Engineering Commons^™

Investigation Of Surface Topology Effects On Metal Flow Of Aluminum And Steel During Hot Compression, Andrew Richard Matcha

Master's Theses (2009 -)

An investigation was conducted to study the effect of die surface roughness and lay on metal flow and the friction factor under lubricated hot compression. 6061-T6 aluminum and AISI 1018 steel rings and rectangular bar stock workpieces were compressed on H-13 tool steel platens of varying roughnesses ranging from Ra 0.25 – 6.1 µm (10 – 240 µin). Each platen was machined in such a way to ensure that the surface roughness would be unidirectional. Platen temperatures of 149 °C and 204 °C (300 °F and 400 °F) were used for all aluminum ring samples whereas platen temperatures ranging from …

Effect Of Low Reactivity Fuel On Reaction Wave Growth Of Dual-Fuel Stratified Mixtures In A Rapid Compression Machine, David J. Roulo

Master's Theses (2009 -)

For over 40 years, researchers have been studying homogenous charge compression ignition (HCCI) as a combustion strategy to improve the efficiency and emissions of the internal combustion strategy. Although early results were promising, it has been since discovered that HCCI engines only operate to their potential over a narrow load band. To remedy this, introducing inhomogeneities has been suggested as a method of controlling HCCI combustion in such a way to improve its usefulness. One such inhomogeneity is referred to as fuel octane number stratification and consists of port injecting a low reactivity fuel, allowing it to become well mixed, …

Optimal Conditions For Measuring Ignition Quality In Non-Engine Tests, Ashley Hatzenbihler

Master's Theses (2009 -)

Experiments and simulation work were conducted to explore the conditions that influence ignition events in a constant volume environment. Experiments were conducted in a Fuel Ignition Tester, produced by CFR Engines, Inc., and in a prototype combustion chamber to observe the combustion of diesel fuels and primary reference fuels. These experiments attempted to isolate experimental conditions that would provide repeatable pressure measurements. These experiments showed that the fuel spray properties and the environmental conditions, such as initial temperature and initial pressure, are significantly influential in these results. Simulation work was conducted in Converge 2.2.0 to explore these conditions further. The …

Effects Of Radiation And Egr On Pollutant Formation In High-Pressure Constant Volume Spray Combustion, Khaled Mosharraf Mosharraf Mukut

Master's Theses (2009 -)

Soot formation is a complex process and the actual soot formation methodology is still a mystery. Numerically modeling of soot requires successful coupling of turbulence, chemistry and radiation modeling. In the present study, a comprehensive sensitivity study is conducted to see the effect of radiation and exhaust gas recirculation (EGR) on soot and NOX formation in a high pressure spray combustion scenario. The spray-A case (n-dodecane as fuel) from Engine Combustion Network (ECN) is used as the target condition. Two different soot modeling approaches have been considered: a semi-empirical two-equation model and a method of moments with interpolative closure (MOMIC). …

Detecting Invasive Insects Using Unmanned Aerial Vehicles, Brian Stumph

Master's Theses (2009 -)

A key aspect to controlling and reducing the effects invasive insect species have on agriculture is to obtain knowledge about the migration patterns of these species. Current state-of-the-art methods of studying these migration patterns involve a mark-release-recapture technique, in which insects are released after being marked and researchers attempt to recapture them later. However, this approach involves a human researcher manually searching for these insects in large fields and results in very low recapture rates. This thesis proposes an automated system for detecting released insects using an unmanned aerial vehicle. Our system utilizes ultraviolet lighting technology, digital cameras, and lightweight …

Automated Shaped Charge Design: Applying Dakota Optimization To Cth Kinetic Energy Results, Sebastian Arcangelo Konewko

Master's Theses (2009 -)

Advances in computational power present an opportunity to further optimize the design of an engineered energetic system. This work presents the application of a proposed optimization scheme which combines the shock-physics hydrocode CTH with the DAKOTA optimization package to automate shaped-charge jet design. The formation of an explosively driven hypervelocity jet is highly dependent on the original shaped charge liner geometry. By parameterizing this geometry, and by developing a characteristic objective function from CTH simulations, a process can be established where the Dakota code iteratively builds an optimal shaped charge. This work attempts to use this methodology to reproduce a …

Design And Evaluation Of A Novel Ankle Joint For An Ankle Foot Orthosis For Individuals With Drop-Foot, Eileen Maya Baker

Master's Theses (2009 -)

Individuals who have had a stroke often ambulate with an ankle foot orthosis (AFO) to treat drop-foot, a common impairment preventing active ankle dorsiflexion. AFOs limit ankle plantarflexion or drop-foot, but also restrict ankle motion that introduces additional gait pathologies during ambulation. The goal of this study was to design a mechanical ankle joint for an articulated thermoplastic AFO to permit enhanced motion during stance. This novel ankle joint operated in two stages: 1) locked during swing to prevent drop-foot and 2) unlocked during stance to allow motion. This novel ankle joint was first tested with able-bodied subjects to ensure …

Evaluating Variability Of Urban Land Surface Temperatures Using Drone Observations, Joseph Naughton

Master's Theses (2009 -)

Temperature represents one of the largest impairments for rivers and streams across the United States. In Wisconsin alone, over 17 miles of streams are impaired for temperature. This situation is projected to get worse as urban development and climate change accelerate thermal stress on aquatic environments. Management solutions require accurate and reliable models that represent rainfall-runoff temperature dynamics – particularly the characterization of land surface temperatures and how this translates to urban runoff. However, current models may not reflect the thermal profiles of real-world systems because they rely on in-situ equipment limited to point measurements. Limited studies have considered the …

A Continuous And Static Water Contaminant Detection System Using Rf Microwave Principles, Rafee Mahbub

Master's Theses (2009 -)

A continuous, static, and non-interfering water contaminant detection method is presented to measure specific water contaminants (NaCl, MgCl2, and mixture of NaCl and MgCl2) using RF microwave principles. A coil is mounted on the surface of a glass tube and the liquid sample is placed inside of the tube. An external magnetic field generated by the coil continuously measures changes in radio frequency energy. The non-contact feature of the device allows a long sensor lifetime with high sensitivity for real-time measurements. The measurement parameter is reflection coefficient (S11) and the operating frequency is 10 MHz – 5 GHz. For NaCl …

Pedaling Asymmetry During Lower Limb Pedaling After Stroke, Benjamin Rappaport

Master's Theses (2009 -)

People with stroke pedal asymmetrically. There may be differences in their pedaling kinetics between their non-paretic and paretic lower limbs and compared to healthy age matched controls. Previous studies have measured pedaling related impairments and impairments with interlimb coordination using electromyography (EMG). These studies did not use torque as a measurement for pedaling related impairments and interlimb coordination impairments. Pedaling symmetry in the laboratory measuring the torque and work production will fill the gaps of the knowledge about motor compensation during lower limb pedaling. As well, pedaling symmetry has not been measured during fMRI because of the inability to measure …

Analysis Of Bjt Colpitts Oscillators - Empirical And Mathematical Methods For Predicting Behavior, Nicholas Jon Stave

Master's Theses (2009 -)

Oscillator circuits perform two fundamental roles in wireless communication –the local oscillator for frequency shifting and the voltage-controlled oscillator formodulation and detection. The Colpitts oscillator is a common topology used for theseapplications. Because the oscillator must function as a component of a larger system, theability to predict and control its output characteristics is necessary. Textbooks treating thecircuit often omit analysis of output voltage amplitude and output resistance and theliterature on the topic often focuses on gigahertz-frequency chip-based applications.Without extensive component and parasitics information, it is often difficult to makesimulation software predictions agree …

Low-Cost, Water Pressure Sensing And Leakage Detection Using Micromachined Membranes, Farhana Anwar

Master's Theses (2009 -)

This work presents the only known SOI membrane approach, using Microelectromechanical systems (MEMS) fabrication techniques, to address viable water leakage sensing requirements at low cost. In this research, membrane thickness and diameter are used in concert to target specific stiffness values that will result in targeted operational pressure ranges of approximately 0-120 psi. A MEMS membrane device constructed using silicon-on-insulator (SOI) wafers, has been tested and packaged for the water environment. MEMS membrane arrays will be used to determine operational pressure range by bursting.Two applications of these SOI membranes in aqueous environment are investigated in this research. The first …

Local Density Parameters With Respect To Powder Metal Sintering Process, Jungu Kang

Master's Theses (2009 -)

Mapping of local density fractions and a mathematically approximated density fraction model of sintered powder metal were studied in this research. Specimens were studied utilizing an image analysis software, HCImage, and local density fraction maps were acquired for each sintering condition. A regression function of sintering temperature, sintering time, radius and depth was then derived from the local density fractions. The experimental procedures including specimen preparation, image analysis, and data analysis are demonstrated in detail within this research. Through the local density maps and the regression function, two objectives were sought as follow:1. Determination of the density fraction gradient …

Correlating Pressure, Fluidization Gas Velocities, Andsolids Mass Flowrates In A High-Pressurefluidized Bed Coal Feed System, Jacob Talailetalalelei Tuia

Theses and Dissertations

The goal of this thesis was to understand what parameters would be most impactful when delivering dry, pulverized coal in a dilute-phase, with a high-pressure feed-system to a pressurized oxy-combustion (POC) reactor. Many studies have conveyed materials in dense-phase plugs at high-pressure or in dilute-phase flows at atmospheric pressure. Very few studies have fluidized and conveyed materials in dilute-phase flows at high pressure, as we needed to. Additionally, studies which might have been applicable based upon system -pressure and -phase delivered findings that were empirically based and therefore not specifically applicable to non-similar systems. 220 different tests were ran using …

Joint Analysis Of And Applications For Devices With Expanding Motions, Kendall Hal Seymour

Theses and Dissertations

Origami has been extensively studied by engineers for its unique motions and ability to collapse to small volumes. Techniques have been studied for replicating origami-like folding motion in thick materials, but limited practical applications of these techniques have been demonstrated. Developable mechanisms are a new mechanism type that has a similar ability to collapse to a low profile. The cylindrical developable mechanism has the ability to emerge from and conform to a cylindrical surface. In this work, a few practical applications of devices with novel expanding motions are presented. The design and testing of an origami-inspired deployable ballistic barrier, which …

Advanced Measurement Techniques For Enabling Multiphase Reactors And Flow Systems For Sustainable And Cleaner Processes, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

Local Receptive Fields Based Extreme Learning Machine With Hybrid Filter Kernels For Image Classification, Bo He, Yan Song, Yuemei Zhu, Qixin Sha, Yue Shen, Tianhong Yan, Rui Nian, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, an Innovative Method Called Extreme Learning Machine with Hybrid Local Receptive Fields (Elm-Hlrf) is Presented for Image Classification. in This Method, Filters Generated by Gabor Functions and the Randomly Generated Convolution Filters Are Incorporated into the Convolution Filter Kernels of Local Receptive Fields based Extreme Learning Machine (Elm-Lrf). Extreme Learning Machine (Elm) is Derived from Single Hidden Layer Feed-Forward Neural Networks, and the Parameters of its Hidden Layer Can Be Generated Randomly. as Locally Connected Elm, Elm-Lrf Directly Processes Information with Strong Correlations Such as Images and Speech. in This Paper, Two Main Contributions Are Proposed to …

A Set-Theoretic Model Reference Adaptive Control Architecture With Dead-Zone Effect, Ehsan Arabi, Tansel Yucelen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

By introducing a system error dependent learning rate, the recently proposed set-theoretic model reference adaptive control architecture provides user-defined worst-case performance guarantees on the system error between an uncertain dynamical system of interest and a given reference model. In this architecture, the adaptation process is always active. However, it is of practical interest to stop the adaptation process when it is not needed (i.e., in the presence of small system errors). Motivated from this standpoint, we present a new set-theoretic model reference adaptive control architecture with dead-zone effect. The key feature of our framework utilizes a modified and continuous generalized …

Multi-Objective Optimization Approach To Find Biclusters In Gene Expression Data, Jeffrey Dale, Junya Zhao, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

Gene expression levels of organisms are measured by DNA microarrays. Finding biclusters in gene expression matrices provides invaluable information about effects of disease at the genetic level. These biclusters could identify which genes are up-regulated/down-regulated under certain conditions. This paper investigates a methodology for evolutionary-based biclustering using the NSGA-II algorithm. It also presents an improvement to the recovery and relevance external validation metrics as well as a new method for synthetic data generation for biclustering. Results obtained demonstrate its effectiveness in discovering useful biclusters on varied synthetic data when applied with the average Spearman's rho measure as the fitness function.

Event-Triggered Adaptive Distributed State Estimation By Using Active-Passive Sensor Networks, Akhilesh Raj, S. Jagannathan, Tansel Yucelen

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a novel event-triggered adaptive observer for each node in the heterogeneous sensor networks (HSNs) in order to estimate state vector of an unknown target or process by using the sensed output when the input to the target/ process is unknown. A subset of nodes in the HSN referred to as active nodes, can sense the target periodically, estimate the target state vector by using their adaptive observer and can communicate the estimated state vector of the target with the neighboring nodes including passive nodes only at event triggered instants. The adaptive observer parameters of active nodes are …

Fully Adaptive Cloud Profiling Radar Simulation, J. Delong, M. A. Shattal, A. O'Brien, C. D. Ball, J. T. Johnson, G. E. Smith

Electrical and Computer Engineering Faculty Research & Creative Works

This paper demonstrates how the fully adaptive radar framework can be applied to cloud profiling radars. A simulation based on the GEOS5 nature run dataset is introduced in which the cloud profiling radar continuously adapts its pulse repetition frequency (PRF) such that the unambiguous range is 1.2 times the cloud column height. This process maximizes the (PRF) which would in turn maximize the unambiguous velocity estimate.

Feasibility Study Of Intelligent Lvad Control For Optimal Heart Failure Therapy., John A. Karlen Iii

Electronic Theses and Dissertations

Background: Left ventricular assist devices (LVAD) are operated at constant speeds (rpm), consequently, pump flow is passively determined by the pressure difference between the LV and aorta. Since the diastolic pressure gradient (~70 mmHg) is much larger than the systolic gradient (~10 mmHg), the majority of pump flow occurs during systole. This limitation results in sub-optimal LV volume unloading, LV washing, and diminished vascular pulsatility that may be associated with increased risk for clinically-significant adverse events, including stroke, bleeding, arteriovenous malformations, and aortic insufficiency. To address these clinical adverse events, an intelligent control strategy using pump speed modulation was developed …

Simulation Of A Continuum Tumor Model Using Distributed Computing., Dylan A Goodin

Electronic Theses and Dissertations

Mathematical modeling aims to provide a theoretical framework for understanding tissue dynamics and for establishing treatment response for diseased tissues, such as tumors. Previously published continuum models have successfully represented idealized two-dimensional and three-dimensional tissue for short periods of time. A recently published continuum model of cancer increases model complexity and describes three-dimensional tissue that, due to the required complexity of the geometric multigrid solver, can only be feasibly applied to millimeter-scale simulations. Furthermore, the computational cost for such models has hindered their application in the laboratory and in the clinic. With computational demands greatly outpacing current openMP-based approaches on …

High Dimensional Data Clustering Using Self-Organized Map, Ruth Ema Febrita, Wayan Firdaus Mahmudy, Aji Prasetya Wibawa

Knowledge Engineering and Data Science

As the population grows and e economic development, houses could be one of basic needs of every family. Therefore, housing investment has promising value in the future. This research implements the Self-Organized Map (SOM) algorithm to cluster house data for providing several house groups based on the various features. K-means is used as the baseline of the proposed approach. SOM has higher silhouette coefficient (0.4367) compared to its comparison (0.236). Thus, this method outperforms k-means in terms of visualizing high-dimensional data cluster. It is also better in the cluster formation and regulating the data distribution.

Implementation Of View Factor Model And Radiative Heat Transfer Model In Moose, Abdurrahman Ozturk

Theses and Dissertations

View factors are functions that represent the geometric relationship between surfaces. They are important parameters for radiative heat transfer calculations. View factor catalogues are available for simple geometries in the current literature. However, in the case of complicated geometry, analytical or numerical methods are needed to evaluate view factors. The Monte Carlo (MC) method is the most flexible one among numerical methods, which are used to calculate view factors, since it can be applied to any geometry.

When experimental studies are not affordable to conduct, modeling of engineering problems gains more importance. Idaho National Laboratory (INL)’s finite element framework Multiphysics …

Fractional Order And Virtual Variable Sampling Design Of Repetitive Control For Power Converters, Zhichao Liu

Theses and Dissertations

With the growth of electricity demand and renewable energy power source, power converter becomes a more and more significant component in electrical power systems. The requirement of the power converter controller is to produce an accurate and low-distorted voltage or current under different load conditions. Although the conventional controller can meet the requirement of some applications, it requires accurate knowledge of the system model and cannot provide a satisfactory result especially under nonlinear loads or sudden load change. Repetitive control (RC) presents an attractive solution to achieve excellent steady-state tracking error and low total harmonic distortion for periodic signals, and …

Dc Bus Stabilization And Dynamic Performance Improvement Of A Multi-Converter System, Silvia Arrua

Theses and Dissertations

Evolution of semiconductor devices is allowing to implement power electronics technology in a variety of applications, moving traditional AC systems to more efficient and reliable DC systems. Some examples are shipboard power distribution systems, DC microgrids, electric vehicles and more electric aircrafts. Even though these types of systems offer significant advantages that make them attractive in different areas, the interconnection of feedback-controlled power converters leads to emergent dynamic behavior that a system designer must take into account to ensure proper operation of the system. Additionally, system reconfiguration is very likely to happen in applications such as a shipboard power distribution, …

The Contribution Of Adipose Tissue From Ovariectomized Mice To Colon Cancer, Meredith Smith Carson

Theses and Dissertations

Obesity is considered a major public health concern worldwide due to the increased incidences of metabolic dysfunction and cancer risk. The obese state is, in part, attributable to the overconsumption of calorie-dense foods commonly seen in a standard Western diet, which aids in the progression of chronic, lowgrade inflammation. The role of estrogen varies depending on menopausal status, where estrogen deficiency coupled with increased visceral fat associated with post-menopause leads to increased secretions of pro-inflammatory adipokines and cytokines. However, the presence of estrogen in a premenopausal state has been shown to attenuate the pro-inflammatory response, which has been demonstrated when …

Carbon Nanotube And Cellulose Nanocrystal Hybrid Films, Mingzhe Jiang, Robert Seney, Paul Charles Bayliss, Christopher L. Kitchens

Publications

The use of cellulose nanocrystals (CNC) in high performance coatings is attractive for micro-scale structures or device fabrication due to the anisotropic geometry, however CNC are insulating materials. Carbon nanotubes (CNT) are also rod-shaped nanomaterials that display high mechanical strength and electrical conductivity. The hydrophobic regions of surface-modified CNC can interact with hydrophobic CNT and aid in association between the two anisotropic nanomaterials. The long-range electrostatic repulsion of CNC plays a role in forming a stable CNT and CNC mixture dispersion in water, which is integral to forming a uniform hybrid film. At concentrations favorable for film formation, the multiwalled …

Bs News July/August

Building Services Engineering

No abstract provided.