Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Optimal Control (41)
- Additive manufacturing (36)
- Neurocontrollers (30)
- Nonlinear Control Systems (28)
- Control System Synthesis (21)
-
- Adaptive Control (18)
- Feedback (13)
- Neural Nets (13)
- Neural Networks (11)
- Robots (11)
- Stability (11)
- 3D printers (10)
- Deposition (10)
- Laser metal deposition (10)
- Learning Systems (10)
- Solid Freeform Fabrication (10)
- Additive Manufacturing (9)
- Mechanical properties (9)
- Distributed Parameter Systems (8)
- Dynamic Programming (8)
- Extrusion (8)
- Learning (Artificial Intelligence) (8)
- Position Control (8)
- Riccati Equations (8)
- Aerospace Control (7)
- Closed Loop Systems (7)
- Fabrication (7)
- Microstructure (7)
- Rapid Prototyping (7)
- Directed energy deposition (6)
- Publication Year
- Publication
-
- Mechanical and Aerospace Engineering Faculty Research & Creative Works (770)
- UMR-MEC Conference on Energy / UMR-DNR Conference on Energy (59)
- Materials Science and Engineering Faculty Research & Creative Works (36)
- Opportunities for Undergraduate Research Experience Program (OURE) (28)
- Electrical and Computer Engineering Faculty Research & Creative Works (25)
-
- Chemistry Faculty Research & Creative Works (8)
- Biological Sciences Faculty Research & Creative Works (7)
- Civil, Architectural and Environmental Engineering Faculty Research & Creative Works (7)
- Chemical and Biochemical Engineering Faculty Research & Creative Works (6)
- Computer Science Faculty Research & Creative Works (6)
- Engineering Management and Systems Engineering Faculty Research & Creative Works (4)
- Mathematics and Statistics Faculty Research & Creative Works (4)
- Physics Faculty Research & Creative Works (4)
- Mining Engineering Faculty Research & Creative Works (3)
- Psychological Science Faculty Research & Creative Works (3)
- Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works (1)
- Honors Academy (1)
Articles 421 - 450 of 972
Full-Text Articles in Engineering
Numerical Analysis Of Thermal Stress And Deformation In Multi-Layer Laser Metal Deposition Processes, Heng Liu, Todd E. Sparks, Frank W. Liou, David M. Dietrich
Numerical Analysis Of Thermal Stress And Deformation In Multi-Layer Laser Metal Deposition Processes, Heng Liu, Todd E. Sparks, Frank W. Liou, David M. Dietrich
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Direct metal deposition (DMD) has gained increasing attention in the area of rapid manucooling rate, resulting in residual stresses and distortion. This paper presents a 3D sequentially coupled thermo-mechanical finite element model to predict residual stresses and deformations. The temperature distribution, thermal stress field and geometry deformation across domain are illustrated. The effect of deposition parameters on residual stress and deflections are also explored. A set of validation experiments for mechanical effects were conducted using laser displacement sensor. The comparisons between the simulated and experimental results show good agreement
Vision-Based Process Monitoring For Laser Metal Deposition Processes, Sreekar Karnati, Niroop Matta, Todd E. Sparks, Frank W. Liou
Vision-Based Process Monitoring For Laser Metal Deposition Processes, Sreekar Karnati, Niroop Matta, Todd E. Sparks, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Laser Metal deposition is a process with immense scope and promise for becoming a robust manufacturing technology in the near future. Monitoring process variables is very instrumental in process planning and output monitoring. The current work deals with realizing the effect of power modulation on size of the high temperature region during deposition with varying powder feed. A thermal camera was used to visualize and analyze the deposition process. The area of the high temperature region through the deposition was identified and compared to realize the effect of each variable parameter during deposition. The power modulation was fruitful in modulating …
Effect Of Architecture And Porosity On Mechanical Properties Of Borate Glass Scaffolds Made By Selective Laser Sintering, Krishna C. R. Kolan, Ming-Chuan Leu, Greg Hilmas, Taylor Comte
Effect Of Architecture And Porosity On Mechanical Properties Of Borate Glass Scaffolds Made By Selective Laser Sintering, Krishna C. R. Kolan, Ming-Chuan Leu, Greg Hilmas, Taylor Comte
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The porosity and architecture of bone scaffolds, intended for use in bone repair or replacement, are two of the most important parameters in the field of bone tissue engineering. The two parameters not only affect the mechanical properties of the scaffolds but also aid in determining the amount of bone regeneration after implantation. Scaffolds with five different architectures and four porosity levels were fabricated using borate bioactive glass (13-93B3) using the selective laser sintering (SLS) process. The pore size of the scaffolds varied from 400 to 1300 μm. The compressive strength of the scaffolds varied from 1.7 to 15.5 MPa …
Experimental Investigation Of Different Cellular Lattice Structures Manufactured By Fused Deposition Modeling, Osman Iyibilgin, Cemil Yigit, Ming-Chuan Leu
Experimental Investigation Of Different Cellular Lattice Structures Manufactured By Fused Deposition Modeling, Osman Iyibilgin, Cemil Yigit, Ming-Chuan Leu
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Experimental tests were conducted to evaluate the compressive properties (yield strength and compressive modulus) and build time for five different cellular lattice structures fabricated by the Fused Deposition Modeling (FDM) process. The lattice structures had repeating unit cells, and the shapes of the unit cell under study included honeycomb, square, diamond, triangle, and circle. Test specimens were manufactured by a Stratasys Fortus 400mc machine using ABS (Acrylonitrile Butadiene Styrene) as the part material. The five different lattice structures were compared with each other and also with the sparse and sparse-double dense build styles that are directly available from the Fortus …
Additive Manufacturing Laser Deposition Of Ti‐6al‐4v For Aerospace Repair Applications, Nanda Kumar Dey, Frank W. Liou, C. Nedic
Additive Manufacturing Laser Deposition Of Ti‐6al‐4v For Aerospace Repair Applications, Nanda Kumar Dey, Frank W. Liou, C. Nedic
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Parts or products from high performance metal are very expensive, partly due to the processing complexities during manufacturing. The purpose of this project is to use additive laser deposition and machining processes to repair titanium parts, thus extending the service life of these parts. The study broadly included preparing the defects, laser deposition, machining, sample preparation and mechanical tests. Comparative study of mechanical properties (UTS, YS, percentage elongation) of the repaired samples to the ideal conditions was undertaken. The research throws up interesting facts where the data from the test sample shows enhancement of properties of the repaired part.
Hybrid System For Enhancing Algal Growth Using Vertical Membranes, David J. Bayless, Ben J. Stuart
Hybrid System For Enhancing Algal Growth Using Vertical Membranes, David J. Bayless, Ben J. Stuart
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A method for enhancing gas-to-liquid transfer rate and algal growth using vertical membranes suspended over a pond, wherein the membranes are formed of fibers. An aqueous solution is applied to the top edges of the membranes through a series of headers. The membranes are exposed to a stream of gas containing soluble gas species as the aqueous solution migrates downwardly through the membranes by virtue of gravity-assisted capillary action. The aqueous solution collects the soluble gases from the gas stream, thus promoting the growth of photosynthetic organisms on the membranes and in the pond. The membranes facilitate a gradual introduction …
Near- And Far-Field Spectroscopic Imaging Investigation Of Resonant Square-Loop Infrared Metasurfaces, J. D'Achangel, E. Tucker, Edward C. Kinzel, E. A. Muller, H. A. Bechtel, M. B. Martin, G. Boreman
Near- And Far-Field Spectroscopic Imaging Investigation Of Resonant Square-Loop Infrared Metasurfaces, J. D'Achangel, E. Tucker, Edward C. Kinzel, E. A. Muller, H. A. Bechtel, M. B. Martin, G. Boreman
Mechanical and Aerospace Engineering Faculty Research & Creative Works
No abstract provided.
Apparatus And Method For Growing Biological Organisms For Fuel And Other Purposes, David J. Bayless, Morgan Lefay Vis-Chiasson, Ben J. Stuart, Gregory G. Kremer
Apparatus And Method For Growing Biological Organisms For Fuel And Other Purposes, David J. Bayless, Morgan Lefay Vis-Chiasson, Ben J. Stuart, Gregory G. Kremer
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A bioreactor apparatus in which a container has sidewalls, a floor and a ceiling defining a chamber that contains a slurry of water, nutrients and photosynthetic microorganisms. A plurality of optical fibers, each of which has a first end disposed outside the chamber and a second end in the mixture. A light collector spaced from the container has light incident on it and focuses the light onto the first ends of the plurality of optical fibers, thereby permitting the light to be conveyed into the mixture to promote photosynthesis. At least one nozzle is in fluid communication with a source …
Structural Health Monitoring Data Transmission For Composite Hydrokinetic Turbine Blades, A. Heckman, Joshua L. Rovey, K. Chandrashekhara, Steve Eugene Watkins, Daniel S. Stutts, Arindam Banerjee, Rajiv S. Mishra
Structural Health Monitoring Data Transmission For Composite Hydrokinetic Turbine Blades, A. Heckman, Joshua L. Rovey, K. Chandrashekhara, Steve Eugene Watkins, Daniel S. Stutts, Arindam Banerjee, Rajiv S. Mishra
Mechanical and Aerospace Engineering Faculty Research & Creative Works
No abstract provided.
Numerical Investigation Of Plasma Actuator Configurations For Flow Separation Control At Multiple Angles Of Attack, Thomas Kelsey Iv, West, Serhat Hosder
Numerical Investigation Of Plasma Actuator Configurations For Flow Separation Control At Multiple Angles Of Attack, Thomas Kelsey Iv, West, Serhat Hosder
Mechanical and Aerospace Engineering Faculty Research & Creative Works
No abstract provided.
Equilibrium And Nonequilibrium Molecular Dynamics Simulations Of Thermal Conductance At Solid-Gas Interfaces, Zhi Liang, William Evans, Pawel Keblinski
Equilibrium And Nonequilibrium Molecular Dynamics Simulations Of Thermal Conductance At Solid-Gas Interfaces, Zhi Liang, William Evans, Pawel Keblinski
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The Thermal Conductance at Solid-Gas Interfaces with Different Interfacial Bonding Strengths is Calculated through Green-Kubo Equilibrium Molecular Dynamics (EMD) Simulations. Due to the Finite Size of the Simulation System, the Long-Time Integral of the Time Correlation Function of Heat Power Across the Solid-Gas Interface Exhibits an Exponential Decay, Which Contains the Information on Interfacial Thermal Conductance. If an Adsorbed Gas Layer is Formed on the Solid Surface, It is Found that the Solid-Gas Interface Needs to Be Defined at a Plane Outside the Adsorbed Layer So as to Obtain the Correct Result from the Green-Kubo Formula. the EMD Simulation Result …
Improvement Of Heat Transfer Efficiency At Solid-Gas Interfaces By Self-Assembled Monolayers, Zhi Liang, William Evans, Tapan Desai, Pawel Keblinski
Improvement Of Heat Transfer Efficiency At Solid-Gas Interfaces By Self-Assembled Monolayers, Zhi Liang, William Evans, Tapan Desai, Pawel Keblinski
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Using Molecular Dynamics Simulations, We Demonstrate that the Efficiency of Heat Exchange between a Solid and a Gas Can Be Maximized by Functionalizing Solid Surface with Organic Self-Assembled Monolayers (SAMs). We Observe that for Bare Metal Surfaces, the Thermal Accommodation Coefficient (TAC) Strongly Depends on the Solid-Gas Interaction Strength. for Metal Surfaces Modified with Organic SAMs, the TAC is Close to its Theoretical Maximum and is Essentially Independent from the SAM-Gas Interaction Strength. the Analysis of the Simulation Results Indicates that Softer and Lighter SAMs, Compared to the Bare Metal Surfaces, Are Responsible for the Greatly Enhanced TAC. © 2013 …
Numerical Study Of Pressure Fluctuations Due To A Mach 6 Turbulent Boundary Layer, Lian Duan, Meelan M. Choudhari
Numerical Study Of Pressure Fluctuations Due To A Mach 6 Turbulent Boundary Layer, Lian Duan, Meelan M. Choudhari
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Direct numerical simulations (DNS) are used to examine the pressure fluctuations generated by a Mach 6 turbulent boundary layer with nominal freestream Mach number of 6 and Reynolds number of Reτ ≈ 464. The emphasis is on comparing the primarily vortical pressure signal at the wall with the acoustic freestream signal under higher Mach number conditions. Moreover, the Mach-number dependence of pressure signals is demonstrated by comparing the current results with those of a supersonic boundary layer at Mach 2.5 and Reτ ≈ 510. It is found that the freestream pressure intensity exhibits a strong Mach number dependence, irrespective of …
Loss Enhanced Transmission And Collimation In Anisotropic Epsilon-Near-Zero Metamaterials, L. Sun, S. Feng, Xiaodong Yang
Loss Enhanced Transmission And Collimation In Anisotropic Epsilon-Near-Zero Metamaterials, L. Sun, S. Feng, Xiaodong Yang
Mechanical and Aerospace Engineering Faculty Research & Creative Works
We verify the extraordinary transmission enhancement and collimation induced by the material loss in anisotropic epsilon-near-zero metamaterials, and reveal the physical mechanism of this exotic electromagnetic phenomenon via the iso-frequency contour analysis. In addition, we demonstrate the possibility in realization of such loss enhanced transmission of Gaussian beam in realistic silver-germanium multilayered structures by applying full-wave numerical simulations.
A Method To Generate Pressure Gradients For Molecular Simulation Of Pressure-Driven Flows In Nanochannels, Zhi Liang, Hai-Lung Tsai
A Method To Generate Pressure Gradients For Molecular Simulation Of Pressure-Driven Flows In Nanochannels, Zhi Liang, Hai-Lung Tsai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
One of the Difficulties in Molecular Simulation of Pressure-Driven Fluid Flow in Nanochannels is to Find an Appropriate Pressure Control Method. When Periodic Boundary Conditions (PBCs) Are Applied, a Gravity-Like Field Has Been Widely Used to Replace Actual Pressure Gradients. the Gravity-Fed Method is Not Only Artificial, But Not Adequate for Studying Properties of Fluid Systems Which Are Essentially Inhomogeneous in the Flow Direction. in This Paper, a Method is Proposed Which Can Generate Any Desired Pressure Difference to Drive the Fluid Flow by Attaching a "Pump" to the Nanofluidic System, While the Model is Still Compatible with PBCs. the …
Modeling, Analysis And Simulation Of Paste Freezing In Freeze-Form Extrusion Fabrication, Mingyang Li, Robert G. Landers, Ming-Chuan Leu
Modeling, Analysis And Simulation Of Paste Freezing In Freeze-Form Extrusion Fabrication, Mingyang Li, Robert G. Landers, Ming-Chuan Leu
Mechanical and Aerospace Engineering Faculty Research & Creative Works
During the freeze-form extrusion fabrication process for aqueous-based pastes, the sub-zero temperature environment aids the part in maintaining its shape by freezing the water present in the paste. The paste freezes very quickly when deposited on a substrate in a freezing environment. However, as the part’s height increases, the freezing time increases as the heat conduction rate to the substrate decreases. The freezing time can exceed the time required to extrude one layer of paste due to water’s high latent heat, thus leaving the extruded paste in its semi-liquid state and causing the part to deform or even collapse. Therefore, …
Comparison Of Compression Molding And Selective Laser Sintering Processes In The Development Of Composite Bipolar Plates For Proton Exchange Membrane Fuel Cells, Ehsan Taghipour, Ming-Chuan Leu, Nannan Guo
Comparison Of Compression Molding And Selective Laser Sintering Processes In The Development Of Composite Bipolar Plates For Proton Exchange Membrane Fuel Cells, Ehsan Taghipour, Ming-Chuan Leu, Nannan Guo
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Bipolar plates are key components of Proton Exchange Membrane (PEM) fuel cells. They carry current away from the cell and withstand the clamping force of the stack assembly. Therefore, PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical strength, in addition to being light weight and low cost in terms of both applicable materials and production methods. In order to attain these goals, we have manufactured graphite-carbon- polymer composite plates using Compression Molding (CM), which is suitable for mass production, and Selective Laser Sintering (SLS), which is suitable for making prototypes. In this paper, the electrical …
The Applications Of Additive Manufacturing Technologies In Cyber-Enabled Manufacturing Systems, Sriram Praneeth Isanaka, Frank W. Liou
The Applications Of Additive Manufacturing Technologies In Cyber-Enabled Manufacturing Systems, Sriram Praneeth Isanaka, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The application of networked sensors and control in various areas, such as smart grids and infrastructures, has become a recent trend, called cyber-physical systems. The Cyber Enabled Manufacturing (CEM) environment is to apply these technologies in manufacturing systems to handle a significantly greater magnitude of manufacturing data. Additive manufacturing techniques print or place material layer by layer to form a part, thus have a great potential to help accelerate CEM process by printing or embedding sensors and actuators in the proper locations. This paper summarizes the roles of additive manufacturing technologies to help establish a CEM environment.
Interactions Of An Additive Manufacturing Program With Society, Frank W. Liou, Ming-Chuan Leu, Robert G. Landers
Interactions Of An Additive Manufacturing Program With Society, Frank W. Liou, Ming-Chuan Leu, Robert G. Landers
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Additive Manufacturing (AM) has shown considerable promise for the future but also proposes some challenges. Many AM barriers tend to be non-technical and instead are human-centric issues such as lack of education of practitioners in AM capabilities, cultural differences, vested interests, and potentially lack of imagination. It is highly desirable for all research and educational institutions to help address these issues. This paper summarizes the additive manufacturing research and education program at the Missouri University of Science and Technology (Missouri S&T) and its interactions with various constituents, including K-12 students, undergraduate and graduate students, distance students, and industry.
Freeze-Form Extrusion Fabrication Of Functionally Graded Material Composites Using Zirconium Carbide And Tungsten, Ang Li, Aaron S. Thornton, Bradley K. Deuser, Jeremy Lee Watts, Ming-Chuan Leu, Greg Hilmas, Robert G. Landers
Freeze-Form Extrusion Fabrication Of Functionally Graded Material Composites Using Zirconium Carbide And Tungsten, Ang Li, Aaron S. Thornton, Bradley K. Deuser, Jeremy Lee Watts, Ming-Chuan Leu, Greg Hilmas, Robert G. Landers
Materials Science and Engineering Faculty Research & Creative Works
Ultra-high-temperature ceramics are being investigated for future use in aerospace applications due to their superior thermo-mechanical properties, as well as their oxidation resistance, at temperatures above 2000⁰C. However, their brittleness makes them susceptible to thermal shock failure. As graded composites, components fabricated as functionally-graded materials (FGMs) can combine the superior properties of ceramics with the toughness of an underlying refractory metal. This paper discusses the grading of two materials through the use of a Freeze-form Extrusion Fabrication (FEF) system to build FGM parts consisting of zirconium carbide (ZrC) and tungsten (W). Aqueous-based colloidal suspensions of ZrC and W were developed …
Experimental Study Of Polymer Electrolyte Membrane Fuel Cells Using A Graphite Composite Bipolar Plate Fabricated By Selective Laser Sintering, Nannan Guo, Ming-Chuan Leu
Experimental Study Of Polymer Electrolyte Membrane Fuel Cells Using A Graphite Composite Bipolar Plate Fabricated By Selective Laser Sintering, Nannan Guo, Ming-Chuan Leu
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Selective Laser Sintering (SLS) can be used to fabricate graphite composite bipolar plates with complex flow fields for Polymer Electrolyte Membrane (PEM) fuel cells. The additive manufacturing process can significantly reduce the time and cost associated with the research and development of bipolar plates as compared to other fabrication methods such as compression molding. In this study, bipolar plates with three different designs, i.e., parallel in series, interdigitated, and bio-inspired, were fabricated using the SLS process. The performance of these SLS-fabricated bipolar plates was studied experimentally within a fuel cell assembly under various operating conditions. The effect of temperature, relative …
Reduction Of Solid-Solid Thermal Boundary Resistance By Inserting An Interlayer, Zhi Liang, Hai-Lung Tsai
Reduction Of Solid-Solid Thermal Boundary Resistance By Inserting An Interlayer, Zhi Liang, Hai-Lung Tsai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
An Effective Method is Proposed to Greatly Improve the Thermal Transport Across the Interface between Two Solids with Dissimilar Phonon Spectra. If the Two Solids Have Similar Crystal Structure and Lattice Constant, It is Predicted from the Molecular Dynamics Modeling that an over 50% Reduction of the Thermal Boundary Resistance Can Be Achieved by Inserting a 3-Unit-Cell-Thick Interlayer Whose Debye Temperature is Approximately the Square Root of the Product of the Debye Temperatures of the Two Solids. on the Other Hand, If the Two Solids Have a Large Difference in Lattice Constant, It is Found the Interfacial Atomic Restructuring Plays …
Phase Resolved Near-Field Mode Imaging For The Design Of Frequency-Selective Surfaces, Edward C. Kinzel, J. C. Ginn, R. L. Olmon, D. J. Shelton, B. A. Lail, I. Brenner, M. B. Sinclair, M. B. Raschke, G. D. Boreman
Phase Resolved Near-Field Mode Imaging For The Design Of Frequency-Selective Surfaces, Edward C. Kinzel, J. C. Ginn, R. L. Olmon, D. J. Shelton, B. A. Lail, I. Brenner, M. B. Sinclair, M. B. Raschke, G. D. Boreman
Mechanical and Aerospace Engineering Faculty Research & Creative Works
No abstract provided.
A Nanoporous Silicon Nitride Membrane Using A Two-Step Lift-Off Pattern Transfer With Thermal Nanoimprint Lithography, Bhargav P. Nabar, Zeynep Çelik-Butler, Brian H. Dennis, Richard E. Billo
A Nanoporous Silicon Nitride Membrane Using A Two-Step Lift-Off Pattern Transfer With Thermal Nanoimprint Lithography, Bhargav P. Nabar, Zeynep Çelik-Butler, Brian H. Dennis, Richard E. Billo
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Nanoimprint lithography is emerging as a viable contender for fabrication of large-scale arrays of 5500 nm features. A fabrication process for the realization of thin nanoporous membranes using thermal nanoimprint lithography is presented. Suspended silicon nitride membranes were fabricated by low-pressure chemical vapor deposition (LPCVD) in conjunction with a potassium hydroxide-based bulk micromachining process. Nanoscale features were imprinted into a commercially available thermoplastic polymer resist using a prefabricated silicon mold. The pattern was reversed and transferred to a thin aluminum oxide layer by means of a novel two-stage lift-off technique. The patterned aluminum oxide was used as an etch mask …
Hybrid Bioreactor For Reduction Of Capital Costs, David J. Bayless
Hybrid Bioreactor For Reduction Of Capital Costs, David J. Bayless
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A bioreactor with first and second containers has translucent sidewalls housing a plurality of planar membranes over which a slurry of water and photosynthetic microorganisms flows. A light collector is mounted adjacent a gap between the first and second containers for receiving incident light and conveying the light through optical waveguides, such as fibers, to distributors. The distributors are mounted in the first and second containers near a lower end of the substrates so that photons incident on the optical waveguides are conveyed through the optical waveguides to the light distributors and then to the lower ends of the substrates …
Advantages Of Gan Based Light-Emitting Diodes With A P-Ingan Hole Reservoir Layer, Taiping Lu, Shuti Li, Chao Liu, Kang Zhang, Yiqin Xu, Jinhui Tong, Lejuan Wu, Hailong Wang, Xiaodong Yang, Yian Yin, Guowei Xiao, Yugang Zhou
Advantages Of Gan Based Light-Emitting Diodes With A P-Ingan Hole Reservoir Layer, Taiping Lu, Shuti Li, Chao Liu, Kang Zhang, Yiqin Xu, Jinhui Tong, Lejuan Wu, Hailong Wang, Xiaodong Yang, Yian Yin, Guowei Xiao, Yugang Zhou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A p-type InGaN hole reservoir layer (HRL) was designed and incorporated in GaN based light-emitting diodes (LEDs) to enhance hole injection efficiency and alleviate efficiency droop. The fabricated LEDs with p-type HRL exhibited higher light output power, smaller emission energy shift and broadening as compared to its counterpart. Based on electrical and optical characteristics analysis and numerical simulation, these improvements are mainly attributed to the alleviated band bending in the last couple of quantum well and electron blocking layer, and thus better hole injection efficiency. Meanwhile, the efficiency droop can be effectively mitigated when the p-InGaN HRL was used.
Study Of Turbulence-Radiation Interaction In Hypersonic Turbulent Boundary Layers, L. (Lian) Duan, M. P. Martín, A. M. Feldick, M. F. Modest, D. A. Levin
Study Of Turbulence-Radiation Interaction In Hypersonic Turbulent Boundary Layers, L. (Lian) Duan, M. P. Martín, A. M. Feldick, M. F. Modest, D. A. Levin
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Direct numerical simulations are conducted to investigate the effect of turbulence-radiation interaction in hypersonic turbulent boundary layers, representative of the Orion crew exploration vehicle at the peak heating condition during reentry. Both the effects of emission and absorption are considered by solving the radiative transfer equation using the tangent slab approximation and a spectral model with line-by-line accuracy. Nondimensional governing parameters to measure the significance of turbulence-radiation interaction are proposed, and the direct numerical simulation fields with and without radiation coupling are used to assess turbulence-radiation interaction. Is it found that the fluid medium within the boundary layer is optically …
Electronic Musical Instrument To Generate Musical Tones To Imitate A Stringed Instrument, M. Nakagawa, Shun Takai, Shun Takai
Electronic Musical Instrument To Generate Musical Tones To Imitate A Stringed Instrument, M. Nakagawa, Shun Takai, Shun Takai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Provided are an electronic musical instrument, computer Storage device, and method for generating tone. A sound source in an electronic musical instrument generates a first tone at a first pitch in response to a first tone generation instruction received by an input device of the electronic musical instrument. A second tone generation instruction is received to generate a second tone at a second pitch while generating the first tone at the sound source. A determination is made of a pitch difference of the first and the second pitches. The sound source is controlled to generate the second tone and to …
Electronic Musical Instrument, M. Nakagawa, Shun Takai
Electronic Musical Instrument, M. Nakagawa, Shun Takai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Provided are an electronic musical instrument, computer storage device, and method generating tones for held notes. Indication is made of held notes having pitches as held in response to receiving note-on information for the held notes from an input device of an electronic musical instrument while receiving hold information from a hold device of the electronic musical instrument. Note-on information is received for a received note having a pitch while generating the pitches for the held notes. Selection is made of one of the held notes to release according to a first selection criteria in response to determining that the …
Adjusting A Level At Which To Generate A New Tone With A Current Generated Tone, M. Nakagawa, Shun Takai
Adjusting A Level At Which To Generate A New Tone With A Current Generated Tone, M. Nakagawa, Shun Takai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Provided are a tone control device and a method for adjusting a volume level at which to generate a new tone and at least one current tone according to a target volume level and a current volume level. A note-on event associated with a received volume level is received from an input device. A current volume level is processed to determine a new volume level in response to receiving the note-on event while generating at least one current tone at the current volume level. The at least one current tone and a new tone associated with the received note-on event …