Engineering Commons^™

Magnetic Ordering In The Rare Earth Intermetallic Compound Tb₂Ti₃Ge₄: Magnetization And Neutron Diffraction Studies, Satish K. Malik, Jagat Lamsal, R. L. De Almeida, S. Quezado, William B. Yelon, V. O. Garlea, A. V. Morozkin, R. Nirmala

Physics Faculty Research & Creative Works

Magnetization and neutron diffraction studies on a polycrystalline Tb2Ti3Ge4 sample (orthorhombic Sm5Ge4-type structure, space group Pnma, No. 62) have been carried out. This compound is found to order antiferromagnetically at ~18 K (TN). The magnetization (M) versus field (H) isotherms obtained at 2, 3, 5, and 10 K indicate a field-induced antiferromagnetic to ferromagnetic transition in fields of the order of 0.5 T. The saturation magnetization value at 2.5 K (M extrapolated to 1/H-->0) is only ~5.6µB/Tb3+, suggesting the possible presence of crystal field effects with or without a persisting antiferromagnetic component. Neutron powder diffraction data at 10 K …

Experimental Painting Of The I-64 Riverside Parkway In Louisville, Ky, Rick Younce, Theodore Hopwood Ii, Sudhir Palle

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet conducted a large-scale zone maintenance painting operation on 13 elevated steel bridges along the I-64 Riverside Parkway in Louisville, KY in 2007. That work included abrasive blast-cleaning and painting of steel underlying open deck joints on 3.2 miles of steel structures. The painting was performed by spray application of one coat of a calcium sulfonate alkyd coating. The painting covered an area of 237,060 ft2 of steel cleaned and painted at a unit cost of $15.82/ft2.

The project incorporated a high level of containment as the existing coating possessed lead-based paints and the project was located …

Shear Banding Or Not In Entangled Dna Solutions Depending On The Level Of Entanglement, Pouyan E. Boukany, Shi-Qing Wang

College of Polymer Science and Polymer Engineering

Entangled DNA solutions are ideal as a model system to examine nonlinear shear flow behavior. Even when the number of entanglements per chain, Z, is higher than 100, the solution is still soft enough with an elastic plateau modulus under 100 Pa and is thus amenable to experimental study by commercial rotational rheometry without ambiguity and uncertainty. We have investigated nonlinear flow behavior of three entangled DNA solutions with Z=24, 60, and 156, respectively, using a combination of particle-tracking velocimetric (PTV) and conventional rheometric measurements. We explore questions such as (a) whether shear banding also occurs in moderately entangled solutions, …

A Successful Interdisciplinary Course On Computational Intelligence, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents experiences from the introduction of a new three hour interdisciplinary course on computational intelligence (CI) taught at the Missouri University of Science and Technology, USA at the undergraduate and graduate levels. This course is unique in the sense that it covers five main paradigms of CI and their integration to develop hybrid intelligent systems. The paradigms covered are artificial immune systems (AISs), evolutionary computing (EC), fuzzy systems (FSs), neural networks (NNs) and swarm intelligence (SI). While individual CI paradigms have been applied successfully to solve real-world problems, the current trend is to develop hybrids of these paradigms …

Online Optimal Neuro-Fuzzy Flux Controller For Dtc Based Induction Motor Drives, N. Sadati, S. Kaboli, H. Adeli, E. Hajipour, Mehdi Ferdowsi

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper a fast flux search controller based on the Neuro-fuzzy systems is proposed to achieve the best efficiency of a direct torque controlled induction motor at light load. In this method the reference flux value is determined through a minimization algorithm with stator current as objective function. This paper discusses and demonstrates the application of Neurofuzzy filtering to stator current estimation. Simulation and experimental results are presented to show the fast response of proposed controller.

Power Sharing In A Double-Input Buckboost Converter Using Offset Time Control, Deepak Somayajula, Mehdi Ferdowsi

Electrical and Computer Engineering Faculty Research & Creative Works

Multi-input power electronic converters have been gaining popularity in applications such as renewable energy sources and hybrid electric vehicles due to their reduced component count. In this paper, a new control method is introduced and successfully applied to a double-input buckboost converter to adjust the power supplied by each one of the sources. The control scheme is based on controlling the offset time between the switching commands while switching frequency is kept constant. Theoretically, it is proved that the offset time between the switch commands has a direct impact on the amount of current drawn from each source. The proposed …

Stress-Strain Behavior Of Perfluorosulfonic Acid Membranes At Various Temperatures And Humidities: Experiments And Phenomenological Modeling, Ahmet Kusoglu, Yaliang Tang, Michael Santare, Anette M. Karlsson, Simon Cleghorn, William B. Johnson

Mechanical Engineering Faculty Publications

The constitutive response of perfluorinated sulfonic acid (PFSA) membranes based on tensile testing is investigated, and a phenomenological constitutive model for the elastoplastic flow behavior as a function of temperature and humidity is proposed. To this end, the G'Sell–Jonas (1979, “Determination of the Plastic Behavior of Solid Polymers at Constant True Strain Rate,” J. Mater. Sci., 14, pp. 583–591) constitutive model for semicrystalline polymers is extended by incorporating, in addition to temperature, relationships between the material constants of this model and the measured relative humidity. By matching the proposed constitutive model to the experimental stress-strain data, useful material constants …

Undergraduate Engineers Develop Hydraulic Servo Control Systems Using Model-Based Design With Simulink, Charles Birdsong

Mechanical Engineering

In the past, control engineering was the exclusive province of computer and electrical engineers with advanced degrees and years of experience in low-level programming languages. Today, engineers and students alike can use Model-Based Design to rapidly design and implement real-time control systems without having to learn low-level programming. Used throughout the automotive and aerospace industries, Model-Based Design places a high-level system model at the center of development. This approach helps engineering students understand not only the basic physics of system components, but also the interaction between components and the behavior of the overall system.

Photopatternable Polymeric Membranes For Optical Oxygen Sensors, Raghu Ambekar, Jongwon Park, David Henthorn, Chang-Soo Kim

Chemical and Biochemical Engineering Faculty Research & Creative Works

A new class of optical oxygen sensor that can be photopatternable by traditional UV lithography is presented. They are fabricated using photopatternable spin-on silicone (polydimethylsiloxane, PDMS) with oxygen sensitive luminescent dyes. It has a good adhesion property and can be applied on glass or on photopolymer (SU-8) without any additional surface treatments. The optimum mixture composition for patternable oxygen sensitive membranes is investigated and its optical properties are characterized. Proof-of-concepts for two applications, intensity-based oxygen sensing with SU-8 based structure and self-calibration fluidic oxygen sensor, are described. These photopatternable optical membranes will find many applications wherever small patterns of oxygen …

Small-Signal Impedance Measurement Of Power-Electronics-Based Ac Power Systems Using Line-To-Line Current Injection, Jing Huang, Keith Corzine, M. Belkhayat

Electrical and Computer Engineering Faculty Research & Creative Works

Naval ships as well as aerospace power systems are incorporating a greater degree of power electronic switching sources and loads. Although these components provide exceptional performance, they are prone to instability due to their high efficiency and constant power characteristics that can exhibit negative impedance nature at certain frequencies. When designing these systems, integrators must consider the impedance versus frequency at an interface (which designates source and load). Stability criteria have been developed in terms of source and load impedances for both dc and ac systems, and it is often helpful to have techniques for impedance measurement. For dc systems, …

Wavelet Based Adaptive Rbf Method For Nearly Singular Poisson-Type Problems On Irregular Domains, Nicolas Ali Libre, Arezoo Emdadi, Edward J. Kansa, Mohammad Shekarchi, Mohammad Rahimian

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

We present a wavelet based adaptive scheme and investigate the efficiency of this scheme for solving nearly singular potential PDEs over irregularly shaped domains. For a problem defined over Ω ∈ ℜ^d, the boundary of an irregularly shaped domain, Γ, is defined as a boundary curve that is a product of a Heaviside function along the normal direction and a piecewise continuous tangential curve. The link between the original wavelet based adaptive method presented in Libre, Emdadi, Kansa, Shekarchi, and Rahimian (2008, 2009) or LEKSR method and the generalized one is given through the use of simple Heaviside …

Support Vector Selection And Adaptation For Classification Of Remote Sensing Images, Gulsen Taskin Kaya, Okan Ersoy

Department of Electrical and Computer Engineering Technical Reports

Classification of nonlinearly separable data by nonlinear support vector machines is often a difficult task especially due to the necessity of a choosing a convenient kernel type. In this study, we propose a new classification method called support vector selection and adaptation (SVSA) that is applicable to both linearly and nonlinearly separable data in terms of some reference vectors generated by processing of support vectors obtained from the linear SVM. The method consists of two steps called selection and adaptation. In these two steps, once the support vectors are obtained by a linear SVM, some of them are rejected and …

Analysis Of Folded Core Sandwich Structures, Waleed Ahmed Ibrahim Mahmoud

Archived Theses and Dissertations

No abstract provided.

Removal Of Thm Precursor By Enhanced Coagulation, Yasmine Kamal Abdel-Maksoud

Archived Theses and Dissertations

No abstract provided.

Label Oriented Clustering For Social Network Groups, Ahmed El Kholy

Archived Theses and Dissertations

No abstract provided.

Collaborative Filtering For Domain Independent Recommendation, Rami El-Gawly

Archived Theses and Dissertations

No abstract provided.

A Condition Assessment Approach For Buildings, Sally Maher Naguib El-Gizawy

Archived Theses and Dissertations

No abstract provided.

Finite Element Model Updating Approach To Damage Identification In Beams, Mohamed Medhat Saada

Archived Theses and Dissertations

No abstract provided.

Correlating Threshold Power With Free-Space Bandwidth For Low-Directivity Antennas, Abu T.M. Sayem, Mark G. Douglas, Gernot Schmidt, Ben Petric, Mohammod Ali

Faculty Publications

This paper develops a threshold power rationale that can be used to demonstrate inherent compliance for portable wireless devices with specific absorption rate (SAR) limits over the 300-6000-MHz frequency range. This is achieved first by understanding the relationship between basic antenna parameters (bandwidth, operating frequency, and distance to the body) and SAR. From this, an upper limit is determined for the power transmitted by a portable wireless device such that the SAR will not exceed the compliance limit. Based on the presented computational and measured data, an empirical formula is developed for the threshold power as a function of the …

Evolution Of Tidal Amplitudes In The Eastern Pacific Ocean, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Global sea level (GSL) rise is well documented. However, changes in high waters, including the tidal contribution, are sometimes more relevant than GSL rise. Analysis of 34 long tidal records from the Eastern Pacific Ocean shows that K1 and M2 amplitudes (∣K₁∣ and ∣M₂∣) are increasing, except for ∣M2∣ in the Gulf of Panama. North of 18°N, ∣K1∣ and ∣M2∣ are both growing at 2.2% century⁻¹. The mean increase in total tidal amplitude (0.59 mmyr⁻¹) is less than the present GSL rise (1.7 mmyr⁻¹). However, mean sea level is nearly constant in the NE Pacific, so tidal evolution plays a …

A System For Measuring The Lift And Drag Forces Of A Spinning Golf Ball Held Fixed Within A Wind Tunnel, Ryan R. Miller

Master's Theses

A system was designed, built and tested in order to test the aerodynamic properties of a standard golf ball in a wind tunnel manufactured by ELD, Inc. model 406(B). The system consists of a rotating shaft, on which the golf ball is attached, connected to a two-axis force transducer. Additionally, an automated data acquisition system was built for enhanced precision of measurements. Data for wind speeds up to 160 ft/s and rotational speeds up to 8,600 rpm were obtained and analyzed. The purpose of the designed apparatus was to allow for studies to better understand the lift and drag coefficients …

Evaluation Of The Effects Of Powder Coating Cure Temperatures On The Mechanical Properties Of Aluminum Alloy Substrates, C. Maldonado, D. Diaz, J. Ranallo, R. Painter, W. Dahir, D. Hassouna, B. Gayer, E. Toss, I. Martinez, P. Stoyanov, J. Ogren, E. W. Lee, D. Piatkowski, Omar S. Es-Said

Mechanical Engineering Faculty Works

The effects of curing temperature, based on new, low-temperature powder coating methods and traditional high-temperature powder coating methods, were studied. Heat-sensitive aluminum alloys (2024-T3, 6061-T6, and 7075-T6) were subjected to two different heat-treatment cycles, which were based on temperatures of 121 and 204 degrees C. Findings indicate that although both cure temperatures achieved powder coatings adhesion and thickness appropriate for industrial uses, the high-temperature cure treatment negatively affected the mechanical properties.

Learning Image‐Text Associations, Tao Jiang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Web information fusion can be defined as the problem of collating and tracking information related to specific topics on the World Wide Web. Whereas most existing work on Web information fusion has focused on text-based multidocument summarization, this paper concerns the topic of image and text association, a cornerstone of cross-media Web information fusion. Specifically, we present two learning methods for discovering the underlying associations between images and texts based on small training data sets. The first method based on vague transformation measures the information similarity between the visual features and the textual features through a set of predefined domain-specific …

Temperature Influence And Heat Management Requirements Of Microalgae Cultivation In Photobioreactors, Thomas Hagen Mehlitz

Master's Theses

Microalgae are considered one of the most promising feedstocks for biofuel production for the future. The most efficient way to produce vast amounts of algal biomass is the use of closed tubular photobioreactors (PBR). The heat requirement for a given system is a major concern since the best algae growth rates are obtained between 25-30 °C, depending on the specific strain. A procedure to determine temperature influence on algal growth rates was developed for a lab-scale PBR system using the species Chlorella. A maximum growth rate of 1.44 doublings per day at 29 °C (optimal temperature) was determined. In addition, …

Programmer Friendly Refactoring Tools, Emerson Murphy-Hill

Dissertations and Theses

Tools that perform semi-automated refactoring are currently under-utilized by programmers. If more programmers adopted refactoring tools, software projects could make enormous productivity gains. However, as more advanced refactoring tools are designed, a great chasm widens between how the tools must be used and how programmers want to use them. This dissertation begins to bridge this chasm by exposing usability guidelines to direct the design of the next generation of programmer-friendly refactoring tools, so that refactoring tools fit the way programmers behave, not vice-versa.

Electro Hydrodynamic Manipulation Of The Process Of Self-Assembly Of Particles At Fluid-Fluid Interfaces, Muhammad Mansoor Janjua

Dissertations

This dissertation is divided into two parts, first deals with the numerical study of motion of dielectric particles subjected to nonuniform electric fields and second deals with the process of self-assembly of particles at fluid-fluid interfaces and subjected to uniform electric field normal to the interface. In the numerical study, the particles are moved using a direct simulation scheme (DNS) in which the fundamental equations of motion of fluid and solid particles are solved without the use of models. The motion of particles is tracked using a distributed Lagrange multiplier method (DLM) and the electric force acting on the particles …

Optimizing Container Retrieval Operation At A Port Container Terminal, Dejan Besenski

Dissertations

In the presence of major challenges, where ports are striving to improve their operation and stay competitive in the global market, the issue of port efficiency, particularly the intelligent management of straddle carriers is investigated in this study. A new approach is presented that optimizes container handling equipment operation and is beneficial for the terminal operator in terms of improving productivity, providing faster service and reducing operating cost, Also, the solution provides acceptable service for truckers, The operational strategies presented are able to assess the operation from the truckers' and terminal operators' perspective.

The research is structured into four different …

Surface And Bulk Passivation Of Multicrystalline Silicon Solar Cells By Silicon Nitride (H) Layer : Modeling And Experiments, Chuan Li

Dissertations

The objective of this dissertation is to study passivation effects and mechanisms in Si solar cells, specifically, the surface and bulk passivation by hydrogen-rich PECVD silicon nitride (SiN :H) antireflection layer on multicrystalline silicon (me-Si) solar cells.

The passivation of silicon surface can be achieved in two ways: by field-effect passivation and/or by neutralization of interface states. In other words, the deposition should result in a high value of fixed charge, Qf and /or a low value of interface state density, D1. The surface recombination velocity can be described by Shockley-Read-Hall (SRH) statistics.

Current SRH formalisms have failed to explain …

Precipitation Of Micro/Nanoparticles In Enhanced High Energy Dissipation Mixing Systems, Giuseppe Di Benedetto

Dissertations

Crystallization is the most common unit operation used in the pharmaceutical industry to synthesize active ingredients. Rapid development of a drug candidate is dependent on the ability to produce a desired drug substance with consistent properties, These properties include stability and purity, which are directly affected by the crystallization process and which affect, in turn, bioavailability, drug dissolution rate, drug stability, and shelf life.

The objective of this work is to produce micro/nanoparticle crystals within existent glass-lined pharmaceutical stirred-tank reactors by modifying the current reactor configuration to include features that can increase the local rate of energy dissipation in the …

Experiment And Modeling : Ignition Of Aluminum Particles With A Co2 Laser, Salil Mohan

Dissertations

Aluminum is a promising ingredient for high energy density compositions used in propulsion systems, explosives, and pyrotechnics. Aluminum powder fuel additives enable one to achieve higher combustion enthalpies and reaction temperatures. Therefore, to develop aluminum based novel and customized high density energetic materials, understanding of ignition and combustion kinetics of aluminum powders is required. In most practical systems, metal ignition and combustion occur in environments with rapidly changing temperatures and gas compositions. The kinetics of exothermic reactions in related energetic materials is commonly characterized by thermal analysis, where the heating rates are very low, on the order of 1 -50 …