Engineering Commons^™

Control Of The Nanoscale Crystallinity And Phase Separation In Polymer Solar Cells, Chih-Wei Chu, Hoichang Yang, Wei-Jen Hou, Jinsong Huang, Gang Li, Yang Yang

Department of Mechanical and Materials Engineering: Faculty Publications

Grazing-incidence x-ray diffraction and atomic force microscopy were performed on bulk heterojunction regioregular poly(3-hexylthiophene) (RR-P3HT) [6,6]-phenyl-C₇₁-butyric acid methyl esters spin-cast films with different film processing conditions to correlate the crystalline nanostructure of P3HT with the corresponding solar cell performance. The increase in long wavelength absorption for solvent annealed films is related to highly conjugated crystal structure of RR-P3HT phase-separated in the active layer. Upon thermal annealing, the solvent annealed 50-nm-thick device shows high solar cell performance with fill factor up to 73% and power conversion efficiency of 3.80%.

Time And Pitch Scale Modification: A Real-Time Framework And Tutorial, Dan Barry, David Dorran, Eugene Coyle

Conference papers

A framework is presented which is designed to address the issues related to the real-time implementation of time-scale and pitch scale modification algorithms. This framework can be used as the basis for the developments of applications which allow for a seamless real-time transition between continually varying time scale and pitch-scale parameters which arise as a result of manual or automatic intervention.

Efficient Uncertainty Quantification Applied To The Aeroelastic Analysis Of A Transonic Wing, Serhat Hosder, Robert W. Walters, Michael Balch

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The application of a Point-Collocation Non-Intrusive Polynomial Chaos method to the uncertainty quantification of a stochastic transonic aeroelastic wing problem has been demonstrated. The variation in the transient response of the first aeroelastic mode of a three-dimensional wing in transonic flow due to the uncertainty in free-stream Mach number and angle of attack was studied. A curve-fitting procedure was used to obtain time-independent parameterization of the transient aeroelastic responses. Among the uncertain parameters that characterize the time-dependent transients, the damping factor was chosen for uncertainty quantification, since this parameter can be thought as an indicator for flutter. Along with the …

Byzantium Beneath The Black Sea, Bridget Buxton, Robert Ballard, Michael Brennan, Dwight Coleman, Katy Croff, Christopher Roman, Dan Davis, Dennis Piechota, Sergiy Voronov

Graduate School of Oceanography Faculty Publications

This poster reports on the August 2007 Black Sea Expedition of the Institute for Archaeological Oceanography at the University of Rhode Island (IAO) and the Institute for Exploration (IFE), in collaboration with the Department of the Underwater Heritage of Ukraine. This year’s work marks a new phase in a multi-year (2000–2012) archaeological and oceanographic survey of the Black Sea. 2007 fieldwork focuses on two Byzantine shipwrecks. The 10th century C.E. shipwreck Chersonesos A (discovered in 2006) lies at 140 m depth in the suboxic zone off the Crimean peninsula. The ship carried a cargo of one-handled jars of a widely …

Preparation And Accreditation Of Level 7 Engineering Programmes, Mark Mcgrath

Conference Papers

Accreditation of 3^rd level educational programmes by a suitably recognised professional body is of particular relevance in relation to engineering. The completion of a sequence of modules which leads to the attainment of this professionally recognised award is viewed as integral to the undertaking. The engineering technology fields are developing and expanding rapidly and the third level sector must keep abreast of these changes. This is essential if the third level institutions wish to continue delivering programmes which produce graduates who can successfully complete the transition from 3rd. Level to the various engineering sectors.

This paper outlines various aspects …

Performance Comparison Of Pb(Zr0.52Ti0.48)O3-Only And Pb(Zr0.52Ti0.48)O3-On-Silicon Resonators, Hengky Chandrahalim, Sunil A. Bhave, Ronald G. Polcawich, Jeff Pulskamp, Dan Judy, Roger Kaul, Madan Dubey

Faculty Publications

This paper provides a quantitative comparison and explores the design space of lead zirconium titanate (PZT)–only and PZT-on-silicon length-extensional mode resonators for incorporation into radio frequency microelectromechanical system filters and oscillators. We experimentally measured the correlation of motional impedance (R_X) and quality factor (Q) with the resonators’ silicon layer thickness (t_Si). For identical lateral dimensions and PZT-layer thicknesses (t_PZT), the PZT-on-silicon resonator has higher resonant frequency (f_C), higher Q (5100 versus 140), lower R_X (51 Ω versus 205 Ω), and better linearity [third-order input intercept …

The Effect Of Stirring On The Morphology Of Birnessite Nanoparticles, Marcos A. Cheney, Pradip K. Bhowmik, Shingo Moriuchi, Mario Villabos, Shizhi Qian, Sang W. Joo

Mechanical & Aerospace Engineering Faculty Publications

The effect of mechanical stirring on the morphology of hexagonal layer- structure birnessite nanoparticles produced from decomposition of KMnO₄ in dilute aqueous H₂SO₄ is investigated, with characterization by X- ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high- resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), and N₂ adsorption (BET). Mechanical stirring during an initial stage of synthesis is shown to produce black birnessite containing nanofibers, whereas granular particulates of brown birnessite are produced without stirring. This is the first reduction synthesis of black birnessite nanoparticles with dendritic morphology without any use …

Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Mikhail Khenner

Mathematics Faculty Publications

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …

Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev

Mathematics Faculty Publications

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …

A New Method Of Synthesizing Black Birnessite Nanoparticles: From Brown To Black Birnessite With Nanostructures, Marcos A. Cheney, Pradip K. Bhowmik, Shizhi Qian, Sang W. Joo, Wensheng Hou, Joseph M. Okoh

Mechanical & Aerospace Engineering Faculty Publications

A new method for preparing black birnessite nanoparticles is introduced. The initial synthesis process resembles the classical McKenzie method of preparing brown birnessite except for slower cooling and closing the system from the ambient air. Subsequent process, including wet-aging at 7° C for 48 hours, overnight freezing, and lyophilization, is shown to convert the brown birnessite into black birnessite with complex nanomorphology with folded sheets and spirals. Characterization of the product is performed by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), and N(2) adsorption ( BET) techniques. Wet-aging and lyophilization times are …

Development And Validation Of A Dynamic Model Of The Maglev Transportation System At Old Dominion University, Ajinkya Deodhar, Sebastian Bawab, Aravind Hanasoge

Mechanical & Aerospace Engineering Faculty Publications

A dynamic model of the vehicle/guideway coupled with a controller is developed for the maglev demonstration system currently being developed at ODU, using the MAthematical DYnamic MOdeling software - MADYMO. The fundamental characteristics of the vehicle and guideway are obtained from detailed finite element analyses using MSC-NASTRAN. As a result, the vehicle is modeled in MADYMO as a 21- degree-of-freedom spring-mass-damper system. A three span concrete guideway is modeled using 3D solid Hex8 elements. The air gap is modeled as a penetration of the magnets into the guideway. Decentralized colocated PD controllers are used for controlling the penetration of each …

Deploying Mobile Pv Emergency Power System In A Disaster, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Disasters can be as destructive as Hurricane Katrina, leaving several hundred-thousand people homeless, or as minor as an afternoon thunderstorm that brings down local power lines to your home. After a disaster, utility services may be damaged or destroyed, leaving people without water, sanitation, communication and electricity. In response to a disaster, first responders are deployed with life supporting resources, such as water, food, and medical supplies. Energy resources are often lacking, making recovery efforts difficult in our high-tech world of cell phones, television, computers, refrigerators and many other electronic devices.

After a disaster, the long time tradition used to …

Using Show Homes (And Sponsorships) To Persuade Commissioning Relevancy And Factory Crafted High Performance Modular Homes, Florida Solar Energy Center, Stephanie Thomas-Rees

FSEC Energy Research Center®

The International Builders' Show (IBS) sponsored by the National Association of Home Builders is a venue attracting over 100,000 builders and building related professionals every year. The increased attendances each year improves the educational sessions, vendor participation and "live" home construction demonstrations. The "live" home demonstrations are a great opportunity to integrate high performance construction and commissioning strategies into the marketplace to validate and distinguish products and the show home builders. At this past year's IBS show in February, Palm Harbor Homes built the GenX home that included an installed and operational 4.08kWp photovoltaic system with inverter and back up …

Discussion And Analysis Of Missile Igc Design, Michael W. Dancer, S. N. Balakrishnan, Ernest J. Ohlmeyer

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Missile intercept systems used in the next generation missile defense system will require extremely accurate performance of all component systems. Such systems will need to guarantee successful intercept of highly maneuvering targets. as a result, such interceptor systems require much greater performance in its guidance, control, and estimation subsystems. in order to develop systems that meet the required accuracies, integrated guidance and control (IGC) systems are currently being studied. These IGC architectures infuse the guidance and control systems into a single framework thereby promoting natural synergy among the missile subsystems. Previous work in this area has relied on missile body-Based …

Micromachined Nanoporous Membranes For Blood Oxygenation Systems, Vijayakrishnan Ambravaneswaran, Susheil Uttamaraj, Zeynep Çelik-Butler, Robert C. Eberhart, Charles J. Chuong, Richard E. Billo, Michael A. Savitt

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Nanostructured membranes with precisely engineered nanopores were fabricated on a thin silicon nitride membrane, using a combination of bulk micromachining and focused-ion-beam drilling. These membranes are designed to preserve microscale blood channel dimensions, thereby permitting the red cell shape change that enhances gas exchange in the pulmonary capillary. The membranes were tested for their mechanical stability and the results were verified with finite element analysis. Initial studies have proven the membranes to be robust, and capable of withstanding pressures typically experienced in blood oxygenator channels. A novel MEMS-based blood oxygenation system employing the nanoporous membranes is also presented. The oxygenation …

Dedication To Pierre Lallemand On The Occasion Of His Retirement, Dominque D'Humieres, Manfred Krafczyk, Li-Shi Luo, Robert Rubinstein

Mathematics & Statistics Faculty Publications

The fourth international conference for mesoscopic methods in engineering and science (http://www.icmmes. org), held in Munich, Germany, 16–20 July 2007, was closed with a celebration honouring Dr Pierre Lallemand on the occasion of his retirement from the Centre National de la Recherche Scientifique (CNRS) after more than 40 years of service.