Materials Science and Engineering Commons^™

Solid Loading Effects On The Assembly Of Alumina Particles In Aqueous Suspensions Due To The Dielectrophoretic Forces, Sivakumar Chithamallu, Rohan Kiran Parai, Dipankar Ghosh

Mechanical & Aerospace Engineering Faculty Publications

Current work in situ investigated the mechanisms of the interparticle interactions that evolve in dilute aqueous alumina suspensions subjected to alternating current (AC) electric field and the effects of solid loading of suspensions. The interactions were investigated for alumina suspension compositions in the 0.005‒0.04 vol.% solid loading range. Field‐induced interactions evolved via particle motion and dynamic assembly, chain formation parallel to the direction of the applied field and chain growth, chain cross‐linking, and chain thickening. The evolution time of each of those events was rapidly accelerated with solid loading. While chain cross‐linking was negligible in low solid loading suspensions, a …

Ultrafast Belite (Β-C2s) Production Using Biofuel-Based Combustion Synthesis, Shubham Agrawal, Sayee Srikarah Volaity, Oluwadamilare Charles Adesina, Bryan K. Aylas-Paredes, Taihao Han, Srinivas Kilambi, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

This study presents a novel low-temperature, combustion synthesis (CS) approach for the rapid production of belite-rich cements. CS leverages the exothermic heat released from the combustion of biofuels such as lignin and/or biomass, intermixed with pelletized limestone and quartz. At an imposed furnace temperature of ∼700°C (as opposed to 1200°C–1300°C required in a conventional kiln), the source materials are rapidly transformed to belite, resulting in energy, emissions, and economic benefits. This work explores the influence of various process parameters, viz., fuel types and contents, airflow rate, porosity, holding temperature, and holding time on the efficiency of CS-based belite synthesis. Through …

Flexural Response Of Inflatable Drop-Stitch Panels, Alex J. Watterson

Open Access Master's Theses

All CUI (Controlled Unclassified Information) is U.S. government property and has been removed from this thesis.

Evaluation Of Polymer Coated Fabrics Subjected To Various Multiaxial Stress States, Shane Marx

Open Access Master's Theses

All CUI (Controlled Unclassified Information) is U.S. government property and has been removed from this thesis.

Atomistic Calculations Characterizing Thermodynamic And Mechanical Properties Of High Entropy Alloys, Sarah O'Brien

Theses and Dissertations--Chemical and Materials Engineering

High entropy alloys (HEAs) are an exciting new class of materials. HEAs combine multiple elements in concentrations ranging from 5% to 35%. The large variation in concentrations increases the alloy’s entropy, stabilizing it. The stabilization is due to both an increased configurational entropy and increases the vibrational entropy when the alloy is at higher temperatures. This was seen for both MoNbTaW and FeNiMoW by combining the atomistic techniques: density functional theory (DFT) and density functional perturbation theory (DFPT). For MoNbTaW, the composition plays a large role in stabilizing the alloy over the configuration of elements. For the three-phase alloy, FeNiMoW, …

Analysis Of Ptfe Radial Lip Seals For Wheel Bearing Applications, Madison Vogt

Theses and Dissertations--Mechanical and Aerospace Engineering

A numerical analysis was conducted to investigate the viscoelastic effects of nonlinear materials on the sealing zone and contact pressure distribution of radial lip seals in a conventional geometric topology. The use of nonlinear materials in radial lip seal applications is desirable to improve operation and reliability of rotating machinery due to their high operating temperatures, chemical compatibility, and low friction coefficients. Examples include, but are not limited to, seals within industrial air compressors, turbine engines, aircraft landing systems, chemical processing equipment, and Freon pumps. This work focuses on analyzing the nonlinear viscoelastic response of pure Polytetrafluoroethylene (PTFE) and PTFE …

Growth Kinetics And Stability Of Metal Halide Perovskite Nanocrystals: Influence Of Stirring Speed And Water Exposure, You-Lin Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Cesium lead bromide (CsPbBr₃) perovskite nanocrystals (NCs) have garnered significant interest due to their exceptional optoelectronic properties, including high photoluminescence quantum yield, tunable bandgap, and excellent carrier dynamics. These attributes make them promising candidates for applications in light-emitting diodes, photovoltaics, and sensing technologies. However, optimizing their synthesis and improving their environmental stability remain critical challenges. This dissertation explores the growth kinetics of CsPbBr₃ NCs, focusing on the effects of stirring speed and water exposure on their structural and optical properties.

The synthesis of CsPbBr₃ NCs was performed using both mechanochemical (MC) and antisolvent methods, enabling an …

3d Printing Of A Solid-State Battery, Maurizio A. Brozzi

Honors Undergraduate Theses

Solid-state battery research has gained significant attention in recent years, as it provides a unique solution for several common issues in conventional Li-ion batteries. Additionally, as additive manufacturing technologies continue to advance, they have the potential to fabricate solid-state batteries with new materials. The objective of this study is to explore the feasibility of 3D printing of a solid-state battery. By creating an initial PEO-PSF hybrid polymer matrix dissolved in DMSO and adding a lithium salt, the base electrolyte ink was formed. With the addition of conductive additives and active material, electrode inks were also produced. Super P was used …

Synthesis And Characterization Of Multifunctional Cerium Oxide Containing Nanoparticles For Biomedical Applications, Ishaan Patel

Honors Undergraduate Theses

This study presents the synthesis and comprehensive characterization of a novel core-shell nanoparticle composed of a maghemite (γ-Fe₂O₃) core and a europium-doped cerium oxide (EuCNP) shell, developed for potential use in cancer theranostics. Using a co-precipitation method, Fe₂O₃–EuCNP core-shell nanoparticles were synthesized and compared against control samples of CNPs, EuCNPs, and Fe₂O₃. A variety of characterization techniques, including UV-Vis spectroscopy, fluorescence spectroscopy, TEM, XRD, XPS, DLS, TGA, and DSC confirmed the successful synthesis of core-shell architecture and europium doping. Moreover, Fe₂O₃–EuCNPs demonstrating strong colloidal …

Fabricating Silver-Ceria Polymer Nanocomposite Scaffolds For Biomedical Therapeutic Applications, Shreya S. Pawar

Honors Undergraduate Theses

Improper healing of bone fractures and limited regeneration of bone following bone tumor resection remain a prevalent complication worldwide. Long-term effects of this include joint instability, limited movement, and arthritis. Bone infections (osteomyelitis), reactive oxygen species (ROS) generation via excessive inflammation, and underlying conditions such as osteoporosis can contribute to suboptimal bone tissue regeneration. ROS accumulation stimulates osteoblast apoptosis, while promoting osteoclast differentiation. These processes inhibit mineralization and osteogenesis. Conventional therapeutics involve the utilization of drugs and bone grafts. However, these approaches pose limitations and can result in subsequent complications. Microbial infections, ROS accumulation, and excessive inflammations are factors that …

Fabrication And Characterization Of Cast Copper Heatsinks For Computer Chip Cooling, John James Recktenwald

Graduate Theses, Dissertations, and Problem Reports (ETD)

Humanity has worked copper for millennia, from primitive tools in prehistory to the wires and cooling solutions facilitating the modern digital age. While high performance fin style heatsinks are commonplace, more complex heatsink geometries in high performance applications are rare due to manufacturing challenges. In this study a casting process was developed to fabricate copper pin fin heatsinks. To assess the performance of heatsinks fabricated using the process three pin fin heatsinks were fabricated, one machined from a commercially manufactured billet, one machined from a cast block, and one cast directly to final shape. Each of the three heatsinks were …

Electro-Mechanical Behavior Of Core-Shell Carbon Grease-Silicone Fibers Fabricated Via Coaxial Direct Ink Writing, Fahrettin Kilic

Graduate Theses, Dissertations, and Problem Reports (ETD)

Highly stretchable strain sensors are essential components in soft electronics, enabling integration of sensing and signal transmission into deformable systems. This thesis explores the fabrication and characterization of coaxial core–shell fibers composed of a conductive carbon grease core and an elastomeric silicone shell. These fibers were produced using coaxial direct ink writing (DIW), a versatile additive manufacturing technique that allows continuous deposition of multi-material filaments. The goal was to achieve mechanically compliant yet electrically stable fibers capable of withstanding large deformations, suitable for applications in wearable electronics and soft robotics.
The printed fibers were systematically examined through mechanical tensile testing, …

Microwave-Assisted Reduction Of Critical Metal Oxides From E-Waste Mixture, Kurundu Shavinka Jayasekera

Graduate Theses, Dissertations, and Problem Reports (ETD)

The efficient recovery of critical metals such as tantalum (Ta), manganese (Mn), gallium (Ga), and indium (In) from electronic waste (e-waste) is essential for resource sustainability and environmental protection. This research uses microwave-assisted treatment to investigate the carbothermal reduction of these four specific metals from their oxides in a simulated e-waste mixture, with carbon black serving as both a microwave coupling and reduction agent. Microwave processing is used specifically because it offers a rapid and energy-efficient alternative to conventional thermal methods, with the benefits of intrinsic heating and selective heating of materials. The first experiments centered on understanding the effects …

Polymeric Nanocomposites-Based Advanced Coatings For Antimicrobial And Antiviral Applications: A Comprehensive Overview, Rachid Amrhar, Jaspal Singh, Mostafa Eesaee, Pascal Carrière, Alireza Saidi, Phuong Nguyen-Tri

Revues de littérature, synthèses de connaissances

The rise in microbial infections and viral outbreaks has accelerated the development of advanced antibacterial and antiviral coating that effectively minimize infection risks. Amidst rising global health concerns due to infectious diseases, these coatings have emerged as vital solutions for surface protection across various settings. This review focuses on the recent development and in-depth analysis includes synthesis process, inactivation mechanism in photoreactive antimicrobial and antiviral bio-coatings. This review comprehensively explores the development of different nanocomposite materials, including polymers based on metal oxide nanoparticles, metal nanoparticles, graphene-based materials, and organic-inorganic composites. Their practicality and compatibility with diverse surfaces such as ceramics, …

Epitaxial Quantum Dot Scintillators With Monolithic Photodetector Integration: Physics, Fabrication And Characterization Of Materials And Devices, Allan Oreave Minns

Electronic Theses & Dissertations (2024 - present)

This dissertation discloses the physics, fabrication, and characterization of high-performance scintillator detectors based on epitaxial InAs quantum dots (QDs) in GaAs. The detector crystals grown include monolithically integrated In_0.35GaAs photodetectors with Al_0.92-0.6In_0.03-0.35Ga_0.05As metamorphic buffer layers (MBL). A device fabrication process was developed for the lithographic patterning, chemical etching, contact metallization and readout integration of materials grown by means of molecular beam epitaxy (MBE) on 3-inch GaAs (001) wafers. Low capacitance integration with readout electronics was achieved through wire bonds to custom printed circuit boards (PCBs) with commercial components.

The relationship between device …

Effect Of Build Orientation On Tensile Properties And Fractography Of Additive Manufactured Inconel 718 Alloy, Ajay Kumar Maurya, Amit Kumar, Swarnambuj Suman

ASEAN Journal on Science and Technology for Development

The additive manufacturing (AM) technique “Direct Metal Laser Sintering (DMLS)” is used to create 3D objects directly from 3D design data. A lightweight and complexity-free part without any expensive tooling can be fabricated easily using this method, but it is still challenging to achieve the desired mechanical strength from AM parts, as the mechanical properties of AM-produced parts vary with orientation, scan strategy, and process parameters. Inconel 718 alloy is most commonly utilized in the aerospace and automotive industries, because of its high resistance to corrosion and excellent mechanical qualities. This work presents a study to investigate the orientation-based mechanical …

Design And Manufacturing Of Multifunctional Piezoelectric Composites, Huan Zhao

Dartmouth College Ph.D Dissertations

Piezoelectric materials possess a unique ability to convert mechanical energy into electrical signals and have broad industrial applications. However, monolithic piezoelectric materials such as piezoceramics and piezopolymers often suffer from inherent trade-offs among mechanical strength, elasticity, and durability. Piezoelectric composites, typically consisting of a polymer matrix with ceramic reinforcements, offer a solution by combining the advantages of each constituent. Nevertheless, maintaining stable mechanical performance in high-temperature environments remains a significant challenge as conventional polymer matrices usually experience structural degradation.

In this thesis, a novel piezoelectric composite is developed using a preceramic polymer (PCP) matrix with barium titanate (BTO) inclusions. PCPs …

Improving The Figure Of Merit In Iron-Vanadium-Aluminium Thermoelectric Alloy System Guided By Computational Modeling, Tao Fang

Dartmouth College Ph.D Dissertations

Thermoelectric materials can convert a thermal gradient to electricity. Currently, commercialized Bi₂Te₃ is brittle and expensive, which restricts the usage of this material. Compared to other thermoelectric materials, Fe₂VAl is cost-effective, stable and more robust mechanically. However, the figure of merit (zT) had been much lower than Bi₂Te₃. In this thesis, our main goal is to improve the figure of merit in Fe₂VAl system guided by computational modeling. We will start the discussion by presenting the Ge doped Fe₂VAl sample with record thermoelectric figure of merit value. …

Characterization And Leaching Feasibility Studies Of Copper Flue Dust For The Recovery Of Main And Trace Metals, Fardis Nakhaei, Marek Locmelis, Lana Alagha, Michael S. Moats, Carlos Eyzaguirre, Cory Smith

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Although copper smelter dust (CSD) is classified as hazardous waste, it also serves as a valuable secondary resource, offering potential for the recovery of critical elements. In this study, CSD samples were collected from the waste heat boiler (WHB) and electrostatic precipitator (ESP) units connected to the flash smelting furnace at a copper smelter. The representative samples were extensively characterized by particle size, and chemical and mineralogical analyses. Following sample characterization, leaching experiments were performed to evaluate the potential extraction of Cu, Fe, As, Zn, Pb, In, Ga, and Ge from the flue dusts. Distilled water, H2SO4, and HCl were …

Photocatalytic Performance Of Ba₀.₈Ca₀.₂Tio₃ Composite For Norfloxacin Removal In Aqueous Solutions, Raj Mohanty, Swayam Aryam Behera, Asima Subhadarshini, Binita Nanda, P. Ganga Raju Achary

Journal of Metals, Materials and Minerals

This study investigates the degradation of norfloxacin using a Ba0.8Ca0.2TiO3 (BCTO) perovskite composite synthesized via a simple solid-state method. Variety of characterization techniques, including photoluminescence spectra, powder X-Ray Diffraction, UV-Vis Diffuse Reflectance Spectra, FE-SEM and Fourier-Transform Infrared spectra confirm the structural and optical properties of BCTO. Electrical characterization further elucidates its conductive properties. The BCTO composite demonstrates an impressive 87% degradation rate of norfloxacin, attributed to its reduced electron-hole recombination, enhanced light harvestation, and improved charge carrier mobility. Kinetic studies indicate that the degradation process adheres to a pseudo-first-order model, with BCTO outperforming both pure BaTiO3 and conventional photocatalysts. These …