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- Title
- THE FLORIDA JURY: TECHNICAL EVIDENCE AND BIAS.
- Creator
-
Albaugh, Andrew, Cook, Kathy, University of Central Florida
- Abstract / Description
-
The recent societal development of highly specialized evidence has brought new problems to the forefront of the jury system. Because of the constitutional right to jury trials citizens of the United States and Florida have, it is imperative that the problems facing juries be discussed and explored. The question of whether or not juries can be trusted to comprehend highly technical evidence must be answered for the Florida jury to move forward into modern era. The subsequent question of what...
Show moreThe recent societal development of highly specialized evidence has brought new problems to the forefront of the jury system. Because of the constitutional right to jury trials citizens of the United States and Florida have, it is imperative that the problems facing juries be discussed and explored. The question of whether or not juries can be trusted to comprehend highly technical evidence must be answered for the Florida jury to move forward into modern era. The subsequent question of what biases regarding highly specialized evidence have arisen must also be examined and addressed. Furthermore, solutions designed to increase a jury's comprehension and decrease their bias must be discussed and propagated. The purpose of this thesis is to explore the answers to those questions and provide potential solutions to the issues facing the modern Florida jury. Law journals, statutes, and case law all suggest that juror comprehension decreases substantially when faced with highly complex evidence. Biases are also commonly associated with these forms of evidence and are leading towards unfair verdicts. Despite these problems, there are solutions that are readily available in the areas of alternative dispute resolution. Further solutions may be created through a revision of the jury instruction process. This thesis seeks to raise awareness of the problems facing the Florida jury and contribute solutions that are practical and easily used.
Show less - Date Issued
- 2013
- Identifier
- CFH0004427, ucf:45098
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004427
- Title
- Gee, Officer Krupke: An Actor's Casebook.
- Creator
-
Eichenlaub, Eric, Brotherton, Mark, Ingram, Kate, Niess, Christopher, University of Central Florida
- Abstract / Description
-
In 2016, I was cast as Officer Krupke in a production of West Side Story at Orlando Shakespeare Theater in Partnership with UCF. Even though Krupke can be thought of as a minor character in the play, bringing him to life required a great deal of research and imagination. In order to ground myself in the reality of the role, I researched the effects of implicit bias in modern policing, applied that research to Uta Hagen's Nine Questions, and brought that knowledge into the rehearsal hall and...
Show moreIn 2016, I was cast as Officer Krupke in a production of West Side Story at Orlando Shakespeare Theater in Partnership with UCF. Even though Krupke can be thought of as a minor character in the play, bringing him to life required a great deal of research and imagination. In order to ground myself in the reality of the role, I researched the effects of implicit bias in modern policing, applied that research to Uta Hagen's Nine Questions, and brought that knowledge into the rehearsal hall and onto the stage. I examined how my character's interactions with Lieutenant Schrank influenced his actions and attitudes toward both street gangs in the play and reflected on how my research and these performances changed my point of view and helped me recognize my own biases. This thesis reflects that process and will serve as a tool available to any actor seeking to create his or her own interpretation of Officer Krupke.
Show less - Date Issued
- 2018
- Identifier
- CFE0007327, ucf:52140
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007327
- Title
- Style Speaks: Clothing Judgments, Gender Stereotypes, and Expectancy Violations of Professional Women.
- Creator
-
Lower, Jamie, Weger, Harry, Sandoval, Jennifer, Miller, Ann, University of Central Florida
- Abstract / Description
-
Clothing is a powerful nonverbal communicative tool and form of self-expression that provides others with clues about our personality, mood, education, culture, financial status, and social ranking, amongst numerous other impression cues. Research shows that physical appearance plays a prominent role in the formation of initial judgments and is significant in shaping a person's overall impression on others (Richmond, McCroskey, (&) Payne, 1991). The present study sought to quantitatively...
Show moreClothing is a powerful nonverbal communicative tool and form of self-expression that provides others with clues about our personality, mood, education, culture, financial status, and social ranking, amongst numerous other impression cues. Research shows that physical appearance plays a prominent role in the formation of initial judgments and is significant in shaping a person's overall impression on others (Richmond, McCroskey, (&) Payne, 1991). The present study sought to quantitatively explore the effect that different styles of dress have on initial judgments formed about women in workplace settings. Using expectancy violation theory, the study investigates workplace gender bias and whether or not certain styles of women's dress garner different initial reactions. Results showed that models in feminine attire are perceived to be lower in ratings of dominance and expertise, and models in more masculine attire are perceived to be lower in ratings of kindness and friendliness.
Show less - Date Issued
- 2018
- Identifier
- CFE0007043, ucf:51971
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007043
- Title
- The Role of Teacher Perceptions of Response to Intervention, Racial/Ethnic Attitudes, and Self-Efficacy in Special Education Referral Decisions.
- Creator
-
Cash, Kristine, Gill, Michele, Edwards, Oliver, Clark, M. H., Sims, Valerie, University of Central Florida
- Abstract / Description
-
This study is an exploration of the aspects related to the disproportionate representation of minority students in special education. The investigation specifically focused on the relationship between teacher perceptions of Response to Intervention (RTI), teacher racial attitudes, and teacher self-efficacy with respect to their special education referral decisions. Teachers assigned to grades K-5 (n=51), from three Florida public school districts, completed an online survey. The survey...
Show moreThis study is an exploration of the aspects related to the disproportionate representation of minority students in special education. The investigation specifically focused on the relationship between teacher perceptions of Response to Intervention (RTI), teacher racial attitudes, and teacher self-efficacy with respect to their special education referral decisions. Teachers assigned to grades K-5 (n=51), from three Florida public school districts, completed an online survey. The survey included reading four vignettes each describing a fictitious 3rd grade, male, Black/African American student and rating the severity of the academic concern, the severity of the behavior concern, and the likelihood that they would refer the student for a special education evaluation. Participants also completed a revised RTI Survey, the Color-Blind Racial Attitudes Scale (CoBRAS), and the Teachers' Sense of Efficacy Scale (TSES). Spearman's correlation coefficients were calculated as well as an ordinal logistic regression. A statistically significant relationship was found between the Unawareness of Institutional Discrimination subscale score of the CoBRAS and the behavior concern for a student described as having mild behavior and academic concerns. A statistically significant relationship was found between the rating of the behavior concern and the Efficacy in Student Engagement and Efficacy in Classroom Management subscale scores on the TSES for the vignette describing a student with a severe reading concern and a mild behavior concern. The teachers' perceptions of RTI, racial attitudes, and sense of efficacy did not appear to have a statistically significant impact on their rating of the likelihood of referral for any of the students described in the vignettes.
Show less - Date Issued
- 2019
- Identifier
- CFE0007608, ucf:52545
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007608
- Title
- An Ethnographic Study Examining the Effect of Teachers' Socio-Political Bias on Latinx Students and School Culture.
- Creator
-
McMaster, Jessica, Olan, Elsie, Jeanpierre, Bobby, Grissom, Donita, University of Central Florida
- Abstract / Description
-
Academics such as Geneva Gay, Christine Sleeter, Samy Alim, and Django Paris have conducted research that illustrates the importance of educators being not only aware of the culture of their students but implementing curriculum that supports the diverse cultures of their students. A common finding among this research is that a culturally sustaining pedagogy is essential to the inclusion of all students in the classroom and the level of academic success they have in schools. This study aims to...
Show moreAcademics such as Geneva Gay, Christine Sleeter, Samy Alim, and Django Paris have conducted research that illustrates the importance of educators being not only aware of the culture of their students but implementing curriculum that supports the diverse cultures of their students. A common finding among this research is that a culturally sustaining pedagogy is essential to the inclusion of all students in the classroom and the level of academic success they have in schools. This study aims to investigate the effect of teacher beliefs on the academic performance of Latinx students and on the culture and atmosphere of the school. The purpose of conducting this research is to show the necessity for implementing a culturally sustaining pedagogy and curriculum in schools. My research requires teachers and administrators to answer survey questions concerning their teaching practice, student population, and beliefs about teaching students, specifically Latinx students. I hope to discover how teacher attitudes, both positive and negative, can affect the academic performance of Latinx student and the culture of the school. Lastly, with such an emphasis I would like to use this information to help educators embrace the differences of their students and see the value in incorporating students lived experiences in the class curriculum. Using a survey modeled after Bandura's Survey for Teaching Self-Efficacy this thesis explores the following questions: Research Question One (RQ1): What effect does teachers' attitudes have on the culture of their school?, Research Question Two (RQ2): What effect does teachers' socio-political views have on Latinx student performance?
Show less - Date Issued
- 2019
- Identifier
- CFE0007684, ucf:52506
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007684
- Title
- AN INQUIRY INTO DISCOURSE CHOICES AS INDICATORS OF GENDER ATTITUDES IN A NON-PROFIT CONSERVATIVE CHRISTIAN BUSINESS.
- Creator
-
Kruger, Dawn, Marinara, Martha, University of Central Florida
- Abstract / Description
-
This paper is an inquiry into the discourse styles of men and women who work together in a conservative Protestant Christian business. Many conservative Protestant Christian churches teach that the Bible forbids women from holding positions of authority over men. Yet in the communications department of this particular business, women fill the top three management positions, supervising a mixed-gender staff of 15. Research has shown that men and women subconsciously use language markers that...
Show moreThis paper is an inquiry into the discourse styles of men and women who work together in a conservative Protestant Christian business. Many conservative Protestant Christian churches teach that the Bible forbids women from holding positions of authority over men. Yet in the communications department of this particular business, women fill the top three management positions, supervising a mixed-gender staff of 15. Research has shown that men and women subconsciously use language markers that indicate personal attitudes toward the same and the opposite genders. This research project draws on that information while it analyzes the oral and electronic discourse of the communications staff. The purpose of this study is to observe whether or not the traditional teachings of conservative Protestant Christian churches has influenced the attitudes of these men and women with regard to women in positions of authority over men in a Christian business. Two staff meetings and a lunchroom conversation were audio taped and transcribed to note oral discourse patterns. One hundred and eleven emails were examined to mark patterns of written discourse. This data was then evaluated against published research in the area of gendered discourse markers. The results indicate that two of the three women in leadership positions over men were comfortable with their positions of authority, but the third woman's discourse patterns showed signs of insecurity. Furthermore, the men in the department did not indicate signs that they seek to exercise power over women, nor did they show signs of difficulty in submitting to the authority of the women. The women staff members, however, showed definite indications of being insecure in a mixed group, and of being meekly subordinate to anyone in authority over them. These results, while helpful, are not definitive in that they do not account for the possibility of other influencing factors, such as personality types, job roles and expectations, age differences, or church teachings on meekness and submission to authority. However, the results of this research indicate that some conservative Christian men are ready for and able to embrace the concept of having women in positions of authority over them, even in a Christian environment, and a few conservative, Christian women are ready to step into those positions. Also from this research it could be concluded that, on the average, conservative women struggle more with the shift of authority than men do. More research would need to be done to address that question fully.
Show less - Date Issued
- 2005
- Identifier
- CFE0000631, ucf:52852
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000631
- Title
- STUDY OF DESIGN FOR RELIABILITY OF RF AND ANALOG CIRCUITS.
- Creator
-
Tang, Hongxia, Yuan, Jiann-Shiun, Wu, Xinzhang, Sundaram, Kalpathy, Chow, Lee, University of Central Florida
- Abstract / Description
-
Due to continued device dimensions scaling, CMOS transistors in the nanometer regime have resulted in major reliability and variability challenges. Reliability issues such as channel hot electron injection, gate dielectric breakdown, and negative bias temperature instability (NBTI) need to be accounted for in the design of robust RF circuits. In addition, process variations in the nanoscale CMOS transistors are another major concern in today's circuits design.An adaptive gate-source biasing...
Show moreDue to continued device dimensions scaling, CMOS transistors in the nanometer regime have resulted in major reliability and variability challenges. Reliability issues such as channel hot electron injection, gate dielectric breakdown, and negative bias temperature instability (NBTI) need to be accounted for in the design of robust RF circuits. In addition, process variations in the nanoscale CMOS transistors are another major concern in today's circuits design.An adaptive gate-source biasing scheme to improve the RF circuit reliability is presented in this work. The adaptive method automatically adjusts the gate-source voltage to compensate the reduction in drain current subjected to various device reliability mechanisms. A class-AB RF power amplifier shows that the use of a source resistance makes the power-added efficiency robust against threshold voltage and mobility variations, while the use of a source inductance is more reliable for the input third-order intercept point.A RF power amplifier with adaptive gate biasing is proposed to improve the circuit device reliability degradation and process variation. The performances of the power amplifier with adaptive gate biasing are compared with those of the power amplifier without adaptive gate biasing technique. The adaptive gate biasing makes the power amplifier more resilient to process variations as well as the device aging such as mobility and threshold voltage degradation. Injection locked voltage-controlled oscillators (VCOs) have been examined. The VCOs are implemented using TSMC 0.18 (&)#181;m mixed-signal CMOS technology. The injection locked oscillators have improved phase noise performance than free running oscillators.A differential Clapp-VCO has been designed and fabricated for the evaluation of hot electron reliability. The differential Clapp-VCO is formed using cross-coupled nMOS transistors, on-chip transformers/inductors, and voltage-controlled capacitors. The experimental data demonstrate that the hot carrier damage increases the oscillation frequency and degrades the phase noise of Clapp-VCO.A p-channel transistor only VCO has been designed for low phase noise. The simulation results show that the phase noise degrades after NBTI stress at elevated temperature. This is due to increased interface states after NBTI stress. The process variability has also been evaluated.
Show less - Date Issued
- 2012
- Identifier
- CFE0004223, ucf:49000
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004223
- Title
- Advanced castes at the outset of eusociality in wasps (Vespidae).
- Creator
-
Piekarski, Patrick, Sharanowski, Barbara, Carpenter, James, Hoffman, Eric, University of Central Florida
- Abstract / Description
-
A dominating and widespread view is that evolutionary change is gradual and waits upon mutation. Likewise, it is thought that workers and queens of eusocial insects diverged gradually and stepwise. That is, rudimentary castes preceded advanced castes. This paradigm hinges on eusociality having evolved once in Vespidae, and primitively eusocial paper wasps lacking ontogenetic caste biasing (differentiation of castes during larval development). Using a phylogenomic approach this study shows...
Show moreA dominating and widespread view is that evolutionary change is gradual and waits upon mutation. Likewise, it is thought that workers and queens of eusocial insects diverged gradually and stepwise. That is, rudimentary castes preceded advanced castes. This paradigm hinges on eusociality having evolved once in Vespidae, and primitively eusocial paper wasps lacking ontogenetic caste biasing (differentiation of castes during larval development). Using a phylogenomic approach this study shows strong evidence for two origins of eusociality in vespid wasps, wherein one origin is likely characterized by the sudden appearance of castes with physiological, and perhaps even morphological, differences established before adulthood (i.e. advanced castes). Ontogenetic caste biasing was likely present at the outset of eusociality in the most recent common ancestor of paper wasps, yellowjackets and hornets. This suggests that the definitive, non-temporal castes of eusocial wasps evolved from interactions between mothers and daughters, rather than same generation females. These results challenge the idea that castes began with only rudimentary differences. A model of stepwise caste divergence, which assumes an independent mutation event for each phenotypic caste difference, is unwarranted. It is hypothesized that phenotypic plasticity and cryptic genetic variation may explain how some eusocial societies emerged, and began with advanced castes. The results suggest that evolution can produce alternative phenotypes with many aspects of the phenotype being discrete at the outset. Thus, the emergence and divergence of castes in eusocial vespids was not necessarily a gradual process.
Show less - Date Issued
- 2017
- Identifier
- CFE0006640, ucf:51240
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006640
- Title
- Reactive sputter deposition of lithium phosphorus oxynitride thin films, a Li battery solid state electrolyte.
- Creator
-
Mani, Prabhu Doss, Coffey, Kevin, Heinrich, Helge, Hickman, James, Sundaram, Kalpathy, University of Central Florida
- Abstract / Description
-
Lithium phosphorus oxy-nitride (LiPON) thin films are widely studied and used as a thin film electrolyte for lithium ion battery applications. LiPON thin films may be prepared by many techniques, but RF sputter deposition is most frequently used and was investigated in this dissertation, in spite of its low deposition rate, because of it offers more reliable and controllable processing. This dissertation includes the methodologies of sputter deposition and materials characterization of the...
Show moreLithium phosphorus oxy-nitride (LiPON) thin films are widely studied and used as a thin film electrolyte for lithium ion battery applications. LiPON thin films may be prepared by many techniques, but RF sputter deposition is most frequently used and was investigated in this dissertation, in spite of its low deposition rate, because of it offers more reliable and controllable processing. This dissertation includes the methodologies of sputter deposition and materials characterization of the LiPON thin film electrolytes.The LiPON thin films were deposited under varying conditions of process gas, substrate bias, and deposition temperature. To understand the variations in ionic conductivity observed, the films were extensively characterized to examine structural and compositional differences, including examination by x-ray photoelectron spectroscopy (XPS), inductively coupled plasma optical emission spectroscopy (ICP/OES), and spectroscopic ellipsometry. In addition, film density, and the intrinsic stress of the deposited films were also studied.The highest ionic conductivity of 9.8 x 10-6 S/cm was obtained at elevated deposition temperature and is correlated to a reduced density of defects, as indicated from the optical characterization.
Show less - Date Issued
- 2015
- Identifier
- CFE0005835, ucf:50929
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005835
- Title
- Beauty and the Beast: The Attractiveness Bias in an Online Peer Mentoring Program.
- Creator
-
Garcia, Carollaine, Jentsch, Kimberly, Jentsch, Florian, Fritzsche, Barbara, Burke, Shawn, University of Central Florida
- Abstract / Description
-
The bias against attractiveness is fairly implicit and furthermore, powerfully impacts people's subsequent impressions of and behaviors toward others (Cash, Gillen, (&) Burns, 1977; Dion et al., 1972). Pallet, Link and Lee (2010) examined the effect of various facial spatial configurations on attractiveness and found that raters rated faces as most attractive when the eye-to-mouth ratio approximated 36% of the face length (the "golden ratio"), which coincides with the measurements of an...
Show moreThe bias against attractiveness is fairly implicit and furthermore, powerfully impacts people's subsequent impressions of and behaviors toward others (Cash, Gillen, (&) Burns, 1977; Dion et al., 1972). Pallet, Link and Lee (2010) examined the effect of various facial spatial configurations on attractiveness and found that raters rated faces as most attractive when the eye-to-mouth ratio approximated 36% of the face length (the "golden ratio"), which coincides with the measurements of an average and thus more attractive face. The present study examined the extent to which the distance of these objectively measured facial features affected mentors' perceptions of their prot(&)#233;g(&)#233;s, the subsequent mentoring given to them, and the prot(&)#233;g(&)#233;s' own behavior (e.g. seek feedback, request specific information).The gender composition of the mentor-prot(&)#233;g(&)#233; dyad was expected to moderate these relationships. I also examined whether, given the expected effects of facial measurements, withholding access to visual cues would affect mentor perceptions and behavior. Participants were 118 mentor/prot(&)#233;g(&)#233; dyads from a large Southeastern university who volunteered to participate in a formal online peer mentoring program. After seeing their prot(&)#233;g(&)#233;s' profiles (and for those in the experimental condition, a picture), mentors chatted with their prot(&)#233;g(&)#233;s once a week for 30 minutes for a total of 4 weeks. Results indicated that prot(&)#233;g(&)#233;s with facial features moderately distant from the golden ratio were perceived as more similar by mentors in same-gender dyads and received greater mentoring than did prot(&)#233;g(&)#233;s closest and farthest from the golden ratio. In opposite-gender dyads, however, mentors reported greater similarity toward those that were farthest from the golden ratio but provided the greatest mentoring to those closest to the golden ratio. The relationship between facial measurements and prot(&)#233;g(&)#233; proactivity was moderated by whether or not their mentor had access to their picture. While prot(&)#233;g(&)#233;s closest to the ratio were more proactive in the picture condition, those that were farthest from it were more proactive in the non-picture condition. Proactivity was as expected associated with greater levels of mentoring, which was ultimately related to a more fulfilled and beneficial relationship for prot(&)#233;g(&)#233;s (i.e. less stress, greater self-efficacy and satisfaction). The results of this study indicate that facial measurements are associated with both differences in mentor and in prot(&)#233;g(&)#233; behavior and that the specific nature of these relationships differs as a function of gender composition. Implications for practice and theory will be discussed.
Show less - Date Issued
- 2012
- Identifier
- CFE0004504, ucf:49275
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004504
- Title
- I got my eye on you.
- Date Created
- 1905
- Identifier
- DP0015479
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015479
- Title
- Honey, does yo lub yo man?.
- Date Created
- 1897
- Identifier
- DP0015451
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015451
- Title
- The Johnson family visit the Dahoman village.
- Date Created
- 1893
- Identifier
- DP0015450
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015450
- Title
- A dark outlook.
- Description
- Printed color Black Americana postcards. Front: Five black children looking out of a window. Card entitled "A Dark Outlook". Addressed to Mr. Ralph Berridge. Stamped "EVANSVILLE IND. SEP 15 6 PM 1907".
- Date Created
- 1907
- Identifier
- DP0015481
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015481
- Title
- Smoking Joe's Restaurant menu and fan.
- Identifier
- DP0015343
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015343
- Title
- INVESTIGATION OF THERMAL, ELASTIC AND LOAD-BIASED TRANSFORMATION STRAINS IN NITI SHAPE MEMORY ALLOYS.
- Creator
-
Qiu, Shipeng, Vaidyanathan, Raj, University of Central Florida
- Abstract / Description
-
Polycrystalline NiTi shape memory alloys have the ability to recover their original, pre-deformed shape in the presence of external loads when heated through a solid-solid phase transformation from a lower-symmetry B19' martensite phase to a higher-symmetry B2 austenite phase. The strain associated with a shape memory alloy in an actuator application typically has thermal, elastic and inelastic contributions. The objective of this work was to investigate the aforementioned strains by...
Show morePolycrystalline NiTi shape memory alloys have the ability to recover their original, pre-deformed shape in the presence of external loads when heated through a solid-solid phase transformation from a lower-symmetry B19' martensite phase to a higher-symmetry B2 austenite phase. The strain associated with a shape memory alloy in an actuator application typically has thermal, elastic and inelastic contributions. The objective of this work was to investigate the aforementioned strains by recourse to in situ neutron diffraction experiments during selected combinations of heating, cooling and/or mechanical loading. The primary studies were conducted on polycrystalline Ni49.9Ti50.1 specimens on the Spectrometer for MAterials Research at Temperature and Stress (SMARTS) at Los Alamos National Laboratory. Quantitative information on the phase-specific strain, texture and phase fraction evolution was obtained from the neutron data using Rietveld refinement and single-peak analyses, and compared with macroscopic data from extensometry. First, the lattice strain evolution during heating and cooling in an unloaded sample (i.e., free-recovery experiment) was studied. The lattice strain evolution remained linear with temperature and was not influenced by intergranular stresses, enabling the determination of a thermal expansion tensor that quantified the associated anisotropy due to the symmetry of B19' NiTi. The tensor thus determined was subsequently used to obtain an average coefficient of thermal expansion that was consistent with macroscopic dilatometric measurements and a 30,000 grain polycrystalline self-consistent model. The accommodative nature of B19' NiTi was found to account for macroscopic shape changes lagging (with temperature) the start and finish of the transformation. Second, the elastic response of B19' martensitic NiTi variants during monotonic loading was studied. Emphasis was placed on capturing and quantifying the strain anisotropy which arises from the symmetry of monoclinic martensite and internal stresses resulting from intergranular constraints between individual variants and load re-distribution among variants as the texture evolved during variant reorientation and detwinning. The methodology adopted took into account both tensile and compressive loading given the asymmetric response in the texture evolution. Plane specific elastic moduli were determined from neutron measurements and compared with those determined using a self-consistent polycrystalline deformation model and from recently reported elastic stiffness constants determined via ab initio calculations. The comparison among the three approaches further helped understand the influence of elastic anisotropy, intergranular constraint, and texture evolution on the deformation behavior of polycrystalline B19' NiTi. Connections were additionally made between the assessed elastic properties of martensitic NiTi single crystals (i.e., the single crystal stiffness tensor) and the overall macroscopic response in bulk polycrystalline form. Lastly, the role of upper-cycle temperature, i.e., the maximum temperature reached during thermal cycling, was investigated during load-biased thermal cycling of NiTi shape memory alloys at selected combinations of stress and temperature. Results showed that the upper-cycle temperature, under isobaric conditions, significantly affected the amount of transformation strain and thus the work output available for actuation. With the objective of investigating the underlying microstructural and micromechanical changes due to the influence of the upper-cycle temperature, the texture evolution was systematically analyzed. While the changes in transformation strain were closely related to the evolution in texture of the room temperature martensite, retained martensite in the austenite state could additionally affect the transformation strain. Additionally, multiple thermal cycles were performed under load-biased conditions in both NiTi and NiTiPd alloys, to further assess and understand the role of retained martensite. Dimensional and thermal stabilities of these alloys were correlated with the volume fraction and texture of retained martensite, and the internal strain evolution in these alloys. The role of symmetry, i.e., B19' monoclinic martensite vs. B19 orthorhombic martensite in these alloys was also assessed. This work not only established a methodology to study the thermal and elastic properties of the low symmetry B19' monoclinic martensite, but also provided valuable insight into quantitative micromechanical and microstructural changes responsible for the thermomechanical response of NiTi shape memory alloys. It has immediate implications for optimizing shape memory behavior in the alloys investigated, with extension to high temperature shape memory alloys with ternary and quaternary elemental additions, such as Pd, Pt and Hf. This work was supported by funding from NASAÂÂ's Fundamental Aeronautics Program, Supersonics Project (NNX08AB51A) and NSF (CAREER DMR-0239512). It benefited additionally from the use of the Lujan Neutron Scattering Center at Los Alamos National Laboratory, which is funded by the Office of Basic Energy Sciences (Department of Energy) and is operated by Los Alamos National Security LLC under DOE Contract DE-AC52-06NA25396.
Show less - Date Issued
- 2010
- Identifier
- CFE0003362, ucf:48440
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003362
- Title
- An On-orbit Calibration Procedure for Spaceborne Microwave Radiometers Using Special Spacecraft Attitude Maneuvers.
- Creator
-
Farrar, Spencer, Jones, W Linwood, Mikhael, Wasfy, Wahid, Parveen, Gaiser, Peter, University of Central Florida
- Abstract / Description
-
This dissertation revisits, develops, and documents methods that can be used to calibrate spaceborne microwave radiometers once in orbit. The on-orbit calibration methods discussed within this dissertation can provide accurate and early results by utilizing Calibration Attitude Maneuvers (CAM), which encompasses Deep Space Calibration (DSC) and a new use of the Second Stokes (SS) analysis that can provide early and much needed insight on the performance of the instrument. This dissertation...
Show moreThis dissertation revisits, develops, and documents methods that can be used to calibrate spaceborne microwave radiometers once in orbit. The on-orbit calibration methods discussed within this dissertation can provide accurate and early results by utilizing Calibration Attitude Maneuvers (CAM), which encompasses Deep Space Calibration (DSC) and a new use of the Second Stokes (SS) analysis that can provide early and much needed insight on the performance of the instrument. This dissertation describes pre-existing and new methods of using DSC maneuvers as well as a simplified use of the SS procedure. Over TRMM's 17 years of operation it has provided invaluable data and has performed multiple CAMs over its lifetime. These maneuvers are analyzed to implement on-orbit calibration procedures that will be applied for future missions. In addition, this research focuses on the radiometric calibration of TMI that will be incorporated in the final processing (Archive/Legacy of the NASA TMI 1B11 brightness temperature data product). This is of importance since TMI's 17-year sensor data record must be vetted of all known calibration errors so to provide the final stable data for science users, specifically, climatological data records.
Show less - Date Issued
- 2015
- Identifier
- CFE0005611, ucf:50208
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005611
- Title
- The little black behind.
- Date Created
- 1900s
- Identifier
- DP0015490
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015490
- Title
- The temptation of St. Anthony.
- Creator
-
Flagg, James M.
- Date Created
- 1895
- Identifier
- DP0015457
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015457
- Title
- "Deed, I dun eat no chicken".
- Date Created
- 1909
- Identifier
- DP0015485
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015485
