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Articles 301 - 330 of 691

Full-Text Articles in Biochemical and Biomolecular Engineering

Degradable Borate Glass Polyalkenoate Cements, L. Shen, A. Coughlan, Mark R. Towler, M. Hall Jan 2014

Degradable Borate Glass Polyalkenoate Cements, L. Shen, A. Coughlan, Mark R. Towler, M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) containing aluminum-free borate glasses having the general composition Ag2O-Na2O-CaO-SrO-ZnO- TiO2-B2O3 were evaluated in this work. An initial screening study of sixteen compositions was used to identify regions of glass formation and cement compositions with promising rheological properties. The results of the screening study were used to develop four model borate glass compositions for further study. A second round of rheological experiments was used to identify a preferred GPC formulation for each model glass composition. The model borate glasses containing higher levels of TiO2 (7.5 mol %) …

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Stereoselective Transformations Of Α-Trifluoromethylated Ketoximes To Optically Active Amines By Enzyme-Nanometal Cocatalysis: Synthesis Of (S)-Inhibitor Of Phenylethanolamine N-Methyltransferase, Guilin Cheng, Qi Wu, Zeyu Shang, Xinhua Liang, Xianfu Lin Jan 2014

Stereoselective Transformations Of Α-Trifluoromethylated Ketoximes To Optically Active Amines By Enzyme-Nanometal Cocatalysis: Synthesis Of (S)-Inhibitor Of Phenylethanolamine N-Methyltransferase, Guilin Cheng, Qi Wu, Zeyu Shang, Xinhua Liang, Xianfu Lin

Chemical and Biochemical Engineering Faculty Research & Creative Works

One-pot cascade synthesis of optically active α-trifluoro methylated amines directly from ketoximes was accomplished with the use of Candida antarctica lipase B and catalysts prepared by atomic layer deposition (ALD). Compared to the commercial palladium catalyst, the ALD-prepared catalysts showed much higher activity and afforded various α-trifluoro methylated amides in good yields and with high enantioselectivity. One of the enantiopure amides was further hydrolyzed into the corresponding amine, which was treated as a crucial starting material for total synthesis of (S)-inhibitor of phenyl ethanolamine N-methyltransferase without loss of chiral information. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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Characteristics Of Glass Ionomer Cements Composed Of Glass Powders In Cao-Sro-Zno-Sio2 System Prepared By Two Different Synthetic Routes, Ill Yong Kim, Chikara Ohtsuki, Aisling Coughlan, Lana Placek, Anthony W. Wren, Mark R. Towler Dec 2013

Characteristics Of Glass Ionomer Cements Composed Of Glass Powders In Cao-Sro-Zno-Sio2 System Prepared By Two Different Synthetic Routes, Ill Yong Kim, Chikara Ohtsuki, Aisling Coughlan, Lana Placek, Anthony W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass ionomer cements (GICs) are composed of an acid degradable glass, polyacrylic acid and water. Sol-gel processing to prepare the glass phase has certain advantages, such as the ability to employ lower synthesis temperatures than melt quenching and glasses that are reported to have higher purity. A previous study reported the effects of glass synthesis route on GIC fabrication. However, in that study, the sol-gel derived glass exhibited a reduced concentration of cations. This study investigates increasing the cation content of a sol-gel derived glass, 12CaO·4SrO·36ZnO·48SiO2 (molar ratio) by heating before aging to reduce dissolution of cations. This glass …

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Relating Ph And Ion Release From Ga2o3-Na 2o-Cao-Zno-Sio2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, Mark R. Towler, M. M. Hall Nov 2013

Relating Ph And Ion Release From Ga2o3-Na 2o-Cao-Zno-Sio2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, Mark R. Towler, M. M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three glasses were designed for this study, including one Ga-free glass (Control), and two Ga-containing glasses (TGa-1, TGa-2). In the Ga-containing glasses, Ga2O3 is included at the expense of ZnO. This study focuses on the relation between pH and ion concentration present in solution in which these bioactive glasses have been submerged for periods of 1, 7, and 14 days. © 2013 IEEE.

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Gallium Containing Glass Polyalkenoate Bone Cements: Ion Release And E. Coli Inhibition, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler Nov 2013

Gallium Containing Glass Polyalkenoate Bone Cements: Ion Release And E. Coli Inhibition, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Glass Polyalkenoate Cement (GPC) series (LCon., LGa-1 and LGa-2) containing gallium (Ga) and a 50 wt% addition of E11 polyacrylic acid (PAA), previously developed, was evaluated for ion release, specifically Si, Ca, Zn and Ga, and E. coli inhibition. The maximum inhibition was observed in the t = 0 samples and was 0.35 mm for LCon. and 0.65 mm for LGa-1 and LGa-2. © 2013 IEEE.

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Biocompatibility Of Cao-Na2o-Sio2/Tio2 Glass Ceramic Scaffolds For Orthopaedic Applications, A. W. Wren, A. Coughlan, K. E. Smale, S. T. Misture, B. P. Mahon, O. M. Clarkin, Mark R. Towler Nov 2013

Biocompatibility Of Cao-Na2o-Sio2/Tio2 Glass Ceramic Scaffolds For Orthopaedic 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

This work aims to determine the effect of substituting TiO2 for SiO2 in a 0.62SiO2-Na2O-0.24CaO based glass-ceramic scaffold. High temperature X-ray Diffraction (HT-XRD) was used to determine the sintering temperature (700oC). Both optical microscopy and x-ray micotomography was used to determine the average pore size (540-680ìm) of each scaffold. Cytocompatibility of each scaffold was conducted using murine mesenchymal stem cells. © 2013 IEEE.

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An Investigation Into The Structure And Properties Of Cao-Zno-Sio 2-Tio2-Na2o Bioactive Glass/Hydroxyapatite Composite, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren Nov 2013

An Investigation Into The Structure And Properties Of Cao-Zno-Sio 2-Tio2-Na2o Bioactive Glass/Hydroxyapatite Composite, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Effect of the addition of CaO-ZnO-SiO2-TiO2-Na2O glass as a reinforcing phase on properties of hydroxyapatite/glass composites was investigated. The addition of the glass caused the decomposition of HA phase to tricalcium phosphate, inhibiting densification in the HA/glass composites. However, depending on the glass concentration, some of the glass can act as a sintering aid enhancing the densification in the composites. © 2013 IEEE.

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Encapsulation Of Supported Metal Nanoparticles With An Ultra-Thin Porous Shell For Size-Selective Reactions, Zeyu Shang, Rajankumar L. Patel, Brian W. Evanko, Xinhua Liang Oct 2013

Encapsulation Of Supported Metal Nanoparticles With An Ultra-Thin Porous Shell For Size-Selective Reactions, Zeyu Shang, Rajankumar L. Patel, Brian W. Evanko, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

A novel nanostructured catalyst with an ultra-thin, porous shell obtained from the thermal decomposition of an aluminum alkoxide film deposited by molecular layer deposition for size-selective reactions was developed. The molecular sieving capability of the porous metal oxide films was verified by examining the liquid-phase hydrogenation of n-hexene versus cis-cyclooctene. © 2013 The Royal Society of Chemistry.

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Gas Barrier And Mechanical Properties Of Crosslinked Ethylene Vinyl Acetate Nanocomposites, S. A. Ahmad Ramazani, M. Shafiee, Hossein Abedsoltan, A. Shafiee Oct 2013

Gas Barrier And Mechanical Properties Of Crosslinked Ethylene Vinyl Acetate Nanocomposites, S. A. Ahmad Ramazani, M. Shafiee, Hossein Abedsoltan, A. Shafiee

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this research, the effects of crosslinking agent and clay content on the morphology, barrier and mechanical properties of ethylene vinyl acetate-organoclay nanocomposites prepared by solution method were studied. Dicumyl peroxide has been used as crosslinking agent. The morphology of the prepared nanocomposites was investigated using wide-angle X-ray diffraction and transmission electron microscopy. Wide-angle X-ray diffraction and transmission electron microscopy indicated that the prepared nanocomposites had predominantly intercalated morphologies. The obtained results of permeability tests showed that the permeability of ethylene vinyl acetate films dramatically decreases with addition of organoclay and dicumyl peroxide. Mechanical tests showed that tensile modulus and …

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Stabilizing Nanostructured Solid Oxide Fuel Cell Cathode With Atomic Layer Deposition, Yunhui Gong, Diego Palacio, Xueyan Song, Rajankumar L. Patel, Xinhua Liang Sep 2013

Stabilizing Nanostructured Solid Oxide Fuel Cell Cathode With Atomic Layer Deposition, Yunhui Gong, Diego Palacio, Xueyan Song, Rajankumar L. Patel, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

We demonstrate that the highly active but unstable nanostructured intermediate-temperature solid oxide fuel cell cathode, La0.6Sr0.4CoO3-δ (LSCo), can retain its high oxygen reduction reaction (ORR) activity with exceptional stability for 4000 h at 700 C by overcoating its surfaces with a conformal layer of nanoscale ZrO2 films through atomic layer deposition (ALD). The benefits from the presence of the nanoscale ALD-ZrO2 overcoats are remarkable: a factor of 19 and 18 reduction in polarization area-specific resistance and degradation rate over the pristine sample, respectively. The unique multifunctionality of the ALD-derived nanoscaled ZrO2 overcoats, …

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Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Ion Release, Biocompatibility And Antibacterial Properties, A. W. Wren, A. Coughlan, M. M. Hall, M. J. German, Mark R. Towler Sep 2013

Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Ion Release, Biocompatibility And Antibacterial Properties, A. W. Wren, A. Coughlan, M. M. Hall, M. J. German, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Ion Release and biocompatibility of a CaO-SrO-ZnO-SiO2 (BT 101) based glass polyalkenoate cement (GPC) was compared against commercial GPCs, Fuji IX and Ketac Molar. The radiopacity (R) was similar for each material, 2.0-2.8. Ion release was evaluated on each material over 1, 7, 30 and 90 days. BT 101 release included Ca (23 mg/L), Sr (23 mg/L) Zn (13 mg/L), Si (203 mg/L). Fuji IX release includes Ca (0.7 mg/L), Al (3 mg/L) Si (26 mg/L), Na (60 mg/L) and P (0.5 mg/L) while Ketac Molar release includes Ca (1 mg/L), Al (0.6 mg/L) Si (23 mg/L), Na (76 …

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Atomic Layer Deposited Highly Dispersed Platinum Nanoparticles Supported On Non-Functionalized Multiwalled Carbon Nanotubes For The Hydrogenation Of Xylose To Xylitol, Xinhua Liang, Chengjun Jiang Sep 2013

Atomic Layer Deposited Highly Dispersed Platinum Nanoparticles Supported On Non-Functionalized Multiwalled Carbon Nanotubes For The Hydrogenation Of Xylose To Xylitol, Xinhua Liang, Chengjun Jiang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Highly dispersed platinum nanoparticles were deposited on gram quantities of non-functionalized multiwalled carbon nanotubes (MWCNTs) by atomic layer deposition (ALD) in a fluidized bed reactor at 300°C. (Methylcyclopentadienyl) trimethylplatinum and oxygen were used as precursors. The results of TEM analysis showed that ∼1.3 nm Pt nanoparticles were highly dispersed on non-functionalized MWCNTs. The porous structures of MWCNTs did not change with the deposition of Pt nanoparticles. For comparison, the commercial 3 wt.% Pt/C catalyst was also characterized. The ALD-prepared Pt/MWCNT was used for the hydrogenation of xylose to xylitol. The ALD-prepared Pt/MWCNT showed the best catalytic performance with 100 % …

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Scale-Up Of Bubble Column Reactors: A Review Of Current State-Of-The-Art, Ashfaq Shaikh, Muthanna H. Al-Dahhan Jun 2013

Scale-Up Of Bubble Column Reactors: A Review Of Current State-Of-The-Art, Ashfaq Shaikh, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

In Multiphase Flow Reaction Systems, in General, an Extrapolation of Small Diameter Behavior to Larger Ones is Always an Important and Challenging Task. the Critical Issue in Such an Extrapolation Remains to Be Mixing and Hydrodynamic Characteristics. It Needs Reliable Similarity Criteria that Would Result in Similar Mixing and Hydrodynamics and Hence Transport and Performance in Two Different Scales. Numerous Experimental and Computational Studies Have Been Performed to Investigate the Flow Behavior of Bubble Column Reactors for a Proper Design and Scale-Up. Experimental Techniques Vary from Simple Visual Observation to More Advanced Noninvasive Diagnostic Techniques. on Computational Front the Progress …

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Characterisation Of Ga2o3-Na2o-Cao-Zno- Sio2 Bioactive Glasses, A. W. Wren, T. Keenan, A. Coughlan, F. R. Laffir, D. Boyd, Mark R. Towler, M. M. Hall Jun 2013

Characterisation Of Ga2o3-Na2o-Cao-Zno- Sio2 Bioactive Glasses, A. W. Wren, T. Keenan, A. Coughlan, F. R. Laffir, D. Boyd, Mark R. Towler, M. M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

The structural role of Gallium (Ga) is investigated when substituted for Zinc (Zn) in a 0.42SiO2-0.40-xZnO-0.10Na2O-0.08CaO glass series, (where x = 0.08). Each starting material was amorphous, and the network connectivity (NC) was calculated assuming Ga acts as both a network modifier (1.23), and also as a network former. Assuming a network forming role for Ga the NC increased with increasing Ga concentration throughout the glass series (Control 1.23, TGa-1 2.32 and TGa-2 3.00). X-ray photoelectron spectroscopy confirmed both composition and correlated NC predictions. Raman spectroscopy was employed to investigate Q-structure and found that a shift …

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Increasing Round Trip Efficiency Of Hybrid Li-Air Battery With Bifunctional Catalysts, Kan Huang, Yunfeng Li, Yangchuan Xing May 2013

Increasing Round Trip Efficiency Of Hybrid Li-Air Battery With Bifunctional Catalysts, Kan Huang, Yunfeng Li, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

Previously it was shown that Pt as cathode catalyst has a large overpotential during charge in rechargeable hybrid Li-air battery with sulfuric acid catholyte. This article demonstrates that a bifunctional catalyst composed of Pt and IrO2 supported on carbon nanotubes can address this problem. The specially designed and synthesized bifunctional catalyst showed significant overpotential reduction and achieved a round-trip energy efficiency of 81% after 10 cycles, higher than many achieved in aprotic Li-O2 batteries. The hybrid Li-air battery was discharged and recharged for 20 cycles at 0.2 mA/cm2, showing a fairly stable cell performance. A specific capacity of 306 mAh/g …

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Aluminium-Free Glass Polyalkenoate Cements: Ion Release And In Vitro Antibacterial Efficacy, A. W. Wren, J. P. Hansen, S. Hayakawa, Mark R. Towler May 2013

Aluminium-Free Glass Polyalkenoate Cements: Ion Release And In Vitro Antibacterial Efficacy, A. W. Wren, J. P. Hansen, S. Hayakawa, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) have exhibited potential as bone cements. This study investigates the effect of substituting TiO2 for SiO2 in the glass phase and the subsequent effect on cement rheology, mechanical properties, ion release and antibacterial properties. Glass characterization revealed a reduction in glass transition temperature (Tg) from 685 to 669 C with the addition of 6 mol % TiO2 (AT-2). Magic angle spinning nuclear magnetic resonance (MAS-NMR) revealed a shift from -81 ppm to -76pmm when comparing a Control glass to AT-2, indicating de-polymerization of the Si network. The incorporation of TiO2 …

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Sensor Application Of Poly (Ethylene Glycol) Diacrylate Hydrogels Chemically-Anchored On Polymer Surface, Zhan Gao, Chang-Soo Kim, David B. Henthorn Apr 2013

Sensor Application Of Poly (Ethylene Glycol) Diacrylate Hydrogels Chemically-Anchored On Polymer Surface, Zhan Gao, Chang-Soo Kim, David B. Henthorn

Electrical and Computer Engineering Faculty Research & Creative Works

We demonstrate a device process combining two photo patternable polymers, poly (ethylene glycol) (PEG)-diacrylate-based-hydrogel and epoxy-based photoresist SU-8, to implement an optofluidic bioanalytical platform through a surface anchoring technique. As an exemplary sensor application, optical dissolved oxygen sensors are fabricated and their performance characterized. The PEG-rich hydrogel is used as a matrix material for the immobilization of oxygen-responsive fluorophore, dichlorotris (1, 10-phenanthroline) ruthenium (II) hydrate. This hydrogel is chemically anchored on the surface of negative-tone photoresist, SU-8, through a free radical reaction in which 1-hydroxycyclohexyl phenyl ketone served as the surface bound photo initiator. The sensor exhibits a reversible Stern-Volmer …

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Method Of Purifying Crude Noscapine, Benjamin M. Marshall, Keith Tomazi Mar 2013

Method Of Purifying Crude Noscapine, Benjamin M. Marshall, Keith Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The invention provides a method for separating noscapine from an opium source without substantially changing the color of the noscapine.

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Carbothermal Synthesis Of Titanium Oxycarbide As Electrocatalyst Support With High Oxygen Evolution Reaction Activity, Kan Huang, Yunfeng Li, Yangchuan Xing Feb 2013

Carbothermal Synthesis Of Titanium Oxycarbide As Electrocatalyst Support With High Oxygen Evolution Reaction Activity, Kan Huang, Yunfeng Li, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

Carbothermal reduction of semiconducting TiO2 into highly conductive titanium oxycarbide (TiOxCy) was investigated. The thermally produced uniform carbon layer on TiO2 (Degussa P25) protects the TiO2 nanoparticles from sintering and, at the same time, supplies the carbon source for doping TiO2 with carbon. At low temperatures (e.g., 700 °C), carbon only substitutes part of the oxide and distorts the TiO2 lattice to form TiO2-xCx with only substitutional carbon. When the carbon-doped TiO2 is annealed at a higher temperature (1100 °C), x-ray diffraction and x-ray photoelectron spectroscopy results showed that TiOxCy, a solid …

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Numerical Evaluation Of The Stability Of Stationary Points Of Index-2 Differential-Algebraic Equations: Applications To Reactive Flash And Reactive Distillation Systems, D. A. Harney, T. K. Mills, N. L. Book Feb 2013

Numerical Evaluation Of The Stability Of Stationary Points Of Index-2 Differential-Algebraic Equations: Applications To Reactive Flash And Reactive Distillation Systems, D. A. Harney, T. K. Mills, N. L. Book

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamic behavior of many chemical processes can be represented by an index-2 system of differential-algebraic equations. This index can be reduced by differentiation, but unfortunately the index reduced systems are not guaranteed to possess the same stability characteristics as that of the original system. When the set of differential-algebraic equations can be written in Hessenberg form, the matrix pencil of the linearized system can be used to directly evaluate the stability of a steady state without the need for index reduction. Direct evaluations of stability of reactive flash and reactive distillation are presented. It is also shown that a …

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A New Method For Online Flow Regime Monitoring In Bubble Column Reactors Via Nuclear Gauge Densitometry, Ashfaq Shaikh, Muthanna H. Al-Dahhan Feb 2013

A New Method For Online Flow Regime Monitoring In Bubble Column Reactors Via Nuclear Gauge Densitometry, Ashfaq Shaikh, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

In the Current Work, Nuclear Gauge Densitometry (NGD), Which is Commercially Available and Industrially Used for Liquid/slurry Level Measurement and Control, Has Been Employed to Identify Fingerprints of the Prevailing Hydrodynamic Flow Regime. Experiments Were Performed using an Air-Water System in 0.1012. M Diameter and 1.2. M Long Bubble Column at Ambient Pressure. the Superficial Gas Velocities Were Varied from 1. Cm/s to 12. Cm/s with an Interval of 0.5. Cm/s Near Transition Region. the Flow Regime Boundaries Were Defined using the Conventional Methods of Flow Regime Demarcation Such as the Change in the Slope of the overall Gas Holdup …

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Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Glass Structure And Physical Properties, A. W. Wren, A. Coughlan, F. R. Laffir, Mark R. Towler Feb 2013

Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Glass Structure And Physical Properties, A. W. Wren, A. Coughlan, F. R. Laffir, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) have previously been considered for orthopedic applications. A Zn-GPC (BT 101) was compared to commercial GPCs (Fuji IX and Ketac Molar) which have a setting chemistry analogous to BT 101. Handling properties (working, Tw and setting, Ts times) for BT 101 were shorter than the commercial GPCs. BT 101 also had a higher setting exotherm (Sx - 34 °C) than the commercial GPCs (29 °C). The maximum strengths for BT 101, Fuji IX, and Ketac Molar were 75, 238, and 216 MPa (compressive, σc), and 34, 54, and 62 MPa (biaxial …

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Hydrodynamics Of Pilot-Scale Bubble Columns: Effect Of Internals, Ahmed A. Youssef, Mohamed E. Hamed, Joshua T. Grimes, Muthanna H. Al-Dahhan, Milorad P. Duduković Jan 2013

Hydrodynamics Of Pilot-Scale Bubble Columns: Effect Of Internals, Ahmed A. Youssef, Mohamed E. Hamed, Joshua T. Grimes, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Gas Holdup and Bubble Characteristics Are Key Parameters that Affect the Performance of Bubble Columns. an Experimental Study of the Effect of Heat Exchanging Internals on the Gas Holdup, Bubble Dynamics, and their Radial Profiles is Performed. an Air-Water System is Used in a Plexiglas Column 45 Cm (18 In.) in Diameter. Internals Configurations Mimicking Those Typical for the Liquid-Phase Methanol Synthesis and Fischer-Tropsch Process and Covering 5% and 25%, Respectively, of the Total Cross-Sectional Area of the Column, Are Investigated. High Superficial Gas Velocities that Fall within the Churn Turbulent Flow Regime, Which Are of Interest for Most …

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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 Dec 2012

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- …

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Colorimetric Oxygen Imaging And Quantification With Easily Accessible Optical Devices, Satya Achanta, Sanghan Park, Chang-Soo Kim Dec 2012

Colorimetric Oxygen Imaging And Quantification With Easily Accessible Optical Devices, Satya Achanta, Sanghan Park, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Optical oxygen imaging is essential in monitoring two-dimensional analysis of oxygen distribution. Two easily accessible optical devices were used for oxygen analysis to demonstrate the feasibility of an innovatively simple method. a light panel screen with light-emitting diode (LED) backlight was used as a light source to excite a luminophore film responsive to oxygen. Meso-scale fluidic sensor platform was prepared using porphyrin complex (PtOEP) as the luminophore embedded within ethyl cellulose (EC) polymer matrix. Green LED light uniformly displayed from the light panel excited the luminophore film to exhibit two-dimensional luminescence distribution corresponding to wet gaseous oxygen. a color camera …

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A Hybrid Li-Air Battery With Buckypaper Air Cathode And Sulfuric Acid Electrolyte, Yunfeng Li, Kan Huang, Yangchuan Xing Oct 2012

A Hybrid Li-Air Battery With Buckypaper Air Cathode And Sulfuric Acid Electrolyte, Yunfeng Li, Kan Huang, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

We demonstrate a type of carbon nanotube based buckypaper cathode in a hybrid electrolyte Li-air battery (HyLAB) that showed outstanding discharging performances. the HyLAB has sulfuric acid as the catholyte and a large active electrode area (10 cm 2). the active cathode layer was made from a buckypaper with 5 wt.% Pt supported on carbon nanotubes (Pt/CNTs) for oxygen reduction and evolution. a similar cathode was constructed with a catalyst of 5 wt.% Pt supported on carbon black (Pt/CB). It is demonstrated that sulfuric acid can achieve high discharging current densities while maintaining relatively high cell potentials. the cell with …

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Fabrication Of Ph- Or Temperature-Responsive Single Wall Carbon Nanotubes Via A Graft From Photopolymerization, Pu Zhang, David B. Henthorn Oct 2012

Fabrication Of Ph- Or Temperature-Responsive Single Wall Carbon Nanotubes Via A Graft From Photopolymerization, Pu Zhang, David B. Henthorn

Chemical and Biochemical Engineering Faculty Research & Creative Works

An ultraviolet light initiated "graft from" polymerization method to fabricate polymer-functionalized single wall carbon nanotubes (SWNTs) with pendant pH- and temperature-responsive polymer chains is utilized. the attached polymer chains, formed from methacrylic acid and poly (ethylene glycol) methyl ether methacrylate monomers, are well established for its pH-responsive swelling/deswelling behavior. This special property was utilized here to control the aqueous dispersibility of the carbon nanotubes. Furthermore, poly(N-isopropylacrylamide), a temperature-responsive polymer, was utilized in the fabrication of SWNTs whose dispersibility was dependent on solution temperature. the morphology of the polymer-functionalized carbon nanotubes was characterized by scanning electron microscopy (SEM) before and after …

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Increasing Pt Oxygen Reduction Reaction Activity And Durability With A Carbon-Doped Tio 2 Nanocoating Catalyst Support, Kan Huang, Kotaro Sasaki, Radoslav R. Adzic, Yangchuan Xing Sep 2012

Increasing Pt Oxygen Reduction Reaction Activity And Durability With A Carbon-Doped Tio 2 Nanocoating Catalyst Support, Kan Huang, Kotaro Sasaki, Radoslav R. Adzic, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

We report a conductive TiO2 nanocoating on carbon nanotubes (CNTs) as a Pt electrocatalyst support that shows a significant enhancement in Pt catalyst activity and durability for the oxygen reduction reaction. by using CNTs as the substrate for TiO2 nanocoating, the nanoscale morphology of the oxide was retained during heat treatment. after carbon doping of the TiO2 nanocoating, X-ray photoelectron spectroscopy suggests a shift in the binding energy of Ti 2p, implying a suboxide formation. the X-ray absorption near-edge structure showed the mid-edge and post-edge up to 5010 eV, which are attributed to a 1s → 4p transition and promotion …

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Developing Novel Prognostic Biomarkers For Multivariate Fracture Risk Prediction Algorithms, Ernest K. Poku, Mark R. Towler, Niamh M. Cummins, Jeff D. Newman Sep 2012

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 …

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Gallium Containing Glass Polyalkenoate Anti-Cancerous Bone Cements: Glass Characterization And Physical Properties, A. W. Wren, A. Coughlan, L. Placek, Mark R. Towler Aug 2012

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) …

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