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Visible-Solar-Light-Driven Photocatalytic Degradation Of Phenol With Dye-Sensitized Tio2: Parametric And Kinetic Study, Pankaj Chowdhury, Jesus Moreira Del Rio, Hassan Gomaa, Ajay K. Ray

P

Phenol degradation with TiO2 photocatalyst under UV light is known to be an effective method. Under solar radiation, however, this approach does not receive adequate photons for catalyst activation, as the solar spectrum comprises mostly visible light (46%). In this study, we applied the dye-sensitization technique to prepare visible-light-active catalyst and used it under visible solar light generated from a solar simulator with a UV cutoff filter (λ > 420 nm) for phenol degradation. Eosin Y dye was used as a sensitizer for the TiO2 catalyst with a very low level of platinum as a cocatalyst. Triethanolamine was used as a …

Visible-Solar-Light-Driven Photocatalytic Degradation Of Phenol With Dye-Sensitized Tio2: Parametric And Kinetic Study, Pankaj Chowdhury, Jesus Moreira, Hassan Gomaa, Ajay Ray

PC

Phenol degradation with TiO2 photocatalyst under UV light is known to be an effective method. Under solar radiation, however, this approach does not receive adequate photons for catalyst activation, as the solar spectrum comprises mostly visible light (46%). In this study, we applied the dye-sensitization technique to prepare visible-light-active catalyst and used it under visible solar light generated from a solar simulator with a UV cutoff filter (λ > 420 nm) for phenol degradation. Eosin Y dye was used as a sensitizer for the TiO2 catalyst with a very low level of platinum as a cocatalyst. Triethanolamine was used as a …

Production Of Granola Breakfast Cereal By Fluidised Bed Granulation, Pankaj Pathare

Pankaj B Pathare

In the fluidised bed granulation process the effect of nozzle air pressure and binder spray rate on key aggregate quality attributes were studied. The experimental results show that a decrease in nozzle air pressure leads to larger mean granule size. The combination of lowest nozzle air pressure and lowest binder spray rate results in granules with the highest levels of hardness and crispness. The combination of low nozzle air pressure and low binder spray rate results in the least distribution span. Granola hardness was affected by nozzle air pressure. Nozzle air pressure and binder spray rate did not have significant …

Factorial Design Analysis For Dye-Sensitized Hydrogen Generation From Water, Pankaj Chowdhury, Hassan Gomaa, Ajay Ray

PC

A factorial design at two levels and four factors has been carried out in order to investigate the potential for hydrogen generation using Eosin Y-sensitized TiO2/Pt catalyst under visible solar light in presence of triethanolamine (TEOA) as electron donor. The solution pH was found to be a significant parameter, and was maintained at pH 7.0 throughout the investigation. Visible light irradiation time (I-time) showed highest positive effect on hydrogen generation followed by initial Eosin Y concentration (for dye-sensitization) and the TEOA concentration while Pt content (wt %) in TiO2 showed negative effect toward hydrogen generation. Experimental data were analyzed using …

Metamaterials On Parylene Thin Film Substrates: Design, Fabrication, And Characterization At Terahertz Frequency, Xianliang Liu, Samuel Macnaughton, David Shrekenhamer, Hu Tao, Selvapraba Selvarasah, Atcha Totachawattana, Richard Averitt, Mehmet Dokmeci, Sameer Sonkusale, Willie Padilla

Mehmet R. Dokmeci

We design, fabricate, and characterize terahertz (THz) resonant metamaterials on parylene free-standing thin film substrates. Several different metamaterials are investigated and our results show strong electromagnetic responses at THz frequencies ranging from 500 GHz to 2.5 THz. The complex frequency dependent dielectric properties of parylene are determined from inversion of reflection and transmission data, thus indicating that parylene is an ideal low loss substrate or coating material. The biostable and biocompatible properties of parylene coupled with the multifunctional exotic properties of metamaterials indicate great potential for medical purposes such as THz imaging for skin cancer detection.

The Yin And Yang Actions Of North American Ginseng Root In Modulating The Immune Function Of Macrophages, Chike Azike, Paul Charpentier, Jirui Hou, Hua Pei, Edmund Lui

Edmund M. K. Lui

BACKGROUND: Immuno-modulatory effects of ginseng, including both immuno-stimulatory and immuno-suppressive effects, have been widely reported. This study aims to determine whether the paradoxical immuno-modulatory effect is related to unique phytochemical profiles of different North American (NA) ginseng, namely aqueous (AQ) and alcoholic (ALC) extracts.

METHODS: AQ and ALC extracts were prepared and their immuno-bioactivity were studied in vitro in murine macrophages (Raw 264.7) through measuring the direct stimulatory production of pro-inflammatory mediator and cytokines as well as the suppression of lipopolysaccharide (LPS)-stimulatory response by the two extracts. Gel permeation chromatography was used to fractionate and isolate phytochemicals for characterization of …

Correlation Between Texture, Anisotropy, And Vector Magnetization Processes Investigated By Two-Dimensional Vector Vibrating Sample Magnetometry In Bao(Fe₂O₃)₆ Thin Film, Paul Ohodnicki, K. Goh, Michael Mchenry, Katherine Ziemer, Zhaohui Chen, C. Vittoria, Vincent Harris (1962-)

Vincent G. Harris

High ferromagnetic resonance frequencies and low linewidths in BaO(Fe₂O₃)₆ thin films are achieved by obtaining a low-dispersion of crystallite easy c axes normal to the film. X-ray diffraction and magnetic force microscopy are used to characterize texture and magnetic domain structure for a BaO(Fe₂O₃)₆ film deposited on (0001) SiC with a MgO (111) template layer. Strong c-axis texture normal to the film is observed resulting in strong uniaxial anisotropy. The consequent vector magnetization processes due to a combination of domain wall motion and magnetization rotation are characterized by two dimensional vector coil vibrating sample magnetometry (VVSM).

Ba-Hexaferrite Films For Next Generation Microwave Devices, Vincent Harris (1962-), Zhaohui Chen, Yajie Chen, Soack Yoon, Tomokuza Sakai, Anton Geiler, Aria Yang, Yongxue He, Katherine Ziemer, Nian Sun, C. Vittoria

Vincent G. Harris

Next generation magnetic microwave devices require ferrite films to be thick (>300 μm), self-biased (high remanent magnetization), and low loss in the microwave and millimeter wave bands. Here we examine recent advances in the processing of thick Ba-hexaferrite (M-type) films using pulsed laser deposition (PLD), liquid-phase epitaxy, and screen printing. These techniques are compared and contrasted as to their suitability for microwave materials processing and industrial production. Recent advances include the PLD growth of BaM on wide-band-gap semiconductor substrates and the development of thick, self-biased, low-loss BaM films by screen printing.

High-Speed Friction Measurements Using A Modified Surface Forces Apparatus, Younjin Min

Younjin Min

Methods of measuring friction forces in the surface forces apparatus (SFA) are presented for sliding velocities from <1 nm/s to >10 m/s. A feed-forward control (FFC) system for the piezoelectric bimorph slider attachment is introduced to allow experiments at velocities up to ~4 mm/s. For still higher speeds, a motor-driven rotating mini-disk setup using a pin-on-disk geometry is presented, with modifications to enable sliding velocities in the ranges 1 cm/s–5 m/s and 1–25 m/s. Example data sets demonstrate the applicability of the approach to modeling important tribological systems including hard-disk drives. We find that mechanical system parameters such as the resonant frequencies and …

Engineering Instructional Development: Programs, Best Practices, And Recommendations, Michael Prince, R. Felder, R. Brent

Michael J. Prince

No abstract provided.

Comparison Of Theory And Experiments For Dispersion In Homogeneous Porous Media, Mark Porter, Francisco Valdes-Parada, Brian Wood

Francisco J. Valdes-Parada

Modeling dispersion in homogeneous porous media with the convection–dispersion equation commonly requires computing effective transport coefficients. In this work, we investigate longitudinal and transverse dispersion coefficients arising from the method of volume averaging, for a variety of periodic, homogeneous porous media over a range of particle Péclet (Pep) numbers. Our objective is to validate the upscaled transverse dispersion coefficients and concentration profiles by comparison to experimental data reported in the literature, and to compare the upscaling approach to the more common approach of inverse modeling, which relies on fitting the dispersion coefficients to measured data. This work is unique in …

Effect Of Microreactor Geometry In Performance Of Catalytic Microreactor Of Hydrogen Production By Cfd Modeling, Mohsen Behnam, Ali Fazeli, Shohreh Fatemi, Yadolah Mortazavi, A. Khodadai

Ali Fazeli

Hydrogen production from steam reforming of methanol for fuel cell application was modeled in a wall coated micro channel reactor by CFD approach. Heat of steam reforming was supplied from catalytic total oxidation (TOX) of methanol in neighboring channel of steamreforming (SR) channel and conduct from TOX to SR channel through metal divider wall of the channels. Heat integration was compared in zigzag and straight geometry of microreactor by CFD modeling. The model is 2 dimensional, steady state and containing five zones: TOX fluid, TOX catalyst layer, steel wall of the channel, SR catalyst layer, SR fluid. Set of partial …

Building An Understanding Of Heat Transfer Concepts In Undergraduate Chemical Engineering Courses, Michael Prince, M. Vigeant, K. Nottis

Michael J. Prince

No abstract provided.

Theory And Computation Of Photopolymerization Induced Phase Transition And Morphology Development In Blends Of Crystalline Polymer And Photoreactive Monomer, Thein Kyu

Thein Kyu

A hypothetical phase diagram of a crystalline polymer/photoreactive monomer mixture has been calculated on the basis of phase field (PF) free energy of crystal solidification in conjunction with Flory-Huggins (FH) free energy of liquid-liquid demixing to guide the morphology development during photopolymerization of poly(ethylene oxide)/triacrylate blend. The self-consistent solution of the combined PF-FH theory exhibits a crystalline-amorphous phase diagram showing the coexistence of solid+liquid gap bound by the liquidus and solidus lines, followed by an upper critical solution temperature at a lower temperature. When photopolymerization was triggered in the isotropic region, i.e., slightly above the crystal melting transition temperatures, the …

A Preliminary Study On The Effectiveness Of Inquiry-Based Activities For Addressing Misconceptions Of Undergraduate Engineering Students, Michael Prince, M. Vigeant, K. Nottis

Michael J. Prince

No abstract provided.

Electrospinning Route For The Fabrication Of Pn Junction Using Nanofiber Yarns, Darrell Reneker

Darrell Hyson Reneker

Electrospinning is a simple, versatile, and cost effective method for generating nanoscale fibers, wires, and tubes. Nanowires and nanotubes could be important building blocks for nanoscale electronics, optoelectronics, and sensors as they can function as miniaturized devices as well as electrical interconnects. We report on a simple method to fabricate free standing ceramic nanofiber heterostructures, which exhibit rectifying behavior of a p-n junction

Production Of Meso-And Giga-Porous Zirconia Particles—An Improved Multi-Step Particle Aggregation Process, Abhinandan Pattanayak

Abhinandan Pattanayak

No abstract provided.

Saw Dust And Neem Bark As Low-Cost Natural Biosorbent For Adsorptive Removal Of Zn (Ii) And Cd (Ii) Ions From Aqueous Solutions, Tarun Naiya, Pankaj Chowdhury, Ashim Bhattacharya, Sudip Das

PC

The ability of saw dust and neem bark as low-cost natural adsorbents were investigated for adsorptive removal of Zn(II) and Cd(II) ions from aqueous solutions. Various physico-chemical parameters such as pH, initial metal ion concentration, and adsorbent dosage level and equilibrium contact time were studied. The optimum pH for adsorption was found to be 5 for Zn(II) and 6 for Cd(II). Kinetics data were best described by pseudo-second-order model. Mass transfer coefficients were also determined for individual adsorbents for removal of Zn(II) and Cd(II) ions from aqueous solutions. The equilibrium adsorption data were fitted to Langmuir and Freundlich isotherm models …

Electrical, Structural, And Chemical Properties Of Semiconducting Metal Oxide Nanofiber Yarns, Darrell Reneker

Darrell Hyson Reneker

The electrical, structural, and chemical properties of twisted yarns of metal-oxide nanofibers, fabricated using a modified electrospinning technique, are investigated in this report. In particular, synthesized zinc oxide and nickel oxide yarns having diameters in the range of 4–40μm and lengths up to 10cm were characterized, whose constituent nanofibers had average diameters of 60–100nm. These yarns have one macroscopic dimension for handling while retaining some of the properties of nanofibers.

The Direct Patterning Of Nanoporous Interlayer Dielectric Insulator Films By Nanoimprint Lithography, Alamgir Karim

Alamgir Karim

No abstract provided.

Does Faculty Research Improve Undergraduate Teaching: An Analysis Of Existing And Potential Synergies, Michael Prince, R. Felder, R. Brent

Michael J. Prince

No abstract provided.

Simulations Of Bubble Column Reactors Using A Volume Of Fluid Approach: Effect Of Air Distributor, Abid Akhtar

Abid Akhtar Mr

Two- and three-dimensional numerical simulations have been performed on a laboratory scale bubble column reactor using a volume-of-fluid approach. The effect of hole-size and superficial gas velocity on the bubble size distribution and their trajectories has been investigated on a 20 cm diameter and 1 m high cylindrical reactor. All simulations were performed in a transient manner using a FLUENT solver. Surface tension between two phases has been modelled as a body force with a constant value. Turbulence was modelled using the k-(epsilon) turbulence approach. A comparison between simulation predictions and the reported experimental studies has shown a good agreement.

The Influence Of Amino Acid Sequence And Functionality On The Binding Process Of Peptides Onto Gold Surfaces, Gustavo Carri

Gustavo A. Carri

We present a molecular dynamics study of the binding process of peptide A3 (AYSSGAPPMPPF) and other similar peptides onto gold surfaces, and identify the functions of many amino acids. Our results provide a clear picture of the separate regimes present in the binding process: diffusion, anchoring, crawling and binding. Moreover, we explored the roles of individual residues. We found that tyrosine, methionine, and phenylalanine are strong binding residues; serine serves as an effective anchoring residue; proline acts as a dynamic anchoring point, while glycine and alanine give flexibility to the peptide backbone. We then show that our findings apply to …

The Many Faces Of Inductive Teaching And Learning, Michael Prince, R. Felder

Michael J. Prince

No abstract provided.

Porous Fiber Formation In A Polymer-Solvent System Undergoing Solvent Evaporation, Thein Kyu

Thein Kyu

Temporal evolution of the fiber morphology during dry spinning has been investigated in the framework of Cahn-Hilliard equation [J. Chem. Phys.28, 258 (1958)] pertaining to the concentration order parameter or volume fraction given by the Flory-Huggins free energy of mixing [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, NY, 1953), p. 672] in conjunction with the solventevaporation rate. To guide the solventevaporation induced phase separation, equilibrium phase diagram of the starting polymer solution was established on the basis of the Flory-Huggins free energy of mixing. The quasi-steady-state approximation has been adopted to account for the nonconserved nature …

Inductive Teaching And Learning Methods: Definitions, Comparisons, And Research Bases, Michael Prince, R. Felder

Michael J. Prince

No abstract provided.

Branching In Electrospinning Of Nanofibers, Darrell Reneker

Darrell Hyson Reneker

Electrospinning of polymer nanofibers often begins with a single, straight, elongating, and electrified fluid jet that emanates from a droplet tip when the electric field at the surface is high enough. After some distance an electrically driven bending instability of the elongating jet occurs. For a polymer solution suitable for electrospinning, capillary instability does not cause the jet to become a spray of droplets. Under some conditions, a sequence of secondary jet branches emanates from the primary jet. This paper describes an experiment in which many closely spaced branches along the jet were observed during the electrospinning of a polycaprolactone …

Correlation Of Free Radical Copolymerization Behavior And Copolymer Properties With The Strength Of Pi-Pi Stacking Interactions Between Aromatic Fluorocarbons And Aromatic Hydrocarbons: Comparison Of The Copolymerization Behavior Of 2, 3, 4, 5, 6-Pentafluorostyrene With Styrene, 1-Vinylnaphthalene And 2-Vinylnaphthalene, Coleen Pugh

Coleen Pugh

No abstract provided.

Rupture Of Two-Dimensional Alkane Crystal, Ali Dhinojwala

Ali Dhinojwala

We have studied the breaking of a two-dimensional alkane crystal above the disordered melt using an oscillating bubble rheometer. Surface tension changes abruptly during the expansion and contraction cycle. We postulate that this is due to rupture of the 2D crystal at grain boundaries. The magnitude of the abrupt change in surface tension decreases with a decrease in the rate of change of bubble surface area with a power law exponent of 0.8. The interfacial area formed after rupture decreases with a decrease in rate. These results provide new insights in understanding defect-mediated rupture in confined geometry.

Template-Induced Enhanced Ordering Under Confinement, Mesfin Tsige

Mesfin Tsige

We report a surprisingly strong ordering of Si-(CH(3))(2) groups upon confinement between two surfaces, an oxidized poly(dimethyl siloxane) (PDMS(ox)) elastomer and a methyl-terminated self-assembled monolayer (octadecyltrichlorosilane (OTS)) on sapphire substrates. This enhanced ordering is induced by the template of ordered methyl groups of OTS and is not observed for other surfaces (fluorinated monolayers and sapphire substrates). This strong ordering is reminiscent of layering observed for confined symmetric molecules between two mica surfaces but was expected to vanish between rough macroscopic surfaces. These results provide new insights on confined structure at the interface between two solids and are important in the …