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2011

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Full-Text Articles in Engineering

Aerosol-Assisted Synthesis Of Monodisperse Single-Crystalline Α-Cristobalite Nanospheres, Xingmao Jiang, Lihong Bao, Yung-Sung Cheng, Darren R. Dunphy, Xiaodong Li, C. Jeffrey Brinker Dec 2011

Aerosol-Assisted Synthesis Of Monodisperse Single-Crystalline Α-Cristobalite Nanospheres, Xingmao Jiang, Lihong Bao, Yung-Sung Cheng, Darren R. Dunphy, Xiaodong Li, C. Jeffrey Brinker

Faculty Publications

Monodisperse single-crystalline α-cristobalite nanospheres have been synthesized by hydrocarbon-pyrolysis-induced carbon deposition on amorphous silica aerosol nanoparticles, devitrification of the coated silica at high temperature, and subsequent carbon removal by oxidation. The nanosphere size can be well controlled by tuning the size of the colloidal silica precursor. Uniform, high-purity nanocrystalline α-cristobalite is important for catalysis, nanocomposites, advanced polishing, and understanding silica nanotoxicology.


Bonding Of Polydimethylsiloxane Microfluidics To Silicon-Based Sensors, Long-Fang Tsai, William C. Dahlquist, Seunghyun Kim, Gregory P. Nordin Nov 2011

Bonding Of Polydimethylsiloxane Microfluidics To Silicon-Based Sensors, Long-Fang Tsai, William C. Dahlquist, Seunghyun Kim, Gregory P. Nordin

Faculty Publications

We investigate bonding polydimethylsiloxane (PDMS) to silicon using a thin (~2μm) intermediate adhesive layer stamped onto a PDMS piece prior to bonding. In particular, we compare as adhesive layers Sylgard 184 and 182 curing agents and a UV curable adhesive (NOA 75). We examine the effect of both curing temperature and duration on curing agent bond strength. Bond strengths for the different adhesives are determined by measuring the average burst pressure at a PDMS-silicon interface using a PDMS test design. We find that Sylgard 184 curing agent gives the highest bond strength with burst pressure of 700 kPa or more …


One-Step Infiltration Of Mixed Conducting Electrocatalysts For Reducing Cathode Polarization Of A Commercial Cathode-Supported Sofc, Nansheng Xu, Xue Li, Xuan Zhao, Hailei Zhao, Kevin Huang Nov 2011

One-Step Infiltration Of Mixed Conducting Electrocatalysts For Reducing Cathode Polarization Of A Commercial Cathode-Supported Sofc, Nansheng Xu, Xue Li, Xuan Zhao, Hailei Zhao, Kevin Huang

Faculty Publications

Infiltrating fine-grained electrocatalyst particles of either ion conducting or mixed electron and ion conducting (MEIC) material into a ceramic porous electrode scaffold has proven a very effective way to improve electrode performance for low to intermediate temperature solid oxide fuel cells (SOFCs). We report here one-step infiltration of MEIC fine particles, La0.6Sr0.4CoO3-δ (LSCo) and SrCo0.8Fe0.2O3-δ (SCF), into a commercial cathode substrate. A comparative study shows that the cathode polarization can be considerably reduced by a factor of 17 to 28 and 28 to 49 from 1000 to 700 ³C by …


Analysis Of Coal By Static Time-Of-Flight Secondary Ion Mass Spectrometry (Tof-Sims), Lei Pei, Guilin Jiang, Larry Lin Baxter, Matthew R. Linford Nov 2011

Analysis Of Coal By Static Time-Of-Flight Secondary Ion Mass Spectrometry (Tof-Sims), Lei Pei, Guilin Jiang, Larry Lin Baxter, Matthew R. Linford

Faculty Publications

Coal remains a primary fuel for power generation. Herein we present time-of-flight secondary ion mass spectra (ToF-SIMS data) taken with a Ga primary ion beam from ca. 30 coal specimens. These commercially different coal specimens were obtained from coal mining companies and/or power plants. They represent all major coal types used in power generation (bituminous coals, subbituminous coals, and lignites), and include low-rank materials (lignites and subbituminouscoals), which are represented as a minor portion of the data. Often, inorganic ions (Na, Al, Si,and K) are pronounced in the spectra, overshadowing peaks from organic moieties. This reflectsthe high sensitivity of SIMS …


Giant Magnetostriction In Annealed Co1-XFeX Thin-Films, Dwight Hunter, Will Osborn, Ke Wang, Nataliya Kazantseva, Jason R. Hattrick-Simpers, Richard Suchoski, Ryota Takahashi, Marcus L. Young, Apurva Mehta, Leonid A. Bendersky, Same E. Lofland, Manfred Wuttig, Ichiro Takeuchi Nov 2011

Giant Magnetostriction In Annealed Co1-XFeX Thin-Films, Dwight Hunter, Will Osborn, Ke Wang, Nataliya Kazantseva, Jason R. Hattrick-Simpers, Richard Suchoski, Ryota Takahashi, Marcus L. Young, Apurva Mehta, Leonid A. Bendersky, Same E. Lofland, Manfred Wuttig, Ichiro Takeuchi

Faculty Publications

Chemical and structural heterogeneity and the resulting interaction of coexisting phases can lead to extraordinary behaviours in oxides, as observed in piezoelectric materials at morphotropic phase boundaries and relaxor ferroelectrics. However, such phenomena are rare in metallic alloys. Here we show that, by tuning the presence of structural heterogeneity in textured Co1−xFex thin films, effective magnetostriction λeff as large as 260 p.p.m. can be achieved at low-saturation field of ~10 mT. Assuming λ100 is the dominant component, this number translates to an upper limit of magnetostriction ofλ100≈5λeff >1,000 p.p.m. Microstructural analyses …


A Novel Solid Oxide Redox Flow Battery For Grid Energy Storage, Nansheng Xu, Xue Li, Xuan Zhao, John B. Goodenough, Kevin Huang Oct 2011

A Novel Solid Oxide Redox Flow Battery For Grid Energy Storage, Nansheng Xu, Xue Li, Xuan Zhao, John B. Goodenough, Kevin Huang

Faculty Publications

In this work we report proof-of-concept of a novel redox flow battery consisting of a solid oxide electrochemical cell (SOEC) integrated with a redox-cycle unit. The charge/discharge characteristics were explicitly observed by operating between fuel cell and electrolysis modes of the SOEC along with “in-battery” generation and storage of H2 realized by an in situ closed-loop reversible steam-metal reaction in the redox-cycle unit. With Fe/FeO as the redox materials, the new storage battery can produce an energy capacity of 348 Wh/kg-Fe and round-trip efficiency of 91.5% over twenty stable charge/discharge cycles. This excellent performance combined with robustness, environmental friendliness …


Synthesis, Structural, Optical And Mechanical Characterization Of Srb2O4 Nanorods, Rui Li, Lihong Bao, Xiaodong Li Oct 2011

Synthesis, Structural, Optical And Mechanical Characterization Of Srb2O4 Nanorods, Rui Li, Lihong Bao, Xiaodong Li

Faculty Publications

Single crystalline strontium borate (SrB2O4) nanorods were synthesized for the first time via a facile sol–gel route at low temperature. The SrB2O4 nanorods have a good crystalline nature with the growth direction along the [511] orientation and they are transparent from the ultraviolet to the visible regimes. Nanoscale three-point bending tests were performed directly on individual nanorods to probe their mechanical properties using an atomic force microscope. The elastic modulus of SrB2O4 nanorods was measured to be 158.2 ± 2.8 GPa, exhibiting a significant increase compared with other borate nanostructures …


Supported Monoethanolamine For Co2 Separation, Morris D. Argyle, Zhuoyan Sun, Maohong Fan Oct 2011

Supported Monoethanolamine For Co2 Separation, Morris D. Argyle, Zhuoyan Sun, Maohong Fan

Faculty Publications

An alternative method for using monoethanolamine (MEA) in CO2 separation is developed from the viewpoints of the MEA-CO2 reaction environment and the process of spent sorbent regeneration. The method could be used to considerably reduce energy consumption compared to conventional aqueous MEA processes. MEA-TiO2 (MT) CO2 sorbent is synthesized using pure MEA and a support material, TiO2. The performance of the MT sorbent on CO2 separation was investigated in tubular reactors under various experimental conditions. The effects of several major factors on CO2 sorption by the MT sorbent were investigated. The sorption capacity of the MT sorbent increased with MEA …


Utilizing An Improved Rotorcraft Dynamic Model In State Estimation, Timothy Mclain, Randal W. Beard, Robert C. Leishman, John Macdonald, Jeffrey L. Ferrin, Stephen C. Quebe Sep 2011

Utilizing An Improved Rotorcraft Dynamic Model In State Estimation, Timothy Mclain, Randal W. Beard, Robert C. Leishman, John Macdonald, Jeffrey L. Ferrin, Stephen C. Quebe

Faculty Publications

Multirotor aircraft have become a popular platform for indoor flight. To navigate these vehicles indoors through an unknown environment requires the use of a SLAM algorithm, which can be processing intensive. However, their size, weight, and power capacity limit the processing capabilities available onboard. In this paper, we describe an approach to state estimation that helps to alleviate this problem. By using an improved dynamic model we show how to more accurately estimate the aircraft states than can be done with the traditional approach of integrating IMU measurements. The estimation is done with relatively infrequent corrections from accelerometers (40Hz) and …


Differential Flatness Based Control Of A Rotorcraft For Aggressive Maneuvers, Timothy Mclain, Randal W. Beard, Robert C. Leishman, Jeffrey L. Ferrin Sep 2011

Differential Flatness Based Control Of A Rotorcraft For Aggressive Maneuvers, Timothy Mclain, Randal W. Beard, Robert C. Leishman, Jeffrey L. Ferrin

Faculty Publications

We propose a new method to control a multi-rotor aerial vehicle. We show that the system dynamics are differentially flat. We utilize the differential flatness of the system to provide a feed forward input. The system model derived allows for arbitrary changes in yaw and is not limited to small roll and pitch angles. We demonstrate in hardware the ability to follow a highly maneuverable path while tracking a time-varying heading command.


Thermal Model For Lithium Ion Battery Pack With Mixed Parallel And Series Configuration, Meng Guo, Ralph E. White Aug 2011

Thermal Model For Lithium Ion Battery Pack With Mixed Parallel And Series Configuration, Meng Guo, Ralph E. White

Faculty Publications

In this work, a mathematical thermal model for lithium ion battery pack with specific configuration was developed by coupling the single particle model and energy balance equation with basic circuit constraints. The temperature variation at different parts of the battery pack was considered in charge/discharge operations, and the dependency of cell parameters on temperature were taken into account. The model was validated by comparing the simulated current, voltage, and temperature profiles with experimental data. Case studies such as battery balancing and circuit interruption were also performed and discussed.


In Situ Synthesis Of Ultrafine Ss-Mno2/Polypyrrole Nanorod Composites For High-Performance Supercapacitors, Jianfeng Zang, Xiaodong Li Aug 2011

In Situ Synthesis Of Ultrafine Ss-Mno2/Polypyrrole Nanorod Composites For High-Performance Supercapacitors, Jianfeng Zang, Xiaodong Li

Faculty Publications

We report a remarkable observation that is at odds with the established notion that β-MnO2 was regarded as an undesirable candidate for supercapacitor applications. The specific capacitance of β-MnO2 can reach as high as 294 F g−1, which is comparable to the best crystallographic structure, like α-MnO2. The key is to substantially decrease the size of β-MnO2 powders to ultra small regime. We demonstrate a facile, simple, and effective approach to synthesizing ultrafine (<10 nm in diameter) β-MnO2/polypyrrole nanorod composite powders for high-performance supercapacitor electrodes. Our observation may encourage a revisit of the other good …


Characteristics Of The Hydrogen Electrode In High Temperature Steam Electrolysis Process, Chao Jin, Chenghao Yang, Fanglin Chen Aug 2011

Characteristics Of The Hydrogen Electrode In High Temperature Steam Electrolysis Process, Chao Jin, Chenghao Yang, Fanglin Chen

Faculty Publications

YSZ-electrolyte supported solid oxide electrolyzer cells (SOECs) using LSM-YSZ oxygen electrode but with three types of hydrogen electrode, Ni–SDC, Ni–YSZ and LSCM–YSZ have been fabricated and characterized under different steam contents in the feeding gas at 850°C. Electrochemical impedance spectra results show that cell resistances increase with the increase in steam concentrations under both open circuit voltage and electrolysis conditions, suggesting that electrolysis reaction becomes more difficult in high steam content. Pt reference electrode was applied to evaluate the contributions of the hydrogen electrode and oxygen electrode in the electrolysis process. Electrochemical impedance spectra and over potential of both electrodes …


Transcriptional Analysis Of Lactobacillus Brevis To N-Butanol And Ferulic Acid Responses, James Winkler, Katy Kao Aug 2011

Transcriptional Analysis Of Lactobacillus Brevis To N-Butanol And Ferulic Acid Responses, James Winkler, Katy Kao

Faculty Publications

BackgroundThe presence of anti-microbial phenolic compounds, such as the model compound ferulic acid, in biomass hydrolysates pose significant challenges to the widespread use of biomass in conjunction with whole cell biocatalysis or fermentation. Currently, these inhibitory compounds must be removed through additional downstream processing or sufficiently diluted to create environments suitable for most industrially important microbial strains. Simultaneously, product toxicity must also be overcome to allow for efficient production of next generation biofuels such as n-butanol, isopropanol, and others from these low cost feedstocks.Methodology and Principal FindingsThis study explores the high ferulic acid and n-butanol tolerance in Lactobacillus brevis, a …


Simulation Of Dna Extension In Nanochannels, Yanwei Wang, Douglas R. Tree, Kevin D. Dorfman Jul 2011

Simulation Of Dna Extension In Nanochannels, Yanwei Wang, Douglas R. Tree, Kevin D. Dorfman

Faculty Publications

We have used a realistic model for double-stranded DNA and Monte Carlo simulations to compute the extension (mean span) of a DNA molecule confined in a nanochannel over the full range of confinement in a high ionic strength buffer. The simulation data for square nanochannels resolve the apparent contradiction between prior simulation studies and the predictions from Flory theory, demonstrating the existence of two transition regimes between weak confinement (the de Gennes regime) and strong confinement (the Odijk regime). The simulation data for rectangular nanochannels support the use of the geometric mean for mapping data obtained in rectangular channels onto …


Desorption Kinetics Of An Alternative Monoethanolamine Based Co2 Capture Process, Morris D. Argyle, Zhuoyan Sun, Maohong Fan Jul 2011

Desorption Kinetics Of An Alternative Monoethanolamine Based Co2 Capture Process, Morris D. Argyle, Zhuoyan Sun, Maohong Fan

Faculty Publications

Supported monoethanolamine (MEA) sorbents are promising materials for CO2 separation due to their low energy demands. Like any other CO2 separation technologies, CO2 desorption from supported MEA sorbents is the most energy-expensive step in the overall CO2 separation process. The presence of water during CO2 desorption process leads to a significant increase in energy consumption. Therefore, CO2 desorption in the absence of water is an important method to reduce energy consumption of CO2 separation using supported MEA, which is determined by several major factors, including desorption kinetics. However, study on CO2 desorption kinetics of supported MEA is lacking. This research …


Jet Propellant 8 Versus Alternative Jet Fuels, Peter Feng, Wayne C. Kinsel, Alfred E. Thal Jr., Charles A. Bleckmann Jul 2011

Jet Propellant 8 Versus Alternative Jet Fuels, Peter Feng, Wayne C. Kinsel, Alfred E. Thal Jr., Charles A. Bleckmann

Faculty Publications

The Air Force is the largest user of jet fuel in the Department of Defense DOD, consuming 2.4 billion gallons per year. In light of environmental impacts associated with using nonrenewable fuel sources and national security concerns regarding dependency on foreign oil, it is no surprise that the United States is paying more attention to alternative fuels. Both DOD and Air Force energy strategies address the need to develop and produce such fuels. The DOD has made a commitment to energy security, establishing an energy initiative that strives to modernize infrastructure, increase utility and energy conservation, enhance demand reduction, and …


Precision Position, Navigation, And Timing Without The Global Positioning System, Kenneth A. Fisher, John F. Raquet Jul 2011

Precision Position, Navigation, And Timing Without The Global Positioning System, Kenneth A. Fisher, John F. Raquet

Faculty Publications

The NAVSTAR Global Positioning System GPS has revolutionized modern warfare. Since 2005 almost all US precision-guided munitions have used GPS targeting data. Consequently, weapons delivery systems are able to strike enemy targets with precision, often resulting in little or no collateral damage. Furthermore, nearly all military assets, including aircraft, tanks, ships, missiles, mortar rounds, cargo boxes, and dismounted Soldiers rely on the accurate position determination that GPS provides. For military users of this system, two main limitations emerge. First, the system relies on line of sight that is, the satellites must be in view of the receiver s antenna so …


A Taskable Space Vehicle: Realizing Cost Savings By Combining Orbital And Suborbital Flight, Thomas Co, Jonathan T. Black Jul 2011

A Taskable Space Vehicle: Realizing Cost Savings By Combining Orbital And Suborbital Flight, Thomas Co, Jonathan T. Black

Faculty Publications

The use of space gives the United States distinct advantages in any battlefield environment, but the high cost of space operations increasingly jeopardizes those advantages. Although the United States pioneered much of the current space technology, declining budgets for space research, development, and operations leave our legacy systems vulnerable to adversaries around the world. Other nations formerly incapable of space exploitation are quickly learning to counter US space technologies at surprisingly low costs. In order to reduce the expense of deploying and maintaining a robust space capability, the Department of Defense (DOD) must change the status quo in space operations …


Unintended Consequences: Potential Downsides Of The Air Force's Conversion To Biofuels, Mark N. Goltz, Charles A. Bleckmann, Charles M. Mackay, Khai Vuong, Jerrod P. Mccomb Jul 2011

Unintended Consequences: Potential Downsides Of The Air Force's Conversion To Biofuels, Mark N. Goltz, Charles A. Bleckmann, Charles M. Mackay, Khai Vuong, Jerrod P. Mccomb

Faculty Publications

The desire to reduce US dependence on foreign energy, ongoing environmental concerns, and the rising cost of petroleum have sparked significant development of greener alternative and renewable energy sources such as alcohol-based biofuels. To address these issues, the Department of Defense DOD has moved to diminish its reliance on petroleum for fueling aircraft and ground equipment. The US Air Force, in alignment with DOD objectives, has initiated several goals for reducing its use of energy: (1) decrease the use of petroleum-based fuel by 2 percent annually for the vehicle fleet, (2) increase the use of alternative fuel in motor vehicles …


Using Nanotechnology To Detect Nerve Agents, Mark N. Goltz, Dong-Shik Kim, Leeann Racz Jul 2011

Using Nanotechnology To Detect Nerve Agents, Mark N. Goltz, Dong-Shik Kim, Leeann Racz

Faculty Publications

Nanotechnology has opened a wide range of opportunities having potential impacts in areas as diverse as medicine and consumer products. In collaboration with researchers at the University of Toledo UT, Air Force Institute of Technology AFIT scientists are exploring the possibility of using a nanoscale organic matrix to detect organophosphate OP nerve agents. Current techniques for detecting OP compounds are expensive and time consuming. Developing a nanoscale organic matrix sensor would allow for direct, real-time sensing under field conditions. This article describes the science behind such a sensor and its possible applications. High-performance sensors are needed to protect Soldiers and …


Achieving The Air Force’S Energy Vision, Frederick G. Harmon, Richard D. Branam, Doral E. Sandlin Jul 2011

Achieving The Air Force’S Energy Vision, Frederick G. Harmon, Richard D. Branam, Doral E. Sandlin

Faculty Publications

The US Air Force is the largest consumer of energy in the federal government, spending 9 billion in 2008 to fuel aircraft and ground vehicles as well as provide energy to installations.1 In that same year, the Air Force s fuel bill of 7 billion amounted to more than half of the US government s total fuel cost.2 Because of the critical and central role that energy plays in completion of the Air Force’s mission, the secretary of the Air Force has developed an Air Force energy plan supported by three pillars Reduce Demand, Increase Supply, and Culture …


Aerospike Rockets For Increased Space Launch Capability, Carl R. Hartsfield, Richard D. Branam, Joshua N. Hall, Joseph R. Simmons Iii Jul 2011

Aerospike Rockets For Increased Space Launch Capability, Carl R. Hartsfield, Richard D. Branam, Joshua N. Hall, Joseph R. Simmons Iii

Faculty Publications

No abstract provided.


X-Hale: Designing The Atmospheric Surveillance Platforms Of The Future, Christopher M. Shearer Jul 2011

X-Hale: Designing The Atmospheric Surveillance Platforms Of The Future, Christopher M. Shearer

Faculty Publications

Imagine the benefits that battlefield commanders or intelligence analysts could derive from an airborne surveillance platform that would carry a 500-pound payload, operate above the range of small arms fire, remain on station for weeks or even years, cost much less than a satellite, and relocate around the globe to a new region of interest within a couple of weeks. Realizing this concept, known as a high-altitude, long-endurance HALE aircraft, is a 10-to-15-year goal of researchers at the Air Force Institute of Technology AFIT. In order to reach this goal, those researchers are following a developmental path similar to the …


Gis-Based Data Model And Tools For Creating And Managing Two-Dimensional Cross Sections, Timothy L. Whiteaker, Norm Jones, Gil Strassberg, Alan Lemon, Doug Gallup Jun 2011

Gis-Based Data Model And Tools For Creating And Managing Two-Dimensional Cross Sections, Timothy L. Whiteaker, Norm Jones, Gil Strassberg, Alan Lemon, Doug Gallup

Faculty Publications

While modern Geographic Information Systems (GIS) software is robust in handling maps and data in plan view, the software generally falls short when representing features in section view. Further complicating the issue is the fact that geologic cross sections are often drawn by connecting a series of wells together that do not fall along a single straight line. In this case, the x-axis of the cross section represents the distance along the set of individual lines connecting the series of wells, effectively “flattening out” the cross section along this path to create a view of the subsurface with which …


Developing And Assessing Stem Curriculum With The Intent Of Promoting Technological Literacy, Scott Bartholomew, Geoff Wright, Ron Terry Jun 2011

Developing And Assessing Stem Curriculum With The Intent Of Promoting Technological Literacy, Scott Bartholomew, Geoff Wright, Ron Terry

Faculty Publications

Developing and Assessing STEM Curriculum with the Intent of Promoting Technological Literacy Technological literacy is a key component of President Barack Obama’s $260 Million STEM educational initiative (Office of the Press Secretary, 2009). Central to his plan is STEM teacher training and curriculum development. Both of these issues were addressed and are currently being measured by the research outlined in this paper. Spring2010 a collection of technology and engineering education graduate students developed with mentoring from two technology and engineering education professors 20 lesson unit and lesson plans promoting technological literacy. The lesson plans are currently being used and assessed …


A Generic Bamboo-Based Carbothermal Method For Preparing Carbide (Sic, B4C, Tic, Tac, Nbc, TiXNb1-XC, And TaX Nb1-XC) Nanowires, Xinyong Tao, Yiping Li, Jun Du, Yang Xia, Yingchao Yang, Hui Huang, Yongping Gan, Wenkui Zhang, Xiaodong Li Jun 2011

A Generic Bamboo-Based Carbothermal Method For Preparing Carbide (Sic, B4C, Tic, Tac, Nbc, TiXNb1-XC, And TaX Nb1-XC) Nanowires, Xinyong Tao, Yiping Li, Jun Du, Yang Xia, Yingchao Yang, Hui Huang, Yongping Gan, Wenkui Zhang, Xiaodong Li

Faculty Publications

Finding a general procedure to produce a whole class of materials in a similar way is a desired goal of materials chemistry. In this work, we report a new bamboo-based carbothermal method to prepare nanowires of covalent carbides (SiC and B4C) and interstitial carbides (TiC, TaC, NbC, TixNb1−xC, and TaxNb1−xC). The use of natural nanoporous bamboo as both the renewable carbon source and the template for the formation of catalyst particles greatly simplifies the synthesis process. Based on the structural, morphological and elemental analysis, volatileoxides or halides assisted …


Efficient Application Programming Interface For Multi-Dimensional Modeling Data, Norman L. Jones, Robert M. Wallace, Russell Jones, Cary Butler, Alan Zundel Jun 2011

Efficient Application Programming Interface For Multi-Dimensional Modeling Data, Norman L. Jones, Robert M. Wallace, Russell Jones, Cary Butler, Alan Zundel

Faculty Publications

This paper describes an Application Programming Interface (API) for managing multi-dimensional data produced for water resource computational modeling that is being developed by the US Army Engineer Research and Development Center (ERDC), in conjunction with Brigham Young University. This API, along with a corresponding data standard, is being implemented within ERDC computational models to facilitate rapid data access, enhanced data compression and data sharing, and cross-platform independence. The API and data standard are known as the eXtensible Model Data Format (XMDF), and version 1.3 is available for free download. This API is designed to manage geometric data associated with grids, …


Assessment Of First Year Experiences At Sjsu, Patricia Backer, Emily Allen, Janet Sundrud Jun 2011

Assessment Of First Year Experiences At Sjsu, Patricia Backer, Emily Allen, Janet Sundrud

Faculty Publications

With nearly 5,000 students, the Charles W. Davidson College of Engineering (CoE) at San José State University (SJSU) is the largest provider of engineers to Silicon Valley companies and is ranked 12th among engineering programs for master’s-level institutions in the 2009 U.S. News &World Report's listing of "America’s Best Colleges. “Our overarching theoretical model for student retention is based on Tinto’s model. We adapted this model, based on additional research, to address the needs of students at SJSU. According to this model, effective and positive interactions in college should increase the student’s commitment and effort in college, and thereby, increase …


Compressibility Effects Of Extended Formation Flight, Andrew Ning, Ilan Kroo Jun 2011

Compressibility Effects Of Extended Formation Flight, Andrew Ning, Ilan Kroo

Faculty Publications

Aircraft flown in formations may realize significant reductions in induced drag by flying in regions of wake upwash. However, most transports fly at transonic speeds and compressibility effects in formation flight are not well understood. This study uses an Euler solver to analyze the inviscid aerodynamic forces and moments of transonic wing/body configurations flying in a 2-aircraft formation. We consider formations with large streamwise separation distances (10-50 wingspans) in an arrangement we term extended formation flight. Compressibility-related drag penalties in formation flight may be eliminated by slowing 2-3% below the nominal out-of-formation drag divergence Mach number, at fixed lift coefficient …