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2011

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Articles 661 - 690 of 5801

Full-Text Articles in Engineering

Quantifying Mass Sediment Movement In Deer Creek Reservoir During Spring Runoff And Potential Water Quality Impacts, Colin Rodger Ricks Oct 2011

Quantifying Mass Sediment Movement In Deer Creek Reservoir During Spring Runoff And Potential Water Quality Impacts, Colin Rodger Ricks

Theses and Dissertations

The accurate prediction of water quality is essential for management of reservoirs used for drinking water supply. Since algae are a major source of taste and odor problems in drinking water, understanding and controlling algal growth and production is an important task. Deer Creek Reservoir supplies drinking water for over one million people in northern Utah and has been highly eutrophic in the past. Despite major reductions in external nutrient loading, including phosphorus, seasonal algal blooms in Deer Creek have not decreased to desired levels. Resuspension of sediment has been suggested as a potential source of internal nutrient loading for …


Numerical Assessment Of A Venting System With Multi-Chamber Mufflers By Ga Method, Min-Chie Chiu, Ying-Chun Chang Oct 2011

Numerical Assessment Of A Venting System With Multi-Chamber Mufflers By Ga Method, Min-Chie Chiu, Ying-Chun Chang

Journal of Marine Science and Technology–Taiwan

Recently, research on new techniques of single-chamber perforated silencers has been addressed. However, the research work on shape optimization of multi-chamber silencers within a compact volume is rare. Work on the maximal allowable back pressure of mufflers has also been neglected. Therefore, the main purpose of this paper is to analyze the sound transmission loss (STL) of a space-constrained multi-chamber muffler and to optimize the best design shape under a specified pressure drop. In this paper, both the generalized decoupling technique and plane wave theory used to solve the coupled acoustical problem of multi-chamber perforated mufflers are presented. The four-pole …


Enhanced Valence Force Field Model For The Lattice Properties Of Gallium Arsenide, Sebastian Steiger, Mehdi Salmani-Jelodar, Denis Areshkin, Abhijeet Paul, Tillmann Kubis, Michael Povolotskyi, Hong-Hyun Park, Gerhard Klimeck Oct 2011

Enhanced Valence Force Field Model For The Lattice Properties Of Gallium Arsenide, Sebastian Steiger, Mehdi Salmani-Jelodar, Denis Areshkin, Abhijeet Paul, Tillmann Kubis, Michael Povolotskyi, Hong-Hyun Park, Gerhard Klimeck

Birck and NCN Publications

An enhanced valence force field model for zinc-blende crystals is developed to provide a unified description of the isothermal static and dynamical lattice properties of gallium arsenide. The expression for the lattice energy includes a second-nearest-neighbor coplanar interaction term, the Coulomb interaction between partially charged ions, and anharmonicity corrections. General relations are derived between the microscopic force constants and the macroscopic elastic constants in zinc-blende crystals. Applying the model to gallium arsenide, parameter sets are presented that yield quantitative agreement with experimental results for the phonon dispersion, elastic constants, sound velocities, and Gru ̈neisen mode parameters.


Design, Fabrication, And Implementation Of A Wireless, Passive Implantable Pressure Sensor Based On Magnetic Higher-Order Harmonic Fields, Ee Lim Tan, Andrew Derouin, Brandon D. Pereles, Keat Ghee Ong Oct 2011

Design, Fabrication, And Implementation Of A Wireless, Passive Implantable Pressure Sensor Based On Magnetic Higher-Order Harmonic Fields, Ee Lim Tan, Andrew Derouin, Brandon D. Pereles, Keat Ghee Ong

Michigan Tech Publications, Part 1

A passive and wireless sensor was developed for monitoring pressure in vivo. Structurally, the pressure sensor, referred to as the magneto-harmonic pressure sensor, is an airtight chamber sealed with an elastic pressure membrane. A strip of magnetically-soft material is attached to the bottom of the chamber and a permanent magnet strip is embedded inside the membrane. Under the excitation of an externally applied AC magnetic field, the magnetically-soft strip produces a higher-order magnetic signature that can be remotely detected with an external receiving coil. As ambient pressure varies, the pressure membrane deflects, altering the separation distance between the magnetically-soft strip …


Advancing Solutions For An Earthcube Design. What Can Be Learned From The Cuahsi His Experience? An Earthcube Design Approaches Paper, David G. Tarboton, David Maidment, Ilya Zaslavsky, Jon Goodall, Dan Ames, Richard P. Hooper, Jeffery S. Horsburgh, Kimberly A. T. Schreuders, Ray Idaszak, Alva Couch Oct 2011

Advancing Solutions For An Earthcube Design. What Can Be Learned From The Cuahsi His Experience? An Earthcube Design Approaches Paper, David G. Tarboton, David Maidment, Ilya Zaslavsky, Jon Goodall, Dan Ames, Richard P. Hooper, Jeffery S. Horsburgh, Kimberly A. T. Schreuders, Ray Idaszak, Alva Couch

Civil and Environmental Engineering Faculty Publications

The EarthCube goal of creating an infrastructure for managing and integrating knowledge across all geosciences in an open, transparent and inclusive manner aligns well with the overarching goals for the work that has been done in CUAHSI on Hydrologic Information Systems. CUAHSI has taken some steps in this direction, but a lot remains to be done. This paper describes these steps and makes some suggestions for the path ahead.


Fuzzy Control For Input Constrained Passive Affine Takagi-Sugeno Fuzzy Models: An Application To Truck-Trailer System, Wen-Jer Chang, Cheung-Chieh Ku, Chien-Hsun Huang Oct 2011

Fuzzy Control For Input Constrained Passive Affine Takagi-Sugeno Fuzzy Models: An Application To Truck-Trailer System, Wen-Jer Chang, Cheung-Chieh Ku, Chien-Hsun Huang

Journal of Marine Science and Technology–Taiwan

This paper describes a design of fuzzy controller for the input constrained discrete nonlinear passive systems via affine Takagi-Sugeno (T-S) fuzzy models. The stability conditions are derived based on Lyapunov and passive theories for the closed-loop system. The fuzzy controller design is accomplished by using the concept of Parallel Distribution Compensation (PDC). According to the proposed fuzzy control approach, the controlled system can achieve passive property and the input constraint, simultaneously. The Iterative Linear Matrix Inequality (ILMI) algorithm is applied in this paper to find the feasible solutions for the proposed fuzzy controller design approach. At last, a numerical simulation …


Improving The Interoperability Of Earth Observations, Jeffery S. Horsburgh, David G. Tarboton Oct 2011

Improving The Interoperability Of Earth Observations, Jeffery S. Horsburgh, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

In the history of science, many significant advances have resulted from new measurements. Despite the growing volume and sophistication of scientific theorizing of the past several decades, the ultimate source of information in many scientific disciplines is field observations and measurements. What is emerging today is an era of new data collection in the context of larger scale hydrologic and environmental observatories and in response to calls from leaders in the scientific community for new observing systems (e.g., data networks, field observations, and field experiments) that recognize the spatial and temporal heterogeneity of earth processes. These new data collection efforts …


Optimal Design Of Trusses With Geometric Imperfections: Accounting For Global Instability, Mehdi Jalalpour, Takeru Igusa, James K. Guest Oct 2011

Optimal Design Of Trusses With Geometric Imperfections: Accounting For Global Instability, Mehdi Jalalpour, Takeru Igusa, James K. Guest

Civil and Environmental Engineering Faculty Publications

A topology optimization method is proposed for the design of trusses with random geometric imperfections due to fabrication errors. This method is a generalization of a previously developed perturbation approach to topology optimization under geometric uncertainties. The main novelty in the present paper is that the objective function includes the nonlinear effects of potential buckling due to misaligned structural members. Solutions are therefore dependent on the magnitude of applied loads and the direction of resulting internal member forces (whether they are compression or tension). Direct differentiation is used in the sensitivity analysis, and analytical expressions for the associated derivatives are …


Experimental Study On The Flow Characteristics For Wind Over A Two-Dimensional Upwind Slope Escarpment, Ben-Jue Tsai, Bao-Shi Shiau Oct 2011

Experimental Study On The Flow Characteristics For Wind Over A Two-Dimensional Upwind Slope Escarpment, Ben-Jue Tsai, Bao-Shi Shiau

Journal of Marine Science and Technology–Taiwan

In this present study, wind tunnel experiments were conducted to measure the flow and turbulence characteristics for wind over an upwind slope of 15° escarpment. The mean wind speed and turbulence statistics, such as turbulence intensity, Reynolds stress, and wind power spectrum are investigated. Results indicate that wind speed-up phenomenon (increase of speed) occurred significantly around the tip of the upwind slope. The turbulence intensity decreases gradually as the wind flows from the toe of upwind slope to the tip of upwind slope. The wind power spectra for several sites along the upwind slope and top surface of escarpment at …


Compressed Sensing Based Analytical Modeling For Through-Silicon-Via Pairs, Tao Wang, Jingook Kim, Jun Fan, Yiyu Shi Oct 2011

Compressed Sensing Based Analytical Modeling For Through-Silicon-Via Pairs, Tao Wang, Jingook Kim, Jun Fan, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Through-Silicon-Vias (TSVs) are the critical enabling technique for three-dimensional integrated circuits (3D ICs). While there are a few existing works in literature to model the electrical performance of TSVs, they are either for fixed geometry or in lack of accuracy. in this paper, we use compressed sensing technique to model the electrical performance of TSV pairs. Experimental results indicate that with an exceptionally small number of samples, our model has a maximum relative error of 3.94% compared with full-wave simulations over a wide range of geometry parameters and frequencies. © 2011 IEEE.


Analysis Of Unbalanced System Efficiency With A Positive Sequence Power Flow Program, Karl Stefanski, Badrul H. Chowdhury Oct 2011

Analysis Of Unbalanced System Efficiency With A Positive Sequence Power Flow Program, Karl Stefanski, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

Most existing power flow programs assume balanced loading where the positive sequence impedances are sufficient to use. However, a more accurate approach is often required due to the increasing penetration of single-phase distributed generation sources on distribution grids which tend to introduce large imbalances. the proposed method uses a positive sequence power flow algorithm where the inputs are modified to accurately simulate an unbalanced system. the algorithm is tested on the IEEE 4-bus system and the results compared with published results. the impact of the analysis on system efficiency calculations are shown for the 4-bus system as well as for …


Investment Payback Calculator For Distributed Generation Sources, Md Rasheduzzaman, Elizabeth Stahlman, Badrul H. Chowdhury Oct 2011

Investment Payback Calculator For Distributed Generation Sources, Md Rasheduzzaman, Elizabeth Stahlman, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

The development of a distributed generation payback calculator that can be used for different types of energy technologies such as small wind turbines, fuel cells, microturbines, solar PV and other technologies is presented. the payback calculator takes several inputs such as technology costs, expected life of the project, capacity factor, system size, customer type, and several other relevant parameters. from these inputs, the calculator computes several different outputs including the total energy produced within a year, the rate of return, total expenses, total cash flow, and the discounted payback period in years. the calculator is embedded into a website available …


Grid Frequency And Voltage Support Using Pv Systems With Energy Storage, Ravi Bhatt, Badrul H. Chowdhury Oct 2011

Grid Frequency And Voltage Support Using Pv Systems With Energy Storage, Ravi Bhatt, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

An optimized operating scheme for a utility connected community based photovoltaic (PV) system is described. the system can participate in grid ancillary services like frequency and voltage regulation functions based on the Smart Grid framework. the proposed model comprises of a PV plant with Li-ion batteries coupled to the grid with the help of a three-phase inverter. a two-way communication between the PV plant and the grid is assumed. the PV/storage plant provides constant updates on its current kW/kVar capability, and the grid transmits the demand for specific amounts of power and for specific lengths of time. the battery charging …


Three-Dimensional Polarization States Of Monochromatic Light Fields, R. M.A. Azzam Oct 2011

Three-Dimensional Polarization States Of Monochromatic Light Fields, R. M.A. Azzam

Electrical Engineering Faculty Publications

The 3×1 generalized Jones vectors (GJVs) [ExEyEz]t (t indicates the transpose) that describe the linear, circular, and elliptical polarization states of an arbitrary three-dimensional (3-D) monochromatic light field are determined in terms of the geometrical parameters of the 3-D vibration of the time-harmonic electric field. In three dimensions, there are as many distinct linear polarization states as there are points on the surface of a hemisphere, and the number of distinct 3-D circular polarization states equals that of all two-dimensional (2-D) polarization states on the Poincaré sphere, of which only two are circular states. The subset of 3-D polarization …


Using Low-Stakes Quizzing For Student Self-Evaluation Of Readiness For Exams, Kirsten A. Davis Oct 2011

Using Low-Stakes Quizzing For Student Self-Evaluation Of Readiness For Exams, Kirsten A. Davis

Construction Management Faculty Publications and Presentations

Introductory level courses in many Science, Technology, Engineering, and Math (STEM) disciplines require students to acquire an enormous new discipline-specific vocabulary in preparation for future courses. Students are often not prepared for the amount of self-directed studying they must do to be successful in these types of courses, particularly in their first year of college. To assist students in more accurately gauging their readiness for an exam, online low-stakes quizzes were implemented in a freshman level course, giving students an opportunity to practice their new language with minimal grade-related consequences. This quizzing strategy provides students an opportunity to self-assess their …


General Doolittle's Elephant, Hal Cope Oct 2011

General Doolittle's Elephant, Hal Cope

ERAU Prescott Aviation History Program

Gen Jimmy Doolittle is known for many things, but hunting elephants is probably not among them! Hear the life story of this remarkable aviator from another pilot and former big game hunter, Hal Cope.


A Novel Solid Oxide Redox Flow Battery For Grid Energy Storage, Nansheng Xu, Xue Li, Xuan Zhao, John B. Goodenough, Kevin Huang Oct 2011

A Novel Solid Oxide Redox Flow Battery For Grid Energy Storage, Nansheng Xu, Xue Li, Xuan Zhao, John B. Goodenough, Kevin Huang

Faculty Publications

In this work we report proof-of-concept of a novel redox flow battery consisting of a solid oxide electrochemical cell (SOEC) integrated with a redox-cycle unit. The charge/discharge characteristics were explicitly observed by operating between fuel cell and electrolysis modes of the SOEC along with “in-battery” generation and storage of H2 realized by an in situ closed-loop reversible steam-metal reaction in the redox-cycle unit. With Fe/FeO as the redox materials, the new storage battery can produce an energy capacity of 348 Wh/kg-Fe and round-trip efficiency of 91.5% over twenty stable charge/discharge cycles. This excellent performance combined with robustness, environmental friendliness …


The Santa Clara, 2024-10-11, Santa Clara University Oct 2011

The Santa Clara, 2024-10-11, Santa Clara University

The Santa Clara

No abstract provided.


Effects Of (Nh(4))(2)S Passivation On The Off-State Performance Of 3-Dimensional Ingaas Metal-Oxide-Semiconductor Field-Effect Transistors, J J Gu, A T. Neal, P D. Ye Oct 2011

Effects Of (Nh(4))(2)S Passivation On The Off-State Performance Of 3-Dimensional Ingaas Metal-Oxide-Semiconductor Field-Effect Transistors, J J Gu, A T. Neal, P D. Ye

Birck and NCN Publications

Planar and 3-dimensional (3D) buried-channel InGaAs metal-oxide-semiconductor field-effect transistors (MOSFETs) have been experimentally demonstrated at deep-submicron gate lengths. The effect of (NH(4))(2)S passivation with different concentrations (20%, 10%, or 5%) on the off-state performance of these devices has been systematically studied. 10% (Na(4))(2)S treatment is found to yield the optimized high-k/InP harrier layer interface property, resulting in a minimum subthreshold swing (SS) lower than 100 mV/dec. Moreover, the 3D device structure greatly improves the off-state performance and facilitates enhancement-mode operation. A scaling metrics study has been carried out for 10% (NH(4))(2)S treated 3D devices with gate lengths down to 100 …


Direct Numerical Simulation Of Hypersonic Turbulent Boundary Layers. Part 4. Effect Of High Enthalpy, L. (Lian) Duan, M. P. Martín Oct 2011

Direct Numerical Simulation Of Hypersonic Turbulent Boundary Layers. Part 4. Effect Of High Enthalpy, L. (Lian) Duan, M. P. Martín

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper we present direct numerical simulations (DNS) of hypersonic turbulent boundary layers to study high-enthalpy effects. We study high-and low-enthalpy conditions, which are representative of those in hypersonic flight and ground-based facilities, respectively. We find that high-enthalpy boundary layers closely resemble those at low enthalpy. Many of the scaling relations for low-enthalpy flows, such as van-Driest transformation for the mean velocity, Morkovin's scaling, and the modified strong Reynolds analogy hold or can be generalized for high-enthalpy flows by removing the calorically perfect-gas assumption. We propose a generalized form of the modified Crocco relation, which relates the mean temperature …


A Study Of Solder Joint Failure Criteria, Jianbiao Pan, Julie Silk Oct 2011

A Study Of Solder Joint Failure Criteria, Jianbiao Pan, Julie Silk

Industrial and Manufacturing Engineering

One of the challenges in an experimental study of solder joint reliability is to determine when cracks occur in a solder joint or when a solder joint fails. Cracks in a real solder joint are difficult to identify using an X-Ray system. Cross-sectioning and scanning electron microscopy (SEM) is a destructive method. A common non-destructive test method is to monitor resistance increase in a solder joint or a daisy-chain. However, no scientific research has been done in establishing the relationship between the crack area of an interconnection and the change in resistance of the interconnection. This paper proposes a method …


Dissemination Of Geological Information In Avoiding Geotechnical Risks Associated With Tunnel Construction: Lessons Learned From Deep Voids In Marble In Lower Manhattan, New York City, Nazrul I. Khandaker, Stanley Schleifer, Masud Ahmed, Leah Scott Oct 2011

Dissemination Of Geological Information In Avoiding Geotechnical Risks Associated With Tunnel Construction: Lessons Learned From Deep Voids In Marble In Lower Manhattan, New York City, Nazrul I. Khandaker, Stanley Schleifer, Masud Ahmed, Leah Scott

Publications and Research

Test boring associated with the recently accomplished City Water Tunnel # 3 in Manhattan, New York City revealed moderately to highly weathered marble with insoluble silicate residues composed mostly of phlogopite, chlorite, and tremolite. Apparent control on the weatherability of the marble was in response to original mineral constituents dominating this lithology. Encountered marble samples ranged between pure calcitic to mixed dolomitic/siliceous types. Fresh marble samples collected from adjacent boring locations revealed characteristic geochemical data: Lime (25-45%), Silica (4-7%), Alumina (1-3%), MgO (5-20%), and LOI (35-42%); compressive strength of unweathered marble varied between 2000-3000 Kg/cm2. Relict foliations with …


Ceas E-News 10.07.2011, College Of Engineering And Applied Sciences Oct 2011

Ceas E-News 10.07.2011, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Concrete Canoe & Steel Bridge, Engineering Expo, GMI Award, Alumni Excellence Academy, Faculty/Staff Awards


Synthesis, Structural, Optical And Mechanical Characterization Of Srb2O4 Nanorods, Rui Li, Lihong Bao, Xiaodong Li Oct 2011

Synthesis, Structural, Optical And Mechanical Characterization Of Srb2O4 Nanorods, Rui Li, Lihong Bao, Xiaodong Li

Faculty Publications

Single crystalline strontium borate (SrB2O4) nanorods were synthesized for the first time via a facile sol–gel route at low temperature. The SrB2O4 nanorods have a good crystalline nature with the growth direction along the [511] orientation and they are transparent from the ultraviolet to the visible regimes. Nanoscale three-point bending tests were performed directly on individual nanorods to probe their mechanical properties using an atomic force microscope. The elastic modulus of SrB2O4 nanorods was measured to be 158.2 ± 2.8 GPa, exhibiting a significant increase compared with other borate nanostructures …


Problem-Based Cooperative Learning, Karl A. Smith, Byron G. Garry Oct 2011

Problem-Based Cooperative Learning, Karl A. Smith, Byron G. Garry

ASEE Best Practice Series Presentations

No abstract provided.


Automated Flow Path Design Optimization Using Mesh Morphing, William Dennis Gough Oct 2011

Automated Flow Path Design Optimization Using Mesh Morphing, William Dennis Gough

Theses and Dissertations

The use of CAD models and CFD analysis has become an essential part of fluid flow design. To reduce the time spent determining a design, optimization frameworks have been implemented to automate the process. Mesh morphing has been implemented within these frameworks to further reduce the time needed. While optimization methods have been developed to optimize a fluid flow path, the optimum design needs to be recreated in a CAD model. A method has been developed which eliminates the need to recreate the optimal results in CAD. This is accomplished by using mesh morphing, CAD and CFD together in an …


Supported Monoethanolamine For Co2 Separation, Morris D. Argyle, Zhuoyan Sun, Maohong Fan Oct 2011

Supported Monoethanolamine For Co2 Separation, Morris D. Argyle, Zhuoyan Sun, Maohong Fan

Faculty Publications

An alternative method for using monoethanolamine (MEA) in CO2 separation is developed from the viewpoints of the MEA-CO2 reaction environment and the process of spent sorbent regeneration. The method could be used to considerably reduce energy consumption compared to conventional aqueous MEA processes. MEA-TiO2 (MT) CO2 sorbent is synthesized using pure MEA and a support material, TiO2. The performance of the MT sorbent on CO2 separation was investigated in tubular reactors under various experimental conditions. The effects of several major factors on CO2 sorption by the MT sorbent were investigated. The sorption capacity of the MT sorbent increased with MEA …


Technical Note: Friction Factor Diagrams For Pipe Flow, Jim Mcgovern Oct 2011

Technical Note: Friction Factor Diagrams For Pipe Flow, Jim Mcgovern

Articles

This technical note describes diagrams of friction factor for pipe flow that have been prepared using, mainly, the equations that Lewis Moody used to prepare his famous diagram in 1944. The preparation of the new diagrams was prompted by the need for vector graphics versions that could be used for teaching purposes and that could be distributed freely to students and others under a Creative Commons Attribution-Share-Alike license. Using a structure very similar to that of Moody's diagram, variants with the Darcy friction factor and the Fanning friction factor have been prepared. In addition, variants have been prepared that include …


Ethane, Ethyne And Carbon Monoxide Concentrations In The Upper Troposphere And Lower Stratosphere From Ace And Geos-Chem: A Comparison Study, G. González Abad, N. D.C. Allen, P. F. Bernath, C. D. Boone, S. D. Mcleod, G. L. Manney, G. C. Toon, C. Carouge, Y. Wang, Shiliang Wu, X Oct 2011

Ethane, Ethyne And Carbon Monoxide Concentrations In The Upper Troposphere And Lower Stratosphere From Ace And Geos-Chem: A Comparison Study, G. González Abad, N. D.C. Allen, P. F. Bernath, C. D. Boone, S. D. Mcleod, G. L. Manney, G. C. Toon, C. Carouge, Y. Wang, Shiliang Wu, X

Michigan Tech Publications, Part 1

Near global upper tropospheric concentrations of carbon monoxide (CO), ethane (C2H6) and ethyne (C2H2) from ACE (Atmospheric Chemistry Experiment) Fourier transform spectrometer on board the Canadian satellite SCISAT-1 are presented and compared with the output from the Chemical Transport Model (CTM) GEOS-Chem. The retrievals of ethane and ethyne from ACE have been improved for this paper by using new sets of microwindows compared with those for previous versions of ACE data. With the improved ethyne retrieval we have been able to produce a near global upper tropospheric distribution of C2H2 from space. Carbon monoxide, ethane and ethyne concentrations retrieved using …


Dataset For Investigating Computational Efficiency Of Alternative Arterial Offset Optimization Algorithms, Christopher M. Day, Darcy M. Bullock Oct 2011

Dataset For Investigating Computational Efficiency Of Alternative Arterial Offset Optimization Algorithms, Christopher M. Day, Darcy M. Bullock

JTRP Data Papers

No abstract provided.