Materials Science and Engineering Commons^™

The Impact Of Contact Geometry On Sea Ice Stress And Fracture At The Scale Of Ice Floes, Michael J. May

Dartmouth College Master’s Theses

Observations of stress and strain at the scale of ice floes are necessary to fill a gap in our understanding of sea ice mechanical behavior. Current climate and ice dynamics models represent ice mechanical properties using stress-strain relationships largely determined at laboratory-scale (<1m) or from regional-scale (10+km) deformation observations. The former scale does not include all mechanisms of deformation operating in the ice pack; the latter aggregates multiple modes of deformation into non-physical fluid analogies. The Sea Ice Dynamics Experiment (SIDEx) was run in Feb-Mar 2021 to fill this gap, observing stress and strain at the scale of sea ice failure processes. Here we present stress sensor observations. Stress gages (N=31) were deployed over a 4.5km² area in the southern Beaufort Sea to observe in-situ stress. These data were analyzed in the context of deformation observations from satellite imagery and local laser and radar interferometers to explain the drivers of sea ice stress variations before and after fracture. Three case studies between 14 March and 24 March, during which fractures propagated through …

Sustainable Material For Urea Delivery Based On Chitosan Cross-Linked By Glutaraldehyde Saturated Toluene: Characterization And Determination Of The Release Rate Mathematical Model, Jayanudin Jayanudin, Retno S. D. Lestari, Indar Kustiningsih, Dandi Irawanto, Rozak Rozak, Reyonaldo L. A. Wardana, Fakhri Muhammad

Karbala International Journal of Modern Science

The aims of this study were to characterize the urea-loaded chitosan microspheres and determine the release kinetic constants and diffusion coefficients. An emulsion cross-linking method was used to prepare the urea-loaded chitosan microspheres. Urea was dissolved in a solution of chitosan then put into vegetable oil and stirred to form an emulsion. Glutaraldehyde saturated toluene (GST) was added into the emulsion dropwise while continuously stirring for the solidification process. Chitosan microspheres filled with urea were washed, dried, and then analyzed. Characterization of the urea-loaded chitosan microspheres was conducted using a scanning electron microscope (SEM), Raman spectroscopy, X-ray diffraction, and particle …

Image Analysis For Swnt Growth On Shutter Sputtered Catalyst, Rebekah Arias

2022 MME Undergraduate Research Symposium

Carbon Nanotubes (CNTs) have been used in remarkable ways since their discovery in 1991 by Sumio Iijima. Properties such as high thermal conductivity, good mechanical strength, and electrical conductivity are what make CNTs attractive. Some of their applications include water filtration, vehicles, energy storage, and now there is great potential in the biomedical field for CNTs as composites in tissue engineering, therapeutics carrier across the blood-brain barrier, cancer treatment, and much more. The issue that comes with Single-Walled Nanotubes (SWNTs) however is Ostwald ripening of catalyst and low CNT production. It is difficult to control gas parameters for hydrogen and …

Cnt Metamaterial Fabrication 3d Printing Mask Process, Jose J. Rivero Iii

2022 MME Undergraduate Research Symposium

The demand for clean energy is rising with the global population. Renewable energy sources, such as solar, will play a key role in the years ahead. Solar energy has a key problem with energy storage as the energy produced during peak solar hours must be used immediately or stored. Carbon Nanotubes (CNTs) have unique electrostatic properties, similar to metals, capable of producing and storing electric energy in the form of a capacitor. The CNTs are to be arranged in a pattern using 3D printing to generate a Split Ring

Resonator (SRR) metamaterial. Past research has shown generating CNT SRR patterns …

3d Printing Of Lunar Regolith Based Ceramics Via The Dlp Method, Ricardo Vasquez

2022 MME Undergraduate Research Symposium

Ceramic parts generally have poor machinability due to their high hardness and high brittleness. Researchers and industries have overcome the difficulty of machining ceramics and have manufactured parts with intricate geometry by using pre-ceramic polymers in stereolithography (SLA) 3D printing and using slurries based on ceramic powder and photopolymer resin in digital light processing (DLP) 3D printing, among other methods. This presentation will discuss the processes involved in the 3D printing of ceramic and ceramic composite parts via the DLP technique. A vital step in ceramic 3D printing is to optimize the printing parameters for a specific slurry formulation in …

Fracture Strength Of Multi-Component Ultra-High Temperature Carbides, Gia Garino

2022 MME Undergraduate Research Symposium

Ultra-high temperature ceramics (UHTCs) have emerged as a promising material for next generation re-entry hypersonic vehicles due to high melting point (>3000 °C), and high mechanical properties and oxidation resistance. Yet none of the unary UHTCs can satisfy the whole gamut of demanding requirements for aerospace applications. Recently, the single-phase solid-solution formation in a multi-component ultra-high temperature ceramic (MC-UHTC) materials have gained interest due to their superior thermo-mechanical properties compared to conventional UHTCs. Herein, a systematic approach was used to fabricate binary (Ta, Nb)C, ternary (Ta, Nb, Hf)C, and quaternary (Ta, Nb, Hf, Ti)C UHTCs by gradual addition of …

Gopher Tortoise Seed Dispersal Monitoring, Bryan Torres Garcia

2022 MME Undergraduate Research Symposium

Gopher tortoises are native to Florida and vital to the ecosystem due to the underground boroughs they build, which provide shelter to other animals, and for their key role in seed dispersion. In order to improve our understanding of the role of gopher tortoises on biodiversity, we aim to investigate the digestive track of gopher tortoises. Data on seed dispersion distance and gut retention time are critical to effective and efficient endangered plant species conservation efforts. In a multidisciplinary project between Department of Earth and Environment, College and Engineering, and the Miami Zoo, we are fabricating an ingestible device to …

In-Operando Optical Observation/Visualization Of Lithium-Sulfur Battery Discharge Process, Ana G. Claus

2022 MME Undergraduate Research Symposium

Lithium−Sulfur (Li-S) batteries have attracted attention due to their high-energy density, 2500 Wh/𝑘𝑔𝑐𝑒𝑙𝑙 [1], and theoretical capacity of 1672 mAh/g-S [2]. In addition to that, sulfur abundance makes it a good candidate for rechargeable batteries. However, Li-S system has a few challenges that hinder its commercialization. Such as the insulating nature of the sulfur element, volume expansion, capacity fade due to intermittent polysulfide dissolution in the electrolyte and drop in capacity during the initial discharge cycles [3]. Herein, we have designed a Li-S in-operando optical observation cell, which allowed us to visualize the formation of higher to lower-order polysulfides as …

Development Of An Automated Platform For Sensing And Differentiating Vapor-Phase Btex Constituents, Jonathan Samuelson

USF Tampa Graduate Theses and Dissertations

Light aromatic hydrocarbons are an inevitable byproduct of fossil fuel extraction, refinement, distribution, and use. The four lightest and most prevalent of these are benzene, toluene, ethylbenzene, and xylene, which are known collectively as BTEX. In spite of their chemical similarity these species have markedly different effects on human health and substantially different concentrations are permitted by OSHA in workplaces and by the EPA in ambient air and groundwater. Real-time detection, identification, and quantification of these species is therefore of great importance wherever they see industrial use.This work represents the continuation and advancement of a line of research in which …

Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal

Articles

The increased environmental pollution has led to finding sustainable solutions for non-renewable plastic-based food packaging materials. Thus, the use of biomaterial-based packaging material has become an immense trend. This work aims at developing an antimicrobial biodegradable chitosanalginate bio-nano composite film with TiO2 nanoparticle (NPs) for food packaging applications. The film was developed by a solution casting method. The chemical, mechanical, thermal, barrier, antimicrobial, and biodegradable properties of the packaging films were evaluated. Packaging studies were performed for 15 days for cherry tomatoes. The designed packaging material had enhanced the mechanical properties with a significantly (p < 0.05) higher tensile strength of 15.76 folds and 2 fold higher elongation at break. The UV barrier properties increased by 88.6%, while the film transparency decreased by 87.23%. Molecular interaction of N-H covalent bonds was observed between alginate and chitosan together with TiO2 NPs. The developed bio-nano composite film showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene with a log reduction of 7.08, 7.28, 6.04 & 6.02 log CFU/ml respectively at 24 hours incubation period. The film was completely biodegraded and a weight loss of 89.06% was observed in bio-nanocomposite film during the 3 months. Shelf-life estimation of cherry tomato using developed packaging films showed an increase in the shelf-life up to 8 days with stable pH, total soluble solids, and weight with no bacterial growth when packaged with prepared film. Owing to their improved mechanical, UV barrier, antibacterial, and biodegradability, the prepared active bio-nano composite packaging films could be considered a potential candidate for fruit packaging.

Sodium Alginate, Nanoclay And Curcumin Based Food Packaging Material For Intelligent Food Packaging Applications, Kalpani Y. Perera, Máille Hopkins, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal

Articles

Bionanocomposite food packaging contains materials of biological origin which display high-performance activity when compared to biopolymers and are eco-friendly alternatives to conventional packaging materials. Intelligent packaging monitors the condition of the food or environment surrounding the food and communicates changes to the consumer. This study aimed to develop a bionanocomposite intelligent packaging material by utilising sodium alginate, nanoclay and curcumin. Sodium alginate (2 W/V% SA) film incorporated with 0.3 W/V% curcumin (Cur), glycerol, and nanoclay (NC) in various concentrations (0, 0.5, 1 and 2 W/V %) was prepared using the solvent casting method. The influences of nanoclay and curcumin on …

Adiabatic Shear Banding In Nickel And Nickel-Based Superalloys: A Review, Russell A. Rowe, Paul G. Allison, Anthony N. Palazotto, Keivan Davami

Faculty Publications

This review paper discusses the formation and propagation of adiabatic shear bands in nickel-based superalloys. The formation of adiabatic shear bands (ASBs) is a unique dynamic phenomenon that typically precedes catastrophic, unpredicted failure in many metals under impact or ballistic loading. ASBs are thin regions that undergo substantial plastic shear strain and material softening due to the thermo-mechanical instability induced by the competitive work hardening and thermal softening processes. Dynamic recrystallization of the material’s microstructure in the shear region can occur and encourages shear localization and the formation of ASBs. Phase transformations are also often seen in ASBs of ferrous …

Experimental Evidence That Shear Bands In Metallic Glasses Nucleate Like Cracks, Alan A. Long, Wendelin Wright, Xiaojun Gu, Anna Thackray, Mayisha Nakib, Jonathan T. Uhl, Karin A. Dahmen

Faculty Journal Articles

Highly time-resolved mechanical measurements, modeling, and simulations show that large shear bands in bulk metallic glasses nucleate in a manner similar to cracks. When small slips reach a nucleation size, the dynamics changes and the shear band rapidly grows to span the entire sample. Smaller nucleation sizes imply lower ductility. Ductility can be increased by increasing the nucleation size relative to the maximum (“cutoff”) shear band size at the upper edge of the power law scaling range of their size distribution. This can be achieved in three ways: (1) by increasing the nucleation size beyond this cutoff size of the …

Sculpting Charge In Graphene Through Patterned Strain, Dylan J. Balter, Jenna Smith

The Journal of Purdue Undergraduate Research

No abstract provided.

Processing Of Plastic Film From Potato Starch: Effect Of Drying Methods, Kourtney Collier, Samantha Goins, Austin Chirgwin, Isabelle Stanfield

The Journal of Purdue Undergraduate Research

Starch-based plastics are biodegradable, compostable compounds made of starch and plasticizers from natural sources. Their fabrication involves the starch-plasticizer reaction at 70–100°C followed by cooling and drying. Th e most common drying method is air drying (natural convection), which is effective but slow. Th e objective of this work is to study the effect of fast drying (forced convection) on the quality of the plastic film. Th is work compares the effects of drying conditions and drying rate on warpage, shrinkage rate, and presence of bubbles. Five drying methods are studied: (1) natural convection with uncovered petri dish, (2) natural …

Oxidation Of Hafnium Diboride—Silicon Carbide At 1500 °C In Air; Effect Of Compressive Stress, Anthony J. Degregoria, Marina B. Ruggles-Wrenn

Faculty Publications

The long-term oxidation behavior of HfB₂ and of HfB₂-20 vol.% SiC was studied. Test samples of each material were oxidized at 1500 °C in air using a box furnace. The exposure times were 0, 0.5, 1, 2, 3, 6, 9, 12, 15, 30, 45 and 90 h. Weight gain, oxide scale composition and oxide scale thickness were characterized for both materials. Crystal structure of the surface scales was analyzed using x-ray diffraction. Oxide scales were further characterized via scanning electron microscopy with energy dispersive spectroscopy analysis. For HfB₂ the oxide scale consists predominantly of porous HfO …

Optimizing Switching Of Non-Linear Properties With Hyperbolic Metamaterials, James A. Ethridge, John G. Jones, Manuel R. Ferdinandus, Michael J. Havrilla, Michael A. Marciniak

Faculty Publications

Hyperbolic metamaterials have been demonstrated to have special potential in their linear response, but the extent of their non-linear response has not been extensively modeled or measured. In this work, novel non-linear behavior of an ITO/SiO₂ layered hyperbolic metamaterial is modeled and experimentally confirmed, specifically a change in the sign of the non-linear absorption with intensity. This behavior is tunable and can be achieved with a simple one-dimensional layered design. Fabrication was performed with physical vapor deposition, and measurements were conducted using the Z-scan technique. Potential applications include tunable optical switches, optical limiters, and tunable components of laser sources.

Comparing Structure-Property Evolution For Pm-Hip And Forged Alloy 625 Irradiated With Neutrons To 1 Dpa, Yu Lu

Materials Science and Engineering Faculty Publications and Presentations

The nuclear power industry has growing interest in qualifying powder metallurgy with hot isostatic pressing (PM-HIP) to replace traditional alloy fabrication methods for reactor structural components. But there is little known about the response of PM-HIP alloys to reactor conditions. This study directly compares the response of PM-HIP to forged Ni-base Alloy 625 under neutron irradiation doses ∼0.5–1 displacements per atom (dpa) at temperatures ranging ∼321–385 °C. Post-irradiation examination involves microstructure characterization, ASTM E8 uniaxial tensile testing, and fractography. Up through 1 dpa, PM-HIP Alloy 625 appears more resistant to irradiation-induced cavity nucleation than its forged counterpart, and consequently experiences …

Synthesis And Assembly Of Polymer Materials At Interfaces, Xiaoshuang Wei

Doctoral Dissertations

The overarching goal of the thesis is to understand growth and assembly of polymer materials at interfaces. Chapter 2 and Chapter 3 study simultaneous polymer growth and assembly at fluid interfaces, where in-situ photopolymerization and vapor phase deposition were utilized to grow polymers, respectively. Chapter 4 leverages capillary condensation to pattern polymer growth at solid substrates.

Chapter 1 provides background information on polymer materials at interfaces, and vapor phase deposition method (initiated chemical vapor deposition, iCVD) to grow polymers. This chapter also reviews polymer thin film wetting, and colloidal assemblies at interfaces.

In Chapter 2, we demonstrate the preparation …

Explorer 14 Magnetron Sputterer (Pvd-05) Standard Operating Procedure, Mohsen Azadi, Jason Alexander Röhr

Standard Operating Procedures

Standard Operating Procedure for the Explorer 14 Magnetron Sputterer (PVD-05) located at the Quattrone Nanofabrication Facility within the Singh Center for Nanotechnology at the University of Pennsylvania