Mechanical Engineering Commons^™

Orbital Angular Momentum Transformation Of Optical Vortex With Aluminum Metasurfaces, Yuchao Zhang, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The orbital angular momentum (OAM) transformation of optical vortex is realized upon using aluminum metasurfaces with phase distributions derived from the caustic theory. The generated OAM transformation beam has the well-defined Bessel-like patterns with multiple designed topological charges from -1 to +2.5 including both the integer-order and fractional-order optical vortices along the propagation. The detailed OAM transformation process is observed in terms of the variations of both beam intensity and phase profiles. The dynamic distributions of OAM mode density in the transformation are further analyzed to illustrate the conservation of the total OAM. The demonstration of transforming OAM states arbitrarily …

Spatial Variation Of Vector Vortex Beams With Plasmonic Metasurfaces, Yuchao Zhang, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The spatial variation of vector vortex beams with arbitrary polarization states and orbital angular momentum (OAM) values along the beam propagation is demonstrated by using plasmonic metasurfaces with the initial geometric phase profiles determined from the caustic theory. The vector vortex beam is produced by the superposition of deflected right- and left-handed circularly polarized component vortices with different helical phase charges, which are simultaneously generated off-axially by the single metasurface. Besides, the detailed evolution processes of intensity profile, polarization distribution and OAM value along the beam propagation distance is analyzed. The demonstrated arbitrary space-variant vector vortex beam will pave the …

Spontaneous Emission Rate Enhancement With Aperiodic Thue-Morse Multilayer, Ling Li, Cherian J. Mathai, Shubhra Gangopadhyay, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The emergence of multilayer metamaterials in the research field of enhancing spontaneous emission rates has recently received extensive attention. Previous research efforts mostly focus on periodic metal-dielectric multilayers in hyperbolic dispersion region; however, the influence of lattice order in subwavelength multilayers on spontaneous emission is rarely studied. Here, we observe the stronger Purcell enhancement of quantum dots coupled to the aperiodic metal-dielectric multilayer with Thue-Morse lattice order from elliptical to hyperbolic dispersion regions, compared to the periodic multilayer with the same metal filling ratio. This work demonstrates the potential of utilizing quasiperiodic metamaterial nanostructures to engineer the local density of …

Accelerated Relaxation In Disordered Solids Under Cyclic Loading With Alternating Shear Orientation, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

The effect of alternating shear orientation during cyclic loading on the relaxation dynamics in disordered solids is examined using molecular dynamics simulations. The model glass was initially prepared by rapid cooling from the liquid state and then subjected to cyclic shear along a single plane or periodically alternated in two or three dimensions. We showed that with increasing strain amplitude in the elastic range, the system is relocated to deeper energy minima. Remarkably, it was found that each additional alternation of the shear orientation in the deformation protocol brings the glass to lower energy states. The results of mechanical tests …

Characterization Of Thermo-Mechanical Properties Of Copper Nano-Particles Infused Acrylonitrile Butadiene Styrene (Abs)- 3d Printed Specimens, Viswajit Talluru

Mechanical and Aerospace Engineering Theses - Archive

Now a days the use of metal nanoparticle infused polymer is becoming widespread, since the development of polymer with enhanced thermal properties are being used for the growth of electronic packaging industry. In this study, copper nanoparticles are mixed with the Acrylonitrile Butadiene Styrene (ABS) thermoplastic in varying mass proportions, to observe the changes in thermal and structural properties of ABS. As expected, the extruded wire with high nano-particle concentration exhibited much higher thermal conductivity than its raw ABS form. For the case of 2% copper nanoparticle infused ABS using one dimensional steady state heat flux method though extrude wire …

Publisher Correction: Pore Elimination Mechanisms During 3d Printing Of Metals (Nature Communications, (2019), 10, 1, (3088), 10.1038/S41467-019-10973-9), S. Mohammad H. Hojjatzadeh, Niranjan D. Parab, Wentao Yan, Qilin Guo, Lianghua Xiong, Cang Zhao, Mimglei Qu, Luis I. Escano, Xianghui Xiao, Kamel Fezzaa, Wes Everhart, Tao Sun, Lianyi Chen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The original version of this Article contained an error in Fig. 4. The x-axis labels in Fig. 4a, b were incorrectly labelled 'Diameter (mm)', rather than the correct 'Diameter (µm)'. This has been corrected in both the PDF and HTML versions of the Article.

Gearbox Baffle Optimization, Megan Arduin

Masters Theses

Current literature reveals there is limited consensus on the placement of baffles within a gearbox to reduce churning losses. Thus, there is a need for a process to identify baffle clearances that result in maximum and minimum churning losses. There are two types of baffles: axial and radial. While both axial and radial baffles cause reductions in churning losses to various degrees, the focus is on the effect of radial baffles. The effect of a board (rectangular plate) baffle location on the churning losses of a single gear gearbox are evaluated using computational fluid dynamics (CFD) implemented in Ansys. Several …

Isolated Nucleus Stiffens In Response To Low Intensity Vibration, Joshua Newberg

Boise State University Theses and Dissertations

The nucleus, central to all cellular activity, relies on both direct mechanical input and its molecular transducers to sense and respond to external mechanical stimuli. This response occurs by regulating intra-nuclear organization that ultimately determines gene expression to control cell function and fate. It has long been known that signals propagate from an extracellular environment to the cytoskeleton and into nucleus (outside-in signaling) to regulate cell behavior. Emerging evidence, however, shows that both the cytoskeleton and the nucleus have inherent abilities to sense and adapt to mechanical force, independent of each other. While it has been shown that isolated nuclei …

Waste Gasification, Glyn D. Lewis, Nash Taylor, Nicholas L. Ordonez, David S. Mccallum

Mechanical Engineering

This document summarizes the work the IGT Team has conducted on the topic of waste to energy gasification over the Cal Poly Winter, Spring, and Fall quarters of 2019. The project is being carried out by four Cal Poly Mechanical Engineering students: Nash Taylor, Glyn Lewis, David McCallum, and Nicholas Ordonez and the sponsor of this project is Tod duBois. The team’s original goal was to successfully create a system that compiles residential solid waste on a small scale, gasifies it, and measures the typical syngas outputs, so that the team may assess the viability of gasification of household waste …

Deployable Cover For Cubesat Fuv Imager, Edwin J. Rainville, Patrick J. Rainville, Jeff Wagner

Mechanical Engineering

The goal is to develop a deployable cover for a far ultraviolet imager cube satellite that will be used to map the earth’s auroras in the ionosphere. The deployable cover is used to protect the Far Ultra-Violet (FUV) sensor and lenses, house two mirrors which are used to filter unwanted light and expose optics when deployed. The deployable cover consists of a door, an actuator, a lockout mechanism, and an “open position” indicator. This project also includes designing a fixture for testing the optical alignment of the deployable cover after launch and during orbital conditions. The subassembly is required to …

Model Block Press Design, Ben Todd Van Hamersveld, Chester Wong, Alexander Wing-Jon Giannousis

Mechanical Engineering

This project’s goal is to redesign the Center for Vocational Building Technology (CVBT) BP9 earth block press, which makes 1/3 scale compressed earth blocks to build demonstration model homes in Thailand. The full-scale block press, the BP6, provides a sustainable and affordable technique for constructing habitable homes in Thailand. The BP9 serves as a tool to inform the public of the advantages of human-powered earth block presses through demonstration. The BP9 press design has multiple problems: it is too expensive to manufacture, there is too much friction when used, it has several weak points due to users unintentionally applying excessive …

Mad Jack Alpine Touring Model Design, Austin Gasbarra, Gillian Stargensky, Madeleine Mccool, Brannon Smudz

Mechanical Engineering

Skiing is a sport enjoyed by millions of people every year, yet ski boots are very uncomfortable and cost- prohibitive, resulting in a low conversion rate of first-time skiers to lifetime skiers. Additionally, Alpine Touring (AT) is seeing a surge in popularity as ski resorts become more expensive, but few companies are developing affordable products in this realm. Mad Jack Snow Sports has developed a product that they believe addresses some of the main issues associated with skiing, but they want to develop their product line further. The problem statement and scope state that the purpose of this project is …

Critical Radius Of Insulation, Maria N. Ambrose, Samuel J. Sayre, Travis W. Martin, Matt T. Sterling

Mechanical Engineering

The critical radius of insulation is a counterintuitive concept within the study of heat transfer. The theory states that adding insulation to a cylindrical or spherical object will increase the rate of heat loss rather than decrease it, if the radius (thickness) of the insulation is at its “critical” value. The Critical Radius of Insulation Senior Project is designed to demonstrate this phenomenon to Heat Transfer students via a portable apparatus. The concept will be demonstrated with a cylindrical object which is heated by way of a separate voltage source. Thermocouples will display the temperature of the cylinder while insulation …

Exploring Convergence Of Snake Skin-Inspired Texture Designs And Additive Manufacturing For Mechanical Traction, Catherine Sue Tiner

Graduate Theses and Dissertations

This research focuses on the understanding, development, and additive manufacture of a 3D printed snake skin-inspired texture pattern. The design functionalities of snake skin were determined through the study of the snake species Python Regius otherwise known as the ball python. Each scale of a snake has hierarchical texture with hexagonal macro-patterns aligned on the ventral surface of the skin with overriding anisotropic micro textured patterns such as denticulations and fibrils. Using a laser-powder bed fusion (L-PBF) process, 420 stainless steel samples were 3D printed which closely resemble the above described directional texture of natural snake skin. This printed surface …

Flight Test Data System For Strain Measurement, Zachary David Wilson

Master's Theses

This thesis describes the design and evaluation of two devices to be included in the next generation of the family of devices called the Boundary Layer Data System (BLDS). The first device, called the Quasi-Static Strain Data Acquisition System, is a continuation of the BLDS-M series of devices to be known as the Flight Test Data System (FTDS) that uses a modular approach to acquire non-flow, quasi-static mechanical strain measurements. Various breakout boards and development boards were used to synthesize the device, which were housed by a custom PCB board. The system is controlled by the Simblee^TM System on …

Me-Em Enewsbrief, December 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Development And Characterization Of A Biopolymer Direct-Write Process For 3d Microvascular Structures Formation., Xiaoming Fan

Electronic Theses and Dissertations

Engineering of bulk tissues has been limited by the lack of nutrient and waste exchange in these tissues without an adjacent capillary network. To produce microvasculature, a scaffold must be produced that provides temporary mechanical support and stimulate endothelial cell adhesion, growth, and morphogenesis into a vessel. However, current well-established techniques for producing microvasculature, such as electrospinning, are limited since they lack both the precision to control fiber placement in three-dimensional space and the ability to create fiber networks with predefined diameters to replicate the physiological microvascular progression from arteriole to capillary to venule. Our group has developed a “Direct-write” …

Fiberglass Mat-Roll Carryover, Bryce Youngson, Aaliyah Ramos, Johann Cayaban, Tony Ledesma

Mechanical Engineering

The asphalt shingle is a type of roof shingle that uses asphalt for waterproofing. Its low cost and easy installation make it one of the most common roof covers in North America. General Aniline and Film (GAF) is one of the nation’s largest manufacturers of roofing materials and produces asphalt shingles at their Shafter, California manufacturing facility. To manufacture asphalt shingles, a base material of fiberglass passes through a series of processes that sequentially add asphalt, ceramic-coated mineral granules, and thermoplastic adhesive. The fiberglass base-material arrives at the manufacturing facility in large rolls that workers must periodically splice together in …

Evaluation Of The Most Significant Factors Influencing The Production Rates Of Highway Construction Activities, Angelica M. Neira

Theses and Dissertations

The utilization of realistic production rates is key for the accurate estimation of the contract time in highway projects. Several factors have an impact on production rates and change the total duration of construction projects. To organize and complete projects in a timely, quality and financially responsible manner, projects need to be scheduled carefully. Schedulers and planners of the Texas Department of Transportation (TxDOT) have been noticing that the estimated timelines are far from the reality and want to investigate if external factors can be the cause of this discrepancy. Some of the factors considered in this study are the …

An Advanced Approach For Contract Time Determination In Highway Projects, Cuauhtemoc Torres Cantu

Theses and Dissertations

In project management, finishing a project on schedule is one of the most important aspects. The Texas Department of Transportation (TxDOT) has been experiencing delays in some projects that can be accounted to an inaccurate project time estimation process. This research presents the development of a user-friendly and comprehensive computer-based contract time determination system. The enhanced system implements probabilistic scheduling techniques such as Program Evaluation and Review Technique, and Monte Carlo Simulation. Additionally, the application of a lognormal two-point PERT method is explored in this study. The new system proposes the use of a database of production rates based on …

Process Improvement And Lift Design For The Installation Of A Metrology Machine Assembly, Dalt J. Lasell, James Mitchell O'Meara, Matthew Steensma

Industrial and Manufacturing Engineering

The objective is to work with Onto Innovations, a leading provider of semiconductor metrology and manufacturing solutions, to develop a system that safely installs a 250lb optics plate into the Atlas III: one of their metrology machines. Based in Milpitas, CA, Onto Innovations utilizes a variety of operations to create different products and assembles each product on site. The 250lb optics plates are WIP that are transferred between fixtures and the Atlas III using a combination of lifts and human workers. The WIP have long lead times, high tolerances, and large costs associated with their manufacturing process.

Onto Innovations identified …

Automation Of Data Analysis In Formula 1, Adam Joseph Mourad, Prescott Jeanne Delzell, Patrick Conner Mccabe

Industrial and Manufacturing Engineering

This paper explores economic solutions for Formula 1 racing companies who are interested in data visualization tools. The research was conducted on the current development of data gathering, data visualization, and data interpretation in Formula 1 racing. It was found that a large chunk of racing companies within the league needs an affordable, effective, and automated visualization tool for data interpretation. As data collection in Formula 1 arises, the need for faster and more powerful software increases. Racing companies profit off-brand exposure and the more a racing team wins, the more exposure they receive. The goal of the paper focuses …

Axial Compressor Based On Plastic Additive Manufacturing, Chris Phu

Mechanical Engineering Undergraduate Honors Theses

Turbomolecular pumps designed to function in very low pressures tend to be too prohibitively expensive for student researchers. On the other hand, while conventional pumps are affordable, they can’t function in extreme low pressures. An additively manufactured axial compressor however is inexpensive to manufacturer and only needs to be build up enough pressure for a conventional pump to function. After many design iterations, a final iteration that is near vacuum chamber ready has been 3D printed and tested for spin functionally. The designed axial compressor is easy to assemble and very modular. Conclusions from each of the design iterations is …

Ultrasonic Wave Propagation In Copper/Graphene Metal Matrix Composites, Casey Lindbloom

Mechanical Engineering Undergraduate Honors Theses

Emerging metallic composite materials implanted with graphene sheets are showing immense promise, with benefits being observed with regards to mechanical, thermal, and electrical material properties. This research aims to investigate the effects on ultrasonic wave propagation in Copper/Graphene Metal Matrix Composites (Cu/Gr MMCs) with varying graphene arrangements inspired from nacre and bone nanoscale material distributions. To accomplish this, the molecular dynamics (MD) method is utilized to simulate nanoscale wave propagation on a set of Cu/Gr MMCs with differing graphene arrangements and volume percentages ranging up to 4.56%. The computational model results are then analyzed to determine the variation in energy …

Enabling Compact Devices Through Origami And Developable Mechanisms, Jacob Ryan Greenwood

Theses and Dissertations

This thesis provides resources that enable the design of novel and compact mechanical devices by providing terminology, engineering models, and design methods in the fields of developable mechanisms and origami-based engineering.The first part of this work presents engineering models to aid in the design of cylindrical developable mechanisms. These models take into account the added spatial restrictions imposed by the developable surface. Equations are provided for the kinematic analysis of cylindrical developable mechanisms. A new classification for developable mechanisms is also presented (intramobile, extramobile, and transmobile) and two graphical methods are provided for determining this classification for single-DOF planar cylindrical …

Characterization Of Local Void Content In Carbon Fiber Reinforced Plastic Parts Utilizing Observation Of In Situ Fluorescent Dye Within Epoxy, Wyatt Young Warner

Theses and Dissertations

Experimentation exploring the movement of voids within carbon fiber reinforced plastics was performed using fluorescent dye infused into the laminates observed through a transparent mold under ultraviolet light. In situ photography was used as an inspection method for void content during Resin Transfer Molding for these laminates. This in situ inspection method for determining the void content of composite laminates was compared to more common ex-situ quality inspection methods i.e. ultrasonic inspection and cross-section microscopy. Results for localized and total void count in each of these methods were directly compared to test samples and linear correlations between the three test …

Pore Elimination Mechanisms During 3d Printing Of Metals, S. Mohammad H. Hojjatzadeh, Niranjan D. Parab, Wentao Yan, Lianyi Chen, For Full List Of Authors, See Publisher's Website.

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser powder bed fusion (LPBF) is a 3D printing technology that can print metal parts with complex geometries without the design constraints of traditional manufacturing routes. However, the parts printed by LPBF normally contain many more pores than those made by conventional methods, which severely deteriorates their properties. Here, by combining in-situ high-speed high-resolution synchrotron x-ray imaging experiments and multi-physics modeling, we unveil the dynamics and mechanisms of pore motion and elimination in the LPBF process. We find that the high thermocapillary force, induced by the high temperature gradient in the laser interaction region, can rapidly eliminate pores from the …

Second-Harmonic Optical Vortex Conversion From Ws₂ Monolayer, Arindam Dasgupta, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Wavelength, polarization and orbital angular momentum of light are important degrees of freedom for processing and encoding information in optical communication. Over the years, the generation and conversion of orbital angular momentum in nonlinear optical media has found many novel applications in the context of optical communication and quantum information processing. With that hindsight, here orbital angular momentum conversion of optical vortices through second-harmonic generation from only one atomically thin WS2 monolayer is demonstrated at room temperature. Moreover, it is shown that the valley-contrasting physics associated with the nonlinear optical selection rule in WS2 monolayer precisely determines the output circular …

Numerical Simulations Of Comprehensive Hydrodynamic Performance Of Darpa Suboff Submarine, Kenshiro Takahashi

Theses and Dissertations

A numerical study of the DARPA SUBOFF model using computational fluid dynamics (CFD) has been presented for developing a CFD application procedure to compute the hydrodynamic performance of underwater vehicles, including submarines. Several configurations, such as bare hull, fairwater, sterns, and/or ringwing-appended hulls, were examined for the straight-ahead, steady translation and turning, and self-propelled conditions. A systematic study was conducted to ensure an adequate computational domain expansion and reasonable prism layer mesh properties for solutions independent of the parameters. The hydrodynamic forces exerted on the hull and the appendages were verified and validated in accordance with a published methodology under …

Application Of Solar Water Heaters For Industrial Use, Lucas T. Atkins

Theses and Dissertations

Solar water heating is a technology that is mainly used for domestic water heating in residential homes. In most applications, the idea is to make a home “off the grid” in that there is no requirement for outside infrastructure or need for energy utility to provide power to this home. This falls in line with the trend of “going green” in an effort to reduce energy use, increase efficiency, or reduce emissions and other harmful byproducts.

This technology can be adapted to reduce the energy costs of industrial manufacturing plants. By eliminating the need for certain sections of a process …