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Soft-Microrobotics: The Manipulation Of Alginate Artificial Cells, Samuel Sheckman 2019 Southern Methodist University

Soft-Microrobotics: The Manipulation Of Alginate Artificial Cells, Samuel Sheckman

Mechanical Engineering Research Theses and Dissertations

In this work, the approach to the manipulation of alginate artificial cell soft-microrobots, both individually and in swarms is shown. Fabrication of these artificial cells were completed through centrifugation, producing large volumes of artificial cells, encapsulated with superparamagnetic iron oxide nanoparticles; these artificial cells can be then externally stimulated by an applied magnetic field. The construction of a Permeant Magnet Stage (PMS) was produced to manipulate the artificial cells individually and in swarms. The stage functionalizes the permanent magnet in the 2D xy-plane. Once the PMS was completed, Parallel self-assembly (Object Particle Computation) using swarms of artificial cells in complex ...


Energy Conversion System For Travelers (Ecost), Thipok Bovornratanaraks 2018 Chulalongkorn University Demonstration Secondary School

Energy Conversion System For Travelers (Ecost), Thipok Bovornratanaraks

The International Student Science Fair 2018

We have innovated “The Energy Conversion System for Travelers” or the ECoST. With the fact that most travelers have wheeled cabin-bags, whilst walking, the wheels will rotate so why don’t we harvest electricity from this kinetic energy? We thus install our innovation, the ECoST, to the bag to generate electricity from the spinning wheels. The electricity is then kept in the storage unit and ready to charge your empty battery devices in an emergency case via a USB port. To make life easy, our ECoST was designed to replicate the power bank charging method; therefore, we can charge it ...


Feco2o4 As An Anode Material For Lithium Ion Batteries, Chelsea Wong 2018 National Junior College

Feco2o4 As An Anode Material For Lithium Ion Batteries, Chelsea Wong

The International Student Science Fair 2018

Lithium ion batteries (LIBs) are commonly found in many portable electronic appliances due to their ability to be rechargeable. Currently, commercial anodes in Li-ion batteries (graphite) have a theoretical capacity of around 372 mAh/g, while FeCo2O4 that will be investigated as the anode material has a theoretical capacity of 901.985mAh/g, more than double of the current commercial anode’s capacity. Earlier work done by Sharma et al also showed that FeCo2O4 has a very promising initial capacity of 827mAh/g. As such, the engineering goal is to produce a battery that will have a higher capacity than ...


Aftershocks In Slowly Compressed Bulk Metallic Glasses: Experiments And Theory, Louis W. McFaul, Wendelin Wright, Xiaojun Gu, Jonathan T. Uhl, Karin A. Dahmen 2018 University of Illinois at Urbana-Champaign

Aftershocks In Slowly Compressed Bulk Metallic Glasses: Experiments And Theory, Louis W. Mcfaul, Wendelin Wright, Xiaojun Gu, Jonathan T. Uhl, Karin A. Dahmen

Faculty Journal Articles

We observe two distinct interevent time patterns in the slip avalanches of compressed bulk metallic glasses (BMGs). Small slip avalanches cluster together in time, but large slip avalanches recur roughly periodically. We compare the timing patterns of BMG slip avalanches with timing patterns of earthquakes and with the predictions of a mean-field model. The time clustering of small avalanches is similar to the known time clustering of earthquake foreshocks and aftershocks.


Design And Characterization Of Polymer Nanocomposites For Engineering Applications, Joseph Richard Nalbach 2018 Rowan University

Design And Characterization Of Polymer Nanocomposites For Engineering Applications, Joseph Richard Nalbach

Theses and Dissertations

Polymer nanocomposites represent an area of materials that can yield useful properties not achievable in bulk materials. Not only can they have such properties but also they can be relatively easy to generate. With dwindling fossil fuels there is an increased need for both new methods to harvest energy and to transport the captured energy more effectively. Two separate nanocomposite materials are created to support this work with dramatically different properties, both to aid in energy efficiency. The first is an energy harvesting foam to fully utilize the structural deformability of such a material. A dissolvable sugar scaffold is combined ...


Chemically Modified Gellan Gum Hydrogels With Tunable Properties For Use As Tissue Engineering Scaffolds, Zihao Xu, Zhuqing Li, Shan Jiang, Kaitlin M. Bratlie 2018 Iowa State University

Chemically Modified Gellan Gum Hydrogels With Tunable Properties For Use As Tissue Engineering Scaffolds, Zihao Xu, Zhuqing Li, Shan Jiang, Kaitlin M. Bratlie

Chemical and Biological Engineering Publications

Gellan gum is a naturally occurring polymer that can cross-link in the presence of divalent cations to form biocompatible hydrogels. However, physically cross-linked gellan gum hydrogels lose their stability under physiological conditions, thus restricting the applications of these hydrogels in vivo. To improve the mechanical strength of the gels, we incorporated methacrylate into the gellan gum and chemically cross-linked the hydrogel through three polymerization methods: step growth through thiol–ene photoclick chemistry, chain-growth via photopolymerization, and mixed model in which both mechanisms were employed. Methacrylation was confirmed and quantified by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared ...


Modeling Recombination In Solar Cells, Paul Chery 2018 Macalester College

Modeling Recombination In Solar Cells, Paul Chery

Macalester Journal of Physics and Astronomy

Solar cells are a competitive alternative to nonrenewable energy sources such as fossil fuels. However, the efficiency of these devices is limited by photogenerated carrier recombination. We use a finite difference numerical model to study recombination phenomena in the absorber layer of solar cells including alternate recombination models and the effects of spatial distribution of recombination centers. We compare the effect of using the constant lifetime approximation for recombination to the full Shockley-Read-Hall expression in Silicon solar cells and find that the constant lifetime approximation holds for high defect densities but not for high photon flux densities. Finally, we simulate ...


Feco2o4 As An Anode Material For Lithium Ion Batteries, Chelsea Wong 2018 National Junior College

Feco2o4 As An Anode Material For Lithium Ion Batteries, Chelsea Wong

The International Student Science Fair 2018

Lithium ion batteries (LIBs) are commonly found in many portable electronic appliances due to their ability to be rechargeable. Currently, commercial anodes in Li-ion batteries (graphite) have a theoretical capacity of around 372 mAh/g, while FeCo2O4 that will be investigated as the anode material has a theoretical capacity of 901.985mAh/g, more than double of the current commercial anode’s capacity. Earlier work done by Sharma et al also showed that FeCo2O4 has a very promising initial capacity of 827mAh/g. As such, the engineering goal is to produce a battery that will have a higher capacity than ...


Microstructural Characterization Of Shear Transformation Zones And Modeling Indentation Size Effect In Amorphous Polymers, Leila Malekmotiei 2018 Louisiana State University

Microstructural Characterization Of Shear Transformation Zones And Modeling Indentation Size Effect In Amorphous Polymers, Leila Malekmotiei

LSU Doctoral Dissertations

The first aim of this work is developing a procedure for experimental and analytical characterization of nano-scale microstructures which mediate large scale deformation in amorphous polymers. Glassy polymers are extensively used as high impact resistant, low density, and clear materials in industries. Nevertheless, their response under severe loading conditions is yet to be appropriately unraveled. Due to the lack of long-range order in the microstructures of glassy solids, their plastic deformation is different from that in crystalline solids. Shear Transformation Zones (STZs) are believed to be the main plasticity carriers in amorphous solids and defined as the localized atomic or ...


Glucosamine From Hydrolysis Of 3d Printing Chitosan For Osteoarthritis Treatment, Ruj Dansriboon, Laphon Premcharoen 2018 Kamnoetvidya Science Academy

Glucosamine From Hydrolysis Of 3d Printing Chitosan For Osteoarthritis Treatment, Ruj Dansriboon, Laphon Premcharoen

The International Student Science Fair 2018

This project aims to introduce a new way for osteoarthritis treatment which is expected to increase in the future. Glucosamine is the main subject for a treatment, which can be derived by hydrolyzing chitosan. This project also includes extraction of chitosan from shrimp waste to make a worthy use of food waste from industry. In this project, 3D printer is applied to print chitosan gel since 3D printing is adjustable to form various shapes of the gel.

The research process begins with the extraction of chitosan from shrimp shells. For the next step, the percent of deacetylation of chitosan was ...


Sources Of Glass Transition Temperature Variation In Poly(Methyl Methacrylate)/Cellulose Composites, Elena Mamycheva 2018 The University of Western Ontario

Sources Of Glass Transition Temperature Variation In Poly(Methyl Methacrylate)/Cellulose Composites, Elena Mamycheva

Electronic Thesis and Dissertation Repository

Variation in glass transition temperature (Tg) measured by differential scanning calorimetry (DSC) is addressed, specifically for composites of poly(methyl methacrylate) (PMMA) and freeze-dried cellulose nanocrystals; mortar-and-pestle grinding use for creating solventless PMMA/cellulose nanocomposites is evaluated. Experimentally, solvent-containing and solventless PMMA and PMMA/cellulose composite samples (prepared using mortar-and-pestle grinding, melt-pressing, and acetone addition) were tested by DSC in hermetically-sealed pans using one of two maximum first heating scan temperatures; post-DSC samples were photographed. Mortar-and-pestle-ground cellulose was imaged by Field Emission Scanning Electron Microscopy (FE-SEM). Post-DSC samples had different shapes, some corresponding to greater increases in Tg from first ...


Effect Of Material Viscoelasticity On Frequency Tuning Of Dielectric Elastomer Membrane Resonators, Liyang Tian 2018 The University of Western Ontario

Effect Of Material Viscoelasticity On Frequency Tuning Of Dielectric Elastomer Membrane Resonators, Liyang Tian

Electronic Thesis and Dissertation Repository

Dielectric elastomers (DEs) capable of large voltage-induced deformation show promise for applications such as resonators and oscillators. However, the dynamic performance of such vibrational devices is not only strongly affected by the nonlinear electromechanical coupling and material hyperelasticity, but also significantly by the material viscoelasticity. The material viscoelasticity of DEs originates from the highly mobile polymer chains that constitute the polymer networks of the DE. Moreover, due to the multiple viscous polymer subnetworks, DEs possess multiple relaxation processes. Therefore, in order to predict the dynamic performance of DE-based devices, a theoretical model that accounts for the multiple relaxation processes is ...


Development Of Carbon Fiber-Modified Electrically Conductive Concrete For Implementation In Des Moines International Airport, Alireza Sassani, Halil Ceylan, Sunghwan Kim, Ali Arabzadeh, Peter C. Taylor, Kasthurirangan Gopalakrishnan 2018 Iowa State University

Development Of Carbon Fiber-Modified Electrically Conductive Concrete For Implementation In Des Moines International Airport, Alireza Sassani, Halil Ceylan, Sunghwan Kim, Ali Arabzadeh, Peter C. Taylor, Kasthurirangan Gopalakrishnan

Civil, Construction and Environmental Engineering Publications

This paper reports on the procedures of mix design preparation, production, placement, and performance evaluation of the first electrically conductive concrete (ECON) heated-pavement system (HPS) implemented at a U.S. airport. While ECON has drawn considerable attention as a paving material for multi-functional pavements, including HPS, the majority of ECON HPS applications and studies have been limited to laboratory scale or include materials/methods that do not conform to regulations enforced by airfield construction practices. Carbon fiber-reinforced ECON provides a promising prospective for application in airfield pavements. In this study, ECON mixtures were prepared in the laboratory using varying cementitious ...


Phase Change Materials For Thermal Management Of Kennedy Library Study Rooms, Colin J. Empey 2018 California Polytechnic State University, San Luis Obispo

Phase Change Materials For Thermal Management Of Kennedy Library Study Rooms, Colin J. Empey

Materials Engineering

The overall purpose of this study was to find a phase change material (PCM) or a combination of PCMs as a thermal management solution for the fifth-floor study rooms in Kennedy Library. First and foremost, the PCM must take in heat to change phase. A PCM would be a better candidate the more heat it needs to change phase. To quantify this, the team utilized a DSC to find how much energy each candidate PCM required to change phase. Coconut oil, palm oil, and white chocolate were found to have the best ability to absorb heat. Secondly, the PCM should ...


Temper Response Of A Vanadium Microalloy Steel, Bradley W. Hostetler 2018 California Polytechnic State University, San Luis Obispo

Temper Response Of A Vanadium Microalloy Steel, Bradley W. Hostetler

Materials Engineering

This investigation details the effect of a quench-and-temper processing treatment on the mechanical properties of a microalloy steel being considered for use as a pipeline flange. Microalloy steels are normally processed via Thermo-Mechanically Controlled Processing (TMCP) due to the increased strength from ferrite grain refinement; however, the geometry of a pipeline flange requires post processing beyond TMCP which diminishes the strengthening effect provided by TMCP. The purpose of this research project is to determine the mechanical properties produced when a vanadium microalloy steel is quenched and tempered. The two major considerations are the effect of tempering time on properties and ...


Development Of Test Methods For Measuring Fiber Misalignment And Warping In Honeycomb-Core Composite Panels, Wyatt Taylor, Haripriya Nilakantan 2018 California Polytechnic State University, San Luis Obispo

Development Of Test Methods For Measuring Fiber Misalignment And Warping In Honeycomb-Core Composite Panels, Wyatt Taylor, Haripriya Nilakantan

Materials Engineering

Zodiac Aerospace manufactures honeycomb-core composite panels to be used in aircraft cabin interior components. During the manufacturing process, some panels become warped such that they cannot be used for their designated aircraft cabin components. As a result, these panels are scrapped because they cannot be recycled. About 44 to 90% of panels become warped during manufacturing. Warping is caused by many factors, including layer misalignment, processing parameters such as temperature and pressure gradients, and fiber misalignment in the prepregs. Currently, Zodiac does not have any data on the effect of fiber misalignment on panel warpage, so a testing protocol was ...


Investigation Of Narloy-Z Yield Strength In Response To Changes In Ingot Processing And Heat Treatment, Stanley C. Goto, Sarah E. Wattenberg 2018 California Polytechnic State University, San Luis Obispo

Investigation Of Narloy-Z Yield Strength In Response To Changes In Ingot Processing And Heat Treatment, Stanley C. Goto, Sarah E. Wattenberg

Materials Engineering

This study investigates the effect of cooling rate on the yield strength of NARloy-Z. NARloy-Z is a copper-based alloy with 3 wt.% silver and 0.5 wt.% zirconium. The types of NARloy-Z were classified by the ingot processing (old or new) and the material lot (old or new). There were three variations of NARloy-Z in this study: old processing and material (Old/Old); old processing and new material (Old/New); and new processing and material (New/New). NARloy-Z undergoes a braze thermal cycle and age (BTCA) heat treatment for its application, and a single cooling rate within the BTCA was ...


Anomalous 304 Stainless Steel Mechanical Properties In Medical Guide Wires, Andrew Joseph Freeman 2018 Cal Poly San Luis Obispo Materials Engineering Department

Anomalous 304 Stainless Steel Mechanical Properties In Medical Guide Wires, Andrew Joseph Freeman

Materials Engineering

Stainless steel medical guide wire cores, processed by Abbott Vascular, are returning anomalous mechanical properties upon strain hardening and heat treatment. As theory dictates, mechanical strength properties increase with strain hardening, and decrease with an annealing treatment. The opposite response is being observed. This is counter intuitive to fundamental materials knowledge, and a perfect materials engineering paradox. This project was designed to characterize these behaviors, and attempt to determine causation. To accomplish this, tensile testing of all processing steps mapped the mechanical property evolution of the wire. Published literature research revealed the potential of nitrogen and chromium solid state diffusion ...


Effects Of Head Formation And Heat Treatment On The Mechanical Properties Of Connecting Rod Bolts, Matthew R. Lauretta, Caleb A. Leavitt 2018 California Polytechnic State University, San Luis Obispo

Effects Of Head Formation And Heat Treatment On The Mechanical Properties Of Connecting Rod Bolts, Matthew R. Lauretta, Caleb A. Leavitt

Materials Engineering

Oliver Racing Parts (ORP; Charlevoix, Michigan) is looking to optimize their manufacturing process for high-strength connecting rod bolts. A high yield strength is desired for the bolts because deformation would result in catastrophic engine failure. The bolts were made of H11, a chromium hot-work tool steel; and MLX17, a precipitation hardenable stainless steel. Tensile testing was performed to determine the tensile and yield strengths of the bolts. Fracture surfaces were imaged via scanning electron microscopy to characterize the failure modes. To observe the effects of bolt heading on microstructure and bolt strength, two batches of MLX17 were prepared; one batch ...


Solar Cell Potential Induced Degradation Sensor, Luc Alexandre Tousignant 2018 California Polytechnic State University, San Luis Obispo

Solar Cell Potential Induced Degradation Sensor, Luc Alexandre Tousignant

Materials Engineering

It is important to maintain Photovoltaic (PV) cells and protect them from damage mechanisms like Potential Induced Degradation (PID), which can contribute to shorter lifespans and lower efficiencies. Current leakage through cell encapsulation can cause charge migration in PV cells that reduces the maximum quantum efficiency, which is the cause of PID. An experiment was setup to determine the feasibility of a non-silicon sensor able to produce similar leakage behavior to traditional PV cells under recorded humidity conditions. Thin sheet metals were encapsulated in EVA, a common PV encapsulant polymer, and mounted in aluminum framing. Three sensors, along with a ...


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