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Articles 1 - 30 of 228
Full-Text Articles in Engineering
Effect Of The Microstructure On The Corrosion Behavior Of Alcunimn And Alcunimnsi High Entropy Alloys In A 3.5wt% Nacl Solution, Celine Chiong
Effect Of The Microstructure On The Corrosion Behavior Of Alcunimn And Alcunimnsi High Entropy Alloys In A 3.5wt% Nacl Solution, Celine Chiong
Open Access Theses & Dissertations
In this study, the AlCuNiMn and AlCuNiMnSi high entropy alloys (HEAs) are investigated to characterize the effect of Si addition and subsequent annealing treatments on the corrosion behavior in a 3.5wt% NaCl solution at room temperature. The microstructure evolution from the as-received condition and after annealing at 600°C, 800°C, and 1000°C for 24 hours in air is examined. The microstructural transformation of HEAs is extensively reported in the literature. However, its impact on the corrosion resistance of HEAs has not received the same attention. In this study, an increase in the annealing temperature of the base AlCuNiMn alloy improved the …
Analysis Of Additively Manufactured Inconel 718 Combustion Behavior In Promoted Oxygen Environments, Dominic George Dieguez
Analysis Of Additively Manufactured Inconel 718 Combustion Behavior In Promoted Oxygen Environments, Dominic George Dieguez
Open Access Theses & Dissertations
Promoted combustion testing is a vital tool for engineers to establish the combustion and flammability characteristics of materials (metallic or otherwise) in oxygen enriched environments. Historically, much of the established data for metallic promoted combustion has been with regards to materials in their cast and wrought forms. However, with the emergence of additive manufacturing as a preferred method of fabrication, the need exists to evaluate how metals in that form behave. Recent testing has demonstrated that even if a metal or alloy is nominally the same with regards to chemistry, flammability between samples in the wrought form can differ significantly …
Laser Powder Directed Energy Deposition (Lp-Ded) Inconel 718: Laser Power And Heat Treatment Effect On Microstructure And Mechanical Properties, Dana Victoria Godinez
Laser Powder Directed Energy Deposition (Lp-Ded) Inconel 718: Laser Power And Heat Treatment Effect On Microstructure And Mechanical Properties, Dana Victoria Godinez
Open Access Theses & Dissertations
This study examines the microstructure and mechanical properties (tensile, hardness, and fatigue endurance) of laser powder-directed energy deposition (LP-DED) printed specimens with varying deposition parameters. Five samples with power inputs ranging from 350 to 2620W, all of similar thicknesses, were evaluated to enable a direct comparison. The varying specimens were heat treated, including stress relief, hot isostatic pressing, solution, and two-step aging. The resulting microstructures and their corresponding hardness values were compared at each heat treatment stage. The fully heat-treated specimens' tensile properties and fatigue life were also examined and compared. Key findings of this study indicate that complete heat …
Earth Abundant Catalyst For Evironmental Sustainability Applications, Javier Hernandez
Earth Abundant Catalyst For Evironmental Sustainability Applications, Javier Hernandez
Open Access Theses & Dissertations
The development of experimental methodologies for synthesizing a diverse range of metallic and metal oxide nanoparticles tailored for sustainable water treatment applications was investigated. These nanoparticles are prepared using environmentally friendly and scalable synthesis methods, underscoring their potential for large-scale production. Synthesized nanoparticles are harnessed for various processes, including catalysis and electrocatalysis, with a primary objective of degrading and removing organic pollutants from water. Key to this research is the encapsulation of nanoparticles within solid supports. Multiple methodologies are explored to engineer supports that ensure nanoparticle stabilization, monodispersion, and prevent unintended release into the environment. Two alternative approaches were evaluated …
Feasibility Study For The Detection Of Damage To Composite Overwrapped Pressure Vessels With Phase Array Ultrasonic Testing, Jordan Scott Hitter
Feasibility Study For The Detection Of Damage To Composite Overwrapped Pressure Vessels With Phase Array Ultrasonic Testing, Jordan Scott Hitter
Open Access Theses & Dissertations
When discussing the field of Nondestructive Examination, there are various techniques and instrumentation that can be utilized for analysis of components. However, with newer technology and the development of newer forms of technique, it is critical to explore exactly how these can be applied. This work will aim to explore one newer technique, Phased Array Ultrasonic Testing, and determine the viability of its use for examining Composite Overwrapped Pressure Vessels (COPVs). Currently, the types of vessels have been used in a variety of ways such as in transportation vehicles. More notably, these vessels are used in aerospace applications hence the …
Microstructural Characterization And Oxidation Behavior Of Al-Cu-Ni-Mn And Al-Cu-Ni-Mn-Si Non-Body Centered Cubic High Entropy Alloys, Mckenna Mae Lin Hitter
Microstructural Characterization And Oxidation Behavior Of Al-Cu-Ni-Mn And Al-Cu-Ni-Mn-Si Non-Body Centered Cubic High Entropy Alloys, Mckenna Mae Lin Hitter
Open Access Theses & Dissertations
High entropy alloys (HEA) differ from traditional alloying systems because five elements are mixed in equi-atomic proportions, as opposed to having one main principal element. As a result of exploring this new method of alloying, it was found that high entropy alloys demonstrate exceptional mechanical properties, an example being oxidation resistance, and are capable of enduring elevated temperatures. Seeing the potential that this new area of interest contains, studies involving a combination of elements to form various HEA have been performed. Most refractory metals are body-centered cubic and possess extremely high melting temperatures, so they are regularly considered when designing …
Effect Of Multiple Machine Configurations And Wall Thickness On Microstructure And Microhardness Of Laser Powder Bed Fusion (L-Pbf) Additively Manufactured Heat-Treated Inconel 718 Products, Anannya Doris
Open Access Theses & Dissertations
This research examined thin section prototypes having seven nominal thicknesses ranging from 0.1 to 2.0 mm, composing a series of geometric feature build plates manufactured by multiple laser powder bed fusion (L-PBF) machine configurations. The build plates and thin section feature prototypes underwent a full heat treatment cycle per established standards: anneal at 1066°C, SR+HIP at 1163°C, and fully treat-treated by combining SR+HIP+solution treatment at 1066°C and double aging treatment at 760°C and 680°C, respectively. The fully heat-treated (FHT) Inconel 718 wall specimens were sectioned from 16 distinct geometric feature build plates constructed on 15 different L-PBF machines. The thin …
Ultrasonic Non-Destructive Evaluation Of Additively Manufactured Polymer-Ceramic Composites, Christian Alexander Ruiz
Ultrasonic Non-Destructive Evaluation Of Additively Manufactured Polymer-Ceramic Composites, Christian Alexander Ruiz
Open Access Theses & Dissertations
Digital light processing (DLP) is an attractive additive manufacturing technique due to its ability to create ceramic parts with complex geometries. DLP uses ultraviolet light to polymerize a slurry comprised of ceramic powder and photosensitive resin in layers to create solid parts. Printing parameters such as light intensity and exposure time are critical when producing these parts. Improper parameters can lead to over or under-curing, adversely impacting print quality and strength. Samples were printed at varying layer exposure times and then tested using ultrasonics to determine the degree of conversion. Additionally, ultrasonics were used as a non-destructive technique to obtain …
Development Of A 3d Printed Conductive Biopolymer For Cardiac Tissue Engineering, Britanny Lizeth Stark
Development Of A 3d Printed Conductive Biopolymer For Cardiac Tissue Engineering, Britanny Lizeth Stark
Open Access Theses & Dissertations
Cardiovascular disease (CVD) is the leading cause of death in the US, with approximately 859,000 deaths each year. The major contributor to CVD is Acute Myocardial Infarction (AMI), which causes the death of approximately 25% of the cardiomyocytes present in the left ventricle of the heart. After AMI, the adult human heart has a very limited regenerative capacity. Moreover, the electrical propagation of the myocardium is severely disrupted, making the heart more susceptible to failure and patient death. However, current pharmacological treatments do not address the loss of cardiomyocytes and the disruption of electrical propagation in the heart. Tissue engineering …
Upcyclying Of Polyethylene Terephtalate By Addition Of Thermoplastic Elastomer, Diego Francisco Bermudez
Upcyclying Of Polyethylene Terephtalate By Addition Of Thermoplastic Elastomer, Diego Francisco Bermudez
Open Access Theses & Dissertations
Continual overconsumption of single-use plastics has generated challenges of solid waste management across the United States. Common plastic waste management solutions, such as landfill, have caused the migration of contaminants into the environment consequently affecting not only the health of wildlife, but also that of human beings. Alternative strategies for the handling of single-use plastic such as polyethylene terephthalate (PET), used in the food packaging industry, can ultimately help mitigate the noxious consequences of single-use plastics affecting entire ecosystems. This study demonstrates a potential avenue of materials upcycling by studying the effects of coupling PET with the thermoplastic elastomer styrene-ethylene-butylene-styrene …
Characterization Of Fcc Al-Cu-Ni-Mn-Ag High Entropy Alloy, Gina Zavala Alvarado
Characterization Of Fcc Al-Cu-Ni-Mn-Ag High Entropy Alloy, Gina Zavala Alvarado
Open Access Theses & Dissertations
The effect of Ag on the microstructure developed in Al-Cu-Ni-Mn alloy has been determined. The modified Al-Cu-Ni-Mn alloy by Ag addition shows the presence of three microconstituents consisting of phases rich in (1) Cu, (2) Ni, and (3) Ag. The foregoing alloys heated for 24 hours from 600 to 1000 °C show excellent oxidation resistance. Oxide formation and microstructural changes of the alloy have been characterized by elemental mapping and X-ray diffraction (XRD). Results show that the elements of Al and Mn preferentially oxidize while Cu and Ni provide oxidation resistance to the alloy. Hardness was taken on the alloy …
Design And Development Of Transition Metal-Based Electrocatalysts For Environmentally Friendly And Efficient Hydrogen Evolution Reactions (Her), Navid Attarzadeh
Design And Development Of Transition Metal-Based Electrocatalysts For Environmentally Friendly And Efficient Hydrogen Evolution Reactions (Her), Navid Attarzadeh
Open Access Theses & Dissertations
Hydrogen fuel is a clean energy source primarily because it emits no carbon dioxide (CO2). Sustainable energy alternatives have attracted the scientific community and policymakers as concerns over global warming and depletion of fossil fuels have increased significantly. Substituting H2 gas as a primary source for our daily energy consumption under the guideline of the hydrogen economy concept has not progressed as anticipated because of inadequate efficiency associated with the generation (electrolyzer) and utilization (fuel cell) devices. However, there are challenges associated with hydrogen that must be overcome for it to become a truly sustainable and widespread energy source. The …
Double Cantilever Beam Mode-I Testing Validation In Large-Scale Additive Manufacturing Carbon Composite, Luis Alfonso Camacho
Double Cantilever Beam Mode-I Testing Validation In Large-Scale Additive Manufacturing Carbon Composite, Luis Alfonso Camacho
Open Access Theses & Dissertations
Testing for mechanical properties for additive manufacturing has been based on already existing standards for traditional manufacturing methods. For composites in large scale additive manufacturing there is a research gap in bond strength and fracture toughness for a single layer interface. By using Double cantilever beam Mode I, this thesis manuscript validates testing parameters and protocols to describe the intricacies of ABS matrix 20 wt.% carbon filled composite, specifically on the layer-to-layer interface. Studies suggest that fracture toughness is sensitive to process parameters, like deflection speed and sharpened crack tip at the layer interface of BAAM 3D printed part and …
Studies On Atomic And Molecular Properties Using Locally Scaled And Perdew-Zunger Self-Interaction Corrected Density Functional Approximations, Philip Adeniyi Oyedele
Studies On Atomic And Molecular Properties Using Locally Scaled And Perdew-Zunger Self-Interaction Corrected Density Functional Approximations, Philip Adeniyi Oyedele
Open Access Theses & Dissertations
This thesis examines some properties of atoms and molecules using one-electron self-interaction-correction (SIC) methods such as the Perdew-Zunger SIC (PZSIC) and the locally scaled SIC method of Zope and coworkers within the Fermi-Lowdin SIC formal- ism. The accuracy of electron density is examined by comparing moments of the den- sity, ⟨r^n⟩ = ∫ ρ(r)rndτ = ∫ ∞ 0 4πr2ρ(r)rndr (n = −2, −1, 0, 1, 2, 3) with the corresponding available values from the Coupled cluster (CC) singles, doubles, and perturbative triples (CCSD(T)) method. Three test sets are considered: boron through neon neutral atoms, two and four electron cations, and …
Electrochemical Approaches To Life-Support Resources In Space Missions And Nuclear Technologies: Hydrogen Peroxide And Uranium Films, Armando Manuel Pena-Duarte
Electrochemical Approaches To Life-Support Resources In Space Missions And Nuclear Technologies: Hydrogen Peroxide And Uranium Films, Armando Manuel Pena-Duarte
Open Access Theses & Dissertations
Space race has developed several technological advances that have achieved and continue to achieve the success of space missions in the aerospace timeline. Currently, the number of space technical and scientific innovations is still growing––demanding new materials and developments for extreme performing applications of fuel cells, batteries, supercapacitors, and systems of nuclear energy. Space missions require life-support solutions, auto-sustainable closed-loop living environments, cleaning and sanitizing solutions against pathogens, and safe nuclear-based resources of energy––with fissile materials with well-controlled dimensions within the core fuel elements. Likewise, to guarantee safety conditions, reduce costs, and facilitate operational logistics, space missions must reduce their …
Thermal Behavior Of Plain And Fiber-Reinforced Rigid Concrete Airfield Runways, Arash Karimi Pour
Thermal Behavior Of Plain And Fiber-Reinforced Rigid Concrete Airfield Runways, Arash Karimi Pour
Open Access Theses & Dissertations
The environmental condition and temperature gradient are important factors resulting in concrete airfield runways cracking during the time. Rigid concrete airfield runways experience different thermal gradients during the day and night due to changes in air temperature. Curling and thermal expansion stresses are the main consequences resulting in various types of cracking over the surface and thickness of concrete airfield runways and increasing maintenance costs. The curvature of concrete slabs increases with an increase in the temperature gradient which is amplified when runways open to traffic. Additionally, the combination of the curling and shrinkage stresses, in rare circumstances, can be …
Characterization Of Novel Self-Healing Polymer Blends For Additive Manufacturing, Truman James Word
Characterization Of Novel Self-Healing Polymer Blends For Additive Manufacturing, Truman James Word
Open Access Theses & Dissertations
This dissertation begins with an overview of novel polymer systems which have been developed by the Polymer Extrusion Lab at the University of Texas at El Paso. Many composite polymer systems have been created using many different polymers as well as ceramics and metals primarily in the form of powders added to the bulk polymer. The bulk of this work entails a study that was conducted to develop and characterize the mechanical, shape memory and self-healing properties of three polymer blends: polylactic acid (PLA) combined with maleated styrene-ethylene-butylene-styrene (SEBS-g-MA), acrylonitrile butadiene styrene (ABS) combined with maleated styrene-ethylene-butylene-styrene (SEBS-g-MA), and polylactic …
Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos
Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos
Open Access Theses & Dissertations
An interpenetrating polymer network (IPN) for cation exchange applications was synthesized from a blend of styrene-ethylene/butylene-styrene (SEBS) and acrylonitrile butadiene styrene (ABS), which was 3D printed, grafted with crosslinked polystyrene (PS), and sulfonated. A method for styrene grafting was applied to reduce the damage to polymer phases caused by the sulfonation reaction. Styrene and divinylbenzene monomers were introduced to the IPN and induced with heat treatment to polymerize in situ. The graft copolymerization reaction was enhanced with varying quantities of benzoyl peroxide as a chemical initiator. The samples were subsequently sulfonated with chlorosulfonic acid in dichloroethane and functionalized for ion …
Nano-Engineered Soft Magnets: Potential Application In Water Treatment, Hyperthermia And Molecular (Organic) Magnets, Yohannes Weldemariam Getahun
Nano-Engineered Soft Magnets: Potential Application In Water Treatment, Hyperthermia And Molecular (Organic) Magnets, Yohannes Weldemariam Getahun
Open Access Theses & Dissertations
Scrutinizing the remarkable and tunable properties of magnetic materials at a nanoscale size "There's Plenty of Room at the Bottom..." Richard Feynman, this study attempts to find sustainable solutions to some of the deteriorating environmental, health, and energy problems the world is encountering. Due to their simple preparation, surface adaptability, and tunable magnetic and optical properties, magnetic nanoparticles have been extensively investigated in water treatment, cancer therapy, data storage, and more. However, relying on non-reusable and chemical-based treatment agents in water, complex and costly cancer treatment procedures and molecular magnets that operate far below room temperature limited those attempts from …
The Qualification Of Sealability And Creep Relaxation Of Additively Manufactured Zytel Gaskets For Pem Fuel Cells, Robert Lazarin
The Qualification Of Sealability And Creep Relaxation Of Additively Manufactured Zytel Gaskets For Pem Fuel Cells, Robert Lazarin
Open Access Theses & Dissertations
The purpose of this thesis is to study the feasibility of low-cost additive manufacturing of gaskets for proton exchange membrane fuel cells exposed to extreme temperature conditions ranging from -55°C to 100°C. With the growing popularity and decreasing costs of additive manufacturing technologies, specifically Material Extrusion (ME), research is being conducted to determine the feasibility of ME components. Thermally cycled PEMFCs may exhibit accelerated gasket deterioration, therefore, the mechanical stability of material extruded gaskets following a harsh thermal cycle must be assessed. The feasibility of the material extruded gaskets will be proven by manufacturing optimization and mechanical testing. The target …
Magnetic Structures Of Sawtooth Olivines Mn2six 4 (X = S, Se) Determined Through Neutron Powder Diffraction, Melaku Sisay Tafere
Magnetic Structures Of Sawtooth Olivines Mn2six 4 (X = S, Se) Determined Through Neutron Powder Diffraction, Melaku Sisay Tafere
Open Access Theses & Dissertations
In olivine chalcogenide Mn2SiX 4 (X = S, Se) compounds, the Mn lattice produces a sawtooth, which is of critical significance in magnetism due to the potential for manifesting at bands in the magnon spectrum, a crucial component in magnonics. The compounds Mn2SiS4 and Mn2SiSe4 in Mn2SiX 4 family undergo antiferromagnetic phase transitions at T â?? 85 K and â?? 66 K, respectively, as determined from the specific heat, Cp(T). The average and local crystal structuresare determined using synchrotron X-ray, neutron diffraction, and X-ray total scattering data followed by Rietveld and pair distribution function (PDF) analysis. It is found from …
Fabrication, Microstructure And Mechanical Characterization Of Crvnbtaw High Entropy Alloy Coatings Using Magnetron Sputtering, Jorge Quezada
Fabrication, Microstructure And Mechanical Characterization Of Crvnbtaw High Entropy Alloy Coatings Using Magnetron Sputtering, Jorge Quezada
Open Access Theses & Dissertations
In this project a CrVNbTaW high entropy alloy was evaluated. The samples were made using radio frequency magnetron sputtering and were made under similar conditions. The deposition parameters were explored to find the ideal deposition process. The process included a pressure from 0.1-2mTorr, 600C, 1 hour duration, at 100W power to guns, and constant argon flow. The samples were fabricated under similar parameters using silicon steel and sapphire substrates. The samples were analyzed and characterized using X-ray diffraction, scanning electron microscopy, atomic force microscopy, nanoindentation and corrosion testing. Based on these results we were able to get a better understanding …
A Comparative Evaluation Of Oxidation And Combustion Phenomena In Ti-6al-4v Exposed To Earth Re-Entry And Arc-Jet Test Environments, Arlene Smith
Open Access Theses & Dissertations
The Ti-6Al-4V alloy is widely used in aerospace applications for its beneficial combination of properties. However, this alloy has high solubility for oxygen and thus a high reactivity. Recovered data contained within the Columbia artifacts suggests that this alloy underwent an accelerated degradation and combustion reaction when exposed to the high enthalpy, low-pressure surroundings experienced during reentry into Earth's atmosphere. Arc-jet testing has provided a simulated aerothermodynamic heating environment to mimic what the spacecraft endured. When the effect of thermal alteration on this alpha-beta phase alloy was investigated during previous studies, optical metallography and microhardness tests revealed inconsistencies between samples …
Novel Interlaminar Reinforcement To Enhance The Impact Damage Resistance Of Carbon Fiber-Reinforced Polymer Matrix Composites, Daisy Haidee Mariscal
Novel Interlaminar Reinforcement To Enhance The Impact Damage Resistance Of Carbon Fiber-Reinforced Polymer Matrix Composites, Daisy Haidee Mariscal
Open Access Theses & Dissertations
Aerospace, aircraft, marine, and automobile applications are increasingly using composite materials for lighter, higher stiffness, and strength properties. Despite these advantages, composite materials have one major disadvantage. The through-thickness properties are extremely weak when subjected to impact damage. When a composite material is subjected to a low-velocity impact, there is hardly any visible damage on the surface compromising the composite material internally without any external notice. Internal damage may be delamination, which is the most common, matrix cracking, and fiber breakage. A composite material is made up of layers of fiber. The interlaminar region is located in between these layers. …
Laser Powder Bed Fusion Process, Structure, And Properties: Holistic Approach To Establishing Metallurgical Quality, Hunter Taylor
Laser Powder Bed Fusion Process, Structure, And Properties: Holistic Approach To Establishing Metallurgical Quality, Hunter Taylor
Open Access Theses & Dissertations
The advent of metal additive manufacturing (AM) was posed as a disruption to casting, forging, machining, and forming with the notion "complexity is free". However, since invention in the late 1990's the marketed potential has not been realized. Metal based AM is best viewed from the process-structure-properties-performance (PSPP) paradigm taught in material science and engineering, which links the process history to the part performance. Understanding the complex and localized process control made available by AM creates a significant challenge in defining the materials structure, properties, and performance. The lack of holistic understating of inputs and corresponding results has been identified …
Using Ultrasonication For The Improvement Of Grade And Recovery In Molybdenum Sulfide Flotation, Wayne Alexander Campbell
Using Ultrasonication For The Improvement Of Grade And Recovery In Molybdenum Sulfide Flotation, Wayne Alexander Campbell
Open Access Theses & Dissertations
Experimentation was performed on molybdenite slurry by using ultrasonication to elucidate the effects of ultrasonic-induced bubble cavitation on the grade, recovery, and gangue reduction during small-scale flotation tests and was followed by a topographical analysis of quartz particles using SEM. Ultrasonic waves at 20-80 kHz that propagate through a liquid medium cause microbubbles to form, grow, and implode. The cavitation bubble's implosion causes brief extreme local conditions where temperatures can reach 5,000 K and pressures of 1,000 bar. The resulting microjets create mechanical and chemical changes to the system and were directed at improving flotation dynamics in these experiments. Through …
Characterization Of 3d Stereolithography (Sla) Printed Polymer For Autonomous-Flow Microfluidic Devices, Michelle Gamboa
Characterization Of 3d Stereolithography (Sla) Printed Polymer For Autonomous-Flow Microfluidic Devices, Michelle Gamboa
Open Access Theses & Dissertations
3D Stereolithography (SLA) printing is a high-throughput, precise and reproducible manufacturing platform which makes it a desirable technique to develop microfluidic devices for bioanalytical applications. However, limited information exists regarding the physical, chemical, and biological properties of the polymer resins used in 3D SLA printing. This project demonstrates the characterization of a commercially available 3D SLA printed resin polymer used to develop an autonomous-flow (self-driven) microfluidic device. In this investigation, time-dependent materials characterization was done on the Formlabs clear V4 resin to observe changes in mechanical and surface properties. The clear, printed polymer was analyzed with attenuated total reflectance (ATR), …
Pressure-Induced Phase Transition And Electronic Structure Changes In Equiatomic Fev, Homero Reyes Pulido
Pressure-Induced Phase Transition And Electronic Structure Changes In Equiatomic Fev, Homero Reyes Pulido
Open Access Theses & Dissertations
Classical molecular dynamics methods can accurately describe a broad set of many-atomssystems. Although more economical, the results given by this framework lack the precision capable of density functional theory (DFT). Therefore, the structural stability of the B2 phase of a body-centered-cubic iron-vanadium (FeV) alloy using DFT on the electronic structure level is analyzed to verify and further explain classical results obtained by our group in this same alloy. Using Quantum Espresso and Phonopy for the computational simulations, the plotted band structure, electronic density of states (eDOS), phonon dispersions, charge density, and Fermi surfaces for various compressed unit cells are presented. …
Reflectance Spectral Characterization And Taxonomy Applications Of Spacecraft Materials To Aid Space Situational Awareness, Jacqueline Andrea Reyes
Reflectance Spectral Characterization And Taxonomy Applications Of Spacecraft Materials To Aid Space Situational Awareness, Jacqueline Andrea Reyes
Open Access Theses & Dissertations
The increasing number of space missions involving successfully deployed spacecraft have resulted in an augmented density of artificial objects positioned in orbital domains near Earth. With this steady accumulation of objects in space, it has become increasingly imperative to characterize spacecraft materials, which may ultimately be contributors to the orbital debris population. In an effort to identify unique material-specific spectroscopic markers, a variety of spacecraft materials frequently utilized in the aerospace industry to construct typical spacecraft were analyzed using reflectance spectroscopy as a characterization technique for assessment on material type according to optical features. This is significant in providing information …
Rational Design Of Composite Nanomaterials For Water Treatment Applications, Mariana Marcos-Hernandez
Rational Design Of Composite Nanomaterials For Water Treatment Applications, Mariana Marcos-Hernandez
Open Access Theses & Dissertations
Water quantity and quality have been affected in communities all around the world due to population growth, pollution, changes in land use, and climate change. In order to cope with existing and anticipated water demands and shortages, the use of treated or reclaimed water is an ongoing alternative that has helped communities all over the world address this problem. The adaptation of nanotechnology to traditional water and wastewater treatment processes offers new opportunities in technological developments. Unique size-dependent properties such as: high surface to mass ratio, high reactivity, high sorption capacities, fast dissolution, superparamagnetism, among others, provide high-tech efficient materials …