A Comprehensive Reliability-Based Framework For Corrosion Damage Monitoring And Repair Design Of Reinforced Concrete Structures,
2018
Texas A&M University
A Comprehensive Reliability-Based Framework For Corrosion Damage Monitoring And Repair Design Of Reinforced Concrete Structures, Homero Castaneda, Aydin Karsilaya, Ayman Okeil, Mahmoud Reda Taha
Publications
In this work, we developed a comprehensive framework for corrosion management of reinforced concrete (RC) structures. This framework includes critical steps of an effective approach to quantify the damage evolution as well as providing the timeframe for effective maintenance/repair strategies for corrosion assessment in RC structures. The framework included several activities including the use of indirect and direct inspection tools, theoretical development for damage prediction, experimental measurements and theoretical development of repair time based on reliability. The uniqueness of the framework is the integration of deterministic modeling of corrosion damage evolution by using mechanistic analysis with statistical modeling on corrosion …
Evaluation Of Comparative Damaging Effects Of Multiple Truck Axles For Flexible Pavements,
2018
University of Texas at Arlington
Evaluation Of Comparative Damaging Effects Of Multiple Truck Axles For Flexible Pavements, Stefan Romanoschi, Athanassios Papagiannakis
Publications
This study aims at evaluating the effect of overlapping flexible pavement strain responses from truck axles that are not part of multiple axle configurations (i.e., tandem, triple and quad). For this purpose, a newly constructed pavement was instrumented with strain gauges installed at the bottom of the asphalt concrete base layer on US-287 south of Mansfield, TX. This pavement structure is typically used for medium- to high-volume roads in the South-Central region of the United States. The strain gauges were used to measure longitudinal and transverse strains under several passes of a test vehicle. This was a class 6 truck …
Characterization Of Nanomaterials For Thermal Management Of Electronics,
2018
Louisiana Tech University
Characterization Of Nanomaterials For Thermal Management Of Electronics, Amit Rai
Doctoral Dissertations
Recently, there has been a growing interest in flexible electronic devices as they are light, highly flexible, robust, and use less expensive substrate materials. Such devices are affected by thermal management issues that can reduce the device’s performance and reliability. Therefore, this work is focused on the study of the thermal properties of nanomaterials and the methods to address such issues. The goal is to enhance the effective thermal conductivity by adding nanomaterials to the polymer matrix or by structural modification of nanomaterials. The thermal conductivity of copper nanowire/polydimethylsiloxane and copper nanowire/polyurethane composites were measured and showed more than threefold …
Metal Segregation During The Solidification Of Titanium-Aluminum Alloys For 3d Printing Applications,
2018
Louisiana Tech University
Metal Segregation During The Solidification Of Titanium-Aluminum Alloys For 3d Printing Applications, Jwala Parajuli
Master's Theses
Titanium-Aluminum alloys are one of the widely used alloys in multiple engineering applications. They are highly preferred in Selective Laser Melting (SLM) processes due to their low density, high melting temperature, and good strength. Segregation occurs during the solidification of most alloys and produces a non-uniform distribution of atoms. In SLM, segregation may depict the type of adhesion between the two deposited interfacial layers and the strength between the interphase between an already solidified layer and a new one, and overall, the quality of the printed part. In order to avoid segregation, the understanding of the segregation behavior at atomistic …
Nanoparticle Catalytic Enhancement Of Carbon Dioxide Reforming Of Methane For Hydrogen Production,
2018
Louisiana Tech University
Nanoparticle Catalytic Enhancement Of Carbon Dioxide Reforming Of Methane For Hydrogen Production, Nicholas Groden
Doctoral Dissertations
The U.S. produces 5559.6 million metric tons of carbon dioxide annually, of which 21% is produced by industrial processes. Steam reforming, an industrial process that accounts for 95% of all hydrogen production in industry, produces 134.5 million metric tons of carbon dioxide or around 11% of the total carbon dioxide produced by industry. This carbon dioxide is then either emitted or goes through a sequestration process that accounts for 75% of the plant's operational costs. An alternative reaction to steam reforming is dry reforming, which utilizes carbon dioxide rather than emitting it and can be used in conjunction with current …
Electrical Characterization Of Graphene And Nanodiamond Nanostructures,
2018
Louisiana Tech University
Electrical Characterization Of Graphene And Nanodiamond Nanostructures, A Z M Nowzesh Hasan
Doctoral Dissertations
The electrical characterization on two-dimensional carbon-based graphene and nanodiamond materials was performed to improve charge transport properties for the label-free electrical biosensors. The charge transport in solution-gated graphene devices is affected by the impurities and disorders of the underlying dielectric interface and its interaction with the electrolytes. Advancement in field-effect ion sensing by introducing a dielectric isomorph, hexagonal boron nitride between graphene and silicon dioxide of a solution-gated graphene field-effect transistor was investigated. Increased transconductance due to increased charge carrier mobility is accompanied with larger ionic sensitivity. These findings define a standard to construct future graphene devices for biosensing and …
Effective Magnetic And Electric Response Of Composite Materials,
2018
Louisiana Tech University
Effective Magnetic And Electric Response Of Composite Materials, Mona Hassan Alsaleh
Doctoral Dissertations
Metamaterials (MMs) are nanocomposite materials consisting of metal-dielectric resonators much smaller in size than the wavelength of the incident light. Common examples of metamaterials are based on split ring resonators (SRRs), parallel wires or strips and fishnet structures. These types of materials are designed and fabricated in order to provide unique optical responses to the incident electromagnetic radiation that are not available in naturally existing materials. The MMs can exhibit unusual properties such as strong magnetism at terahertz (THz) and optical frequencies. Additionally, negative index materials (NIMs) can provide negative index of refraction which can be used in many applications …
Achieving High Catalytic Activity And Redox Stability Of Doped Ceria Through A Novel Sol Gel Synthesis,
2018
University of New Mexico
Achieving High Catalytic Activity And Redox Stability Of Doped Ceria Through A Novel Sol Gel Synthesis, Christopher Riley
Shared Knowledge Conference
Ceria is widely studied in catalysis because of its high oxygen mobility and storage capacity. These properties are enhanced by the incorporation of dopant atoms into the ceria crystal structure. However, creating a homogenously doped structure requires a suitable synthesis technique. Otherwise, dopant atoms form an oxide phase on the ceria surface, which blocks highly active catalytic sites. Traditional production methods allow for cerium and dopant ions to segregate during synthesis. In this work, we demonstrate a novel sol gel synthesis method for producing homogeneously doped ceria. The method is easy and avoids the use of hazardous chemicals. Higher dopant …
Self-Healing Microcapsules As Concrete Aggregates For Corrosion Inhibition In Reinforced Concrete,
2018
Texas A&M University
Self-Healing Microcapsules As Concrete Aggregates For Corrosion Inhibition In Reinforced Concrete, Homero Castaneda, Marwa Hassan, Miladin Radovic, Jose Milla
Publications
Reinforced Concrete (RC) structures are vital to the US’s civil infrastructure for their strength and versatility. Unfortunately, RC elements deteriorate rapidly when exposed to corrosive environments. One possible solution is to extend the life of RC elements and systems using microencapsulated corrosion inhibitors to reduce the rebar corrosion rate. The capsules house an anodic corrosion inhibitor agent including calcium nitrate (CN) and triethanolamine (TEA). The integration of such microencapsulated materials will enhance the durability and extend the useful life by controlling the corrosion precursors and the corrosion process during damage evolution. Therefore, this work aims to develop and characterize the …
Magnetoelectric Memory Cells With Domain-Wall-Mediated Switching,
2018
University of Nebraska - Lincoln
Magnetoelectric Memory Cells With Domain-Wall-Mediated Switching, Kirill Belashchenko, Oleg Tchernyshyov, Alexey Kovalev, Dmitri Nikonov
Kirill Belashchenko Publications
A magnetoelectric memory cell with domain - wall - mediated switching is implemented using a split gate architecture . The split gate architecture allows a domain wall to be trapped within a magnetoelectric antiferromagnetic ( MEAF ) active layer . An extension of this architecture applies to multiple gate linear arrays that can offer advantages in memory density , programmability , and logic functionality . Applying a small anisotropic in - plane shear strain to the MEAF can block domain wall precession to improve reliability and speed of switching
Impacts Of Moisture On Asphalt Properties,
2018
Arkansas State University
Impacts Of Moisture On Asphalt Properties, Zahid Hossain
Publications
Stripping related moisture damage has been recognized as one of the major pavement distresses since the early 1990s. The main objective of this study is to establish an effective test protocol to quantify moisture susceptibility of asphalt pavements. To this end, selective test methods (Texas Boiling test, Tensile Strength Ratio, Retained Stability, and Hamburg Wheel Test), and procedures based on surface chemistries and molecular-level mechanistic properties have been investigated in this study. Firstly, a comprehensive list of literature related to moisture damage in asphalts was reviewed. Based on the literature review, a detailed project plan and test matrix were developed. …
Development Of A Simple Lab-Scale Vacuum Assisted Resin Transfer Molding (Vartm) Process,
2018
University of Dayton
Development Of A Simple Lab-Scale Vacuum Assisted Resin Transfer Molding (Vartm) Process, Donald A. Klosterman
Chemical and Materials Engineering Faculty Publications
The goal of the current study was to develop and demonstrate a simple and quick lab-scale VARTM process for the purpose of making flat panels for subsequent characterization, for example in new materials development efforts. This process was not intended to be optimized for final production, rather it served as the quickest way to make lab-scale composite panels using VARTM while maintaining all the salient features of typical VARTM processes used in larger scale manufacturing. There is a wide variety of ways to implement VARTM, as well as a diverse list of potential materials and supplies from which to choose. …
Enhancing The Durability And The Service Life Of Asphalt Pavements Through Innovative Light-Induced Self-Healing Materials,
2018
Louisiana State University
Enhancing The Durability And The Service Life Of Asphalt Pavements Through Innovative Light-Induced Self-Healing Materials, Marwa Hassan
Publications
The objective of this study was to evaluate the efficiency of a new generation of Ultraviolet (UV) light-induced selfhealing polymers in enhancing the durability and self-healing properties of asphalt mixtures. Self-healing polymers were successfully synthesized in the laboratory and were characterized using Fourier Transform Infrared Spectroscopy (FTIR). In addition, Thermogravimetric Analysis (TGA) results showed that the synthesized polymers achieved the required thermal stability to resist asphalt mixture production processes. Viscosity results showed that addition of 5% Recycled Asphalt Shingle (RAS) and/or 20% Reclaimed Asphalt Pavement (RAP) caused an increase in the viscosity of the binder blends. However, a reduction in …
Evaluation Of The Performance And Cost-Effectiveness Of Engineered Cementitious Composites (Ecc) Produced From Region 6 Local Materials,
2018
Louisiana State University
Evaluation Of The Performance And Cost-Effectiveness Of Engineered Cementitious Composites (Ecc) Produced From Region 6 Local Materials, Gabriel Andres Arce Amador, Tyson Rupnow, Marwa Hassan
Publications
The project objective is to develop cost-effective Engineered Cementitious Composites (ECC) with locally available ingredients in Region 6 to address the deficiencies observed in ordinary concrete materials. The study explored the utilization of two types of river sands (coarse and fine), two types of PVA fibers (long and short), four levels of cement replacement with Class F fly ash, and the implementation of recycled crumb rubber in the performance of ECC materials. A total of 24 mix designs were prepared and evaluated in compression, tension, and bending to assess its mechanical properties. Furthermore, the cracking characteristics of the materials produced …
Use Of Rice Hull Ash (Rha) As A Sustainable Source Of Construction Material,
2018
Arkansas State University
Use Of Rice Hull Ash (Rha) As A Sustainable Source Of Construction Material, Zahid Hossain, Ashraf Elsayed
Publications
With the imminent shortage of natural resources, the need to find sustainable development is the highest in recent history. Therefore, this study examines the potential uses of Rice Hull Ash (RHA) as a sustainable cementitious material (SCM) in preparation of concrete. This study also assesses the use of RHA as an alternative of commonly used polymers in preparing high-grade asphalt binders. RHA is a potential sustainable solution because it is currently being treated as an agricultural waste material, yet its high silica content makes it a potential construction material. Three different sizes of RHA (600 µm, 150 µm, and 44 …
Use Of Nanoclays As Alternatives Of Polymers Toward Improving Performance Of Asphalt Binders,
2018
Arkansas State University
Use Of Nanoclays As Alternatives Of Polymers Toward Improving Performance Of Asphalt Binders, Zahid Hossain, Ashraf Elsayed
Publications
The main goal of this study is to assess the feasibility of the use of nanoclay as an alternative to commonly used polymers such as styrene-butadiene-styrene (SBS), which are used to modify the performance grade (PG) of asphalt binders. Three types of nanoclay and two types of neat binders were selected for laboratory investigation. Different amounts (1, 2, and 3%) of nanoclays were used. A blending protocol has been developed to mix the nanoclay with the asphalt binder. Rotational Viscosity (RV), Dynamic Shear Rheometer (DSR), Optical Contact Analyzer (OCA) and Atomic Force Microscope (AFM) were conducted to evaluate the properties …
Development Of A Self-Healing And Rejuvenating Mechanisms For Asphalt Mixtures Containing Recycled Asphalt Shingle,
2018
Louisiana State University
Development Of A Self-Healing And Rejuvenating Mechanisms For Asphalt Mixtures Containing Recycled Asphalt Shingle, Marwa Hassan
Publications
The objective of this study was to test the hypothesis that hollow-fibers encapsulating a rejuvenator product could improve both self-healing, rejuvenation, and mechanical properties of asphalt mixtures. Hollow-fibers containing a rejuvenating product were synthesized via a wet spinning procedure with sodium-alginate polymer as the encapsulating material. An optimization of the production parameters for the synthesis of fibers was performed to develop fibers suitable for high-temperature and shear stress environment typical of asphalt mixture production. A self-healing experiment was conducted to evaluate the healing/rejuvenation capabilities of sodium-alginate fibers in asphalt mixtures with varying types of binders and recycled materials. Based on …
Development Of A Standard Test Method For Characterization Of Asphalt Materials And Aging-Related Degradation Using An Extensional Rheometer,
2018
Louisiana Tech University
Development Of A Standard Test Method For Characterization Of Asphalt Materials And Aging-Related Degradation Using An Extensional Rheometer, Nazimuddin Wasiuddin
Publications
An extensional deformation test method using a Sentmanat Extensional Rheometer (SER) fixture inside a Dynamic Shear Rheometer (DSR) is developed in this study to investigate the degradation of the polymer due to aging and to investigate the effect of modifier type. A relationship between different percentages of modifier and ductility of the modified binder is also investigated. The sample geometrics used in this study are 1 mm x 0.72 mm and 3 mm x 0.72 mm. A total of one hundred and sixty-two samples were tested. Three modifiers Styrene-Butadiene-Styrene (SBS), Polyphosphoric Acid (PPA) and latex were used. One PG 76-22, …
Bridge Deck Overlays Using Ultra-High Performance Concrete,
2018
New Mexico State University
Bridge Deck Overlays Using Ultra-High Performance Concrete, Craig Newtson, Brad Weldon
Publications
This study investigated the use of a locally produced ultra-high performance concrete (UHPC) as an alternative to typical overlay materials. Several bond strength tests including slant-shear, splitting tension, and direct tension tests were performed to assess the bond strength between UHPC and normal strength concrete (NSC) substrate with varying surface textures. Tests were also conducted to assess the early-age and longer-term shrinkage behavior and coefficient of thermal expansion of the UHPC as well as rapid chloride permeability testing. Good bond between UHPC and NSC substrate was observed even with inadequate surface texture. Combined shrinkage and thermal effects were investigated for …
Experimental Tests And Numerical Simulations For Failure Investigation On Corrugated Boxes Used On Household Appliance Packaging,
2018
Whirlpool Latin America
Experimental Tests And Numerical Simulations For Failure Investigation On Corrugated Boxes Used On Household Appliance Packaging, Diego Fernandes Rodrigues, José Carlos Pereira
Journal of Applied Packaging Research
Packages made of corrugated paper are fundamental to the protection, transportation and handling of the appliance product market. During the storage and sales stages of a product, the package must resist compressive loads in different directions beyond moderate impacts. In this context, the objective of this work is to develop and implement a post-processor that allows the simultaneous analysis of two of the most common failure modes of packages made of corrugated paper: failure due to tensile or compressive stress limit, and failure due to local buckling, when the buckling of the faces of the corrugated paper between two peaks …
