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Articles 4951 - 4980 of 21795

Full-Text Articles in Engineering

Additive Manufacturing Of Transparent Fused Quartz, Junjie Luo, John M. Hostetler, Luke Gilbert, Jonathan T. Goldstein, Augustine M. Urbas, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel Apr 2018

Additive Manufacturing Of Transparent Fused Quartz, Junjie Luo, John M. Hostetler, Luke Gilbert, Jonathan T. Goldstein, Augustine M. Urbas, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper investigates a filament-fed process for additive manufacturing (AM) of fused quartz. Glasses such as fused quartz have significant scientific and engineering applications, which include optics, communications, electronics, and hermetic seals. AM has several attractive benefits such as increased design freedom, faster prototyping, and lower processing costs for small production volumes. However, current research into glass AM has focused primarily on nonoptical applications. Fused quartz is studied here because of its desirability for use in high-quality optics due to its high transmissivity and thermal stability. Fused quartz filaments are fed into a CO2 laser-generated molten region, smoothly depositing …

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Direct Metal Laser-Sintered Stainless Steel: Comparison Of Microstructure And Hardness Between Different Planes, M. Ghasri-Khouzani, H. Peng, R. Attardo, P. Ostiguy, J. Neidig, R. Billo, D. Hoelzle, M. R. Shankar Apr 2018

Direct Metal Laser-Sintered Stainless Steel: Comparison Of Microstructure And Hardness Between Different Planes, M. Ghasri-Khouzani, H. Peng, R. Attardo, P. Ostiguy, J. Neidig, R. Billo, D. Hoelzle, M. R. Shankar

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microstructural analysis and micro-hardness measurements were performed on different planes of 316L stainless steel fabricated by direct metal laser sintering (DMLS) technique. A fine cellular network was observed within the steel microstructure, where morphology of most cells changed from columnar on XZ-plane (vertical section) to equiaxed on XY-plane (horizontal section). Correspondingly, morphology of most grains was found to alter from columnar for the XZ-plane to equiaxed in the case of the XY-plane. Moreover, X-ray diffraction (XRD) analysis revealed a fully austenitic structure for both the planes. The average micro-hardness value for the XZ-plane and XY-plane was insignificantly (≈ 3%) different, …

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Effects Of The Tempering And High-Pressure Torsion Temperatures Onmicrostructure Of Ferritic/Martensitic Steel Grade 91, Artur Ganeev, Marina Nikitina, Vil Sitdikov, Rinat Islamgaliev, Andrew Hoffman, Haiming Wen Apr 2018

Effects Of The Tempering And High-Pressure Torsion Temperatures Onmicrostructure Of Ferritic/Martensitic Steel Grade 91, Artur Ganeev, Marina Nikitina, Vil Sitdikov, Rinat Islamgaliev, Andrew Hoffman, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Grade 91 (9Cr-1Mo) steel was subjected to various heat treatments and then to high-pressure torsion (HPT) at different temperatures. Its microstructure was studied using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Effects of the tempering temperature and the HPT temperature on the microstructural features and microhardness in the ultrafine-grained (UFG) Grade 91 steel were researched. The study of the UFG structure formation takes into account two different microstructures observed: before HPT in both samples containing martensite and in fully ferritic samples.

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Equivalent Capacitance Approach To Calculate Effective Roughness Dielectric Parameters For Copper Foils On Printed Circuit Boards, Marina Y. Koledintseva, Tracey Vincent Apr 2018

Equivalent Capacitance Approach To Calculate Effective Roughness Dielectric Parameters For Copper Foils On Printed Circuit Boards, Marina Y. Koledintseva, Tracey Vincent

Electrical and Computer Engineering Faculty Research & Creative Works

Effective roughness dielectric (ERD) is a homogeneous lossy dielectric layer of certain thickness with effective (averaged) dielectric parameters. The ERD layer is used to model copper foil roughness in printed circuit board interconnects by being placed on a smooth conductor surface to substitute an inhomogeneous transition layer between a conductor and laminate substrate dielectric. This work derives the ERD parameters based on the understanding that there is a gradual variation of concentration of metallic inclusions in the transition layer between the dielectric and foil. The gradual variation can be structured as thin layers that are obtained using the equivalent capacitance …

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An Embeddable Strain Sensor With 30 Nano-Strain Resolution Based On Optical Interferometry, Chen Zhu, Yizheng Chen, Yiyang Zhuang, Fujian Tang, Jie Huang Apr 2018

An Embeddable Strain Sensor With 30 Nano-Strain Resolution Based On Optical Interferometry, Chen Zhu, Yizheng Chen, Yiyang Zhuang, Fujian Tang, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

A cost-effective, robust and embeddable optical interferometric strain sensor with nanoscale strain resolution is presented in this paper. The sensor consists of an optical fiber, a quartz rod with one end coated with a thin gold layer, and two metal shells employed to transfer the strain and orient and protect the optical fiber and the quartz rod. The optical fiber endface, combining with the gold-coated surface, forms an extrinsic Fabry—Perot interferometer. The sensor was firstly calibrated, and the result showed that our prototype sensor could provide a measurement resolution of 30 nano-strain (nε) and a sensitivity of 10.01 µε/ µm …

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Displacement And Strain Measurement Up To 1000 °C Using A Hollow Coaxial Cable Fabry-Perot Resonator, Chen Zhu, Yizheng Chen, Yiyang Zhuang, Jie Huang Apr 2018

Displacement And Strain Measurement Up To 1000 °C Using A Hollow Coaxial Cable Fabry-Perot Resonator, Chen Zhu, Yizheng Chen, Yiyang Zhuang, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

We present a hollow coaxial cable Fabry-Perot resonator for displacement and strain measurement up to 1000 °C. By employing a novel homemade hollow coaxial cable made of stainless steel as a sensing platform, the high-temperature tolerance of the sensor is dramatically improved. A Fabry-Perot resonator is implemented on this hollow coaxial cable by introducing two highly-reflective reflectors along the cable. Based on a nested structure design, the external displacement and strain can be directly correlated to the cavity length of the resonator. By tracking the shift of the amplitude reflection spectrum of the microwave resonator, the applied displacement and strain …

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Direct Error Driven Learning For Deep Neural Networks With Applications To Bigdata, R. Krishnan, Jagannathan Sarangapani, V. A. Samaranayake Apr 2018

Direct Error Driven Learning For Deep Neural Networks With Applications To Bigdata, R. Krishnan, Jagannathan Sarangapani, V. A. Samaranayake

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, generalization error for traditional learning regimes-based classification is demonstrated to increase in the presence of bigdata challenges such as noise and heterogeneity. To reduce this error while mitigating vanishing gradients, a deep neural network (NN)-based framework with a direct error-driven learning scheme is proposed. To reduce the impact of heterogeneity, an overall cost comprised of the learning error and approximate generalization error is defined where two NNs are utilized to estimate the costs respectively. To mitigate the issue of vanishing gradients, a direct error-driven learning regime is proposed where the error is directly utilized for learning. It …

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A Multi-Step Nonlinear Dimension-Reduction Approach With Applications To Bigdata, R. Krishnan, V. A. Samaranayake, Jagannathan Sarangapani Apr 2018

A Multi-Step Nonlinear Dimension-Reduction Approach With Applications To Bigdata, R. Krishnan, V. A. Samaranayake, Jagannathan Sarangapani

Mathematics and Statistics Faculty Research & Creative Works

In this paper, a multi-step dimension-reduction approach is proposed for addressing nonlinear relationships within attributes. In this work, the attributes in the data are first organized into groups. In each group, the dimensions are reduced via a parametric mapping that takes into account nonlinear relationships. Mapping parameters are estimated using a low rank singular value decomposition (SVD) of distance covariance. Subsequently, the attributes are reorganized into groups based on the magnitude of their respective singular values. The group-wise organization and the subsequent reduction process is performed for multiple steps until a singular value-based user-defined criterion is satisfied. Simulation analysis is …

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A Hollow Coaxial Cable Fabry-Perot Resonator For Liquid Dielectric Constant Measurement, Chen Zhu, Yiyang Zhuang, Yizheng Chen, Jie Huang Apr 2018

A Hollow Coaxial Cable Fabry-Perot Resonator For Liquid Dielectric Constant Measurement, Chen Zhu, Yiyang Zhuang, Yizheng Chen, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

We report, for the first time, a low-cost and robust homemade hollow coaxial cable Fabry-Pérot resonator (HCC-FPR) for measuring liquid dielectric constant. In the HCC design, the traditional dielectric insulating layer is replaced by air. A metal disk is welded onto the end of the HCC serving as a highly reflective reflector, and an open cavity is engineered on the HCC. After the open cavity is filled with the liquid analyte (e.g., water), the air-liquid interface acts as a highly reflective reflector due to large impedance mismatch. As a result, an HCC-FPR is formed by the two highly reflective reflectors, …

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A Novel Deep Junction Edge Termination For Superjunction Mosfets, Chia Hui Cheng, Chih Fang Huang, Kung Yen Lee, Feng Zhao Apr 2018

A Novel Deep Junction Edge Termination For Superjunction Mosfets, Chia Hui Cheng, Chih Fang Huang, Kung Yen Lee, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, a novel edge termination named deep junction termination for silicon super junction (SJ) MOSFETs is proposed, simulated, and experimentally demonstrated for the first time. By utilizing a typical implantation-and-epitaxy process to form P- and N-pillars for SJ, it is possible to form deep junctions as the device termination with a large radius of curvature and lateral and vertical doping gradation. The 2-D simulation shows that more than 700-V blocking voltage (BV) can be achieved by a 57-drift layer with this novel termination, and experimentally BV as high as 660 V is demonstrated by the fabricated device.

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High Voltage Gain Dc/Dc Power Electronic Converters, Mehdi Ferdowsi, Venkata Anand Kishore Prabhala Mar 2018

High Voltage Gain Dc/Dc Power Electronic Converters, Mehdi Ferdowsi, Venkata Anand Kishore Prabhala

Electrical and Computer Engineering Faculty Research & Creative Works

A DC/DC power converter provides high voltage gain using integrated boost and voltage multiplier (VM) stages. The boost cell operates according to a switching sequence to alternately energize and discharge a primary winding. A VM cell electrically coupled to the primary winding of the boost cell charges a multiplier capacitor to a DC output voltage greater than the input voltage when the primary winding is energized and discharges the multiplier capacitor when primary winding is discharged.

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Systems And Methods For Endotoxin Removal From Fluids, Sutapa Barua Mar 2018

Systems And Methods For Endotoxin Removal From Fluids, Sutapa Barua

Chemical and Biochemical Engineering Faculty Research & Creative Works

Systems and methods are provided for the removal of endotoxins from fluids. The methods can include the use of polymeric nanoparticles for binding endotoxins present in a fluid. The polymeric nanoparticles can be associated with a support member. The polymeric nanoparticles can have an endotoxin removal capacity of at least 1×109 endotoxin units per gram of polymeric nanoparticle (EU/g) and/or a removal efficacy per unit surface area of the polymeric nanoparticles of at least 1×106 EU/cm2.

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Complete Stress-Induced Depolarization Of Relaxor Ferroelectric Crystals Without Transition Through A Non-Polar Phase, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Wesley Hackenberger, Jun Luo, Shujun Zhang, Christopher S. Lynch, Jay B. Chase, Hwan R. Jo, Christopher C. Roberts Mar 2018

Complete Stress-Induced Depolarization Of Relaxor Ferroelectric Crystals Without Transition Through A Non-Polar Phase, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Wesley Hackenberger, Jun Luo, Shujun Zhang, Christopher S. Lynch, Jay B. Chase, Hwan R. Jo, Christopher C. Roberts

Mining Engineering Faculty Research & Creative Works

The development of relaxer ferroelectric single crystal technology is driven by the ability to tailor ferroelectric properties through domain engineering not achievable in polycrystalline materials. In this study, three types of domain-engineered rhombohedral Pb (In1/2Nb1/2) O3-Pb (Mg1/3Nb2/3) O3-PbTiO3 crystals were subjected to transverse high strain rate loading. The experimental results indicate that the domain configuration has a significant effect on the stress-induced depolarization and the associated charge released. A complete depolarization of the single-domain crystals with 3m symmetry is observed, while multidomain crystals with 4mm and mm2 …

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Microwave Materials Characterization And Imaging For Structural Health Monitoring, Reza Zoughi Mar 2018

Microwave Materials Characterization And Imaging For Structural Health Monitoring, Reza Zoughi

INSPIRE Archived Webinars

The relatively small wavelengths and large bandwidths associated with microwave signals make them great candidates for inspection of construction materials and structures, and for materials characterization and imaging. Signals at these frequencies readily penetrate inside of dielectric materials and composites and interact with their materials characteristics and inner structures. Water molecule is dipolar and possesses a relatively large complex dielectric constant, which is also highly sensitive to the presence of ions that increase its electrical conductivity. Consequently, chemical and physical changes in construction materials affect their complex dielectric constant. This can be measured, and through analytical and empirical dielectric mixing …

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Electrically Tunable Polarizer Based On Graphene-Loaded Plasmonic Cross Antenna, Yuwei Qin, Xiaoyan Y.Z. Xiong, Wei E.I. Sha, Li (Lijun) Jun Jiang Mar 2018

Electrically Tunable Polarizer Based On Graphene-Loaded Plasmonic Cross Antenna, Yuwei Qin, Xiaoyan Y.Z. Xiong, Wei E.I. Sha, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The unique gate-voltage dependent optical properties of graphene make it a promising electrically tunable plasmonic material. In this work, we proposed in situ control of the polarization of nanoantennas by combining plasmonic structures with an electrostatically tunable graphene monolayer. The tunable polarizer is designed based on an asymmetric cross nanoantenna comprising two orthogonal metallic dipoles sharing the same feed gap. Graphene monolayer is deposited on a Si/SiO2 substrate and inserted beneath the nanoantenna. Our modelling demonstrates that as the chemical potential is incremented up to 1 eV by electrostatic doping, resonant wavelength for the longer graphene-loaded dipole is blue shifted …

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Classical Molecular Dynamics Study For Defect Sink Behavior In Oxide Dispersed Strengthened Alloys, M. Mustafa Azeem, Zhongyu Li, Qingyu Wang, Qazi Muhammad Nouman Amjad, Muhammad Zubair, O. M.H. Ahmed Mar 2018

Classical Molecular Dynamics Study For Defect Sink Behavior In Oxide Dispersed Strengthened Alloys, M. Mustafa Azeem, Zhongyu Li, Qingyu Wang, Qazi Muhammad Nouman Amjad, Muhammad Zubair, O. M.H. Ahmed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Oxide Dispersed Strengthened (ODS) alloys are considered as a potential candidate for future generation reactors and can even be graded as better radiation resistant materials than the ones already in use. Molecular dynamics (MD) simulation study for defect sinks properties of ODS alloys have been investigated at 700K using LAMMPS (Atomic/Molecular massively parallel simulator software. SRIM (stopping range of ions in matter) code was used to see the approximate range of the ions and damage cascade profile. It has been observed that the oxide particle attracts vacancies/interstitials produced in the base matrix near the interface. The modeled structure looked amorphous …

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Orbital Angular Momentum Generation And Detection By Geometric-Phase Based Metasurfaces, Menglin L.N. Chen, Li (Lijun) Jun Jiang, Wei E.I. Sha Mar 2018

Orbital Angular Momentum Generation And Detection By Geometric-Phase Based Metasurfaces, Menglin L.N. Chen, Li (Lijun) Jun Jiang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

We present a comprehensive review on the geometric phase based metasurfaces for orbital angular momentum (OAM) generation and detection. Thesemetasurfacesmanipulate the electromagnetic (EM) wave by introducing abrupt phase change, which is strongly dependent on the polarization state of incident EMwave and can be interpreted by geometric phase. Hence, the conventional bulk devices that based on the accumulated phase change along the optical path can be avoided.

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Test Standard For Determining The Flexural Strength And Stiffness Of Cold-Formed Steel Nonstructural Members, 2017 Edition, American Iron And Steel Institute Mar 2018

Test Standard For Determining The Flexural Strength And Stiffness Of Cold-Formed Steel Nonstructural Members, 2017 Edition, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

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Dermal Uptake Of Nicotine From Air And Clothing: Experimental Verification, G. Bekö, Glenn Morrison, C. J. Weschler, H. M. Koch, C. Pälmke, T. Salthammer, T. Schripp, A. Eftekhari, J. Toftum, G. Clausen Mar 2018

Dermal Uptake Of Nicotine From Air And Clothing: Experimental Verification, G. Bekö, Glenn Morrison, C. J. Weschler, H. M. Koch, C. Pälmke, T. Salthammer, T. Schripp, A. Eftekhari, J. Toftum, G. Clausen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims to elucidate in greater detail the dermal uptake of nicotine from air or from nicotine-exposed clothes, which was demonstrated recently in a preliminary study. Six non-smoking participants were exposed to gaseous nicotine (between 236 and 304 μg/m3) over 5 hours while breathing clean air through a hood. Four of the participants wore only shorts and 2 wore a set of clean clothes. One week later, 2 of the bare-skinned participants were again exposed in the chamber, but they showered immediately after exposure instead of the following morning. The 2 participants who wore clean clothes on week 1 …

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Understanding Homogeneous Nucleation In Solidification Of Aluminum By Molecular Dynamics Simulations, A. Mahata, Mohsen Asle Zaeem, M. I. Baskes Mar 2018

Understanding Homogeneous Nucleation In Solidification Of Aluminum By Molecular Dynamics Simulations, A. Mahata, Mohsen Asle Zaeem, M. I. Baskes

Materials Science and Engineering Faculty Research & Creative Works

Homogeneous nucleation from aluminum (Al) melt was investigated by million-atom molecular dynamics simulations utilizing the second nearest neighbor modified embedded atom method potentials. The natural spontaneous homogenous nucleation from the Al melt was produced without any influence of pressure, free surface effects and impurities. Initially isothermal crystal nucleation from undercooled melt was studied at different constant temperatures, and later superheated Al melt was quenched with different cooling rates. The crystal structure of nuclei, critical nucleus size, critical temperature for homogenous nucleation, induction time, and nucleation rate were determined. The quenching simulations clearly revealed three temperature regimes: sub-critical nucleation, super-critical nucleation, …

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A New Wiretap Channel Model And Its Strong Secrecy Capacity, Mohamed Nafea, Aylin Yener Mar 2018

A New Wiretap Channel Model And Its Strong Secrecy Capacity, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a new wiretap channel model is proposed, where the legitimate transmitter and receiver communicate over a discrete memoryless channel. The wiretapper has perfect access to a fixed-length subset of the transmitted code word symbols of her choosing. Additionally, she observes the remainder of the transmitted symbols through a discrete memoryless channel. This new model subsumes the classical wiretap channel and wiretap channel II with noisy main channel as its special cases and is termed as the generalized wiretap channel for that reason. The strong secrecy capacity of the proposed channel model is identified. Achievability is established by …

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Injectable Glass Polyalkenoate Cements: Evaluation Of Their Rheological And Mechanical Properties With And Without The Incorporation Of Lidocaine Hydrochloride, P. Niranjan, A. Alhalawani, S. Phull, I. Beniluz, B. Krishnan, P. Zalzal, Mark R. Towler Mar 2018

Injectable Glass Polyalkenoate Cements: Evaluation Of Their Rheological And Mechanical Properties With And Without The Incorporation Of Lidocaine Hydrochloride, P. Niranjan, A. Alhalawani, S. Phull, I. Beniluz, B. Krishnan, P. Zalzal, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Lidocaine hydrochloride is used as an anesthetic in many clinical applications. This short communication investigates the effect of complete substitution of lidocaine hydrochloride for deionized (DI) water on the physico-chemical properties of two novel glass polyalkenoate cements. Substituting DI water with lidocaine hydrochloride resulted in cements with shorter working times but comparable setting times and mechanical properties. Fourier transform infrared spectroscopy confirmed that the setting reaction in cements containing DI water and lidocaine hydrochloride was completed within 24 h, post cement preparation and maturation. Further, it was explained that lidocaine hydrochloride binds to poly(acrylic) acid (PAA) due to electrostatic forces …

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The Effect Of Mg²⁺ Incorporation Into The Glass Phase Of Zinc-Based Glass Polyalkenoate Cements, Basel A. Khader, Omar Rodriguez, Mark R. Towler Mar 2018

The Effect Of Mg²⁺ Incorporation Into The Glass Phase Of Zinc-Based Glass Polyalkenoate Cements, Basel A. Khader, Omar Rodriguez, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of glass polyalkenoate cements (GPCs) as injectable adhesives in orthopedics have been compromised by the presence of aluminum (Al), a component in the glass phase of all commercial GPCs. There has been considerable work on the development of Al-free GPCs which can be formulated based on calcium (Ca) zinc (Zn) silicate (Si) glasses. These materials, in terms of biocompatibility and mechanical properties, have potential for orthopedics. However, many of these experimental Al-free GPCs have setting times shorter than 60 s, restricting clinical applications. Here, the authors incorporate Magnesium (Mg) into the glass phase of Al-free GPCs in an …

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Twisting Phase And Intensity Of Light With Plasmonic Metasurfaces, Yuchao Zhang, Xiaodong Yang, Jie Gao Mar 2018

Twisting Phase And Intensity Of Light With Plasmonic Metasurfaces, Yuchao Zhang, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Twisting light in both phase and intensity has recently drawn great interests in various fields related to light-matter interactions such as optical manipulation of particles and quantum entanglement of photons. Conventionally, bulky optical components are required to produce such twisted optical beams, which significantly limits their applications in integrated photonics and optical chips. Here, we design and demonstrate aluminum plasmonic metasurfaces consisting of nanoslit antennas as ultracompact beam converters to generate the focused twisted beams in both phase and intensity across the visible wavelength range. The metasurface is encoded with the combined phase profile containing the helico-conical phase function together …

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Ultra-Broadband Infrared Absorption By Tapered Hyperbolic Multilayer Waveguides, Huixu Deng, Cherian J. Mathai, Shubhra Gangopadhyay, Jie Gao, Xiaodong Yang Mar 2018

Ultra-Broadband Infrared Absorption By Tapered Hyperbolic Multilayer Waveguides, Huixu Deng, Cherian J. Mathai, Shubhra Gangopadhyay, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ultra-broadband strong absorption over 92% covering the infrared wavelength range of 1 ~ 6μm is demonstrated by using the tapered hyperbolic Au-SiO2 multilayer waveguides on glass substrates. Such broadband absorption is formed by the stop-light modes at various wavelengths located at different waveguide widths. A planar hyperbolic waveguide model is built to determine the stop-light modes by considering both forward and backward guided modes. The stop-light modes located inside the Au-SiO2 multilayer waveguide are simulated at the absorption peaks by reducing the Au loss. Tapered multilayer waveguides with varying top widths are further simulated, fabricated and measured, indicating …

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Wavelength-Selective Mid-Infrared Metamaterial Absorbers With Multiple Tungsten Cross Resonators, Zhigang Li, Liliana Stan, David A. Czaplewski, Xiaodong Yang, Jie Gao Mar 2018

Wavelength-Selective Mid-Infrared Metamaterial Absorbers With Multiple Tungsten Cross Resonators, Zhigang Li, Liliana Stan, David A. Czaplewski, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Wavelength-selective metamaterial absorbers in the mid-infrared range are demonstrated by using multiple tungsten cross resonators. By adjusting the geometrical parameters of cross resonators in single-sized unit cells, near-perfect absorption with single absorption peak tunable from 3.5 µm to 5.5 µm is realized. The combination of two, three, or four cross resonators of different sizes in one unit cell enables broadband near-perfect absorption at mid-infrared range. The obtained absorption spectra exhibit omnidirectionality and weak dependence on incident polarization. The underlying mechanism of near-perfect absorption with cross resonators is further explained by the optical mode analysis, dispersion relation and equivalent RLC circuit …

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Numerical Study Of Lateral Migration Of Elliptical Magnetic Microparticles In Microchannels In Uniform Magnetic Fields, Jie Zhang, Cheng Wang Mar 2018

Numerical Study Of Lateral Migration Of Elliptical Magnetic Microparticles In Microchannels In Uniform Magnetic Fields, Jie Zhang, Cheng Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This work reports numerical investigation of lateral migration of a paramagnetic microparticle of an elliptic shape in a plane Poiseuille flow of a Newtonian fluid under a uniform magnetic field by direct numerical simulation (DNS). A finite element method (FEM) based on the arbitrary Lagrangian–Eulerian (ALE) approach is used to study the effects of strength and direction of the magnetic field, particle–wall separation distance and particle shape on the lateral migration. The particle is shown to exhibit negligible lateral migration in the absence of a magnetic field. When the magnetic field is applied, the particle migrates laterally. The migration direction …

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A Continuum Model Of Mucosa With Glycan-Ion Pairing, James D. Sterling, Shenda M. Baker Mar 2018

A Continuum Model Of Mucosa With Glycan-Ion Pairing, James D. Sterling, Shenda M. Baker

Business and Information Technology Faculty Research & Creative Works

Advances in the study of glycosoaminoglycan biohydrogels, label-free electrokinetic analysis of soft-diffuse layers in contact with saline solutions, and elucidation of ion-specific behavior in many biochemical systems offer the opportunity to marry these principal features in a new mathematical model of the mucosal glycocalyx. The model is based on the electroquasistatic subset of Maxwell's equations in the form of the steady-state continuum Poisson–Boltzmann equation for electrostatics with explicit incorporation of pairwise binding of ions to fixed charged-groups in the hydrogel. The pairwise association is modeled using reversible bimolecular reactions via stoichiometric dissociation constants that represent the rule of matching water …

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The Effect Of Weak Confinement On The Orientation Of Nanorods Under Shear Flows, Saman Monjezi, James D. Jones, Alyssa K. Nelson, Joontaek Park Mar 2018

The Effect Of Weak Confinement On The Orientation Of Nanorods Under Shear Flows, Saman Monjezi, James D. Jones, Alyssa K. Nelson, Joontaek Park

Chemical and Biochemical Engineering Faculty Research & Creative Works

We performed a numerical analysis to study the orientation distribution of a dilute suspension of thin, rigid, rod-like nanoparticles under shearing flow near a solid boundary of weak confinement. Brownian dynamics simulation of a rod was performed under various ratios of shear rate and rod diffusivity (Peclet number), as well as the center-of-mass position (wall confinement). We discuss the effects of Peclet number and wall confinement on the angle distributions, Jeffery orbit distribution and average orientation moments. The average orientation moments, obtained as a function of Peclet number and wall confinement, can be used to improve a previous shear-induced migration …

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System, Devices And Methods For Molecular Separation, Sankar Nair, Christopher W. Jones, Fereshteh Rashidi, Ali A. Rownaghi Mar 2018

System, Devices And Methods For Molecular Separation, Sankar Nair, Christopher W. Jones, Fereshteh Rashidi, Ali A. Rownaghi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Systems, devices and methods for molecular separation including a molecular separation device comprising at least a polycrystalline metal-organic framework (MOF) and a nanocrystalline, zeolite MFI, wherein the MOF forms a polycrystalline membrane with zeolite MFI nanoparticles dispersed therein, and the MOF membrane matrix contacting and surrounding the zeolite MFI nanoparticles form a permselective nanoporous structure.

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