Graphene Twistronics: Tuning The Absorption Spectrum And Achieving Metamaterial Properties, 2023 Jouf University
Graphene Twistronics: Tuning The Absorption Spectrum And Achieving Metamaterial Properties, Ammar Armghan, Meshari Alsharari, Khaled Aliqab, Osamah Alsalman, Juveriya Parmar, Shobhit K. Patel
Department of Mechanical and Materials Engineering: Faculty Publications
Graphene twistronics using multilayer graphene is presented in such a way that it provides a metamaterial effect. This manuscript also analyzes the prediction of behavior using machine learning. The metamaterial effect is achieved by twisting the graphene layers. Graphene twistronics is a new concept for changing the electrical and optical properties of bilayer graphene by applying a small angle twist between the layers. The angle twists of 5o, 10o, and 15o are analyzed for the proposed graphene twistronics design. Tuning in the absorption spectrum is achieved by applying small twists to the angles of the …
Heterogeneous Sensor Data Fusion For Multiscale, Shape Agnostic Flaw Detection In Laser Powder Bed Fusion Additive Manufacturing, 2023 Virginia Polytechnical Institute
Heterogeneous Sensor Data Fusion For Multiscale, Shape Agnostic Flaw Detection In Laser Powder Bed Fusion Additive Manufacturing, Benjamin Bevans, Christopher Barrett, Thomas Spears, Aniruddha Gaikwad, Alex Riensche, Harold (Scott) Halliday, Prahalada Rao
Department of Mechanical and Materials Engineering: Faculty Publications
We developed and applied a novel approach for shape agnostic detection of multiscale flaws in laser powder bed fusion (LPBF) additive manufacturing using heterogenous in-situ sensor data. Flaws in LPBF range from porosity at the micro-scale (< 100 μm), layer related inconsistencies at the meso-scale (100 μm to 1 mm) and geometry-related flaws at the macroscale (> 1 mm). Existing data-driven models are primarily focused on detecting a specific type of LPBF flaw using signals from one type of sensor. Such approaches, which are trained on data from simple cuboid and cylindrical-shaped coupons, have met limited success when used for detecting multiscale flaws in complex LPBF parts. The objective of this work is to develop a heterogenous sensor data fusion …
Reflect To Connect, 2023 California Polytechnic State University, San Luis Obispo
Reflect To Connect, Sophia Rae Guzules
Liberal Arts and Engineering Studies
Engineering statics is an important course and a prerequisite for many subsequent courses for many engineering majors. It is often students’ first exposure to technical engineering sciences. Most statics concepts are addressed in ways disconnected from students’ prior experiences and interests. Utility Value Interventions (UVIs) have been employed in fields like biology and chemistry to help students connect concepts in class and their lives outside the classroom. However, UVI usage in engineering so far has been limited. In this Senior Project paper, I will describe the process that the team Critical Research in Engineering and Technology Education (CREATE) and I …
Accurate Evaluation Of The Direction-Dependent Mechanical Properties Of Ideal Single Crystals: A Comparative Ab Initio Study, 2023 American University in Cairo
Accurate Evaluation Of The Direction-Dependent Mechanical Properties Of Ideal Single Crystals: A Comparative Ab Initio Study, Jaylan Ali Elhalawani
Theses and Dissertations
The mechanical properties of a single crystal or a grain in a polycrystalline material are highly dependent on the direction of the applied load. Key properties of interest are the Young’s modulus and the Poisson ratio in the small strain limit, and the ideal tensile strength in the large strain regime. Prior atomistic computations of these properties interchangeably used two approaches. In one approach the stress-strain response is explicitly calculated via a numerical tensile test experiment. In the second approach the second order single crystal elastic constants are computed via small deformations and then used in analytical equations to derive …
Interfaces In Dynamic Brittle Fracture Of Pmma: A Peridynamic Analysis, 2023 University of Nebraska-Lincoln
Interfaces In Dynamic Brittle Fracture Of Pmma: A Peridynamic Analysis, Longzhen Wang, Javad Mehrmashhadi, Florin Bobaru
Department of Mechanical and Materials Engineering: Faculty Publications
Recent experiments in bonded PMMA layers have shown dramatic changes in dynamic crack growth characteristics depending on the interface location and toughness. In this paper we present a peridynamic (PD) analysis of this phenomenon and determine three elements that are essential in a model reproducing the observed fracture behavior: (1) softening near the crack tip to account for changes in PMMA due to heat-generation induced by the high strain rates reached around the crack tip in dynamic fracture; (2) independent extension (mode I) and shear (mode II) modes of fracture; (3) a two-parameter fracture model, which matches both strength and …
Locally Resonant Metasurface For Low-Frequency Transmissive Underwater Acoustic Waves, 2023 Wuhan University of Technology
Locally Resonant Metasurface For Low-Frequency Transmissive Underwater Acoustic Waves, Zhong Chen, Shenghong Guan, Qiang Xie, Zheng Li, Zhongmei Gao, Mehrdad Negahban
Department of Mechanical and Materials Engineering: Faculty Publications
Introduction: Acoustic metasurfaces for underwater wave manipulation have great potential use, but the strong solid-fluid interaction caused by impedance closeness between the structure and water brings design difficulty, especially in the low-frequency range.
Methods: Here a locally resonant metasurface for transmissive underwater acoustic waves is proposed using finite element method for which each metasurface unit consists of one channel and three subunits. Each subunit has one plate and two rubber spacers to form a resonator. By changing the height ratio of the plate over the subunit, arbitrary phase shifts within the full 2π coverage can be obtained at …
Mechanical Design Of A Microwave Imaging Device For Breast Cancer Detection In Mri Scanners, 2023 Dartmouth College
Mechanical Design Of A Microwave Imaging Device For Breast Cancer Detection In Mri Scanners, Grace M. Player
Dartmouth College Master’s Theses
This project seeks to develop an updated version of a microwave imaging device for use in conjunction with breast MRI, improving upon existing technology and developing novel concepts for the device. It posits three primary redesign targets for updating the previous system: resizing the system height, making the device more iteration- friendly, and improving the overall manufacturability of the device by replacing custom components with commercially available alternatives. All three of these redesign targets are met in the new design, V2.0. The height is reduced by reducing antenna travel and height, embedding some components, and shortening the tank wall, resulting …
Pneumatic Latched Demultiplexer Circuit For Controlling Multi-Actuator Soft Robots, 2023 Bucknell University
Pneumatic Latched Demultiplexer Circuit For Controlling Multi-Actuator Soft Robots, Arsh Noor Amin
Master’s Theses
This thesis presents a novel method for controlling multi-actuator soft robots using pneumatic latched demultiplexer circuits implemented with monolithic membrane valves. The pneumatic circuits are designed to address the problems of heavy dependence on hard electrical components and lack of feasible multi-actuator soft robotic systems that limit the potential applications of soft robotics. The proposed pneumatic demultiplexers reduce the number of solenoid valves and electrical components required to drive soft robotic systems, making soft robot control mechanisms more compliant, scalable, and versatile. The thesis demonstrates the design, fabrication, and testing of 4-bit and n-bit pneumatic demultiplexer circuits that can control …
Investigation Of Oxidation And Corrosion Resistance Of Ni-Based Alloys And Stainless Steels Under Co2 Environments At Elevated Temperatures, 2023 West Virginia University
Investigation Of Oxidation And Corrosion Resistance Of Ni-Based Alloys And Stainless Steels Under Co2 Environments At Elevated Temperatures, Spencer Roy Fultineer
Graduate Theses, Dissertations, and Problem Reports
High mechanical strength integrity, high robustness towards oxidation, and high resistance to carburization under CO2 environments at elevated temperatures are usually required for metallic systems that are employed for power generation. INCONEL 625 is a nickel-based superalloy that started development in the 1950s. This material was designed with the distinct purpose of use in high-temperature and high-pressure systems. While various materials possess the physical properties to handle these conditions, the creation of IN625 addresses the need for a material to withstand the highly corrosive properties of these kinds of environments. In order to evaluate the oxidation and corrosion resistance of …
A Comparative Analysis Of Coastdown Testing Methods From An Electric Drive Unit Engagement Perspective Using A Student-Designed Parallel Hybrid Electric Vehicle, 2023 West Virginia University
A Comparative Analysis Of Coastdown Testing Methods From An Electric Drive Unit Engagement Perspective Using A Student-Designed Parallel Hybrid Electric Vehicle, Dawson Everett Dunnuck
Graduate Theses, Dissertations, and Problem Reports
Coastdown testing and road load determination are pivotal parts of the automotive design process. Vehicle manufacturers and independent companies perform and analyze road loads determined through a coastdown or similar method to determine a vehicle’s road load for modeling and EPA certification. For a traditional coastdown, the vehicle’s drivetrain must be disconnected through a clutch between the engine and the transmission while traveling at a high rate of speed to place the vehicle in neutral. This changes for hybrid and electric vehicles. Some hybrid, and most electric, vehicles delivered to customers do not have this clutch action to grant the …
4wd Baja Upright And Wheel Hub, 2023 The University of Akron
4wd Baja Upright And Wheel Hub, Nathan Thompson, Jonathan P. Larson, Spencer D. Compan
Williams Honors College, Honors Research Projects
The University of Akron Zips Baja Team has switched to a 4-wheel-drive (4WD) vehicle as per the 2023 Baja Society of Automotive Engineers (SAE) rules. The 2022 Baja Vehicle was 2WD, thus the upright and wheel hub were designed exclusively for a 2-wheel-drive (2WD) Baja vehicle. This report entails the design process and methods of verification for the design of the 4WD upright and wheel hub.
Study Of Nanocomposite Materials Using Molecular Dynamics, 2023 Michigan Technological University
Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad
Dissertations, Master's Theses and Master's Reports
There is an increase in demand for new lightweight structural materials in the aerospace industry for more efficient and affordable human space travel. Polymer matrix composites (PMCs) with reinforcement material as carbon nanotubes (CNTs) have shown exceptional increase in the mechanical properties. Flattened carbon nanotubes (flCNTs) are a primary component of many carbon nanotube (CNT) yarn and sheet materials, which are promising reinforcements for the next generation of ultra-strong composites for aerospace applications. These flCNT/polymer materials are subjected to extreme pressure and temperature during curing process. Therefore there is a need to investigate the evolution of properties during the curing …
On The Gaussian-Core Vortex Lattice Model For The Analysis Of Wind Farm Flow Dynamics, 2023 Michigan Technological University
On The Gaussian-Core Vortex Lattice Model For The Analysis Of Wind Farm Flow Dynamics, Apurva Baruah
Dissertations, Master's Theses and Master's Reports
Wind power science has seen tremendous development and growth over the last 40 years. Advancements in design, manufacturing, installation, and operation of wind turbines have enabled the commercial deployment of wind power generation systems. These have been due, in a large part, to the expertise in the simulation and modeling of individual wind turbines. The new generation of wind energy systems calls for a need to accurately predict and model the entire wind farm, and not just individual turbines. The commercial deployment of these wind farms depends on model's ability to accurately capture the different physics involved, each at its …
Traversing With Quantitative Fidelity Through The Glass Transition Of Amorphous Polymers: Modeling The Thermodynamic Dilatational Flow Of Polycarbonate, 2023 University of Nebraska-Lincoln
Traversing With Quantitative Fidelity Through The Glass Transition Of Amorphous Polymers: Modeling The Thermodynamic Dilatational Flow Of Polycarbonate, Mehrdad Negahban, Wenlong Li, Jean-Marc Saiter, Laurent Delbreilh, Kyle Strabala, Zheng Li
Department of Mechanical and Materials Engineering: Faculty Publications
We follow the assumption that the dilatational response of glassy polymers can be characterized by a back-stress type analog that includes a thermal expansion for each elastic component, and with a viscosity that is dependent on the expansion of the elastic back stress component. To this, we add the assumption of an unloaded equilibrium temperature that correlates to the past processing through the viscous flow. After setting this in a thermodynamically consistent structure, the elastic, elastic backstress, thermal expansion, back-stress thermal expansion, heat capacity and viscous damping are evaluated using existing experiments for the response of polycarbonate over the glassy …
An Efficient And Low-Cost Method To Create High-Density Nitrogen-Vacancy Centers In Cvd Diamond For Sensing Applications., 2023 Wichita State University
An Efficient And Low-Cost Method To Create High-Density Nitrogen-Vacancy Centers In Cvd Diamond For Sensing Applications., Prem Bahadur Karki, Rupak Timalsina, Mohammadjavad Dowran, Ayodimeji E. Aregbesola, Abdelghani Laraoui, Kapildeb Ambal
Department of Mechanical and Materials Engineering: Faculty Publications
The negatively charged Nitrogen-Vacancy (NV-) center in diamond is one of the most versatile and robust quantum sensors suitable for quantum technologies, including magnetic field and temperature sensors. For precision sensing applications, densely packed NV- centers within a small volume are preferable due to benefiting from 1/√𝑁 sensitivity enhancement (N is the number of sensing NV centers) and efficient excitation of NV centers. However, methods for quickly and efficiently forming high concentrations of NV- centers are in development stage. We report an efficient, low-cost method for creating high-density NV- centers production from a relatively …
Peridynamic Simulation Of Elastic Wave Propagation By Applying The Boundary Conditions With The Surface Node Method, 2023 Università degli Studi di Padova
Peridynamic Simulation Of Elastic Wave Propagation By Applying The Boundary Conditions With The Surface Node Method, Francesco Scabbia, Mirco Zaccariotto, Ugo Galvanetto, Florin Bobaru
Department of Mechanical and Materials Engineering: Faculty Publications
Peridynamics is a novel nonlocal theory able to deal with discontinuities, such as crack initiation and propagation. Near the boundaries, due to the incomplete nonlocal region, the peridynamic surface effect is present, and its reduction relies on using a very small horizon, which ends up being expensive computationally. Furthermore, the imposition of nonlocal boundary conditions in a local way is often required. The surface node method has been proposed to solve both the aforementioned issues, providing enhanced accuracy near the boundaries of the body. This method has been verified in the cases of quasi-static elastic problems and diffusion problems evolving …
Correction: Nanoscale Imaging Of Antiferromagnetic Domains In Epitaxial Films Of Cr2o3 Via Scanning Diamond Magnetic Probe Microscopy, 2023 University of Nebraska-Lincoln
Correction: Nanoscale Imaging Of Antiferromagnetic Domains In Epitaxial Films Of Cr2o3 Via Scanning Diamond Magnetic Probe Microscopy, Adam Erickson, Syed Qamar Abbas Shah, Ather Mahmood, Ilja Fescenko, Rupak Timalsina, Christian H. Binek, Abdelghani Laraoui
Department of Mechanical and Materials Engineering: Faculty Publications
Correction for ‘Nanoscale imaging of antiferromagnetic domains in epitaxial films of Cr2O3 via scanning diamond magnetic probe microscopy’ by Adam Erickson et al., RSC Adv., 2023, 13, 178–185, https:// doi.org/10.1039/D2RA06440E
Design Of Force Indicator For Ballistic Armor Trauma Pad, 2023 The University of Akron
Design Of Force Indicator For Ballistic Armor Trauma Pad, William Keenan, Anthony Cinalli, Patrick Kennedy
Williams Honors College, Honors Research Projects
The purpose of the Force Indicator for Ballistic Armor Vests is to obtain an approximate value for the impact a bullet delivers through a trauma pad after the Kevlar layer stops the initial bullet. This approximation will be applied in the field to assist in medical treatment of gunshot wounds. The indicator is made from a pressure-sensitive film located behind the Kevlar layer and trauma pad, and it can be easily removed in the field for examination. The impact vest and force indicator are self-contained for ease of implementation. The device will be tested with 9mm, .22 Long Rifle, and …
Fluid Power Vehicle Challenge, 2023 The University of Akron
Fluid Power Vehicle Challenge, Bryce Towne, Ethan Andrews, Carter Moore, Andrew Sobel
Williams Honors College, Honors Research Projects
The Fluid Power Vehicle Challenge is a competition held by the National Fluid Power Association (NFPA) that challenges students to create a hydraulically powered vehicle to compete in four different races over two days. The vehicle has to be fully powered by hydraulics, with human power (such as pedaling) being used to move the hydraulic fluid. Electronics and pneumatics can be used to control the flow of the hydraulic oil. Vehicles also must have an energy storage device to take advantage of regenerative braking. The final competition was at the Norgren facility in Colorado from April 12th to April 14th. …
Distillery, 2023 The University of Akron
Distillery, Clare Nicholas, Patrick Hanlon
Williams Honors College, Honors Research Projects
The goal for this project is to make a cost effective still. We will be implementing cost saving parts to create a cheap but effective still. From initial research conducted, we will try to combine a stainless steel still and copper still together so that the cheaper material (stainless steel) and the component that removes sulfur compounds (copper) are both implemented. The ME side of the project will focus on the actual design and construction of the parts that will be implemented into the still. Included in the design process will be calculations of heat transfer for the current and …