Engineering Commons^™

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 Re_τ ≈ 1000 (Re_θ ≈ 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 …

Virtual Commissioning For Industrial Automation, Saihiranmitra Mudiki

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Business and Technology at Morehead State University in partial fulfillment of the requirements for the Degree Master of Science by Saihiranmitra Mudiki on November 7, 2017.

Sic Fibers And Sic/Sic Ceramic Matrix Minicomposites Damage Behavior, Amjad Almansour

Ceramic Matrix Composites: Science and Technology of Materials, Design, Applications, Performance and Integration

Silicon Carbide based Ceramic Matrix Composites (CMCs) are attractive materials for use in high-temperature applications in the aerospace industry. The performance and durability of a CMC depends on the properties of its constituents. Therefore, the limitations and damage mechanisms of CMC matrix and fiber reinforcement are discussed and characterized in representative simulated application conditions, and the dominant damage mechanisms at elevated temperatures are identified. The tensile creep behavior of single Hi-Nicalon^TM Type S and Sylramic^TM SiC fibers was characterized via testing and creep parameters were extracted. Fiber creep tests were performed in air or vacuum at 1200-1482°C under …

Image Analysis, Synthesis And Image-Based Modeling Of Ceramic-Matrix Composites, Gerard L. Vignoles

Ceramic Matrix Composites: Science and Technology of Materials, Design, Applications, Performance and Integration

This presentation will summarize some current research performed at LCTS on CMCs imaging and image-based modeling. Several aspects of SiC fiber-reinforced non-oxide CMCs production and use are envisaged. First, processing by chemical vapor infiltration is addressed through a series of modeling tools allowing the prediction of infiltration gradients as a function of the processing parameters and of the fibrous architecture. Second, the self-healing capability of multiphase, boron- and silicon-containing matrices is modeled through the use of a specific image-based method. Third, the high-temperature mechanical behavior of these materials is investigated by a thorough analysis of time series of X-ray µ-CT …

The Control Of Water Contaminants Assisted By Natural Materials, Wen Zhao

USF Tampa Graduate Theses and Dissertations

Natural materials can be used to remove water contaminants by applying proper physical, chemical, and biological water treatment processes. This study involves using natural materials, as they are considered to be more environmentally benign and cost-effective than synthetic materials. This dissertation concentrates on monitoring five major water quality parameters—ammonia, fluoride, turbidity, pH, and fecal indicator bacteria (FIB) —in two major applications where clean water is needed. The focus is on meeting the water quality requirements for each contaminant. The overall objective of this study is to control the levels of ammonia in aquaculture wastewater, and adjust fluoride, turbidity, pH, and …

Transferable Multiparty Computation, Michael R. Clark, Kenneth M. Hopkinson

AFIT Patents

A method and apparatus are provided for secure multiparty computation. A set of first parties is selected from a plurality of first parties for computation. Inputs for computation associated with each party in the set of first parties are divided into shares to be sent to other parties in the set of first parties. The computation on the shares is performed by the set of first parties using multiparty computation functions. In response to a trigger event, shares of the set of first parties are transferred to a set of second parties selected from a plurality of second parties. The …

Macroscopic Anisotropic Bone Material Properties In Children With Severe Osteogenesis Imperfecta, Carolyne Albert, John Jameson, Sergey Tarima, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Children with severe osteogenesis imperfecta(OI) typically experience numerous fractures and progressive skeletal deformities over their lifetime. Recent studies proposed finite element models to assess fracture risk and guide clinicians in determining appropriate intervention in children with OI, but lack of appropriate material property inputs remains a challenge. This study aimed to characterize macroscopic anisotropic cortical bone material properties and investigate relationships with bone density measures in children with severe OI. Specimens were obtained from tibial or femoral shafts of nine children with severe OI and five controls. The specimens were cut into beams, characterized in bending, and imaged by synchrotron …

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 …

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 …

Numerical Evaluation Of The Lateral Behavior Of Vertical And Battered Pile Group Foundations Using 3-D Finite Element Modeling, Ahmad Souri

LSU Doctoral Dissertations

The design of pile foundations to resist lateral loads is essential in offshore structures and bridge foundations. The lateral behavior of piles has been studied in the past by experimental investigations coupled with analytical and numerical methods. The problem is complex due to the nonlinearities from soil behavior, gap formation, and pile-soil-pile interaction in pile groups (or the group effect). In this work, the finite element (FE) modeling was used to study the lateral behavior of pile groups. The FE method is robust and allows incorporating the necessary aspects for studying the behavior of pile groups. The nonlinear material behavior …

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 …

Comprehensive Evaluation Of Rutting Performance Of Asphalt Concrete Mixtures, Ivan Syed

Civil Engineering ETDs

Rutting is the permanent deformation along the wheel paths of an asphalt pavement caused by repeated traffic loading. It is considered as one of the primary distresses of asphalt pavements. Recently, Hamburg Wheel Tracking Device (HWTD) has shown to measure the rutting performance of an asphalt mixture in the laboratory. In this study, this device has been used to measure rutting of asphalt concrete (AC) and relate them with the mixture’s dynamic modulus. To this end, the rut deformation of AC mixtures were modeled in this study using a semi-empirical |E*|-based rut predictive model based on the HWTD …

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 .

High Temperature Magneto-Structural Transition In Van Der Waals-Layered -Mocl3, Michael Mcguire, Jiaqiang Yan, Paula Lampen-Kelley, Andrew May, Valentino Cooper, Lucas Lindsay, Alexander Puretzky, Liangbo Liang, Santosh Kc, Ercan Cakmak, Stuart Calder, Brian Sales

Faculty Publications

The crystallographic and magnetic properties of the cleavable 4d3 transition metal compound α−MoCl3 are reported, with a focus on the behavior above room temperature. Crystals were grown by chemical vapor transport and characterized using temperature dependent x-ray diffraction, Raman spectroscopy, and magnetization measurements. A structural phase transition occurs near 585 K, at which the Mo-Mo dimers present at room temperature are broken. A nearly regular honeycomb net of Mo is observed above the transition, and an optical phonon associated with the dimerization instability is identified in the Raman data and in first-principles calculations. The crystals are diamagnetic at room temperature …

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 …

Overview Of Ceramic Matrix Composite Research At Nasa Glenn Research Center, James D. Kiser Et Al, Joseph E. Grady, Craig E. Smith, Roy M. Sullivan, Valerie L. Wiesner, Janet B. Hurst, Steven M. Arnold, Dongming Zhu, Amjad S. Almansour, Ramakrishna T. Bhatt, Sreeramesh Kalluri, Sai Raj

Ceramic Matrix Composites: Science and Technology of Materials, Design, Applications, Performance and Integration

In support of NASA’s Aeronautics Research Mission, the Glenn Research Center in Cleveland, OH, has been developing and assessing the performance of high temperature SiC/SiC ceramic matrix composites (CMCs), both with and without protective coatings, for turbine engine applications. Combinations of highly creep-resistant SiC fibers, advanced 3D weaves, durable environmental barrier coatings (EBCs), and a 2700°F-capable hybrid SiC matrix have been evaluated. The effects of steam and thermal gradients on composite durability and means of monitoring and modeling damage are also being investigated. Additional studies focused on understanding the creep of SiC fibers and the behavior of SiC/SiC minicomposites that …

Updated Composite Materials Handbook-17 (Cmh-17) Volume 5 - Ceramic Matrix Composites, James Doug Kiser, Rachael Andrulonis, Cindy Ashforth, Kaia E. David, Curtis Davies

Ceramic Matrix Composites: Science and Technology of Materials, Design, Applications, Performance and Integration

A wide range of issues must be addressed during the process of certifying CMC (ceramic matrix composite) components for use in commercial aircraft. The Composite Materials Handbook-17, Volume 5, Revision A on ceramic matrix composites has just been revised to help support FAA certification of CMCs for elevated temperature applications. The handbook supports the development and use of CMCs through publishing and maintaining proven, reliable engineering information and standards that have been thoroughly reviewed. Volume 5 contains detailed sections describing CMC materials/processing, design/analysis guidelines, testing procedures, and data analysis and acceptance. A review of the content of this latest revision …

High Temperature Composite Overview In France, Marc Montaudon, Eric Bouillon

Ceramic Matrix Composites: Science and Technology of Materials, Design, Applications, Performance and Integration

Exactly 40 years after the first production of a high temperature composite material in France, this presentation recalls the history of the development of the related technologies and applications.

We will describe how, under the leadership of Société Européenne de Propulsion (SEP) until 1994 and since then of the SAFRAN Group, different families of composites were successively developed and brought to an industrial stage: carbon fibers reinforced carbon, carbon fibers reinforced ceramic, ceramic fibers reinforced ceramics, reaching in 2017 a total volume of production of more than 1,000 metric tons per year.

Please click Additional Files below to see the …

Learning To Predict Clinical Outcomes From Soft Tissue Sarcoma Mri, Hamidreza Farhidzadeh

USF Tampa Graduate Theses and Dissertations

Soft Tissue Sarcomas (STS) are among the most dangerous diseases, with a 50% mortality rate in the USA in 2016. Heterogeneous responses to the treatments of the same sub-type of STS as well as intra-tumor heterogeneity make the study of biopsies imprecise. Radiologists make efforts to find non-invasive approaches to gather useful and important information regarding characteristics and behaviors of STS tumors, such as aggressiveness and recurrence. Quantitative image analysis is an approach to integrate information extracted using data science, such as data mining and machine learning with biological an clinical data to assist radiologists in making the best recommendation …

Conflict Reduction Techniques For Gpu Transactional Memory Systems, Sui Chen

LSU Doctoral Dissertations

The continued evolution of GPUs have enabled the use of irregular algorithms which involve fine-grained data sharing between threads, as well as transaction processing applications such as databases. Transactional Memory (TM) is derived from databases, which by itself is a programming construct that simplifies the programming of parallel workloads and combines the advantages of traditional approaches including fine-grained and coarse-grained locking. While hardware support for TM has started to enter mainstream commodity products, it is much farther from becoming reality on the GPU and is still being researched. In this dissertation, we study the challenges for supporting transactional workloads on …

Modeling Of Thermally Aware Carbon Nanotube And Graphene Based Post Cmos Vlsi Interconnect, K M Mohsin

LSU Doctoral Dissertations

This work studies various emerging reduced dimensional materials for very large-scale integration (VLSI) interconnects. The prime motivation of this work is to find an alternative to the existing Cu-based interconnect for post-CMOS technology nodes with an emphasis on thermal stability. Starting from the material modeling, this work includes material characterization, exploration of electronic properties, vibrational properties and to analyze performance as a VLSI interconnect. Using state of the art density functional theories (DFT) one-dimensional and two-dimensional materials were designed for exploring their electronic structures, transport properties and their circuit behaviors. Primarily carbon nanotube (CNT), graphene and graphene/copper based interconnects were …

Load Planning Processes To Enhance Cargo Compartment Utilization, Nathan J. Carlson, Adam D. Reiman, Robert E. Overstreet, Matthew A. Douglas

Faculty Publications

Purpose: The United States Air Force often provides effective airlift for cargo distribution, but is at times inefficient. This paper aims to address the under-utilization of military airlift cargo compartments that plagues the airlift system.
Design/methodology/approach: The authors examine seven techniques designed to increase cargo compartment utilization and increase airlift utilization rates. The techniques were applied through load planning software to 30 real-world movements consisting of 159 sorties. They then ran each post-technique movement through a modeled flight environment to obtain cycle movement data. The metrics gained from both the load planning software and the modeled environment were regressed to …

Conference Program, Yutaka Kagawa, Dongming Zhu, Ram Darolia, Rishi Raj

Ceramic Matrix Composites: Science and Technology of Materials, Design, Applications, Performance and Integration

No abstract provided.

The Potential Of Plasma Activation For Eb-Pvd Of Ebc Systems On Cmc Components, Burkhard Zimmermann, Gösta Mattausch, Bert Scheffel, Jens-Peter Heinß, Frank-Holm Rögner, Christoph Metzner

Ceramic Matrix Composites: Science and Technology of Materials, Design, Applications, Performance and Integration

Gas turbines are subject of intense research and development in order to meet increasing demands on fuel efficiency, reduction of emissions, or enhanced power. One of the major keys is improving the thermal efficiency by increased gas temperature within the turbine. In the hot turbine section, nickel-based superalloy components with thermal barrier coatings are utilized, which are still being refined and improved. Nevertheless, in order to significantly increase temperature capability and turbine efficiency, silicon-based non-oxide ceramics are being investigated and introduced as new base materials, allowing for lower-weight components operating at elevated temperatures. Severe weight losses due to water vapor …

2015 - Salinas River Watershed Area Salt Modeling Assessment Prepared For California Central Coast Regional Water Quality Control Board And The U.S. Environmental Protection Agency, Region Ix

Miscellaneous Monterey and San Luis Obispo County Documents and Reports

A November 2015 report prepared by Tetra Tech for California Central Coast Regional Water Quality Control Board and the U.S. Environmental Protection Agency, Region IX. The purpose was for the informed development of salt-related TMDLs by the CCRWQCB and a salt and nutrient management plan for the Salinas Valley aquifers. Three reaches reported 2010 303(d) listings for salt-related impairments in these watersheds including impairments due to chloride, sodium, electrical conductivity, and total dissolved solids – Lower Salinas River, Santa Rita Creek, and Alisal Creek. This report provides data analysis and a literature review (Sections 1 through 5), development of a …

Green Synthesis Of Copper Oxide Nanoparticles In Aqueous Medium As A Potential Efficient Catalyst For Catalysis Applications, Hany A. Elazab Dr

Chemical Engineering

In this research, we have developed a reliable green method for the synthesis of copper oxide nanoparticles as a potential efficient catalyst for several catalysis applications. In our experimental approach, microwave-assisted synthesis technique was used in order to perform chemical reduction of copper salt using hydrazine hydrate as a strong reducing agent. The prepared catalyst was characterized using various techniques showing the formation of well dispersed copper oxide nanoparticles. The synthesized Copper oxide catalyst shows many advantages including the use of environmentally benign solvent systems,

Performance Results Of Using Waste Vegetable Oil Based Biodiesel Fuel In A Turboshaft Gas Turbine Engine, Donald Bartlett 5218591, Blaine M. Heisner

ASA Multidisciplinary Research Symposium

The purpose of this research is to record and compare the operating parameters of a turboshaft gas turbine engine using two different blends of biodiesel fuel and the standard Jet A fuel.

What Happens To Nox Emissions Of Vw Diesel Cars When Water/Methanol Injection Is Used?, Andrew Croxell

ASA Multidisciplinary Research Symposium

Volkswagen has come under fire for their "Clean Diesel" automobiles that were found to emit too much NOx (Oxides of Nitrogen) when driven on the street. Since NOx is created by high temperature combustion events, the addition of a water/methanol injection system was tested on a VW diesel vehicle to identify if it could cool combustion temperatures and thus reduce NOx to an acceptable specification.

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.

Progress Towards An Opposed Piston Two Stroke Gasoline Aviation Engine, Donald R. Morris

ASA Multidisciplinary Research Symposium

Opposed Piston Engine Technology is not new, but its application to small two-stroke gasoline engines is unexplored. This presentation explores the potential advantages of such an engine as well as progress towards a workable design.