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Multidimensional Optimal Droop Control For Dc Microgrids In Military Applications, Kaitlyn J. Bunker, Michael D. Cook, Wayne Weaver, Gordon Parker 2018 Michigan Technological University

Multidimensional Optimal Droop Control For Dc Microgrids In Military Applications, Kaitlyn J. Bunker, Michael D. Cook, Wayne Weaver, Gordon Parker

Michigan Tech Publications

Reliability is a key consideration when microgrid technology is implemented in military applications. Droop control provides a simple option without requiring communication between microgrid components, increasing the control system reliability. However, traditional droop control does not allow the microgrid to utilize much of the power available from a solar resource. This paper applies an optimal multidimensional droop control strategy for a solar resource connected in a microgrid at a military patrol base. Simulation and hardware-in-the-loop experiments of a sample microgrid show that much more power from the solar resource can be utilized, while maintaining the system’s bus voltage around ...


Photocatalytic Activity: Experimental Features To Report In Heterogeneous Photocatalysis, Md. Ariful Hoque, Marcelo I. Guzman 2018 University of Kentucky

Photocatalytic Activity: Experimental Features To Report In Heterogeneous Photocatalysis, Md. Ariful Hoque, Marcelo I. Guzman

Chemistry Faculty Publications

Heterogeneous photocatalysis is a prominent area of research with major applications in solar energy conversion, air pollution mitigation, and removal of contaminants from water. A large number of scientific papers related to the photocatalysis field and its environmental applications are published in different journals specializing in materials and nanomaterials. However, many problems exist in the conception of papers by authors unfamiliar with standard characterization methods of photocatalysts as well as with the procedures needed to determine photocatalytic activities based on the determination of “apparent quantum efficiencies” within a wavelength interval or “apparent quantum yields” in the case of using monochromatic ...


Hemodynamics And Pathology Of An Enlarging Abdominal Aortic Aneurysm Model In Rabbits, Hongmei Chen, Yonghua Bi, Siyeong Yu, Linxia Gu, Xiaoyan Zhu, Xinwei Han 2018 Zhengzhou University & Zhengzhou Central Hospital Affiliated to Zhengzhou University

Hemodynamics And Pathology Of An Enlarging Abdominal Aortic Aneurysm Model In Rabbits, Hongmei Chen, Yonghua Bi, Siyeong Yu, Linxia Gu, Xiaoyan Zhu, Xinwei Han

Mechanical & Materials Engineering Faculty Publications

Hemodynamics may play an essential role in the initiation and progression of abdominal aortic aneurysm (AAA). We aimed to study the mechanism of self-healing process by the changes of hemodynamics and pathology in an enlarging AAA in rabbits. Seventy-two rabbits were randomly divided into three groups. Rabbits underwent extrinsic coarctation and received a 10-minute elastase incubation in Group A and Group B. Absorbable suture used in Group A was terminated by balloon dilation at week 4. Diameter was measured after 1, 3, 5, and 15 weeks, computational fluid dynamics analysis was performed at week 3 and week 15. Rabbits were ...


Techniques To Stimulate And Interrogate Cell–Cell Adhesion Mechanics, Ruiguo Yang, Joshua A. Broussard, Kathleen J. Green, Horacio D. Espinosa 2018 University of Nebraska-Lincoln

Techniques To Stimulate And Interrogate Cell–Cell Adhesion Mechanics, Ruiguo Yang, Joshua A. Broussard, Kathleen J. Green, Horacio D. Espinosa

Mechanical & Materials Engineering Faculty Publications

Cell–cell adhesions maintain the mechanical integrity of multicellular tissues and have recently been found to act as mechanotransducers, translating mechanical cues into biochemical signals. Mechanotransduction studies have primarily focused on focal adhesions, sites of cell-substrate attachment. These studies leverage technical advances in devices and systems interfacing with living cells through cell–extracellular matrix adhesions. As reports of aberrant signal transduction originating from mutations in cell–cell adhesion molecules are being increasingly associated with disease states, growing attention is being paid to this intercellular signaling hub. Along with this renewed focus, new requirements arise for the interrogation and stimulation of ...


The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco 2018 University of Central Florida

The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco

Buenaventura "Ven" Basco

No abstract provided.


Solid-State Processing Approach To Enhance The Mechanical Properties Of Polypropylene, Sharon Lau, Srikanthan Ramesh, Iris V. Rivero, LaShanda Korley 2018 Iowa State University

Solid-State Processing Approach To Enhance The Mechanical Properties Of Polypropylene, Sharon Lau, Srikanthan Ramesh, Iris V. Rivero, Lashanda Korley

Sharon Lau

Agenda: Background; Research Problem; Methodology; Results and Discussion; Conclusions.


Method To Provide Meta-Stable Operation Of Dc Microgrid Comprising A Pulsed Load, David G. Wilson, Wayne Weaver, Rush D. Robinett III, Ronald Matthews, Steven F. Glover 2018 Michigan Technological University

Method To Provide Meta-Stable Operation Of Dc Microgrid Comprising A Pulsed Load, David G. Wilson, Wayne Weaver, Rush D. Robinett Iii, Ronald Matthews, Steven F. Glover

Michigan Tech Patents

A Hamiltonian surface shaping power flow control (HSSPFC) method is used to analyze the meta-stability and adjust pulsed power loads on a DC electric power distribution network. Pulsed power loads are nonlinear, time-variant systems that cause nonlinear limit-cycles. During the on periods of a pulsed load, the system can be in an unstable state and is damped back to stability during the off state of the load. Therefore, over the entire period of the pulse the system may only be assessed as meta-stable. As shown through simulation, HIL and hardware results, the HSSPFC method is more accurate than the other ...


Modeling Sulfate Attack In Modern Concrete For Building Sustainable And Resilient Infrastructure, Zachary Grasley 2018 Texas A&M University

Modeling Sulfate Attack In Modern Concrete For Building Sustainable And Resilient Infrastructure, Zachary Grasley

Publications

External sulfate attack is a complex phenomenon and is manifested in the form of large expansion, cracking, and spalling depending on the exposure solution and material constituent properties. Several models were developed in the past to demonstrate sulfate attack mechanisms that account for the diffusion of sulfate ions into the porous concrete and the successive deformation triggered by the chemical reaction and precipitation of expansive agents. However, none of these models accounts for the effect of the migration of solvent water from the low solute concentration solution to high solute concentration solution driven by the osmotic pressure. Osmotic pressure is ...


Current-Driven Production Of Vortex-Antivortex Pairs In Planar Josephson Junction Arrays And Phase Cracks In Long-Range Order, Francisco Estellés-Duart, Miguel Ortuño, Andrés M. Somoza, Valerii M. Vinokur, Alex Gurevich 2018 Old Dominion University

Current-Driven Production Of Vortex-Antivortex Pairs In Planar Josephson Junction Arrays And Phase Cracks In Long-Range Order, Francisco Estellés-Duart, Miguel Ortuño, Andrés M. Somoza, Valerii M. Vinokur, Alex Gurevich

Physics Faculty Publications

Proliferation of topological defects like vortices and dislocations plays a key role in the physics of systems with long-range order, particularly, superconductivity and superfluidity in thin films, plasticity of solids, and melting of atomic monolayers. Topological defects are characterized by their topological charge reflecting fundamental symmetries and conservation laws of the system. Conservation of topological charge manifests itself in extreme stability of static topological defects because destruction of a single defect requires overcoming a huge energy barrier proportional to the system size. However, the stability of driven topological defects remains largely unexplored. Here we address this issue and investigate numerically ...


A Solid-State Processing Approach To Enhance The Mechanical Performance Of Polyolefins, Sharon Lau, Srikanthan Ramesh, Iris V. Rivero, LaShanda Korley 2018 Iowa State University

A Solid-State Processing Approach To Enhance The Mechanical Performance Of Polyolefins, Sharon Lau, Srikanthan Ramesh, Iris V. Rivero, Lashanda Korley

Sharon Lau

This study aims to present and evaluate the use of solid-state processing for improving the mechanical properties of polyolefins. Isotactic polypropylene (i-PP) was selected to be studied due to its inferior mechanical properties in comparison to common plastics such as polyethylene (PET) and polyvinyl chloride (PVC). Recently, i-PP has garnered attention due to its attributes such as low-cost and recyclability. However, it requires additional processing to improve its mechanical performance. In this study, cryomilling was used to introduce various concentrations (0.2 - 1 wt. %) of diparamethyldibenzyldiene sorbitol (MDBS), as reinforcing agent, into the i-PP polymer. X-ray diffraction (XRD) and differential ...


Experimental Tests And Numerical Simulations For Failure Investigation On Corrugated Boxes Used On Household Appliance Packaging, Diego Fernandes Rodrigues, José Carlos Pereira 2018 Whirlpool Latin America

Experimental Tests And Numerical Simulations For Failure Investigation On Corrugated Boxes Used On Household Appliance Packaging, Diego Fernandes Rodrigues, José Carlos Pereira

Journal of Applied Packaging Research

Packages made of corrugated paper are fundamental to the protection, transportation and handling of the appliance product market. During the storage and sales stages of a product, the package must resist compressive loads in different directions beyond moderate impacts. In this context, the objective of this work is to develop and implement a post-processor that allows the simultaneous analysis of two of the most common failure modes of packages made of corrugated paper: failure due to tensile or compressive stress limit, and failure due to local buckling, when the buckling of the faces of the corrugated paper between two peaks ...


Nanoflower-Like Bi2moo6/Ag3po4 In Water Treatment, Xavier Morgan-Lange, Jaeyun Moon, Kaleab Ayalew 2018 University of Nevada, Las Vegas

Nanoflower-Like Bi2moo6/Ag3po4 In Water Treatment, Xavier Morgan-Lange, Jaeyun Moon, Kaleab Ayalew

McNair Poster Presentations

No abstract provided.


Post-Wrapping Behavior Of High-Performance Stretch Film, Jake Wyns, John Cook, Kyle Dunno 2018 Atlantic Packaging

Post-Wrapping Behavior Of High-Performance Stretch Film, Jake Wyns, John Cook, Kyle Dunno

Journal of Applied Packaging Research

Compressive force is the energy a stretch film exerts onto the corners of a unit load of product, this paper analyzes the effects of compressive force overtime after application to a unit load. Previous research has shown how storage conditions, pallet configurations, and storage duration affect the performance of various packaging materials, however, there is a lack of this type of study relating to stretch film and load unitization. This paper looks at trends in compressive force depending on whether a film is applied with negative or positive secondary stretch. When a load is stretch wrapped with negative secondary stretch ...


Microstructure Design Using Graphs, Pengfei Du, Adrian Zebrowski, Jaroslaw Zola, Baskar Ganapathysubramanian, Olga Wodo 2018 Iowa State University

Microstructure Design Using Graphs, Pengfei Du, Adrian Zebrowski, Jaroslaw Zola, Baskar Ganapathysubramanian, Olga Wodo

Mechanical Engineering Publications

Thin films with tailored microstructures are an emerging class of materials with applications such as battery electrodes, organic electronics, and biosensors. Such thin film devices typically exhibit a multi-phase microstructure that is confined, and show large anisotropy. Current approaches to microstructure design focus on optimizing bulk properties, by tuning features that are statistically averaged over a representative volume. Here, we report a tool for morphogenesis posed as a graph-based optimization problem that evolves microstructures recognizing confinement and anisotropy constraints. We illustrate the approach by designing optimized morphologies for photovoltaic applications, and evolve an initial morphology into an optimized morphology exhibiting ...


Electrospun Collagen Fibers For Tissue Regeneration Applications, Ying Li 2018 The University of Western Ontario

Electrospun Collagen Fibers For Tissue Regeneration Applications, Ying Li

Electronic Thesis and Dissertation Repository

Tissue engineering aims to regenerate damaged and deceased tissue by combining cells with scaffold made from an appropriate biomaterial and providing a conducive environment to guide cell growth and the formation or regeneration of new tissue or organ. While collagen, an important material of the extracellular matrix (ECM), is a natural choice as a scaffold biomaterial, the conducive environment can only be created by having the ability to control the geometry, organization, structural and mechanical properties of the scaffold. Moreover, degradability and degradation rate control of the scaffold has to be taken into consideration too. In this work, we aim ...


Synthesis Of Crumpled Graphene And Titanium Dioxide Based–Nanomaterials And The Application To Carbon Dioxide Photoreduction, Yao Nie 2018 Washington University in St. Louis

Synthesis Of Crumpled Graphene And Titanium Dioxide Based–Nanomaterials And The Application To Carbon Dioxide Photoreduction, Yao Nie

Engineering and Applied Science Theses & Dissertations

With the rapid development of the economy, increasing combustion of fossils fuels has caused an increase in the atmospheric carbon dioxide (CO2) level, and has led to global climate change. As a mitigation approach, CO2 capture and conversion (CCC) can not only capture CO2, but also convert it to useable products, such as hydrocarbon fuels. Photocatalytic reduction is an attractive CCC option that directly harnesses inexpensive and abundant solar energy. Titanium dioxide (TiO2) is a widely used semiconductor for photocatalysis, and graphene nanosheets are a promising material for use in fabricating graphene-TiO2 hybridized photocatalysts. To realize the application of these ...


Developing Strategies To Toughen Bio-Inspired Adhesives, Narelli P. Narciso, Samuel Lee Huntington, Jonathan J. Wilker 2018 Indiana University of Pennsylvania

Developing Strategies To Toughen Bio-Inspired Adhesives, Narelli P. Narciso, Samuel Lee Huntington, Jonathan J. Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Mussels and other marine creatures adhere very well in underwater environments, having the ability to withstand the force of the sea. These animals have inspired synthetic biomimetic adhesives for wet systems, presenting potential for biomedical applications. However, most current commercial adhesives tend to be brittle, not resisting repetitive movements. This study assesses toughening strategies to improve the mussel-inspired adhesives’ ductility while maintaining its strength. The strategies included altering the polymer’s chemical structure by changing the percentage of polyethylene glycol (PEG) in the molecule and by adding fillers, such as calcium carbonate, silica and nacre - a calcium carbonate compound found ...


Pnnl Dark Matter Bubble Chamber, Ryan Robinson 2018 STAR Program

Pnnl Dark Matter Bubble Chamber, Ryan Robinson

STAR (STEM Teacher and Researcher) Presentations

The Pacific Northwest National Laboratory (PNNL) prototype bubble chamber is intended to address issues encountered with the current PICO dark matter search detectors and improve the functionality of future experimental designs. The PNNL bubble chamber accomplishes this with a simplified interface between the hydraulic pressure controls and the target vessel and altering the standard chamber design such that it can be easily exchanged and replaced with vessels of various sizes and materials for testing purposes. The chamber itself is a glass vessel which houses perfluorobutane and holds the target fluid above room temperature and atmospheric pressure. The target fluid becomes ...


Ice Adhesion Analysis Of Severely Aged Pdms Rubbers, Theodore R. Woll 2018 University of Denver

Ice Adhesion Analysis Of Severely Aged Pdms Rubbers, Theodore R. Woll

Electronic Theses and Dissertations

The goal of this study was to evaluate and optimize the ice adhesion test initially developed by the University of Denver and to examine Polydimethylsiloxane (PDMS) based silicone rubbers for their ice-phobicity as a function of their physical and chemistry properties, and under severe oxidative aging. The test is based on an ice block bonded to a silicone rubber substrate and subjected to shear. In its original state, the test had severe limitations that caused the ice to be dislodged through a mixture of shear and peeling. Several steps were taken in this research to improve the test, and the ...


Aberration Corrected Analytical Electron Microscopy Studies Of Nanometallic Catalysts, Sultan Althahban 2018 Lehigh University

Aberration Corrected Analytical Electron Microscopy Studies Of Nanometallic Catalysts, Sultan Althahban

Theses and Dissertations

Catalysis by nanoscopic metal structures, ranging from nanoparticles to sub-nm clusters and even individual atoms, is amongst the most intensely studied topics in nanoscience. The catalytic performance of supported metal nanoparticles is governed by their crysallographic structure, shape, size, composition and interaction with the support. Aberration-corrected scanning transmission electron microscopy (AC-STEM), with its ultra-high spatial resolution for imaging and compositional analysis, is an ideal tool for characterizing such features in metallic nanocatalysts. In this thesis, five case studies are presented where AC-STEM has been invaluable in elucidating synthesis route - structure - performance relationships in some technologically important catalyst systems.


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