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- Title
- EFFECTS OF A MATHEMATICS CURRICULUM RICH IN SPATIAL REASONING ACTIVITIES ON FIFTH GRADE STUDENTS' ABILITIES TO SPATIALLY REASON: AN ACTION RESEARCH PROJECT.
- Creator
-
Varn, Theresa, Dixon, Juli, University of Central Florida
- Abstract / Description
-
ABSTRACT The purpose of this study is to describe the effect of a curriculum rich in spatial reasoning activities and experiences on the ability of my fifth grade students to spatially reason. The study was conducted to examine 1) the effects of my practice of incorporating spatial reasoning lessons and activities in my fifth-grade mathematics classroom on the students' ability to spatially reason and 2) the effects of my practice of incorporating spatial reasoning lessons and activities on...
Show moreABSTRACT The purpose of this study is to describe the effect of a curriculum rich in spatial reasoning activities and experiences on the ability of my fifth grade students to spatially reason. The study was conducted to examine 1) the effects of my practice of incorporating spatial reasoning lessons and activities in my fifth-grade mathematics classroom on the students' ability to spatially reason and 2) the effects of my practice of incorporating spatial reasoning lessons and activities on my students' ability to problem solve. Data were collected over a ten-week period through the use of student interviews, anecdotal records, photos of student work, student journals, pre- and posttests and a post-study survey. In this study, students demonstrated a statistically significant increase on all pre- and posttests. The student interviews, anecdotal records, photos of student work, and student journals all revealed spatial reasoning was used in mathematics problem solving. The study suggests that spatial reasoning can be taught and spatial reasoning skills can be used in problem solving.
Show less - Date Issued
- 2005
- Identifier
- CFE0000351, ucf:46295
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000351
- Title
- Effects of a Mathematics Graphic Organizer and Virtual Video Modeling on the Word Problem Solving Abilities of Students with Disabilities.
- Creator
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Delisio, Lauren, Dieker, Lisa, Vasquez, Eleazar, Hines, Rebecca, Dixon, Juli, University of Central Florida
- Abstract / Description
-
Over the last decade, the inclusion of students with disabilities (SWD) in the general education classroom has increased. Currently, 60% of SWD spend 80% or more of their school day in the general education classroom (U.S. Department of Education, 2013). This includes students with autism spectrum disorders (ASD), a developmental disability characterized by impairments in behavior, language, and social skills (American Psychological Association, 2013). Many of these SWD struggle with...
Show moreOver the last decade, the inclusion of students with disabilities (SWD) in the general education classroom has increased. Currently, 60% of SWD spend 80% or more of their school day in the general education classroom (U.S. Department of Education, 2013). This includes students with autism spectrum disorders (ASD), a developmental disability characterized by impairments in behavior, language, and social skills (American Psychological Association, 2013). Many of these SWD struggle with mathematics in the elementary grades; fewer than 20% of SWD are proficient in mathematics when they begin middle school, compared to 45% of their peers without disabilities. Furthermore, 83% of SWD are performing at the basic or below basic level in mathematics in the fourth grade (U.S. Department of Education, 2013). As the rate of ASD continues to increase (Centers for Disease Control, 2013), the number of students with this disability who are included in the general education classroom also continues to rise. These SWD and students with ASD are expected to meet the same rigorous mathematics standards as their peers without disabilities. This study was an attempt to address the unique needs of SWD and students with ASD by combining practices rooted in the literature, strategy instruction and video modeling.The purpose of this study was to determine the effects of an intervention on the ability of students with and without disabilities in inclusive fourth and fifth grade classrooms to solve word problems in mathematics. The intervention package was comprised of a graphic organizer, the K-N-W-S, video models of the researcher teaching the strategy to a student avatar from a virtual simulated classroom, TeachLivE, and daily word problems for students to practice the strategy. The researcher used a quasi-experimental group design with a treatment and a control group to determine the impact of the intervention. Students were assessed on their performance via a pretest and posttest. Analyses of data were conducted on individual test items to assess patterns in performance by mathematical word problem type.The effects of the intervention on SWD, students with ASD, and students without disabilities varied widely between groups as well as amongst individual students, indicating a need for further studies on the effects of mathematics strategy instruction on students with varying needs and abilities.
Show less - Date Issued
- 2015
- Identifier
- CFE0005782, ucf:50065
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005782
- Title
- Effects of a Mixed-Mode Instructional Program on the Communicative Turns of Preschoolers with Down syndrome who use Augmentative and Alternative Communication.
- Creator
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Nicsinger, Erika, Kent-Walsh, Jennifer, Schwartz, Jamie, Hahs-Vaughn, Debbie, Binger, Cathy, University of Central Florida
- Abstract / Description
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Children with Down syndrome are at increased risk for a variety of deficits, including those in the area of speech, language, and literacy. Speech-language pathologists (SLPs) have historically focused on building children's verbal and signed vocabulary, but these efforts do not always result in significant changes in children's functional communication. Augmentative and alternative communication (AAC) systems and interventions have been recommended by the American Speech-Language-Hearing...
Show moreChildren with Down syndrome are at increased risk for a variety of deficits, including those in the area of speech, language, and literacy. Speech-language pathologists (SLPs) have historically focused on building children's verbal and signed vocabulary, but these efforts do not always result in significant changes in children's functional communication. Augmentative and alternative communication (AAC) systems and interventions have been recommended by the American Speech-Language-Hearing Association as appropriate options for facilitating functional communication skills with children with Down syndrome ([American Speech-Language-Hearing Association [ASHA], 2010; New York State Department of Health [NYSDOH], 2006). In spite of these recommendations, there exists a critical shortage of SLPs who are clinically competent in providing necessary AAC services to children with Down syndrome (Edgar (&) Rosa-Lugo, 2007; Light, McNaughton, Drager, Roberts, (&) Wilson, 2004). As a result, families of children with varying disabilities, including Down syndrome report high levels of stress related to accessing important professional expertise and intervention for their children (Dabrowska (&) Pisula, 2010). Researchers and clinicians alike must consider alternative treatment delivery options that are responsive to the needs of families and children with complex communication needs (Cirrin et al., 2010; Light (&) McNaughton, 2015). A telepractice service delivery model has been documented to ease burdens felt by families when attempting to access rehabilitative services (Gladden, 2013). Telepractice involves the use of technology to connect clinicians and clients at a distance for the purposes of assessment, intervention, or consultation (Theodoros, 2011). An expanding body of research promotes the use of telepractice service delivery within AAC to address the needs of both children and families. One evidence-based AAC intervention of interest is communication partner instruction. Communication partner instruction, even in small doses, has been proven to be an effective method for providing parents and children with complex communication needs, specifically children with Down syndrome, access to necessary intervention (Kent-Walsh, Murza, Malani, (&) Binger, 2015). Partner instruction involves educating those critical stakeholders who surround the child most frequently (e.g., parents, educators, educational assistants) to recognize and respond to children's communicative signals and to create opportunities for children to participate in the conversation (Pennington, Goldbart, (&) Marshall, 2004). Despite the evidence supporting the use of communication partner instruction, SLPs continue to struggle with implementation in billable contexts (Ogletree, 2013). SLPs in the United States often operate in a billable context, where the client must be actively involved in the therapy session in order for practitioners to receive reimbursement from insurance companies for time spent with clients. This issue has served as a barrier to use of communication partner instruction, as currently accepted research-validated models use introductory parent sessions independent of the children's learning to teach partner skills. Therefore, the current investigation examined the effects of a communication partner instruction using a mixed-mode service delivery model, which incorporated face-to-face and telepractice sessions, as well as a billable context. The focus of the protocol was on educating parents in one aided language strategy using a communication partner instruction program incorporating continuous child involvement and a mixed-mode service-delivery model, including both face-to-face and telepractice intervention components (e.g., Skype/FaceTime), to address the need for interventions which consider stressors faced by families when attempting to access evidence-based AAC intervention. The study utilized a single-case, multiple-probe experimental design across three parent-child dyads. Baseline, intervention, generalization, and maintenance phases were used to investigate the efficacy of the nine-session intervention. Visual analysis and Improvement Rate Difference (IRD) analyses indicated that the intervention was highly effective in increasing parents' use of the target strategy and children's communicative turntaking during shared storybook reading. One-hundred percent of parent participants increased their performance from baseline to post-intervention (IRD = 1.0), and all parents maintained these levels of achievement during the maintenance phase (IRD = 1.0). Similarly, children increased their frequency of communicative turns from baseline to post-intervention (IRD = 1.0), and all children participants maintained these levels of turntaking during the maintenance phase (IRD = 1.0), as well as during a novel book series (IRD = 1.0). These findings suggest that the mixed-mode service delivery model, which includes both face-to-face and telepractice sessions, as well as continuous child involvement is an effective method for increasing parents' use of a target strategy and children's frequency of multimodal communicative turns. Clinical and professional implications, as well as future directions for research are discussed.
Show less - Date Issued
- 2016
- Identifier
- CFE0006542, ucf:51327
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006542
- Title
- EFFECTS OF A MODIFIED JUDO PROGRAM ON PSYCHOSOCIAL FACTORS IN TYPICALLY DEVELOPING AND CHILDREN WITH AUTISM SPECTRUM DISORDER: A MIXED-METHODS STUDY.
- Creator
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Tomey, Keanu L., Garcia, Jeanette M., Fukuda, David H., University of Central Florida
- Abstract / Description
-
PURPOSE: The purpose of this study was to examine the effect of a modified judo training program on psychosocial health in both typically developing (TD) and children with Autism Spectrum Disorder (ASD) using a mixed-methods approach. METHODS: The sample consisted of 5 children with ASD and 5 TD children (age=8-11yrs) who participated in 10 sessions of a modified judo program during their typical physical education time for school. Psychosocial factors (enjoyment, perceived competence,...
Show morePURPOSE: The purpose of this study was to examine the effect of a modified judo training program on psychosocial health in both typically developing (TD) and children with Autism Spectrum Disorder (ASD) using a mixed-methods approach. METHODS: The sample consisted of 5 children with ASD and 5 TD children (age=8-11yrs) who participated in 10 sessions of a modified judo program during their typical physical education time for school. Psychosocial factors (enjoyment, perceived competence, benefits of PA) were assessed at baseline and post intervention, with completion of all measures dependent upon the level of comfort expressed by the participant. At the end of the program, children took part in focus group discussions centered around their experience with the program, while key school staff participated in semi-structured interviews based on their observations of the program. All focus group discussions and interviews were audio-recorded and transcribed verbatim. RESULTS: Quantitative results for pre and post psychosocial measures showed no significant differences existed between PA self-efficacy (p=.99), PA enjoyment (p=.6), and barriers to PA (p=.27). Qualitative results revealed that the majority of the participants found the program to be enjoyable, with partner centered activities being particularly fun. Suggestions for improvement included increasing the duration and frequency of the judo classes. All children reported a desire to continue participating in the judo classes. Findings from staff interviews indicated that school staff observed improvements in psychosocial health and behavior both immediately following a judo class, and throughout the intervention period. Increased self-confidence was mentioned by all participating school staff members. CONCLUSION: Despite the lack of significant quantitative findings, psychosocial benefits were observed in both TD children and children with ASD, with all participants reporting their desire to continue with the program. Future studies should examine the psychosocial benefits in a judo-training program in larger sample of children over longer durations.
Show less - Date Issued
- 2017
- Identifier
- CFH2000252, ucf:46017
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000252
- Title
- EFFECTS OF A PLANT-BASED VEGAN DIET ON THE RISK OF CANCER: AN INTEGRATIVE REVIEW OF THE LITERATURE.
- Creator
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Silavent, Chelsie M, Bushy, Angeline, University of Central Florida
- Abstract / Description
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Cancer, an aggressive chronic disease, impacts the lives of millions of people every day. There are numerous proposed triggers related to the diagnosis and much remains to be learned about the causes. Associated with this disease's variability is the challenge to identify a single causative agent that lead to its prevention. Specific topics that need additional evidence relate to environmental factors and lifestyle behaviors in the development, treatment and, in some instances, even...
Show moreCancer, an aggressive chronic disease, impacts the lives of millions of people every day. There are numerous proposed triggers related to the diagnosis and much remains to be learned about the causes. Associated with this disease's variability is the challenge to identify a single causative agent that lead to its prevention. Specific topics that need additional evidence relate to environmental factors and lifestyle behaviors in the development, treatment and, in some instances, even suppression of disease progression. Specifically, a diet that excludes animal-based products but consists of a variety of fruits and vegetables (i.e., plant-based vegan diet) is reported to retard disease progression among some individuals diagnosed with cancer. The purpose of this thesis was to examine the effects of a plant-based vegan diet as a treatment approach with individuals who have been diagnosed with cancer. The methodology included a systematic review of literature focusing on use of a plant-based vegan diet on cancer risks in research articles published in peer reviewed journals from 2006 to 2018. Consistent findings include evidence that a diet high in fruits, vegetables, whole grains, and minimal amounts of animal products showed a decrease risk of the development of various types of cancer. Recommendations for nursing education, practice, policy and research are discussed.
Show less - Date Issued
- 2019
- Identifier
- CFH2000558, ucf:45619
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000558
- Title
- Effects of a Reading Inference Strategy Intervention on the Reading and Social Inference Abilities of Adults with Asperger Syndrome.
- Creator
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Murza, Kimberly, Nye, William, Ehren, Barbara, Schwartz, Jamie, Hahs-Vaughn, Debbie, University of Central Florida
- Abstract / Description
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The ability to generate inferences is a skill that is necessary to fully comprehend a text and understand the intentions, behaviors, and emotions of a conversational partner. Individuals with Asperger syndrome (AS) have been shown to demonstrate significant difficulty in inference generation in both social contexts and in reading comprehension. Although, the reciprocity of the four components of literacy (reading, writing, listening, and speaking) has been established in the literature ...
Show moreThe ability to generate inferences is a skill that is necessary to fully comprehend a text and understand the intentions, behaviors, and emotions of a conversational partner. Individuals with Asperger syndrome (AS) have been shown to demonstrate significant difficulty in inference generation in both social contexts and in reading comprehension. Although, the reciprocity of the four components of literacy (reading, writing, listening, and speaking) has been established in the literature (Bradley (&) Bryant, 1983; Catts (&) Kamhi, 2005; Englert (&) Thomas, 1987; Gillon (&) Dodd, 1995; Hiebert, 1980; Kroll, 1981; Ruddell (&) Ruddell, 1994); the relationship between inference generation in reading and social inference generation is not well understood. The present study investigated the efficacy of a language-focused reading inference strategy intervention (ACT (&) Check Strategy) on the general reading comprehension, inference generation in reading, social inference, and metacognitive ability of adults with AS. Twenty-five adults with AS were randomly assigned to either a treatment or a control group. The treatment group participants were divided into groups of 3-4 based on their availability and preferred location for treatment resulting in a total of 4 groups. Each group met in one-hour sessions twice a week for a total of six weeks. When controlling for pretest scores, the treatment group was found to perform significantly better on one measure of inference generation in reading and metacognitive ability compared to the control group. Significant differences between groups were not found in two measures of inference generation in reading comprehension or social inference ability. These findings suggest that the ACT (&) Check strategy was effective in improving participants' ability to generate inferences as they read and their metacognitive reading ability. However, instruction in inference generation in reading does not appear to generalize to other language modalities (i.e., social inference generation). This research provides support for an explicit language-focused strategy intervention addressing the reading inference deficit area. Further research is warranted to investigate potential interventions to address social inference skills for individuals with AS.
Show less - Date Issued
- 2011
- Identifier
- CFE0004146, ucf:49045
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004146
- Title
- Effects of a Reading Strategy with Digital Social Studies Texts for Eighth Grade Students.
- Creator
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Doan, Melissa, Ehren, Barbara, Little, Mary, Kent-Walsh, Jennifer, Hahs-Vaughn, Debbie, University of Central Florida
- Abstract / Description
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Recent data indicate that only 34% of American eighth grade students are able to demonstrate grade-level proficiency with academic reading tasks (NCES, 2011). The staggering nature of statistics such as this is even more profound when considering that high level literacy skills combined with mastery of digital texts have become practical requirements for success in secondary education, post-secondary education, and virtually all vocational contexts. Despite this incongruent scenario, little...
Show moreRecent data indicate that only 34% of American eighth grade students are able to demonstrate grade-level proficiency with academic reading tasks (NCES, 2011). The staggering nature of statistics such as this is even more profound when considering that high level literacy skills combined with mastery of digital texts have become practical requirements for success in secondary education, post-secondary education, and virtually all vocational contexts. Despite this incongruent scenario, little research has been conducted to evaluate instructional methods and reading comprehension strategies with digital texts.To address this critical issue, the present study examined the effects of a metacognitive reading comprehension instructional protocol (STRUCTURE Your Reading [SYR]; Ehren, 2008) with eighth grade students using digital texts in a standard social studies classroom in an urban American school setting. The focus of the protocol was on teaching strategies and self-questioning prompts before, during, and after reading. The study employed a randomized controlled design and consisted of three conditions with a total of 4 participating teachers and 124 participating students. The study was conducted over 25 instructional days and two instructional units with 13.83 treatment hours within the standard, social studies classes. Hierarchical ANCOVA analyses revealed that when controlling for pre-test measurements, the comparison and experimental groups performed significantly better than the control group with instructional unit test scores (Unit 2), reading strategy use in all stages of reading (before, during, and after), and self-questioning prompts during reading. Comparison and experimental groups did not significantly differ in these gains, indicating that this instructional protocol is effective with both paper and digital text. These findings suggest that the SYR instructional protocol is effective with secondary students in content area classrooms when using digital text. Furthermore, they suggest that metacognition and reading comprehension strategy instruction are able to be successfully embedded within a content area class and result in academic and metacognitive gains. Clinical implications and future research directions and are discussed.
Show less - Date Issued
- 2012
- Identifier
- CFE0004244, ucf:49537
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004244
- Title
- EFFECTS OF A SHORE PROTECTION PROJECT ON LOGGERHEAD AND GREEN TURTLE NESTING ACTIVITY AND REPRODUCTION IN BREVARD COUNTY, FLORIDA.
- Creator
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Brock, Kelly, Ehrhart, Llewellyn, University of Central Florida
- Abstract / Description
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Marine turtle reproductive success is strongly correlated with the stability and quality of the nesting environment. Because females show fidelity to key nesting beaches, the management and physical characteristics of these beaches directly affect future generations of marine turtles and may be essential for the recovery of these threatened and endangered species. The impacts of beach restoration on loggerhead turtles (Caretta caretta) and on green turtles (Chelonia mydas) were investigated....
Show moreMarine turtle reproductive success is strongly correlated with the stability and quality of the nesting environment. Because females show fidelity to key nesting beaches, the management and physical characteristics of these beaches directly affect future generations of marine turtles and may be essential for the recovery of these threatened and endangered species. The impacts of beach restoration on loggerhead turtles (Caretta caretta) and on green turtles (Chelonia mydas) were investigated. Previous studies concerning beach nourishment projects have focused on loggerhead turtles. I compared data between nourished and non-nourished areas and between loggerhead and green turtles. I found, at one season post-nourishment, negative effects on nesting success and no significant effect on reproductive success for both loggerheads and established the same relationships with green turtles. Physical attributes of the fill sand, which did not facilitate acute scarp formation or severe compaction, did not physically impede turtles in their attempts to nest. Instead, the decrease in nesting success was attributed to an absence of abiotic and or biotic factors that cue nesting behavior. The increase in loggerhead nesting success rates during the second season post-nourishment was attributed to the equilibration process of the seaward crest of the berm. After the beach was restored, both species of turtles placed nests significantly farther from the water in the nourished area than in the non-nourished area. Green turtles nested on or near the dune and loggerheads nested on the seaward crest of the berm. The tendency of loggerheads to nest closer to the water resulted in more loggerhead than green turtle nests being "washed out" by erosion during the equilibration process. There was a significant increase in hatching success only for loggerheads when wash outs were excluded, thus illustrating the importance of nest placement and the detrimental effects of the equilibration process to the reproductive success of loggerheads. A decrease in reproductive output occurred during the first season post-nourishment. The reduction in the estimated total number of hatchlings produced (reproductive output) was a consequence of decreased nesting success lowering nest numbers. This reduction demonstrates that, regardless of similar reproductive success rates, marine turtles incurred net losses during the first season following nourishment. These results further reveal the impacts of decreased nesting success and the importance of minimizing excessive non-nesting emergences associated with beach nourishment.
Show less - Date Issued
- 2005
- Identifier
- CFE0000493, ucf:46365
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000493
- Title
- EFFECTS OF A TREATMENT USING COMPUTER GENERATION OF ISOMETRIC AND ORTHOGRAPHIC PROJECTIONS ON MIDDLE SCHOOL STUDENTSÂÂ' SPATIAL ABILITY.
- Creator
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Traas, Adam, Haciomeroglu, Erhan, University of Central Florida
- Abstract / Description
-
The primary focus of this study examines the effectiveness of the CRIOSAT (Computerized Rotational Isometric and Orthographic Spatial) spatial ability treatment on a random sample of middle school studentsÂÂ' (n=137) spatial ability as measured by the Purdue Spatial Visualization Test: Rotations Test (PSVT-ROT) (Guay, 1977). The secondary focus of this study investigates the relationships between mathematical achievement, problem solving preferences, and spatial ability...
Show moreThe primary focus of this study examines the effectiveness of the CRIOSAT (Computerized Rotational Isometric and Orthographic Spatial) spatial ability treatment on a random sample of middle school studentsÂÂ' (n=137) spatial ability as measured by the Purdue Spatial Visualization Test: Rotations Test (PSVT-ROT) (Guay, 1977). The secondary focus of this study investigates the relationships between mathematical achievement, problem solving preferences, and spatial ability. The secondary focus was tested on a subsample (n=41), with the problem solving preferences measured via the Mathematical Processing Instrument (MPI) (Suwarsono, 1982). Findings indicated no significant gains in spatial ability scores after studentsÂÂ' use of the CRIOSAT treatment; while some increases in spatial ability took place in males. Significant positive correlation was identified between mathematics achievement and spatial ability; while conversely, a significant negative correlation was found between mathematics achievement and level of visual problem solving used by students.
Show less - Date Issued
- 2010
- Identifier
- CFE0003033, ucf:48345
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003033
- Title
- EFFECTS OF ABORTION ON COLLEGE WOMEN'S MENTAL HEALTH.
- Creator
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Bologna, Estefany, Fouty, Homer Edward, University of Central Florida
- Abstract / Description
-
Since the legalization of abortion, some research studies have argued that abortion has a neutral effect when considering other coexistent factors (e.g. Adler et al., 1990; Major et al., 2000; Steinberg & Russo, 2008). Other studies have concluded that abortion has a negative influence on women's psyche (e.g. Congleton & Calhoun, 1993; Cougle, Reardon, & Coleman, 2005; Hamana et al., 2010). College populations have been generally excluded from abortion research, even though, in 2007, 57% of...
Show moreSince the legalization of abortion, some research studies have argued that abortion has a neutral effect when considering other coexistent factors (e.g. Adler et al., 1990; Major et al., 2000; Steinberg & Russo, 2008). Other studies have concluded that abortion has a negative influence on women's psyche (e.g. Congleton & Calhoun, 1993; Cougle, Reardon, & Coleman, 2005; Hamana et al., 2010). College populations have been generally excluded from abortion research, even though, in 2007, 57% of women obtaining abortions were between the ages of 20 and 30 years (U.S. Census Bureau, 2012). This study intended to measure the influence of induced abortion on the current mental health status of college women and describe the characteristics of women obtaining abortions. An online survey was administered to female college students (N= 46). The participants were divided into two pregnancy outcome groups: (1) women who reported a history of fetal deliveries, and (2) women who reported a history of abortion. Each group was asked if abortion or fetal delivery contributed to their current mental health status. Independent variables included the participants' pregnancy outcome (abortion vs. delivery) and establishing if abortion/fetal delivery contributed to current mental health (yes/no answer). The dependent variables included current psychological distress symptoms as measured by the nine primary symptom dimensions of the Symptom Checklist-90-Revised. The data were analyzed using a two-way mixed-design MANOVA. Evidence indicated that psychological symptoms were not dependent on respondents' perception of whether or not current mental health was affected by pregnancy outcome. This study does not support public policies or practice based on the belief that abortion emotionally harms women. Further research should concentrate in strategies to prevent unwanted pregnancy in order to reduce the need for abortion.
Show less - Date Issued
- 2013
- Identifier
- CFH0004421, ucf:45101
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004421
- Title
- EFFECTS OF ADVANCE ORGANIZERS ON LEARNING AND RETENTION FROM A FULLY WEB-BASED CLASS.
- Creator
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Chen, Baiyun, Hirumi, Atsusi, University of Central Florida
- Abstract / Description
-
The purpose of this study is to investigate the short-term and long-term effects of two kinds of advance organizers (AOs), a visual concept map and a text outline. The AOs were administered in a fully Web-based course in health care ethics. The outcome measures are students' knowledge acquisition and application in two posttests. This study was conducted through a post-test only control group design with a random assignment. The population of the study involved 166 college students who...
Show moreThe purpose of this study is to investigate the short-term and long-term effects of two kinds of advance organizers (AOs), a visual concept map and a text outline. The AOs were administered in a fully Web-based course in health care ethics. The outcome measures are students' knowledge acquisition and application in two posttests. This study was conducted through a post-test only control group design with a random assignment. The population of the study involved 166 college students who participated in this online class in their junior or senior year. The voluntary research participants were randomly assigned into the two treatment groups and one control group. The treatment of AO was administered as an integral part of a one-week-long online module on the topic of patient-physician relationships. Students of the two treatment groups were presented with one of the two AOs, while the control group was instructed to proceed to textbook reading without an AO. Then, students were tested on the subject matter with two parallel posttests. Both posttests were composed of a multiple-choice question quiz and a set of scenario-based essay questions. The students took posttest I at the end of the instructional week, and posttest II four weeks after. A survey and interviews were also conducted to supplement the quantitative results with contextual information. The findings do not demonstrate a statistically significant AO effect among the treatment groups and the control group. However, in agreement with the previous research, this study shows a positive but inconclusive benefit of using AOs for students' short-term knowledge acquisition. The students using a concept map consistently obtained higher learning achievements than individuals using a text outline. More importantly, this study reiterated the proposition that students of lower-learning abilities benefit more from using an AO for online learning than those of higher-learning abilities. The current study extends our knowledge on the use of AOs in fully Web-based educational environments. The results indicated that although AOs more often than not have small facilitative effects for learners, they are not equally effective for all learners in all learning situations. The incorporation of the instructional strategies, such as AOs, in Web-based courses and programs might benefit online learners, especially those students of lower verbal and analytical abilities, or of lower prior knowledge of the material-to-be-learned.
Show less - Date Issued
- 2007
- Identifier
- CFE0001556, ucf:47137
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001556
- Title
- Effects of Allotropic Transformations on Interdiffusion Behavior in Binary Systems.
- Creator
-
Ewh, Ashley, Sohn, Yongho, Suryanarayana, Challapalli, Coffey, Kevin, University of Central Florida
- Abstract / Description
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Diffusion plays a significant role in most materials systems by controlling microstructural development. Consequently, the overall properties of a material can be largely dependent upon diffusion. This study investigated the interdiffusion behavior of three binary systems, namely, Mo-Zr, Fe-Mo, and Fe-Zr. The main interest in these particular metals is for application in nuclear fuel assemblies. Nuclear fuel plates generally consist of two main components which are the fuel and the cladding....
Show moreDiffusion plays a significant role in most materials systems by controlling microstructural development. Consequently, the overall properties of a material can be largely dependent upon diffusion. This study investigated the interdiffusion behavior of three binary systems, namely, Mo-Zr, Fe-Mo, and Fe-Zr. The main interest in these particular metals is for application in nuclear fuel assemblies. Nuclear fuel plates generally consist of two main components which are the fuel and the cladding. Due to diffusional interactions that can occur between these two components, a third is sometimes added between the fuel and cladding to serve as a diffusion barrier layer. Fe, Mo, and Zr can act as either cladding or barrier layer constituents and both Mo and Zr also serve as alloying additions in uranium based metallic fuels. Therefore, a fundamental understanding of the diffusional interactions in these systems is critical in predicting the performance and lifetime of these fuels. In order to study this diffusion behavior, a series of solid-to-solid diffusion couples were assembled between Fe, Mo, and Zr. These couples were then diffusion annealed isothermally for various predetermined times over a range of temperatures, including some both above and below the allotropic transformation temperatures for Fe and Zr. Following the diffusion anneal, the couples were water quenched, cross-sectioned, and prepared for microstructural and compositional characterization. A combination of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and electron probe microanalysis (EPMA) were used to obtain micrographs showing the microstructure and to collect compositional data for identifying intermediate phases and determining concentration profiles across the interdiffusion zone.Based on this characterization, the phases that developed in the diffusion zones were identified. In the Mo-Zr system, a large Zr solid solution layer developed in the couples annealed at and above 850(&)deg;C and a thin (~1-2 ?m) layer of Mo2Zr formed in all couples. Growth constants and concentration dependent interdiffusion coefficients were calculated for the Mo2Zr and Zr solid solution phases, respectively. In the Fe-Mo system, both the ?-Fe2Mo and ?-Fe7Mo6 phases were observed in couples annealed at 900(&)deg;C and below while ?-Fe7Mo6 and ?-Fe solid solution layers were observed in couples annealed above 900(&)deg;C. The relevant growth constants and activation energies for growth were calculated. In the Fe-Zr system, the couple annealed at 750(&)deg;C developed an FeZr2 and an FeZr3 layer while the couple annealed at 850(&)deg;C developed an Fe2Zr and Fe23Zr6 layer in the diffusion zone. The results of this analysis were then compared to available information from literature and the corresponding binary phase diagrams for each system. The results are discussed with respect to the effects of the allotropic transformations of Fe and Zr on the interdiffusion behavior in these systems.
Show less - Date Issued
- 2012
- Identifier
- CFE0004374, ucf:49422
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004374
- Title
- Effects of American foreign policy.
- Creator
-
Lamont, Corliss
- Date Issued
- 1952
- Identifier
- 363258, CFDT363258, ucf:5283
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/FCLA/DT/363258
- Title
- Effects of an Acute High-Volume Isokinetic Intervention on Circulating Levels of TNF-? and STNFR: Influence of Age.
- Creator
-
Arroyo Delgado, Eliott, Wells, Adam, Hoffman, Jay, Stout, Jeffrey, Fukuda, David, University of Central Florida
- Abstract / Description
-
The immune system has been implicated in recovery and muscle regeneration following exercise. In response to muscle damage, the immune system responds with an increase in circulating pro-inflammatory cytokines with the goal of recruiting leukocytes to the damaged area. Tumor Necrosis Factor-alpha (TNF-?), in particular, has been shown to be implicated in both muscle regeneration and muscle wasting. However, it remains unclear whether TNF-? is responsible for the age-related losses in muscle...
Show moreThe immune system has been implicated in recovery and muscle regeneration following exercise. In response to muscle damage, the immune system responds with an increase in circulating pro-inflammatory cytokines with the goal of recruiting leukocytes to the damaged area. Tumor Necrosis Factor-alpha (TNF-?), in particular, has been shown to be implicated in both muscle regeneration and muscle wasting. However, it remains unclear whether TNF-? is responsible for the age-related losses in muscle size and function. Also, due to the high clearance rate of TNF-? from circulation, analyzing the circulating levels of soluble TNF-? receptors 1 and 2 (STNFR1 and STNFR2) may provide a better indication of inflammatory events. Therefore, the purpose of this study was to compare changes in circulating levels of TNF-?, STNFR1, and STNFR2 following an acute muscle damaging intervention in young age (YA) and middle-aged (MA) males. Recreationally active young (YA; N=9, 21.8 (&)#177; 2.2 y, 179.5 (&)#177; 4.9 cm, 91.2 (&)#177; 12.2 kg, 21.8 (&)#177; 4.3% BF) and middle-aged (MA; N=10, 47.0 (&)#177; 4.4 y, 176.8 (&)#177; 7.6 cm; 96.0 (&)#177; 21.5 kg, 25.4 (&)#177; 5.3% BF) males completed an acute muscle damaging protocol (MDP). Blood samples were obtained at baseline (BL), immediately (IP), 30 minutes (30P), 60 minutes (60P), 120 minutes (120P), 24 hours (24H), and 48 hours (48H) post-MDP. Lower body performance was analyzed via isokinetic dynamometer at BL, IP, 120P, 24H, and 48H. No significant group x time interactions or main group effects were observed for TNF-?, STNFR1, STNFR2 or any marker of muscle damage. When collapsed across groups, plasma lactate was significantly elevated at IP (p (<) 0.001) and 30P (p = 0.003); serum myoglobin was increased at 30P (p = 0.002), 60P (p = 0.001), and 120P (p = 0.007); creatine kinase was elevated at 24H (p = 0.001) and 48H (p = 0.005). Plasma concentrations of TNF-? were unchanged following MDP. With both groups combined, serum STNFR1 was decreased at 30P (p = 0.001) and increased at 48H (p = 0.028). Serum STNFR2 was decreased at 30P (p = 0.008), 60P (p = 0.003), and 120P (p = 0.002). The results of this study indicate that the TNF-? and STNFRs response to exercise is similar between young and middle-aged males. Measuring STNFRs may be a more appropriate method of assessing the acute inflammatory response to muscle damage. In addition, an acute bout of exercise may attenuate ectodomain shedding of TNFR1 and TNFR2.
Show less - Date Issued
- 2017
- Identifier
- CFE0006561, ucf:51350
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006561
- Title
- Effects of an Acute High-Volume Isokinetic Intervention on Inflammatory and Strength Changes: Influence of Age.
- Creator
-
Gordon, Joseph, Hoffman, Jay, Stout, Jeffrey, Fukuda, David, University of Central Florida
- Abstract / Description
-
PURPOSE: The purpose of this study was to compare the effects of a high volume isokinetic intervention on lower body strength and inflammation, as well as markers of muscle damage in the subsequent 48 hours between younger and middle-aged men. METHODS: 19 healthy, recreationally trained men were randomly assigned to two groups, younger adults (YA: 21.8 (&)#177; 2.0 y; 90.7 (&)#177; 11.6 kg; 21.5 (&)#177; 4.1 % body fat), or middle-aged adults (MA: 47.0 (&)#177; 4.4 y; 96.0 (&)#177; 21.5; 24.8...
Show morePURPOSE: The purpose of this study was to compare the effects of a high volume isokinetic intervention on lower body strength and inflammation, as well as markers of muscle damage in the subsequent 48 hours between younger and middle-aged men. METHODS: 19 healthy, recreationally trained men were randomly assigned to two groups, younger adults (YA: 21.8 (&)#177; 2.0 y; 90.7 (&)#177; 11.6 kg; 21.5 (&)#177; 4.1 % body fat), or middle-aged adults (MA: 47.0 (&)#177; 4.4 y; 96.0 (&)#177; 21.5; 24.8 (&)#177; 6.3 % body fat). Both groups reported to the human performance laboratory (HPL) on four separate occasions. On the first visit (D1), anthropometric assessment, as well as a familiarization session with the isokinetic dynamometer, was performed. A muscle damaging protocol (HVP) was performed on the second visit (D2) consisting of 8 sets of 10 repetitions at 60(&)deg;(&)#183;sec-1 on the isokinetic dynamometer. An assessment protocol (AP) was performed to assess performance decrements between the YA and MA groups. For this protocol, a maximal voluntary isometric contraction (MVIC) was performed, as well as 3 isokinetic kicks at 2 different speeds (240(&)deg;(&)#183;sec-1 and 60(&)deg;(&)#183;sec-1). For the MVIC, values for peak torque (PKT), average torque (AVGT), rate of torque development at 100 ms (RTD100), and 200 ms (RTD200) were recorded. For the isokinetic kicks at 240(&)deg;(&)#183;sec-1 (ISK240) and 60(&)deg;(&)#183;sec-1 (ISK60), values were also recorded for peak torque (PKT), average torque (AVGT), as well as peak power (PP), and average power (AVGP). The AP was performed before the HVP (BL), immediately after the HVP (IP), 120 minutes after the HVP (120P), as well as one (24H) and two (48H) days following the HVP. Blood draws were also taken at BL, IP, 24H, and 48H, as well as 30 minutes (30P), and 60 minutes (60P) following the HVP to assess circulating levels of creatine kinase (CK), myoglobin (Mb), c-reactive protein (CRP), and interleukin 6 (IL-6). Ultrasound assessment was also performed at BL and IP as well to assess changes in muscle morphology as a result of the intervention. Performance, blood, and ultrasound markers were analyzed using a repeated measures ANOVA to observe between group comparisons for all of the outcome variables. RESULTS: There were no group differences observed for isometric or isokinetic peak torque or average torque, nor were there differences in isokinetic peak power or average power between the two groups as a result of the intervention. There were, however, differences in the pattern for rate of torque development at 100 ms and 200 ms between the two groups. RTD 100 was decreased at IP and 48H in YA, with MA showing decreases at IP, but also 120P and 24H unlike YA. RTD200 was decreased at all time points in YA, while MA was decreased at IP, 24H, and 48H, but not 120P. For markers of muscle damage and inflammation, there were no differences in the response of Mb, CK, CRP, or IL-6 between groups. CONCLUSIONS: Age does not appear to be a driving factor in the inflammatory or muscle damage response from a high volume isokinetic intervention. Though changes in peak torque and average torque from a high volume isokinetic intervention do not seem to differ between younger and middle-aged adults, the rate of torque production at 100ms and 200ms is different between groups. This suggests that while recovery to average or maximal strength after an exercise bout may not be affected greatly by age, the rate of neuromuscular recovery from exercise may be primarily affected by other factors such as training status.
Show less - Date Issued
- 2017
- Identifier
- CFE0006594, ucf:51259
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006594
- Title
- EFFECTS OF AN EVIDENCE-BASED INTERVENTION ON STRESS AND COPING OF FAMILIES OF CRITICALLY ILL TRAUMA PATIENTS.
- Creator
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Knapp, Sandra, Sole, Mary Lou, University of Central Florida
- Abstract / Description
-
Problem/Purpose: Critical care nurses are frequently exposed to the stress experienced by their patients' families, yet they often do not have the knowledge or skills to help family members cope with the stress of critical illness. While needs and stressors of families of the critically ill have been researched extensively, no prior studies have been conducted to determine the effects of an evidence-based nursing intervention for reducing family members' stress and improving their coping...
Show moreProblem/Purpose: Critical care nurses are frequently exposed to the stress experienced by their patients' families, yet they often do not have the knowledge or skills to help family members cope with the stress of critical illness. While needs and stressors of families of the critically ill have been researched extensively, no prior studies have been conducted to determine the effects of an evidence-based nursing intervention for reducing family members' stress and improving their coping skills. The purpose of this study was to determine if an evidence-based nursing intervention designed to address the needs of family members would reduce stress and improve coping skills in family members of critically ill trauma patients. Additionally, the study assessed the family members' perceptions of how well their needs were met while their loved one was hospitalized in the surgical intensive care unit (SICU). Methods: Using a quasi-experimental, nonequivalent control group design, an evidence-based intervention for critical care nurses was implemented to test its effect on stress and coping of family members of critically ill trauma patients. The study setting was the SICU at a tertiary university hospital in north central Florida. Subjects were family members of critically ill trauma patients who had been hospitalized in the SICU for at least 48 hours. Participants in the control group were given a packet containing instruments that measured 1) anxiety as an indicator of stress (Spielberger's State-Trait Anxiety Inventory ); 2) coping (Lazarus and Folkman's Ways of Coping Questionnaire ); and 3) assessment of family members' perception of having their needs met while their family member was in the SICU (Family Care Survey ). An evidence-based family bundle was implemented over an eight-week period and included an educational program for the nurses. After eight weeks, participants in the experimental group were given the same instruments previously administered to the control group. Anxiety levels, coping skills, and family members' perception of having needs met were compared between the two groups to determine the effectiveness of the evidence-based intervention. Results: A total of 84 family members participated in the study (control = 39; experimental = 45). The majority were women (n=60), spouse or parent of the patient (n=47), and Caucasian (n=70). Mean ages were 45.9 years for the control group and 47.4 years for the experimental group. No differences were noted in the demographic characteristics between the control and experimental groups. Using an independent samples t-test, no significant differences (p > .05) were noted between groups for either state or trait anxiety, although the mean anxiety score was lower in the experimental group. Significant differences between groups were noted on two of the eight coping subscales: Distancing and Accepting Responsibility. Improved coping, although not statistically significant, was noted on four additional subscales: Confrontive Coping, Self-Controlling, Planful Problem-Solving, and Positive Reappraisal. Overall coping scores also improved, but not statistically, for the total Ways of Coping Scale (both 50 and 66 item totals). Although not statistically significant, participants in the experimental group rated four out of eight items higher on the FCS, indicating an increased perception that more of their needs were met, greater overall satisfaction with the care that family members received, increased nurses' consideration of family members' needs and the inclusion of those needs in planning nursing care, and greater encouragement for family members to participate in care. Although findings were not statistically significant, the trend implies increased satisfaction with family care in areas involving family care and family member needs, including needs in planning care and encouragement to participate in care. In areas regarding information and communication, there was overall less satisfaction in both groups. Conclusions: This study provides data that can be used as a guide in developing programs that help families function and adapt to the extremely stressful experience of having a loved one who is critically ill. The information can be used to develop future research on larger scales with a longer and more extensive plan for implementation of the intervention to assist in a unit culture change. Nurses can use the results to facilitate practice changes in caring for families of critically ill patients. Modifying the interventions to focus on an interdisciplinary approach to meet families' needs, reduce stress, and improve coping also warrants further development and testing. Funding acknowledgement: Florida Nurses Foundation and the American Association of Critical Care Nurses. College of Nursing, University of Central Florida
Show less - Date Issued
- 2009
- Identifier
- CFE0002774, ucf:48134
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002774
- Title
- EFFECTS OF ANIMAL ASSISTED THERAPY ON HUMAN HEALTH.
- Creator
-
Swanson, Gene, Bushy, Angeline, University of Central Florida
- Abstract / Description
-
The purpose of this thesis is to conduct an integrative review of existing literature focusing on Animal Assisted Therapy (AAT), specifically canines, on human health. The reviewed articles were published between the years of 2000 to 2014, written in the English language, scholarly in nature, in peer-reviewed journals with access to full text electronic versions of the article, along with articles that provided current anecdotal information related to the effects of AAT. Search terms included...
Show moreThe purpose of this thesis is to conduct an integrative review of existing literature focusing on Animal Assisted Therapy (AAT), specifically canines, on human health. The reviewed articles were published between the years of 2000 to 2014, written in the English language, scholarly in nature, in peer-reviewed journals with access to full text electronic versions of the article, along with articles that provided current anecdotal information related to the effects of AAT. Search terms included the phrase, "animal assisted therapy" in the title. Results of the literature search yielded an enormous quantity of recent and innovative research on various aspects of AAT. Various animals were identified with ATT, most often canines; however, it is not uncommon to find that horses, dolphins, felines, birds, or even small mammals satisfying the same roles. Of these, for this thesis thirteen research articles were selected that dealt primarily with canines in AAT. The findings from the review for this thesis suggested that despite the large volume of available research on ATT in general, a gap in literature exists focusing on the health outcomes with specific animal species. Additionally, the research was noted to be fragmented in nature and the findings were inconsistent; thus, limiting the development of evidence based ATT interventions. Implications for nursing research, policy, education and practice are discussed, along with limitations of this integrative review.
Show less - Date Issued
- 2014
- Identifier
- CFH0004672, ucf:45262
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004672
- Title
- EFFECTS OF ATMOSPHERIC TURBULENCE ON THE PROPAGATION OF FLATTENED GAUSSIAN OPTICAL BEAMS.
- Creator
-
Cowan, Doris, Andrews, Larry, University of Central Florida
- Abstract / Description
-
In an attempt to mitigate the effects of the atmosphere on the coherence of an optical (laser) beam, interest has recently been shown in changing the beam shape to determine if a different power distribution at the transmitter will reduce the effects of the random fluctuations in the refractive index. Here, a model is developed for the field of a flattened Gaussian beam as it propagates through atmospheric turbulence, and the resulting effects upon the scintillation of the beam and upon beam...
Show moreIn an attempt to mitigate the effects of the atmosphere on the coherence of an optical (laser) beam, interest has recently been shown in changing the beam shape to determine if a different power distribution at the transmitter will reduce the effects of the random fluctuations in the refractive index. Here, a model is developed for the field of a flattened Gaussian beam as it propagates through atmospheric turbulence, and the resulting effects upon the scintillation of the beam and upon beam wander are determined. A comparison of these results is made with the like effects on a standard TEM00 Gaussian beam. The theoretical results are verified by comparison with a computer simulation model for the flattened Gaussian beam. Further, a determination of the probability of fade and of mean fade time under weak fluctuation conditions is determined using the widely accepted lognormal model. Although this model has been shown to be somewhat optimistic when compared to results obtained in field tests, it has value here in allowing us to compare the effects of atmospheric conditions on the fade statistics of the FGB with those of the lowest order Gaussian beam. The effective spot size of the beam, as it compares to the spot size of the lowest order Gaussian beam, is also analyzed using Carter's definition of spot size for higher order Gaussian beams.
Show less - Date Issued
- 2006
- Identifier
- CFE0001377, ucf:46969
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001377
- Title
- Effects of avian breeding colonies on a man-made freshwater marsh in East Central Florida.
- Creator
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Burney, James L., Stout, I.J., Arts and Sciences
- Abstract / Description
-
University of Central Florida College of Arts and Sciences Thesis; The effects of nutrient loading from avian breeding colonies into aquatic/marine ecosystems have been well documented. Documented influences include increased productivity of aquatic/marine macrophytes, elevated sediment nutrient concentrations, and increased densities of zooplankton and planktivorus fishes. The primary pathway of nutrient export from the rookery is through excreta from adult birds and their offspring. This...
Show moreUniversity of Central Florida College of Arts and Sciences Thesis; The effects of nutrient loading from avian breeding colonies into aquatic/marine ecosystems have been well documented. Documented influences include increased productivity of aquatic/marine macrophytes, elevated sediment nutrient concentrations, and increased densities of zooplankton and planktivorus fishes. The primary pathway of nutrient export from the rookery is through excreta from adult birds and their offspring. This study examined the influences of a 400-nesting pair rookery of cattle egret (Bubulcus ibis) in 1990 and a 75-nesting pair rookery of cattle egret in 1991 on a man-made freshwater treatment marsh in east central Florida. Because the fundamental intent of the created marsh (study site) was the removal of nutrients, primarily nitrogen and phosphorus, from advanced treated wastewater prior to discharge into public surface waters, the main objective of this study was to document the effects of the avian breeding colonies on water quality within the system. Secondary objectives of the study were to document influences on phytoplankton density and aquatic faunal community structure, as well as to estimate spatial and temporal limits of rookery influences. The results indicated significant water quality differences between rookery and reference sites during 1990 and 1991. The results also indicated significant differences between phytoplankton productivity and aquatic macroinvertebrate community structure between rookery and reference sites during 1990 and 1991. The effects of nutrient loading from the rookeries were confined to within 150 m and background water quality conditions were regained within one month of rookery abandonment. In effect, the 1990 and 1991 rookery sites were characterized as limited, transient "islands" of increased eutrophication within the marsh.
Show less - Date Issued
- 1995
- Identifier
- CFR0011941, ucf:53110
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0011941
- Title
- EFFECTS OF BEDDING VOID ON INTERNAL MOMENT INCREASE IN CONCRETE PIPES.
- Creator
-
Kazma, Jad, Kuo, Shiou-San, University of Central Florida
- Abstract / Description
-
Large diameter concrete pipes have been used in many areas of central Florida to carry pressured sewage flow. These pipes have been typically located at six feet below finished roadway elevation, and ranges in diameter from thirty six to sixty inches. The water table is typically located at shallow depth below finished roadway elevation, and generally fluctuates between five to ten feet depending on the relative roadway elevation to mean sea level. These pipes are under pressure when carrying...
Show moreLarge diameter concrete pipes have been used in many areas of central Florida to carry pressured sewage flow. These pipes have been typically located at six feet below finished roadway elevation, and ranges in diameter from thirty six to sixty inches. The water table is typically located at shallow depth below finished roadway elevation, and generally fluctuates between five to ten feet depending on the relative roadway elevation to mean sea level. These pipes are under pressure when carrying the sewage flow, but return to normal atmospheric pressures when the flow stops. Since the water table encases most of the pipe circumference, no leaks is developed from the water table to the pipe when the pipe is under pressure. Once the pressure in the pipes returns to zero, the water starts seeping into the pipe while washing the subgrade with it into the pipe's interior. The subgrade washes into the pipe at the joint inverts between adjacent pieces of the pipe, since the invert is where the most tension exists in the joint under the weight of the soil and traffic loading above the pipe, making it the most probable location where a gap in the joint would form. This would cause the origination of a small void under the pipe, which creates pressure redistribution in the subgrade reaction under the pipe. As the void develops in the middle third of the bedding under the invert, pressure redistribution occurs to the outer two thirds of the bedding. As the stress increases in the outer portions of the bedding, more subgrade material is washed into the pipe when it is not under pressure, making the void larger. As the void becomes large, the moment in the pipe is greatly increased, and therefore the gap in the joint is increased due to the tension increase at the bottom of the pipe. More material is allowed into the pipe, and the void becomes deeper as fewer restrictions are encountered between the water table and the empty pipe. As the pipe becomes pressurized, more subgrade material is disturbed by the leak from the inside of the pipe to the outside, and void is constantly generated. The void then leads to the continuous settlement of the roadway. It is intended by this study to model the stresses in the subgrade around the pipe using a finite element software to determine the effects of void in the pipe's bedding on the stress around the pipe's outer perimeter. The stresses calculated as a result of the void will then be used in determining the increase in internal moment created in the pipe as the void is generated and became larger and deeper. Average stresses on the top and bottom of the pipe were calculated due to the soil profile dead load and live load caused by loading the soil profile with one and two HS-20 trucks. The average stresses were recalculated after the addition of void in the pipe bedding. The void width and depth were varied to come up with the case that would generate the highest unbalanced load on the pipe. The average bottom stress was subtracted from the average top stress to determine the unbalanced load on the pipe that would cause an internal moment in the pipe. At the most critical case, a forty kilo pounds per foot moment was caused by the existence of the void under the sixty inch diameter pipe used in the model. Such a moment is large to be resisted by either the pipe alone or the pipe reinforced by an additional structural support, unless such support is accompanied by void decrease and a mean to stop the subgrade from eroding into the pipe.
Show less - Date Issued
- 2005
- Identifier
- CFE0000365, ucf:46343
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000365
