Experimental Investigation of the Hydrodynamics in a Liquid-Solid Riser

Liquid-Solid Fluid Dynamics Has Been Investigated in a 6-In. (0.15 M) Cold-Flow Circulating Fluidized Bed Riser using Non-Invasive Flow Monitoring Methods. Gamma-Ray Computed Tomography (CT) Was Used to Measure the Time-Averaged Cross-Sectional Solids Volume Fraction Distributions at Several Elevations. the Time-Averaged Mean and Fluctuating Solids Velocity Fields Were Quantified using the Computer-Automated Radioactive Particle Tracking (CARPT) Technique. the Experimental Equipment, Protocol of Implementation, and Data Analysis Have Been Discussed Briefly, with Particular Emphasis on the Specific Features in the Use of These Techniques for Studying High-Density Turbulent Flows as in a Liquid-Solid Riser. the Experimental Study Examines Nine Operating Conditions, that Is, Three Liquid Superficial Velocities and Three Solids Flow Rates. the Solids Holdup Profile is Found to Be Relatively Uniform Across the Cross Section of the Riser, with Marginal Segregation Near the Walls. the Time-Averaged Solids Velocity Profiles Are Found to Have a Negative Component at the Walls, Indicating Significant Solids Backmixing. Detailed Characterization of the Solids Velocity Fields in Terms of RMS Velocities, Kinetic Energies, Hurst Exponents, Residence Time Distributions, Trajectory Length Distributions, Dispersion Coefficients, and So Forth Are Presented. Comparative and Symbiotic Analyses of the Results Were Used to Develop a Coherent Picture of the Solids Flow Field. in Addition, the Work Also Serves to Demonstrate the Power and Versatility of These Flow-Imaging Techniques in Studying Highly Turbulent and Opaque Multiphase Systems. © 2005 American Institute of Chemical Engineers

A Lagrangian Description of Flows in Stirred Tanks Via Computer-Automated Radioactive Particle Tracking (CARPT)

In This Study, Computer-Automated Radioactive Particle Tracking (CARPT) is Implemented for the First Time in the Characterization of Flows in Stirred Tanks. Both the Experimental Set-Up Are Discussed. the CARPT Technique is Seen to Capture Qualitatively Most of the Important Flow Phenomena Observed in Stirred Tank Flows, Like the Two Recirculating Loops above and Below the Impeller and the Dead Zones at the Bottom of the Tank. the CARPT Data is Also Used to Extract \u27\u27Sojourn\u27\u27 Time Distributions in Different Zones of the Reactor. These Distributions Are Used to Partially Quantify the Observed Dead and Active Zones in the Tank. © 2001 Elsevier Science Ltd. All Rights Reserved

IMPACT OF TYPE 2 DIABETES ON THE DEVELOPMENT OF PERIODONTAL DISEASE IN THE MOUSE

Oral Communication presented at the ";;Forum des Jeunes Chercheurs";;, Brest (France) 2011

Inferring Liquid Chaotic Dynamics in Bubble Columns

Experiments Carried Out to Study the Liquid Displacements in Bubble Columns Via the Computer Automated Radioactive Particle Tracking Technique Are Analyzed by Means of Lagrangian and Qualitative Dynamics Tools. the Lagrangian Approach Yields the Detailed Motion Sequences of the Tracer as Entrained by the Fast Ascending Bubbles or by the Liquid Flow Alongside the Column Walls. the Qualitative Dynamics Tools, on the Other Hand, Provide Prima Facie Corroboration of Chaos in Liquid Motion based on an Analysis of the Volume-Averaged Kolmogorov Entropy and the Mutual Information Function. Other Features of the Chaotic Motion, the Reconstructed Attractors and the Radial and Axial Distributions of Lyapunov Exponents, Are Noted. Variations in the Liquid Hydrodynamics Due to Changes in Column Diameter and Operating Pressure Are Inspected. by Increasing Pressure the Attractor\u27s Correlation Dimension and the Information Loss Rate Decrease, Whereas the Liquid Flow Path is Dramatically Affected. © 2001 Published by Elsevier Science Ltd

Comparative Hydrodynamics Study in a Bubble Column using Computer-Automated Radioactive Particle Tracking (CARPT)/computed Tomography (CT) and Particle Image Velocimetry (PIV)

The Hydrodynamics of a 10-Cm-Diameter Cylindrical Bubble Column at the Superficial Gas Velocity of 2, 4, and 8 Cm/s Are Investigated by Computer-Automated Radioactive Particle Tracking (CARPT), Particle Image Velocimetry (PIV), and Computed Tomography (CT). These Experimental Techniques Are Capable of Providing the Knowledge of Velocity and Holdup Fields in a Bubble Column System, Which Are Essential as the Experimental Benchmark for Modeling of Such Systems. the Flow Field of Liquid Phase, as Well as the Reynolds Stresses, Obtained by CARPT and PIV in an Air-Water System Are Compared in Detail. the Results Indicate that CARPT and PIV Complement Each Other Well. Further, the Profile of Gas Holdup Obtained by Gamma Ray based on CT Compares Favorably to the Independently Determined Holdup

Gas Holdup in a Trayed Cold-Flow Bubble Column

An Experimental Study Was Performed to Investigate the Effect of Sieve Trays on the Time-Averaged Gas Holdup Profiles and the overall Gas Holdup in a Cold-Flow Bubble Column that Was Scaled-Down from a Commercial Unit. Γ-Ray Computed Tomography (CT) Was Used to Scan the Column at Several Axial Locations in the Presence and Absence of Trays from Which the Local Variation of the Gas Holdup Was Extracted. the overall Gas Holdup Was Also Determined using the Same Configuration by Comparing the Expanded and Static Liquid Heights. Air and Water Were Used as the Gas-Liquid System. the Superficial Gas and Liquid Velocities Were Selected to Span the Range of the Commercial System using Gas Spargers Having Multiple Lateral Distributors that Were Also Scaled-Down from the Commercial Design. to Investigate the Impact of Sparger Hole Density on the Local and overall Gas Holdup, Two Difference Sparger Designs Were Used in Which the Hole Density Per Lateral Was Varied. the Gas Hole Velocity Was Maintained Constant at Ca. 245 M/s, Which Approached that Used in the Commercial Reactor. It is Shown that the Local Gas Holdup Determined by CT is Generally Higher in the Tray Down Comer Region and Exhibits an Asymmetric Pattern When Trays Are Present. the Use of Increased Sparger Hole Density at a Constant Gas Superficial Velocity Leads to Steeper Gradient in the Gas Holdup Near the Column Centerline and a Higher overall Gas Holdup. These Findings Suggest that the Performance of Bubble Column Reactors for Various Applications is Sensitive to Both Sparger and Tray Design. © 2001 Elsevier Science Ltd. All Rights Reserved

A comprehensive fracture prevention strategy in older adults : The European union geriatric medicine society (EUGMS) statement

Published also in Aging Clinical and Experimental Research, Vol.28, No.4, WOS: 000379034800030Prevention of fragility fractures in older people has become a public health priority, although the most appropriate and cost-effective strategy remains unclear. In the present statement, the Interest group on falls and fracture prevention of the European union geriatric medicine society (EUGMS), in collaboration with the International association of gerontology and geriatrics for the European region (IAGG-ER), the European union of medical specialists (EUMS), the Fragility fracture network (FFN), the International osteoporosis foundation (IOF) - European society for clinical and economic aspects of osteoporosis and osteoarthritis (ECCEO), outlines its views on the main points in the current debate in relation to the primary and secondary prevention of falls, the diagnosis and treatment of bone fragility, and the place of combined falls and fracture liaison services for fracture prevention in older people. (C) 2016 Published by Elsevier Masson SAS.Peer reviewe

A comprehensive fracture prevention strategy in older adults: The European union geriatric medicine society (EUGMS) statement

Prevention of fragility fractures in older people has become a public health priority, although the most appropriate and cost-effective strategy remains unclear. In the present statement, the Interest group on falls and fracture prevention of the European union geriatric medicine society (EUGMS), in collaboration with the International association of gerontology and geriatrics for the European region (IAGG-ER), the European union of medical specialists (EUMS), the Fragility fracture network (FFN), the International osteoporosis foundation (IOF) – European society for clinical and economic aspects of osteoporosis and osteoarthritis (ECCEO), outlines its views on the main points in the current debate in relation to the primary and secondary prevention of falls, the diagnosis and treatment of bone fragility, and the place of combined falls and fracture liaison services for fracture prevention in older people