Engineering Commons^™

Room-Temperature Organic Ferromagnetism In The Crystalline Poly(3-Hexylthiophene): Phenyl-C61-Butyric Acid Methyl Ester Blend Film, Bin Yang, Zhengguo Xiao, Yongbo Yuan, Tanjore V. Jayaraman, Jeffrey E. Shield, Ralph Skomski, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Pronounced ferromagnetism was observed in a crystalline blend film of conjugated polymer poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) by using magnetic force microscopy measurements. A substantial room-temperature saturation magnetization of about 0.65 emu g−1 was measured by an alternating gradient field magnetometer. Multiple experimental evidences demonstrate the charge transfer from the P3HT to the PCBM and the formation of P3HT crystal domain are expected to be two critical factors for the originals of room-temperature organic ferromagnetism.

Multiplatform Analysis Seismic Evaluation Of A Non-Seismically Detailed Nonlinear Rc Structure Retrofitted With Magneto-Rheological Dampers, Eric R. Lovejoy

Master's Theses

In prior research, the MR damper's dynamic characteristics are typically modeled in the MATLAB/Simulink environment. Creating a structural model with nonlinear material properties, however, may be challenging in the MATLAB/Simulink environment without approximating the material behavior and neglecting effects such as P-∆ or panel zone behavior. More behaviorally accurate models of these structures can be produced using nonlinear finite element analysis tools such as Abaqus, OpenSees or ZuesNL. These analysis tools, however, are not traditionally used to model the complex nonlinear and controllable behavior of MR dampers, nor their associated control algorithms. One solution is to facilitate communication between these …

A New Look At Azimuthal Wave Propagation Constants Of An N-Layered Dielectric Coated Pec Cylinder, Jason V. Paul, Peter J. Collins, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

A method for determining the azimuthal wave propagation constants supported by an n-layered dielectric coated PEC cylinder is presented. The method, based on a Green's function described in , is designed to optimally handle layered cylinders where the number of layers is extremely large as might be encountered in structures designed using transformational optics. The method is also tractable for any stratification profile without the need for individual layer analysis. We implement a recently developed numerical method to calculate Bessel functions of complex order and argument. Our method is verified by comparison with previously published results. We also present new …

Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan

Dissertations and Theses

Organic aerosols have significant effects on human health, air quality and climate. Secondary organic aerosols (SOA) are produced by the oxidation of primary-volatile organic compounds (VOC). For example, α-pinene reacts with oxidants such as hydroxyl radical (OH), ozone (O₃), and nitrate radical (NO₃), accounting for a significant portion of total organic aerosol in the atmosphere. Experimental studies have shown that the oxidation process between α-pinene and ozone has the most significant impact in the formation of SOA (Hoffmann et al., 1997). Most of the models used to predict SOA formation, however, are limited in that they …

A Novel Approach To Detecting Breathing-Fatigue Cracks Based On Dynamic Characteristics, Guirong Yan, Alessandro De Stefano, Emiliano Matta, Ruoqiang Feng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

During the Service Life of Structures, Breathing-Fatigue Cracks May Occur in Structural Members Due to Dynamic Loadings Acting on Them. These Fatigue Cracks, If Undetected, Might Lead to a Catastrophic Failure of the Whole Structural System. Although a Number of Approaches Have Been Proposed to Detect Breathing-Fatigue Cracks, Some of Them Appear Rather Sophisticated or Expensive (Requiring Complicated Equipment), and Others Suffer from a Lack of Sensitivity. in This Study, a Simple and Efficient Approach to Detecting Breathing-Fatigue Cracks is Developed based on Dynamic Characteristics of Breathing Cracks. First, Considering that Breathing Cracks Introduce Bilinearity into Structures, a Simple System …

Experimental Determination Of Electron-Hole Pair Creation Energy In 4h-Sic Epitaxial Layer: An Absolute Calibration Approach, S. K. Chaudhuri, K. J. Zavalla, K. C. Mandal

Faculty Publications

No abstract provided.

Effect Of Friction Stir Processing On The Tensile And Fatigue Behavior Of A Cast A206 Alloy, R. Kapoor, K. Kandasamy, R. S. Mishra, J. A. Baumann, G. Grant

Materials Science and Engineering Faculty Research & Creative Works

The microstructure of cast Al alloy A206 was modified using friction stir processing (FSP) to eliminate porosity, break down intermetallic particles and refine the grains. The inference from differential scanning calorimetry is that the nugget region of the as-FSP material contained primarily GP zones. Uniaxial tensile tests and bending fatigue tests were carried out at room temperature on A206 alloy in the cast and T4 conditions and after FSP with different heat treatments - as-FSP, FSP and aging, and FSP with solutionizing and aging. These produced varied microstructures with combinations of pores, grain sizes, precipitate types and particle sizes. The …

Variations Of Biogeography-Based Optimization And Markov Analysis, Haiping Ma, Daniel J. Simon, Minrui Fei, Zhikun Xie

Electrical and Computer Engineering Faculty Publications

Biogeography-based optimization (BBO) is a new evolutionary algorithm that is inspired by biogeography. Previous work has shown that BBO is a competitive optimization algorithm, and it demonstrates good performance on various benchmark functions and real-world optimization problems. Motivated by biogeography theory and previous results, three variations of BBO migration are introduced in this paper. We refer to the original BBO algorithm as partial immigration-based BBO. The new BBO variations that we propose are called total immigration-based BBO, partial emigration-based BBO, and total emigration-based BBO. Their corresponding Markov chain models are also derived based on a previously-derived BBO Markov model. The …

Spectrum Regrowth For Ofdm-Based Lte And Wimax Systems, Bosi Chen

Dissertations and Theses

An abstract of the thesis of Bosi Chen for the Master of Science in Electrical and Computer Engineering presented Aug 1st, 2012. Title: Spectrum Regrowth for OFDM-based LTE and WiMAX Systems. In OFDM-based (Orthogonal Frequency Dimension Multiplexing) LTE (Long Term Evolution) and WiMAX (Worldwide Interoperability for Microwave Access) Systems, one of the critical components is the RF power amplifier. With current technologies, RF power amplifiers are not perfectly linear. The nonlinearity of an RF power amplifier is one of the main concerns in RF power amplifier design. The nonlinearity control is described by the out-of-band power emission levels, and the …

The Santa Clara, 2013-01-17, Santa Clara University

The Santa Clara

No abstract provided.

Resistance Factors For Ductile Frp-Reinforced Concrete Flexural Members, Bashar Behnam, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

To prevent damage caused by corroding reinforcement, fiber reinforced polymer (FRP) reinforcing bars have been used in place of steel in a relatively small but increasing number of structures in the civil infrastructure. A concern with the use of traditional FRP bars, however, is the resulting lack of ductility. This problem has been overcome with the development of a new generation of composite reinforcement, ductile hybrid FRP (DHFRP) bars. However, standards that address the design of DHFRP bars are unavailable, and appropriate resistance factors for the use of DHFRP reinforcement are unknown. In this study, a reliability analysis is conducted …

Red-Green-Blue Light Sensitivity Of Oxide Nanowire Transistors For Transparent Display Applications, Sumi Lee, Seongmin Kim, David B. Janes, M. Meyyappan, Sanghyun Ju

Birck and NCN Publications

In this study, the sensitivity of oxide nanowire transistors under red (R, 470 nm), green (G, 530 nm), and blue (B, 625 nm) light illumination was investigated. As the wavelength of light illuminating the nanowire channel region became shorter, a negative shift of threshold voltage, degradation of subthreshold slope, and increase of on-current were observed. This phenomenon can be explained in terms of photoinduced holes, creating interfacial traps between the gate dielectric and nanowire channel or reacting with oxygen ions on the surface of the nanowires. Thus, the attempt to minimize characteristic changes due to all RGB light sources was …

Edwards Afb And The Air Force Flight Test Center, Charlie Bock Col, Usaf, Ret.

ERAU Prescott Aviation History Program

Hear an exciting review of Air Force flight test activity over a long period of time by someone who was there!

Modeling Biofuel Expansion Effects On Land Use Change Dynamics, Ethan Warner, Daniel Inman, Benjamin Kunstman, Brian Bush, Laura Vimmerstedt, Steve Peterson

Dartmouth Scholarship

Increasing demand for crop-based biofuels, in addition to other human drivers of land use, induces direct and indirect land use changes (LUC). Our system dynamics tool is intended to complement existing LUC modeling approaches and to improve the understanding of global LUC drivers and dynamics by allowing examination of global LUC under diverse scenarios and varying model assumptions. We report on a small subset of such analyses. This model provides insights into the drivers and dynamic interactions of LUC (e.g., dietary choices and biofuel policy) and is not intended to assert improvement in numerical results relative to other works.

Demand …

Exploring The Mechanisms Of Dna Hybridization On A Surface, Terry J. Schmitt, J Brandon Rogers, Thomas A. Knotts Iv

Faculty Publications

DNA microarrays are a potentially disruptive technology in the medical field, but their use in such settings is limited by poor reliability. Microarrays work on the principle of hybridization and can only be as reliable as this process is robust, yet little is known at the molecular level about how the surface affects the hybridization process. This work uses advanced molecular simulation techniques and an experimentally parameterized coarse-grain model to determine the mechanism by which hybridization occurs on surfaces. The results show that hybridization proceeds through a mechanism where the untethered (target) strand often flips orientation. For evenly lengthed strands, …

Reliability Analysis Of Rc Beams Exposed To Fire, Christopher D. Eamon, Elin A. Jensen

Civil and Environmental Engineering Faculty Research Publications

A procedure for conducting reliability analysis of reinforced concrete beams subjected to a fire load is presented. This involves identifying relevant load combinations, specifying critical load and resistance random variables, and establishing a high-temperature performance model for beam capacity. Based on the procedure, an initial reliability analysis is conducted using currently available data. Significant load random variables are taken to be dead load, sustained live load, and fire temperature. Resistance is in terms of moment capacity, with random variables taken as steel yield strength, concrete compressive strength, placement of reinforcement, beam width, and thermal diffusivity. A semi-empirical model is used …

The Nucleus 2012-2013, Rrosalie A. Richards

Science Education Center

No abstract provided.

Interfacial Bonding And Electronic Structure Of Hfo2/Gasb Interfaces: A First-Principles Study, Ka Xiong, Wei-Hua Wang, Dmitry Zhernokletov, Santosh Kc, Roberto Longo, R. Wallace, Kyeongjae Cho

Faculty Publications

The interfacial bonding and electronic structure of HfO2/GaSb interfaces has been investigated through first principles calculations. The calculated electronic structures of these interfaces reveal that some O-rich interfaces are semiconducting interfaces without any gap states. In contrast, for the interfaces with lower interfacial O content, gap states appear in the GaSb band gap, close to the conduction band. The valence band offsets are found to vary from 2.2 eV to 3.6 eV, depending on the interfacial O content. Our results suggest that GaSb is a suitable material to form high quality interface with HfO2.

Scaffold For Bone And Tissue Repair In Mammals, D. E. Day, Steven B. Jung

Materials Science and Engineering Faculty Research & Creative Works

A mammalian tissue scaffold and method for making a tissue scaffold including a rigid scaffold body of biocompatible glass fibers bonded together and in special alignment to define open channels within the scaffold to allow fluid flow into and within the scaffold.

Source Reconstruction Method-Based Radiated Emission Characterization For Pcbs, Ping Li, Li Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A technique based on a source reconstruction method (SRM) is employed to reproduce the same electromagnetic radiated emissions from printed circuit boards (PCB). This equivalent source is composed of both the electric and magnetic currents that are represented by a set of Rao-Wilton-Glisson basis functions. Planar magnetic near field is served as the input information for the SRM. The equivalent source is inversely acquired through the conjugate gradient algorithm that minimizes the norm of the residue. Magnetic field integral equation is utilized to find out the unknown coefficients of the currents. This method is directly extended to model the emissions …

Improved Target Impedance For Power Distribution Network Design With Power Traces Based On Rigorous Transient Analysis In A Handheld Device, Jingook Kim, Yuzo Takita, Kenji Araki, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

The concept of target impedance can be significantly improved, based on the rigorous closed-form expressions for transient supply voltage ripple excited by an integrated circuit (IC) switching current, for the power distribution network (PDN) with power traces that is commonly used in handheld devices. A systematic procedure for developing the target impedance is formulated, which is then applied to the PDN design of a handheld product. From measurements of transient IC switching currents, PDN impedance, and supply voltage ripple, it is shown that the proposed target impedance successfully correlates the PDN impedance in the frequency domain with the transient supply …

Accurate 3-D Capacitance Of Parallel Plates From 2-D Analytical Superposition, Richard E. Matick, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

The two-conductor strip line is a classic transmission line structure which has been extensively studied and used in endless applications for decades. Unfortunately, the exact determination of the 3-D capacitance of this basic case is analytically intractable. It will be shown that accurate values of the total 3-D capacitance of a parallel plate capacitor with thin plates of any length, width, and separation can be determined from the superposition of the exact 2-D capacitance obtained from an analytic solution using elliptic integrals in a very simple manner. The accuracy is determined for a range of cases through a comparison of …

Implementation Of Quantum Logic Gates Using Polar Molecules In Pendular States, Jing Zhu, Sabre Kais, Qi Wei, Dudley Herschbach, Bretislav Friedrich

Birck and NCN Publications

No abstract provided.

Quantum Algorithm And Circuit Design Solving The Poisson Equation, Yudong Cao, Anargyros Papageorgiou, Iasonas Petras, Joseph Traub, Sabre Kais

Birck and NCN Publications

The Poisson equation occurs in many areas of science and engineering. Here we focus on its numerical solution for an equation in d dimensions. In particular we present a quantum algorithm and a scalable quantum circuit design which approximates the solution of the Poisson equation on a grid with error epsilon. We assume we are given a superposition of function evaluations of the right-hand side of the Poisson equation. The algorithm produces a quantum state encoding the solution. The number of quantum operations and the number of qubits used by the circuit is almost linear in d and polylog in …

Experimental Study Of Nanofiber Production Through Forcespinning, Simon Padron, Arturo Fuentes, Dumitru Caruntu, Karen Lozano

Mechanical Engineering Faculty Publications

A newly developed method of producing nanofibers, called forcespinning, has proven to be a viable alternative to mass produce nanofibers. Unlike electrospinning, the most common method currently being employed (which draws fibers through the use of electrostatic force), forcespinning utilizes centrifugal forces which allow for a host of new materials to be processed into nanofibers (given that electric fields are not required) while also providing a significant increase in yield and ease of production. This work presents a detailed explanation of the fiber formation process. The study is conducted using high speed photography to capture the jet initiation process at …

The Santa Clara, 2013-01-10, Santa Clara University

The Santa Clara

No abstract provided.

Surface Interactions On Glass Optics During Fabrication, Post Processing & Laser Operation, Tayyab Suratwala

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Glasses For Energy Storage: Advancing The Energy Density And Safety Of Batteries, Steve W. Martin

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Glass And Glass Ceramic For Nonlinear Optics: Fundamentals To Applications, T. Cardinal, E. Fargin, J. J, Videau, Y. Petit, G. Guery, M. Dussauze, F. Adamiertz, V. Rodriguez, L. Canioni, A.| Royon

Functional Glasses: Properties And Applications for Energy and Information

No abstract provided.

Porter, William Logan, 1842-1937 (Sc 567), Manuscripts & Folklife Archives

Manuscript Collection Finding Aids

Finding aid and scan (Click on "additional files" below) for Manuscripts Small Collection 567. Letter, 1 March 1935, from William Logan Porter, Glasgow, Barren County, Kentucky, to Cyrus Edwards, Horse Cave, Hart County, Kentucky, concerning historical matters, especially the route of the old Lexington and Nashville Road through Allen and Barren Counties.