Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

2019

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1 - 30 of 1647

Full-Text Articles in Mechanical Engineering

The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1 Dec 2019

The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1

Tanzania Journal of Engineering and Technology (TJET)

Worldwide, every day human beings generate millions of tons of Faecal Sludge (FS), which is rich in water, nutrients, energy, and organic compounds. Yet FS is not being managed in a way that permits us to derive value from its reuse, while at the same time, millions of farmers struggle with depleted soils and lack of water. In most of the developing countries, energy for cooking is mainly derived from cutting of trees, either as wood or charcoal. Resource recovery and reuse from FS can create livelihoods, enhance food security, support green economies, reduce waste and contribute to cost recovery …


Failure Of High Strength Concrete Under Dynamic Uniaxial Compression, Colin Loeffler Dec 2019

Failure Of High Strength Concrete Under Dynamic Uniaxial Compression, Colin Loeffler

Mechanical Engineering Research Theses and Dissertations

The failure strength of concrete materials has been widely shown to be dependent on experimental parameters such as specimen geometry and strain-rate. The effects of specimen geometry have been shown both theoretically and experimentally to be a result of the quasi-brittle nature of concrete. While the failure strength of concrete has been widely reported to increase significantly when deformed at high strain-rates, the physical mechanisms driving this phenomenon remain the source of debate amongst researchers. This means that constitutive models designed to predict this rate dependent behavior are not based on the real physical mechanisms that drive this behavior but …


Smart Factories, Dumb Policy? Managing Cybersecurity And Data Privacy Risks In The Industrial Internet Of Things, Scott J. Shackelford Dec 2019

Smart Factories, Dumb Policy? Managing Cybersecurity And Data Privacy Risks In The Industrial Internet Of Things, Scott J. Shackelford

Minnesota Journal of Law, Science & Technology

No abstract provided.


Fft Phase Shift Of Water Wave Analysis, Chu-Kuan Lin, Shih-Yu Hsu, Jaw-Guei Lin Dec 2019

Fft Phase Shift Of Water Wave Analysis, Chu-Kuan Lin, Shih-Yu Hsu, Jaw-Guei Lin

Journal of Marine Science and Technology–Taiwan

The fast Fourier transform (FFT) has been accepted as a tool for signal processing. This study conducted a series of numerical experiments using Matlab. By conducting FFT analysis on designated wave trains, the FFT results revealed that an extra phase shift of ��ሺ2�� ��⁄ ሻ , with N representing the number of data points for an i-th wave component, was implicitly added to the analyzed phases during the analysis. When extra phase shifts were subtracted from the analyzed phases of each component, signals could be completely reconstructed in the time domain with an acceptable difference. This study tested component and …


Generalized Ultrasonic Scattering Model For Arbitrary Transducer Configurations, Andrea P. Arguelles, Joseph A. Turner Dec 2019

Generalized Ultrasonic Scattering Model For Arbitrary Transducer Configurations, Andrea P. Arguelles, Joseph A. Turner

Department of Mechanical and Materials Engineering: Faculty Publications

Ultrasonic scattering in polycrystalline media is directly tied to microstructural features. As a result, modeling efforts of scattering from microstructure have been abundant. The inclusion of beam modeling for the ultrasonic transducers greatly simplified the ability to perform quantitative, fully calibrated experiments. In this article, a theoretical scattering model is generalized to allow for arbitrary source and receiver configurations, while accounting for beam behavior through the total propagation path. This extension elucidates the importance and potential of out-of-plane scattering modes in the context of microstructure characterization. The scattering coefficient is explicitly written for the case of statistical isotropy and ellipsoidal …


Acoustic Design Optimization With Isogeometric Analysis And Differential Evolution, Garrett W. Dodgen Dec 2019

Acoustic Design Optimization With Isogeometric Analysis And Differential Evolution, Garrett W. Dodgen

Mechanical Engineering Theses

The objective of this study is to utilize shape optimization to enhance the performance of devices relying on acoustic wave propagation. Particularly, the shape of a horn speaker and an acoustic energy harvester were optimized to enhance their performance at targeted frequencies. High order Isogeometric Analysis (IGA) was performed to estimate the acoustic pressure with minimum geometry and pollution errors [1]. The analysis platform was then combined with Differential Evolution (DE) to optimize the geometry of the horn speaker and energy harvester at a given frequency. These cases effectively demonstrate two applications of Isogeomtric shape optimization for devices relying on …


System And Method For Determining Operating Deflection Shapes Of A Structure Using Optical Techniques, Javad Baqersad Dec 2019

System And Method For Determining Operating Deflection Shapes Of A Structure Using Optical Techniques, Javad Baqersad

Mechanical Engineering Patents

A system for measuring total operating deflection shapes of a structure includes one or more imagers, each including two cameras spaced apart from one another and each oriented and positioned to have corresponding fields of view of a different corresponding section of the structure, with the corresponding sections that may include overlap area of the structure within each of the different sections of the structure. Each of the cameras generates a corresponding data stream, which is communicated to a controller, which is configured to measure the response of the structure to an excitation, such as a vibration or an impulse. …


Impact Of Isolated Atmospheric Aging Processes On The Cloud Condensation Nuclei Activation Of Soot Particles, Franz Friebel, Prem Lobo, David Neubauer, Ulrike Lohmann, Saskia Drossaart Van Dusseldorp, Evelyn Mühlhofer, Amewu A. Mensah Dec 2019

Impact Of Isolated Atmospheric Aging Processes On The Cloud Condensation Nuclei Activation Of Soot Particles, Franz Friebel, Prem Lobo, David Neubauer, Ulrike Lohmann, Saskia Drossaart Van Dusseldorp, Evelyn Mühlhofer, Amewu A. Mensah

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The largest contributors to the uncertainty in assessing the anthropogenic contribution in radiative forcing are the direct and indirect effects of aerosol particles on the Earth's radiative budget. Soot particles are of special interest since their properties can change significantly due to aging processes once they are emitted into the atmosphere. Probably the largest obstacle for the investigation of these processes in the laboratory is the long atmospheric lifetime of 1 week, requiring tailored experiments that cover this time span. This work presents results on the ability of two types of soot, obtained using a miniCAST soot generator, to act …


Synthesis And Connection Of Iridium Hydrogen Evolution Catalyst To Chlorella Vulgaris Photosystem I For Light-Driven Hydrogen Evolution, Anna Ramirez Dec 2019

Synthesis And Connection Of Iridium Hydrogen Evolution Catalyst To Chlorella Vulgaris Photosystem I For Light-Driven Hydrogen Evolution, Anna Ramirez

Honors Program Theses and Projects

Hydrogen gas has been shown to be a promising energy source as options other than fossil fuels are being looked at in the face of anthropogenic climate change. It is known that anthropogenic climate change is caused by the production of greenhouse gases being let into the atmosphere, specifically a common reason for this is the burning of fossil fuels for energy. The overall goal of this project is to design a biochemical hybrid system that will be used to make H 2 gas and does not require the use of fossil fuels. Burning hydrogen as fuel produces only water …


Longitudinal Acoustic Traps: Design, Fabrication, And Evaluation For Biological Applications, Michael Moore Binkley Dec 2019

Longitudinal Acoustic Traps: Design, Fabrication, And Evaluation For Biological Applications, Michael Moore Binkley

McKelvey School of Engineering Graduate Student Theses & Dissertations

Acoustofluidics combine ultrasonic actuation with small-volume microfluidic channels to enable precise, contactless object manipulation for a range of applications from serial chemical processing to blood component separation and single-cell analysis. Micron- to millimeter-scale vibrational waves generate reproducible pressure fields within the microfluidic channels and chambers. By exploiting the material property mismatch between a particle (polymeric and silica beads, cells, etc.) and a suspending fluid, the acoustic radiation force is used to move particles toward regions of low (nodes) or high pressure (antinodes). An understanding of these field-particle interactions is applied to design and implement complicated channel architectures for preferential segregation …


Group A: Asme Student Design Challenge, Dakshi Jindal, Ashley Perry, Ben Liao Dec 2019

Group A: Asme Student Design Challenge, Dakshi Jindal, Ashley Perry, Ben Liao

Mechanical Engineering Design Project Class

This year's student design competition is termed "Building to the Sky." Student teams are required to build a compact engineering system capable of manufacturing a tower made of only standard-sized sheets of paper.


Development Of High-Speed Photoacoustic Imaging Technology And Its Applications In Biomedical Research, Yun He Dec 2019

Development Of High-Speed Photoacoustic Imaging Technology And Its Applications In Biomedical Research, Yun He

McKelvey School of Engineering Graduate Student Theses & Dissertations

Photoacoustic (PA) tomography (PAT) is a novel imaging modality that combines the fine lateral resolution from optical imaging and the deep penetration from ultrasonic imaging, and provides rich optical-absorption–based images. PAT has been widely used in extracting structural and functional information from both ex vivo tissue samples to in vivo animals and humans with different length scales by imaging various endogenous and exogenous contrasts at the ultraviolet to infrared spectrum. For example, hemoglobin in red blood cells is of particular interest in PAT since it is one of the dominant absorbers in tissue at the visible wavelength.The main focus of …


Group E: Improved Greens Harvester, Paige Grittner, Paul Harding, Ned Curran, Jennifer Mata Dec 2019

Group E: Improved Greens Harvester, Paige Grittner, Paul Harding, Ned Curran, Jennifer Mata

Mechanical Engineering Design Project Class

The Improved Greens Harvester is a project designing an improved machine that will be used to harvest crops by our client, EarthDance Organic Farm School in Ferguson, MO. The goal of our design was to provide a simple, easy-to-use, and easyto-fix machine that would cut and collect baby green leaves as the user walks along the plant bed. We first sought to address issue with the client’s current machine including low cutting accuracy, strain on the user’s body, frequent jamming, and low efficiency. Our initial design was a cart design that included: an oscillating blade for cutting, a rotating rope-shaft …


Improved Greens Harvester, Sharon Park, Khalil Clark, Millyn Brieschke Dec 2019

Improved Greens Harvester, Sharon Park, Khalil Clark, Millyn Brieschke

Mechanical Engineering Design Project Class

This paper attempts to provide a prototype of the improved greens harvester. Some inconveniences of the users, including not able to cut greens at a constant length, greens getting clogged in between the brush and the basket, and the need to empty the basket a lot of times. This paper describes problem understanding, concept generation, concept selection, concept embodiment, working prototype, and design refinement. Through these analyses and processes, an improved greens harvester solving the inconveniences is designed. The improved greens harvester has a higher greens harvester with wheels that makes using the harvester less troublesome. Band saw is stuck …


Design Of Efficient Carbon-Based Adsorbents For The Removal Of Organic And Inorganic Water Contaminants, Sayedeh Soroosh Mortazavian Dehkordi Dec 2019

Design Of Efficient Carbon-Based Adsorbents For The Removal Of Organic And Inorganic Water Contaminants, Sayedeh Soroosh Mortazavian Dehkordi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Granular activated carbon (AC) and biochar (BC) are two carbon-based adsorbents commonly used for water and wastewater treatment. However, these adsorbents have drawbacks that suppress their aqueous contaminants removal efficiency. Their major disadvantages are that AC has low selectivity and reusability potential, and BC has a hydrophobic nature.

The scope of this dissertation is to enhance the performance of commonly-used carbon-based adsorbents for the removal of organic and inorganic water contaminants and to understand the interactive mechanism of contaminants’ ions/molecules with adsorbents. Hexavalent chromium (Cr(VI)) and trichloroethylene (TCE) are two types of inorganic and organic water contaminants, respectively, which are …


Ambient Temperature Dependence Of Air-Cooled Condenser Performance And Parameters, Alexander Darr Smith Dec 2019

Ambient Temperature Dependence Of Air-Cooled Condenser Performance And Parameters, Alexander Darr Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Thermoelectric power generation uses 38% of total fresh water withdrawals and majority of that water is used during steam condensation. Air-cooled condensers are an alternative to water-cooled condensers for power generation. Ambient air temperature affects the performance of air-cooled condensers. A small air-cooled condenser was run under the ambient air temperature extremes of Las Vegas in order to examine the system performance and air-side heat transfer parameters. Three different sets of tubes with different surface areas and geometries were studied. The condenser is equipped with several air velocity sensors, thermocouples and thermistors to measure the conditions to develop the air-side …


Cfd Simulation Investigating The Effects Of Groove Geometry On Heat Transfer For Internally Grooved Tubes, Richard Zaven Saroukhanoff Dec 2019

Cfd Simulation Investigating The Effects Of Groove Geometry On Heat Transfer For Internally Grooved Tubes, Richard Zaven Saroukhanoff

UNLV Theses, Dissertations, Professional Papers, and Capstones

This numerical study investigates the thermal performance of internally grooved tubes used in heat exchangers. In order to enhance the performance of heat exchangers, turbulence promoters are inserted along the streamwise flow. The use of inserts, grooves, and augmentations along the axial length of the tube creates disturbances that improve the overall heat transfer due to enhanced fluid mixing and greater surface contact boundary walls. However, the implementation of tube wall augmentations creates an increase in pressure drop across the tube which must be compensated for with additional pumping power for the working fluid. Therefore, in order to analyze the …


Group S- Arliss Project, Preston Bailey, Zach Stelwagon, Cal Reynolds, James Hardy Dec 2019

Group S- Arliss Project, Preston Bailey, Zach Stelwagon, Cal Reynolds, James Hardy

Mechanical Engineering Design Project Class

Our project was the ARLISS competition project, more specifically the second part of the project where the vehicle must survive a drop and drive to a known location over rough desert terrain. We interviewed our professor, Dr. Potter, who had previous experience with the project to understand what was required in our design. The project started with creating concept ideas and deciding on one, which initially was an airplane to avoid designing a landing mechanism and having to drive over rough terrain. However, this design proved to have too many flaws and was scrapped. The new design was a small …


Asme Design Challenge: The Jenga Stacker, Zachary Lin, Alex Chernauskas, Mitch Dorsey, Alex Remmers Dec 2019

Asme Design Challenge: The Jenga Stacker, Zachary Lin, Alex Chernauskas, Mitch Dorsey, Alex Remmers

Mechanical Engineering Design Project Class

The 2020 ASME Design Challenge requires teams to build a compact engineering system capable of manufacturing a tower made exclusively from standard-sized sheets of paper. The validation of the design will include testing for manufacturing speed, height of tower, and ability to support a load. Our senior design project focuses on the stacking mechanism and is designed to stack a 4 in x 4 in tower out of prepared 4 in x 1.5 in x 1.75 in paper boxes from the ground up.


City Of New Smyrna Beach Solar Feasibility Assessment, Florida Solar Energy Center, Charles Withers, Jr. Dec 2019

City Of New Smyrna Beach Solar Feasibility Assessment, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

At the request of the City of New Smyrna Beach, the Florida Solar Energy Center (FSEC) assessed rooftop solar and building energy efficiency improvement potential for 17 city-owned facilities. The intent has been to assist City leaders in identifying opportunities to reduce the City's overall electricity consumption and increase its use of renewable energy.

The FSEC team conducted Level 1 energy audit activities and site assessments including:

On-site assessment

  • Solar feasibility measurements and characterization including orientation, roof shading (adjacent structures, encroaching trees, etc.), available roof area, system output, annualized savings
  • HVAC characterization
  • Lighting survey
  • Occupancy density, schedule, thermostat settings

Post …


Integrated Design Approach For Coronary Stents Using Flexinol Shape Memory Alloy, Matthew Lucci Dec 2019

Integrated Design Approach For Coronary Stents Using Flexinol Shape Memory Alloy, Matthew Lucci

Mechanical Engineering Theses

This research seeks to develop and verify a model for control of the shape memory alloy (SMA) Flexinol and apply such findings to practical application of the material as a platform for bare metal stenting technologies. Utilizing experimental data and material properties, a mathematical model of the thermoelectric contraction behavior of Flexinol wire samples was developed. This model accounted for variable resistance due to the shape memory effect of the Flexinol wire as it experiences a crystalline phase change. It also accounted for the change in the cross-sectional area of the wire as the wire experienced thermal expansion and contraction. …


Experimental Study Of Condensation In A Thermoacoustic Cooler With Various 3d Printed Regenerators Using Water Vapor As The Working Fluid, Aibek Bekkulov, Andrew Luthen, Ben Xu Dec 2019

Experimental Study Of Condensation In A Thermoacoustic Cooler With Various 3d Printed Regenerators Using Water Vapor As The Working Fluid, Aibek Bekkulov, Andrew Luthen, Ben Xu

Mechanical Engineering Faculty Publications

Thermoacoustics (TA) deals with the conversion of heat into sound and vice versa. The device that transfers energy from a low temperature reservoir to a high temperature one by utilizing acoustic work is called TA cooler (TAC). The main components of a typical TAC are a resonator, a porous regenerator (e.g. stack of parallel plates) and two heat exchangers. The thermoacoustic phenomenon takes place in the regenerator where a nonzero temperature gradient is imposed, and interacts with the sound wave. The low temperature at the cold end of TAC can be used to condense water from the humid air and …


3d Chocolate Printer Bed Design, Dean Oken, Jacob Margolin, Ben Hartmann, Sam Grossman Dec 2019

3d Chocolate Printer Bed Design, Dean Oken, Jacob Margolin, Ben Hartmann, Sam Grossman

Mechanical Engineering Design Project Class

The client wished for a device to gain the interest of young undergraduate students into basic thermal science and fluid dynamics concepts. A 3D printer bed was created from concept to prototype design and paired with chocolate dropper teams to complete the project and accomplish the client's goals.


Mems 411 Group L (Fall 2019) - Speedy Seeder Final Report, Michael Morrow, Christopher Nelson, Ross Frame Dec 2019

Mems 411 Group L (Fall 2019) - Speedy Seeder Final Report, Michael Morrow, Christopher Nelson, Ross Frame

Mechanical Engineering Design Project Class

The Speedy Seeder or ”SS” is a device designed to decrease the time it takes to fill one seed plot by hand to roughly sixteen percent of the time. The customer of the SS is EarthDance Organic Farms School. EarthDance fills a large number of plots each year by placing a seed in every single compartment which come in three sizes: 32, 72, and 128 compartments per plot. Filling a single plot by hand can take roughly 8 minutes. The SS makes filling a plot much easier and faster, allowing a single plot to be filled in under 75 seconds. …


Enhanced Heat Transfer Performance By Shape Optimization Of A Non-Axisymmetric Droplet Evaporating On A Heated Micropillar, Haotian Wu Dec 2019

Enhanced Heat Transfer Performance By Shape Optimization Of A Non-Axisymmetric Droplet Evaporating On A Heated Micropillar, Haotian Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Abstract

Enhanced Heat Transfer Performance by Shape Optimization of a Non-axisymmetric Droplet Evaporating on a Heated Micropillar

By

Haotian Wu

Department of Mechanical Engineering and Materials Science

Washington University in St. Louis, 2019

Research Advisor: Professor Damena Agonafer

The stacked multilayer 3D IC structure used in next generation high-powered electronics poses great challenges in dissipating their large heat flux, which causes extreme difficulties for traditional cooling technologies. In response, more advanced two-phase liquid cooling technologies, such as droplet evaporation, which utilizes the latent heat of vaporization to remove excessive heat, have been widely investigated. Compared to traditional single-phase cooling techniques, …


Violin Bow-Hand Prosthetic, Jonathan Smith, Jonathon Azziz, Shawn Pavey Dec 2019

Violin Bow-Hand Prosthetic, Jonathan Smith, Jonathon Azziz, Shawn Pavey

Mechanical Engineering Design Project Class

The violin bow hand prosthetic was designed for a young violin player seeking to upgrade the functionality of his current violin prosthetic device. His current device is rigid, forcing him to play mostly with his shoulder. Since the strength of his wrist was unknown, we designed a prosthetic with enough brace flexibility to enable the user to control the bow motion with his own wrist. We also added an axis of rotation and spring mechanism to supplement this motion and provide him the equivalence of fine finger adjustments. The full design process of the prosthetic is documented in this report, …


Violin Bow-Hand Prosthetic, Ron Hayes Jr, Kc Cook, Romario Lobban, Muriel Drexler Dec 2019

Violin Bow-Hand Prosthetic, Ron Hayes Jr, Kc Cook, Romario Lobban, Muriel Drexler

Mechanical Engineering Design Project Class

The violin bow-hand prosthetic aims to mimic the natural hold and motion of a violinist’s bow-hand. The prosthetic is for a violinist who is missing the majority of their hand, but still has full range of motion in the wrist. Focusing on maintaining a natural playing style greatly influenced the design of the device to be user safe, durable, comfortable, easy to use, inexpensive, and practical. Many of these features were achieved by using 3D printed plastic and foam composites. These materials were selected based on strength and deflection analyses of 3-D simulations performed in SolidWorks and the ease of …


Group M: Arliss Canister Vehicle, Greyson Bourgeois, Eleanor Macklin, Romail Dawani, Rachel Sample Dec 2019

Group M: Arliss Canister Vehicle, Greyson Bourgeois, Eleanor Macklin, Romail Dawani, Rachel Sample

Mechanical Engineering Design Project Class

This project is a dicycle designed for the ARLISS Canister Competition. In this competition, the device is loaded into a rocket which is then launched to about 12000 ft before releasing the device. Then it must safely land and autonomously navigate to a predetermined GPS location on the ground. Due to the fact that this is a mechanical engineering design project and the time restrictions of this class, we focused on the physical aspect of the project, such as building a device that can survive the launch and landing and traverse several kilometers through the desert, forgoing the autonomous navigation …


Effect Of Different Types Of Static Mixer Geometry On Quality Of Microbubble Generation, Tee Wu Yang Dec 2019

Effect Of Different Types Of Static Mixer Geometry On Quality Of Microbubble Generation, Tee Wu Yang

Student Works (2020-2029)

This research project is mainly focused on the impact of different types of static mixer on the quality of microbubble generation. The design of the microbubble generation consists of venturi to allow the air intake by using pressure difference and then different static mixer geometry are tested to investigate the effect on bubble rising time and dissolved oxygen (DO). At the first part of study, the work comprises of the relationship of bubble rising time at different pressures and bubble diameter at different pressures. It has proved that higher pressure will induce small bubble diameter and the bubble rising time …


Third-Eye, Aaron Fassler Dec 2019

Third-Eye, Aaron Fassler

Undergraduate Honors Capstone Projects

The Third-Eye Device is a peripheral device compatible with any firearm equipped with the Picatinny rail system. Its system of a camera attached to the weapon which connects to an eyepiece allows the user to aim the weapon without aiming down the sights. This device is potentially crucial to those who regularly engage in close-quarters combat such as police and military specialists, whose ability to quickly and accurately clear rooms during operations is critical to their safety and the safety of others. The student team was tasked with improving the device, primarily in its survivability in dusty and wet environments, …