Engineering Commons^™

Ultra-Thin Super High Frequency Two-Port Aln Contour-Mode Resonators And Filters, Matteo Rinaldi, Chiara Zuniga, Chengjie Zuo, Gianluca Piazza

Matteo Rinaldi

This paper reports on the demonstration of a new class of ultra-thin (250 nm thick) Super High Frequency (SHF) AlN piezoelectric two-port resonators and filters. A thickness field excitation scheme was employed to excite a higher order contour extensional mode of vibration in an AlN nano plate (250 nm thick) above 3 GHz and synthesize a 1.96 GHz narrow-bandwidth channel-select filter. The devices of this work are able to operate over a frequency range from 1.9 to 3.5 GHz and are employed to synthesize the highest frequency MEMS filter based on electrically self-coupled AlN contour-mode resonators. Very narrow bandwidth (~ …

Power Handling And Related Frequency Scaling Advantages In Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Matteo Rinaldi, Gianluca Piazza

Matteo Rinaldi

This paper reports on the analytical modeling and experimental verification of the mechanically-limited power handling and nonlinearity in piezoelectric aluminum nitride (AlN) contour-mode resonators (CMR) having different electrode configurations (thickness field excitation, lateral field excitation, one-port and two-port configurations) and operating at different frequencies (177-3047 MHz). Despite its simplicity, the one-dimensional analytical model fits the experimental behavior of AlN CMRs in terms of power handling capabilities. The model and experiment also confirm the advantage of scaling (i.e. miniaturizing) the AlN CMRs to higher frequencies at which higher critical power density can be more easily attained up to values in excess …

Investing In Maine Research Infrastructure: Sustainable Forest Bioproducts, Michael Eckardt, Stephen Shaler, Hemant P. Pendse, Adriaan R. P. Van Heiningen, Robert G. Wagner

University of Maine Office of Research Administration: Grant Reports

The University of Maine, the University of Southern Maine, several baccalaureate institutions in the state, along with other federal, state and local public, private, and non-profit institutions will collaborate to create the Forest Bioproducts Research Institute (FBRI) at the University of Maine. The vision of the FBRI is to advance understanding about the scientific underpinnings, system behavior, and policy implications for the production of forest-based bioproducts that meet societal needs for materials, chemicals, and fuels in an economically and ecologically sustainable manner.

The research plans Integrate three themes. They are (1) forest sustainability modeling of life cycle assessment, (2) integrated …

Electrical Impedance Imaging Of Corrosion On A Partially Accessible 2-Dimensional Region, Court Hoang, Katherine Osenbach

Mathematical Sciences Technical Reports (MSTR)

In this paper we examine the inverse problem of determining the amount of corrosion on an inaccessible surface of a two-dimensional region. Using numerical methods, we develop an algorithm for approximating corrosion profile using measurements of electrical potential along the accessible portion of the region. We also evaluate the effect of error on the problem, address the issue of ill-posedness, and develop a method of regularization to correct for this error. An examination of solution uniqueness is also presented.

Investigating Solutions To Wind Washing Issues In 2-Story Florida Homes; Phase 1, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Wind washing has been identified as a potentially significant issue regarding energy, demand, comfort, and humidity in some two-story Florida homes. In its most common configuration, wind washing occurs when attic spaces over first-floor portions of the home abut the second story, and the floor cavity of the second story is open to that attic space. Wind blowing into attic vents can push hot attic air into the inter-story floor cavity, bypassing the typical thermal boundaries of the building and introducing considerable heat into the house. Wind washing can also occur when there is little or no attic involved, where …

Method Of Transferring Strained Semiconductor Structure, Michael Nastasi

Department of Mechanical and Materials Engineering: Faculty Publications

The transfer of strained semiconductor layers from one substrate to another substrate involves depositing a multilayer structure on a substrate having surface contaminants. An interface that includes the contaminants if formed in between the deposited layer and the substrate. Hydrogen atoms are introduced into the structure and allowed to diffuse to the interface. Afterward, the deposited multilayer structure is bonded to a second substrate and is separated away at the interface, which results in transferring a multilayer structure from one substrate at least one strained semiconductor layer and at least one strain-induced seed layer. The strain-induced seed layer can be …

Structural Identification Using A Low-Cost Search Method, James W. Fonda, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

An easily implementable and trainable damage detection method is proposed and implemented for a simple truss structure. The approach uses the iterative search identification method and is compatible with low-cost and low-power microcontroller hardware. This method employs pattern matching for a data set from a strain sensor array and predicts location (truss member) and severity (member cross sectional area) of damage. As a health monitoring approach, the method is not as robust or rigorous as more complex methods. However, it has modest processing requirements and can handle noisy signals. The work presents an algorithm applied to a truss structure, the …

Preparation And Hydrogen Absorption/Desorption Of Nanoporous Palladium Thin Films, Wen-Chung Li, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Nanoporous Pd (np-Pd) was prepared by co-sputtering Pd-Ni alloy films onto Si substrates, followed by chemical dealloying with sulfuric acid. X-ray diffractometry and chemical analysis were used to track the extent of dealloying. The np-Pd structure was changed from particle-like to sponge-like by diluting the sulfuric acid etchant. Using suitable precursor alloy composition and dealloying conditions, np-Pd films were prepared with uniform and open sponge-like structures, with interconnected ligaments and no cracks, yielding a large amount of surface area for reactions with hydrogen. Np-Pd films exhibited shorter response time for hydrogen absorption/desorption than dense Pd films, showing promise for hydrogen …

The Antimicrobial Triclocarban Stimulates Embryo Production In The Freshwater Mudsnail Potamopyrgus Antipodarum, Ben D. Giudice, Thomas M. Young

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Recent research has indicated that the antimicrobial chemical triclocarban (TCC) represents a new type of endocrine disruptor, amplifying the transcriptional activity of steroid hormones and their receptors while itself exhibiting little affinity for these receptors. The effects of TCC were studied in the freshwater mudsnail Potamopyrgus antipodarum. Specimens were exposed to concentrations ranging from 0.05 to 10.5 mg/L dissolved TCC and were removed and dissected, and embryos contained within the brood pouch were counted and classified as shelled or unshelled after two and four weeks of exposure. After four weeks, environmentally relevant TCC concentrations of 1.6 to 10.5 mg/L resulted …

Towards Real Energy Economics: Energy Policy Driven By Life-Cycle Carbon Emission, R. Kenny, C. Law, Joshua M. Pearce

Joshua M. Pearce

Thermal Conduction In Molecular Materials Using Coarse Grain Dynamics: Role Of Mass Diffusion And Quantum Corrections For Molecular Dynamics Simulations, Ya Zhou, Alejandro Strachan

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

We use a mesodynamical method, denoted dynamics with implicit degrees of freedom DID, to characterize thermal transport in a model molecular crystal below and above its melting temperature. DID represents groups of atoms molecules in this case using mesoparticles and the thermal role of the intramolecular degrees of freedom DoFs are described implicitly using their specific heat. We focus on the role of these intramolecular DoFs on thermal transport. We find that thermal conductivity is independent of intramolecular specific heat for solid samples and a linear relationship between the two quantities in liquid samples with the coefficient of proportionality being …

Modeling And Computer Simulation Of Fault Calculations For Transmission Lines, Dr. Adel A. Elbaset

Dr. Adel A. Elbaset

Calculation of transmission line faults has a fundamental importance in the fault detection, classification, and location determination of faults in transmission line. This paper presents a proposed computer program based on Matlab software to calculate all ten types of shunt faults that may occur in a transmission line. Various fault scenarios (fault types, fault locations and fault impedance) are considered in this paper. The inputs of the proposed program are line length, source voltage, positive, negative and zero sequence for source impedance, line charging, and transmission line impedance. The output of the algorithm is used to train an artificial intelligence …

Comparative Evaluation Of Pid Voltage Mode, Pi Current Mode, Fuzzy And Pwm Based Sliding Mode Control For Dc-Dc Converters, Omar Ellabban, Joeri Van Mierlo

Omar Ellabban

This paper presents a comparison between the application of four control techniques in DC-DC converters. PID voltage mode (PID-VM), PI current mode (PI-CM), fuzzy, and PWM based sliding mode (SM) controllers are applied to buck converter. The design procedures of controllers are reviewed. The dynamic performance of these controllers under star-up, steady state, input voltage variation, load current disturbances and EMI spectrum are presented and compared.

Stability Analysis Of A Unified Power Flow Controller, Omar H. Abdalla, Mohamed A. E. Ghazy, Lotfy M. Lotfy, Nermeen A. M. Hassan

Omar H. Abdalla

The paper concerns with stability analysis of a Unified Power Flow Controller (UPFC). A nonlinear model is described in the abc-reference frame and then transformed into the dq0-reference frame. The model includes shunt and series compensators of the UPFC. Stability analysis is presented first in a three-dimensional space of system parameters. A linearized model is obtained in state-space form to be used in small-signal stability studies. Effects of system parameters on stability are investigated using eigenvalue analysis. These include resistance, reactance, and modulation indices of the shunt and series components of the UPFC. Simulation results show that the stability of …

Alan Turing Se Fraye Un Chemin Jusqu'À La Place De L'Ordinateur, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

A brief statement on the significance, impact and future developments related to the work of computer pioneer Alan Turing, in conjunction with Turing Day, held to commemorate his 90th birthday.

*The article is in French

A Use Of Theory Of Constraints Thinking Processes For Improvements In The Merged Beams Experiment At Oak Ridge National Laboratory., Bryan Richard Gross

Electronic Theses and Dissertations

Thinking exercises used in the Theory of Constraints (TOC) were used to find and remove constraints at the Merged Beams Experiment at Oak Ridge National Laboratory. The goal of this project was to significantly reduce the amount of time used to take a certain type of measurement during an experimental cycle. After the TOC exercises were used, a basic plan for change was discovered. Preliminary data were taken to establish a baseline of performance from which changes were made. Post-Modification was analyzed showing the project was a success.

The overlying reasoning for this exercise was to prove successfully that continuous …

Underwood, John Cox, 1840-1913 (Sc 2125), Manuscripts & Folklife Archives

MSS Finding Aids

Finding aid and scan (Click on "Additional Files" below) for Manuscripts Small Collection 2125. Letter, 14 August 1876, from John Cox Underwood, Bowling Green, Kentucky to Thomas E. Moss, Kentucky State Attorney General, Frankfort, Kentucky, in which he relates information about the condition of the locks and dams on the Green and Barren Rivers.

Efficient Rotation Algorithms For Texture Evolution, Mark W. Esty

Theses and Dissertations

Texture evolution is a vital component of many computational tools that link structure, properties and processes of polycrystalline materials. By definition, this evolution process involves the manipulation, via rotation, of points in orientation space. The computational requirements of the current methods being used to rotate crystalline orientations are a significant limiting factor in the drive to merge the texture information of materials into the engineering design process. The goal of this research is to find and implement a practical rotation algorithm that can significantly decrease the computation time required to rotate macroscopic and microscopic crystallographic textures. Three possible algorithms are …

Graduate Education In Research Ethics For Scientists And Engineers: Final Report, Jorge Ferrer-Negron, William Frey, Efrain O'Neill-Carrillo, Didier Valdes, Carlos Rios-Valazquez

Ethics in Science and Engineering National Clearinghouse

No abstract provided.

Spectroscopicellipsometer And Polarmeter Systemis, John A. Woollam, Blaine D. Johs, Craig M. Herzinger, Ping He, Martin M. Liphardt, Galen L. Pfeiffer

Department of Electrical and Computer Engineering: Faculty Publications

A rotating compensator spectroscopic ellipsometer or polarimeter system having a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for Supporting a material system, an analyzer, a dispersive optics and a detector system which comprises a multiplicity of detector elements, the system being functionally present in an environmental control chamber and therefore suitable for application in wide spectral range, (for example, 130-1700 nm). Preferred compensator design involves a Substantially achromatic multiple element compensator systems wherein multiple total internal reflections enter retardance into an entered beam of electromagnetic radiation, and the elements thereof are oriented to minimize changes …

Production Of Iron Using Environmentally-Benign Renewable Or Recycled Reducing Agents, Timothy C. Eisele, Surendra Komar Kawatra

Michigan Tech Patents

To produce metallic iron from iron ore, a composition comprising a mass of material formed from a mixture of iron ore particles and particles of a reductant that is either a biomass material in particulate form or a plastic resinous material in particulate form is used. The reductant can also be a mixture of biomass material and resin in any proportions. The mass of material comprises at least one body having a shape adapted for smelting such as pellets, briquettes, pieces or lumps. The pellets have sufficient cohesion to maintain the shape into which they have been formed. The invention …

Design And Implementation Of Dstatcom For Fast Load Compensation Of Unbalanced Loads, Wei-Neng Chang, Kuan-Dih Yeh

Journal of Marine Science and Technology

This paper proposes a distribution level static synchronous compensator (DSTATCOM) for fast load compensation of unbalanced loads in electric power distribution systems. For fast response requirement, a new feedforward compensation scheme is derived and employed in the paper. First, the compensation scheme of the DSTATCOM is derived with the symmetrical components method. Then, computer simulation with the program Matlab/Simulink preliminarily verifies the effectiveness of the proposed DSTATCOM. Accordingly, a hardware prototype is built with a floating-point DSP TMS320C6711-based system. Use of a current-regulated PWM (CRPWM) inverter as the power stage of the DSTATCOM generates needed compensation currents for real-time load …

Simulation Model To Investigate Flexible Workload Management For Healthcare And Servicescape Environment, Michael Thorwarth, Paul Harper, Amr Arisha

Conference papers

High demand and poor staffing conditions cause avoidable pressure and stress among healthcare personnel which results in burnout symptoms and unplanned absenteeism which are hidden cost drivers. The work environment within an emergency department is commonly arranged in a flexible workload which is highly dynamic and complex for the outside observer. Using detailed simulation modeling within structured modeling methods, a comprehensive model to characterize the nurses' time utilization in such flexible dynamic workload environment was investigated. The results have been used to derive a generalized analytic expression that describes certain settings that lead to an instable queuing system with serious …

Applied Climate-Change Analysis: The Climate Wizard Tool, Evan H. Girvetz, Chris Zganjar, George T. Raber, Edwin P. Maurer, Peter Kareiva, Joshua J. Lawler

Civil, Environmental and Sustainable Engineering

Background: Although the message of ‘‘global climate change’’ is catalyzing international action, it is local and regional changes that directly affect people and ecosystems and are of immediate concern to scientists, managers, and policy makers. A major barrier preventing informed climate-change adaptation planning is the difficulty accessing, analyzing, and interpreting climate-change information. To address this problem, we developed a powerful, yet easy to use, web-based tool called Climate Wizard (http://ClimateWizard.org) that provides non-climate specialists with simple analyses and innovative graphical depictions for conveying how climate has and is projected to change within specific geographic areas throughout the world. Methodology/Principal Findings: …

The Construction Common Product Coding System And Auto Id Technology In Construction, Nai-Hsin Pan

Journal of Marine Science and Technology

Automatic data identification (Auto ID) technology such as bar code has grown rapidly in various industries. During the last couple of years, a small number of construction companies have also started to implement Auto ID technologies for a limited number of applications. The focus of these applications has primarily been limited to the internal operations of a few larger companies. One of the major barriers to adopt modern Auto ID technologies in the construction industry is the lack of Construction Common Product Code System (CCPCS). The main objective of this research is to investigate the problems created by inadequate CCPCS …

A Novel Stability Condition And Its Application To Ga-Based Fuzzy Control For Nonlinear Systems With Uncertainty, Po-Chen Chen, Cheng-Wu Chen, Wei-Ling Chiang, Ken Yeh

Journal of Marine Science and Technology

In this study, we strive to combine the advantages of fuzzy logic control (FLC), genetic algorithms (GA), H∞ tracking control schemes, smooth control and adaptive laws to design an adaptive fuzzy sliding model controller for the rapid and efficient stabilization of complex and nonlinear systems. First, we utilize a reference model and a fuzzy model (both involving FLC rules) to describe and well-approximate an uncertain, nonlinear plant. The FLC rules and the consequent parameter are decided on via GA. A boundary-layer function is introduced into these updated laws to cover modeling errors and to guarantee that the state errors converge …

Service Life Prediction Of Pier For The Existing Reinforced Concete Bridges In Chloride-Laden Environment, Ming-Te Liang, Ran Huang, Shen-An Feng, Chi-Jang Yeh

Journal of Marine Science and Technology

The prediction method of service life for bridge structures is played an important role of bridge management system. In this paper, the mathematical modeling was to study the servise life prediction of pier for existing reinforced concrete (RC) bridge exposed to chloride environment. The corrosion process has three stages, the initiation time (tc), the depassivation time (tp), and the corrosion (propagation) time (tcorr). The total service life of pier for the existing RC bridge can be expressed as t = tc + tp + tcorr. Many mathematical models were applied to predicting each value of the tc, tp, and tcorr. …

Dsp-Based Implementation Of A Real-Time Doa Estimator For Underwater Acoustic Sources, Sheng-Yun Hou, Shun-Hsyung Chang, Hsien-Sen Hung, Jiang-Yao Chen

Journal of Marine Science and Technology

Many direction-of-arrival (DOA) estimation algorithms for acoustic sources based on sensor array measurements have been well developed and verified via computer simulations and/or small-scale water trough experiments. However, these results are not in practical use because the testing scenarios may not reflect real underwater environments. In order to have a better understanding of DOA estimation in sea experiments, a prototype of DSP-based acoustic DOA estimator is designed and implemented. The prototype system is based on TMS320VC33 digital signal processor and is validated by both computer simulation and experiments performed on the shallow water of Bi-Sha fishery harbor located near the …

Cpt-Based Simplified Liquefaction Assessment By Using Fuzzy-Neural Network, Shuh-Gi Chern, Ching-Yinn Lee

Journal of Marine Science and Technology

Due to the difficulty and the cost of obtaining high quality undisturbed samples, simplified methods based on in-situ tests such as the standard penetration test (SPT) and the cone penetration test (CPT) are preferred by geotechnical engineers for evaluation of earthquake induced liquefaction potential of soils. Because of the increasing popularity worldwide of the CPT for site characterization, significant progress on the CPTbased methods has been made. In most existing CPT-based methods, empirically determined curves are used to predict liquefaction and non-liquefaction. These empirical curves are generally relied on engineering judgment and are essentially performance functions that were established based …

Fundamental Properties Of Linear Ship Steering Dynamic Models, Ching-Yaw Tzeng, Ju-Fen Chen

Journal of Marine Science and Technology

This paper is concerned with the fundamental properties associated with the Nomoto models. Specifically, the state space model associated with the first order Nomoto model is both observable and controllable. The state space model associated with the second order Nomoto model is also observable; however, it is controllable only if the effective sway time constant is different from the effective yaw time constant. The zero appearing in the transfer function model is found responsible for the overshoot behaviors, which are typical in the yaw rate for large rudder angle steering. This suggests that a second order Nomoto model is more …