Engineering Commons^™

A Novel Data Pattern Dependent Electromagnetic Emission Modeling For High Speed Multi-Channel Interconnects, Nick K.H. Huang, Li (Lijun) Jun Jiang, Xingyun Luo, Huichun Yu, Huasheng Ren

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference (EMI) is becoming more serious when the data rate of the digital system continues increasing. However, its modeling and analysis are very challenging. In this paper, a novel electromagnetic superposition method is developed to model the electromagnetic emission for the high speed multi-channels on IC packagings. It employs the equivalence principle to obtain the electromagnetic field response over a broad spectrum. Then it uses the linear property of the passive parasitic system to superpose the contribution of different signal patterns. As a result, with limited pre-calculations, it is very convenient to compute the electromagnetic emission efficiently from different …

Development And Assessment Of A Groundwater Sustainability Index In Climatically Diverse Groundwater Irrigated Regions In Nebraska, Maria A. Mulet Jalil

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The aim of this research was to evaluate the impact of regional change in ET on groundwater level changes and the assessment and development of a groundwater sustainability index for climatically diverse regions across Nebraska during 2000-2014. Irrigation in the selected regions is predominantly supplied by groundwater. The hypothesis is that groundwater use can become sustainable if the regional evapotranspiration (ET) is managed so that it equals the ET of vegetation that is native to the region. Site locations were Box Butte, Chase, Dundy, Holt LNNRD and York Counties and 3 ecosystems were evaluated: native vegetation, dryland and irrigated cropping …

Heat Management Strategies For Msw Landfills, Nazli Yesiller, James L. Hanson, Kevin B. Kopp, Emma H. Yee

Civil and Environmental Engineering

Heat is a primary byproduct of landfilling of municipal solid waste. Long-term elevated temperatures have been reported for MSW landfills under different operational conditions and climatic regions around the world. A conceptual framework is presented for management of the heat generated in MSW landfills. Three main strategies are outlined: extraction, regulation, and supplementation. Heat extraction allows for beneficial use of the excess landfill heat as an alternative energy source. Two approaches are provided for the extraction strategy: extracting all of the excess heat above baseline equilibrium conditions in a landfill and extracting only a part of the excess heat above …

Prefrontal Responses To Stroop Tasks In Subjects With Post-Traumatic Stress Disorder Assessed By Functional Near Infrared Spectroscopy, Amarnath Yennu, Fenghua Tian, Alexa Smith-Osborne, Robert J. Gatchel, Fu Lye Woon, Hanli Liu

Bioengineering Faculty Publications - Archive

No abstract provided.

A New Model Reference Control Architecture: Stability, Performance, And Robustness, Gerardo De La Torre, Tansel Yucelen, Eric N. Johnson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, we develop a new model reference control architecture to effectively suppress system uncertainties and achieve a guaranteed transient and steady-state system performance. Unlike traditional robust control frameworks, only a parameterization of the system uncertainty given by unknown weights with known conservative bounds is needed to stabilize uncertain dynamical systems with predictable system performance. In addition, the proposed architecture's performance is not dependent on the level of conservatism of the bounds of system uncertainty. Following the same train of thought as adaptive controllers that modify a given reference system to improve system performance, the proposed method is inspired …

Blinking Phase-Change Nanocapsules Enable Background-Free Ultrasound Imaging, Alexander S. Hannah, Geoffrey P. Luke, Stanislav Y. Emelianov

Dartmouth Scholarship

Microbubbles are widely used as contrast agents to improve the diagnostic capability of conventional, highly speckled, low-contrast ultrasound imaging. However, while microbubbles can be used for molecular imaging, these agents are limited to the vascular space due to their large size (> 1 μm). Smaller microbubbles are desired but their ultrasound visualization is limited due to lower echogenicity or higher resonant frequencies. Here we present nanometer scale, phase changing, blinking nanocapsules (BLInCs), which can be repeatedly optically triggered to provide transient contrast and enable background-free ultrasound imaging. In response to irradiation by near-infrared laser pulses, the BLInCs undergo cycles of …

Determining The Power And Energy Capacity Of A Battery Energy Storage System Utilizing A Smoothing Feeder Profile To Accommodate High Photovoltaic Penetration On A Distribution Feeder, Osama Mohammed Abbas Aly Mansour

Dissertations and Theses

Electricity is a perishable commodity; once it is generated it needs to be consumed or stored. Electric energy storage provides both power and energy capacity. Power capacity applications reduce the need for generation, while energy capacity allows for energy consumption to be decoupled from generation. Previous research was done to develop an algorithm for determining the power (MW) and energy (MWh) capacities of a battery energy storage system (BESS) to mitigate the adverse impacts of high levels of photovoltaic (PV) generation. The algorithm used a flat feeder profile, and its performance was demonstrated on the equinoxes and solstices.

Managing feeder …

Controls On Turbulent Mixing In A Strongly Stratified And Sheared Tidal River Plume, Joseph T. Jurisa, Jonathan Nash, James N. Moum, Levi F. Kilcher

Civil and Environmental Engineering Faculty Publications and Presentations

Considerable effort has been made to parameterize turbulent kinetic energy (TKE) dissipation rate εand mixing in buoyant plumes and stratified shear flows. Here, a parameterization based on Kunze et al. is examined, which estimates ε as the amount of energy contained in an unstable shear layer (Ri < Ri_c) that must be dissipated to increase the Richardson number Ri = N²/S² to a critical value Ri_c within a turbulent decay time scale. Observations from the tidal Columbia River plume are used to quantitatively assess the relevant parameters controlling ε over a range of tidal …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• Georgia Engineering Foundation Scholarships

Design Of Ferroelectric Mems Energy Harvesting Devices, Noah T. Blach, Robert A. Lake, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

Waste heat is a widely available but little used source of power. Converting a thermal gradient into electricity is conventionally done using the Seebeck effect, but devices that use this effect are naturally inefficient. An alternate approach uses microelectromechanical systems (MEMS) to generate movement and time-varying temperature from a constant temperature gradient. Ferroelectric materials can harvest electricity from moving structures and temperature variations. This concept was realized using traditional silicon microprocessing techniques. A silicon on insulator (SOI) wafer was backside Deep Reactive Ion Etched (DRIE) to form a one mm² by 7 micron thick silicon/silicon dioxide membrane. Lead zirconate …

Engineered Surfaces To Control Secondary Electron Emission For Multipactor Suppression, James M. Sattler, Ronald A. Coutu Jr., Robert A. Lake, Tod V. Laurvick

Electrical and Computer Engineering Faculty Research and Publications

A significant problem for space-based systems is multipactor - an avalanche of electrons caused by repeated secondary electron emission (SEE). The consequences of multipactor range from altering the operation of radio frequency (RF) devices to permanent device damage. Existing efforts to suppress multipactor rely heavily on limiting power levels below a multipactor threshold [1]. This research applies surface micromachining techniques to create porous surfaces to control the secondary electron yield (SEY) of a material for multipactor suppression. Surface characteristics of interest include pore aspect ratio and density. A discussion is provided on the advantage of using electroplating (vice etching) to …

Standardized Testing Of Non-Standard Photovoltaic Pavement Surfaces, John H. Nussbaum, Robert A. Lake, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

Emerging photovoltaic products have expanded the applications for the technologies into markets previously unconsidered for what was thought to be a delicate electronic product. One company leading this effort, Solar Roadways, Incorporated, is producing pavement replacing photovoltaic systems and proposing their use in everything from sidewalks to runways. Current pavement testing methods cannot be applied to these non-homogenous structures to identify if they can support the required loads. However, the standards called out specifically for pavements may be able to be translated to these products and their non-homogenous structures and non-standard materials to identify if they are able to perform …

Design And Analysis Of Novel Ge-Gete Pn Junction For Photovoltaics, Andrew M. Jones, Ronald A. Coutu Jr., Robert A. Lake

Electrical and Computer Engineering Faculty Research and Publications

The continuing rise in demand for energy places a similarly increasing demand to improve power production methods and efficiency. In regards to solar power generation, one major limiting factor with existing photovoltaic (PV) systems is the management of heat produced and photon interactions with the PV device. Typical devices operate within the 300-1000 nm range of the solar spectrum, greatly limiting the range of photons used for power generation. Furthermore, since infrared light (

Enhancing The Thermal Performance Of Temporary Fabric Structures For The Advanced Energy Efficient Shelter System, Justin E. Eshleman, Robert A. Lake, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

The focus of this research is to characterize the thermal load on temporary fabric shelters deployed in the Middle East in order to establish realistic contract specification for the thermal performance of future shelters. Three different testing methods were utilized to evaluate shelter thermal performance. Small-scale tests allowed for economical comparisons of different shelter materials and configurations.

Electrostrictive Polymers For Mechanical-To-Electrical Energy Harvesting, William G. Kaval, Ronald A. Coutu Jr., Robert A. Lake

Electrical and Computer Engineering Faculty Research and Publications

Research of electrostrictive polymers has generated new opportunities for harvesting energy from the surrounding environment and converting it into usable electrical energy. Piezoelectric ceramic based devices have long been used in energy harvesting for converting mechanical motion to electrical energy. Nevertheless, those materials tend to be unsuitable for low-frequency mechanical excitations such as human movement. Since organic polymers are typically softer and more flexible, the translated electrical energy output is considerably higher under the same mechanical force. Currently, investigations in using electroactive polymers for energy harvesting, and mechanical-to-electrical energy conversion, are beginning to show potential for this application. In this …

Dango (Doings And Goings On) - Vol. 22 | Issue 10, Rusty Towell, Cecily Towell, Haley Stien, Aric Tate, Vicente Rojas, Caleb Hicks, Zhaojia Xi, Paul Carstens, Joshua Daniel Martinez, Reuben Byrd, Mike Daugherity, Donald Isenhower

DANGO: Doings and Goings On: Summer Research Newsletter, Department of Engineering and Physics

ACU department of Engineering and Physics Weekly Summer Research Newsletter

Fabrication Of Mems Electrostatically Actuated Switch, Mattias Herrfurth

Journal of the Microelectronic Engineering Conference

No abstract provided.

Exploring Civil Drone Accidents And Incidents To Help Prevent Potential Air Disasters, Graham Wild, John Murray, Glenn Baxter

Research outputs 2014 to 2021

A recent alleged “drone” collision with a British Airways Airbus A320 at Heathrow Airport highlighted the need to understand civil Remotely Piloted Aircraft Systems (RPAS) accidents and incidents (events). This understanding will facilitate improvements in safety by ensuring efforts are focused to reduce the greatest risks. One hundred and fifty two RPAS events were analyzed. The data was collected from a 10-year period (2006 to 2015). Results show that, in contrast to commercial air transportation (CAT), RPAS events have a significantly different distribution when categorized by occurrence type, phase of flight, and safety issue. Specifically, it was found that RPAS …

Guided Wave Based Crack Detection In The Rivet Hole Using Global Analytical With Local Fem Approach, Bhuiyan Yeasin Md, Yanfeng Shen, Victor Giurgiutiu

Faculty Publications

In this article, ultrasonic guided wave propagation and interaction with the rivet hole cracks has been formulated using closed-form analytical solution while the local damage interaction, scattering, and mode conversion have been obtained from finite element analysis. The rivet hole cracks (damage) in the plate structure gives rise to the non-axisymmetric scattering of Lamb wave, as well as shear horizontal (SH) wave, although the incident Lamb wave source (primary source) is axisymmetric. The damage in the plate acts as a non-axisymmetric secondary source of Lamb wave and SH wave. The scattering of Lamb and SH waves are captured using wave …

Expanding The Versatility Of Nano Assembled Capsules As Platform Of Potential High Payload Mri Contrast Agents, Annah Farashishiko

Dissertations and Theses

Magnetic resonance imaging (MRI) has become a powerful clinical modality in diagnostic medicine. It is non-invasive and offers high spatial and temporal resolution. The goal of molecular imaging is to reveal the pathophysiology underlying the observed anatomy and diagnose diseases. The detection of pathological biomarkers can lead to early recognition of diseases and improved monitoring for recurrence. Clinically available contrast agents are limited in their discrimination of contrast between tissues and they tend to have very high detection limits. Because biomarkers are very low in concentration there is a need for high payload deposition of contrast agent (CA) and targeted …

Enthalpy-Based System-Model For Pumped Two-Phase Cooling Systems, Leitao Chen, Fanghao Yang, Pritish R. Parida, Mark Schultz, Timothy Chainer

Publications

The development of embedded chip cooling for 2D and 3D integrated circuits using pumped dielectric refrigerant has gained recent attention due to the ability to manage high heat densities and compatibility with electronics. Recent studies have focused on in-situ thermal and hydrodynamic phenomena (e.g. boiling and bubble dynamics) of two-phase flow boiling at micro-scales. In this paper we focus on the two-phase cooling system design including the cooling capability, size and coefficient of performance (COP). In implementing a two-phase cooling, a system-level computational model for two-phase cooling systems becomes necessary. Therefore, a computationally manageable and accurate one dimensional (1D) system …

A Critical Review Of High Entropy Alloys (Heas) And Related Concepts, D.B. Miracle, O.N. Senkov

Beyond Nickel-Based Superalloys II

The field of high entropy alloys (HEAs) is barely 10 years old. It has stimulated new ideas and has inspired the exploration of the vast composition space. Here we give a critical review of this body of work, with the intent of summarizing key findings, uncovering major trends and providing guidance for future efforts. Based on detailed analysis, the following major results emerge. An intense focus is apparent on alloys based on first row transition metal elements. These efforts have discovered an extended, single-phase solid solution phase field and are exploring the extent and properties of this phase field. As …

Towards Nanoindentation At Application-Relevant Temperatures – A Study On Cmsx-4 Alloy And Amdry-386 Bond Coat, James Gibson, Sebastian Schröders, Christoffer Zehnder, Sandra Korte-Kerzel

Beyond Nickel-Based Superalloys II

With nickel-based superalloys reaching their fundamental limit in high-temperature applications, new alloys are required with improved mechanical properties. Small-scale mechanical testing – particularly nanoindentation – is of great benefit to alloy development, allowing hardness and modulus to be measured on small volumes of newly-developed materials.

We show that it is now possible to carry out such tests in vacuum up to 1000˚C, paving the way for candidate alloys and coatings to be tested at operation-relevant conditions. In this work, a <001> oriented single-crystal CMSX4 sample and a 200 µm Amdry-386 bond coat were tested using a modified MicroMaterials NanoTest indenter. 1 …

Financial Modelling And Analysis Of The Management Of Dredged Marine Sediments – Development Of A Decision Support Tool, Joseph R. Harrington, J. Murphy, M. Coleman, D. Jordan, G. Szacsuri

Publications

Objective

The management of dredged sediments is a major challenge for many ports and harbours who need to maintain navigable access. Sediment volumes produced may be significant and expensive to manage. This paper presents financial modelling and analysis for the management of dredged marine sediment using a financial model developed which has the potential to be used as decision support tool by stakeholders in the Sector including Ports, Engineering Consultancies and Regulators.

Data/Methodology

A decision support tool has been developed to assess the financial aspect of a range of management uses for dredged marine sediments for a range of different …

Uwrl Director Mac Mckee Named Friend Of Ucowr | College Of Engineering, Usu College Of Engineering

College of Engineering News

July 20, 2016 — Mac McKee, Utah Water Research Lab Director, was recently named a Friend of UCOWR at the Universities Council on Water Resources (UCOWR) Annual Conference awards ceremony held this year in PensacolaBeach, Florida. UCOWR recognizes no more than three individuals each year who have “made substantial contributions in time and effort toward the goals of UCOWR.” Mac held the office of UCOWR President twice and served on the board of directors for nearly a decade.

Self-Similar Random Process And Chaotic Behavior In Serrated Flow Of High Entropy Alloys, Shuying Chen, Liping Yu, Jingli Ren, Xie Xie, Xueping Li, Ying Xu, Guangfeng Zhao, Peizhen Li, Fuqian Yang, Yang Ren, Peter K. Liaw

Chemical and Materials Engineering Faculty Publications

The statistical and dynamic analyses of the serrated-flow behavior in the nanoindentation of a high-entropy alloy, Al_0.5CoCrCuFeNi, at various holding times and temperatures, are performed to reveal the hidden order associated with the seemingly-irregular intermittent flow. Two distinct types of dynamics are identified in the high-entropy alloy, which are based on the chaotic time-series, approximate entropy, fractal dimension, and Hurst exponent. The dynamic plastic behavior at both room temperature and 200 °C exhibits a positive Lyapunov exponent, suggesting that the underlying dynamics is chaotic. The fractal dimension of the indentation depth increases with the increase of temperature, and …

Γ/Γ' Co-Base Superalloys – New High Temperature Materials Beyond Ni-Base Superalloys?, Steffen Neumeier, Christopher H. Zenk, Lisa P. Freund, Mathias Göken

Beyond Nickel-Based Superalloys II

In 2006 a new L1₂ phase, Co₃(Al,W), was discovered in the Co-Al-W system which has led to the development of novel Co-base superalloys with g/g¢ microstructures similar to those of the well-established Ni-base superalloys. First investigations on simple ternary alloys could show that these Co-Al-W based alloys exhibit higher solidus temperatures and show less segregations after casting compared to typical Ni-base superalloys. This leads to the question whether this g/g¢ Co-base superalloys can be regarded as new class of high temperature materials that can compete with or even supersede established Ni-base superalloys.

In the first part of …

Microstructural Analysis And High Temperature Creep Of Mo-9si-8b Alloys With Al And Ge Additions, Peter Kellner, Rainer Völkl, Uwe Glatzel

Beyond Nickel-Based Superalloys II

Refractory metals and their alloys show potential for high temperature applications, due to the increased melting point and creep resistance. Spark plasma sintering technology as well as argon arc melting is used to prepare quaternary and quinternary Mo-9Si-8B-xAl-yGe (x is 0 or 2; y is 0 or 2) samples. Compositions are stated in at.%. All the compositions consist of a Mo solid solution (α-Mo) and two intermetallic phases: Mo₃Si (A15) and Mo₅SiB₂ (T₂). On the one hand, no zirconium is added to the alloys to avoid evaporation of MoO₃ due to the …

Enhanced Oxidation Resistance Of Ti-Rich Mo-Si-B Alloys By Pack-Cementation Process, Camelia Gombola, Daniel Schliephake, Martin Heilmaier, John H. Perepezko

Beyond Nickel-Based Superalloys II

To increase efficiency by higher combustion temperatures of aircraft engines and energy generation, new high temperature materials are inevitable. Mo-Si-B alloys for example satisfy several requirements such as good oxidation and creep resistance. Recently, novel Ti-rich Mo-Si-B alloys have shown an increased creep resistance compared to Ti-free Mo-Si-B alloys by the formation of Ti-silicide precipitates during processing. However, due to the formation of a duplex SiO₂ – TiO₂ oxide layer, where fast inwards diffusion of oxygen takes place, the oxidation resistance is poor.

In this study we show that oxidation resistance of Mo-Si-B-Ti alloys can be enhanced drastically …

Enhancing Mobile Cloud Computing Security Using Steganography, Hassan Reza, Madhuri Sonawane

Computer Science Faculty Publications

Cloud computing is an emerging and popular method of accessing shared and dynamically configurable resources via the computer network on demand. Cloud computing is excessively used by mobile applications to offload data over the network to the cloud. There are some security and privacy concerns using both mobile devices to offload data to the facilities provided by the cloud providers. One of the critical threats facing cloud users is the unauthorized access by the insiders (cloud administrators) or the justification of location where the cloud providers operating. Although, there exist variety of security mechanisms to prevent unauthorized access by unauthorized …