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Full-Text Articles in Engineering Science and Materials

Electromechanics Of An Ocean Current Turbine, Vasileios Tzelepis Dec 2015

Electromechanics Of An Ocean Current Turbine, Vasileios Tzelepis

University of New Orleans Theses and Dissertations

The development of a numeric simulation for predicting the performance of an Ocean Current Energy Conversion System is presented in this thesis along with a control system development using a PID controller for the achievement of specified rotational velocity set-points. In the beginning, this numeric model is implemented in MATLAB/Simulink® and it is used to predict the performance of a three phase squirrel single-cage type induction motor/generator in two different cases. The first case is a small 3 meter rotor diameter, 20 kW ocean current turbine with fixed pitch blades, and the second case a 20 meter, 720 ...


Umass Amherst Green Building Guidelines 2013, Ludmilla Pavlova-Gillham, Ted Mendoza, Ezra Small, Patricia O'Flaherty, Nariman Mostafavi, Mohamed Farzinmoghadam, Somayeh Tabatabaee Pozveh Oct 2015

Umass Amherst Green Building Guidelines 2013, Ludmilla Pavlova-Gillham, Ted Mendoza, Ezra Small, Patricia O'Flaherty, Nariman Mostafavi, Mohamed Farzinmoghadam, Somayeh Tabatabaee Pozveh

Ludmilla D Pavlova

Facilities & Campus Services, Sustainable UMass and Campus Planning support sustainability and energy conservation initiatives by providing in-house resources to campus staff as well as designers and contractors working with the University. The UMass Amherst Green Building Guidelines provide a framework for approaching new construction and major renovation projects at UMass Amherst that are undergoing LEED certification by focusing the conversation on green building aspects that are most important to the campus. They are intended to be the beginning of a dynamic conversation between designers, environmental consultants and constructors, university stakeholders, and users of new high performance buildings.


Structure And Optical Properties Of Transition Metal Dichalcogenides (Tmds) – Mx2 (M = Mo, W & X = S, Se) Under High Pressure And High Temperature Conditions, Nirup Reddy Bandaru Aug 2015

Structure And Optical Properties Of Transition Metal Dichalcogenides (Tmds) – Mx2 (M = Mo, W & X = S, Se) Under High Pressure And High Temperature Conditions, Nirup Reddy Bandaru

UNLV Theses, Dissertations, Professional Papers, and Capstones

Layered structured materials such as transition metal dichalcogenides (TMDs) have gained immense interest in recent times due to their exceptional structural, electrical and optical properties. Recent studies show semiconducting TMDs such as MX2 (M= Mo, W & X = S, Se) could be used as potential shock absorbing material, which has resulted in extensive studies on structural stability of these materials under the influence of high pressure. Understanding the structural stability of transition metal dichalcogenides (TMDs) such as MoS2, MoSe2, WS2, and WSe2 under high pressure has been very challenging due to contradicting observations and interpretations reported in the past. Hence ...


Thermal Vs. Photonic Sintering Of Nano Silver Based Conductive Inks, Bilge N. Altay, Paul D. Fleming May 2015

Thermal Vs. Photonic Sintering Of Nano Silver Based Conductive Inks, Bilge N. Altay, Paul D. Fleming

Bilge Nazli Altay

Conductive ink formulations with different electrical properties and their sintering methods after printing are an emerging area of interest. In this work, different line width and resolutions were printed on a a flexible PET substrate using a nano silver based conductive ink with gravure printing. Then printed traces were sintered with two different sintering methods and the results were compared.


Dynamic Simulation And Neuromuscular Control Of Movement: Applications For Predictive Simulations Of Balance Recovery, Misagh Mansouri Boroujeni May 2015

Dynamic Simulation And Neuromuscular Control Of Movement: Applications For Predictive Simulations Of Balance Recovery, Misagh Mansouri Boroujeni

Doctoral Dissertations

Balance is among the most challenging tasks for patients with movement disorders. Study and treatment of these disorders could greatly benefit from combined software tools that offer better insights into neuromuscular biomechanics, and predictive capabilities for optimal surgical and rehabilitation treatment planning. A platform was created to combine musculoskeletal modeling, closed-loop forward dynamic simulation, optimization techniques, and neuromuscular control system design. Spinal (stretch-reflex) and supraspinal (operational space task-based) controllers were developed to test simulation-based hypotheses related to balance recovery and movement control. A corrective procedure (rectus femoris transfer surgery) was targeted for children experiencing stiff-knee gait and how this procedure ...


Intensity And Resolution Enhancement Of Local Regions For Object Detection And Tracking In Wide Area Surveillance, Evan Krieger, Vijayan K. Asari, Saibabu Arigela, Theus H. Aspiras Apr 2015

Intensity And Resolution Enhancement Of Local Regions For Object Detection And Tracking In Wide Area Surveillance, Evan Krieger, Vijayan K. Asari, Saibabu Arigela, Theus H. Aspiras

Electrical and Computer Engineering Faculty Publications

Object tracking in wide area motion imagery is a complex problem that consists of object detection and target tracking over time. This challenge can be solved by human analysts who naturally have the ability to keep track of an object in a scene. A computer vision solution for object tracking has the potential to be a much faster and efficient solution. However, a computer vision solution faces certain challenges that do not affect a human analyst. To overcome these challenges, a tracking process is proposed that is inspired by the known advantages of a human analyst.

First, the focus of ...


Development Of A Metal-Printing 3d Printer At The University Of North Dakota, Benjamin Kading, Michaela Kegley, Tiana Delzer, Jeremy Straub, Scott Kerlin Mar 2015

Development Of A Metal-Printing 3d Printer At The University Of North Dakota, Benjamin Kading, Michaela Kegley, Tiana Delzer, Jeremy Straub, Scott Kerlin

Jeremy Straub

Three-dimensional (3D) printing is being used for numerous applications: from consumer hobbies to the development of aircraft parts. However, inexpensive 3D printers have been constrained in material selection to plastic. These printer use the fused deposition modeling (FDM) method of printing, which is a relatively new technology that utilizes computer numerical control (CNC) techniques to deposit melted material at specific places. Other methods, for example, include laser sintering and stereolithography. With 3D printing, layers are stacked upon each other and via this compilation of layers, a 3D object is formed. Currently there are a variety of materials that can be ...


Crystal-Amorphous Transformation Via Defect-Templating In Phase-Change Materials, Pavan Nukala Jan 2015

Crystal-Amorphous Transformation Via Defect-Templating In Phase-Change Materials, Pavan Nukala

Publicly Accessible Penn Dissertations

Phase-change materials (PCM) such as GeTe and Ge-Sb-Te alloys are potential candidates for non-volatile memory applications, because they can reversibly and rapidly transform between a crystalline phase and an amorphous phase with medium-range order. Traditionally, crystal-amorphous transformation in these materials has been carried out via melt-quench pathway, where the crystalline phase is heated beyond its melting point by the rising edge of an electric pulse, and the melt phase is quenched by the falling edge into a glassy phase. Formation of an intermediate melt phase in this transformation pathway requires usage of large switching current densities, resulting in energy wastage ...


Engineering Extracellular Matrix Signals Into Fibrous Hyaluronic Acid Hydrogels, Ryan Joseph Wade Jan 2015

Engineering Extracellular Matrix Signals Into Fibrous Hyaluronic Acid Hydrogels, Ryan Joseph Wade

Publicly Accessible Penn Dissertations

Hydrogels have gained widespread use in biomedical applications for their ability to mimic certain features of the natural extracellular matrix (ECM) including tissue-like mechanics, water-swollen environments, and biodegradability. Despite these advantages, hydrogels typically do not present the fibrous architecture of natural ECM, even though this structure can guide cell behavior and tissue function. With this in mind, the overall goal of this dissertation is the translation of hydrogels from hyaluronic acid (HA) macromers into more complex, fibrous networks with spatiotemporal control. First, HA macromers that contain protease-cleavable and fluorescent peptides were synthesized and shown to form both isotropic hydrogels and ...


Adaptive Structural Control Using Dynamic Hyperspace, Simon Laflamme Jan 2015

Adaptive Structural Control Using Dynamic Hyperspace, Simon Laflamme

Civil, Construction and Environmental Engineering Publications

The design of closed-loop structural control systems necessitates a certain level of robustness to cope with system uncertainties. Neurocontrollers, a type of adaptive control system, have been proposed to cope with those uncertainties. However, the performance of neural networks can be substantially influenced by the choice of the input space, or the hyperspace in which the representation lies. For instance, input selection may influence computation time, adaptation speed, effects of the curse of dimensionality, understanding of the representation, and model complexity. Input space selection is often overlooked in literature, and inputs are traditionally determined offline for an optimized performance of ...


Detection Of Sub-Surface Stresses In Ferromagnetic Materials Using A New Barkhausen Noise Method, Orfeas Kypris Jan 2015

Detection Of Sub-Surface Stresses In Ferromagnetic Materials Using A New Barkhausen Noise Method, Orfeas Kypris

Graduate Theses and Dissertations

In this work, a new, non-destructive method for obtaining stress-depth gradients in ferromagnetic structures was developed, using the information contained within magnetic Barkhausen emissions. A depth- and stress-dependent model for the frequency spectrum of Barkhausen emissions was derived and fitted to measured data obtained from steel samples with controlled stress-depth gradients. To achieve this, a library of signal processing and optimization algorithms was developed, which allowed the analysis of large datasets. To validate experimental procedures, a number of solid mechanics finite element simulations were carried out. Proof of concept is demonstrated by assuming linear stress-depth gradients and successfully calculating the ...


Supramolecular Assemblies Of Alkane Functionalized Poly Ethylene Glycol Copolymer For Drug Delivery, Lida Zhu Jan 2015

Supramolecular Assemblies Of Alkane Functionalized Poly Ethylene Glycol Copolymer For Drug Delivery, Lida Zhu

Graduate Theses and Dissertations

The therapeutic effects of many modern drugs were limited owing to their physical properties and half-life in the blood stream. The purpose of this research is to study the relationship between drug delivery performances and chemical properties of the polymer micelle drug carriers.

Polyethylene glycol (PEG) based alternating copolymer poly[(polyoxyethylene)-oxy-5-hydroxyisophthalic] (Ppeg) with PEG molecular weights of 600 and 1000 were synthesized and modified with different alkanes to study the effects of altering the hydrophobic and hydrophilic chain lengths. The nuclear magnetic resonance (NMR) spectrum, critical micelle concentration (CMC), micelle size, and micelle zeta potential of the synthesized polymers ...


The Effect Of Cell Contractility And Packing On Extracellular Matrix And Soft Tissue Rheology, Anne Sofieke Geertruide Van Oosten Jan 2015

The Effect Of Cell Contractility And Packing On Extracellular Matrix And Soft Tissue Rheology, Anne Sofieke Geertruide Van Oosten

Publicly Accessible Penn Dissertations

In the past decades it has become clear that the mechanical properties of tissues are important for healthy functioning. The mechanical properties of tissues and their load-bearing components found in the extracellular matrix (ECM) have been tested mechanically to provide more insight. However, there is a discrepancy between tissue and ECM mechanics. In this thesis this discrepancy is investigated with a novel multiaxial rheology method, which addresses a physiologically relevant combination of shear and axial strains. Blood clots are used to study the effect of cell traction and cell packing on ECM mechanics.

The results show that ECM networks compression ...


Ruo2 Nanorods As An Electrocatalyst For Proton Exchange Membrane Water Electrolysis, Richard Smith Jan 2015

Ruo2 Nanorods As An Electrocatalyst For Proton Exchange Membrane Water Electrolysis, Richard Smith

Graduate College Dissertations and Theses

The desire for pure diatomic hydrogen gas, H2(g), has been on the rise since the concept of the hydrogen economy system was proposed back in 1970. The production of hydrogen has been extensively examined over 40 + years as the need to replace current fuel sources, hydrocarbons, has become more prevalent. Currently there are only two practical and renewable production methods of hydrogen; landfill gas and power to gas. This study focuses on the later method; using various renewable energy sources, such as photovoltaics, to provide off-peak energy to perform water electrolysis. Efficient electrolysis takes place in electrochemical cells which ...