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Title: A Study of Perceptions on Incident Response Exercises, Information Sharing, Situational Awareness, and Incident Response Planning in Power Grid Utilities.
Creator: Garmon, Joseph, Karwowski, Waldemar, Hancock, Peter, Elshennawy, Ahmad, Wan, Thomas, University of Central Florida
Abstract / Description: The power grid is facing increasing risks from a cybersecurity attack. Attacks that shut off electricity in Ukraine have already occurred, and successful compromises of the power grid that did not shut off electricity to customers have been privately disclosed in North America. The objective of this study is to identify how perceptions of various factors emphasized in the electric sector affect incident response planning. Methods used include a survey of 229 power grid personnel and the use...
Show moreThe power grid is facing increasing risks from a cybersecurity attack. Attacks that shut off electricity in Ukraine have already occurred, and successful compromises of the power grid that did not shut off electricity to customers have been privately disclosed in North America. The objective of this study is to identify how perceptions of various factors emphasized in the electric sector affect incident response planning. Methods used include a survey of 229 power grid personnel and the use of partial least squares structural equation modeling to identify causal relationships. This study reveals the relationships between perceptions by personnel responsible for cybersecurity, regarding incident response exercises, information sharing, and situational awareness, and incident response planning. The results confirm that the efforts by the industry on these topics have advanced planning for a potential attack.
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Date Issued: 2019
Identifier: CFE0007805, ucf:52349
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007805

Title: Multicultural Personality and Psychological Functioning.
Creator: Trottier, Lauren, Negy, Charles, Cassisi, Jeffrey, Renk, Kimberly, University of Central Florida
Abstract / Description: As the U.S. becomes increasingly diverse, individuals will need to interact effectively with a wide range of people. The theory of multicultural personality refined by Ponterotto (2010) proposes that some individuals may be better suited than others to adapt to the changing demographic landscape. Individuals with a multicultural personality are theorized to have the ability to interact effectively within a wide range of contexts and draw on diverse experiences and resources to solve everyday...
Show moreAs the U.S. becomes increasingly diverse, individuals will need to interact effectively with a wide range of people. The theory of multicultural personality refined by Ponterotto (2010) proposes that some individuals may be better suited than others to adapt to the changing demographic landscape. Individuals with a multicultural personality are theorized to have the ability to interact effectively within a wide range of contexts and draw on diverse experiences and resources to solve everyday problems in multiple ways as well as seek out diversity in their lives. Because of their skills and disposition, Ponterotto (2010) suggests that those with a multicultural personality may experience better psychological functioning than their non-multicultural counterparts. The current study utilized Structural Equation Modeling to test the hypothesis that individuals who endorse greater multicultural personality also exhibit less prejudice, greater ethnic identity, and better psychological functioning, defined as a combination of subjective well-being and clinical symptomology. Results indicated moderate fit to the data and examination of specific paths within the model suggests that the relationship between multicultural personality and subjective well-being may be stronger than that between multicultural personality and clinical symptomology. Differences by ethnicity were also found on measures of ethnic identity and mental health. These results highlight the need to further refine the concept of multicultural personality as well as examine the complex relationships between multicultural personality, subjective well-being, and clinical symptomology.
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Date Issued: 2013
Identifier: CFE0004950, ucf:49567
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004950

Title: POLICE ORGANIZATIONAL PERFORMANCE IN THE STATE OF FLORIDA:CONFIRMATORY ANALYSIS OF THE RELATIONSHIP OF THE ENVIRONMENT AND DESIGN STRUCTURE TO PERFORMANCE.
Creator: Goltz, Jeffrey, Wan, Thomas, University of Central Florida
Abstract / Description: To date, police organizations have not been rigorously analyzed by organizational scholars and most analysis of these organizations has been captured through a single construct. The purpose of this study is to develop confirmatory police organizational analysis by validating a multi-dimensional conceptual framework that explains the relationships among three constructs: environmental constraints, the design structures of police organizations, and organizational performance indicators. The...
Show moreTo date, police organizations have not been rigorously analyzed by organizational scholars and most analysis of these organizations has been captured through a single construct. The purpose of this study is to develop confirmatory police organizational analysis by validating a multi-dimensional conceptual framework that explains the relationships among three constructs: environmental constraints, the design structures of police organizations, and organizational performance indicators. The modeling is deeply rooted in contingency theory, and the influence of isomorphism and institutional theory on the covariance structure model are investigated. One hundred and thirteen local police organizations from the State of Florida are included in this non-experimental, cross-sectional study to determine the direct effect of the environmental constraints on the performance of police organizations, the indirect effect of environmental constraints on the performance of police organizations via the organizational design structure of police organizations, and the direct affect of organizational design structure on performance of police organizations. For the first time, structural equation modeling and data envelopment analysis are used together to confirm the effects of the environment on police organization structure and performance. The results indicate that environmental social economic disparity indicators have a large positive effect on police resources and a medium effect on police efficiency. Propensity of crime indicators has a large negative effect on police resources, and population density has a small to medium negative effect on crime clearance. Structure has a much smaller effect on performance than the environment. The results of the efficiency analysis revealed unexpected findings. Three of the top five largest police organizations in the study scored maximum efficiency. The cause of this unexpected result is explained and confirmed in the covariance model. The study methodology and results enhances the understanding of the relationship among the constructs while subjecting environmental and police organizational data to two comprehensive analytical techniques. The policy implications and practical contributions of the study provide new knowledge and information to organizational management of police organizations. Furthermore, the study establishes a new approach to police organizational analysis and police services management research called Police Services Management Research (PSMR) that encompasses a variety of disciplines with a primary responsibility of theory building and the selection of theoretical framework.
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Date Issued: 2006
Identifier: CFE0001363, ucf:47000
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001363

Title: FORENSIC ANALYSIS OF AUTOMOBILE PAINTS BY ATOMIC AND MOLECULAR SPECTROSCOPIC METHODS AND STATISTICAL DATA ANALYSES.
Creator: McIntee, Erin, Sigman, Michael, University of Central Florida
Abstract / Description: The analysis of 110 automotive paint samples was conducted for the research presented here. Laser-induced breakdown spectroscopy (LIBS) was the central instrument utilized for analysis although scanning electron microscopy / energy dispersive x-ray spectroscopy (SEM/EDS) and Fourier transform infrared spectroscopy – attenuated total reflection (FTIR-ATR) analyses were also performed. Two separate methods of LIBS analysis of samples were used: a cross sectional analysis and a drill down...
Show moreThe analysis of 110 automotive paint samples was conducted for the research presented here. Laser-induced breakdown spectroscopy (LIBS) was the central instrument utilized for analysis although scanning electron microscopy / energy dispersive x-ray spectroscopy (SEM/EDS) and Fourier transform infrared spectroscopy – attenuated total reflection (FTIR-ATR) analyses were also performed. Two separate methods of LIBS analysis of samples were used: a cross sectional analysis and a drill down analysis. SEM/EDS analysis focused on the cross section while FTIR-ATR analysis concentrated on the clearcoat layer. Several different data/statistical analyses were evaluated including principal components analysis (PCA), two tailed t-tests based on several different metrics (Hit Quality Index (HQI), Pearson's correlation and Sorenson index), multivariate analysis of variance and receiver operating characteristic (ROC) curves. Full spectrum data analysis from LIBS spectra resulted in 99.7% discrimination between different sample comparisons and 12% between same sample comparisons based on HQI and t-tests. Peak analysis of LIBS spectra resulted in 87.5% discrimination between different sample comparisons and 5% between same sample comparisons based on MANOVA. When combining the results of the FTIR-ATR and SEM/EDS analyses, 88% of the samples could be discriminated.
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Date Issued: 2008
Identifier: CFE0002430, ucf:47739
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002430

Title: EFFECTS OF BINARY SOLVENT SYSTEM ON MORPHOLOGY OF PARTICLES.
Creator: Besana, Patrick, Deng, Weiwei, University of Central Florida
Abstract / Description: Recent advancements in cancer research has led to the synthesis of a new drug known as docetaxel. Meant to replace paclitaxel, its more natural counterpart whose ingredients are difficult to obtain, the drug is known to effectively treat a wide array of cancers, including breast cancer, ovarian cancer, and prostate cancer. The establishment of a synthetic alternative to paclitaxel has increased its bioavailability, thereby lowering the cost needed to utilize the drug. Still, the limiting...
Show moreRecent advancements in cancer research has led to the synthesis of a new drug known as docetaxel. Meant to replace paclitaxel, its more natural counterpart whose ingredients are difficult to obtain, the drug is known to effectively treat a wide array of cancers, including breast cancer, ovarian cancer, and prostate cancer. The establishment of a synthetic alternative to paclitaxel has increased its bioavailability, thereby lowering the cost needed to utilize the drug. Still, the limiting factor in minimizing costs is the method in which the drug is processed. Current methods in drug processing have their limitations, which include the introduction of impurities and a low effective yield due to poor powder geometry. Thus, the goal of this study looks to explore a new way to process the drug in a more efficient manner. In this study, a new method for processing docetaxel is explored on in great detail. A more direct method of using electrospray deposition is utilized for the creation of monodisperse nanoparticles, with the main intention of increasing the efficiency at which the drug is processed and prepared for drug delivery to the patient by means of injection. A key feature in electrospray deposition is its ability to produce droplets that are sized homogenously. These droplets eventually evaporate at homogenous rates. These two concepts have been exploited to consistently produce nanoparticles of the cancer drug, which is made possible by the fact that the minimal variation in droplet sizes has easily translated to minimal variation in dry particle sizes. Compared to other methods of drug processing, one other benefit that electrospray deposition conveys is that through evaporation, virtually all impurities and unwanted foreign material are eliminated. Moreover, a binary solvent system is investigated in more detail in this study, so as to determine its effects on both the evaporation of the solvent and the diffusion of the drug into nanoparticles. From there, material and geometric properties of the electrospray nozzle were explored upon in great detail, with the main goal of being able to produce a cone jet that consistently dissociates into monodisperse droplets. At the same time, controllable properties of the electrospray atomizer were investigated and continuously modified. Modifications in both the components of the solution and the operating temperature were also considered to enhance both the electrospray deposition process and the geometry of the particles. Scanning electron microscopy (SEM) characterization is continuously utilized to determine suitability of results obtained in experiments. Ultimately, the goal of this study is to determine the ideal conditions (solvent ratios, flow rate, operating temperature, electrospray atomizer nozzle configurations, etc.) in which spherical docetaxel particles sized at 100-200 nm can be produced.
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Date Issued: 2015
Identifier: CFH0004872, ucf:45412
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0004872

Title: EXTENDING THE TECHNOLOGY ACCEPTANCE MODEL USING PERCEIVED USER RESOURCES IN HIGHER EDUCATION WEB-BASED ONLINE LEARNING COURSES.
Creator: KU, CHENG-HSIN, Sivo, Stephen, University of Central Florida
Abstract / Description: The purpose of this research was to examine students' acceptance of the World Wide Web Course Tools (WebCT) online learning system. The Perceived Resources and Technology Acceptance Model (PRATAM) was created based on previous research to address the factors of perceived resources, perceived usefulness, perceived ease of use, attitude toward using, behavioral intention to use and actual system use. The aim for this research was to investigate the critical determinants and provide the...
Show moreThe purpose of this research was to examine students' acceptance of the World Wide Web Course Tools (WebCT) online learning system. The Perceived Resources and Technology Acceptance Model (PRATAM) was created based on previous research to address the factors of perceived resources, perceived usefulness, perceived ease of use, attitude toward using, behavioral intention to use and actual system use. The aim for this research was to investigate the critical determinants and provide the causal relationships regarding students' acceptance behaviors when using WebCT. While institutions are expecting to adopt online learning to reach more students, there are still many challenges for institutions to retain students in their online courses. The literature review conducted in this research indicated that the Technology Acceptance Model (TAM) has successfully explained students' behaviors when they use educational information systems. In addition, the additional perceived resources variable in the PRATAM also showed a significant influence on the other belief and intention variables. The study analyzed a total of 115 students responses in two surveys administered during two WebCT based courses taught at a large southeastern public university. The beliefs, attitudes, intentions, and behavioral constructs of PRATAM showed significant goodness-of-fit indices and coefficient of determination after analyzing the data in both surveys. However, the results indicated several exceptions on PRATAM's constructs and causal relationships. First, the path coefficient between perceived resources to behavioral intention to use in both pre-test and post-test were insignificant. Second, the path coefficient between behavioral intention to use and actual system use in pre-test was insignificant. Third, the path coefficient between perceived resources and perceived usefulness in post-test were insignificant. In addition, the research also suggested an additional link between perceived ease of use and behavioral intention to use at the pre-test data. Overall, this research validated the influences of PRATAM's constructs factors to students' acceptance behaviors toward WebCT. The findings of this research could provide a guideline for future implementations of online learning systems in higher education.
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Date Issued: 2009
Identifier: CFE0002635, ucf:48233
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002635

Title: Characterization of Post-Fire Priming Cup Residue Using Scanning Electron Microscopy Coupled With Energy Dispersive X-Ray Spectrometry.
Creator: Terry, Molly, Bridge, Candice, Sigman, Michael, Campiglia, Andres, University of Central Florida
Abstract / Description: Ammunition is most often comprised of a lead-based priming mixture which contributes to the traditional characteristics of gunshot residue (GSR). Due to the health risks often associated with lead, lead-free primer alternatives are becoming increasingly more popular. Thus, it is becoming more difficult to determine the presence of GSR based on traditional means, i.e. the presence of lead (Pb), barium (Ba), and antimony (Sb). Eight different ammunitions were purchased which consisted of one...
Show moreAmmunition is most often comprised of a lead-based priming mixture which contributes to the traditional characteristics of gunshot residue (GSR). Due to the health risks often associated with lead, lead-free primer alternatives are becoming increasingly more popular. Thus, it is becoming more difficult to determine the presence of GSR based on traditional means, i.e. the presence of lead (Pb), barium (Ba), and antimony (Sb). Eight different ammunitions were purchased which consisted of one lead-based and one lead-free from four different manufacturers, including Winchester, Federal, Liberty, and Sellier (&) Bellot. Half of the rounds from each manufacturer and chemical composition (i.e. lead-based or lead-free) were disassembled, e.g. the projectile and smokeless powder were removed, leaving the priming cup in place (i.e. primed only). The remaining cartridges were left intact (i.e. full cartridge). Both the full cartridges and the primed only cartridges for each ammunition were fired using a 9mm Glock and the cartridges were collected post-fire, and subsequently deprimed. Five cups and five anvils from each type of ammunition were adhered to aluminum stubs via colloidal graphite. The GSR remaining on the anvils and in the cups was then analyzed using scanning electron microscopy coupled with energy dispersive x-ray spectrometry (SEM-EDX). Three spectra were collected for each anvil and each cup resulting in 30 total spectra per type of ammunition. The primary element peaks were then selected and four different dataset matrices were created for the full cartridge anvils, full cartridge cups, primed only anvils, and primed only cups. The data was processed using unit vector normalization and was then analyzed using principal component analysis (PCA) and linear discriminant analysis (LDA) to determine the characterization between lead-free and lead-based ammunition. The anvils provided better separation and characterization based on the ability to better collect x-rays, and therefore demonstrated the capability of the ammunition to cluster by both primer mixture composition and manufacturer. The lead-based and lead-free primers showed consistencies across samples, such as the presence or absence of K, which allowed for characterization based on primer composition.
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Date Issued: 2016
Identifier: CFE0006509, ucf:51377
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006509

Title: Chemical Differentiation of Human Osseous, Non-human Osseous, and Non-osseous Materials Using Scanning Electron Microscopy - Energy Dispersive X-ray Spectrometry (SEM/EDX) and Multivariate Statistical Analysis.
Creator: Meizel-Lambert, Cayli, Schultz, John, Sigman, Michael, Toyne, J. Marla, University of Central Florida
Abstract / Description: Identification of osseous materials is generally established on gross anatomical factors; however, highly fragmented or taphonomically altered materials are often problematic and alternative methods, such as biological, histological, or chemical analysis, must be utilized. Recently, chemical methods have been proposed to sort unknown materials according to their Ca/P ratios. Ubelaker and colleagues (2002) proposed using SEM/EDX to achieve this distinction and Christensen and colleagues (2012)...
Show moreIdentification of osseous materials is generally established on gross anatomical factors; however, highly fragmented or taphonomically altered materials are often problematic and alternative methods, such as biological, histological, or chemical analysis, must be utilized. Recently, chemical methods have been proposed to sort unknown materials according to their Ca/P ratios. Ubelaker and colleagues (2002) proposed using SEM/EDX to achieve this distinction and Christensen and colleagues (2012) have validated X-ray Fluorescence Spectrometry (XRF) for this application. An alternative method of analysis involves performing principal component analysis (PCA) on element spectra to classify unknown materials based on their trace element composition. Zimmerman (2013) proposed the validity of this method with data obtained using hand held XRF. Subsequently, performing PCA on elemental data obtained using SEM/EDX demonstrates potential for material differentiation. Elemental weight percent data were collected using SEM/EDX then processed in R, version 3.0.1, by the R Foundation for Statistical Computing using PCA and Fisher Linear Discriminant Analysis. A two-tiered analysis was undertaken to improve discrimination between sample groups. The first tier involved distinguishing between osseous and non-osseous materials. After outliers were removed overall correct classification was 98.02% with one of 1504 osseous and 39 of 520 non-osseous spectra misclassifying. Since forty spectra were collected for each sample, the single misclassifying spectra would not affect the overall classification of the sample, resulting in 100% correct classification with a 0% error rate for the osseous samples. The second tier assessed differentiation of human and non-human osseous materials but demonstrated a poor correct classification rate of 72.41%. Finally, a blind study was conducted using 20 samples to assess the applicability for using this method to classify unknown materials as osseous or non-osseous. All of the samples were correctly classified resulting in 100% correct classification, further demonstrating the efficiency of SEM/EDX and statistical analysis for differentiation of osseous and non-osseous materials. Due to its high specificity, small sample requirements, and relative non-destructive testing protocol, as well as its presence in most modern crime laboratories, SEM/EDX has been proposed as a laboratory method for chemical differentiation of osseous and non-osseous materials. Additionally, the proposed method does not require advanced training or knowledge of analytical chemistry as the SEM/EDX provides clear results that can be processed using publically available statistical analysis software. By assessing and improving chemical analysis methodologies used for material differentiation, forensic anthropologists might be able to identify osseous and non-osseous samples as a preemptive step in forensic investigations involving fragmentary and taphonomically modified materials, reducing time and cost investments spent on forensically insignificant samples.
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Date Issued: 2014
Identifier: CFE0005665, ucf:50185
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005665

Title: Investigation on the Mechanical, Microstructural, and Electrical Properties of Graphene Oxide-Cement Composite.
Creator: Al Muhit, Baig Abdullah, Nam, Boo Hyun, Zhai, Lei, Chopra, Manoj, University of Central Florida
Abstract / Description: Nanotechnology refers to the use of the materials or particles ranging from a few nanometers (nm) to 100 nanometers (nm) in a wide range of applications. Use of nanomaterials in cement composite to enhance the mechanical properties, fracture toughness and other functionalities has been studied for decades. In this regard, one of the carbon-based nanomaterials, Graphene Oxide (GO), has received attentions from researchers for its superior mechanical properties (e.g. tensile strength, yield...
Show moreNanotechnology refers to the use of the materials or particles ranging from a few nanometers (nm) to 100 nanometers (nm) in a wide range of applications. Use of nanomaterials in cement composite to enhance the mechanical properties, fracture toughness and other functionalities has been studied for decades. In this regard, one of the carbon-based nanomaterials, Graphene Oxide (GO), has received attentions from researchers for its superior mechanical properties (e.g. tensile strength, yield strength, and Young's modulus). Although GO is not lucrative in increasing electrical conductivity (EC) of cement paste compared to that of graphene- another derivative of GO, reduced graphene oxide (rGO), might be a solution to increase EC. Another derivative of GO is the solution to the problem.In this research, the compressive strength and flexural strength of GO-cement composite (GOCC) and rGO-cement composite (rGOCC) have been investigated with 0.01% and 0.05% GO and rGO content. GOCC-0.05% showed 27% increase in compressive strength compared to the control cement paste after 28 days (d) of hydration. GOCC-0.01% showed only 3.4% increase in compressive strength compared to the control. rGOCC-0.05% showed 21% increase in compressive strength and 15.5% increase in Modulus of Rupture (MOR) compared to the control cement paste after 28 d of hydration. On the other hand, rGOCC-0.01% showed 7% increase in compressive strength and 0.35% increase in MOR after 28 d. GOCC-0.05% showed increasing trends in compressive strength after 28 d indicating continuation of hydration. Similarly, rGOCC-0.05% also showed increasing trends in compressive and flexural strength after 28 d, possibly due to the reason described earlier.Microstructural investigation on GOCC-0.05% and GOCC-0.01% by X-ray Diffraction (XRD) illustrated that the crystallite sizes of tobermorite-9(&)#197; and jennite, which are mineralogical counterpart of disordered Calcium-Silicate-Hydrate (C-S-H), increases from 3 d to 28 d, representing the crystallite growth due to continued hydration. However, the crystallite size of GOCC-0.05% was smaller than that of GOCC-0.01% at both 3 d and 28 d, indicating finer nucleated grains. According to Hall-Petch equation, mechanical strength increases with decreasing particle size. Finer particles or grains can increase the strength in cement composites in several other ways: (1) GO acted as heterogeneous nucleation sites because of reactive functional groups. Activation energy was decreased by these (")defects(") in the cement paste, and consequently, numerous nuclei of C-S-H. with high surface area were formed, (2) because of finer grains, cracks are forced to move along a tortuous path, which makes the structure difficult to fail, and strength increased consequently (3) Finer grains of GOCC-0.05% created compacted hydration products decreasing porosity which can indirectly increase the strength. The above reasons, separately or in conjunction, might increase the strength of GOCC-0.05% and proved that GO is responsible for increasing heterogeneous nucleation sites during cement hydration.Early age hydration (EAH) characteristics were investigated for rGOCC specimens with 0.1% and 0.5% rGO content. Scanning Electron Microscope (SEM), Energy Dispersive X-ray analysis (EDX), and X-ray Diffraction (XRD) were employed to study the EAH characteristics. SEM/EDX, and XRD analysis were performed after 15 min, 1 h, 3 h and 24 h of hydration. (EAH) study on rGOCC-0.1% showed that at 15 m(&)#172;in hydration, numerous precipitates of, possibly, C-S-H formed along the grain boundary (GB) of unhydrated cement grains. This served as visual confirmation of Thomas and Scherer's Boundary Nucleation and Growth (BNG) model that hydration of cement grains was initiated by the short burst of nucleation of C-S-H embryos along GB. EDX on rGOCC-0.1% and rGOCC-0.5% showed that Ca/Si ratio in C-S-H was ~2.0. This finding indicated that C-S-H structure in this study was concurrent with that of impure jennite. XRD analysis also evidently showed that jennite was present, possibly possessing a short range ordered (SRO) structure, referring to local crystalline structure in a very short area. After consulting Chen's work, it would be appropriate to say that C-S-H found in this study resembled more as C-S-H (II), which is disordered jennite. It was also observed that as expected with cement with nanomaterials, with continuing hydration, pore spaces were filled with hydration products such as C-S-H, ettringite, CH, sulfoaluminates etc,.Lastly, Electrical resistivity (ER) testing on 9 sets of rGOCC specimens was conducted. The specimen includes 0.5%, 1%, 5% rGO content, and the control conditioned in both oven dry (OD) and saturated surface dry (SSD). ER increased with the increase of rGO content from 0.5% and 1% compared to that of the control. However, the ER of rGOCC-5% was significantly decreased, showing 93% reduction compared to the control, which can be interpreted as a threshold value for sensing applications to be explored. As expected, large reduction of ER value occurred on the specimens with the SSD condition. This reduction can be attributed to the ionic conduction though the pore solution of the composites. As the rGO content increased, so did the potential nucleation sites for hydration (as can be seen in SEM images), which might block the number of contact points among the rGO, resulting in low conduction and high resistivity. However, as rGO content increased to 5%, the contact areas/points increased to a degree that could trump the nucleation seeding sites, resulting in decreased ER. The ER measured with the rGOCC specimens was comparable to that of cement composites incorporating carbon fibers (CF), and steel fibers, but higher content of rGO are required to have a similar ER range of those fiber cement composites. This might be due to smaller sizes of rGO sheets and lower aspect ratio compared to other nanofibers causing drastic reduction of electron tunneling mechanism compared to other fibers.
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Date Issued: 2015
Identifier: CFE0005752, ucf:50107
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005752

Title: PERCEPTIONS OF THE CONSUMPTION OF SEXUALLY-EXPLICIT MATERIAL AS AN ACT OF INFIDELITY IN THE CONTEXT OF COLLEGE ROMANTIC RELATIONSHIPS AND THEIR CONNECTION TO POPULATION VARIABLES.
Creator: Plaza, Diego, Negy, Charles, University of Central Florida
Abstract / Description: This study sought to examine whether individuals perceive the consumption (i.e., viewing) of sexually-explicit material (SEM) as an act of infidelity. The study also looked into whether ethnicity, sexual orientation, religiosity, self-esteem, and femininity/masculinity influence this opinion. As an extension of the study, the participants' susceptibility for jealousy, general attitudes toward infidelity, attitudes toward SEM, opinion toward sexuality, and fear of abandonment were also...
Show moreThis study sought to examine whether individuals perceive the consumption (i.e., viewing) of sexually-explicit material (SEM) as an act of infidelity. The study also looked into whether ethnicity, sexual orientation, religiosity, self-esteem, and femininity/masculinity influence this opinion. As an extension of the study, the participants' susceptibility for jealousy, general attitudes toward infidelity, attitudes toward SEM, opinion toward sexuality, and fear of abandonment were also analyzed. Social desirability was also used to find people's tendency to give socially desirable answers to questions related to sexuality. A statistical analysis of the study's results showed that religiosity significantly predicted opinions toward SEM as an act of infidelity. All other demographic values did not have significant predictability. An exploratory analysis showed that participants who think that viewing SEM is an acceptable behavior, are sexually liberal, use the internet for sexual purposes, and are less inclined to suffer jealousy in relationships were the most likely to believe that viewing SEM is not an act of infidelity.
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Date Issued: 2012
Identifier: CFH0004192, ucf:44846
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0004192

Title: Faculty Perceptions and Use of Web 2.0 Tools in Saudi Arabian Higher Education.
Creator: Alashwal, May, Campbell, Laurie, Hartshorne, Richard, Bai, Haiyan, Cox, Thomas, University of Central Florida
Abstract / Description: This study investigated factors that predict Saudi Arabian faculty members' intentions to adopt and use Web 2.0 tools and to assess faculty's awareness of the educational benefits of Web 2.0 tools to supplement classroom instructions in higher education. One hundred and three faculty members (34 male and 69 female) from a large university in the Western region of Saudi Arabia participated in the web survey. The framework and model for explaining and predicting the contributing factors towards...
Show moreThis study investigated factors that predict Saudi Arabian faculty members' intentions to adopt and use Web 2.0 tools and to assess faculty's awareness of the educational benefits of Web 2.0 tools to supplement classroom instructions in higher education. One hundred and three faculty members (34 male and 69 female) from a large university in the Western region of Saudi Arabia participated in the web survey. The framework and model for explaining and predicting the contributing factors towards the decision to adopt and use of Web 2.0 tools was the Decomposed Theory of Planned Behavior (DTPB). The partial least squares structural equation modeling (PLS-SEM) approach was utilized to analyze data collected from the web survey. Results indicate that positive attitudes and perceived usefulness are significant predictors of Saudi Arabian faculty members' intentions to use Web 2.0 tools. Moreover, findings indicate that Saudi Arabian faculty members intend to use Web 2.0 tools such as blogs, wikis, and social networking in their future classrooms to improve students' learning, student-student interaction, student-faculty interaction, and students' writing ability. Research implications for administrators and higher educational institutions indicate that professional development programs could be designed based on the significant predictors in the DTPB to support a successful integration of Web 2.0 tools in higher education.
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Date Issued: 2019
Identifier: CFE0007424, ucf:52695
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007424

Title: SYNTHESIS AND CHARACTERIZATION OF STABLE AND METASTABLE PHASES IN Ni- AND Fe-BASED ALLOY SYSTEMS BY MECHANICAL ALLOYING.
Creator: Al-Joubori, Ahmed, Challapalli, Suryanarayana, Vaidyanathan, Raj, Gou, Jihua, Bai, Yuanli, Lin, Kuo-Chi, University of Central Florida
Abstract / Description: Mechanical Alloying (MA) is a process that involves repeated cold welding, fracturing and rewelding of powder particles in a high-energy ball mill and has been used extensively to synthesize both stable (equilibrium) and metastable phases in a number of alloy systems. This is due to its ability to achieve many effects simultaneously, viz., reduction in grain size, introduction of a variety of crystal defects, disordering of the lattice, and modifying the crystal structures of materials; all...
Show moreMechanical Alloying (MA) is a process that involves repeated cold welding, fracturing and rewelding of powder particles in a high-energy ball mill and has been used extensively to synthesize both stable (equilibrium) and metastable phases in a number of alloy systems. This is due to its ability to achieve many effects simultaneously, viz., reduction in grain size, introduction of a variety of crystal defects, disordering of the lattice, and modifying the crystal structures of materials; all these allowing alloying and phase transformations to occur in powders. In this Dissertation, we have synthesized a number of different alloy phases in Ni- and Fe-based alloy systems using MA.The as-received, blended, and milled powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy techniques to obtain information about the overall microstructure and chemical compositions. The NiX2 (X = Ge and Si) phases were synthesized in the Ni-Ge and Ni-Si systems. MA of Ni-Ge powder blends was investigated to study phase evolution as a function of milling time. On milling the powders for 5 h, the equilibrium NiGe phase started to form, and its amount in the powder increased with increasing milling time. On milling for about 60 h, the equilibrium intermetallic NiGe and Ge powder particles reacted to form the metastable NiGe2 phase. However, on milling for a longer time (75 h), the metastable phase transformed back to the equilibrium NiGe phase.Synthesis of the NiSi2 intermetallic phase depended on the Si content in the initial powder blend. For example, while in the Ni-60 at.% Si powder blend, only the NiSi phase was present homogeneously, the powder blend of the Ni-67 at.% Si composition contained the NiSi phase along with a small amount of unreacted Si. But in the Ni-75 at.% Si and Ni-80 at% compositions, the NiSi phase that had formed earlier (after 2 h of milling) and the remaining free Si powder reacted to form the equilibrium intermetallic NiSi2 phase. This constitution in the milled powder has been attributed to a partial loss of Si content during MA. Formation of Ni(Si) solid solutions with a solubility of about 18.2 at.% and 20.6 at.% for the Ni-75 at.% Si and Ni-80 at.% Si powder blends, respectively, was also achieved in the early stages of MA.In the Fe-C system, we were able to synthesize ferrite, cementite, and mixtures of the two phases. We were able to obtain the Fe-C solid solution phase (ferrite) with a BCC structure and the cementite phase with an orthorhombic structure in the eutectoid Fe-0.8 wt. % C composition, while a homogeneous cementite phase had formed at the higher carbon content of Fe-7.0 wt. % C after 30 h of milling time.In the case of the Fe-18Cr-xNi (x = 8, 12, and 20) system, the current investigation showed that the phase constitution depended significantly on the Ni content in the powder blend. Whereas mostly the martensite or the ferrite and austenite phase mixture was present at lower Ni contents, a completely homogeneous austenite phase was present in the alloy with 20% Ni.
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Date Issued: 2016
Identifier: CFE0006244, ucf:51059
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006244

Title: ORGANIZATIONAL SUPPORT, ORGANIZATIONAL CITIZENSHIP BEHAVIOR, AND PERCEIVED PERFORMANCE: ANALYSIS OF CRIME SCENE INVESTIGATION UNITS OF TURKISH NATIONAL POLICE.
Creator: Tongur, Aykut, Kapucu, Naim, University of Central Florida
Abstract / Description: Policing is more difficult than ever before in today's world since types of crime and criminal profiles change as a result of technological development and globalization. Police organizations should review their organizational and operational strategies to improve the fight against contemporary crimes and criminals. Behaviors and performance of police officers are very important in fighting crime. In this struggle, especially today, officers should exhibit organizational citizenship behaviors...
Show morePolicing is more difficult than ever before in today's world since types of crime and criminal profiles change as a result of technological development and globalization. Police organizations should review their organizational and operational strategies to improve the fight against contemporary crimes and criminals. Behaviors and performance of police officers are very important in fighting crime. In this struggle, especially today, officers should exhibit organizational citizenship behaviors and perform better. One of the most important factors affecting these two concepts in organizations is organizational support. The literature stresses the social exchange cycle and reciprocity rules in the relationships of organizations and their members. In this cycle, if the organization cares about its members and if members perceive that the organization is supportive, they feel obliged to behave positively, perform better, and help the organization to reach its goals and objectives. If they don't perceive organizational support, they won't care about the organization, either. Hypotheses were developed based on these assumptions in the literature. This study tested these assumptions in Crime Scene Investigation units of the Turkish National Police (TNP). Structural Equation Modeling (SEM) was used to analyze the relationships among variables of Perceived Organizational Support (POS), Organizational Citizenship Behavior (OCB), and Perceived Performance (PP). Measurement models for these three latent constructs were developed by deriving the indicators from the literature. Most earlier studies tried to figure out reasons of the OCB. This study has a different perspective that investigates both reasons and results of OCB. A survey was developed to measure the latent variables of the study, and 405 of approximately 3,000 Crime Scene Investigators in the Turkish National Police responded to the iv survey. Results of the study showed that the relationship between POS and OCB is positive and significant. This is consistent with the literature. The relationship between OCB and PP is also positive and significant, and this is also consistent with the literature. However, the relationship between POS and PP is negative and insignificant. This result contradicts the results of previous studies in the literature and can be attributed to the subjective nature of measuring individuals' perceptions. According to the literature, perceptions are subjective rather than objective; therefore, data coming from reports of individual perceptions may not reflect the actual situation. Demographic information of the participants served as the control variables of the study. Information about the education level, rank, age, gender, size of the unit, and tenure of the respondents was collected by way of the conducted survey, and the effects of these variables were analyzed on the endogenous variable of the study, Perceived Performance. This study found no significant relationships between these control variables and Perceived Performance. Therefore, all these control variables were removed from the Structural Equation Model of the study. This study revealed that the TNP needs to be more supportive toward its members in order to have officers show organizational citizenship behavior and perform better. The TNP should revise its policies, especially regarding rotations from one province to another, working hours, rewards, and overtime pay. These are all indicators of organizational support and will result in a higher performance level among officers.
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Date Issued: 2011
Identifier: CFE0004058, ucf:49124
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004058

Title: Factors Affecting Systems Engineering Rigor in Launch Vehicle Organizations.
Creator: Gibson, Denton, Karwowski, Waldemar, Rabelo, Luis, Kotnour, Timothy, Kern, David, University of Central Florida
Abstract / Description: Systems engineering is a methodical multi-disciplinary approach to design, build, and operate complex systems. Launch vehicles are considered by many extremely complex systems that have greatly impacted where the systems engineering industry is today. Launch vehicles are used to transport payloads from the ground to a location in space. Satellites launched by launch vehicles can range from commercial communications to national security payloads. Satellite costs can range from a few million...
Show moreSystems engineering is a methodical multi-disciplinary approach to design, build, and operate complex systems. Launch vehicles are considered by many extremely complex systems that have greatly impacted where the systems engineering industry is today. Launch vehicles are used to transport payloads from the ground to a location in space. Satellites launched by launch vehicles can range from commercial communications to national security payloads. Satellite costs can range from a few million dollars to billions of dollars. Prior research suggests that lack of systems engineering rigor as one of the leading contributors to launch vehicle failures. A launch vehicle failure could have economic, societal, scientific, and national security impacts. This is why it is critical to understand the factors that affect systems engineering rigor in U.S. launch vehicle organizations.The current research examined organizational factors that influence systems engineering rigor in launch vehicle organizations. This study examined the effects of the factors of systems engineering culture and systems engineering support on systems engineering rigor. Particularly, the effects of top management support, organizational commitment, systems engineering support, and value of systems engineering were examined. This research study also analyzed the mediating role of systems engineering support between top management support and systems engineering rigor, as well as between organizational commitment and systems engineering rigor. A quantitative approach was used for this. Data for the study was collected via survey instrument. A total of 203 people in various systems engineering roles in launch vehicle organizations throughout the United States voluntarily participated. Each latent construct of the study was validated using confirmatory factor analysis (CFA). Structural equation modeling (SEM) was used to examine the relationships between the variables of the study. The IBM SPSS Amos 25 software was used to analyze the CFA and SEM.
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Date Issued: 2019
Identifier: CFE0007806, ucf:52348
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007806

SEM (6)	+ -
Higher Education (2)	+ -
BlackBoard (1)	+ -
C-S-H (1)	+ -
CFA (1)	+ -

Characterization (1)	+ -
Chemical analysis (1)	+ -
Crime Scene Investigation (1)	+ -
Criminal Investigators (1)	+ -
Criminalistics (1)	+ -
Cybersecurity (1)	+ -
Data Envelopment Analysis (DEA) (1)	+ -
Decomposed Theory of Planned Behavior (1)	+ -
Discrimination of osseous and non-osseous materials (1)	+ -
Electric Sector (1)	+ -
FTIR (1)	+ -
Faculty Perceptions (1)	+ -
Fe-based (1)	+ -
Forensic anthropology (1)	+ -
GSR (1)	+ -
Incident Response (1)	+ -
Individual Performance (1)	+ -
LIBS (1)	+ -
Lead-Free (1)	+ -
Lead-based (1)	+ -
MANOVA (1)	+ -
Mechanical alloying (1)	+ -
Multicultural (1)	+ -
Ni-based (1)	+ -
OCB (1)	+ -

ETD Collection (12)	+ -
Honors Collection (2)	+ -

University of Central Florida (14)	+ -
Sigman, Michael (3)	+ -
Karwowski, Waldemar (2)	+ -
Negy, Charles (2)	+ -
Wan, Thomas (2)	+ -

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Al-Joubori, Ahmed (1)	+ -
Alashwal, May (1)	+ -
Bai, Haiyan (1)	+ -
Bai, Yuanli (1)	+ -
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Bridge, Candice (1)	+ -
Campbell, Laurie (1)	+ -
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Cassisi, Jeffrey (1)	+ -
Challapalli, Suryanarayana (1)	+ -
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KU, CHENG-HSIN (1)	+ -
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