Engineering Science and Materials Commons^™

Sn-Doped Α-Fe2O3 Photocatalyst Containing Oxygen Vacancy For Water-Splitting, Zu-Hua Wang, Dong-Fang Niu, Hui-Cheng Li, Rong-Bin Du, Heng Xu, Xin-Sheng Zhang

Journal of Electrochemistry

The α-Fe₂O₃ nanoparticles containing oxygen vacancies were synthesized in atmospheric N₂ by dip-dropping method without a high vacuum employed before annealing. The influences of annealing atmosphere and Sn-doping on the photocatalytic performance of α-Fe₂O₃ nanoparticles were studied by annealing the photocatalyst in N₂ or air and adding SnCl₄ to the precursor directly. The results showed that the current density of Sn-doping α-Fe₂O₃ annealed in N₂ at 550 °C and 1.23 V (vs. RHE) was 35 times greater than that of pristine α-Fe₂O₃ annealed in …

Preparation And Electrochemical Properties Of Attapulgite-Supported Nitrogen-Doped Carbon@Nico2O4 Composites For Supercapacitors, Hui Wan, Zong-Rong Ying, Xin-Dong Liu, Jian-Jian Lu, Wen-Wen Zhang

Journal of Electrochemistry

In this work, the attapulgite-supported nitrogen-doped carbon (ANC) was prepared by in-situ chemically polymerizing polyaniline coating upon attapulgite, followed by high temperature heat treatment, and then NiCo₂O₄was reacted onto the surface of ANC by a combination of hydrothermal reaction and calcination to synthesize ANC@NiCo₂O₄ composites. The chemical composition and morphology of the samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N₂ adsorption/desorption. The electrochemical properties were evaluated by means of constant current charge discharge (GCD) and cyclic voltammetry (CV). …

Preparations Of Mno2 Reference Electrodes For Corrosion Monitoring Of Reinforced Concrete, Li Yang, Bing Xu, Hai Wang, Ze-Hua Dong

Journal of Electrochemistry

In this work, the solid reference electrode was assemblied by using the electrochemically synthesized manganese dioxide (MnO₂) (EMD) powder, gel electrolyte and thin mortar layer for the durability evaluation of concrete. The EMD reference electrode exhibited higher potential stability (< 10 mV drift) than the chemically synthesied MnO₂ (CMD) based on half year potential tests in the saturated Ca(OH)₂ solution and hardened mortar. In addition, the EMD electrode was almost insensitive to the presences of chloride ion and corrosion inhibitor. Electrochemical impedance and polarization curves indicate that the EMD electrode had lower charge transfer resistance,higher exchange current density and lower temperature coefficient than the …

An Investigation In The Performance Of Lithium Sulfur Battery With A Tic Coated Separator, Jian-Hua Fang, Yong Cao, Mao-Ping Yang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

To improve the specific capacity and cycle stability of lithium-sulfur (Li-S) battery, a TiC/Celgard coating separator was developed and its performance in Li-S battery was investigated. The electrochemical test results confirmed that the TiC coating layer could significantly increase the capacity and cycle stability. At a high rate of 2C, it still delivered the capacity of 650 mAh·g^-1. At 0.5C, the specific capacity was maintained at 841.3 mAh·g^-1 after 100 cycles.

Direct Electrochemistry Of Glucose Oxidase Based On Ws2 Quantum Dots And Its Biosensing Application, Chen-Lu Li, Hua-Ping Peng, Zhong-Nan Huang, Yi-Lun Sheng, Pei-Wen Wu, Xin-Hua Lin

Journal of Electrochemistry

In this study, a novel electrochemical glucose biosensor has been developed by immobilizing glucose oxidase (GOx) on tungsten disulfide quantum dots (WS₂ QDs) on the surface of glassy carbon electrode (GCE). Transmission electron microscopy, UV-vis spectroscopy and cyclic voltammetry were employed to characterize the morphology, structure, and electrochemical behaviors of the as-prepared WS₂ QDs and the biofilm modified electrode. The results suggested that the WS₂ QDs could accelerate the electron transfer between the electrode and the immobilized enzyme, which enabled the direct electrochemistry of GOx without any electron mediator. Besides, the immobilized GOx in WS₂ QDsfilm …

Application Of Adamantane Schiff Base Nickel Complexes/Graphene Oxide/Glassy Carbon Modified Electrode In Detection Of Carmine, Peng Guo, Zheng Liu, Hai-Ying Li, Li-Ming Ma

Journal of Electrochemistry

The Schiff base nickel complexes/graphene oxide/glassy carbon electrodes were prepared by embedded method and electrodeposition on which were used to quantitatively detect the contents of carmine. Cyclic voltammetry, chronoamperometry, scanning electron microscopy (SEM) and other methods were employed to characterize properties and morphologies of the modified electrodes. The results show that the adamantane double Schiff base nickel complexes/graphene oxide/glassy carbon electrode had high electric catalytic activity toward carmine oxidation reaction, and might provide an easy and quick way to detect carmine content with good reproducibility.

Tensile Specimen Punch, John Allen

All Undergraduate Projects

This project comes from a need to have tensile specimens made for the MET 351, Metallurgy/Materials and Processes, and 426, Applied Strengths of Materials, labs. This punch is designed to be used with an arbor press to create the desired tensile specimen shape out of plastic blanks. The initial concept was suggested by Dr. Craig Johnson. The designs went through many changes, for example getting rid of the sides originally proposed to hold the specimen in place, and modifications to other parts to make them more efficient. Additional parts were also added to the design with the help and advice …

Detecting Laminate Damage Using Embedded Electrically Active Plies – An Analytical Approach, Amany Micheal, Yehia Bahei-El-Din

Centre for Advanced Materials

Assessment of damage initiation and progression in composite laminates with embedded electrically active plies is modeled. Utilizing electrically active layers embedded in composite laminates as damage sensors is proposed by several researchers and is mainly assessed experimentally. Sensing damage using embedded electrically active plies is generally preferred over the use of surface mounted PZT wafers since the range of the latter is limited to a very narrow area underneath the surface, while multiple damage mechanisms can generally be found in several plies of the laminate. The solution presented invokes two levels of analysis. Firstly, on the laminate level, applied membrane …

Built-In Bicycle Rack For Cars, Scott A. Hansberry

All Undergraduate Projects

Transporting a bicycle after riding somewhere and then needing to be pickup can be problematic. Bicycles will not fit in most vehicles without removing components. There is also the risk of damaging the inside of the vehicle. Expecting everyone to have a bike rack for their vehicle is unrealistic because the bike rack could be considered unappealing visually, take up to much space in the trunk, or limit the vehicle owner’s access to the trunk. The solution to this problem is a bike rack that mounts onto your car and then mounts your bike onto the rack. Most people don’t …

Anisotropy Evolution Due To Surface Treatment On 3d-Printed Fused Deposition Modeling (Fdm) Of Acrylonitrile Butadiene Styrene (Abs), Blake E. Lozinski

Honors Undergraduate Theses

Purpose: This paper will present insight to the methodology and results of the experimental characterization of Acrylonitrile Butadiene Styrene (ABS) using Fused Deposition Modeling (FDM). The work in this research explored the effects of print orientation, surface treatment, and ultraviolet (UV) light degradation with the utilization of Digital Image Correlation (DIC) on ABS tensile specimens.

Design/methodology: ABS specimens were printed at three build orientations (flat (0 degrees), 45 degrees, and up-right (90 degrees)). Each of these specimens were treated with three different surface treatments including a control (acrylic paint, Cyanoacrylate, and Diglycidyl Bisphenol A) followed by exposure to UV light …

Compact Facility For Testing Steady And Transient Thermal Performance Of Building Walls, Aimee Byrne, Gerard Byrne, Anthony Robinson

Articles

Energy efficiency retrofit of buildings represents a key effort in reducing EU energy demand by 20% by 2020. However, predictions tend to overestimate savings by large percentages. The shortfall in savings can be attributed to incorrect predictive techniques, comfort takeback along with other behavioural and workmanship variables. Common predictive techniques related to heat loss tend to be based on the U-value of the building envelope. This paper presents the design of a more straightforward and compact version of the traditional Hot-Box apparatus (measures U-value) which instead determines the thermal resistance of samples of building envelope. U-value includes the need to …

Comparison Of Extruder Systems For 3d Printer Filament Fabrication, Adriana Ramirez

Open Access Theses & Dissertations

Additive Manufacturing (AM) has grown in popularity over the past thirty years, due to its versatility, short design to product cycle, and capability to fabricate complex geometries, which cannot otherwise be produced. There exist several platforms that are able to print objects composed of different materials, making this technology significant in different fields such as: automotive, aerospace, medical, electronics, amongst others. Though several types of AM technologies are available, the expiration of the patents on fused deposition modeling (FDM) in 2009 has led to a widespread use of this platform in academia and home use settings.

Widespread use of FDM-type …

Material Behavior Of Window 7 Carrier Panel Tiles And Thermal Pane Fragments Recovered From The Space Shuttle Columbia, Brenda Roseanne Arellano

Open Access Theses & Dissertations

Since the end of the space shuttle program, a new generation spacecraft has been developed to transport humans back into space. NASAâ??s Orion will carry a crew beyond low-earth orbit and the exploration of Mars may be possible in the future. Space safety becomes significant with human spaceflight and the risks are high. However, aerospace materials may provide opportunities to prevent future disasters. When the space shuttle Columbia disintegrated during re-entry in 2001, thousands of debris were collected for analysis. In contrast, when the Challenger space shuttle broke apart in 1986, all shuttle debris were buried. These tragic disasters are …

The Interplay Between Grain Size And Austenite Stability On Deformation Behavior Of High Strength-High Ductility Combination Nanostructured Stainless Steel, Venkata Sai Ananth Challa

Open Access Theses & Dissertations

The concept of phase reversion involving severe cold deformation of metastable austenite to generate strain-induced martensite, followed by temperature-time annealing sequence, was used to obtain varying grain size from nanograined/ultrafine-grained (NG/UFG) to coarse-grained (CG) regime. This concept was used to obtain â??high strength-high ductilityâ?? combination in nano/ultrafine-grained (NG/UFG) austenitic stainless steel. Using this concept, the objective of the study is to elucidate the dependence of grain size on deformation mechanisms and deformation-induced microstructural changes. The objective was accomplished by combining depth-sensing nanoindentation experiments conducted at various strain rates, and interrupted tensile testing at various strain and post-mortem analyses of deformed …

Dft Study Of Adsorption Of Trimetallic Endohedral Fullerenes On Graphene, Nakul Nitin Karle

Open Access Theses & Dissertations

A density functional theory (DFT) study on the geometric and electronic structure of C60 and Sc3N@C80 along with their adsorption on pristine single layer graphene (SLG) is presented. C60 is found to adsorb in two nearly degenerate configurations: (i) with a pentagon facing the SLG, which is the most stable one, and (ii) with a hexagon facing the SLG in a face-to-face perfect alignment, rarely common in Ï?â??Ï? interactions, 0.06 eV higher in energy. The calculated binding energy of 0.76 eV, which includes dispersion effects, is in good agreement with previous theoretical and experimental reports. On the contrary, Sc3N@C80 adsorption …

Process-Structure-Property Relationship In Magnesium-Based Biodegradable Alloy For Biomedical Applications, Pramanshu Trivedi

Open Access Theses & Dissertations

Magnesium alloys are considered to be the next generation of biomaterials because of their ability to degrade in the physiological environment. We elucidate here the impact of multiaxial forging of Mg-2Zn-2Gd alloy on grain refinement to sub-micron regime and relate the structure to mechanical properties and biological functionality. As-cast and annealed samples were multiaxial forged (MAF) for a total number of two passes with a true strain of ~2/pass. Considering that the microstructure governs the biological response of materials, we studied the constituents of the microstructure in conjunction with the mechanical behavior. The antimicrobial behavior in a Mg-2Zn-2Gd alloy with …

Electronic Structure Studies On Transition Metal Containing Endohedral Fullerenes, Carbon Onions And Zinc Sulfide Cages, Shusil Bhusal

Open Access Theses & Dissertations

We present the most stable structures for VXSc3-XN@C2n (where X=1-3 and 2n=70, 76, 78 and 80) using a systematic procedure that involves all possible isomers of the host fullerene cages. Subsequently, a detailed investigation of structural and electronic properties of the lowest energy isomers is performed using density functional theory in combination with large polarized Gaussian basis sets. The search procedure developed involved structural optimizations of thousands of fullerenes and correctly identifies the experimentally observed VSc2N@C80 and V2ScN@C80 isomer as the most stable structures. The structural analysis shows that a few V-doped endohedral fullerenes do not follow the isolated pentagon …

Organic-Inorganic Graphite And Transition Metal Dichalcogenide Based Composites For 3d Printing, Jorge Alfredo Catalan Gonzalez

Open Access Theses & Dissertations

This project was multipronged to help fuse together topics of additive manufacturing and two-dimensional (2D) layered materials, and studying the mechanical and electrical properties of the composites produced. The composites are made from the thermoplastic polymer acting as a matrix and the graphite and 2D transition metal dichalcogenides (TMDs) serving as the filler or reinforcement. Different concentrations of TMD's were added to the matrix to study the effect of composition on the mechanical and electrical properties. To shed insights into the mechanical properties, test coupons were produced as "dog bone" structures for tensile testing using the ASTM D638 type 5 …

Mechanically Activated Magnesiothermic Combustion Synthesis Of Zirconium And Hafnium Diborides, Sergio Cordova

Open Access Theses & Dissertations

Magnetohydrodynamic (MHD) generation of electric power has the potential to increase the thermal efficiency of fossil-fuel burning power plants. Electrode materials in MHD generators must possess a high melting point, high electrical and thermal conductivities, chemical stability, and resistance to thermal shock, oxidation, and plasma sparks/arcs. Ultra-high temperature ceramics based on diborides of zirconium and hafnium (ZrB2 and HfB2) are promising materials for this application. Self-propagating high-temperature synThesis (SHS) is an attractive method for their large-scale fabrication, but SHS of ZrB2 and HfB2 from elemental Zr, Hf, and B is not economically viable because of the high cost of the …

Methods For Producing Graphene From Petroleum By-Products, Eva M. Deemer

Open Access Theses & Dissertations

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On Demand 3d Printed Hybrid Scaffolds For Tissue Engineering Applications, Ivan D. Hernandez

Open Access Theses & Dissertations

A composite 3D printed polymer scaffold with inbuilt porosity and filled with a hydrogel can provide an ideal support system for cell growth, proliferation, and vascularization. Therefore, a hybrid system of 3D printed polycaprolactone (PCL) scaffold and a hydroxyapatite-based hydrogel was developed for application in the reconstruction of bone defects, which are inherently difficult to repair without any guided therapies. In the present study, a 3D printed gyroid structure of PCL allowed the loading of a higher amount of hydrogel as compared to conventionally used 3D printed mesh structure of the same volume and strut thickness. The hydrogel was composed …

Ac Susceptibility And Epr Investigations Of Superspin Dynamics In Manganese Oxide Nanoparticles, Mahesh Koirala

Open Access Theses & Dissertations

We have investigated the superspin dynamics of 5 nm and 10 nm mixed state Mn3O4 nanoparticles utilizing ac-susceptibility and electron paramagnetic resonance measurements. The out of phase component of the ac-susceptibility measurements show a magnetic anomaly below (T

Protonic Conductors For Intermediate Temperature Fuel Cell Electrolytes: Superprotonic Csh2po4 Stabilization And In-Doped Snp2o7 Structure Study, Heber Jair Martinez Salinas

Open Access Theses & Dissertations

Proton conductor solid electrolytes CsH2PO4 and In-doped tin pyrophosphate have been investigated as candidates to fill a gap of suitable electrolytes for fuel cells at the intermediate temperature range due their unusually high conductivities between 200 and 300 °C. Unfortunately, in the case of CsH2PO4, complicated experimental conditions, like a humidified environment, or high pressure, are needed to preserve the sought high conducting phase.

In the first stage of this work, X-ray diffraction on CsH2PO 4 samples performed in air, and under normal conditions of humidity and pressure, evidence of the cubic phase of CsH2PO4 was observed during short intervals …

Structural And Mechanical Characterization Of Nanocrystalline Tungsten And Tungsten-Based Alloy Thin Films For Extreme Environment Applications, Gustavo Martinez

Open Access Theses & Dissertations

Extreme environments associated with nuclear applications often results in degradation of the physical, mechanical and thermo-mechanical properties of the materials. Tungsten (W) exhibits unique physical and mechanical properties, which makes tungsten a good candidate for nuclear applications; however, intrinsic W exhibits low fracture toughness at all temperatures in addition to a high ductile to brittle transition. In the present work, nanocrystalline W, W-Y and W-Mo alloys were nanoengineered for nuclear applications. Nanocrystalline tungsten coatings with a thickness of ~1 µm were deposited onto Silicon (100) and Sapphire (C-plane) using RF and DC sputtering techniques under various growth conditions. Yttrium content …

Raman Microscopic Analysis Of Internal Stress In Boron-Doped Diamond Thin Films, Emma M.A. Sundin

Open Access Theses & Dissertations

The correlations between induced stress on undoped and boron-doped diamond (BDD) thin films, sample chemical composition, and fabrication substrate are investigated in this study via confocal Raman microspectroscopic analysis. Stability of BDD films is relevant to fast-scan cyclic voltammetry, as film delamination and dislocation of BDD-coated electrodes that can occur during neurosurgical electrode implantation can negatively impact the biosensing reliability of this technique. Electrodes were fabricated by coating cylindrical tungsten rods using a custom-built chemical vapor deposition reactor. The results of the analysis reveal a direct correlation between regions of pure diamond and enhanced material stress, as well as preferential …

Structural And Electrical Characterization Of Tin Oxide Resistive Switching, Arka Talukdar

Open Access Theses & Dissertations

Resistive switching in metal oxide is a phenomenon in which the metal oxide changes its resistance upon application of electric field and thus giving two states; high resistance state (HRS) and low resistance state (LRS). Many metal oxides have been investigated however very little is known about unipolar resistive switching in SnO2 though it has shown excellent resistive switching characteristics. Defects in the material play a vital role in resistive switching of the metal oxides. In this work, the role of defects in resistive switching of SnO2 are investigated in Ti/SnO2/Au structures. Two methods were used to control the concentration …

Comprehensive Finite Element Modeling Of Ti-6al-4v Cellular Solids Fabricated By Electron Beam Melting, Edel Arrieta

Open Access Theses & Dissertations

Additive manufacturing permits the fabrication of cellular metals which are materials that can be highly customizable and possess multiple and extraordinary properties such as damage tolerance, metamorphic and auxetic behaviors, and high specific stiffness. This makes them the subject of interest for innovative applications. With interest in these materials for energy absorption applications, this work presents the development of nonlinear finite element models in commercial software platforms (MSC Patran/Nastran) that permit the analysis of the deformation mechanisms of these materials under compressive loads. In the development of these models, a detailed multiscale study on the different factors affecting the response …

Characterization & Extraction Of Extracellular Matrix From Porcine Adipose Tissue, Rahulkumar Kantibhia Bhoi

Open Access Theses & Dissertations

Tissue in particular extracellular matrix(ECM) plays a vital role in the growth and the function of each cell types and promote tissue regeneration and repair an impair organs. Many techniques have been developed so far to decellularized porcine tissue for the purpose to use as regenerative medicine and in tissue engineering. We aimed to optimized a method to decellularized porcine tissue while effectively eliminating xenogeneic epitopes, lipids and to retain necessary component of it intact without disrupting ECM. We have developed 2-week protocol to optimize well preserved ECM component that may keep xenogeneic biomaterial for tissue engineering and regenerative medicine. …

Impact Of Clip Connection And Insulation Thickness On Bracing Of Purlins In Standing Seam Roof Systems, Michael W. Seek, Daniel Mclaughlin

Engineering Technology Faculty Publications

The flexural strength of purlins in standing seam roof systems is highly dependent upon the extent to which the sheathing provides lateral and torsional restraint. Typical models to predict the restraint provided by the sheathing assume that the plane of lateral resistance occurs at the top flange of the purlin. In reality, depending on the configuration of the clip and the amount of insulation located between the purlin and the clip, the plane of lateral resistance and corresponding center of rotation shifts above the top flange. This distance, referred to as the effective standoff, is important to evaluate the effectiveness …

Lithium-Sulfur (Selenium) Batteries: Interface Issues And Solving Strategies, Nian-Wu Li, Ya-Xia Yin, Yu-Guo Guo

Journal of Electrochemistry

The stable interface is still a challenge for lithium-sulfur (selenium) batteries because of the low conductivity of sulfur (selenium), dissolution of polysulfide (polyselenide), volume expansion of sulfur (selenium), and lithium dendrite growth. This review describers some recent developments in lithium-sulfur (selenium) batteries and highlights our efforts in this field. The possible strategies for building stable interface in the lithium-sulfur (selenium) batteries including nano-restriction effect, chemical bonding, interface adsorption, surface coating, electrolyte optimization, and Lithium anode treatment have been discussed.