Current Search: Structural analysis (x)
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- Title
- In-plane and out-of-plane components of structural intensity in thick structures.
- Creator
- Grandclement, Cyrille Nicolas., Florida Atlantic University, Cuschieri, Joseph M.
- Abstract/Description
-
In thick structures, vibrational power can propagate by both in-plane and out-of-plane waves. In performing measurements of power flow or structural intensity, it would be required that the components associated with the in-plane or out-of-plane waves be identified. Using a frequency wavenumber approach, the measured structural intensity can be decomposed into its different wave components. In this thesis, simulated structural intensity measurements are presented to demonstrate the use of...
Show moreIn thick structures, vibrational power can propagate by both in-plane and out-of-plane waves. In performing measurements of power flow or structural intensity, it would be required that the components associated with the in-plane or out-of-plane waves be identified. Using a frequency wavenumber approach, the measured structural intensity can be decomposed into its different wave components. In this thesis, simulated structural intensity measurements are presented to demonstrate the use of this frequency wavenumber technique. The results obtained show the distribution of the structural intensity into the wave components. The implementation of this technique using a laser based instrument is discussed. The required characteristics of the instrument, the number of channels, the spacing between the channels, and the phase accuracy, are described. Also, a table to perform the scanning for the frequency wavenumber analysis is presented.
Show less - Date Issued
- 1991
- PURL
- http://purl.flvc.org/fcla/dt/14707
- Subject Headings
- Structural dynamics, Structural analysis (Engineering)
- Format
- Document (PDF)
- Title
- STRUCTURALISM'S CRITIQUE OF THE ROMANTIC MYTH OF THE AUTHOR.
- Creator
- MONTALBANO, MARGARET., Florida Atlantic University, Pearce, Howard D.
- Abstract/Description
-
Structuralism's Critique of the Romantic Myth of the Author is aimed at the Romantic concept of the author as a special individual possessed of unique sensibilities and God-like powers of creation. The structuralist analysis of this myth is an attempt to decompose - to separate into its component parts - the Romantic image of the author. This act of decomposition enables structuralism to demonstrate the construction of this myth and to suggest its implausability from a perspective informed by...
Show moreStructuralism's Critique of the Romantic Myth of the Author is aimed at the Romantic concept of the author as a special individual possessed of unique sensibilities and God-like powers of creation. The structuralist analysis of this myth is an attempt to decompose - to separate into its component parts - the Romantic image of the author. This act of decomposition enables structuralism to demonstrate the construction of this myth and to suggest its implausability from a perspective informed by structuralist theory. In the course of this analysis, structuralism is able to suggest some of the functions of the myth within literature as well as within contemporary Western culture.
Show less - Date Issued
- 1983
- PURL
- http://purl.flvc.org/fcla/dt/14176
- Subject Headings
- Structuralism (Literary analysis), Authorship, Romanticism
- Format
- Document (PDF)
- Title
- Identification of support conditions on a beam using finite element analysis.
- Creator
- Ramakrishna, Suresh Babu., Florida Atlantic University, Stevens, Karl K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The equivalent end deflections and rotations for beams with integral, but dissimilar, elastic supports were determined. Finite element analysis was used to generate the midsurface deflection of the beam. Numerical results were then fit to the analytical solution for the deflection of a beam, yielding the equivalent end slope resulting from deformations in the support. The lateral deflection at the support was available directly from the finite element calculation. The approach used for...
Show moreThe equivalent end deflections and rotations for beams with integral, but dissimilar, elastic supports were determined. Finite element analysis was used to generate the midsurface deflection of the beam. Numerical results were then fit to the analytical solution for the deflection of a beam, yielding the equivalent end slope resulting from deformations in the support. The lateral deflection at the support was available directly from the finite element calculation. The approach used for modeling of the supports is discussed. It was found that the slope and deflection at the support increase as the relative stiffness of the support decreases, as would be expected. Results are presented for both cantilever and beams with fixed ends, are valid for slender beams with small deflection.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/15021
- Subject Headings
- Girders, Finite element method, Elastic analysis (Engineering), Structural analysis (Engineering)
- Format
- Document (PDF)
- Title
- Carbon fiber/vinylester composites in the marine environment: EIS as a means of determining an effective composite interface.
- Creator
- Vinci, Chris J., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In this research, the degradation of carbon fiber/vinylester composites in marine environments was experimentally investigated. Additionally, two types of carbon fiber surface treatments, namely Polyhedral Oligomeric Silsesquioxane (POSS) and the industrial surface treatment F0E, were evaluated to determine their effectiveness in creating a fiber/matrix (F/M) interface for use in the marine environment. Electrochemical Impedance Spectroscopy (EIS) was explored as a new application of an...
Show moreIn this research, the degradation of carbon fiber/vinylester composites in marine environments was experimentally investigated. Additionally, two types of carbon fiber surface treatments, namely Polyhedral Oligomeric Silsesquioxane (POSS) and the industrial surface treatment F0E, were evaluated to determine their effectiveness in creating a fiber/matrix (F/M) interface for use in the marine environment. Electrochemical Impedance Spectroscopy (EIS) was explored as a new application of an existing technique for use in measuring the amount of water at the F/M interface in carbon fiber/vinylester composites. EIS spectra were used to determine equivalent electric circuit models that allow for the prediction of water at the interface. The location of water within the composite was determined through Positron Annihilation Lifetime Spectroscopy (PALS). Interlaminar shear strength and transverse tensile tests were carried out for dry conditions and after hygrothermal exposure of the composites to study the influence of the integrity of the F/M interface on the macroscopic response of the composite.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1930500
- Subject Headings
- Composite materials, Mechanical properties, Graphite fibers, Fibrous composites, Structural analysis
- Format
- Document (PDF)
- Title
- Dynamic response of plate structures to external excitations.
- Creator
- Mani, George., Florida Atlantic University, Yong, Yan, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The dynamic response of plate structures composed of rigidly connected thin plates subjected to point loads is studied. The finite strip method combined with a new approach for analyzing periodic structures is utilized to obtain substantial reduction in computational efforts. Each strip with various boundary conditions is treated as a waveguide capable of transmitting different wave motions. Wave scattering matrices are defined to characterize wave motions at boundaries, intersection of...
Show moreThe dynamic response of plate structures composed of rigidly connected thin plates subjected to point loads is studied. The finite strip method combined with a new approach for analyzing periodic structures is utilized to obtain substantial reduction in computational efforts. Each strip with various boundary conditions is treated as a waveguide capable of transmitting different wave motions. Wave scattering matrices are defined to characterize wave motions at boundaries, intersection of plates and where type of wave guides are changed. The results obtained from the application of the approach on various plate configurations are presented and discussed.
Show less - Date Issued
- 1990
- PURL
- http://purl.flvc.org/fcla/dt/14661
- Subject Headings
- Plates (Engineering)--Vibration, Finite strip method, Structural analysis (Engineering)
- Format
- Document (PDF)
- Title
- Compression failure of sandwich specimens with and without face/core debonds.
- Creator
- Vadakkeveedu, Vinod P., Florida Atlantic University, Carlsson, Leif A., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The objective of this thesis is to report on an experimental study on the compressive behavior of foam cored sandwich composite specimens with and without face/core debond. A test fixture was designed which enables a precisely machined sandwich specimen instrumented with back-to-back strain gages to be loaded in edgewise compression. Tests were conducted on specimens without implanted face/core interface debonds over a range of core densities and gage lengths. The experimentally determined...
Show moreThe objective of this thesis is to report on an experimental study on the compressive behavior of foam cored sandwich composite specimens with and without face/core debond. A test fixture was designed which enables a precisely machined sandwich specimen instrumented with back-to-back strain gages to be loaded in edgewise compression. Tests were conducted on specimens without implanted face/core interface debonds over a range of core densities and gage lengths. The experimentally determined compression strengths and failure modes were compared to closed-form predictions and finite element analysis. Specimens with an implanted through-the-width face/core debond were also tested and mechanism of failure was analyzed using finite element analysis. Good agreement between collapse loads predicted using geometrically nonlinear analysis and experimentally measured strengths was observed.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13047
- Subject Headings
- Sandwich construction, Strains and stresses, Structural analysis (Engineering)
- Format
- Document (PDF)
- Title
- Contextual Modulation of Competitive Object Candidates in Early Object Recognition.
- Creator
- Islam, Mohammed F., Barenholtz, Elan, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
Object recognition is imperfect; often incomplete processing or deprived information yield misperceptions (i.e., misidentification) of objects. While quickly rectified and typically benign, instances of such errors can produce dangerous consequences (e.g., police shootings). Through a series of experiments, this study examined the competitive process of multiple object interpretations (candidates) during the earlier stages of object recognition process using a lexical decision task paradigm....
Show moreObject recognition is imperfect; often incomplete processing or deprived information yield misperceptions (i.e., misidentification) of objects. While quickly rectified and typically benign, instances of such errors can produce dangerous consequences (e.g., police shootings). Through a series of experiments, this study examined the competitive process of multiple object interpretations (candidates) during the earlier stages of object recognition process using a lexical decision task paradigm. Participants encountered low-pass filtered objects that were previously demonstrated to evoke multiple responses: a highly frequented interpretation (“primary candidates”) and a lesser frequented interpretation (“secondary candidates”). When objects were presented without context, no facilitative effects were observed for primary candidates. However, secondary candidates demonstrated evidence for being actively suppressed.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004836, http://purl.flvc.org/fau/fd/FA00004836
- Subject Headings
- Pattern recognition systems., Information visualization., Artificial intelligence., Spatial analysis (Statistics), Latent structure analysis.
- Format
- Document (PDF)
- Title
- Durability of carbon fiber/vinylester composites subjected to marine environments and electrochemical interactions.
- Creator
- Hasnine, Md., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Degradation of the Carbon Fiber/Vinylester (CF/VE) polymer matrix composites due to different electrochemical interactions when exposed to seawater or at high temperature had been experimentally investigated. Water uptake behavior of composite specimen was examined based on weight gain measurement. Three point bending test was performed to quantify the mechanical degradation of composite immersed in seawater with different environmental and electrochemical interactions. Finally,...
Show moreDegradation of the Carbon Fiber/Vinylester (CF/VE) polymer matrix composites due to different electrochemical interactions when exposed to seawater or at high temperature had been experimentally investigated. Water uptake behavior of composite specimen was examined based on weight gain measurement. Three point bending test was performed to quantify the mechanical degradation of composite immersed in seawater with different environmental and electrochemical interactions. Finally, Electrochemical Impedance Spectroscopy (EIS) was used to better understanding of the degradation process in CF/VE composite produced by interactions between electrochemical and different environmental conditions. A detailed equivalent circuit analysis by using EIS spectra is also presented in an attempt to elucidate the degradation phenomenon in composites.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2683124
- Subject Headings
- Composite materials, Mechanical properties, Fibrous composites, Structural analysis, Polymeric composites, Spectrum analysis
- Format
- Document (PDF)
- Title
- Studies of composite multihull ship structures using fluid structure interaction.
- Creator
- Ma, Siyuan, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Studies of composite multihull structure under wave loads, extreme loads, and blast loads have been conducted using finite element and computational fluid dynamics (CPF) tools. A comprehensive finite element tool for structural analysis of composite multi-hull structures is developed. Two-way fluid structure interaction (FSI) is implemented by coupling finite element analysis (FEA) and CFD. FEA models have been developed using sandwich construction having composite face sheets and a foam core...
Show moreStudies of composite multihull structure under wave loads, extreme loads, and blast loads have been conducted using finite element and computational fluid dynamics (CPF) tools. A comprehensive finite element tool for structural analysis of composite multi-hull structures is developed. Two-way fluid structure interaction (FSI) is implemented by coupling finite element analysis (FEA) and CFD. FEA models have been developed using sandwich construction having composite face sheets and a foam core. Fluid domain was modeled using the CFD code, CFX and a wave motion was simulated based on Sea State 5... In addition to hydrodynamic loads, the simulation of composite ship under extreme loads is performed. Stress analysis was performed and dynamic response of the hull was determined in time domain. In the final analysis, an underwater explosion model was developed to study the composite hull resistance to blast load.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3355625
- Subject Headings
- Computational fluid dynamics, Numerical analysis, Engineering mathematics, Naval architecture, Structural analysis (Engineering)
- Format
- Document (PDF)
- Title
- Frequency Line Tracking in Spectrograms Using Hidden Markov Models.
- Creator
- Gunes, Tuncay, Erdol, Nurgun, Florida Atlantic University
- Abstract/Description
-
One of the limiting factors restricting aircraft landings at maJor airports is the minimum spacing requirements due to vortex wake avoidance. If it can be shown that the separation requirements are too conservative, then it may be possible to increase the rate of landings on a given runway. During August/September 2003, NASA and the (United States Department of Transportation) USDOT sponsored a wake acoustics test at the Denver International Airport. The central instrument of the test was a...
Show moreOne of the limiting factors restricting aircraft landings at maJor airports is the minimum spacing requirements due to vortex wake avoidance. If it can be shown that the separation requirements are too conservative, then it may be possible to increase the rate of landings on a given runway. During August/September 2003, NASA and the (United States Department of Transportation) USDOT sponsored a wake acoustics test at the Denver International Airport. The central instrument of the test was a large microphone phased array. Different types of aircrafts were recorded during landing and the acoustic data obtained was stored. From acoustic data the spectrograms were generated using the technique of AutoRegressive (AR) spectral estimation from multitaper autocorrelation estimates. Several sources of sound that are recorded in the audio files can be observed in the spectrograms. Some these signals, such as the noise generated from the aircraft engine can be identified easily because of their strength and the Doppler shift they undergo. In contrast to this, the wake vortex signal is weaker and does not exhibit a Doppler shift because it's stationary in space. Therefore it may not be identified easily because of the existence of stronger signals. The motive in our research is to develop methods to determine these strong signals that appear as spectral lines in the spectrogram. In the future, the results obtained in this work can be used to eliminate these strong signals from the spectrogram thus allowing us to see and identify wake vortex signal which is more important to us.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00012525
- Subject Headings
- Markov processes, Economics--Mathematical models, Wave structure function--Analysis, Adaptive control systems, Spectrum analysis
- Format
- Document (PDF)
- Title
- Non-destructive evaluation of reinforced asphalt pavement built over soft organic soils.
- Creator
- Pohly, Daniel D., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Research, tests and analysis are presented on several reinforcements placed in the asphalt overlay of a roadway built over soft organic soils. Non-destructive Evaluation (NDE) methods and statistical analysis were used to characterize the pavement before and after rehabilitative construction. Before reconstruction, falling weight deflectometer, rut and ride tests were conducted to evaluate the existing pavement and determine the statistical variability of critical site characteristics. Twenty...
Show moreResearch, tests and analysis are presented on several reinforcements placed in the asphalt overlay of a roadway built over soft organic soils. Non-destructive Evaluation (NDE) methods and statistical analysis were used to characterize the pavement before and after rehabilitative construction. Before reconstruction, falling weight deflectometer, rut and ride tests were conducted to evaluate the existing pavement and determine the statistical variability of critical site characteristics. Twenty-four 500ft. test sections were constructed on the roadway including sixteen reinforced asphalt and eight control sections at two test locations that possessed significantly different subsoil characteristics. NDE tests were repeated after reconstruction to characterize the improvements of the test sections. Test results were employed to quantify the stiffness properties of the pavement based on load-deflection data to evaluate the relative performance of the reinforced sections. Statistical analysis of the data showed the stiffness of the reinforced sections was consistently higher than the control sections.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/368253
- Subject Headings
- Soil remediation, Technological innovations, Structural stability, Design, Pavements, Performance, Management, Data processing, Structural analysis (Engineering)
- Format
- Document (PDF)
- Title
- Stiffness characterization and life cycle analysis of reinforced asphalt pavements using falling weight deflectometer tests.
- Creator
- Lima-Arie, Alex., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The western and northern parts of South Florida have shallow layers of organic and plastic soils under existing roads. These roads often exhibit large amount of cracking and distortion in a short period of time. Traditional repairs are often not practical due to high costs and extended construction time. In an effort to develop rehabilitation strategies that could be strictly applied to the surface layer, a pilot test site was selected along the alignment of SR 15/US 98 in northwest Palm...
Show moreThe western and northern parts of South Florida have shallow layers of organic and plastic soils under existing roads. These roads often exhibit large amount of cracking and distortion in a short period of time. Traditional repairs are often not practical due to high costs and extended construction time. In an effort to develop rehabilitation strategies that could be strictly applied to the surface layer, a pilot test site was selected along the alignment of SR 15/US 98 in northwest Palm Beach County, where severe pavement distresses were observed due to the presence of thick organic layers. PaveTrac MT-1, GlasGrid 8501, PetroGrid 4582, and ARMI were used as promising asphalt reinforcing products in 24 experimental pavement sections, including 8 control sections without any reinforcement. A comprehensive field testing and monitoring program involving FWD, rut and ride quality measurements was conducted at the preconstruction, 6-month post-construction, and 18-month post-construction stages. Due to large variability in the sub-surface conditions, a statistics-based data analysis protocol was developed for performance evaluation and relative comparisons of the test sections and, in turn, reinforcing products. Post construction data from both 6 months and 18 months demonstrated that stiffness of reinforced sections were significantly higher than the control sections. Procedures were developed to identify and statistically quantify the benefits derived from the reinforcements only, so that the relative performance of various products could be monitored over time. Based on the field testing data available to date, a framework was developed in this study for the prediction of pavement life, which is essential for conducting a detailed Life Cycle Analysis
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2976446
- Subject Headings
- Structural analysis (Engineering), Pavements, Asphalt, Performance, Management, Structural stability, Design, Pavements, Live loads, Measurement
- Format
- Document (PDF)
- Title
- Evaluation of flexible pipes under shallow burial depths.
- Creator
- Wang, Ning., Florida Atlantic University, Arockiasamy, Madasamy, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Flexible plastic and metal pipes are increasingly being used for drainage and storm sewers. When flexible pipes are buried at shallow depths, the pipe behavior will not depend on the dead load pressure above the crown, but rather on the live load pressure (vehicle load). Field tests were designed to evaluate the performance of large diameter flexible pipes of 36 in. (915 mm.) and 48 in. (1050 mm.) under shallow burial depths subjected to the actual vehicle loading. The test pipes included...
Show moreFlexible plastic and metal pipes are increasingly being used for drainage and storm sewers. When flexible pipes are buried at shallow depths, the pipe behavior will not depend on the dead load pressure above the crown, but rather on the live load pressure (vehicle load). Field tests were designed to evaluate the performance of large diameter flexible pipes of 36 in. (915 mm.) and 48 in. (1050 mm.) under shallow burial depths subjected to the actual vehicle loading. The test pipes included high-density polyethylene (HDPE) pipes, polyvinyl chloride (PVC) pipes, steel pipes and aluminum pipes. AASHTO standard pipe installation procedures were followed and pipes subjected to vehicle loads simulating the effect of HS 20-44 trucks. Measurements of interior pipe-wall strains, soil pressures at different depths and pipe deformations were taken to determine the influence of surface vehicle loads. Results of field tests are compared with those based on theoretical analyses.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12929
- Subject Headings
- Underground pipelines--Design and construction, Soil-structure interaction, Structural analysis (Engineering), Earth pressure
- Format
- Document (PDF)
- Title
- Modeling of Flexible Pipe for Culvert Application under Shallow Burial Condition.
- Creator
- Limpeteeprakarn, Terdkiat, Carlsson, Leif A., Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Flexible thermoplastic p1pes under field and laboratory loading conditions have been examined in the present study. The flexible pipes were tested under truck loading application with shallow soil cover. The pipe-soil system response includes soil stresses around and above the buried pipes, vertical pipe crown diametral strain, and circumferential pipe wall strains. Modeling the pipe-soil system is made using plane strain and thin ring assumptions. A thin ring model using Castigliano's...
Show moreFlexible thermoplastic p1pes under field and laboratory loading conditions have been examined in the present study. The flexible pipes were tested under truck loading application with shallow soil cover. The pipe-soil system response includes soil stresses around and above the buried pipes, vertical pipe crown diametral strain, and circumferential pipe wall strains. Modeling the pipe-soil system is made using plane strain and thin ring assumptions. A thin ring model using Castigliano's theorem is developed to analyze the behavior and response of a flexible pipe under well defined loading conditions and simulate the behavior of the buried pipe under the live load application. Laboratory work was carried out to study the pipe behavior and response under two-point, three-point, and four-point loading configurations. The thin ring model predictions show good agreement with classical solutions specially valid for two-point and three-point loading configurations. Laboratory results were also in good agreement with the predictions. Laboratory results show that the maximum tensile strain for the four-point loading test occurs at inner pipe crown region. Comprehensive efforts were made to correlate the thin ring model predictions with the field test results; however, it appears that the thin ring model cannot be used to simulate the effect of the live load application. A major source of the differences between the predicted and measured values is attributed to the applied load magnitude. A further investigation was carried out to examine the applicability of the model to study the general pipe behavior. The predicted hoop pipe wall strain profile was found to be similar to that of the reported strain profile by Rogers under overall poor soil support condition. Comparison of soil stress distribution shows that the 2D prediction approach provides nonconservative results while the FE analysis agrees more favorably with the measured pressure data. Overall, FE analysis shows that a linearly elastic isotropic model for the surrounding soil and flexible pipes with a fully bonded pipe-soil interface provides a reasonable prediction for soil pressures close to the buried pipes.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00012573
- Subject Headings
- Structural analysis (Engineering), Pipe, Plastic--Dynamics--Mathematical models, Underground pipelines--Design and construction, Soil-structure interaction
- Format
- Document (PDF)
- Title
- Cytotoxic cembranoids from the gorgonian Pseudopterogorgia bipinnata.
- Creator
- Wright, Amy E., Burres, N. S., Schulte, G. K.
- Date Issued
- 1989
- PURL
- http://purl.flvc.org/FCLA/DT/3353845
- Subject Headings
- Gorgonacea, Cytotoxins, Antineoplastic agents, Marine toxins, X-ray crystallography, Spectrum analysis, Chemical structure
- Format
- Document (PDF)
- Title
- Beyond sustainability: justice and complex systems thinking for just sustainable viability.
- Creator
- Best, Andrea Leigh., Dorothy F. Schmidt College of Arts and Letters, Department of Philosophy
- Abstract/Description
-
The dominant definitions of sustainability are too various and neglect essential elements necessary for effective sustainability discourse. This project considers what current understandings of sustainable development mean to those who subscribe to them and how those understandings affect public policy for sustainable development. I begin by presenting a timeline on the evolution of the term 'sustainability'. Then, I offer narrative policy analysis as a methodological tool for investigating...
Show moreThe dominant definitions of sustainability are too various and neglect essential elements necessary for effective sustainability discourse. This project considers what current understandings of sustainable development mean to those who subscribe to them and how those understandings affect public policy for sustainable development. I begin by presenting a timeline on the evolution of the term 'sustainability'. Then, I offer narrative policy analysis as a methodological tool for investigating communities of meaning with contending views on sustainability. This provides a foundation for the analysis of case studies using Harrisonian Sustainability Narratives-efficiency, equity, and ethics-as lenses through which three corresponding U.S. case studies are explored, each representing different levels of analysis-corporate, state, and individual. First, the Business Roundtable, a lobbying organization comprised of the CEOs of top U.S. companies exemplifying the efficiency narrative, claims that the problem of sustainable development can be addressed through free markets, which continually increase eco-efficiency and encourage technological advancement. Next, the Environmental Protection Agency, a state organization mandated to protect water and air and to manage toxic and solid wastes and representing the equity narrative, sees the problem of sustainable development as ensuring the just distribution of natural limits so as to reduce the impact of those limits on individuals within communities. Lastly, the ethical anthropology of Anna Peterson, philosopher of religion, points to the power of ethical narratives in creating wide-scale changes to our ideas about humanness and human nature as they relate to our relationship with our environment for sustainability., What I found in common with both the efficiency and equity narratives, representing both the political and corporate perspective and having significant influence on policy formation, is that they are pro market-based solutions of ecoefficiency and technological advancement. What they blatantly lack is guidance on what we ought to do, ought to value. I conclude that a humanist ethic is missing from both these narratives. Neither narrative sees matters of justice as co-equal partners with sustainability for sustainable development. Policy resulting from these narratives may offer efficiency and process but fails to include a robust humanist ethics necessary for a true sustainability. The way we think about our relationship to the environment shapes our behavior towards it. Just Sustainable Viability combines a complex systems approach that views human societies as complex adaptive systems and aims at optimizing social adaptive capacity with notions of distributive and procedural justice. With the inception of this new vision for sustainability, a new narrative must follow that firmly places humanity within the context of complex social and environmental systems.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2684310
- Subject Headings
- System analysis, Policy sciences, Sustainable development, Social structure, Urban ecology (Sociology)
- Format
- Document (PDF)
- Title
- Flexural Behavior of Concrete Using Basalt FRP Rebar.
- Creator
- Trotsek, Dylan, Arockiasamy, Madasamy, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The objective of this research is to determine if the deflection equations currently adopted in ACI 440.1r-15 and previously ACI 440.1r-06 accurately reflect the flexural behavior of an overreinforced Basalt Fiber Reinforced Polymer (BFRP) concrete beam. This was accomplished with experimental, analytical and numerical models. The experiment consisted of two beams doublyreinforced with BFRP rebar. A three-point flexural test on beams with a 30 in. clear span was performed and the deflections...
Show moreThe objective of this research is to determine if the deflection equations currently adopted in ACI 440.1r-15 and previously ACI 440.1r-06 accurately reflect the flexural behavior of an overreinforced Basalt Fiber Reinforced Polymer (BFRP) concrete beam. This was accomplished with experimental, analytical and numerical models. The experiment consisted of two beams doublyreinforced with BFRP rebar. A three-point flexural test on beams with a 30 in. clear span was performed and the deflections were recorded with a dial gauge and LVDT system. This data was compared to the equations from ACI 440.1r-06, ACI 440.1r-15, Branson’s equation and a numerical model created in ANSYS Mechanical APDL. Experimental results show a stiffer beam than expected when compared to the four predictive models for deflection. This can be due to the level of over-reinforcement and the small clear-span to depth ratio. Further research should be conducted to determine the cause for the additional stiffness.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004920, http://purl.flvc.org/fau/fd/FA00004920
- Subject Headings
- Reinforced concrete construction--Mathematical models., Structural analysis (Engineering), Fiber-reinforced concrete.
- Format
- Document (PDF)
- Title
- Vibration, buckling and impact of carbon nanotubes.
- Creator
- Pentaras, Demetris., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Natural frequencies of the double and triple-walled carbon nanotubes are determined exactly and approximately for both types. Approximate solutions are found by using Bubnov-Galerkin and Petrov-Galerkin methods. For the first time explicit expressions are obtained for the natural frequencies of double and triple-walled carbon nanotubes for different combinations of boundary conditions. Comparison of the results with recent studies shows that the above methods constitute quick and effective...
Show moreNatural frequencies of the double and triple-walled carbon nanotubes are determined exactly and approximately for both types. Approximate solutions are found by using Bubnov-Galerkin and Petrov-Galerkin methods. For the first time explicit expressions are obtained for the natural frequencies of double and triple-walled carbon nanotubes for different combinations of boundary conditions. Comparison of the results with recent studies shows that the above methods constitute quick and effective alternative techniques to exact solution for studying the vibration properties of carbon nanotubes. The natural frequencies of the clamped-clamped double-walled carbon nanotubes are obtained; exact solution is provided and compared with the solution reported in the literature. In contrast to earlier investigation, an analytical criterion is derived to establish the behavior of the roots of the characteristic equation. Approximate Bubnov-Galerkin solution is also obtained to compare natural frequencies at the lower end of the spectrum. Simplified version of the Bresse-Timoshenko theory that incorporates the shear deformation and the rotary inertia is proposed for free vibration study of double-walled carbon nanotubes. It is demonstrated that the suggested set yields extremely accurate results for the lower spectrum of double-walled carbon nanotube. The natural frequencies of double-walled carbon nanotubes based on simplified versions of Donnell shell theory are also obtained. The buckling behavior of the double-walled carbon nanotubes under various boundary conditions is studied. First, the case of the simply supported double-walled carbon nanotubes at both ends is considered which is amenable to exact solution., Then, approximate methods of Bubnov-Galerkin and Petrov-Galerkin are utilized to check the efficacy of these approximations for the simply supported double-walled carbon nanotubes. Once the extreme accuracy is demonstrated for simply supported conditions, the approximate techniques are applied to two other cases of the boundary conditions, namely to clamped-clamped and simply supported-clamped double-walled carbon nanotubes. For the first time in the literature approximate expression for the buckling loads are reported for these boundary conditions. The dynamic deflection of a single-walled carbon nanotube under impact loading is analyzed by following a recently study reported on the energy absorption capacity of carbon nanotubes under ballistic impact.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186764
- Subject Headings
- Nanostructured materials, Buckling (Mechanics), Plates (Engineering), Vibration, Mathematical models, Structural analysis
- Format
- Document (PDF)
- Title
- Methodology for fault detection and diagnostics in an ocean turbine using vibration analysis and modeling.
- Creator
- Mjit, Mustapha., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis describes a methodology for mechanical fault detection and diagnostics in an ocean turbine using vibration analysis and modeling. This methodology relies on the use of advanced methods for machine vibration analysis and health monitoring. Because of some issues encountered with traditional methods such as Fourier analysis for non stationary rotating machines, the use of more advanced methods such as Time-Frequency Analysis is required. The thesis also includes the development of...
Show moreThis thesis describes a methodology for mechanical fault detection and diagnostics in an ocean turbine using vibration analysis and modeling. This methodology relies on the use of advanced methods for machine vibration analysis and health monitoring. Because of some issues encountered with traditional methods such as Fourier analysis for non stationary rotating machines, the use of more advanced methods such as Time-Frequency Analysis is required. The thesis also includes the development of two LabVIEW models. The first model combines the advanced methods for on-line condition monitoring. The second model performs the modal analysis to find the resonance frequencies of the subsystems of the turbine. The dynamic modeling of the turbine using Finite Element Analysis is used to estimate the baseline of vibration signals in sensors locations under normal operating conditions of the turbine. All this information is necessary to perform the vibration condition monitoring of the turbine.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/369198
- Subject Headings
- Marine turbines, Mathematical models, Fluid dynamics, Structural dynamics, Composite materials, Mathematical models, Elastic analysis (Engineering)
- Format
- Document (PDF)
- Title
- An Empirical Study of Ordinal and Non-ordinal Classification Algorithms for Intrusion Detection in WLANs.
- Creator
- Gopalakrishnan, Leelakrishnan, Khoshgoftaar, Taghi M., Florida Atlantic University
- Abstract/Description
-
Ordinal classification refers to an important category of real world problems, in which the attributes of the instances to be classified and the classes are linearly ordered. Many applications of machine learning frequently involve situations exhibiting an order among the different categories represented by the class attribute. In ordinal classification the class value is converted into a numeric quantity and regression algorithms are applied to the transformed data. The data is later...
Show moreOrdinal classification refers to an important category of real world problems, in which the attributes of the instances to be classified and the classes are linearly ordered. Many applications of machine learning frequently involve situations exhibiting an order among the different categories represented by the class attribute. In ordinal classification the class value is converted into a numeric quantity and regression algorithms are applied to the transformed data. The data is later translated back into a discrete class value in a postprocessing step. This thesis is devoted to an empirical study of ordinal and non-ordinal classification algorithms for intrusion detection in WLANs. We used ordinal classification in conjunction with nine classifiers for the experiments in this thesis. All classifiers are parts of the WEKA machinelearning workbench. The results indicate that most of the classifiers give similar or better results with ordinal classification compared to non-ordinal classification.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00012521
- Subject Headings
- Wireless LANs--Security measures, Computer networks--Security measures, Data structures (Computer science), Multivariate analysis
- Format
- Document (PDF)