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2017

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Articles 151 - 180 of 1379

Full-Text Articles in Mechanical Engineering

Pollution Prevention In The Great Lakes Basin: Working With Pulp & Paper Manufacturers, Eugene Park Nov 2017

Pollution Prevention In The Great Lakes Basin: Working With Pulp & Paper Manufacturers, Eugene Park

Journal of Environmental Sustainability

In response to growing concerns over persistent toxic substances in the Great Lakes, new initiatives are in place to address and mitigate pollutant loadings to these large natural waterbodies. With support from the U.S. Environmental Protection Agency and New York Department of Environmental Conservation, the New York State Pollution Prevention Institute (NYSP2I) worked with pulp & paper companies in the Great Lakes Basin in an effort to find solutions to reduce environmental impacts from this industry sector. Based on currently available EPA toolkits, NYSP2I developed and utilized an assessment tool called Lean, Energy, and Environment (LE2). Five different paper manufacturers …


Development Mems Acoustic Emission Sensors, Adrian Enrique Avila Gomez Nov 2017

Development Mems Acoustic Emission Sensors, Adrian Enrique Avila Gomez

USF Tampa Graduate Theses and Dissertations

The purpose of this research is to develop MEMS based acoustic emission sensors for structural health monitoring. Acoustic emission (AE) is a well-established nondestructive testing technique that is typically used to monitor for fatigue cracks in structures, leaks in pressurized systems, damages in composite materials or impacts. This technology can offer a precise evaluation of structural conditions and allow identification of imminent failures or minor failures that can be addressed by planned maintenances routines. AE causes a burst of ultrasonic energy that is measured as high frequency surface vibrations (30 kHz to 1 MHz) generated by transient elastic waves that …


A Multi-Scale Approach For Modeling Shock Ignition And Burn Of Granular Hmx, Pratap Thamanna Rao Nov 2017

A Multi-Scale Approach For Modeling Shock Ignition And Burn Of Granular Hmx, Pratap Thamanna Rao

LSU Doctoral Dissertations

Deflagration-to-detonation transition (DDT) in confined, low-density granular HMX (65%-85% Theoretical Maximum Density, TMD) occurs by a complex mechanism that involves compaction shock interactions within the material. Piston driven DDT experiments indicate that detonation is abruptly triggered by the interaction of a strong burn-supported secondary shock and a piston-supported primary (input) shock, where the nature of the interaction depends on initial packing density and primary shock strength. These interactions influence transition by affecting hot-spot formation within the micro-structure during pore collapse. In this study, meso-scale simulations of hot-spot formation in shock loaded granular HMX are used to guide the development of …


Tensile Experimentation Of Structural Aluminum Studying Void Growth, Scott Gampert Nov 2017

Tensile Experimentation Of Structural Aluminum Studying Void Growth, Scott Gampert

Mechanical Engineering ETDs

Uni-axial tensile tests were conducted on multiple dog-bone shaped poly-crystalline Aluminum specimens. The goal for this study was to understand the effects of voiding in structural aluminum and how voids grow under tension. The voids were represented by simply drilling and reaming one or more holes in varying patterns in the center of the sample. The testing clearly showed that the different hole patterns affect the area growth of voids. It also compares the developmental growth of a plasticity zone around samples with one hole to a previous study done with a different specimen shape(Ray,2003). In order to look at …


Reaching In Clutter With Whole-Arm Tactile Sensing, Advait Jain, Marc D. Killpack, Aaron Edsinger, Charles Kemp Nov 2017

Reaching In Clutter With Whole-Arm Tactile Sensing, Advait Jain, Marc D. Killpack, Aaron Edsinger, Charles Kemp

Faculty Publications

Clutter creates challenges for robot manipulation, including a lack of non-contact trajectories and reduced visibility for line-of-sight sensors. We demonstrate that robots can use whole-arm tactile sensing to perceive clutter and maneuver within it, while keeping contact forces low. We first present our approach to manipulation, which emphasizes the benefits of making contact across the entire manipulator and assumes the manipulator has low-stiffness actuation and tactile sensing across its entire surface. We then present a novel controller that exploits these assumptions. The controller only requires haptic sensing, handles multiple contacts, and does not need an explicit model of the environment …


Multiple Consecutive Recapture Of Rigid Nanoparticles Using A Solid-State Nanopore Sensor, Jungsoo Lee Nov 2017

Multiple Consecutive Recapture Of Rigid Nanoparticles Using A Solid-State Nanopore Sensor, Jungsoo Lee

Mechanical Engineering Research Theses and Dissertations

Solid‐state nanopore sensors have been used to measure the size of a nanoparticle by applying a resistive pulse sensing technique. Previously, the size distribution of the population pool could be investigated utilizing data from a single translocation, however, the accuracy of the distribution is limited due to the lack of repeated data. In this study, we characterized polystyrene nanobeads utilizing single particle recapture techniques, which provide a better statistical estimate of the size distribution than that of single sampling techniques. The pulses and translocation times of two different sized nanobeads (80 nm and 125 nm in diameter) were acquired repeatedly …


Development, Energy, And Climate Change Policy: Enabling Sustainable Development Through Access To Energy, Robert J. Brecha Nov 2017

Development, Energy, And Climate Change Policy: Enabling Sustainable Development Through Access To Energy, Robert J. Brecha

Biennial Conference: The Social Practice of Human Rights

Human rights, human development, and climate change clearly overlap in many ways. Development, as quantified by the Human Development Index (HDI), for example, has historically been strongly correlated with energy consumption. This fact is recognized in Sustainable Development Goal (SDG) 7, to “ensure access to affordable, reliable, sustainable and modern energy for all.” Currently the world is in the midst of a large wave of human migration, much of it involuntary and due to stymied development opportunities as well as political upheaval. Climate change will become, or already is, an exacerbating factor in migration dynamics.

A pertinent question is how …


Synthesis, Characterization, And Application Of Molybdenum Oxide Nanomaterials, Michael S. Mccrory Nov 2017

Synthesis, Characterization, And Application Of Molybdenum Oxide Nanomaterials, Michael S. Mccrory

USF Tampa Graduate Theses and Dissertations

Nanostructured molybdenum trioxide (MoO3) was synthesized and used as a precursor in a comparative study, along with commercial MoO3, to synthesize molybdenum dioxide (MoO2) nanoparticles. Scanning electron microscope (SEM) images revealed the particles to be approximately 30-50 nm in diameter. X-ray diffraction (XRD) confirmed MoO3 was fully reduced to MoO2 in all cases. Time dependent experiments showed that within two hours no traces of MoO3 are present. All of the experiments showed the materials were excellent absorbent materials, as well as photocatalysts. Both MoO2 materials performed almost exactly the same, …


Universality Of Local Dissipation Scales In Turbulent Boundary Layer Flows With And Without Free-Stream Turbulence, Sabah F. H. Alhamdi, Sean C. C. Bailey Nov 2017

Universality Of Local Dissipation Scales In Turbulent Boundary Layer Flows With And Without Free-Stream Turbulence, Sabah F. H. Alhamdi, Sean C. C. Bailey

Mechanical Engineering Faculty Publications

Measurements of the small-scale dissipation statistics of turbulent boundary layer flows with and without free-stream turbulence are reported for Reτ ≈ 1000 (Reθ ≈ 2000). The scaling of the dissipation scale distribution is examined in these two boundary conditions. Results demonstrated that the local large-scale Reynolds number based on the measured longitudinal integral length scale fails to properly normalize the dissipation scale distribution near the wall in these two free-stream conditions due to the imperfect characterization of the upper bound of the inertial cascade by the integral length scale. A surrogate found from turbulent kinetic energy and …


Experimental Measurement Of Residual Stress And Distortion In Additively Manufactured Stainless Steel Components With Various Dimensions, M. Ghasri-Khouzani, H. Peng, R. Rogge, R. Attardo, P. Ostiguy, J. Neidig, R. Billo, D. Hoelzle, M. R. Shankar Nov 2017

Experimental Measurement Of Residual Stress And Distortion In Additively Manufactured Stainless Steel Components With Various Dimensions, M. Ghasri-Khouzani, H. Peng, R. Rogge, R. Attardo, P. Ostiguy, J. Neidig, R. Billo, D. Hoelzle, M. R. Shankar

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Disk-shaped 316L stainless steel parts with various diameters and heights were additively manufactured using a direct metal laser sintering (DMLS) technique. Neutron diffraction was used to profile the residual stresses in the samples before and after removal of the build plate and support structures. Moreover, distortion level of the parts before and after the removal was quantified using a coordinate measuring machine (CMM). Large tensile in-plane stresses (up to ≈ 400 MPa) were measured near the as-built disk top surfaces, where the stress magnitude decreased from the disk center to the edges. The stress gradient was steeper for the disks …


Computational Sensitivity Investigation Of Hydrogel Injection Characteristics For Myocardial Support, Hua Wang, Christopher B. Rodell, Madonna E. Lee, Neville N. Dusaj, Joseph H. Gorman Iii, Jason A. Burdick, Robert C. Gorman, Jonathan F. Wenk Nov 2017

Computational Sensitivity Investigation Of Hydrogel Injection Characteristics For Myocardial Support, Hua Wang, Christopher B. Rodell, Madonna E. Lee, Neville N. Dusaj, Joseph H. Gorman Iii, Jason A. Burdick, Robert C. Gorman, Jonathan F. Wenk

Mechanical Engineering Faculty Publications

Biomaterial injection is a potential new therapy for augmenting ventricular mechanics after myocardial infarction (MI). Recent in vivo studies have demonstrated that hydrogel injections can mitigate the adverse remodeling due to MI. More importantly, the material properties of these injections influence the efficacy of the therapy. The goal of the current study is to explore the interrelated effects of injection stiffness and injection volume on diastolic ventricular wall stress and thickness. To achieve this, finite element models were constructed with different hydrogel injection volumes (150 µL and 300 µL), where the modulus was assessed over a range of 0.1 kPa …


Method For Single Crystal Growth Of Photovoltaic Perovskite Material And Devices, Jinsong Huang, Qingfeng Dong Nov 2017

Method For Single Crystal Growth Of Photovoltaic Perovskite Material And Devices, Jinsong Huang, Qingfeng Dong

Department of Mechanical and Materials Engineering: Faculty Publications

Systems and methods for perovskite single crystal growth include using a low temperature solution process that employs a temperature gradient in a perovskite solution in a container , also including at least one small perovskite single crystal , and a substrate in the solution upon which substrate a perovskite crystal nucleates and grows , in part due to the temperature gradient in the solution and in part due to a temperature gradient in the substrate . For example , a top portion of the substrate external to the solution may be cooled .


Rehabilitating Asymmetric Gait Using Asymmetry, Tyagi Ramakrishnan Nov 2017

Rehabilitating Asymmetric Gait Using Asymmetry, Tyagi Ramakrishnan

USF Tampa Graduate Theses and Dissertations

Human gait is a complex process that involves the coordination of the central nervous and muscular systems. A disruption to the either system results in the impairment of a person’s ability to walk. Impairments can be caused by neurological disorders such as stroke and physical conditions like amputation. There is not a standardized method to quantitatively assess the gait asymmetry of affected subjects. The purpose of this research is to understand the fundamental aspects of asymmetrical effects on the human body and improve rehabilitation techniques and devices. This research takes an interdisciplinary approach to address the limitations with current rehabilitation …


Friction Stir Welding Manufacturing Advancement By On-Line High Temperature Phased Array Ultrasonic Testing And Correlation Of Process Parameters To Joint Quality, Daniel James Huggett Nov 2017

Friction Stir Welding Manufacturing Advancement By On-Line High Temperature Phased Array Ultrasonic Testing And Correlation Of Process Parameters To Joint Quality, Daniel James Huggett

LSU Doctoral Dissertations

Welding, a manufacturing process for joining, is widely employed in aerospace, aeronautical, maritime, nuclear, and automotive industries. Optimizing these techniques are paramount to continue the development of technologically advanced structures and vehicles. In this work, the manufacturing technique of friction stir welding (FSW) with aluminum alloy (AA) 2219-T87 is investigated to improve understanding of the process and advance manufacturing efficiency. AAs are widely employed in aerospace applications due to their notable strength and ductility. The extension of good strength and ductility to cryogenic temperatures make AAs suitable for rocket oxidizer and fuel tankage. AA-2219, a descendent of the original duralumin …


Advanced Multi-Speed Transmissions And Their Effect On Fuel Economy, Durability And Reliability, Sean Boyle Nov 2017

Advanced Multi-Speed Transmissions And Their Effect On Fuel Economy, Durability And Reliability, Sean Boyle

ASA Multidisciplinary Research Symposium

In a challenge to meet the high corporate average fuel economy (CAFE), manufacturers are using transmissions with 8, 9, and 10 speeds. This oral presentation addresses vehicle fuel economy impact with advanced multi-speed transmissions and also forecasts the reliability and durability when compared to a conventional 5 and 6-speed transmission.


A Strategic Development Of Alternative Fuel Initiation And Its Adaptation In A Developing Country : A Feasibility Study On Methanol Fuelled Domestic Passenger Ships In Indonesia, Eko Maja Priyanto Nov 2017

A Strategic Development Of Alternative Fuel Initiation And Its Adaptation In A Developing Country : A Feasibility Study On Methanol Fuelled Domestic Passenger Ships In Indonesia, Eko Maja Priyanto

World Maritime University Dissertations

No abstract provided.


A Decision Support System For Ship’S Energy Efficient Operation : Based On Artificial Neural Network Method, Yasser Bayoumy Abdelwahab Farag Nov 2017

A Decision Support System For Ship’S Energy Efficient Operation : Based On Artificial Neural Network Method, Yasser Bayoumy Abdelwahab Farag

World Maritime University Dissertations

No abstract provided.


Optimising Energy Efficiency : Split Incentives In The Context Of The Implementation Of Seemp, Edwin Nii Oduah Mensah Nov 2017

Optimising Energy Efficiency : Split Incentives In The Context Of The Implementation Of Seemp, Edwin Nii Oduah Mensah

World Maritime University Dissertations

No abstract provided.


Analytical Assessment Of Port Energy Efficiency And Management . : A Case Study Of The Kenya Ports Authority, Maryam Mohamed Kidere Nov 2017

Analytical Assessment Of Port Energy Efficiency And Management . : A Case Study Of The Kenya Ports Authority, Maryam Mohamed Kidere

World Maritime University Dissertations

No abstract provided.


Large Area Sintering Test Platform Design And Preliminary Study On Cross Sectional Resolution, Christopher J. Gardiner Nov 2017

Large Area Sintering Test Platform Design And Preliminary Study On Cross Sectional Resolution, Christopher J. Gardiner

USF Tampa Graduate Theses and Dissertations

Additive manufacturing involves the layer-wise patterned addition of material to create 3D parts, allowing for parts with complex geometries that traditional subtractive manufacturing processes cannot create, while offering good value for low run production parts by eliminating the cost of tooling. Large Area Sintering is a form of powder based additive manufacturing where entire layer cross sections are heated and fused in a single continuous exposure process. This layer by layer powder sintering process is similar to selective laser sintering, but by heating the cross section at a slower and controllable rate there is an opportunity to achieve tighter control …


Medium Duty Gas-Turbine Engine Blade Removal Tool, Elliott James Greb, Jacob Thomas Syage, Kellen Thomas Field Nov 2017

Medium Duty Gas-Turbine Engine Blade Removal Tool, Elliott James Greb, Jacob Thomas Syage, Kellen Thomas Field

Mechanical Engineering

Solar Turbines Incorporated sponsored a team of three Cal Poly Undergraduate Mechanical Engineering students to design, manufacture, prototype, and test a tool for the removal of turbine blades from their respective disk assembly without damaging the disk itself. The tool was developed for Solar’s industrial gas turbine engines. The tool complies with all OSHA and Solar Turbines safety and engineering constraints, and was designed for use in a shop facility. The tool was made adaptable for geometric variances in multiple turbine rotor disk stages, and requires no more than one technician to operate using a maximum of two shop resources. …


Hydrodynamic And Thermal Effects Of Sub-Critical Heating On Superhydrophobic Surfaces And Microchannels, Adam M. Cowley Nov 2017

Hydrodynamic And Thermal Effects Of Sub-Critical Heating On Superhydrophobic Surfaces And Microchannels, Adam M. Cowley

Theses and Dissertations

This dissertation focuses on the effects of heating on superhydrophobic (SHPo) surfaces. The work is divided into two main categories: heat transfer without mass transfer and heat transfer in conjunction with mass transfer. Numerical methods are used to explore the prior while experimental methods are utilized for the latter. The numerical work explores convective heat transfer in SHPo parallel plate microchannels and is separated into two stand-alone chapters that have been published archivally. The first considers surfaces with a rib/cavity structure and the second considers surfaces patterned with a square lattice of square posts. Laminar, fully developed, steady flow with …


Anchoring And Stiffening Techniques For Portable Concrete Barriers, Surajkumar Bhakta Nov 2017

Anchoring And Stiffening Techniques For Portable Concrete Barriers, Surajkumar Bhakta

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Portable concrete barrier (PCB) systems are utilized on federal and state highways in circumstances such as placing adjacent to vertical drop-offs and in construction zones. PCB systems are most commonly used in a free-standing configuration, which are known to have relatively large deflections when impacted. Large deflections are undesirable when dealing with limited space. In order to allow PCBs to be used in space restricted locations, seven PCB anchoring and stiffening techniques were tested and evaluated as per Manual for Assessing Safety Hardware (MASH) testing standards. Results will allow the New Jersey Department of Transportation to update guidance for their …


Broadband Infrared Absorbers With Stacked Double Chromium Ring Resonators, H. Deng, L. Stan, D. Czaplewski, Jie Gao, Xiaodong Yang Nov 2017

Broadband Infrared Absorbers With Stacked Double Chromium Ring Resonators, H. Deng, L. Stan, D. Czaplewski, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Maritime Object Detection, Tracking, And Classification Using Lidar And Vision-Based Sensor Fusion, David John Thompson Nov 2017

Maritime Object Detection, Tracking, And Classification Using Lidar And Vision-Based Sensor Fusion, David John Thompson

Doctoral Dissertations and Master's Theses

Autonomous Surface Vehicles have the capability of replacing dull, dirty, and dangerous jobs in the maritime field. However, few successful ASV systems exist today, as there is a need for greater sensing capabilities. Furthermore, a successful ASV system requires object detection and recognition capabilities to enable autonomous navigation and situational awareness. This thesis demonstrates an application of LiDAR sensors in maritime environments for object detection, classification, and camera sensor fusion. This is accomplished through the integration of a high-fidelity GPS/INS system, 3D LiDAR sensors, and a pair of cameras. After rotating LiDAR returns into a global reference frame, they are …


Mission Tasking, Path Planning, And System Integration For An Autonomous Surface Vessel, Timothy Zuercher Nov 2017

Mission Tasking, Path Planning, And System Integration For An Autonomous Surface Vessel, Timothy Zuercher

Doctoral Dissertations and Master's Theses

This thesis presents the design and development of a fully autonomous surface vessel for use as a research platform for the Office of Naval Research and as a competition entry to the International Maritime RobotX Challenge in 2014 and 2016. The author’s contributions to this include the development of safety systems, power distribution systems, communications software, tasking software, and planning algorithms. The results of these developments include a hardware based safety system, a modular power and health monitoring system, an easy to use autoconfiguring inter-process communications stack, a dynamic tasking engine, and a comparison of two solutions to planning with …


Design And Prototyping Of A Shape-Changing Rigid-Body Human Foot In Gait, Tanner N. Rolfe Nov 2017

Design And Prototyping Of A Shape-Changing Rigid-Body Human Foot In Gait, Tanner N. Rolfe

Honors Theses

Traditional ankle-foot prostheses often replicate the physiological change in shape of the foot during gait via compliant mechanisms. In comparison, rigid-body feet tend to be simplistic and largely incapable of accurately representing the geometry of the human foot. Multi-segment rigid-body devices offer certain advantages over compliant mechanisms which may be desirable in the design of ankle-foot devices, including the ability to withstand greater loading, the ability to achieve more drastic shape-change, and the ability to be synthesized from their kinematics, allowing for realistic functionality without prior accounting of the complex internal kinetics of the foot. This work focuses on applying …


Improving Electrochemical Devices Via Increased Charge Density And Ceramic Nanoparticles, George Padavick Nov 2017

Improving Electrochemical Devices Via Increased Charge Density And Ceramic Nanoparticles, George Padavick

Honors Theses

Challenges posed by climate change in conjunction with increasing global energy demand necessitate improved energy systems in both transportation and power delivery. These systems will require more advanced energy storage than current commercially available options. To enhance energy storage capabilities, supercapacitors were investigated to discover new mechanisms, materials, and fabrication techniques for developing electrochemical devices. In particular, methods for improving electrolyte performance were explored to enhance capacitance and conductivity. The results indicate that increasing charge density in the electrolyte via higher salt concentration or higher ionic charge of the solvated ions significantly increases capacitance. Specifically, a 0.1M solution of magnesium …


Design And Prototyping Of A Shape-Changing Rigid-Body Human Foot In Gait, Tanner N. Rolfe Nov 2017

Design And Prototyping Of A Shape-Changing Rigid-Body Human Foot In Gait, Tanner N. Rolfe

Honors Theses

Traditional ankle-foot prostheses often replicate the physiological change in shape of the foot during gait via compliant mechanisms. In comparison, rigid-body feet tend to be simplistic and largely incapable of accurately representing the geometry of the human foot. Multi-segment rigid-body devices offer certain advantages over compliant mechanisms which may be desirable in the design of ankle-foot devices, including the ability to withstand greater loading, the ability to achieve more drastic shape-change, and the ability to be synthesized from their kinematics, allowing for realistic functionality without prior accounting of the complex internal kinetics of the foot. This work focuses on applying …


Rapid Characterization Of Local Shape Memory Properties Through Indentation, Peizhen Li, Haluk E. Karaca, Yang-Tse Cheng Nov 2017

Rapid Characterization Of Local Shape Memory Properties Through Indentation, Peizhen Li, Haluk E. Karaca, Yang-Tse Cheng

Mechanical Engineering Faculty Publications

Shape memory alloys (SMAs) have the ability to show large recoverable shape changes upon temperature, stress or magnetic field cycling. Their shape memory, material and magnetic properties (e.g. transformation temperatures, strain, saturation magnetization and strength) determine their prospects for applications from small-scale microelectromechanical systems to large scale aerospace and biomedical systems. It should be noted that properties of SMAs are highly temperature dependent. Generally, the conventional mechanical characterization methods (e.g, tension, compression, and torsion) are used on bulk samples of SMAs to determine those properties. In this article, it will be shown that indentation technique can be used as an …