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Micro-flow structure at regime transition from bubbling to turbulent fluidization in a fluidized bed

Particuology 2024年第6期89卷 117-130页

作者： Chaoyu Yan Yue Yuan Xiaoyang Wei jesse Zhu State Key Laboratory of Heavy Oil Processing Beijing Key Laboratory of Process Fluid Filtration and SeparationCollege of Mechanical and Transportation EngineeringChina University of PetroleumBeijing 102249China China Beacons Institute The University of NottinghamNingbo315100China Department of Chemical and Biochemical Engineering University of Western OntarioLondonOntarioN6A 5B9Canada

Gas-solid fluidized beds have found extensive utilization in frontline manufacturing,in particular as low-velocity beds.The fluidization status,the bubbling or turbulent flow regime and the transition in between,determine the system performance in practical applications.Though the convoluted hydrodynamics are quantitively evaluated through numerous data-processing methodologies,none of them alone can reflect all the critical information to identify the transition from the bubbling to the turbulent regime.Accordingly,this study was to exploit a coupling data processing methodology,in the combination of standard deviation,power spectrum density,probability density function,wavelet transform,and wavelet multiresolution method,to jointly explain the micro-flow structure at the regime transition from bubbling to turbulent fluidization.The transient differential pressure fluctuation was measured for the evaluation in a fluidized bed(0.267 m i.d.×2.5 m height)with FCC catalysts(d_(p)=65μm,ρ_(p)=1780kg/m^(3))at different superficial gas velocities(0.02–1.4 m/s).The results show that the onset of turbulent fluidization starts earlier in the top section of the bed than in the bottom section.The wavelet decomposition displays that the fluctuation of differential pressure mainly concentrates on the sub-signals with an intermediate frequency band.These sub-signals could be synthesized into three types of scales(micro-scale,meso-scale,and macro-scale),representing the multi-scale hydrodynamics in the fluidized bed.The micro-scale signal has the characteristic information of bubbling fluidization,and the characteristic information of turbulent fluidization is mainly represented by the meso-scale signal.This work provides a systematic comprehension of fluidization status assessment and serves as an impetus for more coupling analysis in this sector.

关键词： Flow regime transition Bubbling fluidization Turbulent fluidization Micro-flow structure Differential pressure fluctuation

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Coverage and determinants of infant postnatal care in Nigeria: A population-based cross-sectional study

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儿科学研究(英文) 2024年第1期8卷 27-36页

作者： Egbewale Bolaji Emmanuel Oyedeji Olusola Bump jesse Sudfeld Christopher Robert Department of Global Health and Population Takemi Program in International Health Harvard T. H. Chan School of Public Health Boston Massachusetts USA Department of Community Medicine College of Health Sciences Ladoke Akintola University of Technology Ogbomoso Nigeria Department of Pediatrics and Child Health College of Health Sciences Ladoke Akintola University of Technology Ogbomoso Nigeria

Importance: In 2019, Nigeria had the largest number of under-5 child deaths globally and many of these deaths occurred within the first week of life. The World Health Organization recommends infant postnatal care (PNC) attendance to support newborn survival; however, utilization of PNC is known to be low in many contexts.Objective: This study examined coverage and individual-level determinants of infant PNC attendance in Nigeria.Methods: Nigeria Demographic Health Survey (NDHS) 2018 data were used to evaluate infant PNC coverage and determinants. Infant PNC was defined as receipt of care within 2 days of birth. Children delivered up to 2 years before the 2018 NDHS were included. We examined predictors of infant PNC with modified Poisson regression models to estimate relative risks (RRs).Results: The national coverage of infant PNC was 37.3% (95% confidence interval [CI]: 35.8%–38.7%). Significant heterogeneity in PNC attendance existed at state and regional levels. Facility delivery was strongly associated with the uptake of PNC (RR: 6.07; 95% CI: 5.60–6.58). Greater maternal education, maternal employment, urban residence, female head of household, and greater wealth were also associated with an increased likelihood of PNC visits.Interpretation: The uptake of infant PNC is low and interventions are urgently needed to promote equity in access and increase demand for PNC in Nigeria.

关键词： Infant postnatal care Epidemiology Coverage Determinants Nigeria

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A Machine Learning-Based Web Application for Heart Disease Prediction

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Intelligent Control and Automation 2024年第1期15卷 9-27页

作者： jesse Gabriel Independent Researcher Port Moresby Papua New Guinea

This work leveraged predictive modeling techniques in machine learning (ML) to predict heart disease using a dataset sourced from the Center for Disease Control and Prevention in the US. The dataset was preprocessed and used to train five machine learning models: random forest, support vector machine, logistic regression, extreme gradient boosting and light gradient boosting. The goal was to use the best performing model to develop a web application capable of reliably predicting heart disease based on user-provided data. The extreme gradient boosting classifier provided the most reliable results with precision, recall and F1-score of 97%, 72%, and 83% respectively for Class 0 (no heart disease) and 21% (precision), 81% (recall) and 34% (F1-score) for Class 1 (heart disease). The model was further deployed as a web application.

关键词： Heart Disease US Center for Disease Control and Prevention Machine Learn-ing Imbalanced Data Web Application

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光电极表面态的静态结构与时间分辨动力学和频光谱研究

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Chinese Journal of Chemical Physics 2024年第2期37卷 376-397,I0105页

作者：张彤 jesse B.Brown Haley Fisher Mallory Liebes 皇甫至超钱余亲饶毅美国犹他州立大学化学与生物化学系犹他州洛根84322

在光催化或光电催化反应过程中,光电极的表面态扮演着重要的角色,影响着电荷的产生、分离和利用过程,从而很大程度上决定了光电极的催化性能,通常用于研究光电极表面态以改进其性能的方法是间接的、非表面特异性的以及需要超高真空条件... 详细信息

在光催化或光电催化反应过程中,光电极的表面态扮演着重要的角色,影响着电荷的产生、分离和利用过程,从而很大程度上决定了光电极的催化性能,通常用于研究光电极表面态以改进其性能的方法是间接的、非表面特异性的以及需要超高真空条件下进行的方法,无法获得真实条件下的表面态信息。电子和频光谱和电子二次谐波等非线性光学方法具有表面特异性,可以在各种条件下实现表界面系统的原位研究.本研究介绍了表面态的重要性及其与催化性能的密切关系,概述研究半导体表面态、电场和载流子动力学的方法,并重点介绍了界面特异性光谱方法在该领域的最新贡献.包括通过相位信息提取带电表面态的宽带外插法电子二次谐波技术,提供表面态动力学信息的时间分辨电子和频光谱技术和探索表面态耦合的二维电子和频光谱技术,这些非线性光学方法的进一步发展将实现对光电极表面态和界面电子特性的多角度原位表征,提供对表面态及表面电荷转移过程更深层次的理解,以启发未来光催化和光电催化材料的研究和改进.

关键词：表面态电子和频光谱光催化光电催化

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Circulating microRNA expression and nonalcoholic fatty liver disease in adolescents with severe obesity

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World Journal of Gastroenterology 2024年第4期30卷 332-345页

作者： Yi-Jie Li Brittney O Baumert Nikos Stratakis jesse A Goodrich Hao-Tian Wu Jing-Xuan He Yin-Qi Zhao Max T Aung Hong-Xu Wang Sandrah P Eckel Douglas I Walker Damaskini Valvi Michele A La Merrill Justin R Ryder Thomas H Inge Todd Jenkins Stephanie Sisley Rohit Kohli Stavra A Xanthakos Andrea A Baccarelli Rob McConnell David V Conti Lida Chatzi Department of Population and Public Health Sciences Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCA 90032United States Barcelona Institute of Global Health Barcelona Institute of Global HealthBarcelona 08036Spain Department of Environmental Health Sciences Mailman School of Public HealthColumbia UniversityNew YorkNY 10032United States Gangarosa Department of Environmental Health Rollins School of Public HealthEmory UniversityAtlantaGA 30329United States Department of Environmental Medicine and Public Health Icahn School of Medicine at Mount SinaiNew YorkNY 10029United States Department of Environmental Toxicology University of CaliforniaDavisCA 95616United States Department of Surgery Lurie Children’s Hospital of ChicagoChicagoIL 60611United States Northwestern University Feinberg School of Medicine Northwestern UniversityChicagoIL 60611United States Division of Biostatistics and Epidemiology Cincinnati Children's Hospital Medical CenterCincinnatiOH 45229United States Department of Pediatrics University of Cincinnati College of MedicineCincinnatiOH 45229United States Department of Pediatrics Children’s Nutrition Research Center USDA/ARSBaylor College of MedicineHoustonTX 77030United States Department of Gastroenterology Children’s Hospital Los AngelesLos AngelesCA 90027United States Division of Gastroenterology Hepatology and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOH 45229United States

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases in children and adolescents.NAFLD ranges in severity from isolated hepatic steatosis to nonalcoholic steatohepatitis(NASH),wherein hepatocellular inflammation and/or fibrosis coexist with steatosis.Circulating microRNA(miRNA)levels have been suggested to be altered in NAFLD,but the extent to which miRNA are related to NAFLD features remains unknown.This analysis tested the hypothesis that plasma miRNAs are significantly associated with histological features of NAFLD in adolescents.AIM To investigate the relationship between plasma miRNA expression and NAFLD features among adolescents with NAFLD.METHODS This study included 81 adolescents diagnosed with NAFLD and 54 adolescents without NAFLD from the Teen-Longitudinal Assessment of Bariatric Surgery study.Intra-operative core liver biopsies were collected from participants and used to characterize histological features of NAFLD.Plasma samples were collected during surgery for miRNA profiling.A total of 843 plasma miRNAs were profiled using the HTG EdgeSeq platform.We examined associations of plasma miRNAs and NAFLD features using logistic regression after adjusting for age,sex,race,and other key covariates.Ingenuity Pathways Analysis was used to identify biological functions of miRNAs that were associated with multiple histological features of NAFLD.RESULTS We identified 16 upregulated plasma miRNAs,including miR-193a-5p and miR-193b-5p,and 22 downregulated plasma miRNAs,including miR-1282 and miR-6734-5p,in adolescents with NAFLD.Moreover,52,16,15,and 9 plasma miRNAs were associated with NASH,fibrosis,ballooning degeneration,and lobular inflammation,respectively.Collectively,16 miRNAs were associated with two or more histological features of NAFLD.Among those miRNAs,miR-411-5p was downregulated in NASH,ballooning,and fibrosis,while miR-122-5p,miR-1343-5p,miR-193a-5p,miR-193b-5p,and miR-7845-5p were consistently and positively associated with all histological features

关键词： MicroRNA Nonalcoholic fatty liver disease Non-alcoholic steatohepatitis Liver fibrosis Lobular inflammation Ballooning degeneration

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Experimental study on reactor performance of gas-solids low-velocity fluidized beds

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Particuology 2022年第7期20卷 21-28页

作者： Jiangshan Liu jesse Zhu Particle Technology Research Centre Department of Chemical and Biochemical EngineeringThe University of Western OntarioLondonOntarioN6A 3K7Canada

Reactor performance of bubbling fluidized bed(BFB)and turbulent fluidized bed(TFB)was carefully examined and systematically compared using catalytic ozone decomposition as a model reaction,based on a complete mapping of local flow structures and spatial distributions of ozone conversion and solids holdup.TFB clearly has a higher conversion and shows better reactor performance than BFB as a result of the vigorously turbulent flow and the relatively homogeneous gas–solids mixing in TEB.Besides,the intensive interaction between gas and solids in TFB leads to greater gas–solids contact efficiency of TFB over that of BFB.Due to gas bypassing and backmixing caused by bubbling behaviours and two-phase structure,BFB deviates significantly from a plug flow reactor and sometimes from a continuously stirred tank reactor.The flow structures essentially dictate the reactor performance in the low-velocity fluidized beds.

关键词： Bubbling fluidized bed Turbulent fluidized bed Conversion distribution Flow structure Reactor performance Gas–solids contact efficiency

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Intelligent Intercommunicating Multiscale Engineering: The Engineering of the Future

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Engineering 2023年第11期30卷 13-19页

作者： Yue Yuan jesse Zhu China Beacons Institute The University of NottinghamNingbo 315100China Particle Technology Research Center Department of Chemical and Biochemical EngineeringThe University of Western OntarioLondonON N6A 5B9Canada

1.Introduction Despite being widely known and investigated as a computer science discipline,artificial intelligence(AI)has attracted incomparable interest from researchers in diversified areas[1].In 1950,Alan Turing raised the classic question that has inspired numerous researchers to date:“Can machines think?”[2].The ultimate benchmark of AI was set by Turing’s revised“imitation game.”

关键词： computer artificial Turing

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Numerical investigations on gas-solid flow in circulating fluidized bed risers using a new cluster-based drag model

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Particuology 2022年第4期20卷 9-23页

作者： Zeneng Sun Chao Zhang jesse Zhu Department of Chemical and Biochemical Engineering.The University of Western Ontario LondonOntarioN6A 3K7Canada Department of Mechanical and Materials Engineering The University of Western OntarioLondonOntarioN6A 3K7Canada

A cluster-based drag model is proposed for the gas-solid circulating fluidized bed(CFB)riser by including the cluster information collected from image processing and wavelet analysis into the calculation of system drag.The performance of the proposed drag model is compared with some commonly used drag models.A good agreement with the experimental data is achieved by the proposed cluster-based drag model.Error analysis of the proposed cluster-based drag model based on the local distributions of solids holdup and particle velocity is conducted.The clustering phenomenon in the low-density and high-density CFB risers and the effect of the cluster size on the simulation accuracy are also numerically studied by the proposed drag model.

关键词： Drag model Clustering effect Gas-solid flow structures Circulating fluidized bed

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Improving flow and fluidization quality of fine and ultrafine particles via nanoparticle modulation

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Nano Research 2023年第10期16卷 12013-12025页

作者： Jiaying Wang Yuanyuan Shao jesse Zhu Department of Chemical and Biochemical Engineering The University of Western OntarioLondonOntario N6A 3K7Canada School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Beacons of Excellence Research and Innovation Institute University of NottinghamNingbo 315100China

Fine and ultrafine particles possess great potential for industrial applications ascribed from their huge specific surface area and ability to provide good gas–solid contact.However,these powders are inherently cohesive,making it challenging to achieve smooth flow and fluidization.This challenge can be well-resolved by nanoparticle modulation(nano-modulation),where a small amount of nanoparticles is uniformly mixed with the cohesive fine/ultrafine powders.Through nano-modulation,the fluidization system of cohesive powders exhibits distinguishable minimum fluidization velocity,enlarged bed expansion ratio(particularly the dense phase expansion),and scarcer,smaller,and slower moving bubbles,indicating improved flow and fluidization quality.The purpose of the current work is to systematically summarize the state-of-the-art progress in the fluidization and utilization of fine and ultrafine particles via the nanoparticle modulation method.Accordingly,a broader audience can be enlightened regarding this promising fine/ultrafine particle fluidization technology,so as to provoke their attention and encourage interdisciplinary integration and industry-academia collaborative research.

关键词： fine particle ultrafine particle cohesive powder flowability fluidization nanoparticle modulation

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Recent Developments in Hydrodynamic Cavitation Reactors:Cavitation Mechanism,Reactor Design,and Applications

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Engineering 2022年第12期19卷 180-198页

作者： Haoxuan Zheng Ying Zheng jesse Zhu Department of Chemical and Biochemical Engineering University of Western OntarioLondonON N6A 3K7Canada

Hydrodynamic cavitation is considered to be a promising technology for process intensification,due to its high energy efficiency,cost-effective operation,ability to induce chemical reactions,and scale-up possibilities.In the past decade,advancements have been made in the fundamental understanding of hydrodynamic cavitation and its main variables,which provide a basis for applications of hydrodynamic cavitation in radical-induced chemical reaction processes.Here,we provide an extensive review of these research efforts,including the fundamentals of hydrodynamic cavitation,the design of cavitation reactors,cavitation-induced reaction enhancement,and relevant industrial applications.Two types of hydrodynamic cavitation reactors—namely,stationary and rotational—are compared.The design parameters of a hydrodynamic cavitation reactor and reactor performance at the laboratory and pilot scales are discussed,and recommendations are made regarding optimal operation and geometric conditions.The commercial cavitation reactors that are currently on the market are reviewed here for the first time.The unique features of hydrodynamic cavitation have been widely applied to various chemical reactions,such as oxidization reactions and wastewater treatment,and to physical processes,such as emulsion generation and component extraction.The roles of radicals and gas bubble implosion are also thoroughly discussed.

关键词： Hydrodynamic cavitation Cavitation nuclei Hydroxyl radicals Stationary/rotational hydrodynamic cavitation reactor Reaction enhancement Cavitation application

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