e-Publications@Marquette

Black Women and Long Struggle for Racial, Gender and Economic Justice, 1969 to 2019

Barbara Ransby — Thu, 04 Apr 2019 12:00:00 PDT

Discussion with historian, writer and longtime activist Barbara Ransby on "Black Women and Long Struggle for Racial, Gender and Economic Justice, 1969 to 2019". Barbara Ransby is an historian, writer and longtime activist. She is a Distinguished Professor of African American Studies, Gender and Women's Studies, and History at the University of Illinois at Chicago (UIC) where she directs the campus-wide Social Justice Initiative. She is author of the highly acclaimed biography, Ella Baker and the Black Freedom Movement: A Radical Democratic Vision, which received eight national awards and recognitions. She is also the author of Eslanda: The Large and Unconventional Life of Mrs. Paul Robeson (Yale University Press, January 2013) and, most recently, Making All Black Lives Matter: Reimagining Freedom in the 21st Century (University of California Press, 2019).

Hosted by the Marquette Forum, Raynor Memorial Libraries, Office of Institutional Diversity and Inclusion, History Department, CURTO, Institute for Women's Leadership and Center for Gender and Sexuality Studies.

Frances Wright : her social thought as found in her moral philosophy

Michaele Datsko — Tue, 23 Apr 2019 09:22:41 PDT

Quantifying Hemodynamic Changes Caused by Stenting of Coronary Bifurcation Lesions Using Realistic Computational Fluid Dynamics Models

Andrew R. Williams — Mon, 22 Apr 2019 16:58:20 PDT

One-third of deaths in the United States are caused by cardiovascular disease and coronary artery disease (CAD) accounts for 52% of these deaths. Interestingly, CAD often localizes at bends, branches and bifurcations throughout the vasculature. Stenting is the preferred treatment for CAD and has been applied to coronary bifurcation lesions with limited success due to high levels of restenosis. Hemodynamic parameters including time-averaged wall shear stress (TAWSS) and oscillatory shear.index (OSI) correlate with restenosis but are not easily measured clinically. Computational fluid dynamics (CFO) is a simulation technique utilizing clinical data, making it well-suited for studying hemodynamics in stented coronary bifurcations. The objective of this work is to develop methods whereby geometric models of stented coronary bifurcations can be created and simulated with CFO using realistic boundary conditions. Initially, idealized models were generated to quantify hemodynamics after stenting the main branch and following post-stenting side branch balloon dilation since these procedures cause pronounced changes in the location of the bifurcation blood flow divider (i.e. carina). The first patient-specific models of stented coronary bifurcations to date were then conducted to quantify altered hemodynamics with increased physiologic realism. Lastly, methods of expanding a simple stent model using finite element analysis (FEA) were implemented for future use with more complex bifurcation stenting techniques. Stenting increased distal main branch diameter causing skewing of the velocity profile and high TAWSS towards the carina in idealized models, while also introducing eccentric regions of low TAWSS along the opposing lateral wall. Post-stenting side branch balloon dilation restored the carina to its native position thereby alleviating a partial stenosis introduced by stenting, but resulted in concentric regions of low TAWSS and high OSI in the distal main branch. Areas of low TAWSS were observed near stent struts in all simulations, consistent with previous work. Importantly, decreased TAWSS and increased OSI have been shown to correlate with restenosis. Therefore, the current results may partially explain why restenosis rates remain high in stented bifurcation lesions, and be amenable to improved bifurcation stent designs. Future work will leverage the methods and initial FEA developments of this work for this purpose.

Investigation of High-Field Non-Ohmic Behavior in Piezoelectric Semiconducting Zinc Oxide

Thomas E. Wilbricht — Mon, 22 Apr 2019 16:58:09 PDT

Reproducible current saturation and current oscillations in piezoelectric semiconducing single crystal UHP Zinc Oxide over the temperature range from 300°K to 77°K has been experimentally observed. Through the concept of electron-acoustic wave interactions in piezoelectric ZnO, theoretical verification of the experimentally observed phenomena is presented . A new concept is introduced which predicts whether or not a particular crystal of ZnO will generate current instabilities at room temperature.

Flexural Behavior of Reinforced and Prestressed Concrete Beams Using Finite Element Analysis

Anthony J. Wolanski — Mon, 22 Apr 2019 16:57:54 PDT

Several methods have been utilized to study the response of concrete structural components. Experimental based testing has been widely used as a means to analyze individual elements and the effects of concrete strength under loading. The use of finite element analysis to study these components has also been used. This thesis is a study of reinforced and prestressed concrete beams using finite element analysis to understand their load-deflection response. A reinforced concrete beam model is studied and compared to experimental data. The parameters for the reinforced concrete model were then used to model a prestressed concrete beam. Characteristic points on the load-deformation response curve predicted using finite element analysis were compared to theoretical (hand-calculated) results. Conclusions were then made as to the accuracy of using finite element modeling for analysis of concrete. The results compared well to experimental and hand calculated.

A Study of the Effects of Earthen Attenuation Devices in Reducing Noise and Improving Privacy in Neighborhoods Adjacent to Urban Freeways

Neil R. Wienser — Wed, 17 Apr 2019 15:56:37 PDT

The use of earth berms as a method of attenuating highway noise pollution into adjacent residential neighborhoods has become more prevalent throughout the country. In the summer of 1972 the Wisconsin Division of Highways constructed their first sound attenuation earth berms along I-94 in Milwaukee and Waukesha Counties. The purpose of this paper is to not only assess the measured and calculated attenuations obtained from the sound berms but also to assess the perceived effects of the berms on the adjacent residential neighborhoods by means of an attitudinal survey. In addition, the measured attitudinal survey and general recommendations are made as to the future use of sound barriers. Simultaneous sound level readings were taken at four points along sound sample lines located across the alignments of all proposed sound berms. The points were located in front of the future berm, at the right-of-way fence, and at two varying distances from the fence. The sound readings were taken before and after the construction of the berms. The attenuations attributed to the berms were computed as the differences in attenuations observed between the point in front of the berm and all the other points along the sound sample lines. It was found that the berms resulted in median sound level attenuations of 5 dBA at the right-of-way line and 3 dBA at a distance corresponding to the front sidewalk at the homes alone the freeway. The same attenuations calculated on the basis of the standard procedure discussed in the NCHRP Report No. 117 generally matched the measure values...

Liquid Flowmeter Using Thermal Measurement; Design and Application

Woojae Chung — Wed, 17 Apr 2019 13:49:59 PDT

This thesis presents flowmeter devices which can measure flowrate, pressure and temperature offlowing liquid samples using thermal measurement method. Typical thermal mass flowmeter usesthermal properties of materials to obtain flow features only for gases. We designed and fabricatedflowmeter devices with various functionalities such as: measuring properties of flowing liquid andidentifying the type of liquid samples.Thermal measurement methods using temperature sensor is a key of our flowmeter’s workingprinciple. The thermal mass flowmeter consists of a glass capillary, a tungsten wire heater, and aresistance temperature detector (RTD) sensor. The heater and sensors are integrated on the surface ofthe glass capillary. Noncontact flow measurement between sensor and liquid sample prevents flowdisturbance and corrosion of sensors. When robustness and sensitivity are required for flowmeasurement, the thermal mass time of flight (ToF) measurement method, along with its simplereadout, make it a great candidate for industrial and vehicle applications. The heat traveling timemeasurement is the method that measures the time of flight of thermal mass from heating site tosensing site. Depending on the flowrate of fluid and thermal diffusivity of the liquid sample, the heattraveling time differs.However, low response speed and low sensitivity characteristics are drawbacks of thermalmeasurement methods, which are influenced by thermal properties of materials and structural design.To increase sensitivity of our flowmeter, we fabricated and designed the device using differentcomponent variables such as: size and thickness of RTD sensors, heating element, and glass tubethickness. Also, the flowmeter introduced in this work has two different types based on their size andthey enable large flow range measurement. Micro-flowmeter can measure flowrate less than 100μl/min and macro-flowmeter measures flowrate from 1 to 10 gallon per minute (GPM) of deionized(DI) water.In this work, we used a number of techniques to increase the functionality of our device. Bypasssystem enables to measure high range of flowrate. Also, we designed gravity-driven flowratecalibration system to generate accurate flowrates. Moreover, we developed flowrate monitoringsystem to improve the performance of calibration system.

Correlations Between Shoulder Rotational Motion, Strength Measures and Throwing Biomechanics in Collegiate Baseball Pitchers

Austin William Higgins — Wed, 17 Apr 2019 13:49:50 PDT

Pitching involves high stresses to the arm that may alter soft tissue responsible for controlling biomechanics. It has been hypothesized that imbalances in strength and flexibility of the dominant shoulder lead to decreased performance and increased injury risk, but it is not fully known what specific pitching biomechanics are altered. There is a critical need to determine correlations between shoulder rotational strength, range of motion and pitching kinetics. Without such knowledge, identifying potential for injury from shoulder imbalances will likely remain difficult and invasive. The goal of this study was to determine correlations between shoulder rotational strength and range of motion and kinetics. Twelve collegiate pitchers participated in this IRB approved study. The clinical measures session tested shoulder rotational range of motion and strength and grip strength. The motion analysis session tested pitching biomechanics. Paired t-tests investigated differences in strength and range of motion between arms. Linear regression was performed to determine correlations between clinical measures, kinetics and pitch velocity. Regression learner neural networks were created to predict pitch velocity and elbow varus torque using clinical measures as inputs. The dominant arm had significantly higher external rotation and total range of motion than the nondominant arm. The nondominant arm normalized external rotation peak torque was significantly greater than the dominant arm at 0˚ external rotation. Correlations were found between elbow varus torque and isometric external/internal rotation ratio, and between shoulder posterior shear force and isokinetic eccentric external rotation/internal rotation ratios. Correlations to velocity included grip strength, concentric external rotation peak torque, isometric internal rotation peak torques, and isometric external rotation peak torques. The neural network accurately predicted velocity, with the standard deviation of the error equal to 2.29 (2.97%). These correlations associate two testing methods to identify injury risk. Increasing external/internal rotation ratios may decrease elbow varus torque and shoulder posterior shear force. Increasing external rotation, internal rotation, and grip strength may lead to velocity gains. Velocity can be predicted using clinical measures and a neural network.

Ergonomics Study of a Helmet-Mounted Augmented Reality System for Coal Power Plant Workers

Ashley M. Toll — Wed, 17 Apr 2019 13:49:43 PDT

Augmented reality (AR) is a technology that combines real and virtual information presented to the user in an interactive way in real time. The Microsoft HoloLens and RealWear HMT-1 are two common types of head-mounted AR available to industrial field workers. These two AR systems were tested on how they affected indicators of eye strain and forces of the neck and shoulder muscles for electric utility power plant operators while they performed five routine inspection tasks using coal burning equipment. The inspection tasks were conducted under three conditions: HoloLens, HMT-1, and absence of AR (normal). The duration of the inspection tasks ranged from an average of 10 to 28 s. Twelve experienced power plant operators participated in the study. Surface electromyography (sEMG) of the right and left sternocleidomastoid, splenius, semispinalis capitis, and upper trapezius muscles were measured, and a small camera recorded blink rate of the right eye. Results show there were generally no significant differences in 50th and 90th percentile sEMG between the three conditions for all eight muscles. Although blink rate did not vary significantly between the experimental conditions, a trend appeared that showed average HoloLens blink rate lower than the HMT-1 and No AR (~ 4.5 blinks/min;28% decrease). Lower blink rate is a risk factor of eye strain, and data from this experiment suggest that the HoloLens may cause eye strain. Longer durations of sustained HoloLens usage must be tested to determine whether the HoloLens presents risk of eye strain to electric utility field workers.

The Characterization of Char Particle Morphology and Its Effects on Combustion

Scott Jorgensen — Wed, 17 Apr 2019 13:49:35 PDT

Char particle combustion typically occurs under internal diffusion control, which results in inter-particle reactant gradients. Reactant concentrations throughout the char’s carbon structure must be known in order to predict overall particle reaction rates. These concentrations can be predicted by analytical models; however, effects of char morphology are typically ignored within these simplified models. In order to incorporate these effects, the morphology of Illinois coal #6 was studied by visualizing their structure in three-dimensions through the use of micro-computed tomography. Morphological characteristics of macro-porosity, macro-porosity location, and wall thickness were then measured for the sampled char particles. The sampled char particles morphology was cenospheric with a wall thickness that could be reasonably predicted using the particle’s macro-porosity and size. A theoretical concentration model, termed hollow sphere model, was developed based on this cenosphere morphology. The effects morphology has on char combustion were then shown by comparing the oxygen concentration and temperature profiles obtained from three dimensional CFD simulations, where three distinct particles were considered. CFD results were compared with two theoretical concentration models for the three particles to determine their accuracy. The hollow sphere model more accurately predicted reactant concentration within the char particles due to its incorporation of morphological effect.

Kinetic Analysis of Biosolid Pyrolysis

William Regan Kreutter — Wed, 17 Apr 2019 13:49:28 PDT

Waste reduction and energy recovery have been an environmental focus. Many of these solutions involve the thermal degradation of waste, such as household garbage or organic waste. To help reduce the negative environmental impact associated with processes like incineration, methods have been developed to utilize the carbonaceous material and energy contained in waste. Wastewater treatment plants are responsible for collecting and cleaning billions of gallons of sewage and stormwater each year. The water collected goes through multiple cleaning stages before being discharged into surface water. Sewage sludge, commonly referred to as biosolids, are produced during the process. Biosolids are carbon rich particles that can be used as fertilizers. The city of Milwaukee dries its biosolids and sells them as a fertilizer called Milorganite®. Pyrolysis is a thermochemical process which involves heating an organic material in an inert atmosphere to produce gases and a char residue. Applying pyrolysis to biosolids reduces the volume of waste to be landfilled and yields three products, including high-heating value light gases (py-gas) and a carbon rich porous char (biochar) that works well as a fertilizer, similar to dried biosolids. Pyrolysis of locally-produced dried biosolids will be studied in this thesis. Thermogravimetric analysis (TGA) is an experimental technique used to study thermal decomposition reactions, such as pyrolysis, by measuring the mass of a sample as a function of temperature and time. In this study, non-isothermal TGA has been used to study the pyrolysis kinetics of Milorganite®. The kinetic parameters are essential for sizing reactors to optimize the pyrolysis process. Pyrolysis of dried biosolids is modeled as a combination of independent parallel reactions. Thermogravimetric (TG) and differential thermogravimetric (DTG) data were used with a nonlinear model-fitting method to determine the activation energy, pre-exponential factor, and fractional contribution for the five major pseudo-components found in the dried biosolid. In contrast with the few existing studies using model-fitting approaches for biosolid pyrolysis kinetics, this study first fits the kinetic parameters to TG data, then employs the results as initial guesses for a second fitting process to DTG data. This technique makes for a smoother convergence process in reducing the residual between fitted and experimental data. More importantly, this study performed the fitting process for a wide range of initial guesses and found that the solver converged to the same set of kinetic parameters for 95% of the initial guesses, inspiring confidence that the kinetic parameters correspond to a global, rather than a local, minimum.

Development of a Quasi-Monte Carlo Method for Thermal Radiation

Joseph Farmer — Wed, 17 Apr 2019 13:49:20 PDT

Radiative heat transfer in participating media is among the most challenging computational engineering problems due to the complex nonlinear, nonlocal nature of radiation transport. Many approximate methods have been developed in order to resolve radiative heat transfer in participating media; but approximate methods, by the nature of their approximations, suffer from various shortcomings both in terms of accuracy and robustness. The only methods that can resolve radiative transfer accurately in all configurations are the statistical Monte Carlo-based methods. While the Monte Carlo (MC) method is the most accurate method for resolving radiative heat transfer, it is also notoriously computationally prohibitive in large-scale simulations. To overcome this computational burden, this study details the development of a quasi-Monte Carlo (QMC) method for thermal radiation in participating media with a focus on combustion-related problems. The QMC method employs a low-discrepancy sequence (LDS) in place of the traditional random number sampling mechanism used in Monte Carlo methods to increase computational efficiency. In order to analyze the performance of the QMC method, a systematic comparison of accuracy and computational expense was performed. The QMC method was validated against formal solutions of radiative heat transfer in several one-dimensional configurations and extended to three practical combustion configurations: a turbulent jet flame, a high-pressure industrial gas turbine, and a high-pressure spray combustion chamber. The results from QMC and traditional Monte Carlo are compared against benchmark solutions for each case. It is shown that accuracy of the predicted radiation field from QMC is comparable to MC at lower computational costs. Three different low-discrepancy sequences – Sobol, Halton, and Niederreiter – were examined as part of this work. Finally, recommendations are made in terms of choice of the sequence and the number of the dimensions of the LDS for combustion-relevant configurations. In conclusion, significant improvements in computational costs and accuracy seen in the QMC method makes it a viable alternative to traditional Monte Carlo methods in high-fidelity simulations.

Functional Singular Spectrum Analysis and the Clustering of Time-Dependent Data

Jordan Trinka — Wed, 17 Apr 2019 08:22:19 PDT

The present work extends the application of the recently submitted functional singular spectrum analysis (FSSA) into the realm of structure level subsequence clustering. We begin with a comprehensive review of principal component analysis (PCA), functional principal component analysis (FPCA), singular spectrum analysis (SSA), and the recently submitted FSSA. We computationally show that the novel FSSA-FPCA hybrid clustering technique can be employed as an effective structure-based subsequence clustering method for call-center functional time series data where the method behaves as a dimension reduction technique for time-dependent data. Metrics, such as the F-ratio from k-means clustering, the w-correlation between reconstructed functional time series, and the Rand index are offered to determine the quality of clustering results of labeled functional data. We find that these outcomes are dependent on the grouping stage of FSSA for the call-center data. We also find that our measurements are not significantly sensitive to changes in groupings. Our investigations show that FSSA behaves as a type of temporal to frequency domain transformation similar to that of a Fourier analysis. The results shown in the present essay can be used to extend FSSA in its maturation and offer insight into how the hybrid method should be used and the challenges one faces with it.