Digital Commons Network^™

Mechanical Property Development And Numerical Modeling Of Ultra-High Performance Concrete Focused On Isothermal Curing Conditions, Thomas Allard

Theses and Dissertations

Ultra-high performance concrete (UHPC) has progressively gained interest because of its favorable strength and durability properties. Literature shows that curing temperature has a significant effect on the resultant mechanical properties of UHPC, generally resulting in increased compressive strength. However, limited datasets are currently available to ascertain the degree of change related to compressive strength as a function of curing temperature and conditions. This study investigates the effect of isothermal and submerged curing temperature conditions, ranging from 10°C to 90°C, on the compressive strength and elastic modulus development of UHPC and generates a numerical model to capture these effects. The extent …

Micromechanics: Crystal Plasticity Links For Deformation Twinning, Yub Raj Paudel

Theses and Dissertations

Historically, the ability of crystal plasticity to incorporate the Schmid’s law at each integration point has been a powerful tool to simulate and predict the slip behavior at the grain level and the succeeding heterogeneous stress/strain localization and texture evolution at the macroscopic level. Unfortunately, this remarkable capability has not been replicated for materials where twinning becomes a noticeable deformation mechanism, namely in the case of low-stacking fault energy cubic, orthorhombic, and hexagonal close packed structures. This dissertation is an attempt to gain understanding on the heterogeneous deformation due to twinning through various techniques including micromechanics, discrete dislocation dipole loops, …

Models And Algorithms To Solve Electric Vehicle Charging Stations Designing And Managing Problem Under Uncertainty, Md Abdul Quddus

Theses and Dissertations

This dissertation studies a framework in support electric vehicle (EV) charging station expansion and management decisions. In the first part of the dissertation, we present mathematical model for designing and managing electric vehicle charging stations, considering both long-term planning decisions and short-term hourly operational decisions (e.g., number of batteries charged, discharged through Battery-to-Grid (B2G), stored, Vehicle-to-Grid (V2G), renewable, grid power usage) over a pre-specified planning horizon and under stochastic power demand. The model captures the non-linear load congestion effect that increases exponentially as the electricity consumed by plugged-in EVs approaches the capacity of the charging station and linearizes it. The …

Modification Of Training Methods And Alarm Thresholds: Two Ways To Reduce Potential Hazardous Clinical Alarm Related Incidents, Manikantan Shanmugham

Theses and Dissertations

Within the healthcare system, nurses, are involved in many critical steps of the patient care process such as surgery triaging, post-procedure recovery monitoring and handoff release to a caregiver. A significant portion of their time is spent on the hospital floors where patients recover from their medical procedures. In today’s healthcare environments, multiple devices – typically monitors, ventilators, and infusion pumps – are used during said patient recovery process. Health equipment manufacturers often add alarms to medical devices, which serve a variety of purposes, ranging from simple notifications to warnings and alerts about potential hazards that require rapid action. In …

Numerical Study And Investigation Of A Gurney Flap Supersonic Nozzle, Mohammed El Mellouki

Theses and Dissertations

Flow separation is a common fluid dynamics phenomenon that occurs within supersonic nozzles while operating at off-design pressures. Typically, off-design pressures result in a shock formation that leads to a non-uniformity of the exiting flow and creates flow separation and flow recirculation. So far, no effective solution has been presented to eliminate flow separation and increase the total performance of the nozzle. The purpose of this work is to investigate whether a Gurney flap may beneficially affect the exiting flow pattern. For a better understanding of the Gurney flap effect, this investigation used a supersonic nozzle geometry based on a …

Finite Nuclei In Covariant Density Functional Theory: A Global View With An Assessment Of Theoretical Uncertainties, Sylvester E. Agbemava

Theses and Dissertations

Covariant density functional theory (CDFT) is a modern theoretical tool for the description of nuclear structure phenomena. Different physical observables of the ground and excited states in even-even nuclei have been studied within the CDFT framework employing three major classes of the state-of-the-art covariant energy density functionals. The global assessment of the accuracy of the description of the ground state properties and systematic theoretical uncertainties of atomic nuclei have been investigated. Large-scale axial relativistic Hartree-Bogoliubov (RHB) calculations are performed for all Z < 106 even-even nuclei between the two-proton and two-neutron drip lines. The sources of theoretical uncertainties in the prediction of the two-neutron drip line are analyzed in the framework of CDFT. We concentrate on single-particle and pairing properties as potential sources of these uncertainties. The major source of these uncertainties can be traced back to the differences in the underlying single-particle structure of the various CEDFs. A systematic search for axial octupole deformation in the actinides and superheavy nuclei with proton numbers Z = 88 - 126 and neutron numbers from two-proton drip line up to N = 210 has been performed in CDFT. The nuclei in the Z ~ 96, N ~ 196 region of octupole deformation have been investigated in detail and their systematic uncertainties have been quantified. The structure of superheavy nuclei has been reanalyzed with inclusion of quadrupole deformation. Theoretical uncertainties in the predictions of inner fission barrier heights in superheavy elements have been investigated in a systematic way. The correlations between global description of the ground state properties and nuclear matter properties have been studied. It was concluded that the strict enforcement of the constraints on the nuclear matter properties (NMP) defined in Ref. [1] will not necessary lead to the functionals with good description of ground state properties. The different aspects of the existence and stability of hyperheavy nuclei have been investigated. For the first time, we demonstrate the existence of three regions of spherical hyperheavy nuclei centered around (Z ~ 138, N ~ 230), (Z ~ 156, N ~ 310) and (Z ~ 174, N ~ 410) which are expected to be reasonably stable against spontaneous fission.

Functional Principal Component Analysis Of Vibrational Signal Data: A Functional Data Analytics Approach For Fault Detection And Diagnosis Of Internal Combustion Engines, Justin Blake Mcmahan

Theses and Dissertations

Fault detection and diagnosis is a critical component of operations management systems. The goal of FDD is to identify the occurrence and causes of abnormal events. While many approaches are available, data-driven approaches for FDD have proven to be robust and reliable. Exploiting these advantages, the present study applied functional principal component analysis (FPCA) to carry out feature extraction for fault detection in internal combustion engines. Furthermore, a feature subset that explained 95% of the variance of the original vibrational sensor signal was used in a multilayer perceptron to carry out prediction for fault diagnosis. Of the engine states studied …

Hypervelocity Impact Experimentation Of A Novel Micrometeoroid/Orbital Debris Shielding Concept Imbibed With Rheologically Characterized Shear Thickening Fluids, Justin Marshall Warren

Theses and Dissertations

Spacecraft are vulnerable to hypervelocity impacts (HVIs) from micrometeoroid/orbital debris (MMOD) while in space and must mitigate these using shielding. In this research aluminum honeycomb core sandwich panels filled with a shear thickening fluid (STF) were developed as a novel MMOD shielding concept. STFs display a marked rise in viscosity with increasing shear rate above a critical shear rate. The results of HVI experiments with impact velocities of ~4.8 km/s or ~6.8 km/s at 80oC or 21oC showed that incorporating a STF into shielding, as opposed to the STF’s liquid phase alone, can reduce damage to the core and the …

Implementation Of A Brassboard Prototype Of A Collision Avoidance System For Use In Ground Vehicles, Tyler James Hannis

Theses and Dissertations

Accidental collisions involving wheeled industrial ground vehicles can be costly to repair, cause serious (even fatal) human injury, and lead to setbacks with tight operation schedules. Reduction of vehicle collisions carries numerous safety and financial incentives. In this work, an integrated collision avoidance package is developed to reduce the number of vehicle collisions. Utilizing feedback from on-board sensing devices, a model predictive control (MPC) algorithm predicts control options and paths, then disallows drivers to accelerate and/or induces braking of the vehicle if a collision is imminent. A prototype system is developed, implemented, and tested on an industrial vehicle to mitigate …

The Effect Of Two-Dimensional Wall Deformations On Hypersonic Boundary Layer Disturbances, Jeremy David Sawaya

Theses and Dissertations

Previous experimental and numerical studies showed that two-dimensional roughness elements can stabilize disturbances inside a hypersonic boundary layer, and eventually delay the transition onset. The objective of the thesis is to evaluate the response of disturbances propagating inside a hypersonic boundary layer to various two-dimensional surface deformations of different shapes. The proposed deformations consist of a backward step, forward step, a combination of backward and forward steps, two types of wavy surfaces, surface dips or surface humps. Disturbances inside of a Mach 5.92 flat-plate boundary layer are excited by pulsed or periodic wall blowing and suction at an upstream location. …

Eigenvalue Analysis Of Timoshenko Beams And Mindlin Plates With Unfitted Finite Element Methods, Walid Arsalane

Theses and Dissertations

This thesis focuses on the development and convergence study of finite element methods for eigenvalue analysis of arbitrarily shaped domains with multi-material and material-void interfaces. Such configurations can be found in problems with evolving discontinuities and interfaces as in fluid-structure interaction or topology optimization problems. The differential equations considered in this thesis include the elliptic operator, Timoshenko beam and Mindlin plate. The compatibility conditions at the interface are weakly imposed using either Nitsche's method or Lagrange multipliers. The variational statements are derived for each case. The analysis results are benchmarked using Galerkin finite element discretization with bodyitted grids. Nitsche's method …

A Multiscale Study Of A Nickel Penetrator Striking A Copper Plate Under Very High Strain Rates, Yangqing Dou

Theses and Dissertations

The objective of this dissertation centers on gaining a better understanding of the structure - property - performance relations of nickel and copper through the advanced multiscale theoretical framework and integrated computational methods. The goal of this dissertation also includes to combine material science and computational mechanics to acquire a transformative understanding of how the different crystal orientations, size scales, and penetration velocities affect plastic deformation and damage behavior of metallic materials during high strain rate (> 103s-1) processes. A multiscale computational framework for understanding plasticity and shearing mechanisms of metallic materials during the high rate process was developed, which …

Procedural Calibration Of Haploscope Wings To Establish Accurate Focal Vergence Depth, Kristen Leigh Massey

Theses and Dissertations

This thesis project was undertaken with the intent to discover the source of a known but hitherto unexplained error in the calibration of the wings for a haploscope used in depth perception studies. The angles of the haploscope wings are used to control the vergence angle of the virtual images projected into each eye. This accounts for a strong depth cue used in AR and depth perception studies. Two experiments were devised to both display and attempt to characterize the error between the theoretical wing angles needed to cause a user's vision to verge at some focal depth and the …

Epigenetic Modifications Acetylation And Deacetylation Play Important Roles In Juvenile Hormone Action, Amit Roy, Subba Reddy Palli

Entomology Faculty Publications

Background: Epigenetic modifications including DNA methylation and post-translational modifications of histones are known to regulate gene expression. Antagonistic activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs) mediate transcriptional reprogramming during insect development as shown in Drosophila melanogaster and other insects. Juvenile hormones (JH) play vital roles in the regulation of growth, development, metamorphosis, reproduction and other physiological processes. However, our current understanding of epigenetic regulation of JH action is still limited. Hence, we studied the role of CREB binding protein (CBP, contains HAT domain) and Trichostatin A (TSA, HDAC inhibitor) on JH action.

Results: Exposure of Tribolium castaneum cells …

Clinical And Genetic Associations Of Renal Function And Diabetic Kidney Disease In The United Arab Emirates: A Cross-Sectional Study, Wael M. Osman, Herbert F. Jelinek, Guan K. Tay, Ahsan H. Khandoker, Kinda Khalaf, Wael Almahmeed, Mohamed H. Hassan, Habiba S. Alsafar

Research outputs 2014 to 2021

OBJECTIVES: Within the Emirati population, risk factors and genetic predisposition to diabetic kidney disease (DKD) have not yet been investigated. The aim of this research was to determine potential clinical, laboratory and reported genetic loci as risk factors for DKD.

RESEARCH DESIGN AND METHODS: Four hundred and ninety unrelated Emirati nationals with type 2 diabetes mellitus (T2DM) were recruited with and without DKD, and clinical and laboratory data were obtained. Following adjustments for possible confounders, a logistic regression model was developed to test the associations of 63 single nucleotide polymorphisms (SNPs) in 43 genetic loci with DKD (145 patients with …

Game Preparation Concludes On Day Four At The Camellia Bowl, Georgia Southern University

Athletics: News & Publications

• Game Preparation Concludes on Day Four at the Camellia Bowl

Borrowing From Ohiolink And Searchohio, University Of Dayton. University Libraries

University Libraries Blog Archive

When students, faculty, staff, UD retirees or friends of the library need library items that aren't in the Roesch Library catalog, they have access to millions of materials in the catalogs of academic and public libraries statewide through OhioLINK and SearchOhio.

Archeota, Fall 2018, Jennifer Castle, Sarah Thornton, Courtney Hopkins, Anna Belle Rosen, Havilah Steinman, Erin Fussell, Julieta Garcia

Archeota

This is the Fall 2018 issue of Archeota, the official publication of the SJSU SAASC

No More “Magic Aprons”: Longitudinal Assessment And Continuous Improvement Of Customer Service At The University Of North Dakota Libraries, Karlene T. Clark, Stephanie R. Walker

Librarian Publications

The University of North Dakota (UND) Libraries have developed a multi-award winning Customer Service Program (CSP) involving longitudinal assessment and continuous improvement. The CSP consists of iterative training modules; constant reinforcement of Customer Service Principles with multiple communication strategies and tools, and incentives that boost morale and foster not only compliance, but initiative-taking and innovation. The CSP became a widely adopted part of campus-wide assessment, beyond the libraries. Subsequent presentations at conferences led to multiple requests and implementation at other libraries.

Sustainably Managing Groundwater - Surface Water Interactions Within The Santa Rosa Plain Basin, Rhianna Frank

Master's Projects and Capstones

In this paper, I designed a strategy for implementation of sustainably managing groundwater-surface water interactions in the Santa Rosa Plain Basin in compliance with the requirements set forth by the Sustainable Groundwater Management Act of 2014. The research objectives for this analysis are: (1) to fully examine the requirements of the Sustainable Groundwater Management Act and the implications that implementation will have on the Santa Rosa Plain Basin, (2) to use technical data gathered regionally coupled with related policy design theory to analyze how groundwater and surface water interactions can be managed to meet the requirements set forth in this …

Sharon Nichols Joins Small Business Center As State Director, Michelle Thompson

University of Mississippi News

New leader brings seven years' experience from Oklahoma center

Cnl As Outcomes Manager: Improving Communication During The Er To Icu Handoff, Amy Ho

Master's Projects and Capstones

Emergency room (ER) to Intensive care unit (ICU) handoff reports are often ineffective because the lack of an standardized guideline. The aim of the Clinical Nurse Leader (CNL) improvement project was to improve the nurse satisfaction survey scores in the ER and ICU microsystems within a mid-sized community hospital in northern California. Participates included registered nurses, and ER and ICU managers. The failure mode and effect analysis (FMEA), Strength, weaknesses, opportunities, and threats (SWOT) analysis, and the Plan-Do-Study-Act (PDSA) cycle were used for this project. Literature reviews were conducted to identify effective theories, patterns, and tools for handoff reports. Nurse …

Creating A Culture Of Learning: Improving Patient Mobility In A Medical-Surgical Unit, Camille Cabalsa

Master's Projects and Capstones

Abstract

PROBLEM: Hospitalization, especially among older adults aged 65 or over, can result in decreased mobility and functional decline. This decreased mobility can lead to accelerated bone loss, falls, increased length of stay, and delirium. In this medical-surgical unit, a pattern reflecting lack of adequate patient mobility has persisted over one year.

CONTEXT: Northwest (NW), a 42-bed community hospital medical-surgical unit- part of an integrated regional health care delivery system, has not been maximizing the mobilization of their patients for the past year based on internal data.The improvement project described in this paper focused on creating a culture of continuous …

Isolated Gonococcal Extensor Tenosynovitis, Cory Lebowitz, Jonas Matzon

Department of Orthopaedic Surgery Faculty Papers

Neisseria gonorrhoeae is a mucosal infection that has the propensity to disseminate, causing symptoms that commonly include arthralgias, skin lesions, fevers, chills, dysuria, genital discharge, septic arthritis, and/or tenosynovitis. Typically, gonococcal tenosynovitis affects the flexor sheath and is associated with arthralgias, skin lesions, or both. To the best of our knowledge, there has not been a documented case of isolated gonococcal extensor tenosynovitis. We report the case of a 16-year-old boy with isolated left upper-extremity gonococcal extensor tenosynovitis who was successfully treated with surgical debridement and antibiotic therapy.

An Analysis Of Dynamic Price Discrimination In Airlines, Diego Escobari, Nicholas G. Rupp, Joseph Meskey

School of Economics and Finance Faculty Publications

Prices for the same flight change substantially depending on the time of purchase. This article uses a unique data set with round‐the‐clock posted fares to document significant within‐day price variation. Labeling time‐variation as discriminatory is difficult because the cost of an unsold airline seat changes with inventory, days before departure, and aggregate demand expectations. After controlling for these factors and aggregating hourly fares to have a framework with two consumer types, we are able to identify a component that is largely consistent with dynamic price discrimination. We find higher prices during office hours (when business travelers are likely to buy) …

Development Of A Step Counting Algorithm Using The Ambulatory Tibia Load Analysis System For Tibia Fracture Patients, Arad Lajevardi-Khosh, Ben Tresco, Ami Stuart, Sarina Sinclair, Matt Ackerman, Erik Kubiak, Tomasz Petelenz, Robert Hitchcock

School of Medicine Faculty Research

Introduction: Ambulation can be used to monitor the healing of lower extremity fractures. However, the ambulatory behavior of tibia fracture patients remains unknown due to an inability to continuously quantify ambulation outside of the clinic. The goal of this study was to design and validate an algorithm to assess ambulation in tibia fracture patients using the ambulatory tibial load analysis system during recovery, outside of the clinic. Methods Data were collected from a cyclic tester, 14 healthy volunteers performing a 2-min walk test on the treadmill, and 10 tibia fracture patients who wore the ambulatory tibial load analysis system during …

Action Collection Service Inc. V. Black Appellant's Brief Dckt. 46116

Not Reported

No abstract provided.

An Engineered Fit-For-Purpose Polymer Nanocomposite Seal Repair Material For Wellbores, Moneeb Genedy

Civil Engineering ETDs

Seal integrity of wellbores has become of significant interest due to repeated leakage and spill incidents occurring worldwide that jeopardize both human health and the environment in addition to causing significant economic burden. This is attributed to the fact that wellbores intersecting geographical formations contain potential leakage pathways. The cement-steel and cement-rock formation interfaces are recognized as two critical leakage pathways.

A seal repair material that has good bond strength with both steel and rock formations in addition to the ability to completely fill thin microcracks is needed to restore the seal integrity of wellbores. In this research, engineered polymer …

Mothers’ Voices: A Narrative Study Of The Experiences And Perspectives Of Mothers Raising School Age Children With Disabilities In One Of Zimbabwe’S Urban Areas, Emillia Masaka

Special Education ETDs

This narrative study examined (1) how women raising school age children with disabilities in one of Zimbabwe’s urban areas, articulated and conceptualized (a) their children’s disabilities and (b) their experiences as mothers of children with disabilities and (2) how their social status, marital status, age, ethnicity, and/or race intersected with their experiences of raising children with disabilities. A localized understanding of how mothers view their children’s disabilities was important because it influences results of any interventions their children might receive. Eight participants volunteered to have three interviews each, with me. Utilizing the social construction of disability, intersectionality, and thematic analysis …

A Method For Use Phase Definition As Integrated Into An Object-Oriented Approach To Life Cycle Assessment, Alissa Marie Santucci

Theses

As global environmental concerns increase, industries continue to respond prominently to meeting sustainable practice standards through technological innovations and new business models. However, current sustainability measurement tools, including Life Cycle Assessment (LCA), do not provide practitioners with sufficiently standardized methodology, which leads to uncertainty and limited comparability of results. This research develops a systematic Object-Oriented LCA method to define and quantify the consumed life of a product system during the use scenario under analysis. In this method, the Cumulative Damage Function (CDF) quantifies the consumed life of a product by using inputs of total efficiency or damage, scaling parameters and …