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Full-Text Articles in Engineering

Impact Of Chain Architecture On The Thickness Dependence Of Physical Aging Rate Of Thin Polystyrene Films, Gregory Brown, Elizabeth Lewis, Bryan D. Vogt Jan 2020

Impact Of Chain Architecture On The Thickness Dependence Of Physical Aging Rate Of Thin Polystyrene Films, Gregory Brown, Elizabeth Lewis, Bryan D. Vogt

Honors Research Projects

The dynamics of polymer thin films have been demonstrated to be significantly altered from the bulk, but the origins of such differences are not well defined. In this work, we seek to understand the differences in the structural dynamics (or physical aging) of polystyrene (PS) through branching and other well defined architectures (comb and centipede). The aging dynamics of ultrathin films (< 30 nm) differ from relatively thick films (100-150nm) with linear PS thin films aging more rapidly than the relatively “bulk-like” thick films. Ellipsometric measurements are used to characterize the physical aging rate of the films. The change in film thickness and refractive index as the films are held below the glass transition temperature (Tg) provides a simple measure of the physical aging. In this study, four different architectures (linear, comb, 4 arm star, and centipede) will be investigated. For each PS architecture, the aging rate will be determined for film thickness ranging ...


Slip Of Shuffle Screw Dislocations Through Tilt Grain Boundaries In Silicon, Hao Chen, Valery Levitas, Liming Xiong Feb 2019

Slip Of Shuffle Screw Dislocations Through Tilt Grain Boundaries In Silicon, Hao Chen, Valery Levitas, Liming Xiong

Aerospace Engineering Publications

In this paper, molecular dynamics (MD) simulations of the interaction between tilt grain boundaries (GBs) and a shuffle screw dislocation in silicon are performed. Results show that dislocations transmit into the neighboring grain for all GBs in silicon. For Σ3, Σ9 and Σ19 GBs, when a dislocation interacts with a heptagon site, it transmits the GB directly. In contrast, when interacting with a pentagon site, it first cross slips to a plane on the heptagon site and then transmits the GB. The energy barrier is also quantified using the climbing image nudged elastic band (CINEB) method. Results show that Σ3 ...


Economic Potential For Distributed Manufacturing Of Adaptive Aids For Arthritis Patients N The U.S., Nicole Gallup, Jennifer Bow, Joshua M. Pearce Dec 2018

Economic Potential For Distributed Manufacturing Of Adaptive Aids For Arthritis Patients N The U.S., Nicole Gallup, Jennifer Bow, Joshua M. Pearce

Department of Materials Science and Engineering Publications

By 2040, more than a quarter of the U.S. population will have diagnosed arthritic conditions. Adults with arthritis and other rheumatic conditions earn less than average yet have medical care expenditures that are over 12% of average household income. Adaptive aids can help arthritis patients continue to maintain independence and quality of life; however, their high costs limit accessibility for older people and the poor. One method used for consumer price reduction is distributed manufacturing with 3-D printers. In order to assess if such a method would be financially beneficial, this study evaluates the techno-economic viability of distributed manufacturing ...


Young’S Modulus As A Measurement To Estimate Damage Related With Alkali-Silica Reaction In Concrete., Anazaria J. Ortega Gonzalez Dec 2018

Young’S Modulus As A Measurement To Estimate Damage Related With Alkali-Silica Reaction In Concrete., Anazaria J. Ortega Gonzalez

Civil Engineering Undergraduate Honors Theses

The main purpose of this research is to compare two nondestructive methods to assess Alkali-Silica reaction (ASR) in concrete. Fifteen concrete prisms were cast using aggregates with different Alkali-Silica reactivity such as Jobe sand and Van Buren sand. The change in strain, shear wave velocity and Young’s modulus were determined according to ASTM C129 and ASTM C215, respectively. This data was collected by Dillon K Self, who determined that the shear wave velocity and strain are inversely proportional. However, when single cracking in the concrete specimen transition to map cracking, the shear wave velocity dropped significantly, whereas the strain ...


Mechanical Characterization Of Expanded Polystyrene Spheres Embed Sandwich Composites For Packaging Applications, Maheswaran R, Arockia Reemas S Nov 2018

Mechanical Characterization Of Expanded Polystyrene Spheres Embed Sandwich Composites For Packaging Applications, Maheswaran R, Arockia Reemas S

Journal of Applied Packaging Research

This paper addresses on study of development of new packaging material comprising Expanded Polystyrene Spheres (EPS) embedded epoxy polymer based sandwich composites with aluminium skin. The density of the packing material is controlled by varying the volume of embedded spheres. In this study, the Flexural and Compression performance of Expanded Polystyrene Spheres (EPS) embedded polymer based sandwich composites with aluminium skin are investigated. The EPS volume percent in the core is 25% with epoxy matrix which makes the the density less than 1 g/cm3 for the composite. The fabricated Sandwich Composite are very light weight, the density is less ...


Cementitious Sensors Exhibiting Stopbands In Acoustic Transmission Spectra, Shreya Vemuganti Nov 2018

Cementitious Sensors Exhibiting Stopbands In Acoustic Transmission Spectra, Shreya Vemuganti

Shared Knowledge Conference

Ultrasonic monitoring in cementitious materials is challenging due to the high degree of attenuation. In wellbore environments, monitoring becomes more challenging due to inaccessibility. Meta materials, also known as acoustic bandgap materials, exhibit an interesting feature of forbidding the propagation of elastic/sound waves and isolate vibration in a certain frequency band. Traditionally, acoustic bandgap materials are developed with inclusions such as tin, aluminum, gold, steel in a polymer matrix. In this study, we present the development of three-dimensional cementitious sensors capable of exhibiting stopbands in the acoustic transmission spectra using carbon nanotubes. Relatively wide stopbands were engineered using Floquet-Bloch ...


Achieving High Catalytic Activity And Redox Stability Of Doped Ceria Through A Novel Sol Gel Synthesis, Christopher Riley Nov 2018

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 ...


Controlled Nanomorphology Of Hybrid Organic/Inorganic Multi-Component Composites Through Cooperative Non-Covalent Interactions, Lingyao Meng Nov 2018

Controlled Nanomorphology Of Hybrid Organic/Inorganic Multi-Component Composites Through Cooperative Non-Covalent Interactions, Lingyao Meng

Shared Knowledge Conference

Hybrid organic–inorganic nanocomposite polymers, with inorganic nanoparticles embedded in organic matrix have emerged as a special category of multifunctional materials. With rational materials design, these hybrids can show the synergistic effect of the properties from both phases. Homogenous dispersion and orderly arrangement of the organic and inorganic components are key in their functionalities. By controlling the interface and corresponding interfacial interactions between the organic and inorganic entities, we have developed a logical approach to form stable and controlled hybrid nanofiber structures. We demonstrate the formation of hybrid polymer/quantum dots (or iron oxide nanoparticles) nanocomposites through non-covalent interactions (hydrogen ...


A Systematic Investigation Of Condensation Heat Transfer Using Microscale Asymmetric Surfaces, Emily Brown Nov 2018

A Systematic Investigation Of Condensation Heat Transfer Using Microscale Asymmetric Surfaces, Emily Brown

LSU Master's Theses

Asymmetric surfaces been shown to inducing unidirectional motion in the Leidenfrost regime; however, very minimal research has been conducted to investigate whether these surface can enhance condensation through the same means. The investigation of heat transfer of ratchets in condensation is a relatively untapped area of study, specifically ratchets with superhydrophobic properties. Anticipated difficulty lies in creating surfaces features or coatings that retain the ratchets and can adequately sustain optimal wetting state of Cassie-Baxter required to improve heat transfer performance during condensation. This study serves to investigate whether ratchets are a feasible surface feature to enhance condensation heat transfer. First ...


Electrically-Conductive Asphalt Mastic: Temperature Dependence And Heating Efficiency, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Alireza Sassani, Kasthurirangan Gopalakrishnan, Mani Mina Nov 2018

Electrically-Conductive Asphalt Mastic: Temperature Dependence And Heating Efficiency, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Alireza Sassani, Kasthurirangan Gopalakrishnan, Mani Mina

Civil, Construction and Environmental Engineering Publications

Asphalt mastic, a pitch-matrix composite, consists of bitumen and mineral fillers (very fine aggregates), that fills the voids created by coarser aggregates in asphalt concrete. In this study, asphalt mastic was modified with carbon fiber (CF) and graphite powder (GP) to produce single-phase (containing only CF) and two-phase (containing both CF and GP) electrically-conductive asphalt mastic (ECAM) for anti-icing and deicing applications. Volume resistivities of ECAMs were measured at two different temperatures and the influence of temperature on electrical conductivity was evaluated, revealing that reduction in temperature enhances the ECAM's electrical conductivity. After analyzing the volume resistivity data for ...


Thermal Transport Study On Actinide Oxides Using Phonon Density Of States Calculation, Alex Resnick, Katherine Mitchell Nov 2018

Thermal Transport Study On Actinide Oxides Using Phonon Density Of States Calculation, Alex Resnick, Katherine Mitchell

Georgia Undergraduate Research Conference (GURC)

The thermophysical properties of nuclear fuels being developed in generation IV nuclear reactors are still being widely examined since the reactor’s operating performance is strongly correlated to the thermal transport properties of the fuel source. In this research, phonon density of states (DOS) are estimated for uranium dioxide (UO2), thorium dioxide (ThO2), and plutonium dioxide (PuO2) as these are all significant representations of the actinide oxide family. The crystalline structures of these fuels are altered to contain point defects in the form of primary atom vacancies, oxygen vacancies, and uranium substitution. Primary atom and oxygen vacancies ...


Self-Healing Microcapsules As Concrete Aggregates For Corrosion Inhibition In Reinforced Concrete, Homero Castaneda, Marwa Hassan, Miladin Radovic, Jose Milla Nov 2018

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 ...


Lanthanide Ions Doped In Vanadium Oxide For Sensitive Optical Glucose Detection, Ansam J. Talib, Masfer Alkahtani, Linkun Jiang, Fahad Alghannam, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Alexei V. Sokolov, Philip R. Hemmer Nov 2018

Lanthanide Ions Doped In Vanadium Oxide For Sensitive Optical Glucose Detection, Ansam J. Talib, Masfer Alkahtani, Linkun Jiang, Fahad Alghannam, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Alexei V. Sokolov, Philip R. Hemmer

Mechanical Engineering Publications

Blood glucose monitoring is essential to avoid the unwanted consequences of glucose level fluctuations. Optical monitors are of special interest because they can be non-invasive. Among optical glucose sensors, fluorescent upconversion nanoparticles (UCNPs) have the advantage of good photostability, low toxicity, and exceptional autofluorescence suppression. However, to sense glucose, UCNPs normally need surface functionalization, and this can be easily affected by other factors in biological systems, and may also affect their ability for real-time sensing of both increasing and decreasing glucose levels. Here, we report YVO4 : Yb3+, Er3+@Nd3+core/shell UCNPs with Nd and Yb shell and GdVO4 : Yb3 ...


Micronutrient Availability In Alternative Foods During Agricultural Catastrophes, David C. Denkenberger, Joshua M. Pearce Oct 2018

Micronutrient Availability In Alternative Foods During Agricultural Catastrophes, David C. Denkenberger, Joshua M. Pearce

Department of Materials Science and Engineering Publications

Several catastrophes could block the sun, including asteroid/comet impact, super volcanic eruption, and nuclear war with the burning of cities (nuclear winter). Previous work has analyzed alternate food supplies (e.g., mushrooms growing on dead trees, bacteria growing on natural gas). This was shown to be technically capable of feeding everyone with macronutrients (protein, carbohydrates, and lipids) and minerals, although economics and politics remain uncertain. The present work analyzes vitamin availability in such alternative food scenarios. The vitamin content of various alternate foods is compared to the US recommended daily allowance (RDA) as well as the average requirement defined ...


Corrosion Resistance Of Pipeline Steel With Damaged Enamel Coating And Cathodic Protection, Liang Fan, Signo Tadeu Dos Reis, Genda Chen, Michael L. Koenigstein Oct 2018

Corrosion Resistance Of Pipeline Steel With Damaged Enamel Coating And Cathodic Protection, Liang Fan, Signo Tadeu Dos Reis, Genda Chen, Michael L. Koenigstein

Genda Chen

This paper presents the first report on the corrosion resistance of pipeline steel with damaged enamel coating and cathodic protection in 3.5 wt % NaCl solution. In particular, dual cells are set up to separate the solution in contact with the damaged and intact enamel coating areas, to produce a local corrosion resistance measurement for the first time. Enamel-coated steel samples, with two levels of cathodic protection, are tested to investigate their impedance by electrochemical impedance spectroscopy (EIS) and their cathodic current demand by a potentiostatic test. Due to its glass transition temperature, the enamel-coated pipeline can be operated on ...


Lattice Instability During Solid-Solid Structural Transformations Under A General Applied Stress Tensor: Example Of Si I → Si Ii With Metallization, Nikolai A. Zarkevich, Hao Chen, Valery I. Levitas, Duane D. Johnson Oct 2018

Lattice Instability During Solid-Solid Structural Transformations Under A General Applied Stress Tensor: Example Of Si I → Si Ii With Metallization, Nikolai A. Zarkevich, Hao Chen, Valery I. Levitas, Duane D. Johnson

Aerospace Engineering Publications

The density functional theory was employed to study the stress-strain behavior and elastic instabilities during the solid-solid phase transformation (PT) when subjected to a general stress tensor, as exemplified for semiconducting Si I and metallic Si II, where metallization precedes the PT, so stressed Si I can be a metal. The hydrostatic PT occurs at 76 GPa, while under uniaxial loading it is 11 GPa (3.7 GPa mean pressure), 21 times lower. The Si I → Si II PT is described by a critical value of the phase-field’s modified transformation work, and the PT criterion has only two parameters ...


Three-Dimensional Forming Of Multi-Layered Materials: Material Heat Response And Quality Aspects, Sami-Seppo Ovaska, Pavel Geydt, Ville Leminen, Johanna Lyytikäinen, Sami Matthews, Panu Tanninen, Malte Wallmeier, Marek Hauptmann, Kaj Backfolk Oct 2018

Three-Dimensional Forming Of Multi-Layered Materials: Material Heat Response And Quality Aspects, Sami-Seppo Ovaska, Pavel Geydt, Ville Leminen, Johanna Lyytikäinen, Sami Matthews, Panu Tanninen, Malte Wallmeier, Marek Hauptmann, Kaj Backfolk

Journal of Applied Packaging Research

The micro- and macrostructural changes occurring in multi-layered substrates during three-dimensional forming were studied by atomic force microscopy (AFM), scanning electron microscopy (SEM) and optical analyses. Particular attention was paid to heat-induced deformations at the interface between of polymeric coating layer and the paperboard. With excessive heat transfer, occasional delamination of polyethylene terephthalate (PET) coating from the paperboard was observed. The mechanism behind delamination was studied in detail in-situ with an AFM at temperatures relevant to the converting process. Based on the analysis, the delamination could partially be linked to the widening of the initially-existing nano-scale cracks at the coating-paperboard ...


Photocatalytic Activity: Experimental Features To Report In Heterogeneous Photocatalysis, Md. Ariful Hoque, Marcelo I. Guzman Oct 2018

Photocatalytic Activity: Experimental Features To Report In Heterogeneous Photocatalysis, Md. Ariful Hoque, Marcelo I. Guzman

Chemistry Faculty Publications

Heterogeneous photocatalysis is a prominent area of research with major applications in solar energy conversion, air pollution mitigation, and removal of contaminants from water. A large number of scientific papers related to the photocatalysis field and its environmental applications are published in different journals specializing in materials and nanomaterials. However, many problems exist in the conception of papers by authors unfamiliar with standard characterization methods of photocatalysts as well as with the procedures needed to determine photocatalytic activities based on the determination of “apparent quantum efficiencies” within a wavelength interval or “apparent quantum yields” in the case of using monochromatic ...


The Subject Librarian Newsletter, Engineering And Computer Science, Spring 2018, Buenaventura "Ven" Basco Oct 2018

The Subject Librarian Newsletter, Engineering And Computer Science, Spring 2018, Buenaventura "Ven" Basco

Buenaventura "Ven" Basco

No abstract provided.


The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco Oct 2018

The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco

Buenaventura "Ven" Basco

No abstract provided.


Recent Advances In Study Of Solid-Liquid Interfaces And Solidification Of Metals, Mohsen Asle Zaeem Oct 2018

Recent Advances In Study Of Solid-Liquid Interfaces And Solidification Of Metals, Mohsen Asle Zaeem

Mohsen Asle Zaeem

Solidification occurs in several material processing methods, such as in casting, welding, and laser additive manufacturing of metals, and it controls the nano- and microstructures, as well as the overall properties of the products. Recent advancements in experimental and computational modeling techniques have made it possible to more effectively study atomistic and microscale mechanisms that control the solidification nano- and microstructures, and formation and evolution of solidification defects.


Understanding Homogeneous Nucleation In Solidification Of Aluminum By Molecular Dynamics Simulations, A. Mahata, Mohsen Asle Zaeem, M. I. Baskes Oct 2018

Understanding Homogeneous Nucleation In Solidification Of Aluminum By Molecular Dynamics Simulations, A. Mahata, Mohsen Asle Zaeem, M. I. Baskes

Mohsen Asle Zaeem

Homogeneous nucleation from aluminum (Al) melt was investigated by million-atom molecular dynamics simulations utilizing the second nearest neighbor modified embedded atom method potentials. The natural spontaneous homogenous nucleation from the Al melt was produced without any influence of pressure, free surface effects and impurities. Initially isothermal crystal nucleation from undercooled melt was studied at different constant temperatures, and later superheated Al melt was quenched with different cooling rates. The crystal structure of nuclei, critical nucleus size, critical temperature for homogenous nucleation, induction time, and nucleation rate were determined. The quenching simulations clearly revealed three temperature regimes: sub-critical nucleation, super-critical nucleation ...


Effects Of Specimen Size And Yttria Concentration On Mechanical Properties Of Single Crystalline Yttria-Stabilized Tetragonal Zirconia Nanopillars, Ning Zhang, Mohsen Asle Zaeem Oct 2018

Effects Of Specimen Size And Yttria Concentration On Mechanical Properties Of Single Crystalline Yttria-Stabilized Tetragonal Zirconia Nanopillars, Ning Zhang, Mohsen Asle Zaeem

Mohsen Asle Zaeem

The nanoscale plastic deformation of yttria-stabilized tetragonal zirconia (YSTZ) is highly dependent on the crystallographic orientations, i.e., dislocation is induced when the loading direction is 45° tilted to {111} and {101} slip planes, while tetragonal to monoclinic phase transformation dominates the plastic deformation when loading direction is perpendicular to the slip planes. This study investigates the effects of specimen size and yttria concentration on the mechanical response of single crystalline YSTZ nanopillars. Through uniaxial compression test, the smaller-is-stronger phenomenon is revealed in nanopillars deformed through a dislocation motion mechanism. Serrated stacking faults are observed in the smallest nanopillar, while ...


A Simple Model For Elastic-Plastic Contact Of Granular Geomaterials, Jian Wang, Qimin Li, Changwei Yang, Yidan Huang, Caizhi Zhou Oct 2018

A Simple Model For Elastic-Plastic Contact Of Granular Geomaterials, Jian Wang, Qimin Li, Changwei Yang, Yidan Huang, Caizhi Zhou

Caizhi Zhou

We propose a simple elastic-plastic contact model by considering the interaction of two spheres in the normal direction, for use in discrete element method (DEM) simulations of geomaterials. This model has been developed by using the finite element method (FEM) and nonlinear fitting methods, in the form of power-law relation of the dimensionless normal force and displacement. Only four parameters are needed for each loading-unloading contact process between two spheres, which are relevant to material properties evaluated by FEM simulations. Within the given range of material properties, those four parameters can be quickly accessed by interpolating the data appended or ...


Nanograin Size Effects On The Strength Of Biphase Nanolayered Composites, Sixie Huang, Irene J. Beyerlein, Caizhi Zhou Oct 2018

Nanograin Size Effects On The Strength Of Biphase Nanolayered Composites, Sixie Huang, Irene J. Beyerlein, Caizhi Zhou

Caizhi Zhou

In this work, we employ atomic-scale simulations to uncover the interface-driven deformation mechanisms in biphase nanolayered composites. Two internal boundaries persist in these materials, the interlayer crystalline boundaries and intralayer biphase interfaces, and both have nanoscale dimensions. These internal surfaces are known to control the activation and motion of dislocations, and despite the fact that most of these materials bear both types of interfaces. From our calculations, we find that the first defect event, signifying yield, is controlled by the intralayer spacing (grain size, d), and not the intralayer biphase spacing (layer thickness, h). The interplay of two internal sizes ...


Repeated Loading Model For Elastic-Plastic Contact Of Geomaterial, Jian Wang, Qimin Li, Changwei Yang, Caizhi Zhou Oct 2018

Repeated Loading Model For Elastic-Plastic Contact Of Geomaterial, Jian Wang, Qimin Li, Changwei Yang, Caizhi Zhou

Caizhi Zhou

A new nonlinear hysteretic model with considering the loading, unloading, and reloading processes is developed based on Drucker—Prager yield criterion and finite-element analysis. This model can be used for multiple repeated elastic—plastic normal direction contact problems between two identical spherical geomaterials. After examining the influence of material properties, strain hardening, and loading histories, we found that the hysteretic phenomena (represented by residual displacement and plastic work) become weak after the first cycle, and the subsequent cycles step into elastic shakedown state eventually. A critical number of cycles can be used to estimate the state of ratchetting, plastic shakedown ...


Homogenization Of Plastic Deformation In Heterogeneous Lamella Structures, Rui Yuan, Irene J. Beyerlein, Caizhi Zhou Oct 2018

Homogenization Of Plastic Deformation In Heterogeneous Lamella Structures, Rui Yuan, Irene J. Beyerlein, Caizhi Zhou

Caizhi Zhou

It has been shown that unlike its constituent nanocrystalline (NC) phase, a heterogeneous lamella (HL) composite comprising NC and coarse-grain layers exhibits greatly improved ductility. To understand the origin of this enhancement, we present a 3D discrete dislocation, crystal plasticity finite element model to study the development of strains across this microstructure. Here we show that the HL structure homogenizes the plastic strains in the NC layer, weakening the effect of strain concentrations. These findings can provide valuable insight into the effects of material length scales on material instabilities, which is needed to design heterogeneous structures with superior properties.


Open Source Low-Cost Power Monitoring System, Shane W. Oberloier, Joshua M. Pearce Oct 2018

Open Source Low-Cost Power Monitoring System, Shane W. Oberloier, Joshua M. Pearce

Department of Materials Science and Engineering Publications

This study presents an entirely open-source, low-cost power monitoring system capable of many types of measurements including both loads and supplies such as solar photovoltaic systems. In addition, the system can be fabricated using only open source software and hardware. The design revolves around the Digital Universal Energy Logger (DUEL) Node, which is responsible for reading and properly scaling the voltage and current of a particular load, and then serializing it via an on-board ATTiny85 chip. The configuration of the DUEL node allows for custom sensitivity ranges, and can handle up to 50 A and 300 V. Up to 127 ...


Impacts Of Moisture On Asphalt Properties, Zahid Hossain Oct 2018

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 ...


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 Oct 2018

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 ...