Synthesis Of Graphene Nanosheets Through Spontaneous Sodiation Process, 2018 Iowa State University
Synthesis Of Graphene Nanosheets Through Spontaneous Sodiation Process, Deepak-George Thomas, Emrah Kavak, Niloofar Hashemi, Reza Montazami, Nicole N. Hashemi
Mechanical Engineering Publications
Graphene is one of the emerging materials in the nanotechnology industry due to its potential applications in diverse areas. We report the fabrication of graphene nanosheets by spontaneous electrochemical reaction using solvated ion intercalation into graphite. The current literature focuses on the fabrication of graphene using lithium metal. Our procedure uses sodium metal, which results in a reduction of costs. Using various characterization techniques, we confirmed the fabrication of graphene nanosheets. We obtained an intensity ratio (ID/IG) of 0.32 using Raman spectroscopy, interlayer spacing of 0.39 nm and our XPS results indicate that our fabricated compound is ...
Design For Maintainability In Developing Communities—A Case Study On The Uros Islands, 2018 Brigham Young University
Design For Maintainability In Developing Communities—A Case Study On The Uros Islands, Thomas Barlow
Undergraduate Honors Theses
Designing products for developing communities has exposed many of the underlying assumptions that engineers from developed nations have during the design process. There has been much written about these underlying assumptions in order to create a better framework for designing for developing communities. One unexplored, yet important area is the universality of common maintainability principles used in developed countries when designing products used in developing communities. Such principles include: simplicity, diagnosability, standardization of parts, modular subassemblies, minimizing assembly and disassembly parts, labeling components, increased life of moving parts, manuals, and simplifying tools needed for repairs –. The purpose of ...
Microstructural Characterization Of Shear Transformation Zones And Modeling Indentation Size Effect In Amorphous Polymers, 2018 Louisiana State University and Agricultural and Mechanical College
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 ...
Experimental, Analytical, And Numerical Evaluation Of The Mechanical Properties Of The Brain Tissue, 2018 Louisiana State University and Agricultural and Mechanical College
Experimental, Analytical, And Numerical Evaluation Of The Mechanical Properties Of The Brain Tissue, Aref Samadidooki
LSU Doctoral Dissertations
A true understanding of the mechanisms behind most of the brain diseases is still out of reach. For several years, the interest of scientists has been focused on the genetic and biological causes, however, recent studies unraveled the importance of the biomechanics of the brain growth, folding, impact resistance, and deformation on its pathological conditions. While, a wide range of different methods have been used for characterization of the mechanical properties of the brain at the tissue level, the obtained results from different studies are extremely scattered and sometimes in contrast to one another. Since the brain tissue is extremely ...
Effect Of Material Viscoelasticity On Frequency Tuning Of Dielectric Elastomer Membrane Resonators, 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 ...
Design Of A Robotic Cownose Ray, 2018 Union College
Design Of A Robotic Cownose Ray, Mark Marzotto
Nature often inspires advances in science and technology and a promising example of this is mimicking locomotion of underwater animals. The main ways in which manmade aquatic vehicles propel themselves are water jets and propellers, which are inconsistent with how underwater animals swim. The cownose ray displays very efficient thrust with low frequency strokes by using a combination of oscillations and undulations with its pectoral fins. The goal of this paper is to mechanically replicate the actual fin motion of the cownose ray in order to capture these attractive features. The design will account for both the oscillations by designing ...
Prove Endurance Car Front Suspension, 2018 Cal Poly SLO
Prove Endurance Car Front Suspension, Lauren A. Williams, Logan Simon, Justine G. Kwan
This document details the collaborative Mechanical Engineering Senior Project with Cal Poly PROVE Lab on PROVE Lab’s Project 2; an electric vehicle designed to travel 1000 miles on a single charge. Logan Simon, Justine Kwan, and Lauren Williams are given the challenge of designing an innovative proof of concept front suspension suspension for this vehicle.
After detailed research of new suspension systems, it was determined that the innovative nature could be in the form of unique manufacturing methods, materials use, or mechanical design. At this point in time, this vehicle is a purely conceptual design with no concrete requirements ...
Beach Wheelchair Attachment, 2018 California Polytechnic State University
Beach Wheelchair Attachment, Abbey Jo Scholle, Jackson Dallas Wiley, Jackson Cole
This document includes the problem that is under scrutiny, the background research towards finding a solution, the objectives, scope of the project, the planned overall design process, the preliminary design we have produced and analyzed, the critical design we have manufactured, the testing and results, and the final assessment of the produced design. The problem is lack of easy access and movement for wheelchair users on the beach. Other solutions and designs have been logged under background research. With this information, the scope of work was designed to meet all the needs specified and describe how the specifications will be ...
Theoretical And Experimental Investigation Of Forward Spatter Of Blood From A Gunshot, 2018 University of Illinois at Chicago
Theoretical And Experimental Investigation Of Forward Spatter Of Blood From A Gunshot, P. M. Comiskey, A. L. Yarin, Daniel Attinger
Mechanical Engineering Publications
A theoretical model predicting forward blood spatter patterns resulting from a round nose bullet gunshot wound is proposed. The chaotic disintegration of a blood layer located ahead and aside of the bullet is considered in the framework of percolation theory. The size distribution of blood drops is determined, which allows for the prediction of a blood spatter cloud being ejected from the rear side of the target where the bullet exits. Then, droplet trajectories are numerically predicted accounting for gravity and air drag, which is affected by the collective aerodynamic interaction of drops through air. The model predicts the number ...
Blunt And Ballistic Impacts On Human Head Models: An Analytical And Numerical Study, 2018 Southern Methodist University
Blunt And Ballistic Impacts On Human Head Models: An Analytical And Numerical Study, Yongqiang Li
Mechanical Engineering Research Theses and Dissertations
Head injuries, as a leading cause of death, have become a major health care issue for civilians and soldiers. There has been an urgent need to understand mechanisms of such injuries. The objective of this dissertation research is to study some head injuries and related mechanisms using analytical and computational models.
In Chapter 2, a new analytical (non-linear) model for the impact of a solid sphere on a fluid-filled spherical shell is developed by including the stress wave propagation effect in addition to the Hertzian contact deformations and the shell membrane and bending actions. A simplified (linearized) model incorporating the ...
Soft-Microrobotics: The Manipulation Of Alginate Artificial Cells, 2018 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 ...
Modeling Of Swimming Cells From Nano-Scale To Micro-Scale, 2018 Washinton University in St. Louis
Modeling Of Swimming Cells From Nano-Scale To Micro-Scale, Yicheng Zhao
Engineering and Applied Science Theses & Dissertations
Certain human genetic diseases -- primary ciliary dyskinesia, infertility, and hydrocephalus -- are characterized by changes in beat frequency and waveform of cilia and flagella. Chlamydomonas reinhardtii, which is a single-cell green alga about ten micrometers in diameter that swims with two flagella, serves as an excellent biological model because its flagella share the same structure and genetic background as mammalian cilia and flagella. This study uses the finite element method to investigate the behavior of C. reinhardtii swimming from nano-scale to micro-scale. At the device-level, micro-scale modeling indicates that well-designed acoustic microfluidic devices can be used to trap groups of C ...
Digital Enhancement Of Analog Measurement Systems For Temperature Compensation Of Strain Gages, 2018 University of Texas at Tyler
Digital Enhancement Of Analog Measurement Systems For Temperature Compensation Of Strain Gages, Islombek Karimov
Electrical Engineering Theses
Generally known temperature compensation techniques for strain gages (like the use of a dummy gage or the implementation of half- and full-bridge configurations) are not applicable to all strain-measurement situations and cannot fully compensate for all sources of error. Digital Enhancement of Analog Measurement Systems presents a universal method of corrections for these effects in which temperature is measured independently of other variables and ex post facto corrections are computed and applied to digitized readings of the analog measurement system.
A single, linear-pattern strain gage, self-temperature-compensated for steel 1018, has been utilized in a quarter-bridge to measure tensile strain in ...
A High-Magnification Uv Lens For High-Temperature Optical Strain Measurements, 2018 Utah State University
A High-Magnification Uv Lens For High-Temperature Optical Strain Measurements, Robert S. Hansen
All Graduate Plan B and other Reports
Digital Image Correlation (DIC) is an experimental method used to produce full-field strain maps of specimens undergoing deformation. In this measurement, images of a specimen are taken before and after mechanical and thermal loading, then software is used to track deformation and compute strains. DIC has been recently adapted for high-temperature tests by using ultraviolet (UV) range cameras, lenses, and filters to produce the images.
Application of DIC to small length scales and at high temperatures can be performed with proper equipment. However, for these measurements, there is no commercially available high-magnification lens that will allow images to be taken ...
Microheater Array Powder Sintering (Maps) For Printing Flexible Electronics, 2018 University of Arkansas, Fayetteville
Microheater Array Powder Sintering (Maps) For Printing Flexible Electronics, Nicholas Holt
Theses and Dissertations
Microheater array powder sintering (MAPS) is a novel additive manufacturing process that uses an array of microheaters to selectively sinter powder particles. MAPS shows great promise as a new method of printing flexible electronics by enabling digital curing of conductive inks on a variety of substrates. MAPS operation relies on establishing a precision air gap of a few microns between an array of microheaters, which can reach temperatures of 600°C, and a layer of conductive ink which can be deposited onto a flexible substrate. This system presents challenges, being: the fabrication of a microheater that can reach suitable temperatures ...
Novelis Teaching Table, 2018 Kennesaw State University
Novelis Teaching Table, Phillip Laplante, Robert Hemker, Taylor Mcgriff, Juan Restrepo, Shelly Abraham
Honors College Capstones and Theses
Novelis is a company that specializes in metal casting, recycling, and rolling. They primarily focus on aluminum rolling for cans and car bodies but are an industry leader in numerous related areas. As the rolling process is not taught in most general engineering courses, Novelis periodically teaches new engineers and technicians about the specifics of this relatively mathematically complex process. Most of the current teaching methods are through PowerPoint presentations and group exercises, with minimal hands-on involvement. One of the most useful tools for teaching the rolling process is an actual jeweler’s rolling mill, which Novelis currently possesses, but ...
Numerical Simulation Of A High Strain Rate Biaxial Compression Apparatus, 2018 Washington University in St. Louis
Numerical Simulation Of A High Strain Rate Biaxial Compression Apparatus, Michael Lagieski
Engineering and Applied Science Theses & Dissertations
Few experimental methods today are capable of exploring the strength of materials at high strain rates (105 s-1). Those that are capable, such as the Split Hopkinson Bar, Taylor Anvil and Plate Impact suffer from instability and are generally limited to one dimensional wave propagation. Of particular interest is material response under biaxial compression, similar to that seen in inertial confinement fusion. Laser fusion fuel pellets typically undergo large strain rates as well as plastic deformation and non-linear behavior. This work briefly outlines an experimental procedure designed to replicate these large strain rates under biaxial compression using spherical ...
Rotordynamic Analysis Of Theoretical Models And Experimental Systems, 2018 California Polytechnic State University - San Luis Obispo
Rotordynamic Analysis Of Theoretical Models And Experimental Systems, Cameron R. Naugle, Cameron Rex Naugle
Master's Theses and Project Reports
This thesis is intended to provide fundamental information for the construction and
analysis of rotordynamic theoretical models, and their comparison the experimental
systems. Finite Element Method (FEM) is used to construct models using Timoshenko
beam elements with viscous and hysteretic internal damping. Eigenvalues
and eigenvectors of state space equations are used to perform stability analysis, produce
critical speed maps, and visualize mode shapes. Frequency domain analysis
of theoretical models is used to provide Bode diagrams and in experimental data
full spectrum cascade plots. Experimental and theoretical model analyses are used
to optimize the control algorithm for an Active Magnetic Bearing ...
Investigation Of Discrete Element Methods For Stud To Turf Interactions, 2018 Western Michigan University
Investigation Of Discrete Element Methods For Stud To Turf Interactions, Justin Rittenhouse
Artificial turf is frequently used in sports today and attempts to advantageously replicate a natural grass/soil playing surface. Despite numerous advantages, the technology is correlated with an increase in injuries. The concept behind this research is to create and validate a discrete element model (DEM) for the ground/foot interaction through the use of open source software. After validation, the goal is to analyze an arrangement of studs to determine what role stud geometry plays on torque [N-mm] and force [N] generation. The validation data was provided through laboratory experiments. Three football studs attached to a rigid bracket were ...
Experimental Investigation Of A New Spiral Wingtip, 2018 International Islamic University - Malaysia
Experimental Investigation Of A New Spiral Wingtip, Naseeb Ahmed Siddiqui, Mohamed Aldeeb, Waqar Asrar, Erwin Sulaeman
International Journal of Aviation, Aeronautics, and Aerospace
Experiments on the relative merits and demerits of slotted wingtips mimicking a bird’s primary feathers have been performed. The real emargination length of feather tips, their flexibility and curved shapes during cruise are considered in the present study. The experiments were performed at a Reynolds number of 3.7 x 105 on a symmetric flat plate half wing of aspect ratio 3. Lift, drag and pitching moments were measured using a six component aerodynamic balance. Four different shapes inspired by bird primary feathers have been analysed. The rigid curved tip performed the best increasing the L/D ratio ...