Modified Sandwich Structures For Improved Impact Resistance Of Wind Turbine Blades,
2010
The British University in Egypt
Modified Sandwich Structures For Improved Impact Resistance Of Wind Turbine Blades, Yehia Bahei-El-Din, Mostafa Shazly, I. El-Habbal, Y. Elbahy
Centre for Advanced Materials
Wind turbine blades are susceptible to damage due to fatigue as well as impact by flying objects and parts broken off failed blades of nearby wind towers. Localized, permanent compression of the foam core and delamination of the fibrous composite face sheets are typical damage modes and can lead to progressive structural failure. Sandwich structures modified by inclusion of flexible polyurethane (PU) layers within the cross section are examined under both impact and dynamic loads. Finite element models of sandwich structures with conventional and modified designs show that sandwich designs modified with PU interlayes exhibit reduced foam core crushing and …
Multiscale Transformation Field Analysis Of Progressive Damage In Fibrous Laminates,
2010
The British University in Egypt
Multiscale Transformation Field Analysis Of Progressive Damage In Fibrous Laminates, Yehia Bahei-El-Din, Ritesh Khire, Prabhat Hajela
Centre for Advanced Materials
As part of an ongoing effort to model uncertainty propagation across multiple scales in fibrous laminates, this paper presents a deterministic transformation field analysis for modeling damage progression under membrane forces and bending moments. In this approach, equivalent eigenstresses are computed in the phases and/or plies such that their respective stress components that satisfy the underlying failure criteria are reduced to zero. Superposition of the solutions found for the undamaged laminate under applied loads and under the eigenstress field provide the entire response. Failure criteria are based on stress averages in the fiber and matrix. Damage mechanisms considered are frictional …
The Role Of Shewanella Oneidensis Mr-1 Outer Surface Structures In Extracellular Electron Transfer,
2010
Summa-Health System
The Role Of Shewanella Oneidensis Mr-1 Outer Surface Structures In Extracellular Electron Transfer, Rachida A. Bouhenni, Gary J. Vora, Justin C. Biffinger, Sheetal Shirodkar, Ken Brockman, Ricky Ray, Peter Wu, Brandy J. Johnson, Eulandria M. Biddle, Matthew J. Marshall, Lisa A. Fitzgerald, Brenda J. Little, Jim K. Fredrickson, Alexander S. Beliaev, Bradley R. Ringeisen, Daad A. Saffarini
U.S. Navy Research
The ability of the metal reducer Shewanella oneidensis MR-1 to generate electricity in microbial fuel cells (MFCs) depends on the activity of a predicted type IV prepilin peptidase; PilD. Analysis of an S. oneidensis MR-1 pilD mutant indicated that it was deficient in pili production (Msh and type IV) and type II secretion (T2S). The requirement for T2S in metal reduction has been previously identified, but the role of pili remains largely unexplored. To define the role of type IV or Msh pili in electron transfer, mutants that lack one or both pilus biogenesis systems were generated and analyzed; …
Probing Electron Transfer Mechanisms In Shewanella Oneidensis Mr-1 Using A Nanoelectrode Platform And Single-Cell Imaging,
2010
Harvard University
Probing Electron Transfer Mechanisms In Shewanella Oneidensis Mr-1 Using A Nanoelectrode Platform And Single-Cell Imaging, Ziaocheng Jiang, Jinsong Hu, Lisa A. Fitzgerald, Justin C. Biffinger, Ping Xie, Bradley R. Ringeisen, Charles M. Lieber
U.S. Navy Research
Microbial fuel cells (MFCs) represent a promising approach for sustainable energy production as they generate electricity directly from metabolism of organic substrates without the need for catalysts. However, the mechanisms of electron transfer between microbes and electrodes, which could ultimately limit power extraction, remain controversial. Here we demonstrate optically transparent nanoelectrodes as a platform to investigate extracellular electron transfer in Shewanella oneidensis MR-1, where an array of nanoholes precludes or single window allows for direct microbeelectrode contacts. Following addition of cells, short-circuit current measurements showed similar amplitude and temporal response for both electrode configurations, while in situ optical imaging demonstrates …
Detection And Filtering Of Landmark Occlusions Using Terrain Spatiograms,
2010
Fordham University
Detection And Filtering Of Landmark Occlusions Using Terrain Spatiograms, Damian M. Lyons
Posters
A team of robots cooperating to quickly produce a map needs to share landmark information between team members so that the local maps can be accurately merged. However, a landmark visible to one robot may be partially occluded to another! Terrain Spatiograms are a landmark representation in which the image spatial information relates to the scene rather than the image. This makes it possible to identify and filter potential landmark occlusions. We present an approach to identifying and filtering occlusions using Terrain Spatiograms, and we report experimental results on 20 landmark datasets for varying states of occlusion. We show that …
Direct Simulation Monte Carlo Modeling Of E-Beam Metal Deposition,
2010
Purdue University
Direct Simulation Monte Carlo Modeling Of E-Beam Metal Deposition, A Venkattraman, Alina A. Alexeenko
School of Aeronautics and Astronautics Faculty Publications
Three-dimensional direct simulation Monte Carlo (DSMC) method is applied here to model the electron-beam physical vapor deposition of copperthin films. Various molecular models for copper-copper interactions have been considered and a suitable molecular model has been determined based on comparisons of dimensional mass fluxes obtained from simulations and previous experiments. The variable hard sphere model that is determined for atomic copper vapor can be used in DSMC simulations for design and analysis of vacuum deposition systems, allowing for accurate prediction of growth rates, uniformity, and microstructure.
Molecular Models For Dsmc Simulations Of Metal Vapor Deposition,
2010
Purdue University
Molecular Models For Dsmc Simulations Of Metal Vapor Deposition, A Venkattraman, Alina A. Alexeenko
School of Aeronautics and Astronautics Faculty Publications
The direct simulation Monte Carlo (DSMC) method is applied here to model the electron‐beam (e‐beam) physical vapor deposition of copper thin films. A suitable molecular model for copper‐copper interactions have been determined based on comparisons with experiments for a 2D slit source. The model for atomic copper vapor is then used in axi‐symmetric DSMC simulations for analysis of a typical e‐beam metal deposition system with a cup crucible. The dimensional and non‐dimensional mass fluxes obtained are compared for two different deposition configurations with non‐uniformity as high as 40% predicted from the simulations.
A Signal Processing Method To Explore Similarity In Protein Flexibility,
2010
Virginia Commonwealth University
A Signal Processing Method To Explore Similarity In Protein Flexibility, Simina Vasilache, Nazanin Mirshahi, Soo-Yeon Ji, James Mottonen, Donald J. Jacobs, Kayvan Najarian
Computer Science Publications
Understanding mechanisms of protein flexibility is of great importance to structural biology. The ability to detect similarities between proteins and their patterns is vital in discovering new information about unknown protein functions. A Distance Constraint Model (DCM) provides a means to generate a variety of flexibility measures based on a given protein structure. Although information about mechanical properties of flexibility is critical for understanding protein function for a given protein, the question of whether certain characteristics are shared across homologous proteins is difficult to assess. For a proper assessment, a quantified measure of similarity is necessary. This paper begins to …
Strain-Stiffening In Synthetic And Biopolymer Networks,
2010
Purdue University
Strain-Stiffening In Synthetic And Biopolymer Networks, Kendra Erk, Kevin J. Henderson, Kenneth R. Shull
School of Materials Engineering Faculty Publications
Strain-stiffening behavior common to biopolymer networks is difficult to reproduce in synthetic networks. Physically associating synthetic polymer networks can be an exception to this rule and can demonstrate strain-stiffening behavior at relatively low values of strain. Here, the stiffening behavior of model elastic networks of physically associating triblock copolymers is characterized by shear rheometry. Experiments demonstrate a clear correlation between network structure and strain-stiffening behavior. Stiffening is accurately captured by a constitutive model with a single fitting parameter related to the midblock length. The same model is also effective for describing the stiffening of actin, collagen, and other biopolymer networks. …
A Novel Message Routing Layer For The Communication Management Of Distributed Embedded Systems,
2010
University of Kentucky
A Novel Message Routing Layer For The Communication Management Of Distributed Embedded Systems, Darren Jacob Brown
University of Kentucky Master's Theses
Fault tolerant and distributed embedded systems are research areas that have the interest of such entities as NASA, the Department of Defense, and various other government agencies, corporations, and universities. Taking a system and designing it to work in the presence of faults is appealing to these entities as it inherently increases the reliability of the deployed system. There are a few different fault tolerant techniques that can be implemented in a system design to handle faults as they occur. One such technique is the reconfiguration of a portion of the system to a redundant resource. This is a difficult …
Distraction Osteogenesis In An Organ Culture Model,
2010
University of Kentucky
Distraction Osteogenesis In An Organ Culture Model, Bradley R. Heil
University of Kentucky Master's Theses
Distraction osteogenesis (DO) is a surgical procedure in which applied strain stimulates new bone growth; however, the underlying mechanisms by which bone cells respond to load are still uncertain. An organ culture model of DO was developed and validated by using linear distraction on the femoral shafts of 5 day old Wistar rats. Two loading regimes were utilized: distracting the bones for 2 hrs on day 1 (GRP I); distracting the bones for 2 hrs on days 1, 3, and 5 (GRP II). After 1 week in culture, the bones were compared to unloaded contralateral controls and assessed for changes. …
Merlin.Net Automation Of External Reports Verification Process,
2010
California Polytechnic State University, San Luis Obispo
Merlin.Net Automation Of External Reports Verification Process, Gabriel John Wettlaufer
Master's Theses
Merlin.net Patient Care Network is a St. Jude Medical product that is used for remote patient management. The basic concept of Merlin.net is to allow the physician to view patient device follow-up information as well as general patient and device information on a web application. The Merlin.net system also interfaces with the patient and will send them notification if they miss a follow-up. All device information will be collected automatically while the patient is sleeping. This information is sent through a telephone line to a Merlin.net server to process a report package and display the collected information on the Merlin.net …
Preparation And Characterization Of Pt/Γ-Al2o3 Model Catalyst On Nial Alloy,
2010
University of Pittsburgh
Preparation And Characterization Of Pt/Γ-Al2o3 Model Catalyst On Nial Alloy, Zhongfan Zhang, Long Li, Lin-Lin Wang, Sergio I. Sanchez, Ross V. Grieshaber, Qi Wang, Duane D. Johnson, Anatoly I. Frenkel, Ralph G. Nuzzo, Judith C. Yang
Duane D. Johnson
Numerous studies of heterogeneous catalysis systems clearly demonstrate that the metal nanoparticle (NPs)/support interaction is significant in determining the catalytic chemistry. Theoretical simulations have been performed to understand the metal/support interactions [1,2]. For example, theorists discovered that electronic and oxygen defects of γ-Al2O3 anchor the active particles [1]. Platinum NPs dispersed on γ-alumina is one of the most widely used heterogeneous catalysts and Pt performs extremely well as a catalyst for the oxygen-reduction reaction used in fuel cell industries. Hence, we chose Pt/γ-Al2O3 as a model heterogeneous catalyst system to investigate the metal NPs/support interface by electron microscopy methods with …
Interphase Energies Of Hcp Precipitates In Fcc Metals: A Density-Functional Theory Study In Al-Ag,
2010
United States Naval Academy
Interphase Energies Of Hcp Precipitates In Fcc Metals: A Density-Functional Theory Study In Al-Ag, Daniel Finkenstadt, Duane D. Johnson
Duane D. Johnson
Density-functional theory (DFT) calculations of interphase boundary energies relevant to hexagonal-close-packed (hcp) γ-precipitate formation were performed within approximate unit cells that mirror the experimental conditions in face-centered-cubic (fcc) Al-Ag solid solutions. In Al-rich, fcc Al-Ag, γ precipitates are observed to form rapidly with large (300+) aspect ratios even though the Al stacking-fault energy is high (approximately 130 mJ/m2), which should suppress hcp ribbon formation according to standard arguments. Our DFT results show why high-aspect ratio plates occur and why previous estimates based on Wulff construction were orders of magnitude less than observed values. Using DFT, we obtain a Gibbs free-energy …
Easy Access To Ultra Long-Time Stable, Luminescent Europium(Ii) Fluoride Nanoparticles In Ionic Liquids,
2010
Iowa State University
Easy Access To Ultra Long-Time Stable, Luminescent Europium(Ii) Fluoride Nanoparticles In Ionic Liquids, Nina Von Prondzinski, Joanna Cybinska, Anja V. Mudring
Anja V. Mudring
Physical vapour deposition into ionic liquids allows for the first time the synthesis of a reduced lanthanide halide on the nanoscale. The obtained EuF2 nanoparticles show a bright blue luminescence and form long-time stable-colloidal solutions in the ionic liquids.
Optical Basicity Of Ionic Liquids,
2010
Iowa State University
Optical Basicity Of Ionic Liquids, Slawomir Pitula, Anja V. Mudring
Anja V. Mudring
The concept of optical basicities initially developed by Duffy for solid oxides was successfully transferred to low melting salts such as ionic liquids (ILs). Several ionic liquids (ILs) were doped with Mn(NTf2)2 (NTf2 = bis(trifluoromethanesulfonyl)imide) as a probe to investigate the IL anion basicity by means of UV-Vis spectroscopy. The 6A1 → 4A, 4E(G) transition band of Mn2+ is influenced by the electron donor properties, i.e., Lewis basicity, of the coordinating ligands but remains—to the first order—independent from the ligand field. The change in the optical spectra for various Mn(NTf2)2 doped ILs is predominantly dependent on the anion. No significant …
The Manifestation Of Stopping Sets And Absorbing Sets As
Deviations On The Computation Trees Of Ldpc Codes,
2010
University of Nebraska-Lincoln
The Manifestation Of Stopping Sets And Absorbing Sets As Deviations On The Computation Trees Of Ldpc Codes, Eric T. Psota, Lance C. Perez
Faculty Publications from the Department of Electrical and Computer Engineering
The error mechanisms of iterative message-passing decoders for low-density parity-check codes are studied. A tutorial review is given of the various graphical structures, including trapping sets, stopping sets, and absorbing sets that are frequently used to characterize the errors observed in simulations of iterative decoding of low-density parity-check codes. The connections between trapping sets and deviations on computation trees are explored in depth using the notion of problematic trapping sets in order to bridge the experimental and analytic approaches to these error mechanisms. A new iterative algorithm for finding low-weight problematic trapping sets is presented and shown to be capable …
Facility Power Usage Modeling And Short Term Prediction With Artificial Neural Networks,
2010
California Polytechnic State University - San Luis Obispo
Facility Power Usage Modeling And Short Term Prediction With Artificial Neural Networks, Sunny Wan, Xiao-Hua Yu
Electrical Engineering
Residential and commercial buildings accounted for about 68% of the total U.S. electricity consumption in 2002. Improving the energy efficiency of buildings can save energy, reduce cost, and protect the global environment. In this research, artificial neural network is employed to model and predict the facility power usage of campus buildings. The prediction is based on the building power usage history and weather conditions such as temperature, humidity, wind speed, etc. Different neural network configurations are discussed; satisfactory computer simulation results are obtained and presented.
Application Of Self-Determination And Self-Regulation Theories To Course Design: Planting The Seeds For Adaptive Expertise,
2010
California Polytechnic State University - San Luis Obispo
Application Of Self-Determination And Self-Regulation Theories To Course Design: Planting The Seeds For Adaptive Expertise, Linda Vanasupa, Jonathan Stolk, Trevor Harding
Materials Engineering
The paper is grounded in the premise that learning occurs within a dynamic system of social and ecological interactions in the learning environment. Our intent is to open the conversation about hose ac, as engineering educators, design effective learning experiences for this dynamic system, particularly in light of the deeply ethical, adaptive expertise required of today's graduates. Drawing from two well-researched theories of psychological development (self-determination and self-regulation), we assert that fostering the engagement and positive growth required for adaptive expertise necessitates a holistic educational approach. This approach requires us to consider both the psychological needs of the learner, and …
Impaired Vascular Reactivity Following Chronic Ischemia In The Arteries Of The Mouse Hindlimb,
2010
California Polytechnic State University - San Luis Obispo
Impaired Vascular Reactivity Following Chronic Ischemia In The Arteries Of The Mouse Hindlimb, Trevor Cardinal, Thomas J. Kesler, Matthew D. Yocum, Tyler S. Smith, Nolan M. Mott
Biomedical Engineering
No abstract provided.
