Materials Science and Engineering Commons^™

Design, Fabrication, And Characterization Of Novel Optoelectronic Devices For Near-Infrared Detection, Ahmad Nusir

Graduate Theses and Dissertations

Investigating semiconductor materials and devices at the nanoscale has become crucial in order to maintain the exponential development in today’s technology. There is a critical need for making devices lower in power consumption and smaller in size. Nanoscale semiconductor materials provide a powerful platform for optoelectronic device engineers. They own interesting properties which include enhanced photoconductivity and size-tunable interband transitions.

In this research, different types of nanostructures were investigated for optoelectronic devices: nanocrystals, nanowires, and thin-films. First, lead selenide nanocrystals with narrow bandgap were synthesized, size-tailored, and functionalized with molecular ligands for the application of uncooled near-infrared photodetectors. The devices …

Design, Fabrication, And Characterization Of All-Inorganic Quantum Dot Light Emitting Diodes, Ramesh Vasan

Graduate Theses and Dissertations

Quantum dot light emitting diodes are investigated as a replacement to the existing organic light emitting diodes that are commonly used for thin film lighting and display applications. In this, all-inorganic quantum dot light emitting diodes with inorganic quantum dot emissive layer and inorganic charge transport layers are designed, fabricated, and characterized. Inorganic materials are more environmentally stable and can handle higher current densities than organic materials. The device consists of CdSe/ZnS alloyed core/shell quantum dots as the emissive layer and metal oxide charge transport layer. The charge transport in these devices is found to occur through resonant energy transfer …

Phase Transitions In Monochalcogenide Monolayers, Mehrshad Mehboudi

Graduate Theses and Dissertations

Since discovery of graphene in 2004 as a truly one-atom-thick material with extraordinary mechanical and electronic properties, researchers successfully predicted and synthesized many other two-dimensional materials such as transition metal dichalcogenides (TMDCs) and monochalcogenide monolayers (MMs). Graphene has a non-degenerate structural ground state that is key to its stability at room temperature. However, group IV monochalcogenides such as monolayers of SnSe, and GeSe have a fourfold degenerate ground state. This degeneracy in ground state can lead to structural instability, disorder, and phase transition in finite temperature. The energy that is required to overcome from one degenerate ground state to another …

Peridynamic Modeling Of Dynamic Fracture In Bio-Inspired Structures For High Velocity Impacts, Sneha Akula

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Bio-inspired damage resistant models have distinct patterns like brick-mortar, Voronoi, helicoidal etc., which show exceptional damage mitigation against high-velocity impacts. These unique patterns increase damage resistance (in some cases up to 3000 times more than the constituent materials) by effectively dispersing the stress waves produced by the impact. Ability to mimic these structures on a larger scale can be ground-breaking and could be used in numerous applications. Advancements in 3D printing have now made possible fabrication of these patterns with ease and at a low cost. Research on dynamic fracture in bio-inspired structures is very limited but it is …

Investigation Of Nanomaterial Based Photovoltaic Panel Packaging Materials, Xingeng Yang

Graduate Theses and Dissertations

In this research, nanomaterial-based packaging materials for photovoltaic (PV) panels are investigated. A hydrophobic/anti-reflective surface coating which not only repels water from the top glass of a PV panel but at the same time reduces its light reflectance is investigated. COMSOL simulation results indicate that taller ellipsoid rod (aspect ratio = 5) reflects less light than shorter rod (aspect ratio = 0.5) in the desired spectrum for solar energy harvest from 400nm-700nm. The addition of a polymer layer on these ellipsoid rods broadens the light incident angle from 23° to 34°, from which light can be efficiently absorbed. Based on …

Fabrication And Characterization Of Graphene Based 2d Materials For Supercapacitors, Anishkumar Manoharan

Graduate Theses and Dissertations

Supercapacitors have attracted a lot attention due to their efficient energy storage. In comparison to batteries, supercapacitors have high capacitance, energy, and power densities per unit mass than conventional capacitors. Carbon based materials are most promising in supercapacitor application due to their outstanding physical and electrochemical behavior. In this work, a facile method to synthesize a nanocomposite electrode consisting of annealed carbon from carbon ink and MoS2 was demonstrated. Effects of various aqueous and solid electrolytes were studied. It was found that the nanocomposite electrode with 10% MoS2 and 1M Na2SO4 as the aqueous electrolyte tested using the three electrode …

Redshirt In Engineering: A Model For Improving Equity And Inclusion, Donna C. Llewellyn, Ann Delaney, Janet Callahan

Materials Science and Engineering Faculty Publications and Presentations

The NSF-funded Redshirt in Engineering Consortium was formed in 2016 with the goal of enhancing the ability of academically talented but underprepared students coming from low-income backgrounds to successfully graduate with engineering degrees. The Consortium takes its name from the practice of redshirting in college athletics, with the idea of providing an extra year and support to help promising engineering students complete a bachelor’s degree. The Consortium builds on the success of three existing “academic redshirt” programs and expands the model to three new schools. The Existing Redshirt Institutions (ERIs) help mentor and train the new Student Success Partners (SSP), …

Preparations And Corrosion Protection Investigations Of Diethylene Triamine Penta(Methylene Phosphonic Acid)-Zn2+ Conversion Coatings On Cold Rolled Steel Substrates, Wei He, Ru Yan, Ying-Qi Wang, Xiang Gao, Hou-Yi Ma

Journal of Electrochemistry

Novel diethylene triamine penta(methylene phosphonic acid) (DTPMPA)-zinc ion (Zn²⁺) conversion coatings with uniform blue color and excellent corrosion protection were directly formed on the cold rolled steel (CRS) substrates by immersing a CRS plate into the film-forming solutions containing the appropriate concentrations of DTPMPA and Zn²⁺ ion at the proper pH. In this paper, surface morphologies and elemental compositions of DTPMPA-Zn²⁺ conversion coatings were characterized by SEM and EDS, respectivey. The surface functional groups, chemical constituents and binding modes to the substrates were investigated by means of FTIR and XPS methods. The influences of DTPMPA concentrations …

Electrochemical Performance Of Moo2-C Composite Coatings, Quan-Yi Li, Qi Yang, Yan-Hong Zhao

Journal of Electrochemistry

The molybdenum dioxide-carbon(MoO₂-C)composite coatings on the surface of Cu foils were prepared by simple knife coating route and followed by sintering in vacuum. The morphology, composition, structure and electrochemical performance of the MoO₂-C composite coatings were investigated. The results demonstrated that the MoO₂-C composite coatings consist of MoO₂ nano-particles with monoclinic crystal structure and amorphous carbon. Some MoO₂ nano-particles with a size range of 5-30nm were loaded on the surface of carbon matrices; while some MoO₂ nano-particles with a size of ~5nm were encapsulated inside. The composite coatings showed porous structure …

Electrochemical Oxidation Of P-Chlorophenol On Porous Ti/Bdd Electrode Cooperated With Cathode Dechlorination, Rong-Ling Chen, Wei-Min Huang, Ya-Peng He, Jun Shi, Hai-Bo Lin

Journal of Electrochemistry

The electrochemical oxidation of p-chlorophenol on porous Ti/BDD electrode cooperated with synergistic effect of cathode dechlorination was studied. Electrochemical degradation tests of p-chlorophenol were conducted in single and double compartment electrolytic cells separately, and the results showed that the mineralization happened mainly in the anode region. The product of chloride ions produced from the cathodic reduction of 4-chlorophenol in the single cell migrated to the anode region and further generated active chlorine toward electro-catalytic oxidation. At the same time, the chloride ion produced from the cathode of the double cell was difficult to be migrated to the anode region, which …

Preparation Of Ni(Dpim)2Cl2 Complex For The Electrocatalytic Reduction Of Co2, Li-Pu Zhang, Dong-Fang Niu, Xin-Sheng Zhang

Journal of Electrochemistry

A new Ni(dpim)₂Cl₂complex using 2-(diphenylphosphino)-1-methylimidazole (dpim) as ligand was prepared and served as a catalyst for the electrochemical reduction of CO₂. The electrochemical redox behavior of Ni(dpim)₂Cl₂ in CH₃CN/TPABF₄ solution under nitrogen atmosphere showed the two-electron irreversible reduction at -0.7 V and one-electron quasi-reversible reduction at -1.3 V. After bubbling CO₂ into the electrolyte, the reduction peak appeared at -1.3 V became irreversible and the peak current increased from 0.48 mA·cm^-2 to 0.55 mA·cm^-2. Moreover, the peak current at -1.3 V could further increase …

Preparation And Properties Of Manganese Oxide And Polyaniline-Carbon Composite Electrode, Tian-Tian Zhou, Bing Wu, Chao Deng, Ying Gao

Journal of Electrochemistry

The polyaniline-carbon (PAnC) electrode was prepared by the polymerization of aniline monomer and activated carbon in ice water bath, and followed by chemical deposition of manganese dioxide MnO₂-PAnC composite material. The specific capacitance of MnO₂-PAnC reached 459 F•g^-1. The cyclic voltammetric results showed a small deformation in the voltammogram curve obtained with the MnO₂-PAnC electrode at high scan rate, indicating good reversibility and capacitive properties. The AC impedance results revealed that the MnO₂-PAnC electrode displayed the smallest charge transfer resistance and the fastest diffusion
rate of surface ions than other …

Preparation Of Co3O4/Ti Electrocatalytic Membrane Electrode For Catalytic Oxidation Of Benzyl Alcohol, Yu-Mei Zheng, Zhen Yin, Hong Wang, Jian-Xin Li

Journal of Electrochemistry

The cobalt oxide(Co₃O₄) nanoparticles were loaded on microporous Ti membrane to prepare Co₃O₄/Ti electrocatalytic membrane electrode by dip-coating method. The microstructures and electrochemical properties of Co₃O₄/Ti electrocatalytic membrane were investigated. The Co₃O₄/Ti electrocatalytic membrane reactor (ECMR) assembled by using the Co₃O₄/Ti electrocatalytic membrane as an anode was adopted for catalytic oxidation of benzyl alcohol to produce benzaldehyde and benzoic acid.The effects of different operation parameters on benzyl alcohol conversion, and selectivity to benzaldehyde and benzoic acid of ECMR were studied. …

Simulation Analysis In Dynamic Performance Of Proton Exchange Membrane Fuel Cell Under Starting Condition, Yan Xiao, Ying-Jie Chang, Wei Zhang, Qiu-Hong Jia

Journal of Electrochemistry

Based on the equivalent circuit model, by considering both the dynamic gas pressure model and the dynamic heat transfer model, a lumped parameter model is developed. The start process of the fuel cell is simulated by using SIMULINK software. The undershoot of the voltage is observed from the simulation results, and the response time of the voltage is basically the same as that of the fuel cell temperature, which indicates that the temperature has great influence on the dynamic performance of the fuel cell. From the perspective of the temperature, the dynamic responses of the thermodynamic potential, the activation overvoltage, …

Interaction Between Energy And Electrocatalysis —— A Review On The 1st Young Scientist Forum On Energy Electrocatalysis, Hong Li, Wen-Bin Cai

Journal of Electrochemistry

No abstract provided.

Synthesis And Electrochemical Properties Of Li3V2(Bo3)3/C Anode Materials For Lithium-Ion Batteries, You Wang, Yi-Wen Zeng, Xing Zhong, Xing Liu, Quan Tang

Journal of Electrochemistry

The Li₃V₂(BO₃)₃/C (LVB/C) composite materials were successfully synthesized in two steps:Firstly, a stoichiomertric mixture of Li₂C₂O₄, V₂O₅, H₃BO₃, H₂C₂O₄•H₂O and ethanol was thoroughly ball-milled to get the precursors. Secondly, the precursors were post-calcinated to get the ultimate products. The calcination temperatures of 750 ℃, 800 ℃ and 850 ℃ were selected based on TG-DTA analyses. The crystal structures, surface morphologies and carbon contents of the samples calcinated at five conditions, …

Effects Of Rotating Magnetic Fields On Pem Fuel Cell Performance, Mao-Liang Wu, En-Ze Wang, Guang-De Pan, Zhong-Jun Liu, Fei Xie

Journal of Electrochemistry

Proton Exchange Membrane (PEM) fuel cell performance may be improved by application of additional magnetic fields. In this work, one square permanent magnet, made of either 16 combination cylinder magnets with homopolarity or 16 combination cylinder magnets with heteropolarity, was exerted on the fuel cell surface to produce additional magnetic field affecting PEM fuel cell performance. The influences of magnetic field status (rotating, static and none) on polarization and power density curves measured in a PEM fuel cell were investigated. The results verified the benefit of magnetic field, proving that the magnetic field distribution could improve the fuel cell output. …

Multienzyme Immobilized Polymeric Membrane Reactor For The Transformation Of A Lignin Model Compound, Rupam Sarma, Md. Saiful Islam, Mark P. Running, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

We have developed an integrated, multienzyme functionalized membrane reactor for bioconversion of a lignin model compound involving enzymatic catalysis. The membrane bioreactors were fabricated through the layer-by-layer assembly approach to immobilize three different enzymes (glucose oxidase, peroxidase and laccase) into pH-responsive membranes. This novel membrane reactor couples the in situ generation of hydrogen peroxide (by glucose oxidase) to oxidative conversion of a lignin model compound, guaiacylglycerol-β-guaiacyl ether (GGE). Preliminary investigation of the efficacy of these functional membranes towards GGE degradation is demonstrated under convective flow mode. Over 90% of the initial feed could be degraded with the multienzyme immobilized membranes …

Uncertainty Evaluation In The Design Of Structural Health Monitoring Systems For Damage Detection, Christine M. Schubert Kabban, Richard P. Uber, Kevin J. Lin, Bin Lin, M. Bhuiyan, Victor Giurgiutiu

Faculty Publications

The validation of structural health monitoring (SHM) systems for aircraft is complicated by the extent and number of factors that the SHM system must demonstrate for robust performance. Therefore, a time- and cost-efficient method for examining all of the sensitive factors must be conducted. In this paper, we demonstrate the utility of using the simulation modeling environment to determine the SHM sensitive factors that must be considered for subsequent experiments, in order to enable the SHM validation. We demonstrate this concept by examining the effect of SHM system configuration and flaw characteristics on the response of a signal from a …

Evolution Of Mg Az31 Twin Activation With Strain: A Machine Learning Study, Andrew D. Orme

Undergraduate Honors Theses

Machine learning is being adopted in various areas of materials science to both create predictive models and to uncover correlations which reveal underlying physics. However, these two aims are often at odds with each other since the resultant predictive models generally become so complex that they can essentially be described as a black box, making them difficult to understand. In this study, complex relationships between microstructure and twin formation in AZ31 magnesium are investigated as a function of increasing strain. Supervised machine learning is employed, in the form of J-48 decision trees. In one approach, strain is incorporated as an …

Dynamic Behavior Of Materials, Jeremy Floyd, Andrew Minor

Research Horizons Day Posters

No abstract provided.

Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler

Public Land & Resources Law Review

In Hawai’i Wildlife Fund v. County of Maui, the Ninth Circuit held that the plain language of the Clean Water Act provides jurisdiction over indirect discharges of pollutants from a point source into groundwater that is shown to be connected to navigable waters. The court found that studies confirmed pollutants entering the Pacific Ocean were fairly traceable to the County of Maui’s sewage disposal wells. In affirming the district court’s ruling, the Ninth Circuit held that Maui County violated the Clean Water Act by discharging pollutants into a navigable water without the required permit. The court also concluded the …

The Application Of The Peleg Model In Order To Obtain Completely Soluble Materials For Food Product Packaging, Roxana Puscaselu (Gheorghita), Sonia Amariei

Journal of Applied Packaging Research

The aim of this study was to create a completely hydrosoluble edible films based on biopolymers that can be used as packaging material for powdered foods.10 edible films were obtained from various mixtures of hydrocolloids (agar, starch, sodium alginate) plasticized with glycerol and water. To assess their solubility, it was used the Peleg model which confirmed that increasing the temperature of the hydration medium, increases the water absorption rate. The sample obtained from agar and starch was less hydrophilic than sample with a high amount of sodium alginate, which was completely soluble after 3 minutes maintenance in 20° water. To …

From Flasks To Applications: Design And Optimization Of Giant Quantum Dots Using Traditional And Automated Synthetic Methods, Christina J. Hanson

Nanoscience and Microsystems ETDs

Semiconducting nanocrystals, also known as quantum dots (QDs), that emit light with near-unity quantum yield and are extremely photostable are attractive options as down-conversion and direct electricity-to-light materials for a variety of applications including solid-state lighting, display technologies, bio-imaging and optical tracking. Standard QDs with a core/thin shell structure display fluorescence intermittency (blinking) and photobleaching when exposed to prolonged room temperature excitation for single dot measurements, as well as significant reabsorption and energy transfer when densely packed into polymers or at high solution concentrations.

We have developed thick shell “giant” QDs (gQDs), ultra-stable photon sources both at the ensemble and …

Nanostructured Materials Derived From Metal-Organic Frameworks For Energy And Environmental Applications, Zhiqiang Xie

LSU Doctoral Dissertations

Nowadays, energy and environmental issues have become the top priority among a series of global issues. Fossil fuels as the dominant source are depleted fast and usually lead to some environmental problems. Heavy metal pollution has posed a severe threat to environment and public health. Metal-organic frameworks (MOFs), as a very promising category of porous materials, have attracted more and more interest in research communities due to their extremely high surface areas, diverse nanostructures and unique properties. To meet the ever-increasing energy demand and tackle the heavy metal pollution in water, MOFs can function as ideal templates to prepare various …

Scalable Patterning Using Laser-Induced Shock Waves, Saidjafarzoda Ilhom, Khomidkhodza Kholikov, Peizhen Li, Claire Ottman, Dylan Sanford, Zachary Thomas, Omer San, Haluk E. Karaca, Ali O. Er

Mechanical Engineering Faculty Publications

An advanced direct imprinting method with low cost, quick, and minimal environmental impact to create a thermally controllable surface pattern using the laser pulses is reported. Patterned microindents were generated on Ni₅₀Ti₅₀ shape memory alloys and aluminum using an Nd: YAG laser operating at 1064 nm combined with a suitable transparent overlay, a sacrificial layer of graphite, and copper grid. Laser pulses at different energy densities, which generate pressure pulses up to a few GPa on the surface, were focused through the confinement medium, ablating the copper grid to create plasma and transferring the grid pattern onto …

Review Of Challenges And Advances In Modification Of Food Package Headspace Gases, Ziynet Boz, Bruce A. Welt, Jeffrey K. Brecht, William Pelletier, Eric Mclamore, Gregory A. Kiker, Jason E. Butler

Journal of Applied Packaging Research

Modified Atmosphere Packaging (MAP) has been widely used as an effective way to preserve foods. Fresh produce, meat and meat products, seafood, and dairy products can benefit from modified gaseous atmospheres, which are usually achieved by reducing oxygen and increasing carbon dioxide concentrations, within limits, defined by product tolerances. MAP of fresh produce is particularly challenging because products are living and respiring. Respiration rates depend on several factors including temperature, oxygen, and carbon dioxide concentrations. Balancing package permeation with respiration is challenging, often due to limited selection of practical packaging materials. Failing to remain within tolerance limits of products leads …

Waste Management By Waste: Removal Of Acid Dyes From Wastewaters Of Textile Coloration Using Fish Scales, S M Fijul Kabir

LSU Master's Theses

Removal of hazardous acid dyes by economical process using low-cost bio-sorbents from wool industry wastewaters is of a pressing need, since it causes skin and respiratory diseases and disrupts other environmental components. Fish scales (FS), a by-product of fish industry, a type of solid waste, are usually discarded carelessly resulting in pungent odor and environmental burden. In this research, the FS of black drum (Pogonias cromis) were used for the removal of acid dyes (acid red 1 (AR1), acid blue 45 (AB45) and acid yellow 127 (AY126)) from wool industry wastewaters by absorption process with a view to …

Efficiency Of Solid Inclusion Removal From The Steel Melt By Ceramic Foam Filter: Design And Experimental Validation, Soumava Chakraborty, Ronald J. O'Malley, Laura Bartlett, Mingzhi Xu

Materials Science and Engineering Faculty Research & Creative Works

An investigation was performed to measure the efficiency of solid alumina inclusion removal by filtration during casting. A mold design was developed using modeling software to produce two castings that fill simultaneously, one with a filter and the other without a filter. The design avoided vortex formation and thus air entrainment, which helped to avoid reoxidation inside the mold cavity. Samples from these castings were analyzed utilizing an SEM/EDS system with automated feature analysis (AFA) to measure the efficiency of inclusion removal using a 20 ppi zirconia foam filter. This study also documents the occurrence of inclusion flotation and agglomeration …

Characterization Of Magnetic Thin Films Using The Magneto Optic Kerr Effect, Nicholas J. Savino

Student Scholar Showcase

Understanding magnetic properties of materials allows for advances in applications such as data storage. The Magneto-Optic Kerr Effect (MOKE) displays the reflective response a magnetic material has to a magnetic field. When polarized light reflects off of a magnetic material, the polarization orientation can change. The application of an external magnetic field can affect how much this polarization changes in a non-linear manner. Hysteresis loops are created when examining the relationship between intensity of the reflected light to the applied magnetic field provide information about magnetic properties of that material, such as the coercive field and field retention. Preliminary measurements …