Twenty-first century skills are important for secondary students to experience during school. The purpose of this qualitative study was to gauge the perception of senior students regarding their exposure to the Virginia 5C's (5C's) and the 21st century skills through a senior project experience. The central research question was, Did the senior project at a rural high school in Virginia expose students to the 5C's and 21st century skills? According to the Virginia Board of Education, the 5C's (critical thinking, creative thinking, collaboration, communication, and citizenship) are essential for every public high school student to learn. The 5C's have been incorporated into all public high schools in Virginia, beginning with the freshmen class of 2018-2019. Information was gathered to identify improvements that could be made to a senior project at a public secondary school to determine if 21st century skills and the 5C's were exposed. The senior project coursework included an introduction to 21st century skills and the 5C's, resume workshop, interview training, and an actual interview. Seniors worked 30 minutes each day with an instructor that totaled 2 hours for the senior project experience. After completion of the senior project, 22 students voluntarily completed an electronic survey that contained 12 questions. Results were analyzed and four specific findings were evident. Participants agreed that the senior project exposed them to the 21st century skills and the 5C's. Although the researcher could not prove that the students are better prepared for post-graduation because of the senior project, participants agreed to the survey question that the senior project helped better prepare them for post-graduation. Also the participants agreed that they enjoyed the senior project overall. The results of this study could support leaders with implementing a senior project if the desired outcome is for students to gain knowledge of the 5C's and 21st century skills. / Doctor of Education / Twenty-first century skills are important for secondary students to experience during school. The purpose of this qualitative study was to gauge the perception of senior students regarding their exposure to the Virginia 5C's (5C's) and the 21st century skills through a senior project experience. The central research question was, Did the senior project at a rural high school in Virginia expose students to the 5C's and 21st century skills? According to the Virginia Board of Education, the 5C's (critical thinking, creative thinking, collaboration, communication, and citizenship) are essential for every public high school student to learn. The 5C's have been incorporated into all public high schools in Virginia, beginning with the freshmen class of 2018-2019. Information was gathered to identify improvements that could be made to a senior project at a public secondary school in the western portion of Virginia to determine if 21st century skills and the 5C's were successfully addressed. After completion of the senior project, 22 students voluntarily completed an electronic survey that contained 12 questions. Results were analyzed and it was found that the overall senior project experience exposed students to the 5C's and 21st century skills. Although the researcher could not prove that the students are better prepared for post-graduation because of the senior project, participants agreed to the survey question that the senior project helped better prepare them for post-graduation. Also the participants agreed that they enjoyed the senior project overall.

The first aim of this work was to integrate, validate, and document, a digital particle image quantification (Flow-IQ) software package developed in conjunction with and supported by Aeroprobe Corporation. The system is tailored towards experimental fluid mechanics applications. The second aim of this work was to test the performance of DPIV algorithms in wall shear flows, and to test the performance of several particle sizing algorithms for use in spray sizing and average diameter calculation. Several particle sizing algorithms which assume a circular particle profile were tested with DPIV data on spray atomization, including three point Guassian, four point Gaussian, and least squares algorithms. A novel elliptical diameter estimation scheme was developed which does not limit the measurement to circular patterns. The elliptic estimator developed in this work is able to estimate the diameter of a particle with an elliptic shape, and assumes that the particle is axisymmetric about the x or y axis. Two elliptical schemes, the true and averaged elliptical estimators, were developed and compared to the traditional three point Gaussian diameter estimator using theoretical models. If elliptical particles are theoretically used, the elliptical sizing schemes perform drastically better than the traditional scheme, which is limited to diameter measurements in the x-direction. The error of the traditional method in determining the volume of an elliptical particle increases dramatically with the eccentricity. Monte Carlo Simulations were also used to characterize the error associated with wall shear measurements using DPIV. Couette flow artificial images were generated with various shear rates at the wall. DPIV analysis was performed on these images using PIV algorithms developed by other researchers, including the traditional multigrid method, a dynamically-adaptive DPIV scheme, and a control set with no discrete window offset. The error at the wall was calculated for each data set. The dynamically adaptive scheme was found to estimate the velocity near the wall with less error than the no discrete window offset and traditional multigrid algorithms. The shear rate was found to be the main factor in the error in the velocity measurement. In wall shear velocity measurement, the mean (bias) error was an order of magnitude greater than the RMS (random) error. A least squares scheme was used to correct for this bias error with favorable results. The major contribution of this effort stems from providing a novel elliptical particle sizing scheme for use in DPIV, and quantifies the error associated with wall shear measurements using several DPIV algorithms. A test bed and comprehensive user's manual for Flow-IQ v2.2 was also developed in this work. / Master of Science

A major challenge in tire, as well as in road engineering, is to understand the intricate mechanisms of friction. Pavement texture is a feature of the road surface that determines most tire-road interactions, and can be grouped into two classes: macro-texture, resulting mainly in the hysteretic component of friction, and micro-texture, resulting in adhesion. If both textures are maintained at high levels, they can help provide sufficient resistance to skidding. The ultimate objective of this research is to develop a physics-based multiscale rubber-road friction model that can predict the effectiveness of the tire as it interacts with the vehicle and the pavement. The model is developed based on sound physics and contact mechanics theories and uses road profile measurements and data measured on various tire compounds. To be able to predict road surface characteristics, it is proven that road surfaces are of fractal nature on given ranges of scale. It is shown that while global fractal quantities fail to classify pavement profiles, a local fractal parameter and three other texture parameters can separate road profiles that have different friction characteristics. Through the implementation of various contact theories and by conducting simulation studies, a methodical understanding of contact mechanics and of the effect of the diverse factors that influence friction is attained. To predict the viscoelastic friction between any given tire tread compound and road, the Nanovea JR25 portable optical profilometer is used to measure the road profiles. To characterize the road profile, the one-dimensional pavement measurements are used to obtain the two-dimensional power spectrum, followed by testing and characterizing the tread compounds (this is being carried out by Bridgestone). This data is used to develop a comprehensive analytical methodology to predict friction. To validate this model, a Dynamic Friction Test apparatus is designed and built. The friction tester enables measurement of the friction between tread compound samples and arbitrary surfaces, at different slip ratios. The correlations between the simulations and both indoor and outdoor experimental results are investigated. / Ph. D.

This thesis compared macrotexture measurements obtained using the volumetric method (Sand Patch) and three laser-based devices: MGPS system, ICC laser profiler, and Circular Texture Meter (CTMeter). The study used data from three sources: two controlled experiments conducted at the Virginia Smart Road, field data collected on eight newly constructed hot-mix-asphalt (HMA) roadway surfaces, and data collected on airport surfaces at the Wallops flight facility, Virginia. The data collected at the Virginia Smart Road, a controlled-access two-lane road that includes various HMA and concrete surfaces, was used for the main analysis. The other two sets of data were used for verification and validation of the model developed. The analysis of the data collected at the Virginia Smart Road showed that the CTMeter mean profile depth (MPD) has the highest correlation with the volumetric (Sand Patch) mean texture depth (MTD). Furthermore, texture convexity had a significant effect on the correlation between the measurements obtained with different devices. Two sets of models for converting the laser-based texture measurements to an estimated MTD (ETD) were developed. One set of equations considered all the data collected at the Virginia Smart Road, and the other excluded the measurements on the Open-Graded Friction Course (OGFC). The developed models were tested using measurements collected at eight roadway sections throughout Virginia and the Wallops flight facility. The model, excluding the OGFC section, was successfully applied to other sites. / Master of Science

For decades, the pavement engineering community has continued to drive improvements in accuracy and repeatability of terrain measurement systems. Traditional terrain measurement systems are tailored for a measuring a specific scale and resolution and hence application scope. These systems tend to focus on surface roughness alone and reject either fine macrotexture or large-scale global features. This work proposes a novel improvement to the terrain measurement system, by increasing the capability to measure the terrain surface at a variety of scales. By increasing the scales of measurement, desired aspects of the terrain profile can be accurately obtained for a wide variety of applications without having to omit large-scale features or macrotexture. In addition to increasing the capabilities of the traditional terrain measurement system, methods for addressing and minimizing sources of error within the system are developed. Major sources of error in terrain measurement systems, which compromise the accuracy and repeatability of the resulting measured terrain, include scanning laser uncertainty, inertial navigation system (INS) uncertainty and drift, triggering and time synchronization, system misalignment, and post-processing errors. These errors are addressed, and an improved Vehicle Terrain Measurement System (VTMS) is proposed. A triggering and time synchronization system is developed and insight into the development of this system for a terrain measurement system is gained. All three scanning lasers are individually assessed for linearity, with sample profiles analyzed for agreement. The improved VTMS represents a significant development in terrain measurement systems. / Master of Science

Ultrawideband (UWB) is one of the most promising communication technologies in recent times with the promise of high data rates and spectral reuse. This work analyses the outdoor and outdoor-to-indoor propagating characteristics of the UWB pulse, which can be of the order of a few gigahertz in bandwidth. The aim of the thesis is to provide the parameters needed in order to develop a channel model for such cases. The channel model would then play an important role in determining physical layer (PHY) solutions to optimally exploit these characteristics. The measurements carried out on the Virginia Tech campus are used to compute parameters such as path loss, penetration loss and delay statistics. These are carried out in multiple frequency bands and the results are compared across frequency bands to determine effect of different frequency levels on the parameters. Finally the results are analyzed with respect to similar parameters obtained in other measurement campaigns in an attempt to evaluate the performance of Ultrawideband vis-à-vis narrowband systems. / Master of Science

The emergence of high-fidelity vehicle and tire models has raised the requirements for terrain measurement capabilities. Inaccuracies that were once tolerable for measurement of general terrain roughness are no longer acceptable for these new applications. The techniques in this work seek to improve the quality of terrain measurement in addition to providing an objective way to describe the accuracy of these measurements. The first portion of this work develops an accuracy verification procedure for terrain measurement systems. This procedure involves a static test to assess the limitations of the profiler's laser height sensor, and a corresponding dynamic test to evaluate the limitations of the positioning sensors. Even with a well calibrated system, inertial errors will accumulate. The second portion of this work develops techniques to address these inertial errors in the data post-processing phase. A general correction technique is developed for any terrain type and a more computationally efficient technique is developed for smooth surfaces. For basic ride and handling simulations, 3D terrain surfaces are computationally impractical, as the models used for these simulations only require point excitation. Current road profilers acquiring these 2D data use single-point lasers that capture localized disturbances that would be mechanically filtered by the tire and suspension in the physical vehicle system. The final chapter in this work develops a method to extract a 2D terrain profile from a 3D terrain surface. By considering all of the information in the tire contact patch, the filtering properties of the tire are approximately emulated. / Master of Science

The National Aeronautics and Space Administration (NASA) is considering the use of iodine for disinfection of recycled wastewater and potable water in the International Space Station (ISS). Like Chlorine and other halogen compounds, iodine can form disinfection by-products (DBPs) in the presence of organic compounds. Recycled wastewater sources proposed for reuse in the space station include laundry, urine, and humidity condensate. These contain large concentrations of iodine-demanding compounds, including phenol (Barkely et al., 1992). Therefore, the potential for the formation of iodine disinfection by-products (IDBPs) is of concern. Based on the characteristics of the ISS recycled wastewater sources and potable water treatment system, a series of experiments was designed to evaluate the formation of IDBPs under different experimental conditions. Studies were conducted by reacting various concentrations of iodine with phenol at pH 5.5 and 8.0.Iodine concentrations of 10 and 50 mg/L and phenol concentrations of 5 and 50 mg/L were used. Reactions were monitored for up to 32 days for the formation of IDBPs. All reactions were maintained at 20 C in dark. High Performance Liquid Chromatography (HPLC) and Gas Chromatography/Mass Spectrometry (GC/MS) were used for identification and quantitative analysis of phenolic compounds. Spectrophotometry was used to monitor the iodine concentrations. Falvor Profile analysis (FPA) method was used to evaluate the odor characteristics of the phenolic compounds. Reactions of iodine with phenol resulted in the formation of the following by-products: 2-iodophenol, 4-iodophenol, diiodophenols, and 2,4,6-triiodophenol. Most reaction conditions studied resulted in the formation of all or some of the specified iodophenols. The initial mass ratio of iodine to phenol was the major determining factor in the concentrations and types of by-products formed. The IDBPs were formed within one hour after initiation of the reactions. Extended reaction times did not lead to significant increases in the concentration of IDBPs. Under most reaction conditions, mono-subsituted phenols were detected at significantly higher concentrations than di-substituted phenolic compounds; triiodophenol was the major by-product when iodine:phenol mass ratio was 10:1. The greatest number of IDBPs were formed when reaction solutions consisted of 1:1 mass ratio of iodine to phenol. FPA panel indicated the odor threshold concentrations for phenol, 2-iodophenol, and 4-iodophenol were 5 mg/L, less than 1 ug/L, and 1 mg/L respectively. The most common odor descriptions for all these compounds were "chemical", "phenolic", and "medicinal". / Master of Science

Individuals with Social Anxiety Disorder (SAD) are typically perceived by others as shy, submissive, or risk-averse. However, recent work has identified an understudied subtype within SAD characterized by high levels of anger and high-risk or novelty-seeking impulsive behaviors. Interestingly, this subtype bears conceptual similarities with prior accounts of vulnerable narcissism. For example, both are associated with concerns regarding self-presentation and how they are perceived by others. The angry-impulsive subtype and vulnerable narcissism may further share similar etiologic origins and similar associations with self-reported anger, impulsivity, and anxiety-related characteristics. However, despite these key similarities no prior work has systematically evaluated the common and potentially distinguishing factors within and between these conceptually similar but diagnostically distinct groups. For example, cognitive features such as fear of negative evaluation and interpersonal rivalry could be distinguishing features of SAD and vulnerable narcissism, although the utility of these distinguishing features to clarify the differential diagnosis remains unknown. Accordingly, the purpose of this study was to utilize a person-centered analytic approach (latent profile analysis; LPA) to empirically establish whether vulnerable narcissistic traits exist within high anger, risk-prone individuals who are also socially anxious, or alternatively whether specific features of each disorder can be used to disambiguate them empirically. Results of this work supported the existence of the angry impulsive socially anxious subtype and supported a relationship between that group and vulnerable narcissistic traits. These findings have implications for treatment selection among affected individuals and may further clarify why prior work evaluating interventions for adults with SAD and angry impulsive features has been met with only limited success. / M.S. / Individuals with Social Anxiety Disorder (SAD) are typically perceived by others as shy, submissive, or risk-averse. However, recent work has identified an understudied subtype within SAD characterized by high levels of anger and high-risk or novelty-seeking impulsive behaviors. Interestingly, this subtype has conceptual similarities with descriptions of vulnerable narcissism. For example, both are associated with concerns regarding self-presentation and how they are perceived by others. The angry-impulsive subtype and vulnerable narcissism may further share similar origins and similar associations with self-reported anger, impulsivity, and anxiety-related characteristics. However, despite these key similarities no prior work has evaluated the common and potentially distinctive factors within and between these distinct groups. For example, features such as fear of negative evaluation and interpersonal rivalry could be distinguishing features of SAD and vulnerable narcissism, although the utility of these differentiating features to clarify the differential diagnosis is unknown. Accordingly, the purpose of this study was to utilize a person-centered analytic approach (latent profile analysis; LPA) to establish whether vulnerable narcissistic traits exist within high anger, risk-prone individuals who are also socially anxious, or whether specific features of each disorder can be used to differentiate them. Results of this work supported the existence of the angry impulsive socially anxious subtype and supported a relationship between that group and vulnerable narcissistic traits. These findings have implications for treatment selection among affected individuals and may further clarify why prior work evaluating interventions for adults with SAD and angry impulsive features has been met with only limited success.

This thesis aims towards devising a non-destructive testing methodology for ICs fabricated by a third party manufacturer to ensure the integrity of the chip. With the growing trend of outsourcing, the sanity of the final product has emerged to be a prime concern for the end user. This is especially so if the components are to be used in mission-critical applications such as space-exploration, medical diagnosis and treatment, defense equipment such as missiles etc., where a single failure can lead to a disaster. Thus, any extraneous parts (Trojans) that might have been implanted by the third party manufacturer with a malicious intent during the fabrication process must be diagnosed before the component is put to use. The inherent stealthy nature of Trojans makes it difficult to detect them at normal IC outputs. More so, with the restriction that one cannot visually inspect the internals of an IC after it has been manufactured. This obviates the use of side-channel signal(s) that acts like a signature of the IC as a means to assess its internal behavior under operational conditions. In this work, we have selected power as the side-channel signal to characterize the internal behavior of the ICs. We have used two circuit partitioning based approaches for isolating and enhancing the behavioral difference between parts of a genuine IC and one with a sequence detector Trojan in it. Experimental results reveal that these approaches are effective in exposing anomalous behavior between the targeted ICs. This is reflected as difference in power-profiles of the genuine and maligned ICs that is magnified above the process variation ensuring that the discrepancies are observable. / Master of Science