View All Items
(1 - 20 of 38)
Pages
- Title
- AN EXPLORATION OF GENDER IMPACTS THROUGH THE PORTRAYAL OF TEACHERS IN BEST SELLING PICTUREBOOKS, 2008-2012.
- Creator
-
Martinez, Alicia, Roberts, Sherron, University of Central Florida
- Abstract / Description
-
The purpose of this study is to examine if a difference exists in the quantity and/or quality, in terms of effectiveness in the portrayal of teachers, and according to gender, in New York Times best selling picturebooks, 2008 to 2012. This study examines the depiction of a teacher in terms of their effectiveness, as defined by Robert Walker's 12 Characteristics of an effective teacher. Examining each of the portrayed teachers for both the 12 effective characteristics, as well as their direct...
Show moreThe purpose of this study is to examine if a difference exists in the quantity and/or quality, in terms of effectiveness in the portrayal of teachers, and according to gender, in New York Times best selling picturebooks, 2008 to 2012. This study examines the depiction of a teacher in terms of their effectiveness, as defined by Robert Walker's 12 Characteristics of an effective teacher. Examining each of the portrayed teachers for both the 12 effective characteristics, as well as their direct antithesis, presents a clear image of the teachers presented to young audiences through picturebooks. In addition to comparing the presentation of a male teacher as opposed to a female teacher, this study revealed the depiction of teachers to be one who is almost always female, generally prepared, creative, and positive. Educational implications for choosing picturebooks and highlighting positive qualities to children are also provided.
Show less - Date Issued
- 2014
- Identifier
- CFH0004608, ucf:45312
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004608
- Title
- IMPACT OF CONSTRUCTION ON FREEWAY TRAFFIC OPERATIONS.
- Creator
-
Jagtap, Seema, Al-Deek, Haitham, University of Central Florida
- Abstract / Description
-
This study provides an insight into the impact of construction activities on traffic operations. Specifically, the topic of interest for this thesis is to study the impact of construction on traffic operations for construction projects on Interstate 4 from SR 434 to John Young Parkway, from SR 528 to SR 535, and from SR 482 to SR 528. These three projects were chosen because they were the only projects on Interstate 4 where both construction data and loop detector data were available for...
Show moreThis study provides an insight into the impact of construction activities on traffic operations. Specifically, the topic of interest for this thesis is to study the impact of construction on traffic operations for construction projects on Interstate 4 from SR 434 to John Young Parkway, from SR 528 to SR 535, and from SR 482 to SR 528. These three projects were chosen because they were the only projects on Interstate 4 where both construction data and loop detector data were available for analysis. The data was collected by examining the Florida Department of Transportation daily inspection reports which had detailed documentation of construction operations that took place. The following information was collected: date, type of construction work being performed, time, location, and direction of impact to the traveling public. These data points were cross-referenced to the loop detector stations and mile posts to collect the loop detector data and roadway geometric characteristics such as location of ramps, type of median, etc. The loop detector data (speed, volume, and occupancy) were collected and aggregated for the data analysis. The loop detector data were collected during construction, one year prior to construction, and one year after construction for comparison purposes. Logistic regression analysis under the within-stratum matched sampling framework was conducted as an exploratory analysis to see if there was a difference on the traffic impacts with and without construction. This was done by matching the variables to ensure that there were no other differences impacting the traffic operations. Logistic regression proved there was a difference in the traffic operations with and without the presence of construction. The simple model results demonstrated that speed was reduced, occupancy was increased, and volume decreased during construction. After construction, the speed and volume increased and the occupancy decreased. Linear regression and analysis of covariance were used to quantify the impact of the various construction activities on the speed, occupancy and volume. Linear regression and analysis of covariance were used to understand the impacts from the presence of roadway geometrics on freeway traffic operations during construction. Logistic regression controls the geometrics, linear regression and analysis of covariance demonstrated how the geometrics impacted the construction effects. The geometric characteristics of each area were included in this analysis. This thesis investigates construction activities and roadway geometric parameters that impact traffic freeway operations (speed, volume, and occupancy) before, during, and after construction. This research showed the impact of different types of construction operations in a highway construction widening project. This research demonstrated that construction activities have a significant impact on speed, volume, and occupancy. Different types of construction activities have more of an impact than other activities. Paving had the highest adverse impact. Agencies writing construction contracts should prohibit paving during the most highly congested times. For example, in Orlando, Florida on Interstate 4, agencies should prohibit night paving during the peak holiday seasons (such as Thanksgiving, spring breaks, Christmas, etc.) around the tourist attractions during closing times, during the peak morning hours, and during the closing times of high attendance activities, such as Halloween Horror Nights at Universal Studios when high attendance is anticipated at the theme parks. Roadway geometrics also impact the traffic operations differently, before, during, and after construction and differently during various times of the day. The information of improved roadway geometrics and faster traffic flow can be used at open houses for upcoming projects where there are many people opposed to construction projects to show how the roadway construction projects actually increase traffic flow, helping everyone to get to their destinations much faster. The impact of the traffic delays in the congested areas, such as the tourist areas on Interstate 4 during the peak traffic times could be quantified to calculate delay costs to the roadway users.
Show less - Date Issued
- 2008
- Identifier
- CFE0002201, ucf:47887
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002201
- Title
- An Analysis of the Impact of K-12 Educational Leadership Program Graduates: 1992-2012.
- Creator
-
Bennett, Roseann, Taylor, Rosemarye, Baldwin, Lee, Doherty, Walter, Thedy, Elizabeth, University of Central Florida
- Abstract / Description
-
This study addressed the problem of insufficient information concerning the economic and professional impact of educational leadership program graduates. In Florida, there is often times a delay in obtaining an administrative appointment after graduating from an educational leadership program. The delay in appointments causes difficulty with tracking careers and economic impact. The research questions were:1.What is the economic impact of activities, projects, and research performed by 1992...
Show moreThis study addressed the problem of insufficient information concerning the economic and professional impact of educational leadership program graduates. In Florida, there is often times a delay in obtaining an administrative appointment after graduating from an educational leadership program. The delay in appointments causes difficulty with tracking careers and economic impact. The research questions were:1.What is the economic impact of activities, projects, and research performed by 1992 to 2012 graduates while enrolled in the educational leadership program? 2.How many educational leadership program graduates from 1992 to 2012 were appointed or elected to superintendent positions, senior staff or superintendent's cabinet, or school district level director positions (using the 2012-2013 school district student enrollment size rankings)?3.How many educational leadership program graduates from 1992 to 2012 were appointed to principal or assistant principal positions in the selected school districts (using the 2012-2013 school district student enrollment size rankings)?4.What are the Florida School Grade trends among educational leadership program graduates from 1992 to 2012 of a large urban research university in Florida who were school principals? This study utilized descriptive statistics and was designed to analyze program performance outcomes delivered by graduates of a large urban research university's educational leadership program (1992-2012) and their responses to a survey. The value of activities, projects, and research completed while enrolled in the educational leadership graduate program was determined to arrive at economic impact. Graduates were matched with administrative positions including K-12 superintendent, senior staff or superintendent's cabinet, school district level directors, public school principal or assistant principal. In addition, Florida school grades for those graduates that held principal positions in a specific geographical area during the 1998-2012 period were identified. Measures of central tendency and descriptive statistics were conducted, as appropriate, for each of the four research questions. Research findings indicated there were data to support that while enrolled in the educational leadership graduate program, economic impact was provided to school districts. Furthermore, graduates who were identified as principals in K-12 public schools had student outcomes that outperformed the state average as indicated by school grades. The data trend of meeting high expectations determined by student achievement results increased each year as evidenced by a greater number of schools earning (")A(") grades. Recommendations made for future research were for universities to create and maintain a university database and survey graduates to gather data. The data would be used to align the preparation program curricular and instructional practices with the professional experiences needed to prepare leaders to be position ready. Additionally, universities must continuously communicate with graduates in order to evaluate the effectiveness of the preparation program, measure economic impact and capture career paths. This would be performed through a longitudinal study.
Show less - Date Issued
- 2016
- Identifier
- CFE0006440, ucf:51483
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006440
- Title
- STICKS AND STONES: AN ANALYSIS OF THE IMPACT DOCTRINE IN FLORIDA.
- Creator
-
Cuza, Carmen, Cook, Kathy, University of Central Florida
- Abstract / Description
-
Within the last few decades, public opinion has greatly shaped the justice system to prevent "slippery slopes". This is most evident in the common law doctrine that restricts an alleged victim for recovering damages of emotional distress without notable physical manifestation in the eyes of a layperson�The Impact Doctrine. However, emotional distress is manifested in many psychological illnesses that do not require physical injury that are recognized as legitimate in psychology. This research...
Show moreWithin the last few decades, public opinion has greatly shaped the justice system to prevent "slippery slopes". This is most evident in the common law doctrine that restricts an alleged victim for recovering damages of emotional distress without notable physical manifestation in the eyes of a layperson�The Impact Doctrine. However, emotional distress is manifested in many psychological illnesses that do not require physical injury that are recognized as legitimate in psychology. This research explores the history of the rule and how it is inconsistent with not only areas of science; but also, other areas of the law. The purpose of this thesis is to explore alternatives to The Impact Doctrine. Through analysis of American common law, Florida common law, and British common law, it can be concluded that the British have found the best alternative to the rule that helps prevent "slippery slopes", while also bridging the gap between science and the law. By analyzing the LGBT (Lesbian, Gay, Bisexual, and Transgender) community and Civil Rights Actions, the LGBT community may bring a suit for emotional distress based upon a Civil Rights action.
Show less - Date Issued
- 2016
- Identifier
- CFH2000037, ucf:45583
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000037
- Title
- The Missing Middle: Understanding the Effects of Social Enterprise on Nonprofit Performance.
- Creator
-
White-Jones, Angela, Feder, Lynette, Stevenson, Robyne, Norris Tirrell, Dorothy, Nobles, Matt, University of Central Florida
- Abstract / Description
-
The 2008 financial recession has seen increased poverty, job loss, and homelessness as well as decreased spending in health care, education, sanitation, and housing. These factors can lead to tensions across a number of sectors and underscore the need for innovation in for-profit, nonprofit and government organizations. One area of innovation in the nonprofit sector to supplement revenues is by adding social enterprise activity. Social enterprise is the pursuit of earned income activities for...
Show moreThe 2008 financial recession has seen increased poverty, job loss, and homelessness as well as decreased spending in health care, education, sanitation, and housing. These factors can lead to tensions across a number of sectors and underscore the need for innovation in for-profit, nonprofit and government organizations. One area of innovation in the nonprofit sector to supplement revenues is by adding social enterprise activity. Social enterprise is the pursuit of earned income activities for an organization that is driven by a community mission or value.Because financial and social problems are becoming increasingly intertwined, this study seeks to understand the impacts of social enterprises on nonprofit organizations. The research uses existing data from Guidestar based on nonprofit IRS Form 990 as well as responses to an original survey administered to nonprofit organizations throughout Florida. This study will indicate if there are financial and social impacts on nonprofit organizations that have a social enterprise.Multiple regression analysis is used to estimate the impact of social enterprises on their respective nonprofits. Examining financial and social outcomes, the study determines the impact of social enterprises on a nonprofit's finances and mission.
Show less - Date Issued
- 2016
- Identifier
- CFE0006419, ucf:51456
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006419
- Title
- Cities of Service: A Grounded Theory Exploration of Volunteer Service.
- Creator
-
Hill, Brandy, Martin, Lawrence, Bryer, Thomas, Kapucu, Naim, Wan, Thomas, University of Central Florida
- Abstract / Description
-
This research explores how volunteer service can be both included and impactful in strategies to address local challenges. Prior research would suggest that volunteer service has largely been overlooked when it comes to governmental efforts to solve society's biggest problems, particularly at the local level. Ignoring the potential for volunteer service in problem-solving approaches may hinder the development of effective problem-solving strategies. This research describes the ways cities...
Show moreThis research explores how volunteer service can be both included and impactful in strategies to address local challenges. Prior research would suggest that volunteer service has largely been overlooked when it comes to governmental efforts to solve society's biggest problems, particularly at the local level. Ignoring the potential for volunteer service in problem-solving approaches may hinder the development of effective problem-solving strategies. This research describes the ways cities drive demand for volunteer service. In particular, volunteer service demand can be explained through certain motivational bases(-)economic, aspirational, and need-based(-)together with various feasibility considerations. A grounded theory model for volunteer service demand from the perspective of the city and a generalized logic model for service as a strategy to address local challenges are presented.
Show less - Date Issued
- 2013
- Identifier
- CFE0004690, ucf:49849
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004690
- Title
- Long-term Carbon and Copper Impact on Nutrient Removal via Green Sorption Media in Dynamic Linear Ditch Environments.
- Creator
-
Ordonez, Diana, Chang, Ni-bin, Randall, Andrew, Sadmani, A H M Anwar, University of Central Florida
- Abstract / Description
-
Nutrient-laden stormwater runoff causes environmental and ecological impacts on receiving water bodies. Biosorption Activated Media (BAM) composed of the sand, tire crumb, and clay have been implemented in stormwater best management practices due to its ability to efficiently remove nutrients from stormwater runoff, such as in roadside linear ditches, via unique chemophysical and microbiological processes. In this study, a set of fixed-bed columns were set up to simulate some external forces...
Show moreNutrient-laden stormwater runoff causes environmental and ecological impacts on receiving water bodies. Biosorption Activated Media (BAM) composed of the sand, tire crumb, and clay have been implemented in stormwater best management practices due to its ability to efficiently remove nutrients from stormwater runoff, such as in roadside linear ditches, via unique chemophysical and microbiological processes. In this study, a set of fixed-bed columns were set up to simulate some external forces in roadside linear ditches and examine how these external forces affect the performance of BAM. In our experiment, scenario 1 simulates the impact that animals such as tortoises, moles and ants produce conduits on the top layer of BAM. Scenario 2 simulates the presence of animals on BAM, together with external compaction. Finally, scenario 3 simulates external compaction such as traffic compaction alone. Furthermore, two baseline conditions were included to sustain the impact assessment of these three scenarios, respectively. They are the long-term presence of carbon in stormwater as carbon can be transported by stormwater runoff from neighboring crop fields, and the long-term presence of copper ions in stormwater as copper depositions can also be found because of electrical wiring, roofing, stormwater ponds disinfection and automobile brake pads in transportation networks. This systematic assessment encompasses some intertwined field complexity in real world systems driven by different hydraulic conditions, microbial ecology, Dissolved Organic Nitrogen (DON) reshape/removal, and long-term addition of carbon and copper (alone) on the effectiveness of total nitrogen removal. The removal efficiencies are substantially linked to varying microbial processes including mineralization, ammonification, nitrification, denitrification, and even dissimilatory nitrate reduction to ammonium, each of which is controlled by different dominant microbial species. The identification of DON compounds at the molecular level was done via a Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-IR-MS) whereas the quantitation of microbial species was done by using quantitative Polymerase Chain Reaction (qPCR). The results from the interactions between microbial ecology and DON decomposition were compared to the external forces and baseline conditions to obtain a holistic understanding of the removals efficiencies of total nitrogen. With the aid of qPCR and FT-IR-MS, this study concluded that the long-term presence of carbon is beneficial for nutrient removal whereas the long-term copper addition inhibits nutrient removal.
Show less - Date Issued
- 2019
- Identifier
- CFE0007847, ucf:52816
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007847
- Title
- A Study to Determine the Degree of Fairness Resulting from Section 8002 of the Federal Impact Aid Program on Qualifying Local Education Agencies.
- Creator
-
Thomas, Danielle, Murray, Barbara, Murray, Kenneth, Doherty, Walter, Lynn, Evelyn, University of Central Florida
- Abstract / Description
-
Educational funding is a topic of much focus given the impact school budgets have on instructional decisions and school programs. The purpose of this study was to analyze the funding received by Local Education Agencies (LEAs) from Section 8002 of the Program to determine how the amount received equates to the local property tax from the land assessment. In addition, comparisons were drawn as to how the amounts between LEAs equate within a state and across states. Through the use of...
Show moreEducational funding is a topic of much focus given the impact school budgets have on instructional decisions and school programs. The purpose of this study was to analyze the funding received by Local Education Agencies (LEAs) from Section 8002 of the Program to determine how the amount received equates to the local property tax from the land assessment. In addition, comparisons were drawn as to how the amounts between LEAs equate within a state and across states. Through the use of qualitative data received from the United States Department of Education regarding the amount paid to LEAs during fiscal years 2011 through 2015 as well projected property tax amounts calculated by the researcher, inequities were discovered between LEAs within states as well as across states. Significant deficiencies were discovered between projected property tax and the amount of impact aid received across most of the receiving LEAs. In addition, a large number of inequities were discovered between receiving LEAs across the same state with a significant number of inequities also occurring across LEAs in different states. These findings meant many LEAs had greatly reduced school district budgets which has a significant impact on the programs and services that can be funded for students.
Show less - Date Issued
- 2016
- Identifier
- CFE0006404, ucf:51482
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006404
- Title
- FACTORS RELATED TO STRESS IN NURSING STUDENTS.
- Creator
-
Shultz, Marie, Covelli, Maureen, University of Central Florida
- Abstract / Description
-
The purpose of this review of literature was to explore and critically analyze relevant literature regarding stress factors and the consequences of stress in nursing students. Findings from this review of literature aimed to provide a better understanding of stress factors and the physical and psychological impact of stress on nursing students. Information was collected from the Cumulative Index to Nursing and Allied Health Literature, PsycINFO, and MEDLINE- EBSCOhost databases to explore...
Show moreThe purpose of this review of literature was to explore and critically analyze relevant literature regarding stress factors and the consequences of stress in nursing students. Findings from this review of literature aimed to provide a better understanding of stress factors and the physical and psychological impact of stress on nursing students. Information was collected from the Cumulative Index to Nursing and Allied Health Literature, PsycINFO, and MEDLINE- EBSCOhost databases to explore what research has been conducted and to assess the current knowledge base. Analysis of the literature indicated that nursing students reported experiencing increased levels of stress during the academic year. Nursing students reported higher levels of stress in conjunction with elevated external stressors, including increased responsibilities and course requirements. Analysis of the findings suggested that factors related to stress in nursing students arose from clinical sources, academic sources, and personal sources. Further analysis indicated that experiencing elevated levels of stress had a negative impact on the student. Increased levels of stress, combined with poor coping mechanisms, may lead to poor academic performance and burn-out among nursing students. Future research may evaluate means to reduce stress levels and mitigate stress in nursing students through targeting specific causative factors. Findings from this review of literature aim to influence student management of stress.
Show less - Date Issued
- 2011
- Identifier
- CFH0003825, ucf:44778
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0003825
- Title
- WHAT IS THE EFFECT OF STANDARDIZED TESTING ON TEACHER PRACTICE?.
- Creator
-
Granato, Courtney, Hopp, Carolyn, University of Central Florida
- Abstract / Description
-
This study examines the potential correlation between standardized testing and teacher practice. Building upon the conceptual framework, are constructs of school climate and assessment to develop themes such as leadership role, teacher role, district role, and coach's role as well as teacher practice, classroom assessment, standardized assessment, and the alignment of curriculum to standardized testing. In discovering the parallel between standardized testing and teacher practice, both...
Show moreThis study examines the potential correlation between standardized testing and teacher practice. Building upon the conceptual framework, are constructs of school climate and assessment to develop themes such as leadership role, teacher role, district role, and coach's role as well as teacher practice, classroom assessment, standardized assessment, and the alignment of curriculum to standardized testing. In discovering the parallel between standardized testing and teacher practice, both qualitative and quantitative data were collected through research and observations, but more importantly through a survey and focus group. Over a two-semester period, it became evident that there was an eminent parallel between each the themes and constructs within the conceptual framework, ultimately answering the research question. Although the data fulfilled the research question of this study, future research would require a more in-depth, longitudinal study in order to suggest possible ideas for solutions.
Show less - Date Issued
- 2015
- Identifier
- CFH0004790, ucf:45335
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004790
- Title
- USING A CONTINGENCY-BASED METHOD FOR COMBINING INDIVIDUAL ASSESSMENT CENTER DIMENSION RATINGS INTO OVERALL ASSESSMENT RATINGS.
- Creator
-
Wicks, Keisha, Pritchard, Robert, University of Central Florida
- Abstract / Description
-
The current study applies a newly proposed mechanical combination method along with four traditional mechanical combination methods to assessment center scoring. These comparisons were made for two job levels (Fire Lieutenant and Fire Captain). The study further assesses the level of adverse impact for the various methods at three cut-off scores. Results indicated that the new contingency-based scoring method was successfully implemented in the assessment center. Results were mixed regarding...
Show moreThe current study applies a newly proposed mechanical combination method along with four traditional mechanical combination methods to assessment center scoring. These comparisons were made for two job levels (Fire Lieutenant and Fire Captain). The study further assesses the level of adverse impact for the various methods at three cut-off scores. Results indicated that the new contingency-based scoring method was successfully implemented in the assessment center. Results were mixed regarding whether the contingencies developed for the two job levels were different. Further, results indicated that although the various combination methods were highly correlated as expected, there were clear distinctions in the decisions made based on the different combination methods. Specifically, the various combination methods resulted in different candidates comprising the qualifying cut-off ranks. Finally, results showed that the contingency-based method had less adverse impact overall when compared to the other four methods. Future research is proposed in addition to a discussion of the limitations of the study. The main limitation was a lack of criterion data.
Show less - Date Issued
- 2008
- Identifier
- CFE0002315, ucf:47852
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002315
- Title
- Comparative nutrient removal with innovative green soprtion media for groundwater and stormwater co-treatment.
- Creator
-
Wen, Dan, Chang, Ni-bin, Nam, Boo Hyun, Kibler, Kelly, Wanielista, Martin, Zheng, Qipeng, University of Central Florida
- Abstract / Description
-
As indicated by the National Academy of Engineering, the understanding of nitrogen cycle has been deemed as one of 14 grand challenges in engineering of the 21st century. Due to rapid population growth and urbanization, the stormwater runoff increased in quantity as well as its nutrient concentrations, which may trigger serious environmental issues such as eutrophication in aquatic systems and ecosystem degradation. This study focuses on stormwater and groundwater quality control via...
Show moreAs indicated by the National Academy of Engineering, the understanding of nitrogen cycle has been deemed as one of 14 grand challenges in engineering of the 21st century. Due to rapid population growth and urbanization, the stormwater runoff increased in quantity as well as its nutrient concentrations, which may trigger serious environmental issues such as eutrophication in aquatic systems and ecosystem degradation. This study focuses on stormwater and groundwater quality control via Biosorption Activated Media (BAM) which can be applied to enhance the nutrient removal potential as an emerging Best Management Practices (BMPs). BAM was tested in this study with respect to two changing environmental factors including the presence of toxins such as copper and the addition of carbon sources that may affect the removal effectiveness. In addition, the impacts on microbial ecology in BAM within the nitrification and denitrification processes due to those changing environmental conditions were explored through the identification of microbial population dynamics under different environmental conditions. To further enhance the recovery and reuse of the adsorbed ammonia as possible soil amendment or even fertilizer, a new media called Iron Filing Green Environmental Media (IFGEM) was developed based on BAM, with the inclusion of iron filings as a key component for nitrate reduction. The functionality of IFGEM was analyzed through a serious column studies with respect to several key factors, including varying influent nutrient concentrations, pH values, and temperature. The results of the column studies demonstrate promising nutrient removal and recovery potential simultaneously under changing factors.
Show less - Date Issued
- 2018
- Identifier
- CFE0007770, ucf:52394
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007770
- Title
- Pressurized Metal Bellows Shock Absorber for Space Applications.
- Creator
-
Trautwein, John, Kauffman, Jeffrey, Raghavan, Seetha, Putnam, Shawn, University of Central Florida
- Abstract / Description
-
Numerous spacecraft designs exist for exploring the surfaces of planetary bodies and each have their own advantages and disadvantages. All successful landings have been made by stationary landers or wheeled rovers that rely on one-time use mechanisms, such as crushable aluminum honeycomb shock absorbers or inflatable airbags, to reduce shock loading to the spacecraft during landing. The stationary lander is the simplest type of lander, but can only take data from one location. Wheeled rovers...
Show moreNumerous spacecraft designs exist for exploring the surfaces of planetary bodies and each have their own advantages and disadvantages. All successful landings have been made by stationary landers or wheeled rovers that rely on one-time use mechanisms, such as crushable aluminum honeycomb shock absorbers or inflatable airbags, to reduce shock loading to the spacecraft during landing. The stationary lander is the simplest type of lander, but can only take data from one location. Wheeled rovers add complexity in exchange for mobility to explore different locations. Rovers are limited by the terrain they can traverse; rovers becoming stuck have ended missions. In contrast to rovers and stationary landers, hoppers explore by making multiple launch and landing hops. They have the advantage of being able to avoid terrain that would cause a rover to become stuck. A hopper may require a landing shock absorber that can reliably operate multiple times in harsh environments.Most terrestrial shock absorbers use hydraulic fluid, allowing for compact and inexpensive devices. Hydraulics have been used in space applications, but require thermal controls to maintain the proper fluid viscosity. They also require dynamic seals which, in the case of a leak, can degrade performance, shorten mission life, and contaminate sensitive science equipment. Leakage is also a concern in pressurized systems in space because missions can take decades from when a system is installed to when it actually is used.To address these issues, a pressurized metal bellows shock absorber is proposed. This shock absorber could operate at nearly any expected spacecraft environment. Metal bellows are designed to operate from cryogenic temperatures to several hundred degrees Celsius. A hermetically sealed system eliminates the risks of a system with seals. Metal bellows are in common use for terrestrial harsh environments and vacuum applications. Small metal bellows are used as dampers for pressure control systems with small displacements.Models for the dynamics of this device are developed and presented here. Starting from the ideal gas law, polytropic compression, and compressible flow through an orifice, differential equations of motion and pressure are derived. These equations are nonlinear for the displacements under consideration and are nondimensionalized to help provide insight. Equations for static equilibrium, maximum initial displacement bounds, and estimated natural frequency are presented.Metal bellows can operate as a passive damper with a simple orifice between the control volumes. Optimization is performed for the nondimensional model of a passive damper. Because the response is highly nonlinear, a method is developed to estimate a damping coefficient that is used as the objective function for this optimization. Feasibility of this concept is investigated through an example design problem using data from a metal bellows manufacturer as constraints. An optimal mass configuration is found that meets the design constraints. Performance can be improved over the passive system by adding control. The first control strategy involves a check valve, such that the effective orifice size varies between compression and extension. The next control strategy replaces the orifice with a control valve. Varying the valve opening and closing timing can achieve optimal performance. Finally, using the metal bellows as an actuator to help launch the hopper is investigated. While the valve is closed, the gas in the second volume is compressed. Then the valve is opened the hopper is launched.The results of this research show that a metal bellows device holds promise as a landing shock absorber and launch actuator to extend the range of hopper spacecraft.
Show less - Date Issued
- 2015
- Identifier
- CFE0006015, ucf:51022
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006015
- Title
- Droplet impact on deep liquid pools: secondary droplets formation from Rayleigh jet break-up and crown splash.
- Creator
-
Castillo Orozco, Eduardo, Kumar, Ranganathan, Mansy, Hansen, Peles, Yoav, University of Central Florida
- Abstract / Description
-
This work aims to study the impact of a droplet on liquid pools of the same fluid to understand the formation of secondary drops from the central jet and crown splash that occur after the impact. The impact of droplets on a deep pool has applications in cleaning up oil spill, spray cooling, painting, inkjet printing and forensic analysis, relying on the changes in properties such as viscosity, interfacial tension and density. Despite the exhaustive research on different aspects of droplet...
Show moreThis work aims to study the impact of a droplet on liquid pools of the same fluid to understand the formation of secondary drops from the central jet and crown splash that occur after the impact. The impact of droplets on a deep pool has applications in cleaning up oil spill, spray cooling, painting, inkjet printing and forensic analysis, relying on the changes in properties such as viscosity, interfacial tension and density. Despite the exhaustive research on different aspects of droplet impact, it is not clear how liquid properties can affect the instabilities leading to the Rayleigh jet breakup and the number of secondary drops formed after it pinches off. In this work, through systematic experiments, the droplet impact phenomena is investigated by varying viscosity and surface tension of liquids as well as impact speeds. Further, using a Volume-of-Fluid (VOF) method, it is shown that Rayleigh-Plateau instability is influenced by these parameters, and capillary timescale is the appropriate scale to normalize the breakup time. Increase in impact velocity increases the height of the thin column of fluid that emerges from the liquid pool. Under certain fluid conditions, the dissipation of this extra kinetic energy along with the surface tension forces produces instabilities at the neck of the jet. This could result in jet breakup and formation of secondary drops. In other words, both the formation of the jet and its breakup require a balance between viscous, capillary and surface tension forces. Based on Ohnesorge number (Oh) and impact Weber number (We), a regime map for no breakup, Rayleigh jet breakup, and crown splash is suggested for 0.0033 ? Oh ? 0.136. For Weber numbers beyond the critical value and Oh ? 0.091 the jet breakup occurs (Rayleigh jet breakup regime). While for Oh (>) 0.091, the jet breakup is suppressed regardless of the Weber number. In addition, high impact velocity initiates the crown formation and if further intensified it can disintegrate it into numerous secondary drops (crown splash) and it is observed to occur at all Ohnesorge numbers and high enough Weber numbers, however, at high Oh, a large portion of kinetic energy is dissipated, thus Rayleigh jet breakup is suppressed regardless of the magnitude of the impact velocity. Moreover, a correlation is proposed for normalized time with respect to the normalized maximum height of jet.
Show less - Date Issued
- 2015
- Identifier
- CFE0006278, ucf:51593
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006278
- Title
- Quantifying the effects of boat wakes on intertidal oyster reefs in a shallow estuary.
- Creator
-
Campbell, Donna, Walters, Linda, Quintana-Ascencio, Pedro, Jachec, Steven, University of Central Florida
- Abstract / Description
-
There have long been concerns about the negative impacts of recreational boating activity in the Indian River Lagoon system (IRL), especially in Mosquito Lagoon (ML), the northernmost part of the IRL. My research is focused on the impacts of boat wakes on intertidal reefs formed by the eastern oyster, Crassostrea virginica. There has been a 24% loss of oyster habitat in ML since 1943, where natural oyster reefs have been replaced by dead oyster reefs which do not serve the same ecological...
Show moreThere have long been concerns about the negative impacts of recreational boating activity in the Indian River Lagoon system (IRL), especially in Mosquito Lagoon (ML), the northernmost part of the IRL. My research is focused on the impacts of boat wakes on intertidal reefs formed by the eastern oyster, Crassostrea virginica. There has been a 24% loss of oyster habitat in ML since 1943, where natural oyster reefs have been replaced by dead oyster reefs which do not serve the same ecological function. While there is anecdotal and correlative evidence that this loss is a result of boat wakes, no studies to date have confirmed dead reefs can be a direct result of boat wakes. Therefore, I addressed the following questions: (1) What wake heights are generated by a range of boat types, and (2) What amount of oyster movement and erosion occurs as a result of these boat wakes? A series of boat pass experiments addressed the first question; these results were utilized in experiments at Florida Institute of Technology's wave tank to observe sediment erosion and oyster movement as a result of specific wake heights. Model selection was used for both the field and wave tank experiments to determine which variables contributed most to explaining the wake heights, erosion, and oyster movement that occurred. Wake heights ranging from 0.05 cm to 20.80 cm were documented contacting the oyster reefs from the boat passes, with a mean of 2.95 cm. Boat type was less important than speed or distance when determining wake height. My wave tank results document that wake heights as small as 2 cm contacting oysters are capable of moving individual and clusters of oysters. Minimum distances for boats to travel in order to maintain wakes smaller than 2 cm at reefs are suggested for management purposes based on regression equations. This could minimize the amount of movement that occurs when oysters are subjected to boat wakes. The results of this study can help resource managers implement boating policies in Mosquito Lagoon, and contribute greatly to conserving this important ecosystem engineer.
Show less - Date Issued
- 2015
- Identifier
- CFE0005584, ucf:50242
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005584
- Title
- Characterization of Impact Damage and Fiber Reinforced Polymer Repair Systems for Metallic Utility Poles.
- Creator
-
Johnson, Cara, Mackie, Kevin, Tatari, Mehmet, Chopra, Manoj, University of Central Florida
- Abstract / Description
-
Previous studies have demonstrated that the behavior of ber reinforced polymers(FRPs) bonded to metallic utility poles are governed by the following failure modes; yieldingof the metallic substrate, FRP tensile rupture, FRP compressive buckling, and debonding ofFRP from the substrate. Therefore, an in situ method can be devised for the repair of utilitypoles, light poles, and mast arms that returns the poles to their original service strength.This thesis investigates the eect of damage due to...
Show morePrevious studies have demonstrated that the behavior of ber reinforced polymers(FRPs) bonded to metallic utility poles are governed by the following failure modes; yieldingof the metallic substrate, FRP tensile rupture, FRP compressive buckling, and debonding ofFRP from the substrate. Therefore, an in situ method can be devised for the repair of utilitypoles, light poles, and mast arms that returns the poles to their original service strength.This thesis investigates the eect of damage due to vehicular impact on metallic poles,and the eectiveness of externally-bonded FRP repair systems in restoring their capacity.Damage is simulated experimentally by rapid, localized load application to pole sections,creating dents ranging in depth from 5 to 45% of the outer diameter. Four FRP compositerepair systems were selected for characterization and investigation due to their mechani-cal properties, ability to balance the system failure modes, and installation eectiveness.Bending tests are conducted on dented utility poles, both unrepaired and repaired.Nonlinear nite element models of dented and repaired pole bending behavior aredeveloped in MSC.Marc. These models show good agreement with experimental results,and can be used to predict behavior of full-scale repair system. A relationship between dentdepth and reduced pole capacity is developed, and FRP repair system recommendations arepresented.
Show less - Date Issued
- 2013
- Identifier
- CFE0004697, ucf:49872
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004697
- Title
- Sustainability Assessment of a Municipal Utility Complex: a System of Systems Approach.
- Creator
-
Fahmy, Tarek, Oloufa, Amr, Tatari, Omer, Al-Deek, Haitham, Kincaid, John, University of Central Florida
- Abstract / Description
-
Construction of municipal utility complexes has to support continuing population growth, economic development, and a widespread of social interest in environmental preservation. Municipalities face challenges in designing, constructing, and operating environmentally sustainable utility complexes, and their primary goal in developing such a complex is to minimize the environmental impact resulting from energy production and waste treatment (both liquid and solid), management, and disposal....
Show moreConstruction of municipal utility complexes has to support continuing population growth, economic development, and a widespread of social interest in environmental preservation. Municipalities face challenges in designing, constructing, and operating environmentally sustainable utility complexes, and their primary goal in developing such a complex is to minimize the environmental impact resulting from energy production and waste treatment (both liquid and solid), management, and disposal. However, decision and policy makers lack a system of systems approach that takes into account multiple interdependent systems comprised of the functional system (infrastructure, facilities, operations within the complex), the economic system, the social/cultural system, and the environmental system (environmental impact on air, water, soil). This research proposes a decision support system (DSS) with a new methodology using Vensim software and system dynamics methodology to assess the sustainability of a municipal utility complex system. This DSS incorporates 1) multiple interdependent systems, 2) multiple sustainability/performance indices, and 3) composite sustainability index. Engineers, managers, and researchers should benefit from a system of systems perspective, and from the application of a sustainability assessment method that is developed to provide an environmentally-conscious design, construction and management. Although a municipal utility complex is built with synergistic opportunities for integration of processes of a wastewater treatment plant, a resource recovery facility (aka waste-to-energy (WTE) or incineration facility), a material recycling facility (MRF), and a landfill; engineers tend to use the traditional sustainability assessment methods only to assess the life cycle (LCA) of each system's process over time. They might not necessarily incorporate an assessment based on system dynamics of the functional, economic, environmental, and social/cultural systems. Data from a case study is utilized in this dissertation based on the municipal utility complex in Pasco County in the western region of the State of Florida, USA.
Show less - Date Issued
- 2015
- Identifier
- CFE0005944, ucf:50809
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005944
- Title
- EXPOSURE MATTERS: EXAMINING THE PHYSICAL AND PSYCHOLOGICAL HEALTH IMPACTS OF TOXIC CONTAMINATION USING GIS AND SURVEY DATA.
- Creator
-
Bevc, Christine A., Marshall, Brent K., University of Central Florida
- Abstract / Description
-
In the late 1970s and early 1980s, the grassroots environmental movement brought national attention to the issues related to inequities in environmental quality. Previous research addressing these environmental inequities has progressively increased and advanced methodologically. However, the arguments and focus have been primarily limited to examining the socio-demographics in an ongoing debate of race and class. This thesis extends past the methodological stalemate focusing on the...
Show moreIn the late 1970s and early 1980s, the grassroots environmental movement brought national attention to the issues related to inequities in environmental quality. Previous research addressing these environmental inequities has progressively increased and advanced methodologically. However, the arguments and focus have been primarily limited to examining the socio-demographics in an ongoing debate of race and class. This thesis extends past the methodological stalemate focusing on the application of Geographic Information Systems (GIS) using survey data in an environmental justice case study of a community in south Florida. This approach examines the social, health and environmental impacts of a Superfund site on a low income, minority community. Using geo-coded survey (N=223) and environmental data (ash deposition patterns), this thesis employs path analysis to test the hypothesis that "exposure matters." The "exposure matters" hypothesis suggests exposure (perceived, self-reported and actual) is a significant predictor of physical and psychological health. Results discuss significant findings, and then compare them with previous disaster and trauma-related research and present directions for future research.
Show less - Date Issued
- 2004
- Identifier
- CFE0000033, ucf:46081
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000033
- Title
- FRAMEWORKS FOR ENVIRONMENTAL POLICYMAKING IN BRAZIL AND CHILE: A COMPARATIVE POLICYMAKING ANALYSIS OF THE BELO MONTE AND HIDROAYS�N DAMS.
- Creator
-
Vogan, Robert J, Wilson, Bruce M., University of Central Florida
- Abstract / Description
-
A global proliferation of large dam construction since the 1950s has been accompanied by scientific research challenging the benefit of these projects while drawing attention to their numerous negative environmental and social impacts. The institutions that assess the costs and benefits associated with large dam proposals, creating policies either approving, altering, or disapproving them, collectively form what is known as a policymaking framework. Examining these frameworks allows observers...
Show moreA global proliferation of large dam construction since the 1950s has been accompanied by scientific research challenging the benefit of these projects while drawing attention to their numerous negative environmental and social impacts. The institutions that assess the costs and benefits associated with large dam proposals, creating policies either approving, altering, or disapproving them, collectively form what is known as a policymaking framework. Examining these frameworks allows observers to trace policies through outlined decision-making processes and can help to reveal inherent biases within those systems that may impact policy outcomes. Often, divergent policy outcomes, like the those observed in the cases of the Belo Monte dam in Brazil and HidroAys�n dam in Chile, are a result of variations in the environmental policymaking frameworks of the deviating cases. The subjects of this study present similar arrangements of costs and benefits but resulted incongruous policy outcomes, specifically that the HidroAys�n dam was not built while the Belo Monte dam is currently under construction. Existing bodies of literature outlining the environmental policymaking frameworks of Chile and Brazil fail to fully address the influence of external variables, including presidential influence, corruption, and electoral politics, on these cases. This project synthesizes an outline of the environmental policymaking frameworks of Chile and Brazil from existing literature and uses the divergent cases of the Belo Monte and HidroAys�n dams to provide evidence for the incorporation of these external variables to better understand the incongruous policy outcomes these frameworks produce.
Show less - Date Issued
- 2016
- Identifier
- CFH2000129, ucf:46011
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000129
- Title
- THE COST OF FEELING GOOD.
- Creator
-
Field, Casey M, Sturm, Ray, University of Central Florida
- Abstract / Description
-
The Cost of Feeling Good attempts to quantify the optimum portfolio returns of Socially Responsible Investment Funds and Dual-Purpose Portfolios. In order to meet the demands of investors who want to create a social impact and generate financial returns, investors can choose two methods. For the purpose of this study, the social returns were quantified and the financial returns were quantified using net present value. In every scenario, the socially responsible investment decision generated...
Show moreThe Cost of Feeling Good attempts to quantify the optimum portfolio returns of Socially Responsible Investment Funds and Dual-Purpose Portfolios. In order to meet the demands of investors who want to create a social impact and generate financial returns, investors can choose two methods. For the purpose of this study, the social returns were quantified and the financial returns were quantified using net present value. In every scenario, the socially responsible investment decision generated higher financial returns. Because of the immediate loss to an investor after choosing the DPP strategy, financially, the SRI fund appears to be the better approach for a financially driver investor. In terms of social returns, the DPP has a more clear impact on society. Measured as the charitable contribution given on an $1,000 investment, the socially responsible fund contributes far less to society on a per investor basis. Therefore, if an investor is interested in generating higher social returns and wants to be selective in terms of their charitable donation, they should choose the DPP model. In terms of tax brackets, investors in higher tax brackets have to generate higher financial returns on socially responsible investments in order to match the returns of a DPP. This is also true with investors who invest less in charity. Therefore, the investors that are in the highest tax bracket and contribute little to charity will need to generate far higher SRI returns according to the constructed theory. This finding is important to the growing millennial trend in sustainable investing.
Show less - Date Issued
- 2016
- Identifier
- CFH2000141, ucf:45940
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000141
