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Full-Text Articles in Engineering
Fabrication Of Cao-Nao-Sio2/Tio2 Scaffolds For Surgical Applications, A. W. Wren, A. Coughlan, K. E. Smale, S. T. Misture, B. P. Mahon, O. M. Clarkin, Mark R. Towler
Fabrication Of Cao-Nao-Sio2/Tio2 Scaffolds For Surgical Applications, A. W. Wren, A. Coughlan, K. E. Smale, S. T. Misture, B. P. Mahon, O. M. Clarkin, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
A series of titanium (Ti) based glasses were formulated (0.62 SiO2-0.14 Na2O-0.24 CaO, with 0.05 mol% TiO2 substitutions for SiO2) to develop glass/ceramic scaffolds for bone augmentation. Glasses were initially characterised using X-ray diffraction (XRD) and particle size analysis, where the starting materials were amorphous with 4.5 μm particles. Hot stage microscopy and high temperature XRD were used to determine the sintering temperature (̃700 °C) and any crystalline phases present in this region (Na2Ca3Si6O16, combeite and quartz). Hardness testing revealed that the Ti-free control (ScC- …
Developing Novel Prognostic Biomarkers For Multivariate Fracture Risk Prediction Algorithms, Ernest K. Poku, Mark R. Towler, Niamh M. Cummins, Jeff D. Newman
Developing Novel Prognostic Biomarkers For Multivariate Fracture Risk Prediction Algorithms, Ernest K. Poku, Mark R. Towler, Niamh M. Cummins, Jeff D. Newman
Chemical and Biochemical Engineering Faculty Research & Creative Works
Multivariate prediction algorithms such as FRAX® and QFracture Scores provide an opportunity for new prognostic biomarkers to be developed and incorporated, potentially leading to better fracture prediction. As more research is conducted into these novel biomarkers, a number of factors need to be considered for their successful development for inclusion in these algorithms. In this review, we describe two well-known multivariate prediction algorithms for osteoporosis fracture risk applicable to the UK population, FRAX and QFracture Scores, and comment on the current prognostic tools available for fracture risk; dual X-ray assessment, quantitative ultrasonography, and genomic/biochemical markers. We also highlight the factors …
Gallium Containing Glass Polyalkenoate Anti-Cancerous Bone Cements: Glass Characterization And Physical Properties, A. W. Wren, A. Coughlan, L. Placek, Mark R. Towler
Gallium Containing Glass Polyalkenoate Anti-Cancerous Bone Cements: Glass Characterization And Physical Properties, A. W. Wren, A. Coughlan, L. Placek, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
A gallium (Ga) glass series (0.48SiO2-0.40ZnO-0.12CaO, with 0.08 mol% substitution for ZnO) was developed to formulate a Ga-containing Glass Polyalkenoate Cement (GPC) series. Network connectivity (NC) and X-ray Photoelectron Spectroscopy (XPS) was employed to investigate the role of Ga3+ in the glass, where it is assumed to act as a network modifier. Ga-GPC series was formulated with E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60 wt% additions. E11 working times (Tw) ranged from 68 to 96 s (Lcon.) and 106 s for the Ga-GPCs (LGa-1 and LGa-2). Setting times (Ts) …
Experimental Composite Guidance Conduits For Peripheral Nerve Repair: An Evaluation Of Ion Release, X. F. Zhang, A. Coughlan, H. O'Shea, Mark R. Towler, S. Kehoe, D. Boyd
Experimental Composite Guidance Conduits For Peripheral Nerve Repair: An Evaluation Of Ion Release, X. F. Zhang, A. Coughlan, H. O'Shea, Mark R. Towler, S. Kehoe, D. Boyd
Chemical and Biochemical Engineering Faculty Research & Creative Works
Poly (lactide-co-glycolide) (PLGA) - Pluronic F127 - glass composites have demonstrated excellent potential, from the perspective of controlled mechanical properties and cytocompatibility, for peripheral nerve regeneration. In addition to controlling the mechanical properties and cytotoxicity for such composite devices, the glass component may mediate specific responses upon implantation via degradation in the physiological environment and release of constituent elements. However, research focused on quantifying the release levels of such therapeutic ions from these experimental medical devices has been limited. To redress the balance, this paper explores the ion release profiles for Si4+, Ca2+, Na+, …
The Structural Characterization Of Ga 2o 3-Na 2o-Cao-Zno-Sio 2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, M. M. Hall, Mark R. Towler
The Structural Characterization Of Ga 2o 3-Na 2o-Cao-Zno-Sio 2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, M. M. Hall, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
The characterization of bioactive glasses in which zinc (Zn) has been incrementally replaced by gallium (Ga). © 2012 IEEE.
Silver Coated Bioactive Glass Particles For Wound Healing Applications, P. Hassanzadeh, A. W. Wren, Mark R. Towler
Silver Coated Bioactive Glass Particles For Wound Healing Applications, P. Hassanzadeh, A. W. Wren, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
Hench and colleagues discovered that bone could bond chemically to certain glass compositions in 1969 [1]. This group of glasses is known as bioactive glasses [1]. Some special compositions of bioactive glasses will bond to soft tissues as well as bone [1]. One of the important characteristics of bioactive glasses is their ability to release beneficial ions such as Ca2+, Na+, Zn2+, Sr2+, and PO 43- in the body, which promote self-healing [2]. Bioactive glasses generally contain much less glass former (e.g., SiO2, B2O3 etc.) than conventional …
Increasing The Quantity Of Silver In Zinc-Based Glass Polyalkenoate Cement: Is There An Improvement In Antibacterial Efficacy?, A. Coughlan, S. M. Breed, C. Ashraf, J. A. Cardinale, M. M. Hall, Mark R. Towler
Increasing The Quantity Of Silver In Zinc-Based Glass Polyalkenoate Cement: Is There An Improvement In Antibacterial Efficacy?, A. Coughlan, S. M. Breed, C. Ashraf, J. A. Cardinale, M. M. Hall, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
Bone cements should have the ability to chemically bond to both bone and surgical metals, exhibit no chemical or thermal necrosis, and have no significant shrinkage or exotherm upon setting. Taking these properties into consideration, glass polyalkenoate cements (GPCs) have potential as bone cements. GPCs are formed by the reaction between an ion-leachable glass and an aqueous solution of polyacrylic acid (PAA) [1] and have proven antibacterial and cariostatic properties [2], which are related to their ability to release beneficial amounts of ions over time [3, 4]. The GPCs can be formulated to release ions that can have a therapeutic …
Gallium Containing Glass Polyalkenoate Bone Cements: Glass Characterization And Physical Properties, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler
Gallium Containing Glass Polyalkenoate Bone Cements: Glass Characterization And Physical Properties, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
Gallium (Ga) glasses were developed to formulate a Glass Polyalkenoate Cement (GPC) series with both E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60wt% additions. Working times (T w), setting times (T s), compression (σ c), and biaxial flexural (σ f) strength testing were evaluated to determine the GPCs potential use in orthopedics. © 2012 IEEE.
Silver Coated Bioactive Glass Particles For Wound Healing Applications, A. W. Wren, A. Coughlan, P. Hassanzadeh, Mark R. Towler
Silver Coated Bioactive Glass Particles For Wound Healing Applications, A. W. Wren, A. Coughlan, P. Hassanzadeh, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
Bioactive glass particles (0.42SiO2-0.15CaO-0.23Na 2O-0.20ZnO) of varying size (<90 >μm and 425-850 μm) were synthesized and coated with silver (Ag) to produce Ag coated particles (PAg). These were compared against the uncoated analogous particles (Pcon.). Surface area analysis determined that Ag coating of the glass particles resulted in increased the surface area from 2.90 to 9.12 m2/g (90 μm) and 1.09-7.71 m2/g (425-850 μm). Scanning electron microscopy determined that the Ag coating remained at the surface and there was little diffusion through the bulk. Antibacterial (Escherichia coli - 13 mm and Staphylococcus epidermidis …
On The Measurement Of Gas Holdup Distribution Near The Region Of Impeller In A Gas-Liquid Stirred Rushton Tank By Means Of Γ-Ct, Li Na Kong, Wei Li, Lu Chang Han, Yue Jin Liu, He An Luo, Muthanna H. Al Dahhan, Milorad P. Dudukovic
On The Measurement Of Gas Holdup Distribution Near The Region Of Impeller In A Gas-Liquid Stirred Rushton Tank By Means Of Γ-Ct, Li Na Kong, Wei Li, Lu Chang Han, Yue Jin Liu, He An Luo, Muthanna H. Al Dahhan, Milorad P. Dudukovic
Chemical and Biochemical Engineering Faculty Research & Creative Works
Three Flow Patterns of Flooding, Loading and Complete Recirculation in a Gas-Liquid Stirred Rushton Tank Were Identified based on Experimental Observation. the Gas-Liquid System Was Composed of Air and Water. under Different Operating Conditions of Gas Flow Rate and Impeller Rotating Speed, the Distribution of Gas Holdup Near the Region of Impeller Was Measured using a Γ-CT Scan Method. Both Quantitative Digital Distribution Curves of Gas Holdup and their Qualitative Color CT Images Were Obtained. at the Region of Impeller, There Was a Convex Characteristic Peak of Gas Holdup Distribution Both in Radial and in Axial Directions, and with the …
Airlift Column Photobioreactors For Porphyridium Sp. Culturing: Part I. Effects Of Hydrodynamics And Reactor Geometry, Hu Ping Luo, Muthanna H. Al-Dahhan
Airlift Column Photobioreactors For Porphyridium Sp. Culturing: Part I. Effects Of Hydrodynamics And Reactor Geometry, Hu Ping Luo, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
Photosynthetic Microorganisms Have Been Attracting World Attention for their Great Potential as Renewable Energy Sources in Recent Years. Cost Effective Production in Large Scale, However, remains a Major Challenge to overcome. It is Known to the Field that Turbulence Could Help Improving the Performance of Photobioreactors Due to the So-Called Flashing Light Effects. Better Understanding of the Multiphase Fluid Dynamics and the Irradiance Distribution Inside the Reactor that Cause the Flashing Light Effects, as Well as Quantifying their Impacts on the Reactor Performance, Thus, Are Crucial for Successful Design and Scale-Up of Photobioreactors. in This Study, a Species of Red …
Impact Of Internals On The Heat-Transfer Coefficient In A Bubble Column, Rahman S. Abdulmohsin, Muthanna H. Al-Dahhan
Impact Of Internals On The Heat-Transfer Coefficient In A Bubble Column, Rahman S. Abdulmohsin, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
The Effect of Heat Exchanging Internals on the Heat-Transfer Coefficient Has Been Investigated in a 0.19 M Diameter Bubble Column. an Air-Water System Was Used with Superficial Gas Velocities Varying from 3 to 20 Cm/s, Which Cover Both the Bubbly and Churn-Turbulent Flow Regimes. Internals Occluding 0% (Empty Column), 5% (Simulating Methanol Synthesis), and 22% (Simulating Fischer-Tropsch Synthesis) of the Column Cross-Sectional Area Were Implemented. a Fast Response Heat-Transfer Probe Was Utilized to Measure the Radial Profile of the Heat-Transfer Coefficient in the Fully Developed Flow Region. the Results Indicate that the Presence of a High Percentage of Internals Causes …
Influence Of Solid-Phase Wall Boundary Condition On Cfd Simulation Of Spouted Beds, Xingying Lan, Chunming Xu, Jinsen Gao, Muthanna H. Al-Dahhan
Influence Of Solid-Phase Wall Boundary Condition On Cfd Simulation Of Spouted Beds, Xingying Lan, Chunming Xu, Jinsen Gao, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
The Influence of Solid-Phase Wall Boundary Condition in Terms of Specularity Coefficient and Particle-Wall Restitution Coefficient on the Flow Behavior of Spouted Beds Was Investigated using Two-Fluid Model Approach in the Computational Fluid Dynamics Software FLUENT 6.3. Parametric Studies of Specularity Coefficient and Particle-Wall Restitution Coefficient Were Performed to Evaluate their Effects on the Flow Hydrodynamics in Terms of Fountain Height, Spout Diameter, Pressure Drop, Local Voidage and Particles Velocity. the Numerical Predictions Were Compared with Available Experimental Data in the Literatures to Obtain the Suitable Values of Specularity Coefficient and Particle-Wall Restitution Coefficient for Spouted Beds. the Simulated Results …
Heat Transfer Coefficients In Mimicked Fischer-Tropsch Slurry Bubble Columns, Chengtian Wu, Muthanna H. Al-Dahhan
Heat Transfer Coefficients In Mimicked Fischer-Tropsch Slurry Bubble Columns, Chengtian Wu, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
To Provide More Support for Fischer-Tropsch (FT) Slurry Bubble Column Reactor Design, Scale-Up, and Performance, the Effects of Operating Conditions on the Heat Transfer Coefficients Were Investigated in a Mimicked FT Cold Flow System (Compressed Air:C 9-C 11:FT Catalyst Carrier). the Studied Operating Conditions Varied in Superficial Gas Velocity (Up to 0.3 M/s), Pressure (Up to 10 Bar), and Solids Concentration (Up to 25 Vol %). the Effects of These Variables on Heat Transfer Coefficients Are Discussed and Analyzed. the Increase in Pressure Tended to Reduce the Heat Transfer Coefficient, While the Increase in Solids Loading Enhanced the Heat Transfer …
Airlift Column Photobioreactors For Porphyridium Sp. Culturing: Part Ii. Verification Of Dynamic Growth Rate Model For Reactor Performance Evaluation, Hu Ping Luo, Muthanna H. Al-Dahhan
Airlift Column Photobioreactors For Porphyridium Sp. Culturing: Part Ii. Verification Of Dynamic Growth Rate Model For Reactor Performance Evaluation, Hu Ping Luo, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
Dynamic Growth Rate Model Has Been Developed to Quantify the Impact of Hydrodynamics on the Growth of Photosynthetic Microorganisms and to Predict the Photobioreactor Performance. Rigorous Verification of Such Reactor Models, However, is Rare in the Literature. in This Part of Work, Verification of a Dynamic Growth Rate Model Developed in Luo and Al-Dahhan (2004) [Biotech Bioeng 85(4): 382-393.] Was Attempted using the Experimental Results Reported in Part I of This Work and Results from Literature. the Irradiance Distribution Inside the Studied Reactor Was Also Measured at Different Optical Densities and Successfully Correlated by the Lambert-Beer Law. When Reliable Hydrodynamic …