Electrostatically Tunable Meta-Atoms Integrated With In Situ Fabricated Mems Cantilever Beam Arrays, Ronald A. Coutu Jr., Peter J. Collins, Elizabeth A. Moore, Derrick Langley, Matthew E. Jussaume, Lavern A. Starman

Electrical and Computer Engineering Faculty Research and Publications

Two concentric split ring resonators (SRRs) or meta-atoms designed to have a resonant frequency of 14 GHz are integrated with microelectromechanical systems cantilever arrays to enable electrostatic tuning of the resonant frequency. The entire structure was fabricated monolithically to improve scalability and minimize losses from externally wire-bonded components. A cantilever array was fabricated in the gap of both the inner and outer SRRs and consisted of five evenly spaced beams with lengths ranging from 300 to 400 μm. The cantilevers pulled in between 15 and 24 V depending on the beam geometry. Each pulled-in beam increased the SRR gap capacitance …

Domestic Application Of Micro Wind Turbines In Ireland: Investigation Of Their Economic Viability, Zhe Li, Fergal Boyle, Anthony Reynolds

Articles

Electricity generation from renewable sources of energy will be a key part in the development of future strategies for many countries globally. This renewable electricity generation will be hugely important for Ireland, due to its lack of fossil fuel resources. The extremely good wind resource available provides Ireland with the opportunity of generating vast amount of electricity from wind energy. Large-scale wind electricity generation reached 1264 MW installed capacity by January 2010 in Ireland. However, micro scale wind electricity generation has not been very popular in Ireland to-date. The unclear economics of micro wind turbines, under Irish conditions, is considered …

The Irrigation Sector Shift From Construction To Modernization: What Is Required For Success?, Charles M. Burt

BioResource and Agricultural Engineering

External pressures related to environmental protection, commodity prices, energy availability, larger populations, and climate change have combined to require an immediate and substantial improvement in agricultural irrigation performance. Worldwide progression towards modernized irrigation projects has been uneven and slower than desired, but decades of irrigation modernization development have clarified certain requirements for success, as well as illuminated indicators of project failure. Of particular importance are required shifts within the state and national irrigation bureaucracies, as well as universities.

Investigating The Effects Of Learning Speeds On Xpilot Agent Evolution, Gary Parker, Phil Fritzsche

Computer Science Faculty Publications

In this paper we present a comparison of the effects of varying play speeds on a genetic algorithm in the space combat game Xpilot. Xpilot-AI, an Xpilot add-on designed for testing learning systems, is used to evolve the controller for an Xpilot combat agent at varying frames per second to determine an optimal speed for learning. The controller is a rule-based system modified to work with a genetic algorithm that learns numeric parameters for the agent’s rule base. The goal of this research is to increase the quality and speed of standard learning algorithms in Xpilot as well as determine …

Fitness Biasing For The Box Pushing Task, Gary Parker, Jim O'Connor

Computer Science Faculty Publications

Anytime Learning with Fitness Biasing has been shown in previous works to be an effective tool for evolving hexapod gaits. In this paper, we present the use of Anytime Learning with Fitness Biasing to evolve the controller for a robot learning the box pushing task. The robot that was built for this task, was measured to create an accurate model. The model was used in simulation to test the effectiveness of Anytime Learning with Fitness Biasing for the box pushing task. This work is the first step in new research where an automated system to test the viability of Fitness …

Using Cyclic Genetic Algorithms To Learn Gaits For An Actual Quadruped Robot, Gary Parker, William T. Tarimo

Computer Science Faculty Publications

It is a difficult task to generate optimal walking gaits for mobile legged robots. Generating and coordinating an optimal gait involves continually repeating a series of actions in order to create a sustained movement. In this work, we present the use of a Cyclic Genetic Algorithm (CGA) to learn near optimal gaits for an actual quadruped servo-robot with three degrees of movement per leg. This robot was used to create a simulation model of the movement and states of the robot which included the robot’s unique features and capabilities. The CGA used this model to learn gaits that were optimized …

Acuta Enews October 2011, Vol 40, No. 10

ACUTA Newsletters

ln This lssue

Nominate Now for 2012-2013 Board of Directors

Corinne Hoch Named Executive Director

Define Your Expectations to Vendors ......Ron Walczak, Walczak Technology Consultants

Additional Guidance on Taxation of Employer-Provided Cell Phones.......Michael Hepburn, Dow Lohnes

Institutional Excellence Award 2012

From ACUTA Headquarters: Looking Back to the Future.......... Corinne Hoch, Executive Director

Board Report.......... Riny Ledgerwood, SDSU

lnfo Links .,......... .. Randy Hoyes, Univ. of Northern lowa

Committee Corner

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Documenting the Worth of an lT Degree

Member Benefit of the Month: ACUTA Community

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Predictive Mathematical Model For Polyhydroxybutyrate Synthesis In Escherichia Coli, Angela Dixon

Engineering Datasets

Polyhydroxybutyrate has been studied as a potential biodegradable replacement for petrochemical plastics. Polyhydroxybutyrate synthesis is not native to Escherichia coli, but the genes have successfully been inserted through plasmids. However, polyhydroxybutyrate production needs to be more cost-effective before it can be commercially produced. A mathematical model for polyhydroxybutyrate synthesis was developed to identify genes that could be altered to increase polyhydroxybutyrate production. The major metabolic pathways included in the model were glycolysis, acetyl coenzyme-A synthesis, tricarboxylic acid cycle, glyoxylate bypass, and polyhydroxybutyrate synthesis. Reactions were modeled using kinetic mechanisms identified for each enzyme. The transcriptional network was incorporated into the …

Selection Of Temperature Measuring Sensors Using The Analytic Hierarchy Process, Shadi Mohammad Al-B'Ool

Systems Science and Industrial Engineering Faculty Scholarship

This study presents an analytic hierarchy process (AHP) method to objectively select the best temperature sensor from among different alternative sensors in a certain industrial application. The underlying decision method based on AHP methodology, ranks temperature sensors with different features with a score resulting from the synthesis of relative preferences of each alternative with respect to the others at different levels considering independent evaluation criteria and sub-criteria. At each level, relative preferences of each candidate alternative with respect to the upper immediate level are calculated from pair-wise comparisons among the candidate alternative sensors with respect to a selected application. Pair-wise …

Towards Interval Techniques For Model Validation, Jaime Nava, Vladik Kreinovich

Departmental Technical Reports (CS)

Most physical models are approximate. It is therefore important to find out how accurate are the predictions of a given model. This can be done by validating the model, i.e., by comparing its predictions with the experimental data. In some practical situations, it is difficult to directly compare the predictions with the experimental data, since models usually contain (physically meaningful) parameters, and the exact values of these parameters are often not known. One way to overcome this difficulty is to get a statistical distribution of the corresponding parameters. Once we substitute these distributions into a model, we get statistical predictions …

Propagating Range (Uncertainty) And Continuity Information Through Computations: From Real-Valued Intervals To General Sets, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the main problems of interval computations is to find an enclosure Y that contains the range f(X₁, ..., X_n) of a given function f(x₁, ..., x_n) over given intervals X₁, ..., X_n. Most of the techniques for estimating this range are based on propagating the range through computations. Specifically, we follow the computations of f(x₁, ..., x_n) step-by-step: we start with ranges X₁, ..., X_n of the inputs, and then we sequentially compute the enclosures for the ranges of …

Longitudinal Evaluation Of A Gis Laboratory In A Transportation Engineering Course, Ghulam H. Bham, Dan Cernusca, Ronaldo Luna, Uday R.R. Manepalli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper focuses on the potential impact of student-centered feedback for enhancing the learning experience of civil engineering students that used a geographic information system (GIS) based tutorial in a transportation engineering course. the tutorial was implemented in a laboratory environment developed as a self-guided activity supported by a web-Based learning system. the formative research proposed in this study includes a series of four successive implementations of this laboratory. Students' performance, beliefs, and perceptions were monitored by using a mixed methods design approach and weaknesses identified from early implementations were addressed before the next implementation of the laboratory activity. the …

Introducing Porous Silicon As A Sacrificial Material To Obtain Cavities In Substrate Of Soi Wafers And A Getter Material For Mems Devices, Wajihuddin Mohammad

Doctoral Dissertations

Microelectromechanical system (MEMS) resonators have been a subject of research for more than four decades. The reason is the huge potential they possess for frequency applications. The use of a MEMS resonator as the timing element has an experimental history and huge progress has been made in this direction. Vacuum encapsulated MEMS resonators are required for high precision frequency control. Hence, a device with a high quality factor and durability is needed. In this effort, a new process for producing a cavity in the substrate of Silicon on insulator (SOI) MEMS devices and augmenting it with a getter using porous …

Selection Of Temperature Measuring Sensors Using The Analytic Hierarchy Process, Tarek Al-Hawari, Shadi Mohammad Al-B'Ool, Amer Momani

Systems Science and Industrial Engineering Student Scholarship

This study presents an analytic hierarchy process (AHP) method to objectively select the best temperature sensor from among different alternative sensors in a certain industrial application. The underlying decision method based on AHP methodology, ranks temperature sensors with different features with a score resulting from the synthesis of relative preferences of each alternative with respect to the others at different levels considering independent evaluation criteria and sub-criteria. At each level, relative preferences of each candidate alternative with respect to the upper immediate level are calculated from pairwise comparisons among the candidate alternative sensors with respect to a selected application. Pair-wise …

Considerations For Numerical Modeling Of Inverted Wings In Ground Effects, Graham Doig, Tracie J. Barber

Aerospace Engineering

No abstract provided.

Effect Of Gold Content On The Reliability Of Snagcu Solder Joints, Jianbiao Pan, J. Silk, M. Powers, P. Hyland

Industrial and Manufacturing Engineering

Electroplated Ni/Au over Cu is a popular metallization for printed circuit board finish as well as for component leads, especially wire-bondable high-frequency packages, where the gold thickness requirement for wire bonding is high. The general understanding is that less than 3 wt% of Au is acceptable in SnPb solder joints. However, little is known about the effect of Au content on the reliability of SnAgCu solder joints. The purpose of this paper is to determine the acceptable level of Au in SAC305 solder joints. Three different package platforms with different Au thicknesses were assembled on boards with two different Au …

Performance Of Elotex®Copra900 As A Corrosion Inhibitor, Niall Holmes

Other resources

Corrosion inhibitors as cement additions consist of powders or solutions that are added to concrete when mixed to prevent or delay corrosion. This paper presents an early-age evaluation of a new corrosion inhibitor, namely ELOTEX^®COPRA900 following a corrosion and durability study on concrete samples with different cementitious materials.

A comparison of the corrosion inhibition properties of ELOTEX^®COPRA900 against a well known and established corrosion inhibitor on the market, namely Calcium Nitrite and a control with no corrosion inhibitor product. Calcium Nitrite works by increasing the threshold of chlorides required for corrosion to begin. ELOTEX^®COPRA900 …

China Earthquake Reconnaissance Report: Performance Of Transportation Structures During The May 12, 2008, M7.9 Wenchuan Earthquake, Wen-Huei Phillip Yen, Genda Chen, Mark Yashinski, Youssef M.A. Hashash, Curtis J. Holub, Kehai Wang, Xiaodong Guo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This report documents the lessons learned from damage caused in the May 12, 2008, M7.9 earthquake in Wenchuan County, China. The damage to the 14 observed bridges reminded the researchers of damage suffered during the 1971 San Fernando Earthquake in California. The bridges had few seismic details such as long seats, large shear keys, or tightly spaced transverse reinforcement. Most arch and girder bridges collapsed due to surface rupturing of the seismic faults in the Longmen-Shan thrust zone. A significant portion of roadways and bridges were pushed away or buried by landslides in the steep slopes of mountainous terrain. Damage …

Performance Analysis Of A Variable Conductance Heat Pipe, Herron Arreola

Aerospace Engineering

This report examines the analysis of a donated Boeing variable conductance heat pipe with unknown performance characteristics. These characteristics were found through experimental means by utilizing 14 thermocouples attached to various locations on the heat pipe, the heaters and to the insulation. Although the maximum axial heat transport capability could not be determined due to the limited number of strip heaters available, the maximum radial heat flux capability of the heat pipe was found to be 2.46 W/in². The experiment also revealed that increasing the input power decreased the burn out inclination angle and that using a coolant …

Constrained Hermite Tls For Mesh-Free Derivative Estimation Near And On Boundaries, Robert A. Mcdonald, Alejandro Ramos

Aerospace Engineering

A Taylor series least-squares approach to estimating derivatives on scattered data is extended to include derivative observation or specification. This approach allows improved estimation of derivatives near boundaries as compared with the standard ghost node approach. It also enables a unique method of estimating derivatives in a surface using only surface data.

Integrating Science And Policy: A Case Study Of The Hubbard Brook Research Foundation Science Links Program, Charles T. Driscoll, Kathy Fallon Lambert, Kathleen C. Weathers

Civil and Environmental Engineering - All Scholarship

Scientists, related professionals, and the public have for decades called for greater interaction among scientists, policymakers, and the media to address contemporary environmental challenges. Practical examples of effective “real-world” programs designed to catalyze interactions and provide relevant science are few. Existing successful models can be used, however, to develop and expand the work of integrating, synthesizing, and communicating ecosystem science for environmental policy and natural-resource management. We provide an overview of the structure and strategies used in the Hubbard Brook Research Foundation Science Links program, now in its thirteenth year as a successful boundary-spanning organization. We detail project activities and …

Numerical Study Of An Ion-Exchanged Glass Waveguide Using Both Two-Dimensional And Three-Dimensional Models, Pengfei Wang, Yuliya Semenova, Jie Zheng, Qiang Wu, Agus Hatta, Gerald Farrell

Articles

A numerical study is carried out to compare the two-dimensional (2-D) case and three-dimensional (3-D) case for the modelling of an ion-exchanged glass waveguide. It is shown that different waveguide widths on the photomask correspond to different ion concentration distributions after an annealing process. A numerical example is presented of two waveguide sections with different widths indicates that due to the abrupt change of the waveguide width, a 3-D theoretical model is required for an accurate prediction of the parameters of ion-exchanged glass waveguides. The good agreement between the modelled and measured results proves that the developed 3-D numerical model …

Monitoring The Early-Age Hydration Of Self-Compacting Concrete Using Ultrasonic P-Wave Transmission And Isothermal Calorimetry, Bram Desmet, Kelly Chrysanthe Atitung, Miguel Angel Abril Sanchez, John Vantomme, Dimitri Feys, Nicolas Robeyst, Katrien Audenaert, Geert De Schutter, Veerle Boel, Gert Heirman, Özlem Cizer, Lucie Vandewalle, Dionys Van Gemert

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Early-Age Hydration (B48 H) of a Series of Self-Compacting Concretes and Corresponding Mortars and One Traditionally Vibrated Concrete and Mortar is Monitored in a Continuous Way using Ultrasonic Testing and Isothermal Calorimetry. the Mixtures Differ in Type of Mineral Addition, Superplasticizer, Cement, Cement-To-Powder Ratio and Water-To-Powder Ratio. the Influence of These Different Mixture Compositions on the Kinetics of the Hydration during the First Days of the Hydration is Characterized by the Heat Production Rate Q and the Evolution of the P-Wave Velocity, which is a Consequence of the Microstructural Changes. the Variations in the Acceleration Caused by Mineral Additions …

Computational Studies Of Ion Transport In Polymer Electrolytes, Hui Wu

Doctoral Dissertations

Improving ionic conductivity and lithium mobility in polymer electrolytes is important for their practical use for battery electrolytes. In this study, a combination of molecular dynamics and Monte Carlo simulations was used to bring insight into lithium ion transport in poly(ethylene oxide) (PEO) with plasticizers and also next to alumina solid surface doped with lithium salt. The simulations were performed using a moderately high molecular weight polymer (Mn = 10,000 g/mol) at an EO:Li ratio of 15. For the plasticized system, the PEO with LiN(CF3SO 2)2 (LiTFSI) was mixed with 10 wt% plasticizers that included either cyclic ethylene carbonate …

Bridge Damage Models For Seismic Risk Assessment Of Oregon Highway Network, Peter Dusicka, Jeffery Roberts

TREC Final Reports

The highway transportation network of the United States relies on the health and integrity of major infrastructure elements such as bridges. Frequently traveled parts of Oregon are within the seismically active Pacific Northwest and many of the bridges were designed and built to lateral demands that were assumed to be less than the current expectation, a deficiency caused by our growing awareness of seismic hazard and our enhanced understanding of the non-linear response of bridges. This vulnerability to damage from earthquakes can result in not only immediate damage, but also in potentially lingering economic impact caused by the disruption to …

Graphene Formation On Step-Free 4h-Sic(0001), M. L. Bolen, R. Colby, E A. Stach, Michael A. Capano

Birck and NCN Publications

Step-free SiC was thermally decomposed in vacuum to better understand graphene formation in the absence of step fronts. Atomic force microscopy revealed graphene nucleating at surface pits that preferentially form along SiC{1 $(1) over bar $ 00} planes. The density of these pits is 1 x 10(8)cm(-2), which is three orders of magnitude greater than the measured density of SiC threading dislocations. Additionally, Raman spectroscopy demonstrated that graphene on step-free regions have a redshifted 2D peak position and a smaller peak width than does graphene grown on stepped regions. This difference is attributed to film thickness, which is confirmed by …

The Significance Of In Situ Conditions In The Characterization Of Gasb Nanopatterned Surfaces Via Ion Beam Sputtering, Osman El-Atwani, Jean Paul, Alex Cimaroli, Anastassiya Suslova, Sami Ortoleva

Birck and NCN Publications

A systematic study is conducted in order to elucidate the underlying mechanism(s) for nanopatterning with low-energy irradiation of GaSb (100) under normal incidence. Ion energies between 50 and 1000 eV of Ar+ and ion fluences of up to 10(18) cm(-2) were employed. Characterization of the shallow (e.g., 1 to 6 nm) amorphous phase region induced by irradiation and the subsurface crystalline phase region is accomplished with low-energy ion scattering spectroscopy and x-ray photoelectron spectroscopy, respectively. In situ studies are conducted due to the strong chemical affinity for oxygen of GaSb. The studies conclude that at energies below 200 eV, the …

Laser Direct Write Of Silicon Nanowires, James Mitchell, Se Jun Park, C Adam Watson, Pornsak Srisungsitthisunti, Chookiat Tansarawiput, Minghao Qi, Eric Stach, Chen Yang, Xianfan Xu

Birck and NCN Publications

Using laser direct writing in combination with chemical vapor deposition to produce nanometer scale electronics holds several advantages over current large scale photolithography methods. These include single step electrical interconnect deposition, mask-less patterning, and parallel processing. When taken together they make quick production of individualized electronic circuits possible. This work demonstrates the ability of combining laser direct write and chemical vapor deposition to produce silicon wires a few hundred nanometers wide. Optimized parameters will be discussed, with a particular emphasis paid to the laser-material interactions. The feasibility for electronic applications will be shown by examining the deposition formation on a …

A Remote Interrogation System For Monitoring Concrete Performance Exposed To Environmental Action, Niall Holmes

Other resources

The performance of the surface zone of concrete is acknowledged as a major factor governing
the rate of deterioration of reinforced concrete structures as it provides the only barrier to the
ingress of water containing dissolved ionic species such as chlorides which, ultimately,
initiate corrosion of the reinforcement. In-situ monitoring of cover-zone concrete is critical in
attempting to make realistic predictions as to the in-service performance of the structure. To
this end, this paper presents developments in a remote interrogation system to allow
continuous, real-time monitoring of the cover-zone concrete from an office setting. Use is
made of a multi-electrode …

Nebraska Blueprint – Fall/Winter 2011

Nebraska Blueprint (Student Publication)

Table of Contents:

From the Editor

Engi-Briefs

Dean Tim Wei and the Future of Nebraska Engineering

Researching Safety on the Highway – "Cody S. Stolle, a graduate research assistant at UNL's Midwest Roadside Safety Facility, recently conducted research on cable median wires to reduce the number of deadly car highway accidents."

Husker Alum Returns – Dr. Kim Blair, Mechanical Engineering alumnus, spoke as part of the Pierson Lecture Series on innovation and technology development.

Engineering Off the Road – UNL's Baja SAE [Society of Automotive Engineers] team placed 3rd in suspension and traction, 7th in tractor pull, 11th in maneuverability, …