Mechanical Engineering Commons^™

Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actuators determine the performance of robotic systems at the most intimate of levels. As a result, much work has been done to assess the performance of different actuator systems. However, biomimetics has not previously been utilized as a pretext for tuning a series elastic actuator system with the purpose of designing an empirical testing platform. Thus, an artificial muscle tendon system has been developed in order to assess the performance of two distinct actuator types: (1) direct current electromagnetic motors and (2) ultrasonic rotary piezoelectric motors. Because the design of the system takes advantage of biomimetic operating principles such as …

Development Of An Exteroceptive Sensor Suite On Unmanned Surface Vessels For Real-Time Classification Of Navigational Markers, Christopher Lloyd Kennedy

Doctoral Dissertations and Master's Theses

This thesis presents the development of an exteroceptive sensor suite for real-time detection and classification of navigational markers on Unmanned Surface Vessels. Three sensors were used to complete this task: a 3D LIDAR and two visible light cameras. First, all LIDAR points were transformed from the sensor’s reference frame to the local frame using a Kalman filter to estimate instantaneous vehicle pose. Next, objects were chosen from the LIDAR data to be classified using either Multivariate Gaussian or Parzen Window Classifiers. Both produce 96% accuracy or better, however, multivariate Gaussian ran considerably faster than the Parzen and was simpler to …

Enhancement Techniques Of Boiling Heat Transfer, Basim Qasim Ali Al-Sukaini

Doctoral Dissertations and Master's Theses

The aim of this study is to investigate pool boiling performance of water under atmospheric pressure by two techniques. The first method is by adding small amounts of surfactants, and the second way is by using structured surfaces.

The first technique is investigated experimentally with environmentally friendly surfactants. The surfactants chosen for the study are an ionic sodium lauryl sulfate (SLS), nonionic ECOSURF™ EH-14, and nonionic ECOSURF™ SA-9. It is observed that adding a small amount of surfactant alters the water boiling phenomenon significantly. Boiling curves for different concentrations are shifted to the left. The wall temperature drops greatly with …

Run-Time Hev Engine-Generator Power-Speed Optimization For Fuel Consumption And Emissions Reduction, Chester Paul Rowe Ii

Doctoral Dissertations and Master's Theses

As fuel economy and emissions standards become more stringent, Plug-in Hybrid Electric Vehicles (PHEV) using series architectures are being increasingly explored. Due to the decoupling of the Internal Combustion Engine (ICE) from the road, the primary control challenge in this architecture is the optimization of an ICE control law. A run-time Genset speed controller is presented for use during the charge-sustaining mode in a Series PHEV to find the optimal operating parameters for a conventional diesel engine coupled to an electric generator in terms of minimized fuel consumption and emissions generation. On board vehicle sensors provide real time data to …

Transient Heat Transfer Between A Magnetocaloric Packed Particle Bed And Stagnant Interstitial Fluid., Michael G. Schroeder 1988-

Electronic Theses and Dissertations

In the field of magnetocaloric heat pumps, many system models have been made. What most of these models lack is heat transfer occurring while there is no fluid motion. It is the objective of this paper to analytically determine and experimentally verify heat transfer with no bulk fluid motion. The addition of a pure dwell period to the typical magnetocaloric cycle was shown to have a positive performance impact in specific conditions. These conditions correspond to regenerators that are heat transfer rate limited in operation. The heat transfer mechanism for this particular case was shown to be pure conduction via …

Wear Resistant Polydopamine/Ptfe Nanoparticle Composite Coating For Dry Lubrication Applications, Samuel George Beckford

Graduate Theses and Dissertations

This dissertation presents an investigation into the effect of nanoparticle fillers and a polydopamine adhesive primer on the tribological performance of thin PTFE films. The principal objective of this investigation was to reduce wear in PTFE films, an issue which precludes the use of PTFE films in tribological applications requiring high durability. The friction and wear of the composite films were evaluated using a ball-on-flat configuration in linear reciprocating motion. It was found that the use of a polydopamine adhesive primer reduces the wear of PTFE films more than 600 times. X-ray photoelectron spectroscopy (XPS) results show that a tenacious …

Highly Transparent, Self-Cleaning, And Antireflective Nanoparticle Coatings, Corey Seth Thompson

Graduate Theses and Dissertations

Current solar panel technologies require a sheet of glass to serve as both mechanical support and to protect the cells from the environment. The reflection from the glass sheet can reflect up to 8% of the incident light, reducing the power output of the panel. Antireflective coatings can be used to allow more light to enter the panel to be converted into usable electricity. However, no solid thin film materials exhibit a low enough index of refraction to serve as antireflective coatings for common solar glass. The main goal of this research was to investigate the self-cleaning, antifogging, and antireflective …

Thermo-Physical Property Models And Effect On Heat Pipe Modelling, Devakar Dhingra

All Theses

Heat transfer devices find applications in various aspects of life. Be it residential, commercial or industrial application, efficient heat transfer is a challenge to all. Other than geometric design considerations and wick selection, the optimization of heat transfer in the heat pipe also depends on fluid selection. Heat pipe technology has proven to work efficiently with properly selected thermal fluid, from cryogenic temperatures to very high temperatures. Higher heat transfer ability through small temperature differences makes the heat pipe an efficient technology. Hence, it can be stated that selecting a proper working fluid enhances the heat transfer performance of a …

Thermo-Mechanical Characterization Of Glass And Its Effect On Predictions Of Stress State, Birefringence And Fracture In Precision Glass Molded Lenses, Dhananjay Joshi

All Dissertations

The Precision Glass Molding (PGM) process was established as an economical and sustainable option for the production of aspherical glass optics to satisfy the increased industrial demand. Applications of precision molded aspherical lenses range from consumer electronics products such as cell phone cameras to defense and medical systems. An aspherical lens can eliminate the spherical and optical aberrations as compared to a spherical lens thus making the lens system more compact and lighter. In spite of being a clean and environmentally friendly process, the lens molding operation suffers from a few drawbacks such as lens profile deviation, stress birefringence/refractive index …

Modular And Cooperative Medical Devices And Related Systems And Methods, Shane M. Farritor, Mark Rentschler, Amy Lehman

Department of Mechanical and Materials Engineering: Faculty Publications

The various embodiments disclosed herein relate to modular medical devices, including various devices with detachable modular components and various devices with pivotally attached modular components. Additional embodiments relate to procedures in which various of the devices are used cooperatively. Certain embodiments of the medical devices are robotic in vivo devices.

Anisotropic Complementary Acoustic Metamaterial For Canceling Out Aberrating Layers, Chen Shen, Jun Xu, Nicholas X. Fang, Yun Jing

Henry M. Rowan College of Engineering Departmental Research

In this paper, we investigate a type of anisotropic, acoustic complementary metamaterial (CMM) and its application in restoring acoustic fields distorted by aberrating layers. The proposed quasi two-dimensional (2D), nonresonant CMM consists of unit cells formed by membranes and side branches with open ends. Simultaneously, anisotropic and negative density is achieved by assigning membranes facing each direction ( x and y directions) different thicknesses, while the compressibility is tuned by the side branches. Numerical examples demonstrate that the CMM, when placed adjacent to a strongly aberrating layer, could acoustically cancel out that aberrating layer. This leads to dramatically reduced acoustic …

Modification Of A Single-Molecule Afm Probe With Highly Defined Surface Functionality, Fei Long, Bin Cao, Ashok Khanal, Shiyue Fang, Reza Shahbazian-Yassar

Michigan Tech Publications

Single-molecule force spectroscopy with an atomic force microscope has been widely used to study inter- and intramolecular interactions. To obtain data consistent with single molecular events, a well-defined method is critical to limit the number of molecules at the apex of an AFM probe to one or to a few. In this paper, we demonstrate an easy method for single-molecule probe modification by using the Cu-catalyzed alkyne–azide cycloaddition reaction. Excess terminal alkynes were covalently attached to the probe, and a bi-functional molecule containing an azide at one end and a carboxylic acid at the other was dissolved in the reaction …

Pseudo-Rigid-Body Models For Approximating Spatial Compliant Mechanisms Of Rectangular Cross Section, Issa Ailenid Ramirez

USF Tampa Graduate Theses and Dissertations

The objective of the dissertation is to develop and describe kinematic models (Pseudo-Rigid-Body Models) for approximating large-deflection of spatial (3D) cantilever beams that undergo multiple bending motions thru end-moment loading. Those models enable efficient design of compliant mechanisms, because they simply and accurately represent the bending and stiffness of compliant beams.

To accomplish this goal, the approach can be divided into three stages: development of the governing equations of a flexible cantilever beam, development of a PRBM for axisymmetric cantilever beams and the development of spatial PRBMs for rectangular cross-section beam with multiple end moments.

The governing equations of a …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Society of Manufacturing Engineers (SME) Distinguished Faculty Advisor Award

Inverse Volume-Of-Fluid Meshless Method For Efficient Non-Destructive Thermographic Evaluation, Hussein Awad Kurdi Saad

Doctoral Dissertations and Master's Theses

A novel computational tool based in the Localized Radial-basis Function (RBF) Collocation (LRC) Meshless method coupled with a Volume-of-Fluid (VoF) scheme capable of accurately and efficiently solving transient multi-dimensional heat conduction problems in composite and heterogeneous media is formulated and implemented. While the LRC Meshless method lends its inherent advantages of spectral convergence and ease of automation, the VoF scheme allows to effectively and efficiently simulate the location, size, and shape of cavities, voids, inclusions, defects, or de-attachments in the conducting media without the need to regenerate point distributions, boundaries, or interpolation matrices. To this end, the Inverse Geometric problem …

Synthesis And Formation Mechanism Of Cuins2 Nanocrystals With A Tunable Phase, Chao Yu, Linlin Zhang, Long Tian, Dan Liu, Fanglin Chen, Cheng Wang

Faculty Publications

Chalcopyrite CuInS₂ (CIS) hierarchical structures composed of nanoflakes with a thickness of about 5 nm were synthesized by a facial solvothermal method. The thermodynamically metastable wurtzite phase CIS would be obtained by using InCl₃ instead of In(NO₃)₃ as In precursor. The effects of the In precursor and the volume of concentrated HCl aqueous solution on the phases and morphologies of CIS nanocrystals have been systematically investigated. Experimental results indicated that the obtained phases of CIS nanocrystals were predominantly determined by precursor-induced intermediate products. The photocatalytic properties of chalcopyrite and wurtzite CIS in visible-light-driven degradation of …

Thermal Assessment Of A Latent-Heat Energy Storage Module During Melting And Freezing For Solar Energy Applications, Antonio Miguel Ramos Archibold

USF Tampa Graduate Theses and Dissertations

Capital investment reduction, exergetic efficiency improvement and material compatibility issues have been identified as the primary techno-economic challenges associated, with the near-term development and deployment of thermal energy storage (TES) in commercial-scale concentrating solar power plants. Three TES techniques have gained attention in the solar energy research community as possible candidates to reduce the cost of solar-generated electricity, namely (1) sensible heat storage, (2) latent heat (tank filled with phase change materials (PCMs) or encapsulated PCMs packed in a vessel) and (3) thermochemical storage. Among these the PCM macro-encapsulation approach seems to be one of the most-promising methods because of …

Exploration Of Electrodeposition Of Aluminum-Nickel Alloys And Multilayers In Organic Chloroaluminate Ionic Liquids, Ammar Bin Waqar

USF Tampa Graduate Theses and Dissertations

Aluminum-nickel (Al-Ni) alloys and Al/Ni bilayers were successfully electrodeposited from AlCl₃-EMIM-NiCl₂ electrolyte at room temperature. Dissolution of NiCl₂ was shown to be favorable in Lewis basic (with molar ratio of AlCl₃ < 0.5) AlCl₃-EMIM solution. The use of electrochemically active Cu working electrode as opposed to inert W induced additional Cu oxidation and dissolution in the cyclic voltammetry scan. The reduction potentials of Al and Ni were found to be ~ – 0.3 and 0.15 V vs. Al/Al³⁺ respectively. Increasing [NiCl₂] in the electrolyte leads to an increase of Ni concentration in the …

Spanning The Complexity Chasm: A Research Approach To Move From Simple To Complex Engineering Systems, Vimal Viswanathan, Julie Linsey

Faculty Publications, Mechanical Engineering

A multistudy approach is presented that allows design thinking of complex systems to be studied by triangulating causal controlled lab findings with coded data from more complex products. A case study illustration of this approach is provided. During the conceptual design of engineering systems, designers face many cognitive challenges, including design fixation, errors in their mental models, and the sunk cost effect. These factors need to be mitigated for the generation of effective ideas. Understanding the effects of these challenges in a realistic and complex engineering system is especially difficult due to a variety of factors influencing the results. Studying …

Cavitation In Vial Drop Subjected To Mechanical Shock, Houman Babazadehrokni

Electronic Theses and Dissertations

Cavitation is a phenomenon that occurs when the local pressure falls down below the critical pressure. Previous work from the Randolph lab demonstrated that protein aggregates can form when a vial of therapeutic solution is dropped onto a hard surface. The process by which this occurs is most likely shock induced cavitation. During this process, hot spots can be created with temperatures and pressures reaching thousands of Kelvin and hundreds of atmospheres, respectively, leading to degradation of protein therapeutics. This work will extend previous efforts by exploring differences generated by change in vial materials, solutions, drop methods and fill volumes. …

Multi-Modal, Surface-Focused Anticoagulation Using Poly-2-Methoxyethylacrylate Polymer Grafts And Surface Nitric Oxide Release, Surbhi Gupta, Kagya Amoako, Ahmed Suhaib, Keith E. Cook

Mechanical and Industrial Engineering Faculty Publications

This study examines platelet adhesion on surfaces that combine coatings to limit protein adsorption along with “anti-platelet” nitric oxide (NO) release. Uncoated and poly-2-methoxyethylacrylate (PMEA) coated, gas permeable polypropylene (PP) membranes were placed in a bioreactor to separate plasma and gas flows. Nitrogen with 100/500/1000 ppm of NO was supplied to the gas side as a proof of concept. On the plasma side, platelet rich plasma (PRP, 1 × 108 cell/mL) was recirculated at low (60)/high (300) flows (mL/min). After 8 hours, adsorbed platelets on PP was quantified via a lactate dehydrogenase assay. Compared to plain PP, the PMEA coating …

Vulnerability Assessment And Re-Routing Of Freight Trains Under Disruptions: A Coal Supply Chain Network Application, Ridvan Gedik, Hugh Medal, Chase Rainwater, Edward A. Pohl, Scott J. Mason

Mechanical and Industrial Engineering Faculty Publications

In this paper, we present a two-stage mixed integer programming (MIP) interdiction model in which an interdictor chooses a limited amount of elements to attack first on a given network, and then an operator dispatches trains through the residual network. Our MIP model explicitly incorporates discrete unit flows of trains on the rail network with time-variant capacities. A real coal rail transportation network is used in order to generate scenarios to provide tactical and operational level vulnerability assessment analysis including rerouting decisions, travel and delay costs analysis, and the frequency of interdictions of facilities for the dynamic rail system.

Workspace Analysis Of A Linear Delta Robot: Calculating The Inscribed Radius, Michael Louis Pauly

Graduate Theses - Mechanical Engineering

One of the most important traits of a robotic manipulator is its work envelope, the space in which the robot can position its end effector. Parallel manipulators, while generally faster, are restricted by smaller work envelopes [1]. As such, understanding the parameters defining a physical robot’s work envelope is essential to the optimal design, selection, and use of robotic parallel manipulators. A Linear Delta Robot (LDR) is a type of parallel manipulator in which three prismatic joints move separate arms which connect to a single triangular end plate [2]. In this study, general inverse kinematics were derived for a linear …

Assessment Of Noise-Induced Annoyance By Tones In Noise From Building Mechanical Systems, Joonhee Lee, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Prominent tones in noise generated by mechanical equipment in buildings can cause complaints from occupants in buildings. The ISO 1996-2 and ANSI S1.13 standards describe methodologies and metrics to quantify tonality perception, but the influence of tones in noise on human annoyance and performance is not fully understood yet. This paper investigates annoyance responses of humans while exposed to background noise with tonal components. Twenty participants completed digit span tasks while exposed to noise signals with differing levels of tones and overall loudness. Subjects were also asked to rate their annoyance after completing tasks under each noise signal. The subjective …

The Icon Horn Loudspeaker, Vincent Phan

Mechanical Engineering

A horn loudspeaker in layperson terms is essentially taking a megaphone and integrating it into a standard speaker. Similar to a cheerleader yelling into a megaphone, the horn loudspeaker will amplify the sound from the speaker with no additional power needed. Using standard speaker horn theory, the geometry of the “megaphone” can be engineered to tune the acoustic performance tailored to loudness and/or specific acoustics frequencies. The horn contours are similar to traditional orchestra instruments such as the French horn, trumpet, and tuba. The iconic beauty of a horn married with the quantitative engineering theory creates an aesthetic yet functional …

Direct Numerical Simulations Of Non-Premixed Ethylene–Air Flames: Local Flame Extinction Criterion, Vivien R. Lecoustre, Paul G. Grias, Somesh P. Roy, Zhaoyu Luo, Dan C. Haworth, Hong G. Im, Tianfeng F. Lui, Arnaud Trouvé

Mechanical Engineering Faculty Research and Publications

Direct Numerical Simulations (DNS) of ethylene/air diffusion flame extinctions in decaying two-dimensional turbulence were performed. A Damköhler-number-based flame extinction criterion as provided by classical large activation energy asymptotic (AEA) theory is assessed for its validity in predicting flame extinction and compared to one based on Chemical Explosive Mode Analysis (CEMA) of the detailed chemistry. The DNS code solves compressible flow conservation equations using high order finite difference and explicit time integration schemes. The ethylene/air chemistry is simulated with a reduced mechanism that is generated based on the directed relation graph (DRG) based methods along with stiffness removal. The numerical configuration …

Biphilic Nanoporous Surfaces Enabled Exceptional Drag Reduction And Capillary Evaporation Enhancement, Xianming Dai, Fanghao Yang, Ronggui Yang, Xinyu Huang, William A. Rigdon, Xiaodong Li, Chen Li

Faculty Publications

Simultaneously achieving drag reduction and capillary evaporation enhancement is highly desired but challenging because of the trade-off between two distinct hydrophobic and hydrophilic wettabilities. Here, we report a strategy to synthesize nanoscale biphilic surfaces to endow exceptional drag reduction through creating a unique slip boundary condition and fast capillary wetting by inducing nanoscopic hydrophilic areas. The biphilic nanoporous surfaces are synthesized by decorating hydrophilic functional groups on hydrophobic pristine multiwalled carbon nanotubes. We demonstrate that the carbon nanotube-enabled biphilic nanoporous surfaces lead to a 63.1% reduction of the friction coefficient, a 61.7% wetting speed improvement, and up to 158.6% enhancement …

Solid Waste As Renewable Source Of Energy: Current And Future Possibility In Libya, Tarek A. Hamad, Abdulhakim A. Agll, Yousif M. Hamad, John W. Sheffield

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Solid waste holds the greatest potential as biomass source in Libya. The rapid expansion of industry has led to increased urbanization and growing population. These factors have dramatically increased the amount of MSW (municipal solid waste) generated in Libya. However, issues related to environmentally sound MSW management - including waste decrease and clearance - have not been addressed sufficiently. This study presents an overview on solid waste that can be used as a source of bioenergy in Libya including MSW, ISW (industrial solid waste), and HSW (health care wastes) as biomass sources. The management of solid waste and valorization is …

Study Of Energy Recovery And Power Generation From Alternative Energy Source, Abdulhakim Amer A. Agll, Yousif M. Hamad, Tarek A. Hamad, John W. Sheffield

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The energy requirement pattern of world is growing up and developing technology. The available sources, while exhausting and not friendly to the environment, are highly used. Looking at partial supply and different options of environment problems associated with usage, renewable energy sources are getting attention. MSW (Municipal solid waste) composition data had been collected from 1997 to 2009, in Benghazi Libya, to evaluate the waste enthalpy. An incinerator with capacity of 47,250 kg/h was confirmed to burn all the quantity of waste generated by the city through the next 15 years. Initial study was performed to investigate energy flow and …

Fano Resonances Realized In Thz Metamaterials Composed Of Continuous Metallic Wires And Split Ring Resonators, Z. Li, S. Cakmakyapan, B. Butun, C. Daskalaki, S. Tzortzakis, Xiaodong Yang, E. Ozbay

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.