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Missouri University of Science and Technology

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2013

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Articles 1 - 30 of 156

Full-Text Articles in Engineering

Recent Development Of Surface Integral Equation Solvers For Multiscale Interconnects And Circuits, Sheng Sun, Lijun Jiang, Weng Cho Chew Dec 2013

Recent Development Of Surface Integral Equation Solvers For Multiscale Interconnects And Circuits, Sheng Sun, Lijun Jiang, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a brief review and recent development of surface integral equation solvers for multiscale interconnects and circuits modeling. As the future production processes down to 5 nm and the operating frequency increases, both multi-scale and large-scale natures should be taken into account in the electromagnetic simulations. Fast, efficient, stable, and broadband integral equation based solvers become indispensable when millions or ten s of millions of unknowns might be involved in the simulation of the integrated circuit. Recent progress and our latest researches in the development of broadband fast electromagnetic solvers will be demonstrated. © 2013 IEEE.

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Full-Quantum Simulation Of P-Type Junctionless Transistors With Multi-Band K · P Model, Jun Z. Huang, Weng Cho Chew, Li (Lijun) Jun Jiang, Jie Peng, Chi Yung Yam, Guan Hua Chen Dec 2013

Full-Quantum Simulation Of P-Type Junctionless Transistors With Multi-Band K · P Model, Jun Z. Huang, Weng Cho Chew, Li (Lijun) Jun Jiang, Jie Peng, Chi Yung Yam, Guan Hua Chen

Electrical and Computer Engineering Faculty Research & Creative Works

By adopting a model order reduction technique, we have successfully constructed a program for efficient simulation of nanowire transistors based on the multi-band k · p model and non-equilibrium Green's function (NEGF) approach. We then study for the first time the influences of various device parameters on the performances of p-type junctionless (JL) transistors and compare them to traditional inversion mode (IM) devices. © 2013 IEEE.

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An Efficiently Preconditioned Eigenanalysis Of Inhomogeneously Loaded Rectangular Cavities, Qi I. Dai, Yat Hei Lo, Weng Cho Chew, Li (Lijun) Jun Jiang Dec 2013

An Efficiently Preconditioned Eigenanalysis Of Inhomogeneously Loaded Rectangular Cavities, Qi I. Dai, Yat Hei Lo, Weng Cho Chew, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, we demonstrate an efficient preconditioning scheme for the eigenanalysis of inhomogeneously loaded rectangular cavities. Modeling the entire structure with the finite-difference frequency-domain (FDFD) method yields a large sparse eigenvalue problem. The desired interior eigen-spectrum is sought for by Arnoldi iterations with the shift-and-invert operation, where the inversion can only be performed iteratively in large-scale applications. A preconditioner is constructed to speed up the inversion. It can effectively shrink the spectrum of the governing matrix and can be solved for by using fast discrete sine and cosine transforms (DSTs and DCTs). Several numerical examples are included to illustrate …

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Fast And Efficient Low-Frequency Algorithms For Multiscale Structure Modeling, Sheng Sun, Zu Hui Ma, Qin S. Liu, Zhi Guo Qian, Lijun Jiang, Weng Cho Chew Dec 2013

Fast And Efficient Low-Frequency Algorithms For Multiscale Structure Modeling, Sheng Sun, Zu Hui Ma, Qin S. Liu, Zhi Guo Qian, Lijun Jiang, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reviews our recently developed fast and efficient algorithms for multiscale structure modeling. Low-frequency electromagnetic analysis becomes indispensable for multi-scale structures because of the involved minute length-scale compared to wavelength and mid length-scale on the order of wavelength or larger, where wave physics meets circuit physics. We are currently investigating stable low-frequency solutions in solving integral equations without the need for loop-tree decomposition, including the augmented EFIE, equivalence principle based algorithms, and perturbation-based Calderon multiplicative preconditioning methods. © 2013 IEEE.

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A Novel Broadband Equivalent Source Reconstruction Method For Broadband Radiators, Ping Li, Li (Lijun) Jun Jiang, Jun Hu, Sheng Sun Dec 2013

A Novel Broadband Equivalent Source Reconstruction Method For Broadband Radiators, Ping Li, Li (Lijun) Jun Jiang, Jun Hu, Sheng Sun

Electrical and Computer Engineering Faculty Research & Creative Works

Traditional equivalent source reconstruction methods are only operating at a single frequency point each time. However, for wide band radiators, their computation cost of the source reconstruction increases linearly with the number of frequency points. In this paper, a wide-band equivalent source reconstruction method (WB-SRM) based on the Neville-type Stoer-Bulirsch (SB) algorithm is developed. Supported by the adaptive frequency sampling (AFS) scheme, the number of required sampling data is significantly reduced, which leads to much better computational efficiency. During the AFS process, three fitting models (FM) are considered: two are 'triangle rules', and another one is 'rhombus rule'. The combination …

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Passivization Of Em Peec Solutions In The Frequency And Time Domain, Albert E. Ruehli, Giulio Antonini, Lijun Jiang Dec 2013

Passivization Of Em Peec Solutions In The Frequency And Time Domain, Albert E. Ruehli, Giulio Antonini, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The stability issues for time domain integral equations is well known and it has been investigated for a long time. In this paper, we pursue an approach for the stabilization and even passivization of the electromagnetic solutions in the time and frequency domain using the PEEC circuit techniques. We aim to enhance the passivity by adding more passivization to the EM solution rather than using a post-processing technique which have to be used in the EM solver is not available. © 2013 IEEE.

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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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Smart Rocks And Wireless Communication System For Real-Time Monitoring And Mitigation Of Bridge Scour -- A Proof-Of-Concept Study, Genda Chen, David Pommerenke, Y. Rosa Zheng, Andriy V. Radchenko, Yan Tang, Brandon P. Schafer, Ying Huang, Z. L. Yang Dec 2013

Smart Rocks And Wireless Communication System For Real-Time Monitoring And Mitigation Of Bridge Scour -- A Proof-Of-Concept Study, Genda Chen, David Pommerenke, Y. Rosa Zheng, Andriy V. Radchenko, Yan Tang, Brandon P. Schafer, Ying Huang, Z. L. Yang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims to integrate commercial measurement and communication components into a scour monitoring system with magnets or electronics embedded in smart rocks, and evaluate and improve its performance in laboratory and field conditions for the movement of smart rocks. Properly-designed smart rocks were found to be automatically rolled into the very bottom of a scour hole and can give critical information about the maximum scour depth and effectiveness of rip-rap mitigation strategies. Four types of smart rock technologies were investigated in this proof-of-concept phase of study, including passive with embedded magnets, active with magneto-inductive communication, active with controllable magnet …

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Enhanced A-Efie With Calderón Multiplicative Preconditioner, Sheng Sun, Lijun Jiang, Weng Cho Chew Dec 2013

Enhanced A-Efie With Calderón Multiplicative Preconditioner, Sheng Sun, Lijun Jiang, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, a Calderón multiplicative preconditioner (CMP) is proposed for the augmented electric field integral equation (A-EFIE) to improve the convergence. To avoid the imbalance between the vector potential and the scalar potential in the traditional EFIE, A-EFIE considers both the charge and the current as unknowns. After implementing the appropriate frequency scaling and the enforcement of charge neutrality, its formulation is also stable in the low-frequency regime and applicable for large-scale and complex problems. Instead of using other preconditioners, Calderón preconditioning converts the first kind integral equations into the second kind, thus improving the spectrum of the original …

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A Compact Hf/Uhf Dual Band Rfid Tag Antenna, Zi Long Ma, Li (Lijun) Jun Jiang, Jingtian Xi, Terry Tao Ye Dec 2013

A Compact Hf/Uhf Dual Band Rfid Tag Antenna, Zi Long Ma, Li (Lijun) Jun Jiang, Jingtian Xi, Terry Tao Ye

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel dual band RFID (radio frequency identification) tag antenna. Two challenges are faced: the compact dimension and the impaired bandwidth due to the couplings between two band structures. A spiral coil is designed to handle the HF (13.56MHz) near field coupling, and a diagonal symmetric design consisting of two meander lines are placed inside the coil for UHF band (915MHz). This structure supports multiple resonance modes around 915MHz to broaden the working bandwidth under the large inductive circumstance from the HF coil. The proposed antenna is easy to adjust by both coarse tuning and fine tuning. …

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Modeling Radiated Emissions Through Shielding Boxes Based On The Tangential Electrical Field Samplings Over Openings, Ping Li, Li (Lijun) Jun Jiang Dec 2013

Modeling Radiated Emissions Through Shielding Boxes Based On The Tangential Electrical Field Samplings Over Openings, Ping Li, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The radiation from radiators such as PCBs inside an enclosed shielding box with ventilation slots is an important issue for electromagnetic compatibility or interference characterizations. In this paper, a two-step process is proposed based on the equivalence principle and the electric field integral equation method to complete the radiation prediction. The tangential electric fields over the slots on shielding boxes are first sampled to be the equivalent magnetic currents radiated from internal PCBs. In the second step, to avoid the computation of complex nonanalytical dyadic Green's functions when the field radiation is computed directly from the equivalent source, the surface …

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Energy Analysis Of A Student-Designed Solar House, Samantha Wermager, Stuart Werner Baur Dec 2013

Energy Analysis Of A Student-Designed Solar House, Samantha Wermager, Stuart Werner Baur

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the findings from an undergraduate research project concerning the energy efficiency, consumption, and generation of a 1000 ft2 (92.9 m2) solar house. The results were compared to a home of similar size and layout, built using traditional construction methods. The solar house was modeled after the Chameleon House: Missouri University of Science and Technology's 2013 entry in the U.S. Department of Energy Solar Decathlon. The efficiency of the design was analyzed using Energy-10 Version 1.8 software. For this comparison, a fictional American couple was created and a breakdown of their energy-use habits was recorded …

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Three Dimensional Polarization Controllable Electromagnetic Cell, Bo Zhu, Weng Cho Chew, Lijun Jiang Dec 2013

Three Dimensional Polarization Controllable Electromagnetic Cell, Bo Zhu, Weng Cho Chew, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

We demonstrate an electromagnetic (EM) cell that can generate uniform electric field with three dimensional (3D) polarization dynamic control for the EM compatibility/interference (EMC/EMI) testing. 3D orthogonal slotline structures are designed and utilized to build the walls of the EM cell. By feeding the slotlines in phase and terminating them with matching loads, the uniform electric field similar to a standing wave is produced by two slotline modes propagating in opposite directions inside the cell. Microwave switches are integrated into the slotlines so that we can choose the operating slotline dynamically and change its orientation in a 3D manner by …

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An Enhanced Mixed-Form Fast Multipole Algorithm Using Rotation Methods, Ling Ling Meng, Li (Lijun) Jun Jiang Dec 2013

An Enhanced Mixed-Form Fast Multipole Algorithm Using Rotation Methods, Ling Ling Meng, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the broadband accuracy of the mixed-form fast multipole algorithm (MF-FMA) is improved by applying rotation techniques. Two kinds of rotation methods are employed respectively. One is the coordinate system rotation technique. The other one is the pseudospectral projection based on fast Fourier transform (FFT). Either of them has certain advantages depending on the number of multipoles. Through rotation, translation matrices become very sparse, which enables us to save the storage as well as the CPU time. Hence, we can increase the number of multipoles in the low frequency regime to shift up the transition region of MF-FMA. …

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Co-Simulation Of Distributive And Lumped Systems Using The Discontinuous Galerkin Time Domain Finite Element Method, Ping Li, Li (Lijun) Jun Jiang Dec 2013

Co-Simulation Of Distributive And Lumped Systems Using The Discontinuous Galerkin Time Domain Finite Element Method, Ping Li, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The signal integrity and power integrity analysis of 3D integrated circuits or other EMC/EMI systems usually separate the lumped circuit modeling and the distributive system modeling. However, due to the high density of integration, it is not proper to separate them in the modeling process anymore. In this paper, a hybrid electromagnetics (EM)-circuit simulator is proposed for incorporating multiport lumped circuit networks through their admittance matrices into the discontinuous Galerkin time-domain finite element method (DGTDFEM). The admittance matrix in the Laplace-domain can be derived analytically or obtained from network parameters such as S-parameters in the frequency domain. To convert frequency …

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Reducing Computational Workload Of Electromagnetic Scattered Fields From Electrically Large Quadratic Surface At High Frequency, Yu Mao Wu, Weng Cho Chew, Li (Lijun) Jun Jiang Dec 2013

Reducing Computational Workload Of Electromagnetic Scattered Fields From Electrically Large Quadratic Surface At High Frequency, Yu Mao Wu, Weng Cho Chew, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

We use the numerical steepest descent path (NSDP) method to calculate the highly oscillatory physical optics (PO) scattered fields on electrically large quadratic surfaces. The resultant phase behaviors of PO integrands are elliptic and hyperbolic on parabolic and saddle quadratic patches, respectively. The proposed method relies on deforming the integration path of the PO integral into the NSDPs on the complex plane. Numerical results of the PO scattered fields on these smooth conducting quadratic surfaces illustrate that the proposed NSDP method gains high accuracy while the workload is frequency independent. © 2013 IEEE.

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One Dimensional Multiple Periodic Composite Right/Left Handed (Crlh) Structures, Zi Long Ma, Li (Lijun) Jun Jiang, Shulabh Gupta, Wei E.I. Sha Dec 2013

One Dimensional Multiple Periodic Composite Right/Left Handed (Crlh) Structures, Zi Long Ma, Li (Lijun) Jun Jiang, Shulabh Gupta, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

The wave-propagation characteristics in a one-dimensional multiple-periodic (MP) Composite right/left-handed (CRLH) structures is presented, where it is found that an increase in the number of unit cells in each supercell leads to new passbands and stopbands. To understand this phenomenon, the network parameters are employed for the theoretical analysis. Detailed dispersion characteristics and the relation between passbands and sub-periodicities are investigated using both analytical and full-wave results, and the reasons for their emergence is qualitatively discussed. Besides, its application to multi-band leaky-wave radiators is also suggested. © 2013 IEEE.

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Limitations On High-Frequency Permeability Of Magnetic Materials, Konstantin N. Rozanov, Marina Koledintseva Dec 2013

Limitations On High-Frequency Permeability Of Magnetic Materials, Konstantin N. Rozanov, Marina Koledintseva

Electrical and Computer Engineering Faculty Research & Creative Works

Engineering of magnetic composites with high microwave permeability is important for EMC/EMI and other applications. One of the challenging problems is to determine constraints on the achievable high-frequency permeability of magnetic composites. The objective of the present paper is to analyze the data available from the literature on the microwave permeability constraints and derive a generalized constraint condition. It is well known that in many practical occasions the actual magnetic frequency dispersion curves differ from the Lorentzian behavior. For these cases, an integral form of the constraint may be useful. Possible applications of the integral constraint are discussed for the …

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An Efficient Preconditioning Scheme For Eigenanalysis Of Inhomogeneously Loaded Rectangular Cavities, Qi I. Dai, Yat Hei Lo, Lijun Jiang, Weng Cho Chew Dec 2013

An Efficient Preconditioning Scheme For Eigenanalysis Of Inhomogeneously Loaded Rectangular Cavities, Qi I. Dai, Yat Hei Lo, Lijun Jiang, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

An efficient preconditioning scheme for the eigenanalysis of inhomogeneously loaded rectangular cavities is presented. Such structures are modeled with the finite-difference frequency-domain (FDFD) method, while the desired interior eigen-spectra are sought for by Arnoldi iterations with the shiftand-invert operation. In large scale problems, the inversion can only be performed iteratively. A preconditioner is constructed in order to accelerate the inversion. It can effectively shrink the spectrum of the governing matrix, and can be solved for by using fast discrete sine and cosine transforms (DST's and DCT's). The efficiency of this scheme is demonstrated by several numerical examples. © 2013 IEEE.

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Analysis Of The Permeability Spectra Of Spinel Ferrite Composites Using Mixing Rules, Takanori Tsutaoka, Teruhiro Kasagi, Kenichi Hatakeyama, Marina Koledintseva Dec 2013

Analysis Of The Permeability Spectra Of Spinel Ferrite Composites Using Mixing Rules, Takanori Tsutaoka, Teruhiro Kasagi, Kenichi Hatakeyama, Marina Koledintseva

Electrical and Computer Engineering Faculty Research & Creative Works

Magnetic permeability spectra of composite materials containing spinel ferrites (Ni-Zn or Mn-Zn types) have been studied using a permeability dispersion formula by the numerical analysis. The variation of d.c. permeability and the frequency dispersion parameters due to domain wall and gyromagnetic spin resonances with particle content were evaluated using two mixing rules, Coherent Model Approximation (CMA) and Maxwell-Garnet Approximation (MGA) assuming the isotropic particle shape. The variation of d.c. permeability with particle content for spinel ferrite composite can be predicted by the CMA and MGA using the permeability value of embedded ferrite. The dc susceptibility and resonance frequency of domain …

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A New Coulomb Gauge Based Electric Field Integral Equation Method, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Wei E.I. Sha, Yat Hei Lo Dec 2013

A New Coulomb Gauge Based Electric Field Integral Equation Method, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Wei E.I. Sha, Yat Hei Lo

Electrical and Computer Engineering Faculty Research & Creative Works

The electric field integral equation (EFIE) method is one of the most commonly-adopted computational electromagnetic methods. Its popularity stems from the efficient surface triangulation, excellent numerical precision, and the powerful capability of handling open and complex geometries. However, when the frequency tends to zero, the method-of-moment (MoM) solution of EFIE using the Rao-Wilton-Glisson (RWG) basis functions suffers from the low-frequency breakdown, where the contribution from the vector potential is extremely imbalanced with that from the scalar potential. As a result, the matrix representation of EFIE operator is highly ill-conditioned and cannot be inverted reliably and efficiently. © 2013 IEEE.

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Chipless Rfid Tags Based On Multiple Band-Rejected Planar Log-Periodic Antennas, Shulabh Gupta, Li (Lijun) Jun Jiang Dec 2013

Chipless Rfid Tags Based On Multiple Band-Rejected Planar Log-Periodic Antennas, Shulabh Gupta, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A passive chipless Radio-frequency identification (RFID) tag is proposed based on the tailorable band-rejection property of the log-periodic (LP) antennas. The proposed tag principle is successfully demonstrated using full-wave simulations, where the absence and presence of the band-rejection in VSWR and thus radiation gain, is shown to carry the bit information. Due to the large number of dipole radiators on the LP aperture, the proposed tag can easily support large number of codes, providing a potential solution for limited number of bits in conventional chipless tags. © 2013 IEEE.

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Mechanism Of Crumb Rubber Modifier Dissolution Into Asphalt Matrix And Its Effect On Final Physical Properties Of Crumb Rubber-Modified Binder, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab Dec 2013

Mechanism Of Crumb Rubber Modifier Dissolution Into Asphalt Matrix And Its Effect On Final Physical Properties Of Crumb Rubber-Modified Binder, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Modification of asphalt by crumb rubber modifier (CRM) is mostly done through exchange of components between asphalt and CRM. At 160⁰ C and 10 Hz, CRM absorbs aromatics of asphalt and swells; however, at 220⁰ C and 50 Hz, CRM dissolves into the asphalt; this process leads to the release of different components of CRM including carbon black, fillers, and polymeric and oily components. Depending on interaction conditions, CRM dissolution is performed differently, and therefore the state and role of the released components can be different. In this research different mechanisms of dissolution of one size of CRM in asphalt …

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Liquid Phase Stability Under An Extreme Temperature Gradient, Zhi Liang, Kiran Sasikumar, Pawel Keblinski Nov 2013

Liquid Phase Stability Under An Extreme Temperature Gradient, Zhi Liang, Kiran Sasikumar, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using Nonequilibrium Molecular Dynamics Simulations, We Subject Bulk Liquid to a Very High-Temperature Gradient and Observe a Stable Liquid Phase with a Local Temperature Well above the Boiling Point. Also, under This High-Temperature Gradient, the Vapor Phase Exhibits Condensation into a Liquid at a Temperature Higher Than the Saturation Temperature, Indicating that the Observed Liquid Stability is Not Caused by Nucleation Barrier Kinetics. We Show that, Assuming Local Thermal Equilibrium, the Phase Change Can Be Understood from the Thermodynamic Analysis. the Observed Elevation of the Boiling Point is Associated with the Interplay between the "Bulk" Driving Force for the Phase …

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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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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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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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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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A Coaxial Cable Fabry-Perot Interferometer For Sensing Applications, Jie Huang, Tao Wang, Lei Hua, Jun Fan, Hai Xiao, Ming Luo Nov 2013

A Coaxial Cable Fabry-Perot Interferometer For Sensing Applications, Jie Huang, Tao Wang, Lei Hua, Jun Fan, Hai Xiao, Ming Luo

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reports a novel coaxial cable Fabry-Perot interferometer for sensing applications. The sensor is fabricated by drilling two holes half-way into a coaxial cable. The device physics was described. The temperature and strain responses of the sensor were tested. The measurement error was calculated and analyzed.

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Simulation Of Electromagnetic Waves In The Magnetized Cold Plasma By A Dgfetd Method, Ping Li, Li (Lijun) Jun Jiang Oct 2013

Simulation Of Electromagnetic Waves In The Magnetized Cold Plasma By A Dgfetd Method, Ping Li, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The properties of electromagnetic waves propagating in magnetized plasma slabs and scattering from plasma coated spheres are investigated using the discontinuous Galerkin finite-element time-domain (DGFETD) method. The magnetized plasma is a kind of gyroelectric anisotropic dispersive medium. This anisotropy must be described by an electric permittivity tensor with both nonzero diagonal and off-diagonal elements. Instead of doing the convolution directly in the time domain, an auxiliary differential equations (ADE) method is employed to represent the constitutive relation. The algorithm is validated by studying the transmission characteristics via electron-composed plasma slabs and radar cross section (RCS) of plasma-coated spheres. All numerical …

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