancan Zhu , Jinbao Han , Bo Yin","doi":"10.1016/j.partic.2024.12.010","DOIUrl":"10.1016/j.partic.2024.12.010","url":null,"abstract":"<div><div>Under environment with various water contents, the variations in the mixing state and particle size of coated black carbon (BC) aerosols cause changes in optical and radiative effects. In this study, fractal models for thinly, partially, and thickly coated BC under six relative humidities (RHs = 0–95%) are constructed and optically simulated at 1064 and 532 nm. Differential scattering cross-sections are selected to retrieve the mixing state (<em>D</em><sub><em>p</em></sub>/<em>D</em><sub><em>c</em></sub>) of BC to investigate the possible retrieval errors caused by the nonspherical morphology when using the single-particle soot photometer (SP2). Furthermore, the radiative forcing of BC aerosols at different RHs are analyzed. Results showed that the retrieval errors (REs) of <em>D</em><sub><em>p</em></sub><em>/D</em><sub><em>c</em></sub> are negative for coated particles with BC volume fraction smaller than 0.10, indicating that the mixing states of coated fractal BC are underestimated during the hygroscopic growth. The partially-coated BC has the best retrieval accuracy of the mixing state, followed by the closed-cell and coated-aggregate model, judging from averaged REs. Radiative forcing enhancements for partially-coated aerosols with different BC volume fractions exponentially increase to opposite values, resulting in a warming or cooling effect. This study helps understand the uncertainties in <em>D</em><sub><em>p</em></sub>/<em>D</em><sub><em>c</em></sub> of BC aerosols retrieved by SP2 and their radiative forcing at different RHs.</div></div>","PeriodicalId":401,"journal":{"name":"Particuology","volume":"97 ","pages":"Pages 183-192"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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