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Multiscale Transformation Field Analysis Of Progressive Damage In Fibrous Laminates, Yehia Bahei-El-Din, Ritesh Khire, Prabhat Hajela 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, 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 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, Ziaocheng Jiang, Jinsong Hu, Lisa A. Fitzgerald, Justin C. Biffinger, Ping Xie, Bradley R. Ringeisen, Charles M. Lieber 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 …


Testing Fuel Efficiency Of Tractors With Both Continuously Variable And Standard Geared Transmissions, Christopher N. Howard 2010 University of Nebraska at Lincoln

Testing Fuel Efficiency Of Tractors With Both Continuously Variable And Standard Geared Transmissions, Christopher N. Howard

Biological Systems Engineering--Dissertations, Theses, and Student Research

A John Deere 8295R IVT tractor with a continuously variable transmission (CVT) and a John Deere 8295R PowerShift (PST) tractor (Waterloo, Iowa) with a standard geared transmission (GT) were tested for fuel consumption at three different travel speeds with six different load levels applied per speed. The JD 8295R PST tractor was tested both at full throttle (FT) and shifted up two gears and throttled back (SUTB) to achieve the same travel speed as at full throttle conditions. The three speeds tested corresponded to the maximum speeds achieved in 6th, 8th and 10th gear for the JD 8295R PST tractor …


Universality Of Non Ohmic Shunt Leakage In Thin Film Solar Cells, Sourabh Dongaonkar, J. D. Sevaites, G. M. Ford, S. Loser, J. Moore, R. M. Gelfand, H. Mohseni, H. W. Hillhouse, R. Agrawal, M. A. Ratner, T. J. Marks, Mark S. Lundstrom, Muhammad A. Alam 2010 Purdue University

Universality Of Non Ohmic Shunt Leakage In Thin Film Solar Cells, Sourabh Dongaonkar, J. D. Sevaites, G. M. Ford, S. Loser, J. Moore, R. M. Gelfand, H. Mohseni, H. W. Hillhouse, R. Agrawal, M. A. Ratner, T. J. Marks, Mark S. Lundstrom, Muhammad A. Alam

Department of Electrical and Computer Engineering Faculty Publications

http://dx.doi.org/10.1063/1.3518509

Abstract can be found at the above link


Detection And Filtering Of Landmark Occlusions Using Terrain Spatiograms, Damian M. Lyons 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 …


Knudsen Force Modeling In Application To Microsystems, Jeremy S. Nabeth, Sruti Chigullapalli, Alina A. Alexeenko 2010 Purdue University

Knudsen Force Modeling In Application To Microsystems, Jeremy S. Nabeth, Sruti Chigullapalli, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

At the microscale, even moderate temperature differences can result in significant Knudsen forces generated by the energy exchange between gas molecules and solids immersed in a gas. Creating, controlling and measuring Knudsen forces in microsystems can be an arduous task since only limited theory exists at present. This present study investigates the mechanism of Knudsen forces in detail based on numerical solution of the Boltzmann kinetic equation. The Knudsen force is shown, in general, to be a result of thermal nonequilibrium between gas and solid. The simulations are validated by comparison with experimental measurements that have been reported by Passian …


Direct Simulation Monte Carlo Modeling Of E-Beam Metal Deposition, A Venkattraman, Alina A. Alexeenko 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, A Venkattraman, Alina A. Alexeenko 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, Simina Vasilache, Nazanin Mirshahi, Soo-Yeon Ji, James Mottonen, Donald J. Jacobs, Kayvan Najarian 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, Kendra Erk, Kevin J. Henderson, Kenneth R. Shull 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, Darren Jacob Brown 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, Bradley R. Heil 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, Gabriel John Wettlaufer 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, 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 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, Daniel Finkenstadt, Duane D. Johnson 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, Nina von Prondzinski, Joanna Cybinska, Anja V. Mudring 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, Slawomir Pitula, Anja V. Mudring 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, Eric T. Psota, Lance C. Perez 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, Sunny Wan, Xiao-Hua Yu 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.


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