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- Title
- The social and environmental effects of shrimp mariculture: case studies of two coastal villages in Ecuador.
- Creator
- Crider, Mary C., Charles E. Schmidt College of Science, Department of Environmental Sciences
- Abstract/Description
-
Shrimp mariculture expansion in developing countries has been criticized for its ecological destruction and the resulting social conflicts. In Ecuador, shrimp pond development particularly affects rural, coastal communities. This study addresses the environmental and social effects of shrimp farming in two Ecuadorian villages, Muisne and Bunche. Interview and survey responses indicate that locals have an overall negative view of the industry. In some instances, such as increased class...
Show moreShrimp mariculture expansion in developing countries has been criticized for its ecological destruction and the resulting social conflicts. In Ecuador, shrimp pond development particularly affects rural, coastal communities. This study addresses the environmental and social effects of shrimp farming in two Ecuadorian villages, Muisne and Bunche. Interview and survey responses indicate that locals have an overall negative view of the industry. In some instances, such as increased class marginalization through reduced access to subsistence collection areas, shrimp farming directly results in conflict. However, the data also demonstrates that ponds are only one of various stressors on mangrove ecosystems. Furthermore, mariculture provides benefits to the community, including increasing employment opportunities, the local economy, and shrimp availability. In spite of these benefits, local negative perception suggests modifications to existing regulations and educational programs are necessary to minimize impacts and help the community understand the multiple factors affecting their ecosystem and livelihoods.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342043
- Subject Headings
- Mariculture, Environmental aspects, Mariculture, Social aspects, Mariculture, Economic aspects, Ecosystem management
- Format
- Document (PDF)
- Title
- Assessment of clilmate change impacts on streamflow trends using a water balance model.
- Creator
- Matthews, Kevin., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Significant changes in climate and their impacts are now visible in various places around the globe and are expected to become more evident in the coming decades. For each increase in temperature, there are environmental and societal consequences. It has important implications for existing water resources systems as well as for future water resources planning and management. Water accounting (identifying, quantifying and reporting information of water flow in a system) is the first step...
Show moreSignificant changes in climate and their impacts are now visible in various places around the globe and are expected to become more evident in the coming decades. For each increase in temperature, there are environmental and societal consequences. It has important implications for existing water resources systems as well as for future water resources planning and management. Water accounting (identifying, quantifying and reporting information of water flow in a system) is the first step towards formulating productive and sustainable water management strategies in a region. Thus, water balance models could be an empowering tool for water resource managers to prepare for and mitigate the effects of climate change on their local hydrologic resources. This thesis offers an insight into how such a tool can be used to assess and predict future stream flow trends in an effort to mitigate or manage any potential effects.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358599
- Subject Headings
- Climatic changes, Environmental aspects, Hydrology, Water resources development, Natural resources, Accounting
- Format
- Document (PDF)
- Title
- Blast/explosion resistant analysis of composite steel girder bridge system.
- Creator
- Zhou, Fang., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
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The design of bridge structures to resist explosive loads has become more of a concern to the engineering community. This thesis proposes a method to evaluate the effects of conventional blast loads on a two span continuous composite steel girder bridge system. The bridge design is based on AASHTO LRFD method. Resistance capacities of bridge deck and composite steel girder are calculated according to AASHTO specifications. Equivalent blast pressures on the bridge components are obtained....
Show moreThe design of bridge structures to resist explosive loads has become more of a concern to the engineering community. This thesis proposes a method to evaluate the effects of conventional blast loads on a two span continuous composite steel girder bridge system. The bridge design is based on AASHTO LRFD method. Resistance capacities of bridge deck and composite steel girder are calculated according to AASHTO specifications. Equivalent blast pressures on the bridge components are obtained. Response and performance of concrete deck, steel girders, and supporting piers are evaluated under typical blast loads. The blast induced force in the bridge components are computed in the static analyses for varying amounts of TNT. The blast effects in the supporting pier are determined using both static and dynamic analyses. Further research needs to be done in the dynamic analysis of the bridge system subjected to blast loads.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/227976
- Subject Headings
- Steel, Structural, Testing, Bridges, Design and construction, Structural dynamics
- Format
- Document (PDF)
- Title
- Cement stabilization of organic soils for controlling secondary compression behavior.
- Creator
- Ramirez, Juan., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Western Palm Beach County, FL is characterized by thick deposits organic soils at shallow depths. Because of their high void ratio and compressibility, these soils undergo large primary consolidation followed by extended periods of secondary compression causing excessive premature structural distress. Although soil stabilization has been largely used with remarkable results in soft, expansive and non-organic soils, limited research and practice exist in the implementation with highly organic...
Show moreWestern Palm Beach County, FL is characterized by thick deposits organic soils at shallow depths. Because of their high void ratio and compressibility, these soils undergo large primary consolidation followed by extended periods of secondary compression causing excessive premature structural distress. Although soil stabilization has been largely used with remarkable results in soft, expansive and non-organic soils, limited research and practice exist in the implementation with highly organic soils. The main motivation of this research was to investigate the effects of cement stabilization on the compressibility behavior of organic rich soils, and develop mix design criteria for optimum cement contents necessary to induce the desired engineering behavior. This optimized mix design may provide guidelines for Deep Mixing Methods in organic soils.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/367760
- Subject Headings
- Soil consolidation, Measurement, Soils, Organic compound content, Soil remediation, Technological innovations, Concrete construction, Structural stability, Design
- Format
- Document (PDF)
- Title
- Centrally prestressed fiber reinforced concrete columns.
- Creator
- Grijalba, Daniel A., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
With the need to improve corrosion resistance in columns and piles, the innovative idea of Centrally Prestressed Fiber Reinforced Concrete (CPFRC) columns is a promising solution. The first step is to compare if the compressive strength of any mix is affected by the size, geometry, or even the inclusion of polyolefin fibers in a specimen. The results showed that the cylinder size of 4 in. x 8 in., which is the most common size used by the testing labs, has the highest compressive strength....
Show moreWith the need to improve corrosion resistance in columns and piles, the innovative idea of Centrally Prestressed Fiber Reinforced Concrete (CPFRC) columns is a promising solution. The first step is to compare if the compressive strength of any mix is affected by the size, geometry, or even the inclusion of polyolefin fibers in a specimen. The results showed that the cylinder size of 4 in. x 8 in., which is the most common size used by the testing labs, has the highest compressive strength. There was no sign on compressive strength improvement with the use of polyolefin fibers, except for reduction in cracking size and concrete spalling. The second step compared the ultimate strength, ductility characteristics and failure mode of CPFRC columns to conventional columns. CPFRC showed adequate axial and flexural resistance, in addition to ductile behavior similar to regular reinforced concrete columns.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3332253
- Subject Headings
- Prestressed concrete construction, Strength of materials, Composite reinforced concrete, Concrete, Chemical resistance
- Format
- Document (PDF)
- Title
- Catastrophic event planning and response for urban areas through dynamic traffic assignment and departure time-slot allocation.
- Creator
- Degnan, William C., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Catastrophic event emergency planning has emerged as one of the most important operations management areas. Much of the successes of a response plan rely on the ability to maintain an operating transportation infrastructure. In recent years urban areas have become susceptible to biological terrorist attacks due to their size and demographics. To mitigate the devastating effects of an attack, a comprehensive catastrophic event response plan is devised. The characteristics of the disease ...
Show moreCatastrophic event emergency planning has emerged as one of the most important operations management areas. Much of the successes of a response plan rely on the ability to maintain an operating transportation infrastructure. In recent years urban areas have become susceptible to biological terrorist attacks due to their size and demographics. To mitigate the devastating effects of an attack, a comprehensive catastrophic event response plan is devised. The characteristics of the disease (dormant periods, signs/symptoms), daily traffic operations and trip distributions, patient-choice hospital modeling and emergency center corridor optimization are all elements of an effective response plan. Simulation and optimization modeling of this plan becomes a faster-than-real-time tool in replicating urban area degradation. Therefore, allowing planners to identify "worst case scenarios" within the network and implement Dynamic Traffic Assignment (DTA) techniques and a non-linear departure time slot allocation mathematical model ensuring infected populations receive treatment and/or vaccinations efficiently.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/3359332
- Subject Headings
- Emergency management, Bioterrorism, Government policy, Evacuation of civilians, Planning
- Format
- Document (PDF)
- Title
- Experimental evaluation of the durability of fly ash-based geopolymer concrete in the marine environment.
- Creator
- Edouard, Jean-Baptiste., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The construction industry is increasingly turning to the use of environmentally friendly materials in order to meet the sustainable aspect required by modern infrastructures. Consequently, for the last two decades, the expansion of this concept, and the increasing global warming have raised concerns on the extensive use of Portland cement due to the high amount of carbon dioxide gas associated with its production. The development of geopolymer concretes offers promising signs for a change in...
Show moreThe construction industry is increasingly turning to the use of environmentally friendly materials in order to meet the sustainable aspect required by modern infrastructures. Consequently, for the last two decades, the expansion of this concept, and the increasing global warming have raised concerns on the extensive use of Portland cement due to the high amount of carbon dioxide gas associated with its production. The development of geopolymer concretes offers promising signs for a change in the way of producing concrete. However, to seriously consider geopolymer binders as an alternative to ordinary Portland cement, the durability of this new material should be evaluated in any comparative analysis. The main purpose of this study was to evaluate the durability characteristics of low calcium fly ash-based geopolymer concretes subjected to the marine environment, compared to ordinary Portland cement concrete with similar exposure. To achieve this goal, 8 molar geopolymer, 14 molar geopolymer and ordinary Portland cement concrete mixes were prepared and tested for exposure in seawater. Compressive strengths in the range of 2900 to 8700 psi (20-60 MPa) were obtained. The corrosion resistance performance of steel-reinforced concrete beams, made of these mixes, was also studied, using an accelerated electrochemical method, with submergence in salt water. The test results indicated that the geopolymer concrete showed excellent resistance to chloride attack, with longer time to corrosion cracking, compared to ordinary Portland cement concrete.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3170960
- Subject Headings
- Reinforced concrete, Corrosion, Testing, Reinforced concrete construction, Concrete, Mixing, Quality control, Environmental chemistry, Industrial applications, Polymer composites
- Format
- Document (PDF)
- Title
- Evaluation of optimal real-time reflectivity-rainfall rate (Z-R) functional relationships.
- Creator
- Pattani, Kandarp., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Accuracy in estimation of precipitation can be achieved by utilizing the combination of spatial radar reflectivity data (Z) and the high resolution temporal rain gage based rainfall data (R). The study proposes the use of optimization models for optimizing the Z-R coefficients and exponents for different storm types and seasons. Precipitation data based on reflectivity, collected from National Climatic Data Center (NCDC) and rain gage data from Southwest Florida Water Management District ...
Show moreAccuracy in estimation of precipitation can be achieved by utilizing the combination of spatial radar reflectivity data (Z) and the high resolution temporal rain gage based rainfall data (R). The study proposes the use of optimization models for optimizing the Z-R coefficients and exponents for different storm types and seasons. Precipitation data based on reflectivity, collected from National Climatic Data Center (NCDC) and rain gage data from Southwest Florida Water Management District (SWFWMD) over same temporal resolutions were analyzed using the Rain-Radar- Retrieval (R3) system developed as a part of the study. Optimization formulations are proposed to obtain optimal coefficients and exponents in the Z-R relationships for different seasons and objective selection of storm-type specific Z-R relationships. Different approaches in selection of rain gage stations and selection of events for optimization are proposed using gradient based solver and genetic algorithms.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2978946
- Subject Headings
- Precipitation (Meteorology), Measurement, Rain and rainfall, Measurement, Reflectance, Rainfall intensity duration frequencies
- Format
- Document (PDF)
- Title
- Evaluation of power function approximation of NEXRAD and rain gauge based precipitation estimates.
- Creator
- Mayes-Fernandez, Mario., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Radar rainfall estimates have become a decision making tool for scientists, engineers and water managers in their tasks for developing hydrologic models, water supply planning, restoration of ecosystems, and flood control. In the present study, the utility of a power function for linking the rain gauge and radar estimates has been assessed. Mean daily rainfall data from 163 rain gauges installed within the South Florida Water Management District network have been used and their records from...
Show moreRadar rainfall estimates have become a decision making tool for scientists, engineers and water managers in their tasks for developing hydrologic models, water supply planning, restoration of ecosystems, and flood control. In the present study, the utility of a power function for linking the rain gauge and radar estimates has been assessed. Mean daily rainfall data from 163 rain gauges installed within the South Florida Water Management District network have been used and their records from January 1st, 2002 to October 31st, 2007 analyzed. Results indicate that the power function coefficients and exponents obtained by using a non-linear optimization formulation, show spatial variability mostly affected by type of rainfall events occurring in the dry or wet seasons, and that the linear distance from the radar location to the rain gauge has a significant effect on the computed values of the coefficients and exponents.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/367761
- Subject Headings
- Radar meteorology, Technological innovations, Weather forecasting, Technological innovations, Precipitation (Meteorology), Measurement, Weather control, Mathematical models
- Format
- Document (PDF)
- Title
- Collection and analyses of physical data for deep injection wells in Florida.
- Creator
- Gao, Jie., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Deep injection wells (DIW) in Florida are regulated by the U.S. Environmental Protection Agency (USEPA) and the state of Florida through the Underground Injection Control regulations contained within the Safe Drinking Water Act. Underground injection is defined as the injection of hazardous waste, nonhazardous waste, or municipal waste below the lowermost formation containing an underground source of drinking water within one-quarter mile of the wellbore. Municipalities in Florida have been...
Show moreDeep injection wells (DIW) in Florida are regulated by the U.S. Environmental Protection Agency (USEPA) and the state of Florida through the Underground Injection Control regulations contained within the Safe Drinking Water Act. Underground injection is defined as the injection of hazardous waste, nonhazardous waste, or municipal waste below the lowermost formation containing an underground source of drinking water within one-quarter mile of the wellbore. Municipalities in Florida have been using underground injection as an alternative to surface disposal of treated domestic wastewater for nearly 40 years. The research involved collecting data as of September, 2007 on all the Class I DIWs in the state of Florida and evaluating the differences between them. The analysis found regional differences in deep well practice and canonical correlation analyses concluded that depth below the USDW is the most significant factor to prevent upward migration of the injected fluid.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2796085
- Subject Headings
- Groundwater flow, Mathematical models, Artificial groundwater recharge, Groundwater, Pollution, Management, Deep-well disposal
- Format
- Document (PDF)
- Title
- Comparative analysis between the diverging diamond interchange and partial cloverleaf interchange using microsimulation modeling.
- Creator
- Galletebeitia, Borja., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
In the last decades, population growth has been outpacing transportation infrastructure growth, and today's transportation professionals are challenged to meet the mobility needs of an increasing population. The effectiveness of the transportation system is an essential constituent of people's daily lives as they commute between different points of interest. Studies show that at many highway junctions, congestion continues to worsen, and drivers are experiencing greater delays and higher risk...
Show moreIn the last decades, population growth has been outpacing transportation infrastructure growth, and today's transportation professionals are challenged to meet the mobility needs of an increasing population. The effectiveness of the transportation system is an essential constituent of people's daily lives as they commute between different points of interest. Studies show that at many highway junctions, congestion continues to worsen, and drivers are experiencing greater delays and higher risk exposures. Engineers have very little resources to handle this increase in population. One solution to resolve and alleviate congestion due to increasing traffic volumes and travel demands relies in implementing alternative designs. This approach will help traffic engineers determine which design will be the most appropriate for a particular location. This study compares and evaluates the Diverging Diamond Interchange (DDI), which is an unconventional design, to Partial Cloverleaf (ParClo) types A4 and B4 interchange designs by evaluating different Measure of Effectiveness (MOEs). Using microsimulation platform AIMSUN, each interchange type was evaluated for low, medium and high traffic flows. The analysis revealed that the DDI with four through lanes performed better than the ParClo A4 for unbalanced conditions, the DDI with six though lanes had similar results as the ParClo B4 for very high volumes. In terms of queue, the DDI design had a much better performance. The results from the analysis help in providing guidelines to the decision makers for selecting the best alternative in terms of performance.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3332256
- Subject Headings
- Roads, Interchanges and intersections, Roads, Design and construction, Traffic engineering
- Format
- Document (PDF)
- Title
- Dynamic characterization and forensic investigation of reinforced asphalt pavement cores from SR15/US98.
- Creator
- Ledezma-Campodonico, Rodrigo., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Due to the presence of deep deposits of organic soils at shallow depths, roadways in western Palm Beach County, FL show premature distress and failure requiring frequent rehabilitation. In an effort to develop effective mitigation strategies, 24 test sections, containing various types of pavement reinforcing materials, were constructed during Fall of 2008. This study presents a forensic investigation and dynamic characterization of reinforced asphalt cores obtained from SR15/US98 for...
Show moreDue to the presence of deep deposits of organic soils at shallow depths, roadways in western Palm Beach County, FL show premature distress and failure requiring frequent rehabilitation. In an effort to develop effective mitigation strategies, 24 test sections, containing various types of pavement reinforcing materials, were constructed during Fall of 2008. This study presents a forensic investigation and dynamic characterization of reinforced asphalt cores obtained from SR15/US98 for evaluating the uniformity of test sections, qualitative comparisons, and developing empirical models for predicting permanent deformation and material damage with stress cycles simulating traffic loading.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/369188
- Subject Headings
- Pavements, Asphalt, Design and construction, Roads, Design and construction, Transportation engineering
- Format
- Document (PDF)
- Title
- Development of functional relationships between radar and rain gage data using inductive modeling techniques.
- Creator
- Peters, Delroy., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Traditional methods such as distance weighing, correlation and data driven methods have been used in the estimation of missing precipitation data. Also common is the use of radar (NEXRAD) data to provide better spatial distribution of precipitation as well as infilling missing rain gage data. Conventional regression models are often used to capture highly variant nonlinear spatial and temporal relationships between NEXRAD and rain gage data. This study aims to understand and model the...
Show moreTraditional methods such as distance weighing, correlation and data driven methods have been used in the estimation of missing precipitation data. Also common is the use of radar (NEXRAD) data to provide better spatial distribution of precipitation as well as infilling missing rain gage data. Conventional regression models are often used to capture highly variant nonlinear spatial and temporal relationships between NEXRAD and rain gage data. This study aims to understand and model the relationships between radar (NEXRAD) estimated rainfall data and the data measured by conventional rain gages. The study is also an investigation into the use of emerging computational data modeling (inductive) techniques and mathematical programming formulations to develop new optimal functional approximations. Radar based rainfall data and rain gage data are analyzed to understand the spatio-temporal associations, as well as the effect of changes in the length or availability of data on the models. The upper and lower Kissimmee basins of south Florida form the test-bed to evaluate the proposed and developed approaches and also to check the validity and operational applicability of these functional relationships among NEXRAD and rain gage data for infilling of missing data.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/166454
- Subject Headings
- Weather control, Mathematical models, Radar meteorology, Technological innovations, Precipitation (Meteorology), Measurement, Weather forecasting, Technological innovations
- Format
- Document (PDF)
- Title
- Durability prediction of recycled aggregate concrete under accelerated aging and environmental exposure.
- Creator
- Gonzalez, Lillian, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
This study is to compare the performance of recycled aggregate concrete and the impact of up to 50% cement replacement with fly ash on durability. Water content, sieve analysis, standard and modified compaction tests were performed to assess the physical properties of the recycled aggregate concrete. Accelerated aging tests were performed to predict the long term durability of the recycled aggregate concrete. Following Arrhenius modeling and TTS and SIM accelerated aging protocols, a time...
Show moreThis study is to compare the performance of recycled aggregate concrete and the impact of up to 50% cement replacement with fly ash on durability. Water content, sieve analysis, standard and modified compaction tests were performed to assess the physical properties of the recycled aggregate concrete. Accelerated aging tests were performed to predict the long term durability of the recycled aggregate concrete. Following Arrhenius modeling and TTS and SIM accelerated aging protocols, a time versus stiffness master curve was created. This allowed the prediction of equivalent age using experimental data and theoretical analysis. To account for environmental exposure, the specimens underwent 24 and 48 hours of wet-dry cycling and subjected. Overall there was an increase in stiffness and strength from the specimens containing fly ash. All tests performed predicted equivalent age beyond the testing period of 144 hrs. and up to 7 years. Specimens containing fly maintained a constant and higher density to environmental exposure.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/3353087
- Subject Headings
- Concrete, Mechanical properties, Testing, Concrete, Environmental aspects, Sustainable construction, High strength concrete, Testing, Cement composites, Testing
- Format
- Document (PDF)
- Title
- Farfield modeling of the Boynton Inlet plume using sulfur hexafluoride as tracer.
- Creator
- Pire-Schmidt, Joaquin., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
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The analysis and modeling of the coastal farfield behavior of inlet discharge plumes is the key to understanding the fate of pollutants discharged into the ocean. These plumes disperse in chaotic and unpredictable patterns. Theoretical models are based on the average conditions and calibrated to the results of tracer studies. Data and models for freshwater discharges in coastal ocean systems are limited because of the lack of adequate tracers. On February, 2007, a tracer study was conducted...
Show moreThe analysis and modeling of the coastal farfield behavior of inlet discharge plumes is the key to understanding the fate of pollutants discharged into the ocean. These plumes disperse in chaotic and unpredictable patterns. Theoretical models are based on the average conditions and calibrated to the results of tracer studies. Data and models for freshwater discharges in coastal ocean systems are limited because of the lack of adequate tracers. On February, 2007, a tracer study was conducted on the Boynton Inlet, Florida, using sulfur hexafluoride (SF6) tracer. The objective of this study is to provide methods of analysis for the sample data collected during the experiment. The detected tracer concentrated in a bolus that migrated north of the inlet at velocities lower than predicted by the current data. The plume was successfully modeled with a Gaussian plume model, with 90% of the SF6 predictions having less than 4.6 pptr error.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186771
- Subject Headings
- Plumes (Fluid dynamics), Water, Pollution, Sedimentation and deposition, Environmental aspects, Pollution, Mathematical models
- Format
- Document (PDF)
- Title
- Effect of median grain size ratio on the compaction behavior of binary granular mixes.
- Creator
- Brenner, Tara Devine., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Optimization of compaction in granular material without the use of traditional ground improvement methods may be possible by optimizing the percentage of finer material and the median grain size ratio in binary soil mixtures. In this study, the median grain size ratio D50/d50 was explored as a fundamental parpmeter affecting the compaction characteristics of binary mixes made from natural sands as opposed to singular measurements such as fines content and mean grain size traditionally used to...
Show moreOptimization of compaction in granular material without the use of traditional ground improvement methods may be possible by optimizing the percentage of finer material and the median grain size ratio in binary soil mixtures. In this study, the median grain size ratio D50/d50 was explored as a fundamental parpmeter affecting the compaction characteristics of binary mixes made from natural sands as opposed to singular measurements such as fines content and mean grain size traditionally used to represent granular soils. A total of 18 binary granular mixes were synthetically generated from natural sands obtained from Longboat Key, Florida and evaluated through grain size analysis, laboratory compaction and determination of relative density. Results indicate that the D50/d50 ratio shows promise as a fundamental parameter for compaction optimization in binary mixes with values exceeding six approaching the densest packing configuations.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358329
- Subject Headings
- Granular materials, Dynamic testing, Engineering geology, Soil mechanics, Testing, Micromechanics, Mathematical models
- Format
- Document (PDF)
- Title
- Advanced methods in sea level rise vulnerability assessment.
- Creator
- Romah, Thomas., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Increasing sea levels have the potential to place important portions of the infrastructure we rely on every day at risk. The transportation infrastructure relies on roads, airports, and seaports to move people, services, and goods around in an ever connected global economy. Any disturbances of the transportation modes have reverberating effects throughout the entire economic spectrum. The effects include delays, alterations of routes, and possible changes in the origin and destinations of...
Show moreIncreasing sea levels have the potential to place important portions of the infrastructure we rely on every day at risk. The transportation infrastructure relies on roads, airports, and seaports to move people, services, and goods around in an ever connected global economy. Any disturbances of the transportation modes have reverberating effects throughout the entire economic spectrum. The effects include delays, alterations of routes, and possible changes in the origin and destinations of services and goods. The purpose of this project is to develop an improved methodology for a sea level rise scenario vulnerability assessment model. This new model uses the groundwater elevation as a limiting factor for soil storage capacity in determining previously underestimated areas of vulnerability. The hope is that early identification of vulnerability will allow planners and government officials an opportunity to identify and either remediate or create alternative solutions for vulnerable land areas before high consequence impacts are felt.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358965
- Subject Headings
- Sea level, Environmental aspects, Coastal zone management, Sea level, Climactic factors, Climate change mitigation, Climatic changes, Risk management
- Format
- Document (PDF)
- Title
- Influences of climate variability and change on precipitation characteristics and extremes.
- Creator
- Goly, Aneesh, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
This study focuses on two main broad areas of active research on climate: climate variability and climate change and their implications on regional precipitation characteristics. All the analysis is carried out for a climate change-sensitive region, the state of Florida, USA. The focus of the climate variability analysis is to evaluate the influence of individual and coupled phases (cool and warm) of Atlantic multidecadal oscillation (AMO) and El Niäno southern oscillation (ENSO) on regional...
Show moreThis study focuses on two main broad areas of active research on climate: climate variability and climate change and their implications on regional precipitation characteristics. All the analysis is carried out for a climate change-sensitive region, the state of Florida, USA. The focus of the climate variability analysis is to evaluate the influence of individual and coupled phases (cool and warm) of Atlantic multidecadal oscillation (AMO) and El Niäno southern oscillation (ENSO) on regional precipitation characteristics. The two oscillations in cool and warm phases modulate each other which have implications on flood control and water supply in the region. Extreme precipitation indices, temporal distribution of rainfall within extreme storm events, dry and wet spell transitions and antecedent conditions preceding extremes are evaluated. Kernel density estimates using Gaussian kernel for distribution-free comparative analysis and bootstrap sampling-based confidence intervals are used to compare warm and cool phases of different lengths. Depth-duration-frequency (DDF) curves are also developed using generalized extreme value (GEV) distributions characterizing the extremes. ... This study also introduces new approaches to optimally select the predictor variables which help in modeling regional precipitation and further provides a mechanism to select an optimum spatial resolution to downscale the precipitation projections. New methods for correcting the biases in monthly downscaled precipitation projections are proposed, developed and evaluated in this study. The methods include bias corrections in an optimization framework using various objective functions, hybrid methods based on universal function approximation and new variants.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362383
- Subject Headings
- Climatic changes, Environmental aspects, Global temperature changes, Environmental aspects, Precipitation (Meteorology), Measurement, Bootstrap (Statistics)
- Format
- Document (PDF)
- Title
- Numerical simulation and prediction of loads in marine current turbine full-scale rotor blades.
- Creator
- Senat, Junior., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
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Marine current turbines are submerged structures and subjected to loading conditions from both the currents and wave effects. The associated phenomena posed significant challenge to the analyses of the loading response of the rotor blades and practical limitations in terms of device location and operational envelopes. The effect of waves on marine current turbines can contribute to the change of flow field and pressure field around the rotor and hence changes the fluid forces on the rotor....
Show moreMarine current turbines are submerged structures and subjected to loading conditions from both the currents and wave effects. The associated phenomena posed significant challenge to the analyses of the loading response of the rotor blades and practical limitations in terms of device location and operational envelopes. The effect of waves on marine current turbines can contribute to the change of flow field and pressure field around the rotor and hence changes the fluid forces on the rotor. However, the effect of the waves on the rotor depends on the magnitude and direction of flow velocity that is induced by the waves. An analysis is presented for predicting the torque, thrust, and bending moments resulting from the wave-current interactions at the root of rotor blades in a horizontal axis marine current turbine using the blade element-momentum (BEM) theory combined with linear wave theory. Parametric studies are carried out to better understand the influence of important parameters , which include wave height, wave frequency, and tip-speed ratio on the performance of the rotor. The periodic loading on the blade due to the steady spatial variation of current speeds over the rotor swept area is determined by a limited number of parameters, including Reynolds number, lift and drag coefficients, thrust and torque coefficients, and power coefficient. The results established that the BEM theory combined with linear wave theory can be used to analyze the wavecurrent interactions in full-scale marine current turbine. The power and thrust coefficients can be analyzed effectively using the numerical BEM theory in conjunction with corrections to the tip loss coefficient and 3D effects., It has been found both thrust and torque increase as the current speed increases, and in longer waves the torque is relatively sensitive to the variation of wave height. Both in-plane and out-of-plane bending moments fluctuate significantly and can be predicted by linear wave theory with blade element-momentum theory.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3172695
- Subject Headings
- Marine turbines, Mathematical models, Structural dynamics, Fluid dynamics, Rotors, Design and construction
- Format
- Document (PDF)
- Title
- Nanotechology in concrete: review and statistical analysis.
- Creator
- Glenn, Jonathan., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
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This thesis investigates the use of nanotechnology in an extensive literature search in the field of cement and concrete. A summary is presented. The research was divided into two categories: (1) nanoparticles and (2) nanofibers and nanotubes. The successes and challenges of each category is documented in this thesis. The data from the literature search is taken and analyzed using statistical prediction by the use of the Monte Carlo and Bayesian methods. It shows how statistical prediction...
Show moreThis thesis investigates the use of nanotechnology in an extensive literature search in the field of cement and concrete. A summary is presented. The research was divided into two categories: (1) nanoparticles and (2) nanofibers and nanotubes. The successes and challenges of each category is documented in this thesis. The data from the literature search is taken and analyzed using statistical prediction by the use of the Monte Carlo and Bayesian methods. It shows how statistical prediction can be used to analyze patterns and trends and also discover optimal additive dosages for concrete mixes.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3360786
- Subject Headings
- Nanostructured materials, Nanofibers, Cement, Additives, Concrete, Additives
- Format
- Document (PDF)