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Structural Analysis and Finite Element Modeling of Aluminum Honeycomb Sandwich Structures

Description: The objective of this research is to determine how the sandwich's physical characteristics have an impact on the mechanical properties, determine under what conditions the specimens will be lighter and mechanically stronger, and determine if the use of an aluminum honeycomb sandwich as a construction material is feasible. The research has aimed at the use of aluminum sandwiches as light and strong material. The study of the structural layers' damage resistance and tolerance demonstrated that th… more
Date: May 2021
Creator: Doukoure, Maimouna
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Seismic Performance Evaluation of Novel Cold-Formed Steel Framed Shear Walls Sheathed with Corrugated Steel Sheets

Description: This thesis presents experiments and numerical analysis of a novel cold-formed steel framed shear wall sheathed with corrugated steel sheets. The objective of this newly designed shear wall is to meet the growing demand of mid-rise buildings and the combustibility requirement in the International Building Code. The strength of the novel shear wall is higher than currently code certified shear wall in AISI S400-15 so that it could be more favorable for mid-rise building in areas that are prone t… more
Date: August 2017
Creator: Lan, Xing
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Using Motor Electrical Signature Analysis to Determine the Mechanical Condition of Vane-Axial Fans

Description: The purpose of this research was a proof of concept using a fan motor stator as transducer to monitor motor rotor and attached axial fan for mechanical motion. The proof was to determine whether bearing faults and fan imbalances could be detected in vane-axial fans using Motor Electrical Signature Analysis (MESA). The data was statistically analyzed to determine if the MESA systems could distinguish between baseline conditions and discrete fault frequencies for the three test conditions: beari… more
Date: August 2002
Creator: Doan, Donald Scott
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Topology and Lattice-Based Structural Design Optimization for Additively Manufactured Medical Implants

Description: Topology-based optimization techniques and lattice structures are powerful ways to accomplish lightweight components with enhanced mechanical performance. Recent developments in additive manufacturing (AM) have led the way to extraordinary opportunities in realizing complex designs that are derived from topology and lattice-based structural optimization. The main aim of this work is to give a contribution, in the integration between structural optimization techniques and AM, by proposing a setu… more
Date: May 2019
Creator: Peto, Marinela
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Computer Virus Spread Containment Using Feedback Control.

Description: In this research, a security architecture based on the feedback control theory has been proposed. The first loop has been designed, developed and tested. The architecture proposes a feedback model with many controllers located at different stages of network. The controller at each stage gives feedback to the one at higher level and a decision about network security is taken. The first loop implemented in this thesis detects one important anomaly of virus attack, rate of outgoing connection. Tho… more
Date: December 2004
Creator: Yelimeli Guruprasad, Arun
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Determination of the Shelf Life of Aluminum Electrolytic Capacitors.

Description: The aluminum electrolytic capacitor is used extensively in the electric utility industry. A factor limiting the storage of spare capacitors is the integrity of the aluminum oxide dielectric, which over time breaks down contributing to a shelf life currently estimated at one nuclear power electric generating station to be approximately five years. This project examined the electrical characteristics of naturally aged capacitors of several different styles to determine if design parameters were… more
Date: May 2002
Creator: Wynne, Edward McFaddin
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Radio frequency propagation differences through various transmissive materials.

Description: The purpose of this research was to determine which of the commonly used wireless telecommunication site concealment materials has the least effect on signal potency. The tested materials were Tuff Span® fiberglass panels manufactured by Enduro Composite Systems, Lexan® XL-1 polycarbonate plastic manufactured by GE Corporation and Styrofoam™ polystyrene board manufactured by The Dow Chemical Company. Testing was conducted in a double electrically isolated copper mesh screen room at the Univer… more
Date: December 2002
Creator: Ryan, Patrick L.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Characterization of Iron Oxide Deposits Formed at Comanche Peak Steam Electric Station

Description: The presence of deposits leading to corrosion of the steam generator (SG) systems is a major contributor to operation and maintenance cost of pressurized water reactor (PWR) plants. Formation and transport of corrosion products formed due to the presence of impurities, metallic oxides and cations in the secondary side of the SG units result in formation of deposits. This research deals with the characterization of deposit samples collected from the two SG units (unit 1 and unit 2) at Comanche P… more
Access: Restricted to the UNT Community Members at a UNT Libraries Location.
Date: May 2003
Creator: Namduri, Haritha
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

A Computer-Based Process Control System for a Target Station in a LINAC Facility

Description: An event-driven, sequential, process control system was designed for International Isotopes, Inc., to automate and remotely control a target station at the company's linear accelerator facility. The designed system consisted of two major sections: a software program (virtual instrument), which was developed by LabVIEW, and a hardware interface (FieldPoint Modular Distributed I/O System by National Instrument), which had to be a pre-developed system that did not require customization. The design… more
Date: May 1999
Creator: Al-Shantaf, Abdulraouf O.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Design of a Monitoring System for a Plasma Cleaning Machine

Description: Plasma cleaning is the most effective dry process to remove surface contaminates from a SAW (Surface Acoustical Wave) device. Consistent gas pressures, flows, and good electrical connections between the chamber shelves are necessary for the process to function predictably. In addition, operation of the monitoring system must be transparent to the plasma cleaning unit. This thesis describes a simple solution to the complex problem of monitoring a plasma cleaning system. The monitoring system use… more
Date: May 1999
Creator: Fooks, Terry M. (Terry Max)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

A Data Acquisition System Experiment for Gas Temperature and Pressure Measurements on a Liquid-Nitrogen-Powered Vehicle

Description: A data acquisition system was set up to measure gas temperatures and pressures at various points on a liquid-nitrogen-powered vehicle. The experiment was attempted to develop a data acquisition method for applications on engines that use liquid air as the fuel. Two thermocouples and a pressure transducer were connected using data acquisition instruments interfaced to a laptop computer to acquire data.
Date: May 1998
Creator: Lui, Samson Sze-Sang
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Effects of Thickness and Indenter Tip Geometry in Nanoindentation of Nickel Films

Description: Nanoindentation has become a widely used technique to measure the mechanical properties of materials. Due to its capability to deform materials in micro- and nano-scale, nanoindentation has found more applications in characterizing the deformation behavior and determining the mechanical properties of thin films and coatings. This research deals with the characterization of samples received from Center for Advanced Microstructures and Devices (CAMD) and Integran Technologies Inc., Toronto, Canad… more
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Date: May 2004
Creator: Parakala, Padma
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Effects of a Surface Engineered Metallic Coating on Elastomeric Valve Stem Seal Leakage

Description: Valve stem seal leakage is a major source of fugitive emissions, and controlling these emissions can result in added expense in leak detection and repair programs. Elastomeric O-rings can be used as valve stem seals, and O-ring manufacturers recommend lubrication of elastomeric seals to prevent damage and to assure proper sealing. In this research, a metallic coating was applied as a lubricant using a vacuum vapor deposition process to the surface of elastomeric valve stem seals. Valve stem le… more
Date: December 2000
Creator: Taylor, John Abner
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

FEM of nanoindentation on micro- and nanocrystalline Ni: Analysis of factors affecting hardness and modulus values.

Description: Nanoindentation is a widely used technique to measure the mechanical properties of films with thickness ranging from nanometers to micrometers. A much better understanding of the contact mechanics is obtained mostly through finite element modeling. The experiments were modeled using the software package Nano SP1 that is based on COSMOSM™ (Structural Research & Analysis Corp, www.cosmosm.com), a finite element code. The fundamental material properties affecting pile-up are the ratio of the effec… more
Date: August 2005
Creator: Pothapragada, Raja Mahesh
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

FPGA Prototyping of a Watermarking Algorithm for MPEG-4

Description: In the immediate future, multimedia product distribution through the Internet will become main stream. However, it can also have the side effect of unauthorized duplication and distribution of multimedia products. That effect could be a critical challenge to the legal ownership of copyright and intellectual property. Many schemes have been proposed to address these issues; one is digital watermarking which is appropriate for image and video copyright protection. Videos distributed via the Inter… more
Date: May 2007
Creator: Cai, Wei
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Fabrication and Testing of Biomimetic Microstructures for Walkway Tribometers

Description: The main objective of this work is to give contribution in both additive manufacturing (AM) and tribometry derived from the application and study of materials available with the use of biomimetic designs. Additional contributions are determining what effects treatments for flooring surfaces may have on the dynamic coefficient of friction and the effects of these products on common surfaces. The validity of the proposed methodology for a proof of concept was demonstrated by comparing measured dy… more
Date: December 2019
Creator: Haney, Christopher Willard
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Linearity and monotonicity of a 10-bit, 125 MHz, segmented current steering digital to analog converter

Description: The purpose of this research is to determine the linearity and monotonicity of the THS5651IDW digital to analog converter (DAC), a prototype of the future Texas Instruments TLV5651, 10-bit, 125 MHz communication DAC. Testing was conducted at the Texas Instruments facility on Forest Lane, Dallas, Texas. Texas Instruments provided test equipment, software and laboratory space to obtain test data. Analysis of the data found the DAC to be monotonic since the magnitude of the differential nonlineari… more
Date: May 2000
Creator: Bittle, Charles C.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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