Engineering Commons^™

Thermal Characterization Of Liquid Samples With Three-Dimensional On-Chip Micro Calorimeter, Hye Jeong Bak

Master's Theses (2009 -)

This thesis presents a three dimensional on-chip microfabricated calorimeter (μ-calorimeter) to extract thermal diffusivity and specific heat capacity of liquid samples. These thermal properties are used to understand thermal reaction behavior, obtain information of stability for reactant molecules, and characterize a material. Thermally characterized solvents can be utilized to investigate a solute. The μ-calorimeter introduced in this work has 3D wafer-scale structure. The μ-calorimeter consists of a reaction chamber, a nickel heater, and a resistance temperature detector (RTD) sensor. The reaction chamber enables analysis of 200 nl liquid samples. Also, its enclosed structure prevents liquid sample evaporation during an experiment. …

Fate Of Micropollutants During Pyrolysis Of Biosolids, John Ross

Master's Theses (2009 -)

Approximately 250 tons of organic micropollutants, including pharmaceuticals, antimicrobials, and hormones, are discharged to the environment during land application of wastewater biosolids annually. Reusing wastewater biosolids is vital to the sustainability of wastewater treatment, but current treatment processes do not remove micropollutants from biosolids in an efficient manner. Pyrolysis―the heating of biomass to temperatures between 400 and 800 °C under oxygen-free conditions―was proposed as a biosolids treatment process that could produce a beneficial soil amendment product, biochar, and remove micropollutants. The objective of this research was to determine the effect of pyrolysis temperature and residence time on the removal of …

Evaluation Of Heat Recovery Options For Improved Energy Efficiency Of A Manufacturing Facility, Allison Chouinard

Master's Theses (2009 -)

Nationwide process heating in the manufacturing sector accounts for 7,815 trillion BTU of energy use annually; this is roughly one-third of the sector's total energy consumption [Energetics Incorporated, 2014]. The U.S. Department of Energy estimates that seventy percent of process heating is fueled by the onsite burning of fossil fuels [Energetics Incorporated, 2014]. These fuel-fired process heating applications are prime opportunities for heat recovery projects capable of saving energy and, consequently, reducing operating costs. This thesis evaluates different methods for heat recovery in the Milwaukee manufacturing facility of STRATTEC Security Corporation. As a basis for this work, the overall energy …

A Subject-Specific Multiscale Model Of Transcranial Magnetic Stimulation, Brian Daniel Goodwin

Dissertations (1934 -)

Transcranial magnetic stimulation (TMS) is a neuromodulation technique used to treat a variety of neurological disorders. While many types of neuromodulation therapy are invasive, TMS is an attractive alternative because it is noninvasive and has a very strong safety record. However, clinical use of TMS has preceded a thorough scientific understanding: its mechanisms of action remain elusive, and the spatial extent of modulation is not well understood. We created a subject-specific, multiscale computational model to gain insights into the physiological response during motor cortex TMS. Specifically, we developed an approach that integrates three main components: 1) a high-resolution anatomical MR …

Flux-Weakening Control For Permanent-Magnet Synchronous Motors Based On Z-Source Inverters, Muyang Li

Master's Theses (2009 -)

Permanent magnet synchronous machines (PMSMs) have high efficiency, high power density, high torque-to-inertia ratio, and fast dynamic response. These features make this kind of machines very attractive for electric vehicle (EV) applications. However, because of their nature, i.e., constant magnet flux provided by magnets, these machines have a narrow constant power speed range (CPSR). This limitation is a strong drawback for application of PMSMs in electric vehicles, where high speed is the top requirement. Two different approaches can extend the maximum speed under constant power: (1) Increasing a drive's output voltage, and (2) implementing flux-weakening (FW) control methods. However, a …

Kinematic Analysis Of The Glenohumeral Joint: A Comparison Of Post-Operative Rotator Cuff Repair Patients And Controls, Ryan Richard Inawat

Master's Theses (2009 -)

Rotator cuff (RC) repair is a standard surgical intervention used to alleviate pain and loss of function in the shoulder due to torn RC tendons, involving re-attachment of the tendon to the humerus. Quantitative evaluation of kinematics following RC repair is possible with video motion analysis techniques, yet is rarely performed. With the purpose of quantifying the effects of RC repair, a Vicon 524 (Oxford, UK) motion analysis system was used to investigate three-dimensional (3D) kinematics of the glenohumeral (GH) joint and thorax following supraspinatus repair. A validated, 18 marker, inverse dynamics model based on ISB standards was applied to …

Speaker Independent Acoustic-To-Articulatory Inversion, An Ji

Dissertations (1934 -)

Acoustic-to-articulatory inversion, the determination of articulatory parameters from acoustic signals, is a difficult but important problem for many speech processing applications, such as automatic speech recognition (ASR) and computer aided pronunciation training (CAPT). In recent years, several approaches have been successfully implemented for speaker dependent models with parallel acoustic and kinematic training data. However, in many practical applications inversion is needed for new speakers for whom no articulatory data is available. In order to address this problem, this dissertation introduces a novel speaker adaptation approach called Parallel Reference Speaker Weighting (PRSW), based on parallel acoustic and articulatory Hidden Markov Models …

Characterization Of Bone Material Properties And Microstructure In Osteogenesis Imperfecta/Brittle Bone Disease, John Robert Jameson

Dissertations (1934 -)

Osteogenesis imperfecta (OI) is a genetic disorder primarily associated with mutations to type I collagen and resulting in mild to severe bone fragility. To date, there is very little data quantifying OI cortical bone mechanics. The purpose of this dissertation was to investigate bone microstructure, mineralization, and mechanical properties in adolescents with OI. Characterization studies were performed on small osteotomy specimens obtained from the extremities during routine corrective surgeries. Nanoindentation was used to examine the longitudinal elastic modulus and hardness at the material level for mild OI type I vs. severe OI type III. Both modulus and hardness were significantly …

Neuromodulation For Depression: Insights Gained From Neuroimaging And Computational Models, Yagna Pathak

Dissertations (1934 -)

Major depressive disorder (MDD) is a public health concern worldwide, affecting a sixth of the American population. Neuromodulation therapies have been employed to treat severe cases of treatment resistant depression. These procedures attempt to modulate activity in cortical regions that represent nodes in brain circuits believed to be involved in MDD. One challenge in neuromodulation trials has been the difficulty in quantifying outcome variability. We sought to understand the effects of neuromodulation therapies and their sources of variability while adding an objective perspective to assess clinical improvement in neuropsychiatric disorders such as depression. The goal of my dissertation was to …

Nanogap Device: Fabrication And Applications, Jun Hyun Han

Dissertations (1934 -)

A nanogap device as a platform for nanoscale electronic devices is presented. Integrated nanostructures on the platform have been used to functionalize the nanogap for biosensor and molecular electronics. Nanogap devices have great potential as a tool for investigating physical phenomena at the nanoscale in nanotechnology. In this dissertation, a laterally self-aligned nanogap device is presented and its feasibility is demonstrated with a nano ZnO dot light emitting diode (LED) and the growth of a metallic sharp tip forming a subnanometer gap suitable for single molecule attachment.

For realizing a nanoscale device, a resolution of patterning is critical, and many …

Surface Acoustic Wave (Saw)-Based Gas Flow Sensor, Nisar Ahmad

Dissertations (1934 -)

There has been a growing interest in using SAW devices for sensing various physical parameters such as pressure, acceleration, temperature, and gas. The current research has been undertaken to derive a model of a SAW-based gas flow rate sensor, using the principle of heat transfer with the flow of gas. It consists of a SAW delay line fabricated on a suitable substrate and a thin film heater to heat the SAW device to a suitable temperature above the ambient. The delay line is connected in the feedback loop of an rf-amplifier resulting in a delay line stabilized SAW oscillator. When …

Modeling, Analysis, And Verification Of A Weld-Breaking Mechanism For Automatic Circuit Recloser Applications, Brian Korves

Master's Theses (2009 -)

The automatic circuit recloser (ACR) is responsible for protecting electrical distribution grids in the event that high voltage power lines come in contact with ground. In order to prevent damage, ACRs break the electrical continuity of the circuit through the use of a vacuum interrupter and a weld breaking mechanism. Vacuum interrupters consist of two metallic contacts in an air-tight ceramic housing. Due to the electrical interactions that take place during the interruption process, unintended welds are formed between the contacts. These welds have the ability to impede or completely stop the interruption process, thus rendering the ACR inoperable. In …

An Experimental Fatigue And Finite Element Study Of A Welded Joint Of A Snowplow Blade, George Ernest Selburg

Master's Theses (2009 -)

This study describes a method to evaluate the fatigue life of a welded joint of a snowplow. Fatigue specimens were then fabricated, which simulated the joint and its loading characteristics. The joint in the specimens were characterized by measuring the geometry of the weld and the hardness of the parent material, weld material, and heat affected zone. It was determined that the fatigue crack that developed in the joint was exposed to mode I fracture forces in the normal plane of the crack. The specimens were then tested in a hydraulic closed looped system to determine the mechanism of fatigue …

Analysis Of Sensor Signals And Quantification Of Analytes Based On Estimation Theory, Karthick Sothivelr

Master's Theses (2009 -)

Compact sensor systems for on-site monitoring of groundwater for trace organic compounds are currently under development. To permit near real-time analysis of samples containing multiple analytes, the present work investigates a sensor signal processing approach based on estimation theory, specifically using Kalman Filter and Extended Kalman Filter. As a first step towards the analysis of groundwater samples containing multiple compounds, the approach presented in this work permits estimation of analyte concentration(s) in binary mixtures and single analyte samples on-line, before the sensor response reaches steady-state. Sensor signals from binary mixtures and single analyte samples of BTEX compounds (benzene, toluene, ethylbenzene, …

Design And Verification Of A Compact Variable Stiffness Actuator With A Very Large Range Of Stiffness, Daniel Garces

Master's Theses (2009 -)

Current conventional robots require high stiffness joints to provide absolute positioning accuracy in free space which also causes problems when operating in constrained space. To circumvent these problems, Variable Stiffness Actuators (VSAs) can be used to vary their stiffness to suit the task being performed. A new VSA was designed to provide a very large range of stiffness in a compact size. The Arched Flexure VSA uses a cantilevered beam acting as the flexure with a variable point of contact. It allows the joint to have continuous variable stiffness, have zero stiffness for a small range of motion, and rapid …

Analysis Of The Detection Of Organophosphate Pesticides In Aqueous Solutions Using Polymer-Coated Single Idt Sensors, Michael J. Mccarthy

Master's Theses (2009 -)

The single interdigital transducer (IDT) device was investigated as a micro-chemical sensor for the detection of organophosphates compounds in aqueous solutions. The compounds of interest are: parathion, parathion-methyl, and paraoxon. The polymers used as a partially-selective coating for the direct detection of these compounds are 2,2'-diallylbisphenol A- 1,1,3,3,5,5-hexamethyltrisiloxane (BPA-HMTS) and polyepichlorohydrin (PECH). BPA-HMTS is synthesized here at Marquette University. The measurement of interest for the single IDT is the change radiation resistance. The radiation resistance represents the energy stored in the propagating acoustic wave. As analyte absorbs into the polymer coating, changes in the film's properties will undergo resulting in …

Design Of A Passive Ankle Prosthesis With Powered Push-Off Using A Cam Timing Mechanism, Jacob J. Rice

Master's Theses (2009 -)

This thesis presents the design and simulation results of the CamWalk, a novel passive prosthetic ankle that has mechanical behavior similar to that for a natural ankle. The CamWalk uses a compression spring network that allows coupling between two degrees of freedom; one for translation along the leg and another for rotation about the ankle joint. When walking, potential energy from the person's weight is stored in the spring network in deflection along the leg. The energy is released by the network as rotation of the foot. The amount of translational work that is converted to rotational work about the …

Determination Of A Predictive Stiffness Model For A 1 Dof Human Inspired Robotic Joint, Michael Boyarsky

Master's Theses (2009 -)

In order to facilitate more natural and intuitive interaction for human users, robots need to move in a more human-like manner as compared to current robots. This change would enable humans to better anticipate robot movements (which would allow humans to better avoid collisions if necessary) and also improve safety in the context of a collision between a robot and a human. The goal of this thesis was to analyze experimental data of human motion to gain an understanding of how human motion and robot motion differ. From this understanding, a neuro-motor model (NMM) of a human elbow (previously established …

Automated Selection Of The Optimal Cardiac Phase For Single-Beat Coronary Ct Angiography Reconstruction, Daniel Stassi

Master's Theses (2009 -)

This thesis investigates an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. Reconstructing a low-motion cardiac phase improves coronary artery visualization in coronary CT angiography (CCTA) exams. Currently, standard end-systole and/or mid-diastole default phases are prescribed or alternatively, quiescent phases are determined by the user. As manual selection may be time-consuming and standard locations may be suboptimal due to patient variability, an automated method is investigated. An automated algorithm was developed to select the optimal phase based on quantitative image quality (IQ) metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated …

The Effects Of Organ-Based Tube Current Modulation On Radiation Dose And Image Quality In Computed Tomography Imaging, Diksha Gandhi

Master's Theses (2009 -)

The purpose of this thesis was to quantify dose and noise performance of organ-dose-based tube current modulation (ODM) through experimental studies with an anthropomorphic phantom and simulations with a voxelized phantom library. Tube current modulation is a dose reduction technique that modulates radiation dose in angular and/or slice directions based on patient attenuation. ODM technique proposed by GE Healthcare further reduces tube current for anterior source positions, without increasing current for posterior positions. Axial CT scans at 120 kV were performed on head and chest phantoms (Rando Alderson Research Laboratories, Stanford, CA) on an ODM-equipped scanner (Optima CT660, GE Healthcare, …

Failure Mechanisms And Key Parameters Of Frp Debonding From Cracked Concrete Beams, Tayyebeh Mohammadi

Dissertations (1934 -)

Intermediate crack (IC) induced debonding failure of Fiber Reinforced Polymer (FRP)-strengthened reinforced concrete beams starts at the tip of flexural/shear cracks within the shear span and propagates towards the FRP plate termination. In this study, experimental and numerical programs are performed to characterize and predict the failure mechanisms of IC debonding failure, and identify the key parameters affecting such failure. It is found that the bond-slip relation obtained from the pullout test does not represent the bond-slip relation of the FRP/concrete interface in the FRP-strengthened concrete beams, and it cannot be directly used for predicting the load capacity of the …

Analysis Of Power Converter's Control Techniques In Grid-Tie And Ac Micro/Smart Grid, Abdulgafor Mohammed Alfares

Master's Theses (2009 -)

Power converters have an outstanding potential in micro and smart grid applications that require flexible and fast power control as well as rigid voltage regulation at the point of common coupling. Power converters are required to properly operate under several modes of operation such as grid-tie and micro-grid modes of operations. In addition, the control system should be designed to enable proper load sharing between several units. Several control techniques have been proposed in the literature to address most of the control requirements of the power converters under different operating modes mentioned above. However, references found in the literatures are …

Computational Evaluation Of Shear Stress And Restenosis In Stented Coronary Arteries Using Optical Coherence Tomography, Joshua K. Hughey

Master's Theses (2009 -)

The cause of coronary artery neointimal thickness (NT) leading to restenosis in ~10% of drug-eluting stents (DES) is unknown, but adverse wall shear stress (WSS) may contribute. Prior studies comparing WSS to restenosis for first generation DES yielded conflicting results, and cited different mechanisms of action for DES agents. Studies to date have not accounted for stent geometry, which dictates local WSS patterns influencing drug concentration. The objective of this investigation was to evaluate current generation stent platforms via their WSS patterns and their respective impact on NT. We prospectively enrolled 19 patients, who were randomized to thin-strut (81μm) 2-link …

Markerless Analysis Of Upper Extremity Kinematics During Standardized Pediatric Assessment, Jacob R. Rammer

Master's Theses (2009 -)

Children with hemiplegic cerebral palsy experience reduced motor performance in the affected upper extremity and are typically evaluated based on degree of functional impairment using activity-based assessments such as the Shriners Hospitals for Children Upper Extremity Evaluation (SHUEE), a validated clinical measure, to describe performance prior to and following rehabilitative or surgical interventions. Evaluations rely on subjective therapist scoring techniques and lack sensitivity to detect change. Objective clinical motion analysis systems are an available but time-consuming and cost-intensive alternative, requiring uncomfortable application of markers to the patient. There is currently no available markerless, low-cost system that quantitatively assesses upper extremity …

Using Evolutionary Programming To Increase The Accuracy Of An Ensemble Model For Energy Forecasting, James Gramz

Master's Theses (2009 -)

Natural gas companies are always trying to increase the accuracy of their forecasts. We introduce evolutionary programming as an approach to forecast natural gas demand more accurately. The created Evolutionary Programming Engine and Evolutionary Programming Ensemble Model use the current GasDay models, along with weather and historical ow to create an overall forecast for the amount of natural gas a company will need to supply to their customers on a given day. The existing ensemble model uses the GasDay component models and then tunes their individual forecasts and combines them to create an overall forecast. The inputs into the Evolutionary …

A One-Dimensional Model Of A Closed-Loop Refrigeration Test Block For Centrifugal Compressors, Paul D. Gessler

Master's Theses (2009 -)

The increasingly competitive building equipment and control industry pushes manufacturers to continually improve the performance and efficiency of their products to develop and maintain a competitive edge. Compressor development is an expensive endeavor, but the cost and time required for testing can be minimized by developing a model of the compressor test block to predict its behavior with a given prototype compressor at specified operating conditions. This thesis presents a thermodynamic model of a hot gas bypass test block used to evaluate centrifugal compressor performance at a compressor development facility. The test block uses cooling towers to reject the heat …

Blending As A Multi-Horizon Time Series Forecasting Tool, Tian Gao

Master's Theses (2009 -)

Every day, millions of cubic feet of natural gas is transported through interstate pipelines and consumed by customers all over the United States of America. Gas distributors, responsible for sending natural gas to individual customers, are eager for an estimate of how much natural gas will be used in the near future. GasHour software, a reliable forecasting tool from the Marquette University GasDay lab, has been providing highly accurate hourly forecasts over the past few years. Our goal is to improve current GasHour forecasts, and my thesis presents an approach to achieve that using a blending technique. This thesis includes …

The Derivation Of Euler's Equations Of Motion In Cylindrical Vector Components To Aid In Analyzing Single Axis Rotation, James J. Jennings

Master's Theses (2009 -)

The derivation of Euler's equations of motion in using cylindrical vector components is beneficial in more intuitively describing the parameters relating to the balance of rotating machinery. Using the well established equation for Newton's equations in moment form and changing the position and angular velocity vectors to cylindrical vector components results in a set of equations defined in radius-theta space rather than X-Y space. This easily allows for the graphical representation of the intuitive design parameters effect on the resulting balance force that can be used to examine the robustness of a design. The sensitivity of these parameters and their …

Plastic Deformation Investigation Of High Energy Input Friction, Tao Yan

Dissertations (1934 -)

In this dissertation, plastic deformation of friction surfaces under high energy input is investigated. The plastic deformation of the friction surface and subsurface was studied and models were established to estimate deformation.

In order to calculate the plastic deformation at friction surface, an algorithm based on Ramberg-Osgood relationship was generated, and a single material model was developed based on this algorithm. Work hardening caused by plastic deformation and thermal softening caused by elevated temperature were considered in the model. To validate the model, an apparatus was designed to perform friction tests under different conditions. A special steel specimen with a …