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Articles 1231 - 1260 of 3295

Full-Text Articles in Engineering

Development Of A Vortex Particle Code For The Modeling Of Wake Interaction In Distributed Propulsion, Eduardo Alvarez, Andrew Ning Jun 2018

Development Of A Vortex Particle Code For The Modeling Of Wake Interaction In Distributed Propulsion, Eduardo Alvarez, Andrew Ning

Faculty Publications

Recent developments in electric aircraft technology have enabled the use of distributed propulsion for the next generation of vertical lift vehicles. However, the ability to rapidly assess the performance of these design concepts, with sufficient fidelity, is a current weakness of this nascent industry. This paper explores the capacity of the viscous Vortex Particle Method (VPM) to model wake interactions found in distributed propulsion. The elements of the vortex particle method are summarized, and a new approach for the calculation of vortex stretching through the complex-step derivative approximation is presented. Preliminary validation is performed on vortex ring cases resembling the …

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Universal Airfoil Parametrization Using B-Splines, Dev Rajnarayan, Andrew Ning, Judd Mehr Jun 2018

Universal Airfoil Parametrization Using B-Splines, Dev Rajnarayan, Andrew Ning, Judd Mehr

Faculty Publications

In this paper, we apply well-known techniques for parametric curves to the definition and deformation of airfoil sections. While it has already been shown that many versions of Kulfan’s Class Shape Transformation (CST) are exactly equivalent to Bézier curves, we show here that all NACA 4-digit thickness distributions and the PARSEC parametrization of Sobiezcky are also higher-order Bézier curves. As with CST, Béziers and B-Splines provide direct control over aerodynamically meaningful features such as nose radius and boat-tail angle, but also provide more a intuitive parametrization of the rest of the airfoil surface. We show the efficacy of B-Spline-based parametrizations …

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Photovoltaic System Optimization For An Austere Location Using Time Series Data, Torrey J. Wagner, Eric Lang, Warren Assink, Douglas S. Dudis Jun 2018

Photovoltaic System Optimization For An Austere Location Using Time Series Data, Torrey J. Wagner, Eric Lang, Warren Assink, Douglas S. Dudis

Faculty Publications

In this work we test experimental photovoltaic, storage and generator technologies and investigate their potential to meet austere location energy needs. After defining the energy requirements and insolation of a 1,100-person base, we develop a microgrid model and simulation. Cost optimizations were then performed using hourly time-series data to explore the cost and performance trade-space of a PV-battery-generator system. The work highlights the cost of resiliency and the dependencies of optimum system component sizes on duration and the fully burdened cost of fuel.

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Synthesis-Structure-Activity Relationships In Co3o4 Catalyzed Co Oxidation, Kathleen Mingle, Jochen A. Lauterbach May 2018

Synthesis-Structure-Activity Relationships In Co3o4 Catalyzed Co Oxidation, Kathleen Mingle, Jochen A. Lauterbach

Faculty Publications

In this work, a statistical design and analysis platform was used to develop cobalt oxide based oxidation catalysts prepared via one pot metal salt reduction. An emphasis was placed upon understanding the effects of synthesis conditions, such as heating regimen and Co2+ concentration on the metal salt reduction mechanism, the resultant nanomaterial properties (i.e., size, crystal structure, and crystal faceting), and the catalytic activity in CO oxidation. This was accomplished by carrying out XRD, TEM, and FTIR studies on synthesis intermediates and products. Additionally, high-throughput experimentation was employed to study the performance of Co3O4 oxidation catalysts over a wide range …

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Range Information Characterization Of The Hokuyo Ust-20lx Lidar Sensor, Matthew A. Cooper, John F. Raquet, Rick Patton May 2018

Range Information Characterization Of The Hokuyo Ust-20lx Lidar Sensor, Matthew A. Cooper, John F. Raquet, Rick Patton

Faculty Publications

This paper presents a study on the data measurements that the Hokuyo UST-20LX Laser Rangefinder produces, which compiles into an overall characterization of the LiDAR sensor relative to indoor environments. The range measurements, beam divergence, angular resolution, error effect due to some common painted and wooden surfaces, and the error due to target surface orientation are analyzed. It was shown that using a statistical average of sensor measurements provides a more accurate range measurement. It was also shown that the major source of errors for the Hokuyo UST-20LX sensor was caused by something that will be referred to as “mixed …

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Analyzing Operating And Support Costs For Air Force Aircraft, Scott C. Hewitson, Jonathan D. Ritschel, Edward D. White, Gregory Brown May 2018

Analyzing Operating And Support Costs For Air Force Aircraft, Scott C. Hewitson, Jonathan D. Ritschel, Edward D. White, Gregory Brown

Faculty Publications

Purpose: Recent legislation resulted in an elevation of operating and support (O&S) costs’ relative importance for decision-making in Department of Defense programs. However, a lack of research in O&S hinders a cost analyst’s abilities to provide accurate sustainment estimates. Thus, the purpose of this paper is to investigate when Air Force aircraft O&S costs stabilize and to what degree. Next, a parametric O&S model is developed to predict median O&S costs for use as a new tool for cost analyst practitioners.
Design/Methodology/Approach: Utilizing the Air Force total ownership cost database, 44 programs consisting of 765 observations from 1996 to 2016 …

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Baseline Effects Of Lysophosphatidylcholine And Nerve Growth Factor In A Rat Model Of Sciatic Nerve Regeneration After Crush Injury, Ryan L. Wood, Keaton S. Karlinsey, Austin D. Thompson, Mark N. Rigby, Greggory D. Boatright, William G. Pitt, Beverly L. Roeder, Scott C. Steffersen, Alonzo D. Cook May 2018

Baseline Effects Of Lysophosphatidylcholine And Nerve Growth Factor In A Rat Model Of Sciatic Nerve Regeneration After Crush Injury, Ryan L. Wood, Keaton S. Karlinsey, Austin D. Thompson, Mark N. Rigby, Greggory D. Boatright, William G. Pitt, Beverly L. Roeder, Scott C. Steffersen, Alonzo D. Cook

Faculty Publications

Schwann cells play a major role in helping heal injured nerves. They help clear debris, produce neurotrophins, upregulate neurotrophin receptors, and form bands of Büngner to guide the healing nerve. But nerves do not always produce enough neurotrophins and neurotrophin receptors to repair themselves. Nerve growth factor (NGF) is an important neurotrophin for promoting nerve healing and lysophosphatidylcholine (LPC) has been shown to stimulate NGF receptors (NGFR). This study tested the administration of a single intraneural injection of LPC (1 mg/mL for single LPC injection and 10 mg/mL for multiple LPC injections) at day 0 and one (day 7), two …

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Pedestrian Injury Severity Analysis In Motor Vehicle Crashes In Ohio, Majbah Uddin, Fahim Ahmed May 2018

Pedestrian Injury Severity Analysis In Motor Vehicle Crashes In Ohio, Majbah Uddin, Fahim Ahmed

Faculty Publications

According to the National Highway Traffic Safety Administration, 116 pedestrians were killed in motor vehicle crashes in Ohio in 2015. However, no study to date has analyzed crashes in Ohio in order to explore the factors contributing to the pedestrian injury severity resulting from motor vehicle crashes. This study fills this gap by investigating the crashes involving pedestrians exclusively in Ohio. This study uses the crash data from the Highway Safety Information System, from 2009 to 2013. The explanatory factors include the pedestrian, driver, vehicle, crash, and roadway characteristics. Both fixed- and random-parameters ordered probit models of injury severity (where …

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Second-Order Sensitivity Analysis Of Uncollided Particle Contributions To Radiation Detector Responses, Dan Gabriel Cacuci, Jeffrey A. Favorite May 2018

Second-Order Sensitivity Analysis Of Uncollided Particle Contributions To Radiation Detector Responses, Dan Gabriel Cacuci, Jeffrey A. Favorite

Faculty Publications

This work presents an application of Cacuci's Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) to the simplified Boltzmann equation that models the transport of uncollided particles through a medium to compute efficiently and exactly all of the first- and second-order derivatives (sensitivities) of a detector's response with respect to the system's isotopic number densities, microscopic cross sections, source emission rates, and detector response function. The off-the-shelf PARTISN multigroup discrete ordinates code is employed to solve the equations underlying the 2nd-ASAM. The accuracy of the results produced using PARTISN is verified by using the results of three test configurations: (1) a homogeneous …

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Superhydrophobic, Carbon-Infiltrated Carbon Nanotubes On Si And 316l Stainless Steel With Tunable Geometry, Kimberly A. Stevens, Christian D. Esplin, Taylor M. Davis, D. Jacob Butterfield, Philip S. Ng, Anton E. Bowden, Brian D. Jensen, Brian D. Iverson May 2018

Superhydrophobic, Carbon-Infiltrated Carbon Nanotubes On Si And 316l Stainless Steel With Tunable Geometry, Kimberly A. Stevens, Christian D. Esplin, Taylor M. Davis, D. Jacob Butterfield, Philip S. Ng, Anton E. Bowden, Brian D. Jensen, Brian D. Iverson

Faculty Publications

Use of carbon nanotubes to create superhydrophobic coatings has been considered due to their ability to offer a relatively uniform nanostructure. However, carbon nanotubes (CNTs) may be considered delicate with a typical diameter of tens of nanometers for a multi‐walled CNT; as‐grown carbon nanotubes often require the addition of a thin‐film hydrophobic coating to render them superhydrophobic. Furthermore, fine control over the diameter of the as‐grown CNTs, or overall nanostructure is difficult. This work demonstrates the utility of using carbon infiltration to layer amorphous carbon on multi‐walled nanotubes to improve structural integrity and achieve superhydrophobic behavior with tunable geometry. These …

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Marangoni Flows During Nonsolvent Induced Phase Separation, Douglas R. Tree, Tatsuhiro Iwama, Kris T. Delaney, Joshua Lee, Glenn H. Fredrickson Apr 2018

Marangoni Flows During Nonsolvent Induced Phase Separation, Douglas R. Tree, Tatsuhiro Iwama, Kris T. Delaney, Joshua Lee, Glenn H. Fredrickson

Faculty Publications

Motivated by the much discussed, yet unexplained, presence of macrovoids in polymer membranes, we explore the impact of Marangoni flows in the process of nonsolvent induced phase separation. Such flows have been hypothesized to be important to the formation of macrovoids, but little quantitative evidence has been produced to date. Using a recently developed multifluid phase field model, we find that roll cells indicative of a solutal Marangoni instability are manifest during solvent/nonsolvent exchange across a stable interface. However, these flows are weak and subsequently do not produce morphological features that might lead to macrovoid formation. By contrast, initial conditions …

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Nanoreactors: Strategies To Encapsulate Enzyme Biocatalysts In Virus-Like Particles, Joshua W. Wilkerson, Seung-Ook Yang, Parker J. Funk, Steven K. Stanley, Bradley Charles Bundy Apr 2018

Nanoreactors: Strategies To Encapsulate Enzyme Biocatalysts In Virus-Like Particles, Joshua W. Wilkerson, Seung-Ook Yang, Parker J. Funk, Steven K. Stanley, Bradley Charles Bundy

Faculty Publications

Enzyme-mediated biocatalysis is generally more selective and environmentally friendly and requires less energy than chemocatalysis. However, factors such as temperature, acidity and the presence of proteases can negate enzyme activity. Encapsulation in virus-like particles is one promising method to mitigate these difficulties. Encapsulation also can be used to create multi-reaction nanoreactors that increase process efficiency by isolating reaction intermediates. To successfully encapsulate enzymes, a variety of methods involving both non-covalent and covalent interactions have been developed. Here we review promising virus-like particle encapsulation strategies, their advantages and remaining challenges.

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Uncertainty Evaluation In The Design Of Structural Health Monitoring Systems For Damage Detection, Christine Schubert Kabban, Richard Uber, Kevin Lin, Bin Li, Md Yeasin Bhuiyan, Victor Giurgiutiu Apr 2018

Uncertainty Evaluation In The Design Of Structural Health Monitoring Systems For Damage Detection, Christine Schubert Kabban, Richard Uber, Kevin Lin, Bin Li, Md Yeasin Bhuiyan, Victor Giurgiutiu

Faculty Publications

The validation of structural health monitoring (SHM) systems for aircraft is complicated by the extent and number of factors that the SHM system must demonstrate for robust performance. Therefore, a time- and cost-efficient method for examining all of the sensitive factors must be conducted. In this paper, we demonstrate the utility of using the simulation modeling environment to determine the SHM sensitive factors that must be considered for subsequent experiments, in order to enable the SHM validation. We demonstrate this concept by examining the effect of SHM system configuration and flaw characteristics on the response of a signal from a …

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Uncertainty Evaluation In The Design Of Structural Health Monitoring Systems For Damage Detection, Christine M. Schubert Kabban, Richard P. Uber, Kevin J. Lin, Bin Lin, M. Bhuiyan, Victor Giurgiutiu Apr 2018

Uncertainty Evaluation In The Design Of Structural Health Monitoring Systems For Damage Detection, Christine M. Schubert Kabban, Richard P. Uber, Kevin J. Lin, Bin Lin, M. Bhuiyan, Victor Giurgiutiu

Faculty Publications

The validation of structural health monitoring (SHM) systems for aircraft is complicated by the extent and number of factors that the SHM system must demonstrate for robust performance. Therefore, a time- and cost-efficient method for examining all of the sensitive factors must be conducted. In this paper, we demonstrate the utility of using the simulation modeling environment to determine the SHM sensitive factors that must be considered for subsequent experiments, in order to enable the SHM validation. We demonstrate this concept by examining the effect of SHM system configuration and flaw characteristics on the response of a signal from a …

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A Route Less Traveled: Principals’ Perceptions Of Alternative Licensed Cte Teachers, Scott R. Bartholomew, Emma P. Bullock, Louis S. Nadelson Apr 2018

A Route Less Traveled: Principals’ Perceptions Of Alternative Licensed Cte Teachers, Scott R. Bartholomew, Emma P. Bullock, Louis S. Nadelson

Faculty Publications

The shortage of teachers prepared to teach career and technical education (CTE) courses, or willing to work in certain locations (e.g. inner city, rural), has motivated the desire to explore solutions such as alternative routes to teacher licensure (ARL). Most ARL programs bypass colleges of education and provide a different approach to preparing individuals to teach, leaving many to wonder about the quality and knowledge of these teachers. Specific areas, such as CTE, have seen a large influx of ARL teachers in recent years. We sought to determine school principals’ perceptions of ARL CTE teachers. We found principal support for …

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Likelihood And Cost Impact Of Engineering Change Requirements For Dod Contracts, James C. Ellis, Edward D. White, Jonathan D. Ritschel, Shawn M. Valentine, Brandon Lucas, Ian S. Cordell Apr 2018

Likelihood And Cost Impact Of Engineering Change Requirements For Dod Contracts, James C. Ellis, Edward D. White, Jonathan D. Ritschel, Shawn M. Valentine, Brandon Lucas, Ian S. Cordell

Faculty Publications

Purpose: There appears to be no empirical-based method in the literature for estimating if an engineering change proposal (ECP) will occur or the dollar amount incurred. This paper aims to present an empirically based approach to address this shortfall.
Design/Methodology/Approach: Using the cost assessment data enterprise database, 533 contracts were randomly selected via a stratified sampling plan to build two regression models: one to predict the likelihood of a contract experiencing an ECP and the other to determine the expected median per cent increase in baseline contract cost if an ECP was likely. Both models adopted a stepwise approach. A …

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Lyophilized Escherichia Coli-Based Cell-Free Systems For Robust, High-Density, Long-Term Storage, Mark Thomas Smith, Scott D. Berkheimer, Christopher J. Werner, Bradley Charles Bundy Apr 2018

Lyophilized Escherichia Coli-Based Cell-Free Systems For Robust, High-Density, Long-Term Storage, Mark Thomas Smith, Scott D. Berkheimer, Christopher J. Werner, Bradley Charles Bundy

Faculty Publications

Cell-free protein synthesis (CFPS) is a versatile tool for rapid recombinant protein production and engineering. One drawback of cell-free technology is the necessity to store the major components—cell extracts and energy systems—below freezing in bulky aqueous solutions. Here we describe simple methods for lyophilizing extracts and preparing powdered energy systems for CFPS. These techniques allow for high-density storage of cell-free systems that are more robust against temperature and bacterial degradation. Our methods have the potential to decrease storage expenses, allow for longer shelf-life of cell extracts at room temperature, and enable durable portable protein production technologies.

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Streamlined Extract Preparation For Escherichia Coli-Based Cell-Free Protein Synthesis By Sonication Or Bead Vortex Mixing, Prashanta Shrestha, Troy Michael Holland, Bradley Charles Bundy Apr 2018

Streamlined Extract Preparation For Escherichia Coli-Based Cell-Free Protein Synthesis By Sonication Or Bead Vortex Mixing, Prashanta Shrestha, Troy Michael Holland, Bradley Charles Bundy

Faculty Publications

Escherichia coli-based cell extract is a vital component of inexpensive and high-yielding cell-free protein synthesis reactions. However, effective preparation of E. coli cell extract is limited to high-pressure (French press-style or impinge-style) or bead mill homogenizers, which all require a significant capital investment. Here we report the viability of E. coli cell extract prepared using equipment that is both common to biotechnology laboratories and able to process small volume samples. Specifically, we assessed the low-capital-cost lysis techniques of: (i) sonication, (ii) bead vortex mixing, (iii) freeze-thaw cycling, and (iv) lysozyme …

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Characterization Of Mechanical Properties Of Battery Electrode Films From Acoustic Resonance Measurements, Kathryn L. Dallon, Jing Yao, Dean R. Wheeler, Brian Mazzeo Apr 2018

Characterization Of Mechanical Properties Of Battery Electrode Films From Acoustic Resonance Measurements, Kathryn L. Dallon, Jing Yao, Dean R. Wheeler, Brian Mazzeo

Faculty Publications

Measurements of the mechanical properties of lithium-ion battery electrode films can be used to quantify and improve manufacturing processes and to predict the mechanical and electrochemical performance of the battery. This paper demonstrates the use of acoustic resonances to distinguish among commercial-grade battery films with different active electrode materials, thicknesses, and densities. Resonances are excited in a clamped circular area of the film using a pulsed infrared laser, and responses are measured using an electret condenser microphone. A numerical model is used to quantify the sensitivity of resonances to changes in mechanical properties. When the numerical model is compared to …

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Social Recommendations For Personalized Fitness Assistance, Saumil Dharia, Magdalini Eirinaki, Vijesh Jain, Jvalant Patel, Iraklis Varlamis, Jainikkumar Vora, Rizen Yamauchi Apr 2018

Social Recommendations For Personalized Fitness Assistance, Saumil Dharia, Magdalini Eirinaki, Vijesh Jain, Jvalant Patel, Iraklis Varlamis, Jainikkumar Vora, Rizen Yamauchi

Faculty Publications

Wearable technology allows users to monitor their activity and pursue a healthy lifestyle through the use of embedded sensors. Such wearables usually connect to a mobile application that allows them to set their profile and keep track of their goals. However, due to the relatively “high maintenance” of such applications, where a significant amount of user feedback is expected, users who are very busy, or not as self-motivated, stop using them after a while. It has been shown that accountability improves commitment to an exercise routine. In this work, we present the PRO-Fit framework, a personalized fitness assistant aiming at …

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Maximizing Whole Watershed Storage Through Optimized Reservoir Reoperation And Managed Aquifer Recharge, Erfan Goharian, Robert Gailey, Stephen Maples, Samuel Sandoval-Solis, Graham Fogg Apr 2018

Maximizing Whole Watershed Storage Through Optimized Reservoir Reoperation And Managed Aquifer Recharge, Erfan Goharian, Robert Gailey, Stephen Maples, Samuel Sandoval-Solis, Graham Fogg

Faculty Publications

No abstract provided.

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Impact Of First-Year Initiatives On Retention Of Students: Are There Differences In Retention Of Students By Ethnicity And Gender?, Patricia Backer, Joseph Green, Bryan Matlen, Cindy Kato Apr 2018

Impact Of First-Year Initiatives On Retention Of Students: Are There Differences In Retention Of Students By Ethnicity And Gender?, Patricia Backer, Joseph Green, Bryan Matlen, Cindy Kato

Faculty Publications

Project Succeed is a campus-wide initiative funded by the U.S. Department of Education. Its focus is to improve the 5-year graduation and retention rates and close the achievement gap for Under-Represented Minorities (URMs) across all majors at San José State University (SJSU). In addition, SJSU has a high percent of first generation students. We have several thrusts under this project: block scheduling, Faculty/Staff Mentor program, expanding Peer Educators, developing a First Year Experience Program, and developing more student living learning communities. This project is in its fourth year and we have analyzed each project effort with respect to its impact …

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Integrated Free-Form Method For Aerostructural Optimization Of Wind Turbine Blades, Ryan Barrett, Andrew Ning Apr 2018

Integrated Free-Form Method For Aerostructural Optimization Of Wind Turbine Blades, Ryan Barrett, Andrew Ning

Faculty Publications

A typical approach to optimize wind turbine blades separates the airfoil shape design from the blade planform design. This approach is sequential, where the airfoils along the blade span are pre-selected or optimized and then held constant during the blade planform optimization. In contrast, integrated blade design optimizes the airfoils and the blade planform concurrently and thereby has the potential to reduce cost of energy (COE) more than sequential design. Nevertheless, sequential design is commonly performed because of the ease of precomputation, or the ability to compute the airfoil analyses prior to the blade optimization. This research compares two integrated …

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Case Study: Cooling Channels For Material Testing Applications Using Laser Powder Bed Fusion, Benjamin M. Doane, Ryan P. O'Hara, K. Liu, Carl R. Hartsfield Apr 2018

Case Study: Cooling Channels For Material Testing Applications Using Laser Powder Bed Fusion, Benjamin M. Doane, Ryan P. O'Hara, K. Liu, Carl R. Hartsfield

Faculty Publications

Additive Manufacturing continues to gain a reputation as a key technology that will have a major impact on all aspects of mechanical engineering. The United States Air Force’s (USAF) Air Force Institute of Technology (AFIT), based in Dayton, Ohio, has expanded its AM-focused education and R&D capabilities with the purchase of a Laser Powder Bed Fusion system from Germany’s Concept Laser.

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Quantification Of The Impact Of Photon Distinguishability On Measurement-Device- Independent Quantum Key Distribution, Garrett K. Simon, Blake K. Huff, William M. Meier, Logan O. Mailloux, Lee E. Harrell Apr 2018

Quantification Of The Impact Of Photon Distinguishability On Measurement-Device- Independent Quantum Key Distribution, Garrett K. Simon, Blake K. Huff, William M. Meier, Logan O. Mailloux, Lee E. Harrell

Faculty Publications

Measurement-Device-Independent Quantum Key Distribution (MDI-QKD) is a two-photon protocol devised to eliminate eavesdropping attacks that interrogate or control the detector in realized quantum key distribution systems. In MDI-QKD, the measurements are carried out by an untrusted third party, and the measurement results are announced openly. Knowledge or control of the measurement results gives the third party no information about the secret key. Error-free implementation of the MDI-QKD protocol requires the crypto-communicating parties, Alice and Bob, to independently prepare and transmit single photons that are physically indistinguishable, with the possible exception of their polarization states. In this paper, we apply the …

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Highly Efficient Electrochemical Reforming Of Ch4/Co2 In A Solid Oxide Electrolyser, Jinhai Lu, Changli Zhu, Changchang Pan, Wenlie Lin, John P. Lemmon, Fanglin Chen, Chunsen Li, Kui Xie Mar 2018

Highly Efficient Electrochemical Reforming Of Ch4/Co2 In A Solid Oxide Electrolyser, Jinhai Lu, Changli Zhu, Changchang Pan, Wenlie Lin, John P. Lemmon, Fanglin Chen, Chunsen Li, Kui Xie

Faculty Publications

Reforming CH4 into syngas using CO2 remains a fundamental challenge due to carbon deposition and nanocatalyst instability. We, for the first time, demonstrate highly efficient electrochemical reforming of CH4/CO2 to produce syngas in a solid oxide electrolyser with CO2 electrolysis in the cathode and CH4 oxidation in the anode. In situ exsolution of an anchored metal/oxide interface on perovskite electrode delivers remarkably enhanced coking resistance and catalyst stability. In situ Fourier transform infrared characterizations combined with first principle calculations disclose the interface activation of CO2 at a transition state between a CO …

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A Bayesian Network Based Adaptability Design Of Product Structures For Function Evolution, Shaobo Li, Yongming Wu, Yan-Xia Xu, Jie Hu, Jianjun Hu Mar 2018

A Bayesian Network Based Adaptability Design Of Product Structures For Function Evolution, Shaobo Li, Yongming Wu, Yan-Xia Xu, Jie Hu, Jianjun Hu

Faculty Publications

Structure adaptability design is critical for function evolution in product families, in which many structural and functional design factors are intertwined together with manufacturing cost, customer satisfaction, and final market sales. How to achieve a delicate balance among all of these factors to maximize the market performance of the product is too complicated to address based on traditional domain experts’ knowledge or some ad hoc heuristics. Here, we propose a quantitative product evolution design model that is based on Bayesian networks to model the dynamic relationship between customer needs and product structure design. In our model, all of the structural …

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Atomic Layer Deposition On Porous Materials: Problems With Conventional Approaches To Catalyst And Fuel Cell Electrode Preparation, Tzia Ming Onn, Rainer Küngas, Paolo Fornasiero, Kevin Huang, Raymond J. Gorte Mar 2018

Atomic Layer Deposition On Porous Materials: Problems With Conventional Approaches To Catalyst And Fuel Cell Electrode Preparation, Tzia Ming Onn, Rainer Küngas, Paolo Fornasiero, Kevin Huang, Raymond J. Gorte

Faculty Publications

Atomic layer deposition (ALD) offers exciting possibilities for controlling the structure and composition of surfaces on the atomic scale in heterogeneous catalysts and solid oxide fuel cell (SOFC) electrodes. However, while ALD procedures and equipment are well developed for applications involving flat surfaces, the conditions required for ALD in porous materials with a large surface area need to be very different. The materials (e.g., rare earths and other functional oxides) that are of interest for catalytic applications will also be different. For flat surfaces, rapid cycling, enabled by high carrier-gas flow rates, is necessary in order to rapidly grow thicker …

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Numerical Simulation Of Heat Transfer And Chemistry In The Wake Behind A Hypersonic Slender Body At Angle Of Attack, Matthew J. Satchell, Jeffrey M. Layng, Robert B. Greendyke Mar 2018

Numerical Simulation Of Heat Transfer And Chemistry In The Wake Behind A Hypersonic Slender Body At Angle Of Attack, Matthew J. Satchell, Jeffrey M. Layng, Robert B. Greendyke

Faculty Publications

The effect of thermal and chemical boundary conditions on the structure and chemical composition of the wake behind a 3D Mach 7 sphere-cone at an angle of attack of 5 degrees and an altitude of roughly 30,000 m is explored. A special emphasis is placed on determining the number density of chemical species which might lead to detection via the electromagnetic spectrum. The use of non-ablating cold-wall, adiabatic, and radiative equilibrium wall boundary conditions are used to simulate extremes in potential thermal protection system designs. Non-ablating, as well as an ablating boundary condition using the “steady-state ablation” assumption to compute …

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An Experimental Study On Static And Dynamic Strain Sensitivity Of Embeddable Smart Concrete Sensors Doped With Carbon Nanotubes For Shm Of Large Structures, Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A. Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini Mar 2018

An Experimental Study On Static And Dynamic Strain Sensitivity Of Embeddable Smart Concrete Sensors Doped With Carbon Nanotubes For Shm Of Large Structures, Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A. Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini

Faculty Publications

The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM) of reinforced concrete structures. These sensors are fabricated by doping cement-matrix mterials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs), and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation. Previous work by the authors was devoted to material fabrication, modeling and applications in SHM. In this paper, we investigate the …

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