Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Missouri University of Science and Technology

2006

Biochemical and Biomolecular Engineering

Articles 1 - 12 of 12

Full-Text Articles in Engineering

The Influence Of Ultrasonic Setting On Fluoride Release From Glass Polyalkenoate Cements, N. Rushe, Mark R. Towler Sep 2006

The Influence Of Ultrasonic Setting On Fluoride Release From Glass Polyalkenoate Cements, N. Rushe, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of ultrasonic setting on fluoride release from glass polyalkenoate cements (GPC) were investigated. Cements based on two different aluminosilicate glasses that contained silica, alumina, phosphate, and strontia were used for the experiment. A series of GPCs were examined to show that increased release F- ion occurs, regardless of GPC composition. The results show that there is a greater release of fluoride from the ultrasonically set samples than those set chemically, regardless of the chemical composition. The snap set caused by the ultrasound is likely to be due to a combination of cavitation, improved mixing of the constituents, …

Go to article

Flow Regime Identification In A Bubble Column Based On Both Statistical And Chaotic Parameters Applied To Computed Tomography Data, Stoyan Nedeltchev, Ashfaq Shaikh, Muthanna H. Al-Dahhan Sep 2006

Flow Regime Identification In A Bubble Column Based On Both Statistical And Chaotic Parameters Applied To Computed Tomography Data, Stoyan Nedeltchev, Ashfaq Shaikh, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Kolmogorov Entropy (KE) Algorithm Was Applied Successfully to Single Source Γ-Ray Computed Tomography (CT) Data Measured in a 0.162 M ID Bubble Column Equipped with a Perforated Plate Distributor (163 Holes · Ø 1.32 Mm). Dried Air Was Used as the Gas Phase and Therminol LT (ΡL = 886 Kg M-3, ΜL = 0.88 · 10-3 Pa S, Σ = 17 · 10-3 N M-1) Was Used as a Liquid Phase. Three Different Pressures, P, of 0.1, 0.4, and 1.0 MPa Were Examined. at Each Pressure the Superficial Gas Velocity, UG, Was Increased Stepwise by Steps of 0.01 Ms-1 …

Go to article

Influence Of Two Changes In The Composition Of An Acrylic Bone Cement On Some Of Its Properties: The Case Of Surgical Simplex® P, S. Madigan, Mark R. Towler, G. Lewis Sep 2006

Influence Of Two Changes In The Composition Of An Acrylic Bone Cement On Some Of Its Properties: The Case Of Surgical Simplex® P, S. Madigan, Mark R. Towler, G. Lewis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Influence of two changes in the composition of a self-curing acrylic bone cement on some of its properties are discussed. Acrylic bone cements are widely used in orthopedic surgery for the fixation of joint prosthesis and in vertebroplasty and kyphoplasty for the stabilization and augmentation of fractured vertebrae. The cement's curing process is the result of a free-radical polymerization of a mixture of poly (methyl 1 methacrylate) [PMMA] containing powder and a liquid monomer that has methyl methacrylate (MMA) in it. It is initiated by the decomposition of benzoyl peroxide (BPO) in the powder, activated by a tertiary amine in …

Go to article

Calcium And Zinc Ion Release From Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Mark R. Towler, S. Kenny, D. Boyd, T. Pembroke, M. Buggy, A. Guida, R. G. Hill Sep 2006

Calcium And Zinc Ion Release From Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Mark R. Towler, S. Kenny, D. Boyd, T. Pembroke, M. Buggy, A. Guida, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

Calcium and zinc ion release from hydroxyapatite-zinc oxide-poly (acrylic acid) (HAZnO-PAA) composite cements into deionised water was investigated as a function of HA content, PAA concentration, PAA molecular weight and maturation time. At any given maturation time, zinc ion release was constant until the HA content was at the maximum loading (60 wt%) resulting in the cement matrix breaking up, allowing exacerbated ion release. The calcium ion release increased with increased HA content in the composite until the maximum loading where the release drops off. Up to this point, the release of both ionic species was proportional to square root …

Go to article

Methane Production In A 100-L Upflow Bioreactor By Anaerobic Digestion Of Farm Waste, Abhijeet P. Borole, K. Thomas Klasson, Whitney Ridenour, Justin Holland, Khursheed Karim, Muthanna H. Al-Dahhan Jun 2006

Methane Production In A 100-L Upflow Bioreactor By Anaerobic Digestion Of Farm Waste, Abhijeet P. Borole, K. Thomas Klasson, Whitney Ridenour, Justin Holland, Khursheed Karim, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Manure Waste from Dairy Farms Has Been Used for Methane Production for Decades, However, Problems Such as Digester Failure Are Routine. the Problem Has Been Investigated in Small Scale (1-2 L) Digesters in the Laboratory; However, Very Little Scale-Up to Intermediate Scales Are Available. We Report Production of Methane in a 100-L Digester and the Results of an Investigation into the Effect of Partial Mixing Induced by Gas Upflow/recirculation in the Digester. the Digester Was Operated for a Period of About 70 D (With 16-D Hydraulic Retention Time) with and Without the Mixing Induced by Gas Recirculation through an Internal …

Go to article

The Antibacterial Effects Of Zinc Ion Migration From Zinc-Based Glass Polyalkenoate Cements, D. Boyd, H. Li, D. A. Tanner, Mark R. Towler, J. G. Wall Jun 2006

The Antibacterial Effects Of Zinc Ion Migration From Zinc-Based Glass Polyalkenoate Cements, D. Boyd, H. Li, D. A. Tanner, Mark R. Towler, J. G. Wall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Zinc-based glass polyalkenoate cements have been synthesised and their potential use in orthopaedic applications investigated. Zinc ions were released from the materials in a rapid burst over the first 24 h after synthesis, with the release rate falling below detectable levels after 7 days. Cement-implanted bone samples were prepared, and the released zinc was shown, using energy dispersive X-ray analysis, to penetrate from the cement into the adjacent bone by up to 40 μm. Finally, the cements exhibited antibacterial activity against Streptococcus mutans and Actinomyces viscosus that reflected the pattern of zinc release, with the inhibition of growth greatest shortly …

Go to article

An Investigation Into The Structure And Reactivity Of Calcium-Zinc-Silicate Ionomer Glasses Using Mas-Nmr Spectroscopy, D. Boyd, Mark R. Towler, R. V. Law, R. G. Hill May 2006

An Investigation Into The Structure And Reactivity Of Calcium-Zinc-Silicate Ionomer Glasses Using Mas-Nmr Spectroscopy, D. Boyd, Mark R. Towler, R. V. Law, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of Glass Polyalkenoate Cements (GPCs) for orthopaedic applications is retarded by the presence in the glass phase of aluminum, a neurotoxin. Unfortunately, the aluminum ion plays an integral role in the setting process of GPCs and its absence is likely to hinder cement formation. However, the authors have previously shown that aluminum-free GPCs may be formulated based on calcium zinc silicate glasses and these novel materials exhibit significant potential as hard tissue biomaterials. However, there is no data available on the structure of these glasses. 29Si MAS-NMR, differential thermal analysis (DTA), X-ray diffraction (XRD), and network crosslink density …

Go to article

Gas Holdup In Trayed Bubble Column Reactors, Javier Alvaré, Muthanna H. Al-Dahhan Apr 2006

Gas Holdup In Trayed Bubble Column Reactors, Javier Alvaré, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Sectionalization of Conventional Bubble Columns by Perforated Trays into Trayed Bubble Columns (TBCs) Has Much Potential in Biochemical and Petroleum Refining Processes, as an Effective Way to Improve the Gas-Liquid Contacting Efficiency and Reduce the Liquid Back mixing. in This Work, the Effects of Tray Geometry, Superficial Gas Velocity, and Superficial Liquid Velocity on the overall Gas Holdup Have Been Investigated. It Was Determined that the Trays Significantly Increase the overall Gas Holdup. the Tray Hole Diameter and Superficial Gas Velocity Were Determined to Be the Most Important Factors. © 2006 American Chemical Society.

Go to article

Ultrasonically Set Glass Polyalkenoate Cements For Orthodontic Applications, D. A. Tanner, N. Rushe, Mark R. Towler Apr 2006

Ultrasonically Set Glass Polyalkenoate Cements For Orthodontic Applications, D. A. Tanner, N. Rushe, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

There is an accepted clinical requirement for a luting cement that can be command set upon satisfactory placement of an orthodontic appliance onto dentition. This work evaluates the suitability of ultrasound, imparted from a dental scaler, as a potential mechanism for achieving this. The net setting times and subsequent compressive strengths of a range of commercial and experimental glass polyalkenoate cements (GPCs) were evaluated, using modified ISO 9917 methods, when set both chemically and by ultrasound. The ultrasound was applied to the GPC through an orthodontic brace. It was possible to command set GPCs by the application of five to …

Go to article

Optimisation Of The Composition Of An Acrylic Bone Cement: Application To Relative Amounts Of The Initiator And The Activator/Co-Initiator In Surgical Simplex®P, S. Madigan, M. R. Towler, G. Lewis Apr 2006

Optimisation Of The Composition Of An Acrylic Bone Cement: Application To Relative Amounts Of The Initiator And The Activator/Co-Initiator In Surgical Simplex®P, S. Madigan, M. R. Towler, G. Lewis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In cemented arthroplasties, the two-part self-curing acrylic bone cement is currently the only material used for anchoring the total joint replacement to the contiguous bone. In virtually all commercially available formulations of this cement, the agents used for the initiation and activation/co-initiation of the radical polymerisation reaction are benzoyl peroxide (BPO) and N, N dimethyl-paratoluidine (DMPT), respectively. There are no reports in the open literature on the rationale for the amounts of these and other constituents in the formulations of the cement. Given the concerns that have been raised in the literature regarding the effect of residual DMPT on the …

Go to article

Liquid Phase Mixing In Trayed Bubble Column Reactors, Javier Alvaré, Muthanna H. Al-Dahhan Mar 2006

Liquid Phase Mixing In Trayed Bubble Column Reactors, Javier Alvaré, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Compartmentalization of Conventional Bubble Columns by Perforated Trays Constitutes a Very Effective Method to Reduce the Liquid Back mixing. the Effect of Tray Design and Operating Conditions on the overall Liquid Mixing Was Studied in a Bench-Scale Trayed Bubble Column. the Extent of Liquid Back mixing in the Column Was Investigated in Light of Liquid-Phase Tracer Response Experiments. in Average, a Three-Fold Reduction in the Liquid Back mixing Was Achieved in the Trayed Column as Compared to the Column Without the Trays. Moreover, the Tray Open Area and the Superficial Liquid Velocity Were Found to Have the Strongest Effects …

Go to article

Phase Distribution In An Upflow Monolith Reactor Using Computed Tomography, M. (Muthanna) H. Al-Dahhan, A. Kemoun, A. R. Cartolano Feb 2006

Phase Distribution In An Upflow Monolith Reactor Using Computed Tomography, M. (Muthanna) H. Al-Dahhan, A. Kemoun, A. R. Cartolano

Chemical and Biochemical Engineering Faculty Research & Creative Works

Computed Tomography (CT) is Known to Be a Viable Technique for Determining Flow Maldistribution in Two-Phase Flow through Packed Beds. in This Study, Gamma Ray Computed Tomography Has Been Used to Quantify the Flow Distribution in a Monolith Catalytic Bed, with Water as the Liquid Phase and Air as the Gas Phase, Flowing Co-Currently Upward. the Flow Conditions Were Selected to Bracket Some Commercially Viable Operating Conditions for Such Reactors. in the Monolith Core Region, Fairly Uniform Flow Distribution Has Been Obtained for All the Flow Conditions Used. This Distribution is Quantified using the Standard Deviation of the Holdup Distribution. …

Go to article