Other Mechanical Engineering Commons^™

Plasmon Enhanced Quantum Properties Of Single Photon Emitters With Hybrid Hexagonal Boron Nitride Silver Nanocube Systems, Mohammadjavad Dowran, Andrew Butler, Suvechhya Lamichhane, Adam Erickson, Ufuk Kilic, Sy_Hwang Liou, Christos Argyropoulos, A. Laraoui

Department of Mechanical and Materials Engineering: Faculty Publications

Hexagonal boron nitride (hBN) has emerged as a promising ultrathin host of single photon emitters (SPEs) with favorable quantum properties at room temperature, making it a highly desirable element for integrated quantum photonic networks. One major challenge of using these SPEs in such applications is their low quantum efficiency. Recent studies have reported an improvement in quantum efficiency by up to two orders of magnitude when integrating an ensemble of emitters such as boron vacancy defects in multilayered hBN flakes embedded within metallic nanocavities. However, these experiments have not been extended to SPEs and are mainly focused on multiphoton effects. …

Assessing High Dynamic Range Imagery Performance For Object Detection In Maritime Environments, Erasmo Landaeta

Doctoral Dissertations and Master's Theses

The field of autonomous robotics has benefited from the implementation of convolutional neural networks in vision-based situational awareness. These strategies help identify surface obstacles and nearby vessels. This study proposes the introduction of high dynamic range cameras on autonomous surface vessels because these cameras capture images at different levels of exposure revealing more detail than fixed exposure cameras. To see if this introduction will be beneficial for autonomous vessels this research will create a dataset of labeled high dynamic range images and single exposure images, then train object detection networks with these datasets to compare the performance of these networks. …

Neural Network Fusion Of Multi-Modal Sensor Data For Autonomous Surface Vessels, David J. Thompson

Doctoral Dissertations and Master's Theses

Autonomous surface vessels (ASV) can potentially improve the safety of vessels traditionally operated by humans. Despite advancements in autonomous on-road vehicles, many of these advancements have yet to be realized for ASVs. This is primarily due to lacking ASV sensing platforms and public datasets for ASV-based perception research. To that end, this dissertation demonstrates the design of a synchronized multi-modal sensing platform for ASVs utilizing GPS/INS, LiDAR, LWIR cameras, HDR camera, and high-resolution cameras. The sensing platform is designed to maximize the overlap of sensors for multi-modal research and provides accurate intrinsic and extrinsic calibration between each sensor. Furthermore, the …

Development Of Mirror Flexures For Use In The Muvi Instrument, Colin W. Harrop

Master's Theses

The Miniaturized Ultraviolet Imager (MUVI), is a compact wide field UV imaging instrument in development at UC Berkeley Space Sciences Laboratory and Cal Poly, San Luis Obispo. MUVI is designed to fit in a 2U CubeSat form factor and provide wide field, high resolution images of the ionosphere at far ultraviolet wavelengths. This thesis details the design and analyses of MUVI’s deployable cover mirror mounting flexures. Three different flexure geometries were evaluated, an optimal candidate was determined based on a number of criteria including isolation of vibration and stress to the mirrors, manufacturability and cost. The design of the flexure …

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 5^o, 10^o, and 15^o 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, 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, 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 …

Multifunctional Microgel-Based Cream Hydrogels For Postoperative Abdominal Adhesion Prevention, Bo Liu, Yunfan Kong, Olawale A. Alimi, Mitchell Kuss, Huiyin Tu, Wenfeng Hu, Abu Rafay, Kumar Vikas, Wen Shi, Megan Lerner, William L. Berry, Yulong Li, Mark A. Carlson, Bin Duan

Department of Mechanical and Materials Engineering: Faculty Publications

Postoperative abdominal adhesions are a common problem after surgery and can produce serious complications. Current anti-adhesive strategies focus mostly on physical barriers and are unsatisfactory and inefficient. In this study, we designed and synthesized advanced injectable cream-like hydrogels with multiple functionalities, including rapid gelation, self-healing, anti-oxidation, anti-inflammation, and anti-cellular adhesion. The multifunctional hydrogels were facilely formed by the conjugation reaction of epigallocatechin gallate (EGCG) and hyaluronic acid (HA)-based microgels and polyvinyl alcohol (PVA) based on the dynamic boronic ester bond. The physicochemical properties of the hydrogels including anti-oxidative and anti-inflammatory activities were systematically characterized. A mouse cecum-abdominal wall adhesion model …

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, 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, 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 …

Jack And Alex Rc-Baja, Alex Vornbrock

All Undergraduate Projects

Teams of two mechanical engineering students were tasked with the construction of an RC Baja car qualified by the rules and regulations of the Baja competition as well as specifications set by the individual team member for their portion of the vehicle. This proposal focuses on the Chassis and Drivetrain of the vehicle while team member Jack Stutz oversaw the steering and suspension. Teams will compete against each other in various modes to determine the best vehicles of the competitors. The chassis was made of standard aluminum, the remaining parts made by the students were made with PLA; both materials …

Rc Baja Project: Suspension And Steering, Chance Hills

All Undergraduate Projects

Students designed and manufactured an RC Baja car to compete in the ASME RC Baja competition. The goal of this section of the project was to create a steering system and suspension system that work together properly with a partner’s chassis/drive train systems during tests and competitions. The car needed to be able to complete in the three events, which are a drag race, a solemn course, and the Baja event. The RC will also be evaluated on the ability to climb inclines, top speed, and withstand the drop test. This proposal will explain all the details and effort that …

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 …

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

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 …

Jcati Carbon Fiber Recycler: Crusher System, Devin Riley

All Undergraduate Projects

With a substantial rise in Carbon Fiber use across all industries, the need for a way to recycle the waste has grown as well. A group of Mechanical Engineering Technology students at Central Washington University funded by the Joint Center for Aerospace Technology (JCATI) have created a machine to recycle waste wing trimmings from the Boeing company’s airplanes. This machine consists of 5 different sub-assemblies being the oven, crusher, gear train, conveyor, and shredder. The purpose of this project was to decrease the deflection in the crusher caused by bulging in the housing and movement of the bearings. To decrease …

Using Long Short-Term Memory (Lstm) Networks With The Toy Model Concept For Compressible Pulsatile Flow Metering, Indranil Brahma

Faculty Journal Articles

The metering of periodically oscillating pulsating flow has traditionally relied on eliminating pulsations, which is not possible for many systems such as internal combustion engines. Recent advances in the Deep Learning Suite of tools allow the extraction of useful information from complex signals acquired by inexpensive sensors. In this work, Long Short-Term Memory (LSTM) networks have been proposed to meter highly compressible pulsatile flow by learning the relationship between the average flow rate and the temporal patterns of standard orifice measurements. The model was built and evaluated with separate training and testing datasets that had different pulsation frequencies and waveforms. …

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 …

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 …