Other Materials Science and Engineering Commons^™

Crystalline Analysis Of Geomicrobially-Induced Calcium Carbonate Precipitation In Sands Using A Surface Percolation Treatment Technique, Justin Edward Mulloney

UNF Graduate Theses and Dissertations

Ottawa 50/70 sand specimens and natural beach sand samples were treated using bio-augmented geomicrobies via a surface percolation technique. Testing was conducted on these specimens to determine how resultant calcium carbonate precipitation changed as a function of temperature, depth from the surface, and in the presence of magnesium. Specifically, x-ray Diffraction (XRD), a Scanning Electron Microscope (SEM), and Energy Dispersive X-ray Spectroscopy (EDS) were used to determine and quantify the presence of calcium carbonate and its associated phase. Results showed a direct relationship between temperature and precipitated calcium carbonate. In addition, as an unintended consequence associated with the treatment, ammonium …

Electrochemical Chloride Removal, Marcus Yudt

Williams Honors College, Honors Research Projects

Electrochemical chloride removal (ECR) was tested to see its effectiveness in preventing corrosion on rebar samples within 3.5 wt% sodium chloride concrete. In order to do this, three scenarios were evaluated using electrochemical techniques such as cyclic potentiodynamic polarization and electrochemical impedance spectrsoscopy as well as visual inspections. The three scenarios that were evaluated were one with no chlorides present within the concrete, one that was a worst-case scenario where extreme pitting and corrosion were initiated, and one that had chlorides present and received the ECR treatment. Cyclic polarization curves showed that the ECR and reference without chlorides had similar …

Analysis And Comparison Of Nir Pigments For "Cool" Coating Applications, Karey Steinmetz

Williams Honors College, Honors Research Projects

The goal of this research is to compare our own formulation of near infrared radiation (NIR) pigment coating to commercialized ones. These near infrared coatings are designed to be used on roofs of buildings to keep the buildings from absorbing the heat from the sun’s radiation. This would keep the building cooler and use less energy and money to cool the building. In this study, Styrofoam was used to build a lab-scale house and were put under heat lamps that mimicked the sun. Temperatures were taken at three different locations to determine the effectiveness of the pigmented coatings. Color and …

Electrochemical Impedance Spectroscopy Analysis Of Corrosion Of Reinforcing Steel In Fly Ash Mortar By Means Of Transmission Line Modeling, Padraig Stack

Williams Honors College, Honors Research Projects

Electrochemical impedance spectroscopy (EIS) is an important non-destructive tool that allows for a deeper understanding of the electrochemical processes and mechanisms occurring in an electrochemical cell. Equivalent electrical circuits (EECs) are used to model the impedance data into electrical components, such as resistors and capacitors, on a circuit. Current potentiostat offers software packages that can analyze the frequency response, but the software only supports “simple” EEC that can be written as fixed electrical components in some combination of series and parallel. Park and Macdonald propose a transmission line model (TLM) that does not use lumped-element models, instead, the values of …

Magnetic Field Penetration Technique To Study Field Shielding Of Multilayered Superconductors, I.H. Senevianthe, Alex Gurevich, Jean R. Delayen, A-M Valente-Feliciano, Kenji Saito (Ed.), Ting Xu (Ed.), Yana Lesage (Ed.), Volker R.W. Schaa (Ed.)

Physics Faculty Publications

The SIS structure which consists of alternative thin layers of superconductors and insulators on a bulk niobium has been proposed to shield niobium cavity surface from high magnetic field and hence increase the accelerating gradient. The study of the behavior of multilayer superconductors in an external magnetic field is essential to optimize their SRF performance. In this work we report the development of a simple and efficient technique to measure penetration of magnetic field into bulk, thin film and multilayer superconductors. Experimental setup contains a small superconducting solenoid which can produce a parallel surface magnetic field up to 0.5 T …

Characterization Of Material For Composite Automotive Components, Thomas J. Chang

Electronic Thesis and Dissertation Repository

A composite had been widely used for the lightweighting purpose amid increasing environmental concerns. Among composite manufacturing processes, compression molding is widely used for automotive parts. During compression molding, the mold geometry and molding process conditions significantly influence the fiber configuration and the mechanical performance.

Hence, this thesis aims to characterize the microstructural and mechanical properties of the complex shaped composite automotive components: outer seatback and inner seatback. Both parts were compression molded using commercial glass mat thermoplastic sheet with long glass fibers (30mm-50mm) embedded in the polyamide resin. The microstructural characterization results showed that the microstructural properties are influenced …

Simulation And Fabrication Of All Oxide-Based Ito/Tio2/Cuo/Au Heterostructure For Solar Cell Applications, Sajal Islam

MSU Graduate Theses

Oxide heterostructures have drawn great attention lately, due to their environment-friendly properties and potential applications in optoelectronic devices. In this work, a simulation study of a heterojunction solar cell was performed with SCAPS (a solar cell simulator) using TiO2 as an n-type and CuO as a p-type layer. The thickness and the dopant-dependent simulations have shown that the solar cell operates at a maximum efficiency of 19.2% when the thickness of the TiO2/CuO layers is chosen 1.4µm/1.2µm compared to the 11.5% efficiency when FTO is replaced with ITO. An indium-doped tin oxide (ITO) vs fluorine-doped tin oxide (FTO) comparison study …

Growth, Characterization, And Mechanical Testing Of Diamond-Like Carbon Films, Tailei Qi

LSU Master's Theses

The high residual stresses within diamond-like carbon (DLC) films limit its thickness and make the film tend to delaminate from the substrate and be defective on the surface. To address this problem, a new plasma enhanced chemical vapor deposition system (PECVD) was set up to investigate the effects of different film growth parameters on the DLC films, such as chromium doping, gas fluxes, depositing pressures, bias voltages, and depositing times. After the film growth parameters were optimized, this condition was transferred from silicon wafer to SS316 steel plate to deposition of DLC films with some adjustments. Scanning electron microscopy (SEM) …

Biodegradable Nanocomposite Multifunctional Packaging Film For Fruits, Kalpani Y. Perera, Shubham Sharma, Dileswar Pradhan, Amit Jaiswal, Swarna Jaiswal

Articles

Biopolymers have been used in food packaging in recent years due to high pollution rates and decreased biodegradation of synthetic polymers. Chitosan (CH) and Sodium alginate (SA) are both biodegradable biopolymers with excellent film forming capability. TiO2 nanoparticles have high mechanical strength, degradation ability and antimicrobial properties, which are beneficial in food packaging. The aim of the current work is to develop the biodegradable multifunctional nanocomposite film for fruit (i.e., Pear) packaging applications. Bionanocomposite film was prepared by solvent casting method using CH-SA and various concentrations of TiO2. The multifunctional properties such as UV barrier, thermal, water retention, mechanical, chemical, …

Atomistic Simulation Of Desalination, Ian David Durr

Symposium of Student Scholars

Atomistic Simulation of Desalination

Ian Durr, Matheus Prates, and Jungkyu Park

Kennesaw State University

In this research, we investigate the desalination capacity of three-dimensional (3D) carbon nanostructures using molecular dynamics simulations. 3D carbon nanostructures proposed here will filter seawater efficiently because of their multiple layers with holes of tunable sizes. The structure is designed to be flexible, allowing mechanical deformation during daily use. The 3D carbon nanostructure will still possess high thermal conductivity, enabling easy recycle through a simple heating process. Here, we employ LAMMPS, Large-scale Atomic/MolecularMassively Parallel Simulator distributed by Sandia National Laboratories to measure salt ion flux through …

Engineering The Surface Of Fe3o4 Nanoparticles For Catalytic And Magnetic Applications, Natalia Da Silva Moura

LSU Doctoral Dissertations

With the rapid depletion of the U.S. energy resources coupled with population growth, heat management technologies must be improved to sustain our quality of life. Precisely, in catalysis, it is estimated that only ~50% of the energy supplied to the reactor is used for product conversion due to dissipation losses. Among the emerging technologies with a promising reduction in heat losses is induction heating, offering targeted heat delivery with magnetic nanoparticles. Under alternating magnetic fields (AMF), these nanoparticles can absorb the energy from Radio-Frequency (RF) fields and dissipate it as heat on the nanoparticle surface. This in situ heat generation …

Direct Activation Of Light Alkanes To Value-Added Chemicals Using Supported Metal Oxide Catalysts, Md Ashraful Abedin

LSU Doctoral Dissertations

One of the most challenging aspects of modern-day catalysis is the conversion of methane. Direct conversion of methane via dehydroaromatization (MDHA) is a well-known process which can produce valuable hydrocarbons. Mo oxide supported on ZSM-5/MCM-22 has been studied extensively in recent years for MDHA. Mo carbides are responsible for activating methane by forming CHx species. These are dimerized into C2Hy and oligomerized on ZSM-5/MCM-22 Brønsted acid sites to form aromatics. Sulfated zirconia (SZ) supported Mo catalyst contains the acid sites necessary to produce benzene in MDHA. Here, sulfated hafnia (SH), a homologous oxide like SZ, has been proposed to provide …

Understanding Colloidal And Surface Phenomena To Manufacture Energy-Dense Lithium-Ion And Solid-State Battery Cathodes, William B. Hawley

Doctoral Dissertations

Lithium-ion batteries (LIB) are a technology that have been commercialized since 1991 for portable electronics. Research and development have dramatically reduced the cost of LIBs over the past ten years such that it is becoming more feasible that electric vehicles utilizing LIBs can compete with vehicles using the internal combustion engine. To continue to reduce the cost of LIBs, novel cathode processing strategies must be pursued and the impact of these strategies on the cathode’s microstructure and performance must be well-understood. Moving beyond LIBs, solid-state lithium metal batteries (SSLMBs) are a safer, more energy-dense alternative due to non-flammable, thin solid …

Mixed Metal Oxide Nanowires Via Solid State Alloying., Veerendra Atla

Electronic Theses and Dissertations

Mixed metal oxide materials with composition control find applications in energy conversion and storage processes such as heterogenous catalysis, photoelectrochemical catalysis, electrocatalysis, thermal catalysis, and lithium-ion batteries. Mixed metal oxides and/or complex oxides with composition control and in one-dimensional form as nanowires could be interesting to various catalysis applications due to control on single crystal surfaces, active sites, acidity versus basicity site density, and oxygen vacancies. The major challenge is to synthesize mixed metal oxide nanowires beyond binary oxides with composition control. In this dissertation, solid state alloying of binary oxide nanowires with solid and liquid precursors is studied to …

Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed

LSU Master's Theses

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali …

Development Of A Wireless Telemetry Load And Displacement Sensor For Orthopaedic Applications, William Anderson

Electronic Thesis and Dissertation Repository

Due to sensor size and supporting circuitry, in vivo load and deformation measurements are currently restricted to applications within larger orthopaedic implants. The objective of this thesis is to repurpose a commercially available low-power, miniature, wireless, telemetric, tire-pressure sensor (FXTH87) to measure load and deformation for future use in biomechanical applications. The capacitive transducer membrane of the FXTH87 was modified, and a relationship was reported between applied compressive deformation and sensor signal value. The sensor package was embedded within a deformable enclosure to illustrate potential applications of the sensor for monitoring load. Finite element analysis was an effective tool to …

Optimization Of 3d Printed Mold Performance For Injection Molding Via Hollow Infill Patterns, Alan Fong

University Honors Theses

The applicability of hollow infill patterns has been explored for its applications in making 3D printed polymer-based injection molds in the additive manufacturing industry. Hollow infill patterns offer a significant reduction in material costs as well as the opportunity for reducing the cooling times via pumping a coolant fluid through the hollow cavity in a similar fashion to traditional conformal cooling channels. A 3D Jacks Support Hollow mold model was determined to be the best performing design. FEA analysis was conducted to determine the maximum reduction in internal volume (percentage of material saved) that could be achieved without exceeding the …

Direct Printing/Coating/Plating Of Key Components For Electronic Devices, Xiyu Hu

Doctoral Dissertations

Miniaturization has been a technological trend for several decades for electronic devices. From the practical point of view, the successful miniaturization of fully integrated systems mainly depends on their components. This dissertation examines the inkjet printing of copper oxide inks on flexible substrates for applications in microfluidic valving systems. We expand the knowledge of low-cost and high-performance electrowetting valves and fabricate the microfluidic device for fluidic control, which is necessary to enable the next-generation microfluidic devices. In addition, we also study the electromagnetic interference (EMI) shielding material, which is a crucial part of electronic devices. The basic theory of EMI …

Harnessing The Mechanics Of Thin-Walled Metallic Structures: From Plate-Lattice Materials To Cold-Formed Steel Shear Walls, Fani Derveni

Doctoral Dissertations

Thin-walled structures have received a lot of interest during the last years due to their light weight, cost efficiency, and ease in fabrication and transportation, along with their high strength and stiffness. This dissertation focuses on the mechanical performance of thin-walled metallic structures from cold-formed steel shear walls and connections (PART I) to plate-lattice architected materials (PART II) via computational, experimental, and probabilistic methods.

Cold-formed steel (CFS) shear walls subjected to seismic loads is the focus of PART I of this dissertation. An innovative three-dimensional shell finite element model of oriented strand board (OSB) sheathed CFS shear walls is introduced …

Investigation Of Bipolar Electrochemically Exfoliated Graphene For Supercapacitor Applications, Iman Khakpour

FIU Electronic Theses and Dissertations

Developing a reliable, simple, cost-efficient and eco-friendly method for scale-up production of high-quality graphene-based materials is essential for the broad applications of graphene. Up to now, various manufacturing methods have been employed for synthesizing high quality graphene, however aggregation and restacking has been a major issue and the majority of commercially available graphene products are actually graphite microplates. In this study, bipolar electrochemistry techniques have been used to exfoliate and deposit graphene nanosheets in a single-step process to enable high performance device application.

In the first part of this study, bipolar electrochemistry concept is utilized to design a single-step and …