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Full-Text Articles in Engineering
Cost Analysis Of Optimized Islanded Energy Systems In A Dispersed Air Base Conflict, Jay F. Pearson, Torrey J. Wagner, Justin D. Delorit
Cost Analysis Of Optimized Islanded Energy Systems In A Dispersed Air Base Conflict, Jay F. Pearson, Torrey J. Wagner, Justin D. Delorit
Faculty Publications
The United States Air Force has implemented a dispersed air base strategy to enhance mission effectiveness for near-peer conflicts. Asset dispersal places many smaller bases across a wide geographic area, which increases resupply requirements and logistical complexity. Hybrid energy systems reduce resupply requirements through sustainable, off-grid energy production. This paper presents a novel hybrid energy renewable delivery system (HERDS) model capable of (1) selecting the optimal hybrid energy system design that meets demand at the lowest net present cost and (2) optimizing the delivery of the selected system using existing Air Force cargo aircraft. The novelty of the model’s capabilities …
Proton Transfer In Molten Lithium Carbonate: Mechanism And Kinetics By Density Functional Theory Calculations, Xueling Lei, Kevin Huang, Changyong Qin
Proton Transfer In Molten Lithium Carbonate: Mechanism And Kinetics By Density Functional Theory Calculations, Xueling Lei, Kevin Huang, Changyong Qin
Faculty Publications
Using static and dynamic density functional theory (DFT) methods with a cluster model of [(Li2CO3)8H]+, the mechanism and kinetics of proton transfer in lithium molten carbonate (MC) were investigated. The migration of proton prefers an inter-carbonate pathway with an energy barrier of 8.0 kcal/mol at the B3LYP/6-31 G(d,p) level, which is in good agreement with the value of 7.6 kcal/mol and 7.5 kcal/mol from experiment and FPMD simulation, respectively. At transition state (TS), a linkage of O–H–O involving O 2p and H 1 s orbitals is formed between two carbonate ions. The calculated trajectory of H indicates that proton has …
Understanding The Benefits And Limitations Of Increasing Maximum Rotor Tip Speed For Utility-Scale Wind Turbines, Andrew Ning
Understanding The Benefits And Limitations Of Increasing Maximum Rotor Tip Speed For Utility-Scale Wind Turbines, Andrew Ning
Faculty Publications
For utility-scale wind turbines, the maximum rotor rotation speed is generally constrained by noise considerations. Innovations in acoustics and/or siting in remote locations may enable future wind turbine designs to operate with higher tip speeds. Wind turbines designed to take advantage of higher tip speeds are expected to be able to capture more energy and utilize lighter drivetrains because of their decreased maximum torque loads. However, the magnitude of the potential cost savings is unclear, and the potential trade-offs with rotor and tower sizing are not well understood. A multidisciplinary, system-level framework was developed to facilitate wind turbine and wind …
Performance Of Solid Oxide Iron-Air Battery Operated At 550°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang
Performance Of Solid Oxide Iron-Air Battery Operated At 550°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang
Faculty Publications
“Metal-air” batteries have garnered much attention in recent years due to their high intrinsic specific energy and use of inexhaustible and storage-free oxygen source -air- for the “metal-oxygen” reaction. In this study, we report theperformance of a new type of all solid-state “iron-air” battery operated at 550°C. The results show that CeO2 nanoparticles incorporated into the Fe-Fe3O4 redox-couple can improve the specific energy (Wh/kg) and round trip efficiency by 15% and 29%, respectively, over the baseline Fe-Fe3O4 battery. Use of supported Fe-Fe3O4 nanoparticles as the redox couple can increase the …
Supercritical Co2 Brayton Cycles For Solar-Thermal Energy, Brian D. Iverson, Thomas M. Conboy, James J. Pasch, Alan M. Kruizenga
Supercritical Co2 Brayton Cycles For Solar-Thermal Energy, Brian D. Iverson, Thomas M. Conboy, James J. Pasch, Alan M. Kruizenga
Faculty Publications
Of the mechanisms to improve efficiency for solar-‐thermal power plants, one of the most effective ways to improve overall efficiency is through power cycle improvements. As increases in operating temperature continue to be pursued, supercritical CO2 Brayton cycles begin to look more attractive despite the development costs of this technology. Further, supercritical CO2 Brayton has application in many areas of power generation beyond that for solar energy alone.
One challenge particular to solar-‐thermal power generation is the transient nature of the solar resource. This work illustrates the behavior of developmental Brayton turbomachinery in response to a fluctuating thermal input, much …
Grain Boundary Property Determination Through Measurement Of Triple Junction Geometry And Crystallography, Brent L. Adams, D. Casasent, M. Demirel, Bassem S. El-Dasher, D. Kinderlehrer, C. Liu, I. Livshits, F. Manolache, D. Mason, A. Morawiec, W. W. Mullins, S. Ozdemir, Gregory S. Rohrer, Anthony D. Rollett, David M. Saylor, Shlomo Ta'asan, A. Talukder, Chialin T. Wu, C. C. Yang, W. Yang
Grain Boundary Property Determination Through Measurement Of Triple Junction Geometry And Crystallography, Brent L. Adams, D. Casasent, M. Demirel, Bassem S. El-Dasher, D. Kinderlehrer, C. Liu, I. Livshits, F. Manolache, D. Mason, A. Morawiec, W. W. Mullins, S. Ozdemir, Gregory S. Rohrer, Anthony D. Rollett, David M. Saylor, Shlomo Ta'asan, A. Talukder, Chialin T. Wu, C. C. Yang, W. Yang
Faculty Publications
This work was supported primarily by the MRSEC program of the National Science Foundation under Award Number DMR-0079996. Microstructure controls the properties of most useful materials. Thus an ability to control microstructure through the processing of materials is a key to optimization of materials performance. Most materials are polycrystalline and their grain structure is a very important aspect of their microstructure. Thanks to their complexity there is a great variety of grain boundary types even in relatively isotropic materials such as the cubic metals. Simply describing the crystallography requires five (macroscopic) parameters (e.g. disorientation and inclination). Evidently, acquiring a knowledge …
Reducing Energy In Fpga Multipliers Through Glitch Reduction - Clock Power And Digit-Serial Addendum, Nathaniel Rollins, Michael J. Wirthlin
Reducing Energy In Fpga Multipliers Through Glitch Reduction - Clock Power And Digit-Serial Addendum, Nathaniel Rollins, Michael J. Wirthlin
Faculty Publications
Sponsorship: NASA. In a previous paper it was shown that reducing the amount of glitches in digital designs can significantly reduce the amount of dynamic power consumption. Pipelined multipliers and a bit-serial multiplier design were used to show this. The paper failed to mention how much of the dynamic power consumption was due to the clock distribution. Also the only digit- serial multiplier digit size investigated was a digit size of 1. This paper addresses the issue of dynamic clocking power and includes results of digit-serial multipliers with larger digit sizes.
The Effect Of Reactor Configuration On No Conversion And Energy Consumption In Non-Thermal Plasma Parallel Tube Reactors, Morris D. Argyle, Gui-Bing Zhao, S.V.B. Janardhan Garikipati, Xudong Hu, Maciej Radosz
The Effect Of Reactor Configuration On No Conversion And Energy Consumption In Non-Thermal Plasma Parallel Tube Reactors, Morris D. Argyle, Gui-Bing Zhao, S.V.B. Janardhan Garikipati, Xudong Hu, Maciej Radosz
Faculty Publications
This work shows that the configuration of a pulsed corona discharge reactor strongly affects the rate of electron collision reactions. Experiments involving the decomposition of NO in N2 were performed in a reactor in which the number or parallel reactor tubes varied from 1 to 10 at a constant pressure of 147.6 kPa and ambient temperature. A previously developed lumped model of the reactions accurately predicted the effects of varying the initial concentrations of NO (from 240ppm to 593ppm) and gas residence time (from 1.93 to 742 s). With an increasing number of parallel reactor tubes, the rate of the …