Follow

• 

  City of Dayton Economic Development Incentive Programs: Costs and Benefits

  Stephen L. MacKell

  The City of Dayton Economic Development Office currently employs two unique incentive programs to attract businesses to grow and locate within the city limits. These programs cost the taxpayers significant amounts of money while also providing profits to our local economy in the form of a bolstered tax base for the city government. The goal of the thesis is to compare the two programs using two different cost benefit economic analysis methods and provide a recommendation for increased efficiency to the city based upon the results of the analysis.

• 

  Cognitive Appraisals in a Deception Task

  Steven A. Bare

  Cognitive appraisals of threat and challenge, identified and characterized by Blascovich and Mendes (2000), involve whether an individual feels as though he or she is able to overcome a task requiring significant effort. This can be understood as an elaboration of the fight-or-flight response, and as such, can be indicated by physiological responses. This experiment applies this cognitive appraisal paradigm to a deception task, in an attempt to improve on the polygraph test.

• 

  Competing Responsibly: Are Businesses Appropriately Balancing the Motive of Profit with the Social Responsibility of Upholding Human Rights?

  Elizabeth A. Mitchell

  Corporations are in constant competition with one another in order to expand revenue and survive in this modern economy, however, this often has a very negative impact on the rights of the individual and the rights of the worker. Those at the top are too quickly willing to exploit those at the bottom in order to drive competition and profits. This leads to both an increase in human rights abuses and a loss of corporate social responsibility. Corporate social responsibility is the duty of corporations to respect the individual, workers, families, and communities in their business practices. I examine how corporations are addressing social responsibility and how they have or have not progressed within the last dozen years in regards to their business practices. I also examine how the international community has reacted to bad business practices and what effects these reactions have on corporate responsibility.

• 

  Decisions, Decisions, Decisions: How Undecided, Second Year Students in the College of Arts and Sciences Engage in the Decision Making Process of Choosing a Major

  Angela Lucas

  Choosing an academic major is one of the first significant decisions college students make. The purpose of this study was to determine how students in the second year of their undergraduate education in the College of Arts and Sciences make a decision about a college major. This study utilized individual interviews with students enrolled at the University of Dayton to explore resources used, information gathered and influences consulted to help determine the decision-making process of these students. Results indicated that family, especially parents, were frequently consulted and had a considerable influence on the choice of major. Students also relied heavily on career considerations as well as self-reflection to determine their own interests and abilities. Most participants expressed that they felt an enormous amount of pressure, both internal and external, to make a decision, and felt a sense of relief once the decision was made. Implications of this study include the necessity for professionals working with undecided students, especially academic and career advisors, to allow those students to discover their own interests and abilities and how they connect with career options. These results can benefit the field of academic and career advising because those professionals can encourage students to think about important decisions they made in the past, to realize they are capable of making good decisions, and to use some of the same methods to choose a major.

• 

  Decoupling the Biomechanics of Locomotion and the Direction of Spatial Updating During Blind-walking Tasks

  Adam Barnas, Ellen J. Hart, Natalya N. Lynn, Lauren M. Pytel

  Spatial updating, or the process of keeping track of objects' locations relative to one's spatial position while moving is critical to a variety of navigation tasks. Although updating is likely to occur automatically during sighted walking, walking without vision requires imagined updating of spatial relationships that change concurrently with movement. In particular, dynamic spatial updating likely underlies accurate performance when blind-walking to previously seen targets, a task commonly used to assess distance perception (Rieser et al., 1990). Studies of imagined walking suggest that the biomechanical information from locomotion influences the accuracy of spatial updating and blind-walking (Kunz et al., 2009). As replications and extensions of previous research, we further investigated the role of biomechanical information in spatial updating by manipulating the biomechanics of locomotion and the direction of spatial updating during blind walking. In Experiment 1, participants viewed targets that were positioned directly in front of or behind them. Participants were instructed to walk without vision to the targets while spatially updating their position in the environment as they walked either forward to targets in front of them or backward to targets behind them. Consistent with previous results, participants were generally accurate in both forward and backward walking, suggesting that participants spatially update in a manner consistent with their direction of movement, even for backward locomotion. Experiments 2 and 3 attempt to decouple the biomechanics of walking and the direction of spatial updating. Between these experiments, participants will view targets located directly in front of them at different distance ranges. Participants will be instructed to either walk forward without vision to the targets while spatially updating or backward away from the targets while, at the same time, imagining themselves walking forward to the targets and spatially updating in a manner consistent with the imagined forward walking.

• 

  Defect-Free Slider-Crank Function Generation Including Position, Velocity, and Acceleration Specification

  Ali Almandeel

  The slider-crank linkage is ubiquitous in machinery, from the piston/connecting rod/crankshaft in an IC engine to the flywheel/connecting rod/ram of a mechanical press. Function generation is the method by which slider-crank linkages may be designed to have a desirable set of kinematic properties. The kinematic properties are defined by the curve that relates the rotation of the input link of the slider-crank to the distance of slide produced at the output. The well-established methodology for slider-crank function generation states that five points can be selected to generate one of these curves. The five point methodology does not guarantee that the resulting linkage includes an input link that is capable of a full rotation, a necessity in most practical problems. Moreover, the methodology can result in linkages containing circuit defects. The problems of required full rotation and of avoiding circuit defects are addressed in this research. This research also addresses constraints on velocities and accelerations in the design process.

• 

  Denatonium Benzoate Removal from Water Sources Using Oxidation with Chlorine

  Mariana E. Aboujaoude

  Denatonium benzoate (DB) is the bitterest substance in existence, and 0.05 ppm of the bittering agent in water is detectable by taste. The Consumer Specialty Products Association and Humane Society Legislative Fund agreed that antifreeze and engine coolant manufacturers would start adding a bittering agent to their products, and several states require DB addition to antifreeze and engine coolant to prevent accidental ingestion. Since 30 ppm of DB in water could cause the water to be unpalatable, a concern is that improper disposal or spillage of products with DB could lead to contamination of water sources used for drinking water through seepage or runoff. Research has shown that sandy soil would not inhibit DB seepage into drinking water sources. The research objective was to determine if oxidation could lower the DB concentration enough to make water palatable. Experiments evaluated DB removal using oxidation batch tests. Organic free water, groundwater, softened groundwater, and softened-settled groundwater were spiked with 70 ppm DB, and 2 ppm chlorine was added. DB concentrations were tested with a high-performance liquid chromatography instrument. The DB percent removal was 4.8% in groundwater with a pH of 6.3. DB removal was 2.9% for softened-settled water with a pH of 7.9. Waters with higher pH levels had less DB removal using chlorine oxidation in comparison to water with pH levels closer to 7. The exception to this was for the softened water with a pH of 9.3 where 7% DB removal occurred. DB may have sorbed to precipitates formed during softening, thus resulting in slightly more removal. DB removal using chlorine in organic-free water was 8.5%. Chlorine did not remove as much DB from natural water with organic matter as it did with organic-free water. Chlorine oxidation did not lower DB levels enough to make water palatable.

• 

  Design and Prototyping of a 3D Shape Changing Mechanism

  Joshua E. Nieman

  Rigid-body shape-changing mechanisms are composed of a set of links and revolute joints and have the capacity to morph between shapes when actuated. This project examines the challenges associated with the design of a mechanism for morphing from a ''U'' to a ''D''. The initial stage of designing a shape-changing mechanism is completed in two dimensions and yields a design containing a large number of links and joints. Moving this planar concept into a 3D, fully realizable device provides an additional set of design challenges. The stacking, or identifying the vertical ordering of the links, is the challenge. Without a thorough consideration of the motion of the device, links are likely to collide with each other or with joint axes. Stacking issues were identified and remedied via a 3D CAD program. The resulting mechanism was fabricated to provide proof of concept.

• 

  Detecting Changes in the Earth's Magnetic Field

  Andrew T. McQuillen

  This year the Earth is being subjected to a high amount of solar activity due to the sunspot cycle being close to its maximum. This has an effect on the Earth's magnetic field. While small, the magnetic flux was able to be detected using a magnetometer built from a pair of magnets and a mirror suspended from a nylon thread. A change in the magnetic field of the Earth causes a slight rotation of the magnet which can be detected using laser light reflected off the mirror into a detector.

• 

  Detecting Critical Signals in Sustained Visual Attention Tasks Using Simulated Radar Screens

  Adam Barnas, Nnimnoabasi E. Essien, Graham Lang, Giuseppe G. Miranda, Christian L. Sutphin

  Vigilance, or sustained attention, typically requires observers to monitor many signals for infrequent critical signals over extended periods of time (Warm, 2003). Infrequent signals, otherwise known as critical signals, are presented differently in some manner and less frequently than the more common and frequent neutral signals. Critical signals typically indicate impending danger that requires immediate action to be made by an observer. Past research posits that sustained attention during a vigilance task declines for some time and is most likely caused by mindlessness, or a withdrawal of attention from the monitoring task (Robertson et al., 1997). The present research investigated the ability of participants to detect changes in visual stimuli and the confidence in their ability to accurately identify critical signals. Participants were presented with sets of stimuli containing four arrows in a circle facing the same clockwise or counter-clockwise direction. Participants responded to the critical signal in the set, which was when one arrow faced the direction opposite to the other three. Participants were queried about their confidence in the accuracy of their detections after all critical and an equal number of neutral signals. Our expectation is consistent with the typical decline in attention over time; that is, confidence will also diminish as the vigilance task continues. The results of the present study can be applied to any situation requiring sustained monitoring of informational displays. For example, pilots and technicians are required to monitor streams of visual and auditory stimuli for prolonged periods of time where the consequence of not detecting a critical signal could be catastrophic. Understanding more about vigilance processes can help avoid disaster.

• 

  Developing a Valuation Based Portfolio of Dow Jones Stocks

  Patrick W. Hull, Benjamin F. Rudman

  In this study, we create a portfolio of Dow Jones stocks based on valuation rather than price of market cap weight. Our hypothesis is that giving higher portfolio weights to these stocks that are most undervalued will increase portfolio returns. Using a fair value index based on Morningstar fair value prices for each Dow Jones stock, we create a portfolio weighting model. Using the period of 2009-2011 for analysis, we compare the returns of the Dow Jones fair value portfolio to the Dow Jones weighted portfolio. We also divide this period into three sub periods; the rebound period (2009), the growth period (2010), and the trading range period (2011) and compare the performance of our Dow Jones fair value portfolio to the Dow Jones price weighted portfolio.

• 

  Development of a Sublimation-Inhibitive Coating for TAGS-85 Thermoelectric Material

  Brian L. Berger

  Radioisotope Thermoelectric Generators (RTGs) ' in use by NASA since the 1960s ' convert the heat of decaying nuclear fuel to electricity. RTGs are an ideal power source for space technology due to their reliability and long lifespan. TAGS-85, a material critical to the operation of these generators, has been found to degrade over long periods of time at high temperatures. This degradation leads to a decrease in the power being produced by the RTG, diminishing its reliability as a power source. This thesis seeks to create a coating to inhibit sublimation which can be applied to TAGS-85 before it is installed in the RTG. Several types of ceramic coatings were applied to samples, which were then subjugated to elevated temperatures for extended periods of time. Several analytic techniques were employed to gauge the effectiveness of the coatings at preventing TAGS-85 degradation.

• 

  Differential Expression of Genes Between Dorsal and Ventral Iris Undergoing Lens Regeneration in Notophthalmus viridescens Revealed by Next Generation RNA Sequencing

  Konstantinos Sousounis

  Notophthalmus viridescens, the red-spotted newt, shows great regenerate capabilities. They can regenerate their limbs, heart, tail and eye parts. Noteworthy, the eye lens can be regenerated after complete removal (lentectomy) from the dorsal iris. Thus, lens regeneration involves the change of iris cells to lens cells, a process called transdifferentiation. Ventral iris does not participate in the process and can serve as natural negative control. In order to study what genes are expressed during this remarkable process, we utilized high-throughput RNA-sequencing, a method that gives mRNA sequence information and corresponding expression in the tested samples. We used dorsal and ventral iris 4 and 8 days post-lentectomy, two major time points for cell cycle re-entry and dedifferentiation, respectively. Differential expression of more than 38,000 annotated genes was studied between dorsal and ventral iris at both these time points. Highly differentially expressed genes in the dorsal or ventral iris were validated using quantitative real-time polymerase chain reaction. Those genes were TBX5, UNC5B and FGF10 in the dorsal iris and VAX2, NTN1 and NR2F5 in the ventral iris. Genes up-regulated in dorsal or ventral iris were grouped based on gene ontology terms (GO) and fisher's exact test was used to determine over-represented GO in the dorsal or ventral iris. We found that GO related to gene regulation, cytoskeleton, cell cycle and immune response were enriched in the dorsal iris, whereas GO related to transposons were enriched in the ventral iris. This study showed differences between dorsal and ventral iris which account for dorsal iris' ability to regenerate the lens. In addition, we found markers that specify dorsal or ventral iris. Based on this valuable resource, functional future studies can elucidate the mechanism of lens regeneration which can shed light to potential therapeutic applications to higher vertebrates and eventually to humans.

• 

  Do Measures of Ocular Gaze Correlate with Subjective Ratings in Assessing Aesthetic Preferences for Faces?

  Adam Barnas, Daniel A. Hurlburt, Hannah L. Lieber, Paulina E. Rosequist, Margaret A. Wedell

  In evaluating an image, the medium in which it is presented (e.g., photography, painting, digital art), among other factors, impacts preference (Lacey et al., 2011). To this end, we set out to determine preference for faces in paintings compared to photographic renderings of paintings. A photographic rendering depicts the same content and arrangement of features that the painting includes. Paintings and photographs were chosen out of a larger stimulus pool in which participants viewed each image separately and provided scale ratings of beauty and aesthetic pleasingness. Mean ratings for these attributes were compared to mean ratings of similarity for the same paintings and photographs that had been matched and presented together. Consequently, stimuli rated high in similarity, beauty, and aesthetic pleasingness were selected for a subsequent study. For this study, participants will evaluate faces in paintings and photographic renderings of paintings, as well. However, they will provide subjective ratings of aesthetic pleasingness, similarity and perceived value of the stimuli while head-mounted cameras record measures of ocular gaze (i.e., visual scan paths, fixation times, and pupil dilations). We predict that faces in paintings will be rated higher in aesthetic pleasingness as compared to the photographic renderings because of the perceived artistic value of the paintings. Furthermore, we expect subjective ratings to correlate with measures of ocular gaze directed toward features that determine aesthetic value and preferences for faces in paintings versus faces in photographs. Results from this study have implications in marketing and product development, as well as improving our understanding of what is considered art and how it adds to perceived value. Furthermore, the use of physiological measures, such as those of ocular gaze, along with the ubiquitous subjective ratings stands to illuminate better the intimate relationship between body and mind.

• 

  Eating Disorder Diagnoses and Treatments: The Impact of an Educational Symposium

  Hannah J. Lowe, Meredith N. Schlabig

  The purpose of this study was to assess the impact of "Eating Disorder Diagnoses and Treatments: An Educational Symposium," a one-day event that was held at the University of Dayton on November 3, 2012. The goals of this symposium were to increase the attendees' knowledge about eating disorders and to improve their attitudes toward individuals with these disorders. The symposium was composed of presentations by health and mental healthcare professionals who shared research, statistics, case studies, and anecdotes and artifacts from their clinical experience. Speakers included a Psychologist, a Board-Certified Music Therapist, a Licensed Registered Dietitian, and a Registered and Board-Certified Art Therapist. In addition, a UD Music Therapy major shared personal testimony related to her own experiences of battling an eating disorder. Symposium attendees were invited to voluntarily and anonymously complete a 5-question survey that assessed knowledge and attitudes related to eating disorders and their treatments. Participants completed the survey both prior to and after attending symposium sessions. Five 5-point Likert scales captured attendees' 1) knowledge about diagnoses, 2) knowledge about treatment, and the degree to which they were 3) judgmental, 4) concerned, and 5) sympathetic toward individuals with eating disorders. Survey results indicate an encouraging trend: In general, respondents--even those who attended only a portion of the symposium--reported increases in knowledge about eating disorders and positive changes in attitudes toward those affected by these disorders. Specific results will be presented, along with plausible interpretations of findings, study limitations, and suggestions for future research pertaining to eating disorders.

• 

  Education in Dayton; A Social Justice Service Club Project

  Stephanie F. Bartol, Mary M. Cook, Pamela R. Malone, Kelsey L. Radabaugh

  As members of the Social Justice Service Club, we are committed to the ideal of improving literacy in the surrounding Miami Valley Community. This project represents the culmination our service learning project for 2012-2013. For the past two semester we have tutored children in lower socioeconomic situations. We believe that a retrospective look at our service will not only feature the benefit of tutoring children who are struggling with basic literacy, but will promote an educational awareness of the seriousness of the issue that is in our own neighborhoods in the Miami Valley. Literacy is first and foremost a social justice issue. Our research is significant because it will demonstrate that by engaging these children at an early age and promoting literacy on a one-on-one basis we can be agents of change and models of the Marianist ideals of lead, learn and serve.

• 

  EEG Action Encoding

  Theus H. Aspiras, Kelly Cashion, Carly A. Gross

  The Electroencephalograms (EEGs) Action Encoding is focused on translating the EEG signals into actions such as lift, turn, grab, drop, pull, push, and so on. This research has many possible applications, but more research must be done in order to turn these ideas into a reality. It could help the handicapped use robots to complete various tasks. It could also be used to communicate with coma patients. The robots could be controlled by thoughts to accomplish tasks too dangerous for humans. In order to translate the thoughts into actions, a program will be trained to recognize patterns in the EEG that are associated with one of these actions. Multiple challenges include variations in thought patterns between people and differences in thought patterns between thinking about and actually performing an action. An appropriate plan to collect and translate the data has been formulated. The patient will be fitted with the Data Acquisition Device and their brainwaves will be collected while they perform various tasks. This data will be filtered to remove noise and eye blinks, and then used to train the program.

• 

  Effect of Compliant Flooring on Postural Stability in an Older Adult Population

  Renee L. Beach

  Balance, or the ability to stand upright unassisted without falling, is affected by the brain's ability to process sensory information from an individual's vision, muscles, and joints. Researchers have studied how elderly patients often have problems in these systems and therefore struggle with balance putting them at higher risk of falling. Since older individuals with postural instability are up to 5 times more likely to fall, environmental changes to decrease amount of falls and fall related injuries is vital. Compliant flooring is a novel approach shown to reduce the amount of injuries from falls by absorbing up to 50% of the impact from a fall. The purpose of this study was to analyze whether these newer floorings had the tradeoff of negatively affecting balance and functional movement due to their compliance. 20 healthy older adults underwent static balance testing as well as functional balance testing. Participants were instructed to stand on three different types of flooring, performing the tasks of sitting to standing, turning in a circle, putting on a sweater, picking up an object, standing still with eyes open, standing still with eyes closed, and leaning at the ankle forward, backward and side-to-side. A force platform and inertial measurement units (IMUs) were used to record center of pressure (COP) and trunk kinematics. Medial/Lateral (M/L) and Anterior/Posterior (A/P) COP sway range and Time to Stabilization (TtS) were among the variables calculated. Initial results show significantly increased A/P postural sway (p<0.05) on the compliant flooring, with eyes open and eyes closed. No statistically significant differences were found in sway ranges during the Limits of Stability task. This work will help living communities with individuals at high fall risk, such as nursing homes, be better informed of options for preventing injuries due to falls.

• 

  Effects of Sustained Attention on Auditory Displays, Mental Workload, and Stress

  Adam Barnas, Nnimnoabasi E. Essien, Graham Lang, Giuseppe G. Miranda, Christian L. Sutphin

  Vigilance can be defined as the sustained attention required in detecting transient and infrequent signals over an extended period of time (Warm, 2003). The current research defines these infrequent signals as critical signals in order to demonstrate that their appearance marks some kind of unfavorable event. Typically, these experiments focus on the display of either or both auditory and visual stimuli. However, in the study described here, two experiments study only auditory stimuli. The first experiment manipulates the duration of an auditory tone using two tones of equal loudness that last for different lengths of time. In this instance, the critical signal is the tone with the shorter duration. The second experiment manipulates the spatial location of auditory tones, using the same type of tone. Although, the tones are of equal duration, they are spatially presented at different locations in auditory space around the head of a perceiver. In this instance, the critical signal will be the tone that is off-center in relation to the head and heard mainly in one ear. The relevance of this research is that many professions (e.g., air traffic control) require sustained monitoring to detect changes in signals, including auditory tones. There is a potential for catastrophic events, such as the fatal crash of an airplane, if a critical auditory signal is missed by an air traffic controller. Therefore, studies of the factors affecting the monitoring of auditory signals will continue to focus on the ability of people to accurately perform sustained attention tasks.

• 

  Enhancement of Images Captured in Complex Lighting Environments for Visual Quality Improvement

  Sai Babu Arigela

  The effectiveness of an image enhancement technique based on a sine nonlinear transformation function to improve the visual quality of images captured with low dynamic range devices in extreme lighting conditions is presented. The enhancement technique consists of four processes: histogram adjustment, dynamic range compression, contrast enhancement and nonlinear color restoration. Histogram adjustment on each spectral band is performed to minimize the effect of illumination. Dynamic range compression is accomplished by a sine nonlinear function with an image dependent parameter to tune the intensity of each pixel in the luminance image. A nonlinear color restoration process based on the chromatic information and luminance of the original image is employed. The effectiveness of this technique is evaluated on various natural images and aerial images, and compared with other state-of the art techniques. A quantitative evaluation is performed by estimating the number of Harris corners and Speeded Up Robust Features (SURF) on wide area motion imagery data. The application of the proposed algorithm on face detection is also demonstrated. The evaluation results demonstrate that the proposed method holds significant benefits for surveillance and security applications and also as a preprocessing technique for object detection and tracking applications.

• 

  Evaluation of Multiaxial Fatigue Models for Ti-6Al-4V

  Christopher A. Buck

  The fatigue life of an engineering component is often an important design consideration, but the understanding of this property is somewhat limited. Engineering components often experience stresses due to cyclic multiaxial loads, which eventually cause fatigue failure. The majority of research into fatigue failure, however, has been devoted to modeling and predicting the fatigue life of components subjected to uniaxial loading. Uniaxial loading is easier to test and understand than multiaxial loading, but it is not as likely to occur in applications as multiaxial loading. Several approaches to modeling multiaxial fatigue life have been developed, including the Sines Model and the Findley Model. In order to test the validity of each model, reliable multiaxial fatigue test equipment is required to generate accurate data. Past efforts have attempted to validate multiaxial fatigue life models, but were performed without the benefit of reliable test data. Recently, the Air Force Research Laboratory obtained a MTS 809 Axial/Torsional Test System that is capable of generating accurate multiaxial fatigue data. Throughout this project, the MTS tension-torsion machine was used to generate reliable torsional and multiaxial fatigue data for Ti-6Al-4V test specimens. The data generated by the torsional fatigue tests was used in conjunction with previously generated axial fatigue data to model and predict the fatigue life of Ti-6Al-4V test specimens subjected to multiaxial loading. The MTS tension-torsion machine was the used to test Ti-6Al-4V test specimens under multiaxial loading. The fatigue life of the test specimens subjected to multiaxial loading was then compared to the fatigue life predicted by the models to evaluate how effectively each model predicted the fatigue life of Ti-6Al-4V.

• 

  Extracting Context Information from Aerial Imagery for Aiding Threat Detection

  Varun Santhaseelan

  Advances in computer vision have led to development of algorithms that are able to extract semantic information from images/video in order to make high level inferences from data. One of the major steps toward extracting semantic information is to identify useful contextual information present in the scene. In this research, we present a novel technique to extract context information from aerial imagery using concatenated vectors of low level features. The objective of this research is to aid in the identification of threats along the right of way of energy pipelines. The key observation of this research is that aerial imagery consists of various image segments like roads, buildings and trees along with lots of plain ground. All aforementioned segments of the image have definitive properties in terms of low level features. The information content present in plain ground is minimal when compared to other regions in the image. This characteristic was exploited to have a simple thresholding procedure designed on the basis of relative variance and entropy for fast background elimination. Trees are rich in textural content, buildings have higher contrast information and roads have discriminative color features. In this research we have extracted local phase information and local contrast information using the monogenic signal model. These features are used to train a support vector machine (SVM) which is then used for classification. In order to refine the segmentation process, we apply morphological operations on the result of the classifier. We present the results obtained by using the proposed method on various data sets captured using different camera sensors.

• 

  Fabrication of Low-Cost Flow Cell and Tapered Optical Fibers for Aqueous Biosensing

  Marika S. Edwards, Dillon T. Grandinette, Branden J. King, Jonathan B. Melendez

  This study focuses on the engineering and design of a biconic, tapered optical fiber platform for biosensing applications. The sensor platform consists of a machined polytetrafluoroethylene (Teflon, PTFE) flow cell which is chemically inert, easily machined, and available at low-cost. The flow cell was designed to withstand temperatures of 0 to 60 degrees Celsius, to protect the fragile, tapered fiber, and connected to a syringe pump to allow for the introduction of aqueous solutions for surface chemistry functionalization and analyte exposures. The flow system was used to characterize individual single-mode or polarization-maintaining fibers that were tapered to a waist diameter of approximately 10 microns. Signal was measured as the amount of light transmission through the tapered fibers. Preliminary results obtained for antibody-antigen interactions indicate that molecular interaction of the antigen with the surface-tethered antibody results in a change in the quantity and phase of light passing through the tapered fiber.

• 

  Four-bar Linkage Synthesis for A Combination of Motion and Path-point Generation

  Yuxuan Tong

  The goal of this project is the development of techniques that helps address the design of pick-and-place machines. Pick-and-place, common in assembly and manufacturing tasks, refers to the action of retrieving a part at one location and transporting (and reorienting) it to a second location. Pick-and-place tasks have rigid end-of-motion requirements needing exact positions and orientations. Between these end configurations, the motion restrictions are less rigorous. This challenge is addressed via GCP and the development of new design theory. Geometric Constraint Programming (GCP), adept in addressing kinematic synthesis challenges, is the set of tools available in any CAD package that allows for the specification of relationships between line segments, while allowing the lengths of those line segments to be variable. New design theory has identified the equations that effectively describe pick-and-place problems and resulted in new solution methodologies.

• 

  Fundamental Mathematical Model for Direct Write Additive Manufacturing

  Robert J. Strong

  Direct write additive manufacturing processes are seeing a growing number of applications. This work specifically focuses on one of the most versatile direct write technologies, a continuous bead extrusion process. A syringe type mechanism is used to deposit a bead of a liquid ink on a surface. Two and three dimensional structures can be fabricated through the x-y motion of the print head and the z motion of the build surface. A mathematical model describing the spreading of a printed bead of ink or other liquid has been developed. The model accounted for surface tension forces acting on the bead and neglected gravitational effects. Any changes in density or viscosity of the bead during the print process were also neglected in this first generation model. The model provides a useful tool for direct write process design as well as for the development of new ink formulations.