Engineering Science and Materials Commons^™

Variable Block Size Motion Compensation In The Redundant Wavelet Domain, Ahmed Abdelgadir Suliman

Dissertations

Video is one of the most powerful forms of multimedia because of the extensive information it delivers. Video sequences are highly correlated both temporally and spatially, a fact which makes the compression of video possible. Modern video systems employ motion estimation and motion compensation (ME/MC) to de-correlate a video sequence temporally. ME/MC forms a prediction of the current frame using the frames which have been already encoded. Consequently, one needs to transmit the corresponding residual image instead of the original frame, as well as a set of motion vectors which describe the scene motion as observed at the encoder. The …

The Influence Of Pressure Relaxation On The Structure Of An Axial Vortex, Robert L. Ash, Irfan Zardadkhan, Allan J. Zuckerwar

Mechanical & Aerospace Engineering Faculty Publications

Governing equations including the effects of pressure relaxation have been utilized to study an incompressible, steady-state viscous axial vortex with specified far-field circulation. When sound generation is attributed to a velocity gradient tensor-pressure gradient product, the modified conservation of momentum equations that result yield an exact solution for a steady, incompressible axial vortex. The vortex velocity profile has been shown to closely approximate experimental vortex measurements in air and water over a wide range of circulation-based Reynolds numbers. The influence of temperature and humidity on the pressure relaxation coefficient in air has been examined using theoretical and empirical approaches, and …

Calibration Of Alumina-Epoxy Nanocomposites Using Piezospectroscopy For The Development Of Stress-Sensing Adhesives, Amanda L. Stevenson

Electronic Theses and Dissertations

A non-invasive method to quantify the stress distribution in polymer-based materials is presented through the piezospectroscopic calibration of alumina-epoxy nanocomposites. Three different alumina volume fraction nanocomposites were created and loaded under uniaxial compression in order to determine the relationship between applied stress and the frequency shift of the R-lines produced by alumina under excitation. Quantitative values for six piezospectroscopic coefficients were obtained which represent the stress-sensing property of the nanocomposites. The results were applied to an alumina-filled adhesive in a single lap shear configuration demonstrating the capability of the technique to monitor R-line peak positions with high spatial resolution and …

New Media Icc Profiles Construction And Concerns, Reem El Asaleh

Dissertations

With the advent of the modern digital technology, users can now capture an image and reproduce it between different media, such as display it on LCD monitor or tablet computer, print it on desktop printer or send it to a printing press. The challenge has been then to maintain the accuracy of image colors during this reproduction, which has led to the development of Color Management Systems. Using these systems, the color reproduction across-media will be accomplished using device ICC profiles that describe each device’s color characterization data in a standardized format based on International Color Consortium (ICC) specifications.

ICC …

Performance Of Control Room Operators In Alarm Management, Dileep Buddaraju

LSU Master's Theses

Pipelines transport millions of barrels of petroleum products every day. These systems have significant safety concerns. The BP oil spill in the Gulf of Mexico, while concerned with oil and gas extraction rather than distribution, shares many of the same safety and reliability issues as distribution systems, and demonstrates the significant potential for major disasters in the pipeline industry. In this work, a research study is being conducted to further understanding of the role of operators in the management of alarm systems and to measure the performance of operators in handling abnormal situations like pressure loss, liquid inflow/outflow variation and …

Solving Evolution Equations For Triad Interaction Of Shallow Water Waves, Qian Zhang

LSU Master's Theses

This study focuses on solving the evolution equations for triad interaction in shallow water waves. First, the evolution equations based on Boussinesq-type equations with Pad¨¦ approximant of the exact linear phase velocity using multi-scale perturbation analysis are derived. Next, methods of solving the complex equation directly, splitting the complex function into amplitude and phase functions, and splitting complex function into real and imaginary parts are implemented to solve the evolution equations. Then the fourth-order Runge-Kutta (RK4) numerical scheme is employed to solve the evolution equations, and corresponding numerical results of three wave interaction are presented demonstrating the sensitivity of the …

The Transient Wave Effect And Real Losses Correlation-Frequency, Temporal, And Spatial Analysis, Dina Sa Knight

LSU Master's Theses

Water distribution systems are prone to transients since pumps need to be started and stopped, pumps may have sudden flow changes, human blunders can occur, equipment may fail, or other unavoidable natural events may ensue. Surge modeling techniques are available to calculate variations in pressure, under extreme or normal operating conditions, serving as a tool to predict extreme events in order to design a suitable system and, or, to aid in the implementation of proper measures to mitigate transients. However, modeling an entire water network system may not be cost effective and may require extensive research and time especially in …

Comparison Of Different Integral Histogram Based Tracking Algorithms, Sriharsha Atluri

LSU Master's Theses

Object tracking is an important subject in computer vision with a wide range of applications – security and surveillance, motion-based recognition, driver assistance systems, and human-computer interaction. The proliferation of high-powered computers, the availability of high quality and inexpensive video cameras, and the increasing need for automated video analysis have generated a great deal of interest in object tracking algorithms. Tracking is usually performed in the context of high-level applications that require the location and/or shape of the object in every frame. Research is being conducted in the development of object tracking algorithms over decades and a number of approaches …

An Euler Solver For Nonlinear Water Waves Using A Modified Staggered Grid And Gaussian Quadrature Approach, Qi Fan

LSU Master's Theses

A structured, finite-volume Euler solver for non-hydrostatic, free surface flows is developed to simulate coastal nonlinear dispersive water waves. A semi-implicit projection method which splits the pressure term into hydrostatic and non-hydrostatic parts is employed. A vertically shifted, staggered grid is designed to accommodate a new Gaussian discharge calculator and to facilitate the enforcement of a non-hydrostatic free-surface boundary condition. The Gaussian discharge calculator on the shifted grid increases the dispersion accuracy compared to traditional approaches that calculate discharges on a regular staggered grid. Numerical results are presented to demonstrate the improvements of these methods.

Effects Of Silicon Content And Cooling Rate On Mechanical Properties Of Heavy Section Ductile Cast Iron , Meghan Haycock

Dissertations, Master's Theses and Master's Reports - Open

The effects of Si and cooling rate are investigated for their effect on the mechanical properties and microstructure. Three alloys were chosen with varying C and Si contents and an attempt to keep the remainder of the elements present constant. Within each heat, three test blocks were poured. Two blocks had chills – one with a fluid flowing through it to cool it (active chill) and one without the fluid (passive) – and the third block did not have a chill. Cooling curves were gathered and analyzed. The mechanical properties of the castings were correlated to the microstructure, cooling rate …

Processing And Mechanical Properties Of Cast Aluminum Containing Scandium, Zirconium, And Ytterbium , Nicholas D. Johnson

Dissertations, Master's Theses and Master's Reports - Open

A series of aluminum alloys containing additions of scandium, zirconium, and ytterbium were cast to evaluate the effect of partial ytterbium substitution for scandium on tensile behavior. Due to the high price of scandium, a crucible-melt interaction study was performed to ensure no scandium was lost in graphite, alumina, magnesia, or zirconia crucibles after holding a liquid Al-Sc master alloy for 8 hours at 900 °C in an argon atmosphere. The alloys were subjected to an isochronal aging treatment and tested for conductivity and Vickers microhardness after each increment. For scandium-containing alloys, peak hardnesses of 520-790 MPa, and peak tensile …

High Temperature, Low Cycle Fatigue Of A Hybrid Particulate/Fiber Aluminum Metal-Matrix Composite , Justin Clark

Dissertations, Master's Theses and Master's Reports - Open

The effect of shot particles on the high temperature, low cycle fatigue of a hybrid fiber/particulate metal-matrix composite (MMC) was studied. Two hybrid composites with the general composition A356/35%SiC particle/5%Fiber (one without shot) were tested. It was found that shot particles acting as stress concentrators had little effect on the fatigue performance. It appears that fibers with a high silica content were more likely to debond from the matrix. Final failure of the composite was found to occur preferentially in the matrix. SiC particles fracture progressively during fatigue testing, leading to higher stress in the matrix, and final failure by …

Effects Of Thermo-Mechanical Loading From In-Situ Studies Of Eb-Pvd Thermal Barrier Coatings, Melan N. Jansz

Electronic Theses and Dissertations

The thermo-mechanical effects on the strain evolution within an EB-PVD thermal barrier coating (TBC) is presented in this work using in-situ characterization. Synchrotron X-ray diffraction at sector 1-ID at the Argonne National Laboratory provided both qualitative and quantitative in-situ data on the strain evolution under a thermal cycle with mechanical loading. The results show that at a critical combination of temperature and load, the stress in the thermally grown oxide (TGO) layer in the TBC reaches a tensile region. These significant findings enhance existing literature showing purely compressive strains within the TGO where mechanical loads have been neglected. The results …

Graphene Based Anode Materials For Lithium-Ion Batteries, Sree Lakshmi Cheekati

Browse all Theses and Dissertations

Improvements of the anode performances in Li-ions batteries are in demand to satisfy applications in transportation. In comparison with graphitic carbons, transition metal oxides as well as graphene can store over twice amount of lithium per gram. Recently, graphene-based anodes for Li-ion batteries are under extensive development. In this research, lithium storage characteristics in graphene oxide (GO), GO/Manganese acetate (GO/MnAc), GO/manganese oxide (GO/MnOx) composites and Nano Graphene Platelets (NGP) were studied. The prepared GO delivered reversible capacities of 706mAh/g with an average columbic efficiency of 87%. Reversible capacities of 533 mAh/g were observed for GO/MnAc composite. GO/MnOx nanocomposite thermal annealed …

Highly Active Porous Catalysts Fabricated By Attachment Of Palladium Nanoparticles On Hierarchical Carbon Structures, Hema Vijwani

Browse all Theses and Dissertations

The effectiveness of metal-based catalysts can be significantly enhanced by increasing the available surface area relative to the volume through the creation of hierarchical nanostructures. The catalyst demonstrated here is palladium, which is a widely recognized heterogeneous catalyst suitable for a variety of industrial applications such as water purification, hydrogen storage, and electrochemical devices. In this study, a novel multi-scale supporting material developed in this group, has been used as support. It consists of micro-porous graphitic carbon with strongly attached carbon nanotubes. This can increase the surface area by orders of magnitude without increasing the size or weight while still …

The Functionalization And Characterization Of Adherent Carbon Nanotubes With Silver Nanoparticles For Biological Applications, Adam A. Maleszewski

Browse all Theses and Dissertations

The purpose of this project is to form silver nanoparticles (Ag-NP) attached to a hierarchical substrate for possible use in biological applications. The effectiveness of these Ag-NP-containing devices, including biofilters and biosensors, may be dramatically enhanced by the use of hierarchical structures such as carbon nanotubes (CNT), as they offer a high surface area surface suitable for cell-device interactions, while Ag-NP would be a suitable component in many such devices due to its plasmonic surface properties (e.g. in sensor and directed energy applications) and its anti-microbial properties (desirable for fluid filtration due to its low weight. Meaningful control over the …

Achieving High Efficiency Laminated Polymer Solar Cell With Interfacial Modified Metallic Electrode And Pressure Induced Crystallization, Yongbo Yuan, Yu Bi, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

We report efficient laminated organic photovoltaic device with efficiency approach the optimized device by regular method based on Poly(3-hexylthiophene-2,5-diyl) and [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM). The high efficiency is mainly attributed to the formation of a concrete polymer/metal interface mechanically and electrically by the use of electronic-glue, and using the highly conductive and flexible silver film as anode to reduce photovoltage loss and modifying its work function for efficiency hole extraction by ultraviolet/ozone treatment, and the pressure induced crystallization of PCBM.

In Vitro Models For Glaucoma Research: Effects Of Hydrostatic Pressure, Yuan Lei, Shadi Rajabi, Ryan M. Pedrigi, Darryl R. Overby, A. Thomas Read, C. Ross Ethier

Department of Mechanical and Materials Engineering: Faculty Publications

PURPOSE. The response of cells (e.g., optic nerve head [ONH] cells) to mechanical stress is important in glaucoma. Studies have reported the biological effects of hydrostatic pressure on ONH cells cultured on a rigid substrate. An apparatus, designed to independently vary hydrostatic pressure and gas tension (including oxygen tension) in culture medium, was used to evaluate the effects of pressure and tension on cell migration, shape, and α-tubulin architecture in a transformed cell line (DITNC1 rat cortical astrocytes).

METHODS. During the assay period, cells were exposed to one of four experimental configurations: (1) control pressure and control gas tension; (2) …

Impact Of Elliptical Trainer Ergonomic Modifications On Perceptions Of Safety, Comfort, Workout, And Usability For People With Physical Disabilities And Chronic Conditions, Judith M. Burnfield, Yu Shu, Thad W. Buster, Adam P. Taylor, Carl A. Nelson

Department of Mechanical and Materials Engineering: Faculty Publications

Background The popularity of elliptical training has grown in rehabilitation, fitness, and home settings as a means for improving fitness and walking, yet many people with physical disabilities and chronic conditions experience difficulties when trying to use elliptical trainers.

Objective The purpose of this study was to compare, for people with disabilities and chronic conditions, perceptions of safety, comfort, workout, and usability of 4 elliptical trainers before and after the development of a set of low-cost adaptations.

Design This study was a quasi-experimental repeated-measures investigation.

Methods Twenty adults with diverse medical conditions and functional abilities evaluated 4 elliptical trainers for …

Use Of Environmental Scanning Electron Microscopy For In Situ Observation Of Interaction Of Cells With Micro- And Nanoprobes, Alexander Goponenko, B. J. Boyle, K. I. Jahan, Maxim V. Gerashchenko, Dmitri E. Fomenko, Vadim N. Gladyshev, Yuris A. Dzenis

Department of Mechanical and Materials Engineering: Faculty Publications

Precision intracellular sensing, probing and manipulation offer unprecedented opportunities for advances in biological sciences. Next-generation ultra-fine probes will be capable of targeting individual cell organelles. Development of such probes as well as probes capable of penetrating through tough cell walls requires detailed knowledge of cell-probe interaction. This Letter evaluated the applicability of environmental scanning electron microscopy (ESEM) for cell and cell-probe interaction imaging. Several types of cells (plant and yeast cells as well as mouse spermatozoa) were successfully imaged in their natural state, with mouse spermatozoa observed by ESEM for the first time. Computerized stage applied to image was tough …