Digital Commons Network^™

Freeze Extrusion Fabrication Of 13-93 Bioactive Glass Scaffolds For Bone Repair, Nikhil D. Doiphode

Masters Theses

"We have investigated Freeze Extrusion Fabrication (FEF) of 13-93 bioactive glass to fabricate three dimensional scaffolds for bone tissue engineering. Bioactive glass paste was prepared for consistent extrusion through micro-nozzle and controlled porosity scaffolds were fabricated using additive manufacturing FEF. CAD models were prepared for different scaffold designs and computer controlled layer-by-layer deposition of pseudoplastic paste was carried out to in accordance. Liquid nitrogen assisted freezing of pastes was used for the consolidation of deposited layers. Post processing binder burnout and sintering schedules were designed for evaporation of organic binder and densification of glass. Sintering shrinkage was measured, and X-ray …

Impaired Vascular Reactivity Following Chronic Ischemia In The Arteries Of The Mouse Hindlimb, Thomas (Tom) Kesler

Biomedical Engineering

Collateral dependent hyperemia is reduced following chronic ischemia, but the contribution of individual vessel reactivity is unknown. Further, it is not known what aspect of the complex ischemic injury response impacts vascular reactivity. To determine the impact of ischemia on vascular reactivity, we measured functional vasodilation in the muscular branch artery following resection of the femoral artery proximal to the muscular branch. On day-14 after surgery the diameter of the muscular branch was measured using side-stream dark field (SDF) imaging intravital microscopy. At moderate intensity skeletal muscle contraction (1mA, 200µs, 8Hz, 90sec), functional vasodilation is reduced compared to the contralateral …

Morphological Assessment Of Basic Multicellular Unit Resorption Parameters In Dogs Shows Additional Mechanisms Of Bisphosphonate Effects On Bone, Matthew R. Allen, Antonia M. Erickson, Xiang Wang, David B. Burr, R. Bruce Martin, Scott J. Hazelwood

Biomedical Engineering

Bisphosphonates (BPs) slow bone loss by reducing initiation of new basic multicellular units (BMUs). Whether or not BPs simply prevent osteoclasts from initiating new BMUs that resorb bone or also reduce the amount of bone they resorb at the BMU level is not clear. The goal of this study was to determine the effects of BPs on three morphological parameters of individual BMUs, resorption depth (Rs.De), area (Rs.Ar), and width (Rs.Wi). After 1 year of treatment with vehicle (VEH), alendronate (ALN; 0.10, 0.20, or 1.00 mg/kg/day), or risedronate (RIS; 0.05, 0.10, or 0.50 mg/kg/day), resorption cavity morphology was assessed in …

Development Of A Framework For The Assessment Of The Role And Impact Of Technology On The Public Procurement Process: An Irish Health Sector Study, Paul Davis

Doctoral

This thesis sets out to examine how the role and impact of technology, in the context of the public procurement process, can be assessed by addressing it as a single bounded structural entity. The thesis specifically examines the procurement process in the Irish Health Sector. This thesis takes the view that context for the procurement process is critical and that adopting a structuration approach to the examination of the process allows for a greater understanding of the role of technology. The thesis is built around a thematic structure which examines the changing relationship between information technology systems and organisational structure. …

Computational Thinking Across The Curriculum: A Conceptual Framework, Amber Settle, Ljubomir Perkovic

Technical Reports

We describe a framework for implementing computational thinking in a broad variety of general education courses. The framework is designed to be used by faculty without formal training in information technology in order to understand and integrate computational thinking into their own general education courses. The framework includes examples of computational thinking in a variety of general education courses, as well as sample in-class activities, assignments, and other assessments for the courses. The examples in the different courses are related and differentiated using categories taken from Peter Denning’s Great Principles of Computing, so that similar types of computational thinking appearing …

A Simulation Study Of Factors That Affect Pressure Control During Kick Circulation In Managed Pressure Drilling Operations, Jose Eduardo Eduardo Chirinos

LSU Master's Theses

An university-industry consortium has been studying alternative well control procedures to be used for kicks taken during managed pressure drilling (MPD) operations using the constant bottom hole pressure (CBHP) method. The CBHP method of MPD allows more precise control of wellbore pressure than conventional drilling. MPD surface equipment allows more alternatives for controlling a kick and may support faster detection of kicks and losses which can reduce the severity of a well control event. Nevertheless, the elimination of well control incidents cannot be guaranteed, and the uncertainty in downhole drilling margins are not reduced by adopting MPD methods. The primary …

The Effects Of Lean On Employees' Affective Attitude In A Modular Homebuilding Manufacturer, Digvesh Khot

LSU Master's Theses

Many organizational problems are related to job dissatisfaction, job-related stress, and lack of commitment in workers. Employees’ Affective Attitude (EAA) involves these three factors: job satisfaction, job stress, and commitment. This research is aimed at measuring the impact of Lean concepts on EAA factors. While providing an overview of Lean production and construction, this study focuses on one fundamental Lean concept, Kaizen. This thesis describes a case study showcasing the application of Lean concepts through Kaizen events and its impact on EAA for a modular homebuilder company. Based on previous literature a conceptual model was developed describing the potential links …

Characterization Of Composite Piezoelectric Materials For Smart Joint Applications, Hari Prasad Konka

LSU Master's Theses

Piezoelectric materials have the ability to provide desired transformation from mechanical to electrical energy and vice versa. When a mechanical force is applied to the piezoelectric material an electrical voltage is generated and when an electrical voltage is applied to the piezoelectric material it gets strained or deformed. Owing to these characteristics piezoelectric materials can be used as a sensor, an actuator, as well as a power generation unit. The high brittleness property of the original piezoelectric material is one of the major constraints in using them in the engineering applications. In order to overcome this disadvantage the composite piezoelectric …

Organic Particulate Matter Formation At Varying Relative Humidity Using Surrogate Secondary And Primary Organic Compounds With Activity Corrections In The Condensed Phase Obtained Using A Method Based On The Wilson Equation, James F. Pankow, E. I. Chang

Civil and Environmental Engineering Faculty Publications and Presentations

Secondary organic aerosol (SOA) formation in the atmosphere is currently often modeled using a multiple lumped "two-product" (N · 2p) approach. The N · 2p approach neglects: 1) variation of activity coefficient (i) values and mean molecular weight MW in the particulate matter (PM) phase; 2) water uptake into the PM; and 3) the possibility of phase separation in the PM. This study considers these effects by adopting an (N ·2p)pMW, approach (is a phase index). Specific chemical structures are assigned to 25 lumped SOA compounds and to 15 representative primary organic aerosol (POA) compounds to allow calculation of i …

Experimental Study On Single Cement Fracture Exposed To Co2 Saturated Brine Under Dynamic Conditions, Tevfik Yalcinkaya

LSU Master's Theses

Carbon capture and storage is one of the technologies that could help reduce CO2 concentration in the atmosphere while contributing to cutback of Greenhouse Gas emissions. Depleted oil and gas fields are favorable targets for CO2 storage because existing wells can be readily used as injection wells. However, a number of abandoned wells also serve as gateway to the reservoir which should be considered in the context of effective Carbon capture and storage. Wellbore cement is a very essential element in wellbore systems that serve as a barrier between different zones in the subsurface. The fractures inside wellbore cement sheath, …

Degradation Behavior Of Shape Memory Polymer Due To Water And Diesel Fuel, Mohammad Nazmul Hasan Nahid

LSU Master's Theses

Shape memory polymers (SMP) are smart materials, which have the ability to memorize the original or permanent shape. Owing to this characteristic SMP can be used as a sensor, a transplant, as well as structural materials in wide range of applications. Despite its importance, its degradation behavior is still not completely known; and only a limited amount of work has been reported in the literature. In this thesis, the experiments have been carried out to evaluate the degradation behavior of Veriflex- SMP (industry supplied SMP samples) upon exposure to two different types of liquids; water and diesel fuel separately. It …

Effect Of Management Awareness Of Safety Climate Concept On Organizational Safety Climate, Christopher Michael Holzner

LSU Master's Theses

Safety research and practice have shifted focus away from accident rates and accident causal information to a more proactive approach that may predict organizational safety trends. This proactive approach involves the concept of an organizational safety culture and the use of surveys to measure organizational safety climate or „snapshot‟ of the organizational safety culture. Surveys were administered to line workers, supervisors, and managers at a modular home manufacturing company before and after safety climate information was presented to supervisors and managers in an attempt to measure the effect of the supervisors‟ and managers‟ increased awareness of the factors that define …

Empirically Evaluating And Developing Alarm Rate Standards For Liquid Pipeline Control Room Operators, Glen David Uhack Ii

LSU Master's Theses

The liquid and gas pipeline community has recently been faced with the challenge of new governmental regulations set forth by congress which are being implemented by PHMSA (an arm of the DOT). These new governmental regulations need to understand the role of the human in the loop as part of alarm management systems. To investigate alarm rate standards a repeated measures design was developed that included a series of ten (10) simulated liquid pipeline operator scenarios utilizing high fidelity liquid pipeline simulation software (Stoner Pipeline Simulator). A total of 39 participants volunteered for this study. Participants completed two subsets of …

Quantification Of Energy Intake Using Food Image Analysis, Sertan Kaya

LSU Master's Theses

Obtaining real-time and accurate estimates of energy intake while people reside in their natural environment is technically and methodologically challenging. The goal of this project is to estimate energy intake accurately in real-time and free-living conditions. In this study, we propose a computer vision based system to estimate energy intake based on food pictures taken and emailed by subjects participating in the experiment. The system introduces a reference card inclusion procedure, which is used for geometric and photometric corrections. Image classification and segmentation methods are also incorporated into the system to have fully-automated decision making.

Antisense Silver Nanoparticles For Photo-Activated Gene Silencing, Paige Kathleen Brown

LSU Master's Theses

The unique properties of noble metal nanoparticles, which include tunable electronic and photonic characteristics, contribute to their potential as novel delivery vectors with enhanced drug stability, cell uptake, and photo-activated functionalities. Silver, as one of best surface-enhancing substrates available for bulk nanostructure synthesis, is a prime choice for investigations of metal nanohybrids as antisense therapy vehicles with special surface plasmon resonance (SPR) enabled functional attributes. The singular photonic properties of silver nanoparticles (SNPs) may contribute to ease of delivery confirmation and in situ photo-activation of protected cargo packed on particle surfaces. Here we show the synthesis and characterization of 40-80nm …

Concurrent Masters Degrees Across The Atlantic: Innovations, Issues And Insights, Michael Dyrenfurth, Mike Murphy, Gary Bertoline, Robert Herrick, Kathryne Newton, Gareth O'Donnell, Donal Mchale, Nuria Castell, Miquel Barcelo, Didac Balas, Maria Ribera Sancho, Jordi Garcia

Conference papers

Atransatlantic degree consortium to implement a four-semester dual masters degree initiative across a three-institution consortium consisting of Purdue University (USA), the Technological University Dublin (DIT), and the Universitat Politècnica de Catalunya (Spain) is presented in this paper.

Characterization Of Legacy Organic Carbon In A Culturally Eutrophic Lake : The Role Of The Historic Carbon Deposition In The Time Course And Extent Of Lake Recovery , Phillip A. Depetro

Dissertations, Master's Theses and Master's Reports - Open

The time course of lake recovery after a reduction in external loading of nutrients is often controlled by conditions in the sediment. Remediation of eutrophication is hindered by the presence of legacy organic carbon deposits, that exert a demand on the terminal electron acceptors of the lake and contribute to problems such as internal nutrient recycling, absence of sediment macrofauna, and flux of toxic metal species into the water column. Being able to quantify the timing of a lake’s response requires determination of the magnitude and lability, i.e., the susceptibility to biodegradation, of the organic carbon within the legacy deposit. …

Characterizing The Effects Of Turbulence On Sediment Oxygen And Sediment Nitrate Demand Using Flow-Through Reactors, Brandon J. Ellefson

Dissertations, Master's Theses and Master's Reports - Open

Onondaga Lake has received the municipal effluent and industrial waste from the city of Syracuse for more than a century. Historically, 75 metric tons of mercury were discharged to the lake by chlor-alkali facilities. These legacy deposits of mercury now exist primarily in the lake sediments. Under anoxic conditions, methylmercury is produced in the sediments and can be released to the overlying water. Natural sedimentation processes are continuously burying the mercury deeper into the sediments. Eventually, the mercury will be buried to a depth where it no longer has an impact on the overlying water. In the interim, electron acceptor …

Energy Harvesting From Body Motion Using Rotational Micro-Generation, Edwar. Romero-Ramirez

Dissertations, Master's Theses and Master's Reports - Open

Autonomous system applications are typically limited by the power supply operational lifetime when battery replacement is difficult or costly. A trade-off between battery size and battery life is usually calculated to determine the device capability and lifespan. As a result, energy harvesting research has gained importance as society searches for alternative energy sources for power generation. For instance, energy harvesting has been a proven alternative for powering solar-based calculators and self-winding wristwatches. Thus, the use of energy harvesting technology can make it possible to assist or replace batteries for portable, wearable, or surgically-implantable autonomous systems. Applications such as cardiac pacemakers …

Posture Systematically Alters Ear-Canal Reflectance And Dpoae Properties, Susan E. Voss, Modupe F. Adegoke, Nicholas J. Horton, Kevin N. Sheth, Jonathan Rosand, Christopher A. Shera

Engineering: Faculty Publications

Several studies have demonstrated that the auditory system is sensitive to changes in posture, presumably through changes in intracranial pressure (ICP) that in turn alter the intracochlear pressure, which affects the stiffness of the middle-ear system. This observation has led to efforts to develop an ear-canal based noninvasive diagnostic measure for monitoring ICP, which is currently monitored invasively via access through the skull or spine. Here, we demonstrate the effects of postural changes, and presumably ICP changes, on distortion product otoacoustic emissions (DPOAE) magnitude, DPOAE angle, and power reflectance. Measurements were made on 12 normal-hearing subjects in two postural positions: …

Understanding User-Generated Content On Social Media, Bala Meenakshi Nagarajan

Browse all Theses and Dissertations

Over the last few years, there has been a growing public and enterprise fascination with 'social media' and its role in modern society. At the heart of this fascination is the ability for users to participate, collaborate, consume, create and share content via a variety of platforms such as blogs, micro-blogs, email, instant messaging services, social network services, collaborative wikis, social bookmarking sites, and multimedia sharing sites.

This dissertation is devoted to understanding informal user-generated textual content on social media platforms and using the results of the analysis to build Social Intelligence Applications.

The body of research presented in this …

Automated Tank Surface Finishing System, Purdue Ect Team

ECT Fact Sheets Archive

The current finishing techniques are costly and laborious, and they expose workers to significant health and safety risks. The automated tank surface finishing system uses a computer-controlled motion module to refinish the vertical exterior walls of a tank. The module is configurable for both blasting and painting and utilizes conventional surface finishing equipment for these processes. An overspray hood is included to reduce contamination of the surrounding environment during painting. The module attaches to a tank’s wind girts with steel cables, and its position and velocity are controlled by servo-driven hoists.

Develop Sonic Infrared Imaging Nde For Local Damage Assessment In Civil Structures, Qi He

Wayne State University Dissertations

Nondestructive Evaluation (NDE) is an interdisciplinary field of study, which is concerned with the development of analysis techniques and measurement technologies for the quantitative characterization of materials, tissues and structures. Ultrasonic IR Imaging is a novel NDE technique, which combines a short ultrasonic pulse excitation and infrared imaging to detect defects in materials and structures. In this technique, a sound pulse with a frequency in the range of 20-40kHz is infused on a target material for a short duration (usually less than one second). The sonic/ultrasonic sound waves travel into the material and cause rubbing and clapping between the surfaces …

Unified Role Assignment Framework For Wireless Sensor Networks, Manish Mahendra Kumar Kochhal

Wayne State University Dissertations

Wireless sensor networks are made possible by the continuing improvements in embedded sensor, VLSI, and wireless radio technologies. Currently, one of the important challenges in sensor networks is the design of a systematic network management framework that allows localized and collaborative resource control uniformly across all application services such as sensing, monitoring, tracking, data aggregation, and routing.

The research in wireless sensor networks is currently oriented toward a cross-layer network abstraction that supports appropriate fine or course grained resource controls for energy efficiency. In that regard, we have designed a unified role-based service paradigm for wireless sensor networks. We pursue …

The Fourier Spectrum Element Method For Vibration And Power Flow Analysis Of Complex Dynamic Systems, Hongan Xu

Wayne State University Dissertations

A general numerical method, the so-called Fourier-Space Element Method (FSEM), is proposed for the vibration and power flow analyses of complex built-up structures. In a FSEM model, a complex structure is considered as a number of interconnected basic structural elements such as beams and plates. The essence of this method is to invariably express each of displacement functions as an improved Fourier series which consists of a standard Fourier cosine series plus several supplementary series/functions used to ensure and improve the uniform convergence of the series representation. Thus, the series expansions of the displacement functions and their relevant derivatives are …

Modeling Of Transient Response Of An Elastic Beam With Flexible Supports And Variable-Location Impact, Weiping Xu

Electronic Theses and Dissertations

This research is prerequisite to determining structural health and estimating wear-limited life of contact/impact machinery components. Prevention, or at least early notification, of impact-induced wear is essential for preventing economic loss and enhancing personnel safety. Thus, an efficient model which is discrete in time and continuous in space was undertaken; an euler-bernoulli beam with adjustable boundary conditions and variable impact is numerically studied under a pulse loading. Structural stiffness, material modulus, contact stiffness, contact location, damping ratio, pulse duration, clearance and boundary conditions are investigated. A reference system is used as the basis for parameter studies and solution convergence is …

Composition-Structure-Property Relationships In Multicomponent Bioactive Glasses, Sharon Murphy

Theses

Silicate glasses function effectively as bone grafts by stimulating bone regeneration through gene activation. However these materials offer little therapeutic potential for the regeneration of healthy bone in those suffering from metabolic bone diseases such as osteoporosis. Examining the composition-structure-property relationships arising from the incorporation of therapeutic ions such as strontium (Sr) and zinc (Zn) into such glasses in order to allow for healthy bone regeneration and antibacterial efficacy, as well as sodium (Na) to allow for controlled ion release was the objective of this work. Eight calcium-strontium-sodium-zinc-silicate glass compositions were produced, based on incremental additions of Sr and Na. …

Solid Oxide Fuel Cell Electrode Characterization And Improvement For Fuel Flexibility And Supplemental Power Production, Isaiah D. Kellogg

Doctoral Dissertations

"Solid oxide fuel cells (SOFC) were fabricated and the electrodes tested for their individual catalytic effectiveness in various fuels by exposing each electrode to mixed gas while the opposite electrode was exposed to its respective pure gas. Mixed hydrogen and oxygen gas was successfully utilized as fuel in a single chamber SOFC (SC-SOFC). The conditions at which the porous nickel-yttria-stabilized zirconia (Ni-YSZ) cermet anode performed well did not significantly overlap the conditions at which the La₀.₈Sr₀.₂Fe₀.₈Co₀.₂ oxide (LSCF) cathode performed well, but there was significant catalytic activity at both electrodes which increased the open circuit voltage (OCV) beyond that predicted …

Crack Detectability And Durability Of Coaxial Cable Sensors In Reinforced Concrete Bridge Applications, Genda Chen, Ryan D. Mcdaniel, Michael A. Brower, David Pommerenke

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The working mechanism and the measurement principle of topology-based crack sensors made of coaxial cables are briefly reviewed. The sensitivity, spatial resolution, and ruggedness of two coaxial cable sensors, respectively made of rubber and Teflon dielectric materials, were compared and validated with laboratory testing of a 4/5-scale, T-shaped, reinforced concrete beam-column specimen. Two Teflon sensors were installed on one of the solid decks of a three-span continuous highway bridge to investigate their durability and measurement repeatability. Laboratory tests indicated that both types of sensors have high sensitivity, but the Teflon sensor has a higher spatial resolution and a negligible spillover …

Characterization Of The Corrosion Protection Mechanism Of Cerium-Based Conversion Coatings On High Strength Aluminum Alloys, William R. Pinc

Doctoral Dissertations

"The aim of the work presented in this dissertation is to investigate the corrosion protection mechanism of cerium-based conversion coatings ( CeCCs) used in the corrosion protection of high strength aluminum alloys. The corrosion resistance of CeCCs involves two general mechanisms; barrier and active. The barrier protection mechanism was influenced by processing parameters, specifically surface preparation, post-treatment, and the use of gelatin. Post-treatment and the addition of gelatin to the coating solution resulted in fewer cracks and transformation of the coating to CeP0₄, which increased the corrosion resistance by improving the barrier aspect of CeCCs. CeCCs were found to best …