Engineering Commons^™

Assessing Magnetic Iron Oxide Nanoparticles Properties Under Different Thermal Treatments, Erick S. Vasquez, Evan M. Prehn, Keisha B. Walters

Chemical and Materials Engineering Faculty Publications

Magnetic nanoparticle structures have been examined as potential carrier vehicles and substrates in a wide range of applications where they undergo mechanical, chemical and/or thermal manipulation to allow for their modification, conjugation and transport. For safe and effective use, it is imperative to not only measure the initial physicochemical and structural properties of nanomaterials, but also identify and quantify any property changes related to a loss of chemical and/or physical integrity during processing and usage conditions. In this study an assessment of iron oxide magnetic nanoparticle thermal stability using modulated differential scanning calorimetry (mDSC) and a controlled-heating system is conducted …

Effect Of Incorporating Pottery And Bottom Ash As Partial Replacement Of Cement, Bassam A. Tayeh, Doha M. Alsaffar, Lawend K. Askar, Asmahan Issa Jubeh

Karbala International Journal of Modern Science

This study addressed the environmental constraints in cement produc­tion. Ordinary Portland cement (OPC) was replaced with pottery powder (PP, produced by grinding locally available pottery) and bottom ash (BA) at 10%, 20% and 30% of cement mass. Moreover, 4% calcium chloride solution (CaCl₂.2H₂O) was used as mixing water. Material properties, such as standard consistency, setting time and compressive strength, were measured with different percentages of OPC replacement with PP and BA. Results indicated that the replacement with PP and BA increased the water demand to achieve the standard consistency. These results revealed that the strength evolution …

Nanoscale Optical And Correlative Microscopies For Quantitative Characterization Of Dna Nanostructures, Christopher Michael Green

Boise State University Theses and Dissertations

Methods to engineer nanomaterials and devices with uniquely tailored properties are highly sought after in fields such as manufacturing, medicine, energy, and the environment. The macromolecule deoxyribonucleic acid (DNA) enables programmable self-assembly of nanostructures with near arbitrary shape and size and with unprecedented precision and accuracy. Additionally, DNA can be chemically modified to attach molecules and nanoparticles, providing a means to organize active materials into devices with unique or enhanced properties. One particularly powerful form of DNA-based self-assembly, DNA origami, provides robust structures with the potential for nanometer-scale resolution of addressable sites. DNA origami are assembled from one large DNA …

Study Of Amorphous Boron Carbide And Hydrogenated Boron Carbide Materials Using Molecular Dynamics And Hybrid Reverse Monte Carlo, Rajan Khadka

MSU Graduate Theses

We present a computational study of amorphous boron carbide (a-B_xC) models using Molecular Dynamics (MD) studied with Stillinger-Weber (SW) and ReaxFF potential. The atomic structure factor (S(Q)), radial distribution function (RDF) and bond lengths comparison with other experimental and ab initio models shows that a random arrangement of icosahedra (B₁₂, B₁₁C) interconnected by chains (CCC, CBC) are present in a-B_xC. Afterward, Hybrid Reverse Monte Carlo (HRMC) technique is used to recreate a-B_xC structures. The existing SW potential parameters of Boron are optimized for the α-rhombohedral (Icosahedral B_{12 …}

Effects Of Magnetic Domain And Twin Boundary Interactions On Magneto-Mechanical Properties Of Magnetic Shape Memory Alloys, Medha Veligatla

Boise State University Theses and Dissertations

Magnetic shape memory (MSM) alloys deform substantially when exposed to a magnetic field. This recoverable plastic deformation occurs through crystallographic twinning. Thereby the internal magnetic domain structure modulates the deformation mechanisms through the interaction of magnetic domains with twin boundaries. We study the meso scale magneto-structural interactions that affect the macroscopic material properties of MSM alloys. The study at the meso length scale is most effective as it allows for resolving interactions at magnetic domain wall width resolution with reasonable computing cost. We apply micromagnetics simulations to evaluate the evolution of magnetic domains, their interaction with twin boundaries, the distribution …

Micromechanics Of Plasticity Of Zr-2.5%Nb Alloy, Md Imran Khan

Electronic Thesis and Dissertation Repository

Zirconium alloys are used in many thermal neutron fission reactors because of their very low neutron interaction cross-sections along with their excellent mechanical strength and corrosion resistance. Numerous experiments have been conducted on these alloys at the bulk scale to determine their mechanical properties. Recent advancements in micro-mechanical testing make it easier to study site-specific mechanical properties for micron or submicron-sized samples. Understanding the mechanical response of such small volumes of material is extremely important for developing accurate models to predict the ductile fracture toughness of these in-reactor materials. Pressure tubes made of Zr-2.5%Nb alloys are an integral part of …

Combined Molecular Dynamics And Phase Field Simulation Of Crystal Melt Interfacial Properties And Microstructure Evolution During Rapid Solidification Of Ti-Ni Alloys, Sepideh Kavousi

LSU Doctoral Dissertations

Phase field method has become a popular tool to investigate the microstructure evolution during the solidification. Quantitative predictions using this method is still limited, and in this dissertation, we try to study this problem from different perspectives.

Most of the phase field models consider the solid-liquid interface to be in local equilibrium. Solidification during some manufacturing processes like selective laser melting, and electron beam additive manufacturing is rapid and far from equilibrium which can result in supersaturated solid solutions, segregation-free crystals, or metastable phases. Before obtaining any conclusions from the phase field simulations, we must know the answer for “which …

Why The Crackling Deformations Of Single Crystals, Metallic Glasses, Rock, Granular Materials, And The Earth’S Crust Are So Surprisingly Similar, Karin A. Dahmen, Jonathan T. Uhl, Wendelin J. Wright

Faculty Journal Articles

Recent experiments show that the deformation properties of a wide range of solid materials are surprisingly similar. When slowly pushed, they deform via intermittent slips, similar to earthquakes. The statistics of these slips agree across vastly different structures and scales. A simple analytical model explains why this is the case. The model also predicts which statistical quantities are independent of the microscopic details (i.e., they are "universal"), and which ones are not. The model provides physical intuition for the deformation mechanism and new ways to organize experimental data. It also shows how to transfer results from one scale to another. …

The Effect Of Calcium Nitrate On The Hydration Of Calcium Aluminate Cement At Different Curing Temperatures, Hongxia Wang, Guizhi Diao, Guanghua Liu, H Wang, Lixiong Gao, Guangwei Liu

International Conference on Durability of Concrete Structures

Phase conversion in calcium aluminate cements (CAC) induces significant volumetric instability; it would result in an increase in porosity and decrease in strength in CAC. In this study, calcium nitrate (CN) as a phase conversion inhibitor, the effect of CN on the hydration of CAC at different curing temperatures was studied. Xray diffraction, thermal analysis, SEM, isothermal calorimetry and the compressive strength were conducted on the CAC dosages of 0%, 5%, 10% and 15%CN cured at 20�, 30�, 40� and 50�. The results show CN can retard CAC hydration, alter the characters of the hydrates of CAC systems and avoid …

An Investigation Of High-Speed Consolidation And Repair Of Carbon Fiber - Epoxy Composites Through Ultrasonic Welding, David A. Hoskins

LSU Master's Theses

Adhesive repair of carbon fiber composite structures is commonly done on damaged structures to extend the service life. This method requires careful preparation of the damaged surface with intricate steps to ensure good bonding between the repair patch and the parent structure by means of an adhesive film. As with many forms of composite manufacturing, it is required to perform vacuum bagging, debulking, and a heated cure depending on the resin. All these steps make the repair process costly and time consuming.

In this present work, an alternative method of repair is investigated which explores the experimental feasibility of using …

Effect Of Ion Implantation On The Mechanical Properties Of The Grain And Grain Boundary Regions Of Inconel X750, Maisaa Nezar Tawfeeq

Electronic Thesis and Dissertation Repository

Annulus gas spacers in CANada Deuterium Uranium (CANDU) nuclear reactors are made from the heat-treated Inconel X750 Nickel-based alloy. This alloy is designed to have high strength and creep resistance at elevated temperature. Unlike other reactor designs, the CANDU reactor has a high thermal neutron fluence, which results in an enhancement of the radiation damage and the internal production of helium and hydrogen. They are thus susceptible to microstructural instability and mechanical property degradation with time. Studies of ex-service spacers have indicated that they display intergranular embrittlement and lower ultimate tensile strength compared to nonirradiated Inconel X750. The primary degradation …

Optothermal Microbubble Assisted Manufacturing Of Nanogap-Rich Structures For Active Chemical Sensing, Farzia Karim, Erick S. Vasquez, Yvonne Sun, Chenglong Zhao

Chemical and Materials Engineering Faculty Publications

Guiding analytes to the sensing area is an indispensable step in a sensing system. Most of the sensing systems apply a passive sensing method, which waits for the analytes to diffuse towards the sensor. However, passive sensing methods limit the detection of analytes to a picomolar range on micro/nanosensors for a practical time scale. Therefore, active sensing methods need to be used to improve the detection limit in which the analytes are forced to concentrate on the sensors. In this article, we have demonstrated the manufacturing of nanogap-rich structures for active chemical sensing. Nanogap-rich structures are manufactured from metallic nanoparticles …

Biopolymer-Stabilized Earth Materials For Resilient And Adaptable Infrastructures, Sherif Abdelaziz, Dilip Gersappe, Dilip Rafailovich

Department of Civil Engineering Faculty Publications

Earth dams and levees are constructed and retrofitted nowadays using the same materials that were used in the past, clays and sands. Despite the current advances in engineering, designing and constructing these critical infrastructure, earthen dams and levees continue to suffer from the same challenges over the years. These challenges include internal and surface erosions, loss of stability due to moisture migration, and inabilities to self-heal potential failure points. This project focuses on the use of biopolymers as additives to strengthen earthen dams and levees targeting an overall increase in their resilience.

Explicitly, the report for Milestone 3 presented the …

Optimization And Structural Stability Of Gold Nanoparticle–Antibody Bioconjugates, Robert T. Busch, Farzia Karim, John Weis, Yvonne Sun, Chenglong Zhao

Chemical and Materials Engineering Faculty Publications

Gold nanoparticles (AuNPs) bound with biomolecules have emerged as suitable biosensors exploiting unique surface chemistries and optical properties. Many efforts have focused on antibody bioconjugation to AuNPs resulting in a sensitive bioconjugate to detect specific types of bacteria. Unfortunately, bacteria thrive under various harsh environments, and an understanding of bioconjugate stability is needed. Here, we show a method for optimizing Listeria monocytogenes polyclonal antibodies bioconjugation mechanisms to AuNPs via covalent binding at different pH values, from 2 to 11, and 2-(N-morpholino)ethanesulfonic acid (MES), 3-(N-morpholino)propanesulfonic acid, NaOH, HCl conditions. By fitting Lorentz curves to the amide I and II regions, we …

Shape-Controlled Nanoparticles As Effective Catalysts For Proton Exchange Membrane (Pem) Fuel Cells, Ali Feizabadi

Electronic Thesis and Dissertation Repository

Polymer electrolyte membrane fuel cell (PEMFC), is considered a promising candidate for the next generation power sources in transportation, stationary and portable applications. However, oxygen reduction reaction (ORR), one of the key reactions occurring on PEMFC is kinetically slow; this has limited performance and further advancement in this kind of fuel cells. Thus, improving the PEMFC efficiency requires a thorough understanding of the ORR mechanism on the desired catalyst. To address the above-mentioned demands, the scope of this thesis is focused on the fundamental understanding of facet-controlled nanoparticles, metal-support interactions, and bimetallic platinum catalysts, utilizing synchrotron-based X-ray absorption, X-ray photoelectron …

Mitigating Reflective Cracking Through The Use Of A Ductile Concrete Interlayer, Qian Zhang, Mohammad Khattak, Adway Das

Publications

Reflective cracking is considered one of the most important issues that causes premature deterioration of composite pavements. Many types of mitigation methods have been studied in the past. However, they are either not effective in delaying the reflective cracking, or they only extend the service life by a few years. To address this critical issue and significantly extend the service life of the composite pavement, in this research, a ductile interlayer made of engineered cementitious composites (ECC) was proposed. It was hypothesized that by adding a thin layer of highly ductile ECC material between the existing pavement and overlay, reflective …

Computational And Experimental Approach To Understanding The Structural Interplay Of Self-Assembled End-Terminated Alkanethiolates On Gold Surfaces, Juganta K. Roy, Erick S. Vasquez, Henry P. Pinto, Swati Kumari, Keisha B. Walters, Jerzy Leszcynski

Chemical and Materials Engineering Faculty Publications

Applications of self-assembled monolayers (SAMs) on surfaces are prevalent in modern technologies and drives the need for a better understanding of the surface domain architecture of SAMs. To explore structural interaction at the interface between gold surfaces and a hydroxyl-terminated alkanethiol, 11-hydroxy-1-undecanethiol, (C11TH) we have employed a combined computational and experimental approach. Density functional theory (DFT) calculations were carried out on the thiol–gold interface using both the Perdew–Burke–Ernzerhof (PBE) and van der Waals (optB86b) density functionals. Our ab initio molecular dynamics (AIMD) simulations revealed that the interface consists of four different distinguished phases, each with different C11TH orientations. Experiments involved …

Interfacial Interactions And Dynamic Adhesion Of Synthetic And Living Colloids In Flow, Molly Shave

Doctoral Dissertations

This thesis focuses on the interactions between flowing particles and a surface, where hydrodynamics couples with chemical interactions in order to modify the way they come into play. First this thesis shows how electrostatic chemical heterogeneities on a flowing particle affect the interactions with a wall, using a highly tunable electrostatically heterogenous system produced by adsorbing small amounts of cationic polyelectrolytes onto silica particles in suspension and studying their behavior in flow over the fixed surface. By comparing this behavior to a system with equivalent chemical heterogeneity on a channel wall it was shown that the rotation of a particle …

Hydcem: A New Cement Hydration Model, Niall Holmes, Denis Kelliher, Mark Tyrer

Conference papers

Hydration models are useful to predict, understand and describe the behaviour of different cementitious-based systems. They are indispensable for undertaking long-term performance and service life predictions for existing and new products for generating quantitative data in the move towards more sustainable cements while optimising natural resources. One such application is the development of cement-based thermoelectric applications.

HYDCEM is a new model to predict the phase assemblage, degree of hydration, heat release and changes in pore solution chemistry over time for cements undergoing hydration for any w/c ratio and curing temperatures up to 450C. HYDCEM, written in MATLAB, is aimed at …

Optimizing The Valorization Of Industrial By-Products For The Induction Healing Of Asphalt Mixtures, Amir Tabakovic, Marta Vila-Cortavitarte, Daniel Jato-Espino, Daniel Castro-Fresno

Articles

Self-healing within asphalt pavements is the process whereby road cracks can be repaired automatically when thermal and mechanical conditions are met. To accelerate and improve this healing process, metal particles are added to asphalt mixtures. However, thisapproach is costly both in economic and environmental terms due to the use of virgin metallic particles. So, even though the self-healing of asphalt mixtures has been widely addressed in experimental terms over the years, there is a lack of research aimed at modelling this phenomenon, especially with the purpose of optimizing the use of metal particles through the valorization of industrial by-products. As …

Development Of Experimental And Finite Element Models To Show Size Effects In The Forming Of Thin Sheet Metals, Jeffrey D. Morris

University of New Orleans Theses and Dissertations

Abstract

An experimental method was developed that demonstrated the size effects in forming thin sheet metals, and a finite element model was developed to predict the effects demonstrated by the experiment. A universal testing machine (UTM) was used to form aluminum and copper of varying thicknesses (less than 1mm) into a hemispherical dome. A stereolithography additive manufacturing technology was used to fabricate the punch and die from a UV curing resin. There was agreement between the experimental and numerical models. The results showed that geometric size effects were significant for both materials, and these effects increased as the thickness of …

Development Of A Methodology For Characterizing Reaction Kinetics, Rheology, And In-Situ Compaction Of Polyimide Prepregs During Cure, James Raymond Magato, Donald A. Klosterman

Chemical and Materials Engineering Faculty Publications

PMR-type polyimide prepregs are challenging to fabricate into high quality composites due to volatiles that are generated and must be removed in situ during processing. The current work was conducted to develop accurate, reliable, and practical characterization techniques of the prepreg rheology, volatile generation, and subsequent volatile removal from the prepreg during composite fabrication. Thermal analysis was used to characterize volatile generation, reaction rates, and rheology. A novel approach was used to measure the thickness of the prepreg in situ during vacuum bag/oven processing using a high-temperature LVDT. Experimental results are presented for the commercially available RM-1100 polyimide/carbon prepreg system, …

Elimination Of Empirical, Ineffective And Expensive Pg Plus Tests To Characterize Modified Binders, Zahid Hossain, Ashraf Elsayed, Mm Tariq Morshed, Mohammad Hassan

Data

Corresponding data set for Tran-SET Project No. 18BASU02. Abstract of the final report is stated below for reference:

"For characterizing the polymer modified binders, different state Departments of Transportation (DOTs) use different time consuming and empirical Performance Grade (PG) Plus test methods. Furthermore, the PG Plus tests are silent when asphalt binders are modified with chemicals such as polyphosphoric acid (PPA). But, the effects of the elastomeric or plastomeric polymer are not accurately identified through these conventional tests such as Elastic Recovery (ER) and tenacity. Thus, the main research goal of this study is to recommend alternative test method(s), which …

Self-Healing Concrete Using Encapsulated Bacterial Spores In A Simulated Hot Subtropical Climate, Marwa Hassan, Jose Milla, Tyson Rupnow, Ahsennur Soysal

Publications

Bacterial concrete has become one of the most promising self-healing alternatives due to its capability to seal crack widths through microbial induced calcite precipitation (MICP). In this study, two bacterial strains were embedded at varying dosages (by weight of cement) in concrete. Beam specimens were used to identify the maximum crack-sealing efficiency, while cylinder samples were used to determine their effects on the intrinsic mechanical properties, as well as its stiffness recovery over time after inducing damage. The concrete specimens were cured in wet-dry cycles to determine their feasibility in Region 6. The results showed that the specimen groups with …

Elimination Of Empirical, Ineffective And Expensive Pg Plus Tests To Characterize Modified Binders, Zahid Hossain, Ashraf Elsayed, Mm Tariq Morshed, Mohammad Hassan

Publications

For characterizing the polymer modified binders, different state Departments of Transportation (DOTs) use different time consuming and empirical Performance Grade (PG) Plus test methods. Furthermore, the PG Plus tests are silent when asphalt binders are modified with chemicals such as polyphosphoric acid (PPA). But, the effects of the elastomeric or plastomeric polymer are not accurately identified through these conventional tests such as Elastic Recovery (ER) and tenacity. Thus, the main research goal of this study is to recommend alternative test method(s), which can possibly be pursued by using a commonly available device, a Dynamic Shear Rheometer (DSR). Three PG binders …

Use Of Rice Husk Ash (Rha) In Flowable Fill Concrete Mix Material, Zahid Hossain, Kazi Tamzidul Islam

Publications

In the way of finding sustainable development, the flowable fill is a relatively new construction technology. Flowable fill is a self-compacting material, which has been developed in recent years. Flowable fill has been used for different applications such as backfilling walls, sewer trenches, bridge abutments, conduit trenches, pile excavations, and retaining walls. This study examines the potential uses of Rice Husk Ash (RHA) as a sustainable cementitious material (SCM) in the preparation of flowable fill concrete. (RHA is an agricultural by-product of the rice milling process. This study has evaluated the usage of RHA in producing low strength and self-consolidating …

Use Of Bagasse Ash As A Concrete Additive For Road Pavement Application, Gabriel Arce, Marwa Hassan, Maria Gutierrez, Michele Barbato

Publications

The objective of this study was to evaluate the use of sugarcane bagasse ash (SCBA) as a partial replacement of cement in concrete for road pavement application. The study explored the pozzolanic activity of SCBA produced from three different processing methodologies (i.e., raw SCBA, controlled SCBA and post-processed SCBA). The experimental results revealed that SCBA produced by the controlled burning of sugarcane bagasse fiber (SBF) at 650°C and grinding (C-650), presented the maximum pozzolanic activity. However, this SCBA production process was deemed challenging for large-scale industrial application due to low SCBA yield (i.e., 3 to 6%). On the other hand, …

Enhanced Carbon Fiber-Epoxy Composites For Rowing Racing Shells, Rayehe Samimi

Electronic Thesis and Dissertation Repository

This thesis investigates the thermomechanical properties of two commercial composites using carbon fiber reinforcement in epoxy resins for manufacturing marine based rowing racing shells. The main goal of this project was to investigate how to control the resin properties and curing temperatures to improve the final product properties including adhesion, toughness modulus and tensile strength. Moreover, an efficient curing process was required by our supporting company to be used at low temperatures to enhance the curing characteristics and to provide improved mechanical properties. Accordingly, the current research tries to improve the manufacturing curing process and build up high performance structure …

Mechanical Performance Of Structural Systems With Missing Members: From Buildings To Architected Materials, Panagiotis Pantidis

Doctoral Dissertations

Structural systems are potentially subjected to damage initiating scenarios throughout the course of their service time. Depending on the nature and extent of the damaging event, they may experience significant reduction or even complete loss of their mechanical performance. This dissertation delves into the mechanics of structural systems under the notion of missing members from their domain, investigating types of structural systems: a) multi-story steel framed buildings, and b) materials with a truss-lattice microstructure. Part I of the dissertation investigates the performance of multi-story steel framed buildings under a column removal scenario, developing an analytical framework for their quasi-static robustness …

Manipulating Fiber Orientation For The Reduction Of Warpage In Carbon Fiber Composite Sandwich Panels, Landon Burnley, Gabrielle Correia

Materials Engineering

Safran Cabin (Santa Maria, CA), previously known as Zodiac Aerospace, designs and manufactures interior cabin components for private and commercial aircraft. Carbon fiber face sheets have recently been incorporated in their overhead luggage bin assemblies which utilize a composite sandwich panel design, in order to provide additional stiffness to the previous glass fiber sandwich panels. Since the introduction of carbon fiber in these luggage bin panels, Safran has experienced an increase in warpage during manufacturing. When inspected by quality control, the panels are tested mimicking how they are installed in aircraft. If the panels do not meet specifications, the warped …