Materials Science and Engineering Commons^™

Photopolymerization Synthesis Of Magnetic Nanoparticle Embedded Nanogels For Targeted Biotherapeutic Delivery, Daniel Jonwal Denmark

USF Tampa Graduate Theses and Dissertations

Conventional therapeutic techniques treat the patient by delivering a biotherapeutic to the entire body rather than the target tissue. In the case of chemotherapy, the biotherapeutic is a drug that kills healthy and diseased cells indiscriminately which can lead to undesirable side effects. With targeted delivery, biotherapeutics can be delivered directly to the diseased tissue significantly reducing exposure to otherwise healthy tissue. Typical composite delivery devices are minimally composed of a stimuli responsive polymer, such as poly(N-isopropylacrylamide), allowing for triggered release when heated beyond approximately 32 °C, and magnetic nanoparticles which enable targeting as well as provide a mechanism for …

Magnetic Behavior And Spin-Lattice Coupling In Cleavable, Van Der Waals Layered Crcl3 Crystals, Michael Mcguire, Genevieve Clark, Santosh Kc, W. Chance, Gerald Jellison, Valentino Cooper, Xiaodong Xu, Brian Sales

Faculty Publications

CrCl3 is a layered insulator that undergoes a crystallographic phase transition below room temperature and orders antiferromagnetically at low temperature. Weak van der Waals bonding between the layers and ferromagnetic in-plane magnetic order make it a promising material for obtaining atomically thin magnets and creating van der Waals heterostructures. In this work we have grown crystals of CrCl3, revisited the structural and thermodynamic properties of the bulk material, and explored mechanical exfoliation of the crystals. We find two distinct anomalies in the heat capacity at 14 and 17 K confirming that the magnetic order develops in two stages on cooling, …

Computational Study Of Mos2/Hfo2 Defective Interfaces For Nanometer-Scale Electronics, Santosh Kc, Roberto Longo, Robert Wallace, Kyeongjae Cho

Faculty Publications

Atomic structures and electronic properties of MoS2/HfO2 defective interfaces are investigated extensively for future field-effect transistor device applications. To mimic the atomic layer deposition growth under ambient conditions, the impact of interfacial oxygen concentration on the MoS2/HfO2 interface electronic structure is examined. Then, the effect on band offsets (BOs) and the thermodynamic stability of those interfaces is investigated and compared with available relevant experimental data. Our results show that the BOs can be modified up to 2 eV by tuning the oxygen content through, for example, the relative partial pressure. Interfaces with hydrogen impurities as well as various structural disorders …

Enhanced Visible Light Photocatalytic Remediation Of Organics In Water Using Zinc Oxide And Titanium Oxide Nanostructures, Srikanth Gunti

USF Tampa Graduate Theses and Dissertations

The techniques mostly used to decontaminate air as well as water pollutants have drawbacks in terms of higher costs, require secondary treatment, and some methods are very slow. So, emphasis has been given to water though the use of photocatalysts, which break organic pollutants to water and carbon dioxide and leave no trace of by-products at the end. Photocatalytic remediation aligns with the waste and wastewater industries’ zero waste schemes with lower cost, eco-friendly and sustainable treatment technology. The commonly used photocatalysts such as titanium oxide (TiO₂), zinc oxide (ZnO), tungsten oxide (WO₃) have band gap …

Characterization Of Slm Printed 316l Stainless Steel And Investigation Of Microlattice Geometry, Finley H. Marbury

Materials Engineering

The goal of this project was firstly to characterize Cal Poly’s SLM printed 316L stainless steel. SEM analysis showed Cal Poly’s as-printed 316L material to have a cellular dendritic microstructure containing mostly austenite and a small amount of δ-ferrite. After being heat treated to eliminate warp, its yeild and ultimate tensile strength were on par with the literature, however higher modulus and lower elongation were observed. XRD analysis confirmed residual stresses in the material, and that grains are preferentially oriented in both heat treated and non heat treated samples. The amount of porosity in the material was found to be …

Characterization Of The 15-5 Stainless Steel Electric Discharge Machining Recast Layer, Julian R. Lohser, Rhys W. Gilmore

Materials Engineering

Electric discharge machining (EDM) is a non-conventional machining process that is used for tough, hard materials or materials that require no tool force. Wire EDM produces a recast layer and heat-affected zone as a result of rapid melting and quenching at the surface of the cut. A secondary machining operation has been required to remove this layer. Previous estimates of the depth of the recast layer are likely too conservative due to improvements in the technology; therefore, the goal of this study is to characterize and more accurately investigate the size of the layer. Two EDM machine parameters, voltage and …

Inkjet Printing Of Nano-Silver Conductive Ink On Pet Substrate, Skyler Jiang

Materials Engineering

Printing of conductive ink traditionally uses copper-based ink and was used on high temperature metal substrates due to the high curing and sintering temperature of copper. In this experiment, however, Metalon JS-B25P nano-silver conductive ink was printed using an Epson Stylus C88+ inkjet printer on polyethylene terephthalate (PET) based Novele printing media made for low temperature applications. With silver’s lower sintering temperature, the nano-silver particles in this ink are desired to be able to sinter at a low enough temperature to be used on the PET substrate. The printed ink traces were cured with a temperature-controlled hotplate at 100℃, 120℃, …

The Relationship Between Structural Parameters And Mechanical Properties Of Cactus Spines, Jorge Armando Martinez, Pamela Liz Szeto, Theresa Mae Stewart

Materials Engineering

Considering an increasing interest in renewable, biodegradable resources that exhibit excellent mechanical properties, 24 species of cactus spines were investigated using three-point bend testing, X-ray diffraction (XRD) for structural parameters, and scanning electron microscopy (SEM) to analyze fracture surfaces. Additionally, a density of about 1.3 g/cm3 was measured for each spine utilizing the displacement method, closely matching existing data from literature. The flexural modulus varied greatly between species, ranging from 1.22 GPa (Echinocactus polycephalus) to 43.58 GPa (Stenocereus thurberi). In addition, flexural strength and strain to failure was also measured for each spine. XRD analysis of …

Selective Depolymerization Of Industrial Hemp And Its Effects On Thermal Resistivity, Tanner J. Jolly

Materials Engineering

There is a growing shift within the construction materials industry towards green and sustainable building products. Spending in this area has increased 5 fold since 2011 to a total revenue of $70 billion. An area of particular interest has been aimed at replacing fiberglass batt insulation with cellulose. Cellulose is the most abundant polymer on earth, and has potential to replace petroleum derived insulations. This project explores the potential of selectively isolating cellulose by depolymerizing the support structures found in lignocellulosic materials – specifically lignin and hemicellulose. The current focus is on isolating cellulose from Cannibas sativa, but more …

Tensile Properties Of High-Strength Connecting Rod Bolts, Leland K. Lam

Materials Engineering

Oliver Racing Parts (ORP) is looking to optimize the manufacturing process for high-strength connecting rod bolts. A high yield strength is desired for the bolts because deformation would result in a loss of engine performance. A high tensile strength is also necessary to prevent catastrophic failure if deformation occurs. A high ductility as a proxy for toughness is attractive for resisting crack nucleation and growth during cyclic loading. Bolts were made of MP35N, a nickel-cobalt multiphase alloy; MLX-17, a precipitation hardenable stainless steel; 8740, a low alloy steel; and H11, a chromium hot-work tool steel. The temperature of the most …

Straightening Of Investment Casting Ni-Based Superalloys, Silvia Squillaci, Janessa Cabrera

Materials Engineering

Samples belonging to four different designs of afterburner flaps, available in the as-cast, solutionized and aged conditions, underwent 4-point bend testing to fracture to investigate straightening. The average maximum load values of the second design samples in the as-cast, solutionized and aged conditions were respectively 33 kN, 29 kN and 27 kN. Regarding the fourth design samples, the average maximum load for the as-cast, solutionized and aged conditions were respectively 23 kN, 28 kN, and 25 kN. The other parameter measured during testing was the maximum extension at fracture. All as-cast samples belonging to the second design fractured at values …

Mechanical Testing Protocol For Characterizing Composite Lamina Pre-Pregs, Kenneth Blain Ainslie, Joshua Gustav Brinkmann

Materials Engineering

Zodiac Aerospace currently employs finite element analysis (FEA) computer models to predict the material behavior of its composite products. The objective of this project was to develop a testing protocol for obtaining detailed material property data to use in these FEA models. With accurate material data, FEA models can reduce the need for expensive physical testing and achieve timely troubleshooting when testing complex components. The specific material characterized in this project was an 8-satin weave fiberglass phenolic pre-preg used as the facesheet material in many of Zodiac’s sandwich panel composites. The developed testing protocol involved mechanical testing of lamina and …

Comparison Of Intrusive And Non-Intrusive Methods For Corrosion Monitoring Of Fuel Processing Systems, Armando Jacob Espinoza, Thomas Conner Field

Materials Engineering

This presentation contains an assessment of the best overall corrosion monitoring device, intrusive or non-intrusive, for use in the petrochemical industry. Corrosion in the petrochemical industry is a large issue because it causes a deterioration of pipe integrity in fuel processing systems. A reduction of pipe wall integrity due to corrosion could result in a leak or an explosion of fuel processing lines since those systems function at high pressures. The use of corrosion monitoring systems in the petrochemical industry helps to detect early signs of corrosion prior to failure so that proper maintenance can be performed to prevent catastrophe. …

Investigation Of A Method To Determine Mechanical Properties Of Integral Composite Hinges For Application In Foldable Skis, Jada Evers, Kathryn Johnson

Materials Engineering

No abstract provided.

Predicting Service Life Of 347 Stainless Steel Pipes By Carburization Rate Measurement, Tyler L. Sura

Materials Engineering

Chevron Corporation and other refiners face challenges predicting the service life of piping in coker furnaces. This is largely due to a build up coke on a single surface of the piping. This coke build up results in carbon penetration into the surface of the 347 stainless steel used for the pipes. Carbon penetration can lead to degradation of the surface and ultimately, the failure of the pipe. Current modeling software has difficulty predicting the influence of sulfur on the carbon penetration rate. This study aims to provide a baseline for further study into the subject. The carbon penetration rate …

Development Of Low Cost Braze Alloys For Aerospace Applications, Alyssa M. Elliott, Sandy Babich, Blake Whitmee

Materials Engineering

Non-precious metal braze alloys can help lower the cost of brazing, which is a commonly-used joining process in the aerospace industry. A-286, a stainless steel superalloy, and Inconel© 718, a nickel-based superalloy, are both commonly used alloys at Aerojet Rocketdyne. Both alloys were brazed into butt joints using nickel-based braze alloys: AMS 4776, 4777, and 4778. The brazed samples were machined into a modified version of the ASTM E8 subsize specimen samples and tensile tested to compare the strength and calculated elongation of the brazed samples to the base metals’ properties. All of the brazed samples fractured at the joint, …

Qualification Of Blue Laser Cutting Tool And Design Of Test Procedure For Determining Cutting Parameters, Gaia Righi

Materials Engineering

No abstract provided.

Invariant-Based Method For Improving Efficiency Of Mechanical Testing In Aerospace Certification Of Carbon Fiber-Epoxy Composites, Alyssa Rina Gruezo, Erika Gabrielle Hansen

Materials Engineering

The current challenge with qualification of carbon fiber composites in the aerospace industry would be the low efficiency of testing hundreds of samples. The Trace Theory strives to streamline the qualification process by utilizing a material’s Trace to predict properties of composites using Excel programs and basis data. To test this theory, predicted properties from the program, QuickLam, were compared to experimental data. Unidirectional 0° (T1), unidirectional 90° (T2), quasi-isotropic (T3), and hard quasi-isotropic (T4) laminates were made using HexTowR carbon fiber and TC250 resin provided by TenCate Advanced Composites. Tensile and compression tests were done according to ASTM D3039 …

Reliability Test Fixture For Flexible Hybrid Electronics, Julia Akiko Roche, Maya Francesca Zumel Manzano, Paul Alfred Swartz

Mechanical Engineering

During the 2016-2017 school year, the Cal Poly NextFlex Group, in conjuncture with the Cal Poly Industrial and Manufacturing Engineering Department, was comprised of professors, undergraduate students, and graduate students all working towards the manufacturing of flexible hybrid electronics (FHEs). FHEs, which are comprised of a flexible plastic substrate (thermoplastic polyurethane), screen-printed silver ink, and a thin silicon wafer, have a wide range of potential applications. At the time of this project, FHEs and other flexible electronics did not have a set of test standards to characterize their mechanical and electrical properties. The Cal Poly NextFlex Group recruited three Cal …

The Modification Of A Curtain Coating Formulation: A Study Of Rheology And Surface Tension, And Their Effect On Pitting, Samantha Leigh Schoenfelder

Masters Theses

When an undisclosed recycled fiber mill installed a “two-slotted” curtain coater to replace their air knife coater, a prominent defect arose known as “pitting,” which is also called pinholing or cratering. Pitting occurs when the coating of the sheet has small holes that mar its surface, which, when clustered together or larger in size, can cause print breakup during the printing process.

Through research, pitting is known to be caused by a boundary layer of air that gets laterally pulled in between the coating and board during their initial contact. Thus, rheological properties and the surface tension of the curtain …

Fate Of Conductive Ink Pigments During Recycling And Landfill Deposition Of Paper-Based Printed Electronics, James Edward Atkinson

Dissertations

Printed electronics (PE) are being developed as an alternative to traditional electronics, due to the more efficient use of materials and lower cost of production. The overall goal of this study was to understand how metallic pigments in conductive inks in PE are partitioned during landfill disposal and paper recycling conditions. The purpose is to assess the potential environmental impacts of PE landfilling in terms of metal leaching and to help develop new strategies for sequestering metallic ink components while paper-based PE are subjected to conventional paper recycling methods. The objective of this research is to study the fate of …

Mitigation Of Corrosion Under Insulation (Cui) Of Carbon Steel Of Different Insulating Materials: A Literature Review And Testing Analysis, Michael Alexander Lowes

Materials Engineering

Equipment often found in refineries may be enveloped in insulation and weathering jackets to maintain internal processing temperatures. In many cases moisture from the environment will penetrate the weathering jacket and infiltrate the insulation, leaching corrosive ions to the surface of metal equipment, effectively creating a corrosion cell. The goal of this project is to investigate different insulating materials for their ability to inhibit corrosion under insulation (CUI). The inhibiting mechanism utilizes water ingress that leaches ions from the insulator to bond with the surface metal and create a passive layer, inhibiting any further corrosion. This study will follow ASTM …

Preliminary Investigations Into Selective Laser Melting, David Takeo Otsu

Master's Theses

Selective laser melting is a promising metallic additive manufacturing process with many potential applications in a variety of industries. Through a gracious donation made by Lawrence Livermore National Laboratory, California Polytechnic State University received and installed an SLM 125 HL selective laser melting machine in February 2017. As part of the initial setup effort, a preliminary machine verification study was conducted to evaluate the general print quality of the machine with default parameter settings. Coincidentally, the as-printed microstructure of SLM components was evaluated through nil strength fracture surface examination, an alternative to conventional polish-and-etch metallography. A diverse set of components …

Kinked Tensile Behavior Of Cold Worked Nitinol, Grant R. Caraway, Samuel J. Canovas

Materials Engineering

To characterize the decrease in ductility caused by an induced stress concentration as a function of various levels of cold work and heat treatment, Nitinol medical guide wires with a .004″ diameter were tested using both a standard, straight tensile test and a modified, bent tensile test. The ratio of the two break loads (bent:straight) for identically processed samples was used as a proxy for measuring the ductility of the guide wires: the higher the ratio, the more ductile the sample. The average break load ratio as a function of increased cold work, decreased from 1.27 to 0.91 for the …

Effect Of Composition And Build Direction On Additively Manufactured Hastelloy X Alloys, Justin A. Spitzer, Jeffrey T. Schloetter, Sarah Zerga

Materials Engineering

Microcracking has caused premature failure and reduction in properties in additively manufactured (AM) Hastelloy X. The purpose of this research is to meet or exceed the mechanical properties of wrought Hastelloy X by modifying the composition and build direction of Hastelloy X manufactured using Direct Metal Deposition (DMD). Tensile testing, scanning electron microscopy (SEM), and metallography were performed on the samples. ANOVA was used to analyze the dependence that the properties had on build direction and composition. The nominal composition wrought samples had a yield strength of 310.1 MPa and a 60.79% Elongation. Alloy P60-X18 in a horizontal build had …

Mini High Temperature Test Unit Final Design Report, Kevin Liu, Juan P. Castillo

Mechanical Engineering

Lawrence Livermore National Laboratory has invested considerable effort to develop new standard for nuclear grade HEPA filters that can withstand high temperatures along with methods to optimally test not only the experimental filter media, but also new frame seals and media binders. Therefore, LLNL in collaboration with Cal Poly has designed and built a Mini High Temperature Testing Unit (MHTTU) to recreate conditions observed during a fire and to test different materials in an effective, inexpensive, regulated and reliable method. The existing prototype was unable to achieve the ideal testing conditions of 1000°F air at the low flow rates of …

Bear Minimum: Ultralight Composite Bear Canister, Rama B. Adajian, Adam C. Eisenbarth

Mechanical Engineering

The ultralight backpacking community needs a strong, easy to use, safe bear canister that is lighter than current market products for trekking in the backcountry. A full design of the lid for the bear canister is to be completed. This includes the locking mechanism to ensure it is bear proof, the interface between the lid and the canister, and the structure of the lid so it passes the strength and weight specifications. The lid, along with the already designed canister body, is to be manufactured with formal documentation. The lid will initially be tested separately and then with the canister …

The Magnetic, Electrical And Structural Properties Of Copper-Permalloy Alloys, Makram A. Qader, A. Vishina, Lei Yu, Cougar Garcia, Rakesh K. Singh, Nicholas D. Rizzo, Mengchu Huang, Ralph Chamberlin, Kirill Belashchenko, Mark Van Schilfgaarde, N. Newman

Kirill Belashchenko Publications

Copper-permalloy [Cu_1–x(Ni₈₀Fe₂₀)_x] alloy films were deposited by co-sputtering and their chemical, structural, magnetic, and electrical properties were characterized. These films are found to have favorable weak ferromagnetic properties for low temperature magnetoelectronic applications. Our results show that by varying the composition, the saturation magnetization (M_s) can be tuned from 700 emu/cm³ to 0 and the Curie temperature (T_c), can be adjusted from 900 K to 0 K. The M_s and T_c are found to scale linearly between x = 25% and 100%. Electronic structure calculations …

Memorizing Chromic Response To Pressure, Maulik Kiritkumar Padh

Theses

Almost all appliances are prone to mechanical stress in one form or the other. An increasing dependence on machines in daily life calls for a need to increase their maintenance quality. Various materials, methods and configurations to observe mechanical pressure have been devised and this paper discusses one such technique. The use of gold nanoparticles in its one dimensional array causes plasmonic coupling between the nanoparticles, which when disrupted creates a plasmonic shift in its assembly. Such a film, when casted on a polymer with a known elastic limit, causes deformation by an application of stress. This forces the film …

Corrosion Studies Of Stainless Steel Blades, Dhruv S. Kothari

Theses

Corrosion is a subject of interest to interdisciplinary research communities that includes fields of materials science, chemistry, physics, metallurgy and chemical engineering. In order to understand the mechanisms of corrosion and the function of corrosion inhibitors, the reactions at the interfaces between the corrosive electrolyte and a steel surface, particularly at the initial stages of the corrosion process, need to be described. Naturally, these reactions are strongly affected by the nature and properties of the steel surfaces. It is however seen that the majority of recent corrosion and corrosion-inhibition investigations are limited to electrochemical testing, with ex situ analysis of …